Hyderabad, India

The Indian Institute of Chemical Technology is a national-level research center located in Hyderabad, Telangana, India under the Council of Scientific and Industrial Research . IICT conducts research in basic and applied chemistry, biochemistry, bioinformatics, chemical engineering and provides science and technology inputs to the industrial and economic development of the country. IICT has filed one of the maximum CSIR patents. Wikipedia.


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Yadav J.S.,Indian Institute of Chemical Technology | Dhara S.,Indian Institute of Chemical Technology | Mohapatra D.K.,Indian Institute of Chemical Technology
Tetrahedron | Year: 2017

A stereoselective total synthesis of 10-epi-tirandamycin E is described, employing desymmetrization protocol, ring-closing metathesis (RCM), acid-catalyzed ketalization, substrate controlled dihydroxylation and Horner-Wadsworth-Emmons olefination as key reactions. © 2017 Elsevier Ltd


Krishna Moodapelly S.,Indian Institute of Chemical Technology | Sharma G.V.M.,Indian Institute of Chemical Technology | Ramana Doddi V.,Indian Institute of Chemical Technology
Advanced Synthesis and Catalysis | Year: 2017

The nucleophilic reactivity of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was completely controlled by the formation of monohydrate (DBU H2O) in the synthesis of 1-(bromoethynyl)arenes from 1,1-dibromoalkenes. Differential reactivity of DBU in protic solvents as compared to aprotic solvents has been explored to prevent the formation of mixtures of products in this reaction. Hydrated DBU is found to be superior to dry DBU, both for the selective synthesis and ease of isolation. In addition, use of DBU H2O as a non-nucleophilic mild base allowed us to synthesise 1-(bromoethynyl)arenes via a reaction under solvent-free conditions. Utilization of DBU H2O as sole reagent also allowed us to isolate the products without column chromatographic purifications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Jena B.K.,Indian Institute of Chemical Technology | Reddy G.S.,Indian Institute of Chemical Technology | Mohapatra D.K.,Indian Institute of Chemical Technology
Organic and Biomolecular Chemistry | Year: 2017

The first asymmetric total synthesis of a 16-membered macrolide, aspergillide D, is described. The chiral centers of the acid are derived from d-ribose and the alcohol subunit from 1,8-octane diol through Sharpless kinetic resolution, respectively. The other key reactions include Yamaguchi esterification, ring-closing metathesis reaction, and Shiina macrolactonization to construct the fully functionalized macrocycle. © The Royal Society of Chemistry.


Vinaykumar A.,Indian Institute of Chemical Technology | Muniraju C.,Indian Institute of Chemical Technology | Rao B.V.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2017

Total synthesis of (-)-zeylenol, a key intermediate for the synthesis of (+)-pipoxide, (-)-uvarigranol G and (-)-tonkinenin A was achieved from commercially available starting material d-mannose. The key steps are mixed aldol condensation, Grignard reaction, ring closing metathesis and regioselective benzoylation. © 2017 Elsevier Ltd.


Ramesh P.,Indian Institute of Chemical Technology | Reddy Y.N.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2017

Using a one-pot Sharpless asymmetric epoxidation/regioselective epoxide ring-opening as a key step, the protecting-group-free total synthesis of goniothalesdiol A was accomplished in only three steps starting from commercially available trans-cinnamaldehyde in 55.1% overall yield. In 6 previously reported total syntheses, 6-11 steps were required. © 2017 Elsevier Ltd.


Satapathy S.,Indian Institute of Chemical Technology | Kothapalli R.V.S.,Indian Institute of Chemical Technology
Journal of Polymers and the Environment | Year: 2017

This study presents the preparation of Natural fiber-reinforced biocomposites based on Recycled High Density Polyethylene (RHDPE)/Banana Fiber (BF)/Fly ash Cenospheres (FACS) and aims to increase the economic value of these waste materials. Maleic anhydride grafted HDPE (MA-g-HDPE) was used as a compatibilizer to increase the dispersion of fibers into the polymer matrix as well as to increase the compatibility between the matrix and fillers. Variation in mechanical, thermal and dynamic mechanical properties with the addition of FACS in RHDPE/BF composites was investigated. It was observed that 7.5 wt% FACS, 30 wt% BF and 3 wt% MA-g-HDPE within RHDPE matrix resulted in an increase in tensile strength to 17%, tensile modulus to 188%, flexural strength to 38%, flexural modulus to 159% and hardness to 37% as compared with the RHDPE matrix. Significant enhancement in the thermal stability of the RHDPE/BF biocomposites was also observed in presence of FACS under thermogravimetric analysis. The morphology of the prepared biocomposites has been examined by using scanning electron microscopy. Dynamic mechanical analysis tests revealed an increase in storage and loss modulus of the biocomposite system. The use of such recycled material, agricultural and industrial wastes increased the properties of the final product suggesting their use to be a good alternative in the production of polymeric composites. © 2017 Springer Science+Business Media New York


Chilivery R.,Indian Institute of Chemical Technology | Rana R.K.,Indian Institute of Chemical Technology
ACS Applied Materials and Interfaces | Year: 2017

A polyamine-mediated bioinspired strategy to assemble Keggin-type phosphomolybdic acid (PMA) clusters is demonstrated for the fabrication of microcapsule (MC) structures with unique surface textures. It involves supramolecular aggregation of polyamines with multivalent anions, which then allows the assembly of negatively charged PMA into MCs in an aqueous medium under ambient conditions. Resembling the role of polyamines in biosilicification of diatoms, the polyamine-anion interaction is shown to be the key for the assembly process. It not only provides structural stability but also facilitates an interesting transition from a smooth to a wrinkled surface alongside a change in the Keggin form to its lacunary form depending on the pH of the medium. Moreover, the presence of isolated PMA units in the hybrid structure enables them to be active in catalyzing the aerobic oxidation of alkenes under solvent-free conditions with better selectivity and reusability. Hence, the assembly approach represents an effective way for heterogenization of PMA-based materials and is expected to find considerable application in the wider hybrid-cluster field. © 2016 American Chemical Society.


Dumpala M.,Indian Institute of Chemical Technology | Theegala S.,Indian Institute of Chemical Technology | Palakodety R.K.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2017

Herein we report the stereoselective total synthesis of first occurrence distaminolyne A via aminolytic kinetic resolution, Corey-Fuch's reaction for alkyne formation and Cardiot-Chodkiewicz cross coupling followed by Wittig olefination as the key steps. © 2017


Vamshi Krishna K.,Indian Institute of Chemical Technology | Venkata Mohan S.,Indian Institute of Chemical Technology
Bioresource technology | Year: 2016

This study is intended to examine the effect of pretreatment on selective enrichment of electrogenic bacteria from mixed culture. It has been observed that the iodopropane and heat-shock pretreatments suppress the growth of non-exoelectrons, while selecting only a limited number of strains belonging to genera Xanthomonas, Pseudomonas and Prevotella while untreated control inoculum showed more diverse community comprising of both exoelectrogens and non-exoelectrogens. High power output was observed in iodopropane (180mW/m(2)) pretreated microbial fuel cell (MFC) compared to heat-shock pretreated MFC (128mW/m(2)) and untreated control (92mW/m(2)). Coulombic efficiency of iodopropane and heat-shock pretreated MFC was higher compared to untreated control MFC, while drop in pH and volatile fatty acids (VFA) production was less in iodopropane pretreated MFC signifying the shifts in bacterial community structure toward electrogenesis instead of fermentation. These results signify the role of iodopropane and heat pretreatments on enrichment of electrogenic bacteria for fuel cell application. Copyright © 2016 Elsevier Ltd. All rights reserved.


Kundu S.,Indian Institute of Chemical Technology
Journal of Biomolecular Structure and Dynamics | Year: 2017

The hallmark of Parkinson’s disease (PD) is the intracellular protein aggregation forming Lewy Bodies (LB) and Lewy neuritis which comprise mostly of a protein, alpha synuclein (α-syn). Molecular dynamics (MD) simulation methods can augment experimental techniques to understand misfolding and aggregation pathways with atomistic resolution. The quality of MD simulations for proteins and peptides depends greatly on the accuracy of empirical force fields. The aim of this work is to investigate the effects of different force fields on the structural character of β hairpin fragment of α-syn (residues 35–56) peptide in aqueous solution. Six independent MD simulations are done in explicit solvent using, AMBER03, AMBER99SB, GROMOS96 43A1, GROMOS96 53A6, OPLS-AA, and CHARMM27 force fields with CMAP corrections. The performance of each force field is assessed from several structural parameters such as root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), solvent accessible surface area (SASA), formation of β-turn, the stability of folded β-hairpin structure, and the favourable conformations obtained for different force fields. In this study, CMAP correction of CHARMM27 force field is found to overestimate the helical conformation, while GROMOS96 53A6 is found to most successfully capture the conformational dynamics of α-syn β-hairpin fragment as elicited from NMR. © 2017 Informa UK Limited, trading as Taylor & Francis Group


Raji Reddy C.,Indian Institute of Chemical Technology | Dilipkumar U.,Indian Institute of Chemical Technology | Shravya R.,Indian Institute of Chemical Technology
Chemical Communications | Year: 2017

A novel one-pot benzannulation reaction has been developed for the synthesis of substituted polycyclic aromatic hydrocarbons (PAHs) from the direct coupling of propargylic aldehydes/alcohols with 1,1-diarylethanol through an atom-economical uninterrupted three/four-step reaction sequence under mild and metal-free reaction conditions. The strategy involves an acid-catalyzed dehydration and carbon-carbon bond formation followed by DBU-promoted cycloisomerization. Naphthalene and phenanthrene were obtained via mono-benzannulation, and chrysene, picene and benzopicene were obtained involving consecutive di-benzannulation reactions in good yields starting from easily accessible starting materials. © The Royal Society of Chemistry.


Harish B.,Indian Institute of Chemical Technology | Subbireddy M.,Indian Institute of Chemical Technology | Suresh S.,Indian Institute of Chemical Technology
Chemical Communications | Year: 2017

A novel organocatalytic approach, harnessing the unique reactivities of N-heterocyclic carbenes (NHCs), has been revealed for the construction of indoles. The NHC-catalysed atom economical synthesis of a wide range of 2-substituted indole-3-acetic acid derivatives is displayed. Strategic application of the developed method was demonstrated for a short synthesis of a cyclin-dependent kinase (CDK) inhibitor: paullone. © 2017 The Royal Society of Chemistry.


Sreedhar I.,BITS Pilani Hyderabad Campus | Nahar T.,BITS Pilani Hyderabad Campus | Venugopal A.,Indian Institute of Chemical Technology
Renewable and Sustainable Energy Reviews | Year: 2017

Global warming and associated climate change has resulted in serious efforts towards reducing greenhouse gas emissions, primarily carbon dioxide through carbon capture. There are various technical options in pre- and post-combustion modes available viz., adsorption, absorption, membrane separation, chemical looping combustion with and without oxygen uncoupling and cryogenic separations. Among all these, absorption technology which could be deployed as a post-combustion option to be integrated with power plant, has been commercialized with amines as solvents long back. But there is a long way to go to improve this process in terms of economic viability due to large regeneration costs involved and to make it more environmental friendly with minimum toxic and corrosion problems due to solvents. In this review, absorption based carbon capture has been reviewed comprehensively and critically in terms of various aspects like solvents and their synthesis protocols, performance analysis of different solvent systems, contactors, kinetics and thermodynamics, modeling and simulation studies etc. Every section has been discussed in terms of the trends and developments observed including the contemporary status besides citing future challenges and prospects to improve the technology. © 2017 Elsevier Ltd


Kumar R.N.,Indian Institute of Chemical Technology | Kumar N.S.,Indian Institute of Chemical Technology | Meshram H.M.,Indian Institute of Chemical Technology
Synlett | Year: 2017

A route towards the stereocontrolled synthesis of arthrobotrisin A based on a Nozaki–Hiyama–Kishi (NHK) coupling strategy was developed. Highlights of the fragment synthesis include enzyme-catalyzed kinetic resolution, Negishi carbometalation–iodination, quinone formation through oxidation with hypervalent iodine, chiral oxazaborolidine-catalyzed asymmetric Diels–Alder reaction with cyclopentadiene, regio- and stereoselective epoxidation, Noyori reduction, retro-Diels–Alder reaction, diastereoselective Luche reduction, and, finally, a Nozaki–Hiyama–Kishi (NHK) coupling of the vinyl iodide fragment. Copyright © 2017, Georg Thieme Verlag. All rights reserved.


Chauhan A.S.,Dendritic Nanotechnology Inc. | Jain N.K.,Dr Hari Singh Gour University | Diwan P.V.,Indian Institute of Chemical Technology
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2010

A toxicity study of different polyamidoamine (PAMAM) dendrimers in Swiss albino mice was performed with a clinical overview. In the current study, mice were treated with various G4 dendrimers (NH2 and OH surface groups) at different dosage levels (low, medium and high) via the intraperitoneal route for 15 consecutive days, followed by a 15 day recovery period. The toxicity profile was investigated in mice for their general behaviour, feed intake, body weight, carbohydrate, lipid and protein metabolism, haematological parameters, histopathology and cell viability. No significant differences were observed in feed intake, body weight and organ weight among the various dendrimer-fed groups and control. In general, dendrimers have no significant effect on the carbohydrate and lipid metabolism. However, declined glucose levels in the high-NH2 dose group indicates the interference of this dosage level with glucose metabolism. Although all the test groups showed activity in the normal range, the high-NH2 group showed comparatively higher alanine aminotransferase and aspartate aminotransferase activity. Minor, but insignificant (p <0.05), differences were observed in the red blood cells, haematocrit value and haemoglobin of the treated group when compared to the control group in a dose-dependent manner, but these recovered during the recovery period. There was no effect on other haematological parameters. Histopathological evaluation of dendrimer-treated groups did not reveal any abnormalities in the low- and medium-dose groups, but at a high dose level, toxicity was observed in the liver and kidney. However, after the recovery period, toxicity in the high dose level was not found. A cell viability study of cationic dendrimers has shown reduced cytotoxicity after the complexation with a guest molecule such as indomethacin. This study showed that dendrimers are not toxic, in general. The high dose of G4-NH2 displayed some toxicity; however, that too was recovered after some time. This journal is © 2009 The Royal Society.


Sahu B.D.,Indian Institute of Chemical Technology | Kuncha M.,Indian Institute of Chemical Technology | Sistla R.,Indian Institute of Chemical Technology
Phytomedicine | Year: 2013

Nephrotoxicity is an important complication in cancer patients undergoing cisplatin therapy. Oxidative stress, inflammation and apoptosis/necrosis are the major patho-mechanisms of cisplatin induced nephrotoxicity. In the present study, hesperidin, a naturally-occurring bioflavonoid has been demonstrated to have protective effect on cisplatin-induced renal injury in rats. Cisplatin intoxication resulted in structural and functional renal impairment which was revealed by massive histopathological changes and elevated blood urea nitrogen and serum creatinine levels, respectively. Renal injury was associated with oxidative stress/lipid peroxidation as evident by increased reactive oxygen species (ROS) and malondialdehyde (MDA) formation with decreased levels of antioxidants such as reduced glutathione, vitamin C, catalase, superoxide dismutase, glutathione reductase, glutathione peroxidase and glutathione-S-transferase. Cisplatin administration also triggered inflammatory response in rat kidneys by inducing pro-inflammatory cytokine, TNF-α, with the increased expression of myeloperoxidase (MPO). Furthermore, cisplatin increased the activity of caspase-3 and DNA damage with decreased tissue nitric oxide levels. Hesperidin treatment significantly attenuated the cisplatin-induced oxidative stress/lipid peroxidation, inflammation (infiltration of leukocytes and pro-inflammatory cytokine), apoptosis/necrosis (caspase-3 activity with DNA damage) as well as increased expression of nitric oxide in the kidney and improved renal function. Thus, our results suggest that hesperidin co-administration may serve as a novel and promising preventive strategy against cisplatin-induced nephrotoxicity. © 2012 Elsevier GmbH.


Mukherjee N.,Chittaranjan National Cancer Institute | Bhattacharya N.,Chittaranjan National Cancer Institute | Alam N.,Chittaranjan National Cancer Institute | Roychoudhury S.,Indian Institute of Chemical Technology | Panda C.K.,Chittaranjan National Cancer Institute
Cancer Science | Year: 2012

The aim of the study is to understand the importance of the Wnt/β-catenin pathway in the development of breast cancer (BC) and its association with different clinicopathological parameters. Alterations (deletion/methylation/expression) of some Wnt/β-catenin pathway antagonists like APC, SFRP1/2, CDH1 and activator β-catenin (CTNNB1) were analyzed in primary BC in Indian patients. High frequencies (65-70%) of overall alterations (deletion/methylation) of the antagonists were seen in the BC samples. Also, 99% (156/158) of the samples showed alterations in any one of the genes, indicating the importance of this pathway in the development of this tumor. Co-alterations of these genes were observed in 30% of samples, with significantly high alterations in late-onset (37%) and estrogen receptor (ER)-/progesterone receptor (PR)- (37%) BC compared with early onset (21%) and ER/PR+ (18%) BC samples, respectively. Significantly high (P-value= 0.001-0.02) alterations of APC and CDH1 genes were seen in ER-/PR- BC compared with ER/PR+ BC. Immunohistochemical analysis showed reduced expression of the Wnt antagonists in BC concordant with their molecular alterations. Nuclear localization of β-catenin showed significant association with alterations in the antagonists and was also significantly high in the ER-/PR- BC samples. Alterations of SFRP2 coupled with a late clinical stage and low/nulliparity predicted the worst prognosis in BC patients. Therefore, the present study suggests that cumulative alterations in more than one Wnt antagonist along with increased nuclear accumulation of β-catenin play an important role in the development of BC and have significant clinical as well as prognostic importance. © 2011 Japanese Cancer Association.


Agarwal M.,Indian Institute of Chemical Technology | Venkata Mohan S.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2015

A comprehensive study on the potential of pyrolysis of activated sludge to generate substances that can be used to produce energy was evaluated for its technical and environmental viability. The products of the process viz., pyrolysis gas, pyrolysis oil and char can readily be used by the major energy consumers viz., electricity and transportation. Based on the results obtained it is estimated that a 1. ton capacity process for pyrolysis of activated sludge can serve the electrical needs of a maximum of 239, 95 and 47 Indian houses per day, considering lower middle class, middle class and upper middle class, respectively. In addition the process would also produce the daily methane (CNG) requirement of 128 public transport buses. The process was determined to be technically feasible at low and medium temperatures for both, pyrolysis gas and electrical energy. The gas generated could be utilized as fuel directly while the oil generated would require pretreatment before its potential application. The process is potentially sustainable when commercialized and can self-sustain in continuous mode of operation in biorefinery context. © 2014 Elsevier Ltd.


Mishra A.K.,Indian Institute of Chemical Technology | Allauddin S.,Indian Institute of Chemical Technology | Narayan R.,Indian Institute of Chemical Technology | Raju K.V.S.N.,Indian Institute of Chemical Technology
Ceramics International | Year: 2012

Montmorillonite K-10 clay was surface-modified using the cationic surfactants viz., butyltriphenylphosphonium bromide (BTPB), cetyltrimethylammonium bromide (CTAB), and tributylhexadecylphosphonium (TBHPB) bromide. Of these, CTAB and TBHPB modified clays were chosen for surface grafting with 3-aminopropyltrimethoxy silane (APTMS) coupling agent. The nanocomposites were fully characterized by powder X-ray diffraction (XRD), solid state 29Si NMR, Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA). The XRD and FTIR confirmed the increase in basal plane spacing and intercalation of long chain surfactant molecules into the clay gallery, while TGA indicated the onset degradation and 10% weight loss temperature (T 10%) in case of quaternary phosphonium modified clay that was higher than the corresponding ammonium counterpart; these values increased further after the grafting with APTMS. The 29Si NMR peak deconvolution study suggested that the molar % of T units and total degree of silica condensation for different APTMS grafted clay samples were more than 20% and 80%, respectively. © 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.


Ghosh S.,Indian Institute of Chemical Technology | Chaganti S.R.,Indian Institute of Chemical Technology | Chaganti S.R.,University of Windsor | Prakasham R.S.,Indian Institute of Chemical Technology
Journal of Molecular Catalysis B: Enzymatic | Year: 2012

In this study, polyaniline nanofibers are used as a novel immobilization support and evaluated using l-asparaginase as a model protein enzyme for precise investigation of the immobilized state of enzymes as well as its functional activity on polyaniline nanofiber surfaces at different concentrations. The supported enzyme has been characterized by XPS, XRD, TEM and FTIR, and the effect of polymer nanofiber conformations on the enzymatic activity is discussed in detail. Immobilized l-asparaginase showed greater stability towards decomposition/denaturation at different temperatures and pH conditions compared to the free enzyme. The calculated Km values are 1.809 and 3.705 mM L-1 for immobilized l-asparaginase, respectively, which are 2.05-fold lower in magnitude in comparison with the value obtained for free l-asparaginase; the Vmax values for immobilized and free l-asparaginase are 90.57 and 48.04 μM min-1 mg-1 respectively.© 2011 Elsevier B.V. All rights reserved.


Bhowmick S.,Dr Kanailal Bhattacharyya College | Ravindran R.,Emory Vaccine Center | Ali N.,Indian Institute of Chemical Technology
BMC Microbiology | Year: 2014

Background: Visceral leishmaniasis caused by the protozoan parasite Leishmania donovani complex is a potentially fatal disease if left untreated. Few treatment options exist and are toxic, costly and ineffective against resistant strains. Thus a safe and efficacious vaccine to combat this disease is needed. Previously, we reported that intraperitoneal administration of leishmanial antigens (LAg) entrapped in liposomes conferred protection to BALB/c mice against L. donovani challenge infection. However, this vaccine failed to protect mice when administered subcutaneously. We therefore evaluated whether formulation of LAg in combination with two commonly used human-compatible adjuvants, alum and saponin, could improve the protective efficacy of subcutaneously administered LAg, to a level comparable to that of the intraperitoneal liposomal vaccination. Results: Vaccine formulations of LAg with alum or saponin failed to reduce parasite burden in the liver, and alum + LAg immunized mice also failed to reduce parasite burden in the spleen. Interestingly, saponin + LAg vaccination actually resulted in an increased L. donovani parasitic load in the spleen following L. donovani challenge, suggesting this regimen exacerbates the infection. In contrast, mice immunized intraperitoneally with Lip + LAg demonstrated significant protection in both liver and spleen, as expected. Mechanistically, we found that failure of alum + LAg to protect mice was associated with elevated levels of IL-4, whereas both IL-4 and IL-10 levels were increased in saponin + LAg immunized mice. This outcome served to exacerbate L. donovani infection in the saponin + LAg group, despite a concurrent increase in proinflammatory IFN-γ production. On the contrary, protection against L. donovani challenge in Lip + LAg immunized mice was associated with elevated levels of IFN-γ in conjunction with low levels of IL-4 and IL-10 production. Conclusions: These findings indicate that elevated levels of IL-4 may contribute to LAg vaccine failure, whereas combined elevation of IL-4 together with IL-10 exacerbated the disease as observed in saponin + LAg immunized mice. In contrast, a robust IFN-γ response, in the absence of IL-4 and IL-10 production, was associated with protective immunity following administration of the Lip + LAg vaccine. Together these findings suggest that optimization of antigen/adjuvant formulations to minimize IL-4 and IL-10 induction may be helpful in the development of high efficacy vaccines targeting Leishmania. © 2014 Bhowmick et al.; licensee BioMed Central Ltd.


Agarwal M.,Indian Institute of Chemical Technology | Mohan S.V.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2013

Pyrolysis of kitchen based vegetable waste (KVW) was studied in a designed packed bed reactor. The effect of process parameters like temperature, time and catalyst on bio-gas yield and its composition was studied. The total bio-gas yield was found to be maximum with non-catalysed operation (260ml/g) at 1073K (180min). Higher hydrogen (H2) yield with non-catalysed operation (32.68%) was observed at 1073K (180min) while with catalysed operation the requisite temperature (873K) and time (120min) reduced with both silica gel (33.34%) and sand (41.82%) thus, saving energy input. Methane (CH4) yield was found to be highest (4.44times than non-catalysed and 1.42 with silica gel) in presence of sand (71.485ml/g) at medium temperature (873K) and time (60min). The catalyst operation reduced the carbondioxide (CO2) share from 47.29% to 41.30% (silica gel catalysed) and 21.91% (sand catalysed) at 873K. © 2012 Elsevier Ltd.


Agrawal S.,CNR Institute of Molecular Science and Technologies | Pastore M.,CNR Institute of Molecular Science and Technologies | Marotta G.,CNR Institute of Molecular Science and Technologies | Reddy M.A.,Indian Institute of Chemical Technology | And 2 more authors.
Journal of Physical Chemistry C | Year: 2013

Combining computational modeling and experimental optical analyses, we investigate two prototypical phenothiazine-based organic solar cell sensitizers with the aim to understand the individual effects of solvation and aggregation on the dyes optical properties. Dye solvation and aggregation play a crucial role in determining the photoelectrochemical properties of these systems and the interplay of these two factors can lead to a misinterpretation of the underlying phenomenology due to their similar spectroscopic signals. In particular, upon adsorption of the dye onto the metal oxide surface, the dye UV-vis absorption spectrum may attain either a blue or a red shift compared to the dye in solution, which can either be originated from aggregation of surface-adsorbed dye and solvatochromism in the initial dye solution. Understanding the origin of these spectral changes along with their possible effect on charge-transfer properties is important for the further improvement of dye-sensitized solar cells. Based on our results, we show that the optical properties of phenothiazine-based dyes are much more sensitive to the type of explicit interactions with the solvent than to aggregation on the TiO 2 surface. Therefore, this study gets new insights into the understanding of these properties and may assist the molecular engineering of new and more efficient dyes sensitizers. © 2013 American Chemical Society.


Reddy B.R.,Indian Institute of Chemical Technology | Raju B.,Indian Institute of Chemical Technology | Lee J.Y.,Korea Institute of Geoscience and Mineral Resources | Park H.K.,Korea Institute of Geoscience and Mineral Resources
Journal of Hazardous Materials | Year: 2010

Spent catalysts from automobile industry contain environmentally critical and economically valuable metals such as Pt, Pd, Fe, Ni, Mn, and Cr. In this paper, we present a process for the selective separation and complete recovery of palladium (Pd) and platinum (Pt) from hydrochloric acid leach liquors of spent automobile catalyst employing solvent extraction method. Typical composition of leach liquor used for the present study contains (mg/L): Pd-150, Pt-550, Mn-500, Ni-1000, Fe-1500, Cr-100 and 3. M HCl. Selective separation of Pd from the leach liquor is achieved with 0.5. vol.% LIX 84I (2-hydroxy-5-nonylacetophenone oxime in a mixture with a high flash point hydrocarbon diluent) in kerosene at an aqueous to organic (A/O) ratio of 3 in 2 stages, with an enrichment factor of three. Quantitative stripping of Pd from loaded organic is achieved with 0.5. M thiourea and 1. M HCl. Co-extraction of Fe and Pt with 5. vol.% Alamine 336 (tertiary amine of mixed tri-octyl/decyl amine) in kerosene followed by selective scrubbing of Fe with dilute HCl and complete stripping of Pt from loaded organic was proposed with 0.5. M thiourea and 0.1. M HCl. Purity of Pd and Pt strip solutions are 99.7%. Finally, the present process can solve environmental related issues and at the same time recover valuable metals in pure form. © 2010 Elsevier B.V.


Venishetty V.K.,Texas Tech University Health Sciences Center | Venishetty V.K.,Indian Institute of Chemical Technology | Komuravelli R.,Kakatiya University | Kuncha M.,Indian Institute of Chemical Technology | And 2 more authors.
Nanomedicine: Nanotechnology, Biology, and Medicine | Year: 2013

Docetaxel is used in the treatment of many types of cancer, but its entry into the brain is restricted by p-glycoprotein (p-gp) efflux. A potential drug-drug interaction exists between docetaxel and ketoconazole because both agents are metabolized hepatically by the cytochrome P-450 system, and ketoconazole can inhibit p-gp efflux of docetaxel at blood brain barrier. Hence, these two drugs were loaded in solid lipid nanoparticles (SLNPs) and surface of these NPs were modified with folic acid for brain targeting. These NPs were characterized for particle size, zeta potential, entrapment efficiency, in vitro drug release, cytotoxicity, and cell uptake in brain endothelial cell lines. Plasma and brain pharmacokinetics have shown increased brain uptake of docetaxel with surface-modified dual drug-loaded SLNPs. Brain permeation coefficient (Kin) of folate-grafted docetaxel and ketoconazole loaded SLNPs was 44 times higher than that of Taxotere. Hence, these NPs were suitable for the delivery of lipophilic anticancer drugs to the brain. From the Clinical Editor: In this paper, successful delivery of docetaxel and ketoconazole is reported using solid lipid nanoparticles surface modified with folic acid for brain targeting, which may pave the way to optimized clinical applications of lipophilic anticancer drugs to the brain. © 2013 Elsevier Inc.


Dey A.K.,Indian Institute of Chemical Technology | Bhagat A.,Indian Institute of Chemical Technology | Bhagat A.,Australian Council for Educational Research India | Chowdhury R.,Indian Institute of Chemical Technology
Journal of Bacteriology | Year: 2013

Vibrio cholerae, a noninvasive bacterium, colonizes the intestinal epithelium and secretes cholera toxin (CT), a potent enterotoxin that causes the severe fluid loss characteristic of the disease cholera. In this study, we demonstrate that adherence of V. cholerae to the intestinal epithelial cell line INT 407 strongly induces the expression of the major virulence genes ctxAB and tcpA and the virulence regulatory gene toxT. No induction of toxR and tcpP, which encode transcriptional activators of toxT, was observed in adhered bacteria, and the adherence-dependent upregulation of toxT expression was independent of ToxR and TcpP. A sharp increase in the expression of the vieA gene, which encodes a cyclic di-GMP (c-di-GMP) phosphodiesterase, was observed in INT 407-adhered V. cholerae immediately after infection. Induction of toxT, ctxAB, and tcpA in INT 407-adhered vieA mutant strain O395 δvieA was consistently lower than in the parent strain, although no effect was observed in unadhered bacteria, suggesting that VieA has a role in the upregulation of toxT expression specifically in host cell-adhered V. cholerae. Furthermore, though VieA has both a DNA binding helix-turn-helix domain and an EAL domain conferring c-di-GMP phosphodiesterase activity, the c-di-GMP phosphodiesterase activity of VieA is necessary and sufficient for the upregulation of toxT expression. © 2013, American Society for Microbiology.


Arjmand F.,Aligarh Muslim University | Jamsheera A.,Aligarh Muslim University | Mohapatra D.K.,Indian Institute of Chemical Technology
Journal of Photochemistry and Photobiology B: Biology | Year: 2013

Novel dipeptide complexes Cu(II)ṡVal-Pro (1), Zn(II)ṡVal-Pro (2), Cu(II)ṡAla-Pro (3) and Zn(II)ṡAla-Pro (4) were synthesized and thoroughly characterized using different spectroscopic techniques including elemental analyses, IR, NMR, ESI-MS and molar conductance measurements. The solution stability study carried out by UV-vis absorption titration over a broad range of pH proved the stability of the complexes in solution. In vitro DNA binding studies of complexes 1-4 carried out employing absorption, fluorescence, circular dichroism and viscometric studies revealed the binding of complexes to DNA via groove binding. UV-vis titrations of 1-4 with mononucleotides of interest viz., 5′-GMP and 5′-TMP were also carried out. The DNA cleavage activity of the complexes 1 and 2 were ascertained by gel electrophoresis assay which revealed that the complexes are good DNA cleavage agents and the cleavage mechanism involved a hydrolytic pathway. Furthermore, in vitro antitumor activity of complex 1 was screened against human cancer cell lines of different histological origin. © 2013 Elsevier B.V. All rights reserved.


Parveen S.,Aligarh Muslim University | Arjmand F.,Aligarh Muslim University | Mohapatra D.K.,Indian Institute of Chemical Technology
Journal of Photochemistry and Photobiology B: Biology | Year: 2013

Dipeptide (Pro-Gly and Pro-Leu) Zinc(II) complexes 1 and 2 were designed and synthesized for potential use as cancer chemotherapeutic agents. In order to augment the DNA recognition of metallonuclease activity, zinc metal ion was tethered to peptide motif to carry out DNA site specific hydrolytic cleavage. The structural formulation of the complexes 1 and 2 was done by elemental analysis, spectroscopic methods (IR, NMR, electronic) and molar conductance measurements. Their in vitro DNA binding profile was investigated by UV-vis titrations, fluorescence titrations and circular dichroism which revealed that these complexes bind to CT DNA by electrostatic interactions via groove binding mode. Zn(II) Pro-Gly complex 1 showed greater binding affinity to CT DNA as compared to the Zn(II) Pro-Leu complex 2 due to steric constraints in the latter. The supercoiled pBR322 DNA cleavage activity of complex 1, ascertained by gel electrophoresis demonstrated efficient DNA cleaving ability via hydrolytic mechanistic pathway. Further, the molecular docking studies confirmed that complex 1 bind to the minor groove of DNA having AT-rich sequences with relative binding energy of -196.72 kJ mol-1. © 2013 Elsevier B.V. All rights reserved.


Higashibayashi S.,Graduate University for Advanced Studies | Onogi S.,Graduate University for Advanced Studies | Srivastava H.K.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

Throwing a curve: The first example of a through-bond stereoelectronic effect for curved aromatic compounds is described for buckybowls, that is, benzylic-substituted sumanenes. Methyl- and hydroxysumanene favor the endo-R conformer because of a difference in the strength, between the conformers, of the hyperconjugation of the benzylic C-H bond with the bowl. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Numata Y.,Japan National Institute of Materials Science | Singh S.P.,Indian Institute of Chemical Technology | Islam A.,Japan National Institute of Materials Science | Iwamura M.,University of Toyama | And 4 more authors.
Advanced Functional Materials | Year: 2013

A novel Ru π-expanded terpyridyl sensitizer, referred to as HIS-2, is prepared based on the molecular design strategy of substitution with a moderately electron-donating 4-methylstyryl group onto the terpyridyl ligand. The HIS-2 dye exhibits a slightly increased metal-to-ligand charge transfer (MLCT) absorption at around 600 nm and an intense π-π* absorption in the UV region compared with a black dye. Density functional theory calculations reveal that the lowest unoccupied molecular orbital (LUMO) is distributed over the terpyridine and 4-methylstyryl moieties, which enhances the light-harvesting capability and is appropriate for smooth electron injection from the dye to the TiO2 conduction band. The incident photon-to-electricity conversion efficiency spectrum of HIS-2 exhibits better photoresponse compared with black dye over the whole spectral region as a result of the extended π-conjugation. A DSC device based on black dye gives a short-circuit current (JSC) of 21.28 mA cm-2, open-circuit voltage (VOC) of 0.69 V, and fill factor (FF) of 0.72, in an overall conversion efficiency (η) of 10.5%. In contrast, an HIS-2 based cell gives a higher JSC value of 23.07 mA cm-2 with VOC of 0.68 V, and FF of 0.71, and owing to the higher JSC value of HIS-2, an improved η value of 11.1% is achieved. Moderate electron-donating substituents are important for enhancement of the light harvesting capability of Ru(II) sensitizers. Substitution of a terpyridyl ligand with a 4-methylstyryl group increases the molecular absorption coefficient from the UV to the NIR region compared with black dye owing to the wider lowest unoccupied molecular orbital (LUMO) distributed over the terpyridyl and extended π-conjugation. The intense absorption gives a high JSC of 23.07 mA cm-2, and a resulting overall conversion efficiency of 11.1%. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Arjmand F.,Aligarh Muslim University | Parveen S.,Aligarh Muslim University | Mohapatra D.K.,Indian Institute of Chemical Technology
Inorganica Chimica Acta | Year: 2012

New Cu(II) and Zn(II)-based peptide solid complexes 1-4 were designed by de novo synthetic strategy from tetrapeptide ligands, Pro-Gly-Pro-Gly, L 1/Pro-Leu-Pro-Leu, L 2 and thoroughly characterized by various spectroscopic techniques. To confirm the stability of peptide complexes in solution, solution stability studies of 1 and 3 over a pH range 2-12 were carried out which revealed no change in absorption or intensity of bands. In vitro DNA binding studies employing various optical techniques were carried out to examine the propensity of complexes towards CT DNA. The results of corroborative experiments reveal that the complexes avidly bind to CT DNA via groove binding, with highest K b values for 1 indicative of strong binding propensity as compared to ligands and 2-4. To compare the binding affinity for nucleotides, UV-Vis titrations of 1 and 2 with 5′-GMP and 5′-TMP were carried out; further validated by 1H and 31P NMR. The supercoiled pBR322 DNA nuclease activity 1 and 2, demonstrated that both the complexes were capable of cleaving DNA but with striking differences in their nuclease activity; Cu(II) complex cleaved DNA through oxidative cleavage while Zn(II) complex followed hydrolytic cleavage pathway. © 2012 Elsevier B.V. All rights reserved.


Hellen E.H.,University of North Carolina at Greensboro | Volkov E.,RAS Lebedev Physical Institute | Kurths J.,Potsdam Institute for Climate Impact Research | Dana S.K.,Indian Institute of Chemical Technology
PLoS ONE | Year: 2011

An electronic analog of a synthetic genetic network known as the repressilator is proposed. The repressilator is a synthetic biological clock consisting of a cyclic inhibitory network of three negative regulatory genes which produces oscillations in the expressed protein concentrations. Compared to previous circuit analogs of the repressilator, the circuit here takes into account more accurately the kinetics of gene expression, inhibition, and protein degradation. A good agreement between circuit measurements and numerical prediction is observed. The circuit allows for easy control of the kinetic parameters thereby aiding investigations of large varieties of potential dynamics. © 2011 Hellen et al.


Ghosh A.,Indian Institute of Chemical Technology | Ghosh A.,Bose Institute of India | Sarkar S.,Indian Institute of Chemical Technology | Mandal A.K.,Indian Institute of Chemical Technology | Das N.,Indian Institute of Chemical Technology
PLoS ONE | Year: 2013

Cerebral stroke is the leading cause of death and permanent disability among elderly people. In both humans and animals, cerebral ischemia damages the nerve cells in vulnerable regions of the brain, viz., hippocampus, cerebral cortex, cerebellum, and hypothalamus. The present study was conducted to evaluate the therapeutic efficacy of nanoencapsulated quercetin (QC) in combating ischemia-reperfusion-induced neuronal damage in young and aged Swiss Albino rats. Cerebral ischemia was induced by occlusion of the common carotid arteries of both young and aged rats followed by reperfusion. Nanoencapsulated quercetin (2.7 mg/kg b wt) was administered to both groups of animals via oral gavage two hours prior to ischemic insults as well as post-operation till day 3. Cerebral ischemia and 30 min consecutive reperfusion caused a substantial increase in lipid peroxidation, decreased antioxidant enzyme activities and tissue osmolality in different brain regions of both groups of animals. It also decreased mitochondrial membrane microviscosity and increased reactive oxygen species (ROS) generation in different brain regions of young and aged rats. Among the brain regions studied, the hippocampus appeared to be the worst affected region showing increased upregulation of iNOS and caspase-3 activity with decreased neuronal count in the CA1 and CA3 subfields of both young and aged rats. Furthermore, three days of continuous reperfusion after ischemia caused massive damage to neuronal cells. However, it was observed that oral treatment of nanoencapsulated quercetin (2.7 mg/kg b wt) resulted in downregulation of iNOS and caspase-3 activities and improved neuronal count in the hippocampal subfields even 3 days after reperfusion. Moreover, the nanoformulation imparted a significant level of protection in the antioxidant status in different brain regions, thus contributing to a better understanding of the given pathophysiological processes causing ischemic neuronal damage. © 2013 Ghosh et al.


Sharma S.,Lv Prasad Eye Institute | Das S.,Lv Prasad Eye Institute | Joseph J.,Indian Institute of Chemical Technology | Vemuganti G.K.,Lv Prasad Eye Institute | Murthy S.,Lv Prasad Eye Institute
Survey of Ophthalmology | Year: 2011

Since the devastation of the European silk worm industry in the 19th century, microsporidia have been recognized as important organisms. An enormous literature is available on their biology, phylogeny, classification, disease profile, diagnosis, and treatment; however, it is only recently that ophthalmologists have begun to take note of these organisms. The last two decades have seen several publications related to ocular microsporidiosis, in particular those forms affecting the cornea. Both immunocompetent and immunocompromised patients are at risk of developing corneal infections that may range from self limiting mild keratoconjunctivitis to severe stromal keratitis recalcitrant to medical treatment. Exposure to soil, muddy water, and minor trauma are possible risk factors. Although reliable prevalence data are lacking, recent studies indicate a high prevalence of microsporidial keratoconjunctivitis in the rainy season, especially in India and other countries with similar climates. For instance, a high prevalence has been documented in Singapore. We bring together the information available on ocular microsporidiosis. © 2011 Elsevier Inc.


Schroder K.,Leibniz Institute for Catalysis at the University of Rostock | Join B.,Leibniz Institute for Catalysis at the University of Rostock | Amali A.J.,Leibniz Institute for Catalysis at the University of Rostock | Amali A.J.,Indian Institute of Chemical Technology | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2011

It's no sacrifice: A bio-inspired iron system, in which a β-keto ester serves as a sacrificial cosubstrate, readily epoxidizes olefins under ambient conditions with air. Aromatic olefins are oxidized in high yields with excellent chemoselectivity. Mechanistic investigations point out substantial differences to well-known radical-based autoxidations. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Manna D.,Bose Institute of India | Dutta P.K.,Indian Institute of Chemical Technology | Achari B.,Indian Institute of Chemical Technology | Lohia A.,Bose Institute of India
Antimicrobial Agents and Chemotherapy | Year: 2010

Oxalis corniculata is a naturally occurring weed that has been used in traditional medicine for the cure of dysentery and diarrhea in India. One of the common causes of dysentery is due to infection by the protist pathogen Entamoeba histolytica. Bioactivity profiling of extracts from O. corniculata identified several compounds that showed antiamoebic activity in axenic cultures of E. histolytica. These were characterized by nuclear magnetic resonance, infrared, and mass spectrometry as (i) Oc-1, a mixture of saturated fatty acids C24 to C28; (ii) Oc-2, a mixture of long-chain alcohols C18 to C28; and (iii) Oc-3, a single compound that was a galacto-glycerolipid (GGL). Of the different compounds that were obtained, the strongest antiamoebic activity was found in GGL. The addition of GGL to E. histolytica xenic cultures containing other microbial flora from the large intestine did not affect its antiamoebic activity. Amoebicidal concentrations of GGL had no effect on intestinal microbial flora or on the mammalian cell line HEK-293. GGL was also found to be equally effective in killing another protist pathogen, Giardia lamblia, that causes diarrhea in humans. The importance of this study is based on the identification of novel natural products and the possibility of developing these compounds as active agents to treat at least two pathogenic parasitic intestinal infections endemic to tropical regions. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Mukhopadhyay A.,Indian Central Glass and Ceramic Research Institute | Joshi N.,Indian Institute of Chemical Technology | Chattopadhyay K.,Indian Institute of Chemical Technology | De G.,Indian Central Glass and Ceramic Research Institute
ACS Applied Materials and Interfaces | Year: 2012

We report here a facile and green synthetic approach to prepare magnetite (Fe 3O 4) nanoparticles (NPs) with magnetic core and polyethylene glycol (PEG) surface coating. The interaction of the bare and PEG-coated Fe 3O 4 NPs with cytochrome c (cyt c, an important protein with direct role in the electron transfer chain) is also reported in this study. With ultrasonication as the only peptization method and water as the synthesis medium, this method is easy, fast, and environmentally benign. The PEG coated NPs are highly water dispersible and stable. The bare NPs have considerable magnetism at room temperature; surface modification by PEG has resulted in softening the magnetization. This approach can very well be applicable to prepare biocompatible, surface-modified soft magnetic materials, which may offer enormous utility in the field of biomedical research. Detailed characterizations including XRD, FTIR, TG/DTA, TEM, and VSM of the PEG-coated Fe 3O 4 NPs were carried out in order to ensure the future applicability of this method. Although the interaction of bare NPs with cyt c shows reduction of the protein, efficient surface modification by PEG prevents its reduction. © 2011 American Chemical Society.


Nancharaiah Y.V.,Bhabha Atomic Research Center | Nancharaiah Y.V.,UNESCO-IHE Institute for Water Education | Venkata Mohan S.,Indian Institute of Chemical Technology | Lens P.N.L.,UNESCO-IHE Institute for Water Education | Lens P.N.L.,Tampere University of Technology
Bioresource Technology | Year: 2015

Metal laden wastes and contamination pose a threat to ecosystem well being and human health. Metal containing waste streams are also a valuable resource for recovery of precious and scarce elements. Although biological methods are inexpensive and effective for treating metal wastewaters and in situ bioremediation of metal(loid) contamination, little progress has been made towards metal(loid) recovery. Bioelectrochemical systems are emerging as a new technology platform for removal and recovery of metal ions from metallurgical wastes, process streams and wastewaters. Biodegradation of organic matter by electroactive biofilms at the anode has been successfully coupled to cathodic reduction of metal ions. Until now, leaching of Co(II) from LiCoO2 particles, and removal of metal ions i.e. Co(III/II), Cr(VI), Cu(II), Hg(II), Ag(I), Se(IV), and Cd(II) from aqueous solutions has been demonstrated. This article reviews the state of art research of bioelectrochemical systems for removal and recovery of metal(loid) ions and pertaining removal mechanisms. © 2015 Elsevier Ltd. All rights reserved.


Sharma S.,Pohang University of Science and Technology | Maurya R.A.,Pohang University of Science and Technology | Maurya R.A.,Indian Institute of Chemical Technology | Min K.-I.,Pohang University of Science and Technology | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2013

Can't smell this: An integrated continuous-flow microfluidic setup enables in situ generation, extraction, separation, and reaction of foul-smelling isocyanides with little exposure to the surroundings. Isocyanides were generated by dehydration of the corresponding N-substituted formamides, and several representative isocyanide-based organic reactions were successfully performed. DIPEA=N,N-diisopropylethylamine. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Basavaraju K.C.,Pohang University of Science and Technology | Sharma S.,Pohang University of Science and Technology | Maurya R.A.,Indian Institute of Chemical Technology | Kim D.-P.,Pohang University of Science and Technology
Angewandte Chemie - International Edition | Year: 2013

Putting osmium in its place: The immobilization of hazardous OsO 4 on polymer nanobrushes in a microreactor is a safe, effective, and green concept. The method allows reactions to be performed in a time- and chemical-saving manner, with little environmental impact, as compared to spill-over bulk processes. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Kalivendi S.V.,Indian Institute of Chemical Technology | Yedlapudi D.,Indian Institute of Chemical Technology | Hillard C.J.,Medical College of Wisconsin | Kalyanaraman B.,Medical College of Wisconsin
Free Radical Biology and Medicine | Year: 2010

α-Synuclein (α-syn) is a presynaptic protein that is widely implicated in the pathophysiology of Parkinson's disease (PD). Emerging evidence indicates a strong correlation between α-syn aggregation and proteasomal dysfunction as one of the major pathways responsible for destruction of the dopamine neurons. Using parkinsonism mimetics (MPP+, rotenone) and related oxidants, we have identified an oxidant-induced alternative splicing of α-syn mRNA, generating a shorter isoform of α-syn with deleted exon-5 (112-syn). This spliced isoform has an altered localization and profoundly inhibits proteasomal function. The generation of 112-syn was suppressed by constitutively active MEK-1 and enhanced by inhibition of the Erk-MAP kinase pathway. Overexpression of 112-syn exacerbated cell death in a human dopaminergic cell line compared to full-length protein. Expression of 112-syn and proteasomal dysfunction were also evident in the substantia nigra and to a lesser extent in striatum, but not in the cortex of MPTP-treated mice. We conclude that oxidant-induced alternative splicing of α-syn plays a crucial role in the mechanism of dopamine neuron cell death and thus contributes to PD. © 2009.


Maurya R.A.,Indian Institute of Chemical Technology | Min K.-I.,Pohang University of Science and Technology | Kim D.-P.,Pohang University of Science and Technology
Green Chemistry | Year: 2014

An integrated microfluidic system for multiple reactions and separations of hazardous ethyl diazoacetate is presented. The integrated techniques include: a droplet technique for liquid-liquid and/or gas-liquid separation and in situ generation of the toxic reagent, a dual channel membrane technique based on a cheap polymeric microseparator for liquid-liquid separation, and a capillary microreactor for carrying out cascade reactions in a sequential and continuous manner. © 2014 The Royal Society of Chemistry.


Sengupta J.,New York State Department of Health | Sengupta J.,Indian Institute of Chemical Technology | Bussiere C.,University of Texas at Austin | Pallesen J.,Howard Hughes Medical Institute | And 5 more authors.
Journal of Cell Biology | Year: 2010

The nucleocytoplasmic shuttling protein Nmd3 is an adaptor for export of the 60S ribosomal subunit from the nucleus. Nmd3 binds to nascent 60S subunits in the nucleus and recruits the export receptor Crm1 to facilitate passage through the nuclear pore complex. In this study, we present a cryoelectron microscopy (cryo-EM) reconstruction of the 60S subunit in complex with Nmd3 from Saccharomyces cerevisiae. The density corresponding to Nmd3 is directly visible in the cryo-EM map and is attached to the regions around helices 38, 69, and 95 of the 25S ribosomal RNA (rRNA), the helix 95 region being adjacent to the protein Rpl10. We identify the intersubunit side of the large subunit as the binding site for Nmd3. rRNA protection experiments corroborate the structural data. Furthermore, Nmd3 binding to 60S subunits is blocked in 80S ribosomes, which is consistent with the assigned binding site on the subunit joining face. This cryo-EM map is a first step toward a molecular understanding of the functional role and release mechanism of Nmd3. © 2010 Sengupta et al.


Nancharaiah Y.V.,Bhabha Atomic Research Center | Nancharaiah Y.V.,UNESCO-IHE Institute for Water Education | Venkata Mohan S.,Indian Institute of Chemical Technology | Lens P.N.L.,Tampere University of Technology
Bioresource Technology | Year: 2015

Metal laden wastes and contamination pose a threat to ecosystem well being and human health. Metal containing waste streams are also a valuable resource for recovery of precious and scarce elements. Although biological methods are inexpensive and effective for treating metal wastewaters and in situ bioremediation of metal(loid) contamination, little progress has been made towards metal(loid) recovery. Bioelectrochemical systems are emerging as a new technology platform for removal and recovery of metal ions from metallurgical wastes, process streams and wastewaters. Biodegradation of organic matter by electroactive biofilms at the anode has been successfully coupled to cathodic reduction of metal ions. Until now, leaching of Co(II) from LiCoO2 particles, and removal of metal ions i.e. Co(III/II), Cr(VI), Cu(II), Hg(II), Ag(I), Se(IV), and Cd(II) from aqueous solutions has been demonstrated. This article reviews the state of art research of bioelectrochemical systems for removal and recovery of metal(loid) ions and pertaining removal mechanisms. © 2015 Elsevier Ltd.


Venkata Mohan S.,Indian Institute of Chemical Technology | Suresh Babu P.,Indian Institute of Chemical Technology | Naresh K.,Indian Institute of Chemical Technology | Velvizhi G.,Indian Institute of Chemical Technology | Madamwar D.,Sardar Patel University
Bioresource Technology | Year: 2012

Functional behavior of anoxic-aerobic-anoxic microenvironment on azo dye (C.I. Acid black 10B) degradation was evaluated in a periodic discontinuous batch mode operation for 26 cycles. Dye removal efficiency and azo-reductase activity (30.50 ± 1. U) increased with each feeding event until 13th cycle and further stabilized. Dehydrogenase activity also increased gradually and stabilized (2.0 ± 0.2 μg/ml) indicating the stable proton shuttling between metabolic intermediates providing higher number of reducing equivalents towards dye degradation. Voltammetric profiles showed drop in redox catalytic currents during stabilized phase also supports the consumption of reducing equivalents towards dye removal. Change in Tafel slopes, polarization resistance and other bioprocess parameters correlated well with the observed dye removal and biocatalyst behavior. Microbial community analysis documented the involvement of specific organism pertaining to aerobic and facultative functions with heterotrophic and autotrophic metabolism. Integrating anoxic microenvironment with aerobic operation might have facilitated effective dye mineralization due to the possibility of combining redox functions. © 2012 Elsevier Ltd.


Potumarthi R.,Indian Institute of Chemical Technology | Potumarthi R.,Monash University | Baadhe R.R.,Indian Institute of Chemical Technology | Jetty A.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2012

Pretreatment of biomass for bioethanol production makes it necessary to use large amounts of water for removing inhibitors and neutralization. In order to reduce water usage, separate batches of corncobs were hydrolyzed in 1M NaOH and 0.05M H2SO4, respectively, and the hydrolysis products were mixed to achieve a pH of 7. This approach lowered water usage by 10-fold compared with neutralization by distilled and recycling wash water. Mixing of the pretreated biomasses (121°C, 20min) increased release of reducing sugars during enzymatic hydrolysis with cellulases (38.49 FPU(IU)) produced by Phanerochaete chrysosporium NCIM 1106 by 2- and 15-fold compared with the sugars released from the unmixed NaOH- and H2SO4-treated corncobs, respectively. Enzymatic hydrolysis (EH, cell free extract) of the mixed material released 395.15mg/ml of sugars during 48h, slightly less than what was achieved by microbial hydrolysis (whole cell hydrolysis), 424.50mg after 120h. © 2012 Elsevier Ltd.


Potumarthi R.,Indian Institute of Chemical Technology | Potumarthi R.,Monash University | Baadhe R.R.,Indian Institute of Chemical Technology | Nayak P.,Indian Institute of Chemical Technology | Jetty A.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2013

Phanerochete chrysosporium, the white-rot fungus, (a best source for lignolytic enzymes system) was used in the biological pretreatment of rice husk for reducing sugars production. Usually reducing sugar production through biochemical process involves two steps: solid state fermentation (SSF) of fungal pretreatment for delignification, subsequently pretreated biomass subjected to enzymatic hydrolysis. During the fungal pretreatment of rice husk for reducing sugar production along with cellulase and xylanse, the activities of lignin degradation-related enzymes such as lignin peroxidases (LiP), GLOX (glyoxidase), and aryl alcohol oxidases (AAO), were observed. The fungal pretreated rice husk produced highest (895.9. mg/ml/2. g of rise husk) reducing sugars on 18th day of fungal treatment. This method may be good alternative to avoid operational costs associated with washing and the removal of inhibitors during the conventional pretreatment methods. © 2012 Elsevier Ltd.


Nancharaiah Y.V.,Bhabha Atomic Research Center | Nancharaiah Y.V.,UNESCO-IHE Institute for Water Education | Mohan S.V.,Indian Institute of Chemical Technology | Lens P.N.L.,UNESCO-IHE Institute for Water Education | Lens P.N.L.,Tampere University of Technology
Trends in Biotechnology | Year: 2016

Metal-bearing solid and liquid wastes are increasingly considered as secondary sources of critical and scarce metals. Undoubtedly, microorganisms are a cost-effective resource for extracting and concentrating diffuse elements from secondary sources. Microbial biotechnology for extracting base metals from ores and treatment of metal-laden wastewaters has already been applied at full scale. By contrast, microbe-metal interactions in the recovery of scarce metals and a few critical metals have received attention, whereas the recovery of many others has been barely explored. Therefore, this article explores and details the potential application of microbial biotechnologies in the recovery of critical and scarce metals. In the past decade bioelectrochemical systems have emerged as a new technology platform for metal recovery coupled to the removal of organic matter. Overview of potential applications of microorganisms in critical metal recovery.Engineering of microbe-metal interactions for recovering rare earth elements and platinum group metals.Reductive mineral dissolution is a new dimension to biomining.Bioelectrochemical systems offer a new technology platform in metal recovery. © 2015 Elsevier Ltd.


Nandre K.P.,Indian Institute of Chemical Technology | Bhosale S.V.,RMIT University | Rama Krishna K.V.S.,Indian Institute of Chemical Technology | Gupta A.,Monash University | Bhosale S.V.,Indian Institute of Chemical Technology
Chemical Communications | Year: 2013

A naphthalene diimide motif bearing phosphonic acid functionalities has been found to be self-assembled with l- and d-arginine through chirality induced molecular recognitions and leads to the formation of micrometre long nanobelts and spherical aggregates at pH 9 in water, respectively. © 2013 The Royal Society of Chemistry.


News Article | September 7, 2016
Site: phys.org

As health departments around the U.S. boost efforts to combat Zika, scientists are working on new ways to kill the mosquitoes that carry the virus. One approach involves understanding the molecular mechanisms that keep the bugs alive so we can then undermine them. Scientists report in the ACS journal Biochemistry that they have revealed new structural insights on a key protein from Aedes aegypti, the mosquito species most often linked to the spread of Zika. In February, the World Health Organization called for action against the disease after Brazil experienced a spike in the number of babies born with microcephaly, a condition characterized by an abnormally small head. Since then, the virus has been reported in more than 40 countries. Studies have shown that compounds that inhibit a protein called sterol carrier protein 2 (SCP2), which is involved in the transport of cholesterol and fats in insects, can kill Aedes aegypti larva. Kiran K. Singarapu and colleagues from CSIR - Indian Institute of Chemical Technology wanted to take a closer look at the structure of one of the protein's variants to help inform the development of future insecticides. Using solution nuclear magnetic resonance, a technique that yields molecular-level information about proteins, the researchers were able to describe the 3-D structure and dynamics of a SCP2 variant. The new insights could help scientists screen small-molecule libraries for insecticide candidates. In addition to curbing Zika, any resulting compound that stamps out Aedes aegypti could reduce cases of other illnesses—dengue fever, yellow fever and chikungunya—that the mosquito also carries. More information: Kiran Kumar Singarapu et al. Solution Nuclear Magnetic Resonance Studies of Sterol Carrier Protein 2 Like 2 (SCP2L2) Reveal the Insecticide Specific Structural Characteristics of SCP2 Proteins inMosquitoes, Biochemistry (2016). DOI: 10.1021/acs.biochem.6b00322 Abstract Sterol carrier protein 2 like 2 from Aedes aegypti (AeSCP2L2) plays an important role in lipid transport in mosquitoes for its routine metabolic processes. Repeated unsuccessful attempts to crystallize ligand free SCP2L2 prompted us to undertake nuclear magnetic resonance (NMR) spectroscopy to determine its three-dimensional structure. We report here the three-dimensional structures and dynamics of apo-AeSCP2L2 and its complex with palmitate. The 15N heteronuclear single-quantum coherence spectrum of apo-AeSCP2L2 displayed multiple peaks for some of the amide resonances, implying the presence of multiple conformations in solution, which are transformed to a single conformation upon formation of the complex with plamitate. The three-dimensional structures of apo-AeSCP2L2 and palmitated AeSCP2L2 reveal an α/β mixed fold, with five β-strands and four α-helices, very similar to the other SCP2 protein structures. Unlike the crystal structure of palmitated AeSCP2L2, both solution structures are monomeric. It is further confirmed by the rotational correlation times determined by NMR relaxation times (T1 and T2) of the amide protons. In addition, the palmitated AeSCP2L2 structure contains two palmitate ligands, bound in the binding pocket, unlike the three palmitates bound in the dimeric form of AeSCP2L2 in the crystals. The relaxation experiments revealed that complex formation significantly reduces the dynamics of the protein in solution.


Sen T.,Indian Association for The Cultivation of Science | Mandal S.,Indian Association for The Cultivation of Science | Haldar S.,Indian Institute of Chemical Technology | Chattopadhyay K.,Indian Institute of Chemical Technology | Patra A.,Indian Association for The Cultivation of Science
Journal of Physical Chemistry C | Year: 2011

Here, we study the human serum albumin (HSA) protein-Au nanoparticle interaction to identify the specific binding site of protein with nanoparticles by using the surface energy transfer (SET) method among tryptophan (Trp) of HSA, ANS-dye-labeled HSA protein, and Au nanoparticles. Here, ANS dye is used as a probe located at domain IIIA of HSA. In particular, absorbance, fluorescence quenching, decay time, circular dichroism, dynamic light scattering, and TEM measurements are performed to understand the physical properties of protein-conjugated Au nanoparticles. Using the SET method, the measured distances between the Trp residue of HSA and the binding site of HSA interacting with Au nanoparticles are 42.5, 41.9, and 48.1 Å for 1.5, 2.0, and 2.9 nm HSA-conjugated Au nanoparticles, respectively. The measured distances between the binding site of ANS dye (located at domain IIIA) in HSA to the binding site of HSA interacting with Au nanoparticles are 51, 51.5, and 54.7 Å for 1.5, 2.0, and 2.9 nm HSA-conjugated Au nanoparticles, respectively. From the protein structural data (using PyMol software), the distances from the center of domain IIIA to Cys53-Cys62 disulfide bond and Trp to Cys53-Cys62 disulfide bond are obtained to be 51.5 and 39.1 Å, respectively. Thus, the distances calculated by using SET equation (Trp to Au binding site distance and ANS to Au binding site distance) nicely match with the distances obtained from protein structural data by using PyMol software. Analysis suggests that the Au nanoparticle is attached to HSA by linkage through Cys53-Cys62 disulfide bond which is located at subdomain IA of HSA. © 2011 American Chemical Society.


Sabitha G.,Indian Institute of Chemical Technology | Rao A.S.,Indian Institute of Chemical Technology | Yadav J.S.,Indian Institute of Chemical Technology | Yadav J.S.,KingSaud University
Tetrahedron Asymmetry | Year: 2011

The stereoselective synthesis of (-)-synparvolide B, isolated from Syncolostemon parviflorus, has been accomplished from (S)-ethyl lactate. A 1,2-chelation controlled allylation, Sharpless asymmetric epoxidation, Brown asymmetric allylation and RCM reactions were used as the key steps. © 2011 Elsevier Ltd. All rights reserved.


Rudra D.S.,Indian Institute of Science | Pal U.,Indian Institute of Chemical Technology | Maiti N.C.,Indian Institute of Chemical Technology | Reiter R.J.,University of Texas Health Science Center at San Antonio | Swarnakar S.,Indian Institute of Science
Journal of Pineal Research | Year: 2013

The zinc-dependent matrix metalloproteinases (MMPs) are key enzymes associated with extracellular matrix (ECM) remodeling; they play critical roles under both physiological and pathological conditions. MMP-9 activity is linked to many pathological processes, including rheumatoid arthritis, atherosclerosis, gastric ulcer, tumor growth, and cancer metastasis. Specific inhibition of MMP-9 activity may be a promising target for therapy for diseases characterized by dysregulated ECM turnover. Potent MMP-9 inhibitors including an indole scaffold were recently reported in an X-ray crystallographic study. Herein, we addressed whether melatonin, a secretory product of pineal gland, has an inhibitory effect on MMP-9 function. Gelatin zymographic analysis showed a significant reduction in pro- and active MMP-9 activity in vitro in a dose- and time-dependent manner. In addition, a human gastric adenocarcinoma cell line (AGS) exhibited a reduced (~50%) MMP-9 expression when incubated with melatonin, supporting an inhibitory effect of melatonin on MMP-9. Atomic-level interaction between melatonin and MMP-9 was probed with computational chemistry tools. Melatonin docked into the active site cleft of MMP-9 and interacted with key catalytic site residues including the three histidines that form the coordination complex with the catalytic zinc as well as proline 421 and alanine 191. We hypothesize that under physiological conditions, tight binding of melatonin in the active site might be involved in reducing the catalytic activity of MMP-9. This finding could provide a novel approach to physical docking of biomolecules to the catalytic site of MMPs, which inhibits this protease, to arrest MMP-9-mediated inflammatory signals. © 2012 John Wiley & Sons A/S.


Kar S.,Indian Institute of Chemical Technology | Ukil A.,University of Calcutta | Sharma G.,Indian Institute of Chemical Technology | Das P.K.,Indian Institute of Chemical Technology
Journal of Leukocyte Biology | Year: 2010

The role of phosphatases in the impairment of MAPK signaling, which is directly responsible for Leishmania-induced macrophage dysfunction, is still poorly understood. Gene expression profiling revealed that Leishmania donovani infection markedly up-regulated the expression of three phosphatases: MKP1, MKP3, and PP2A. Inhibition of these phosphatases prior to infection points toward preferential induction of the Th2 response through deactivation of p38 by MKP1. On the other hand, MKP3 and PP2A might play significant roles in the inhibition of iNOS expression through deactivation of ERK1/2. Among various PKC isoforms, PKCζ was associated with induction of MKP3 and PP2A in infected macrophages, whereas PKCε was correlated with MKP1 induction. Inhibition of phosphatases in L. donovani-infected BALB/c mice shifted the cytokine balance in favor of the host by inducing TNF-α and iNOS expression. This was validated by cystatin, an immunomodulator and curing agent for experimental visceral leishmaniasis, which showed that inhibition of MKPs and PP2A activity may be necessary for a favorable T cell response and suppression of organ parasite burden. This study, for the first time, suggests the possibility of the involvement of MAPK-directed phosphatases in the establishment of L. donovani infection. © Society for Leukocyte Biology.


Swarnakar S.,Indian Institute of Chemical Technology | Paul S.,Indian Institute of Chemical Technology | Singh L.P.,Indian Institute of Chemical Technology | Reiter R.J.,University of Texas Health Science Center at San Antonio
Journal of Pineal Research | Year: 2011

Matrix metalloproteinases (MMPs) are part of a superfamily of metal-requiring proteases that play important roles in tissue remodeling by breaking down proteins in the extracellular matrix that provides structural support for cells. The intricate balance in protease/anti-protease stoichiometry is a contributing factor in a number of diseases. Melatonin possesses multifunctional bioactivities including antioxidative, anti-inflammatory, endocrinologic and behavioral effects. As melatonin affects the redox status of tissues, the association of reactive oxygen species (ROS) with tissue injury under different circumstances may be mitigated by melatonin. Redox signaling is expanding into all areas of basic and clinical sciences, and this timely review focuses on the topic of regulation of MMP activities by melatonin. This is a rapidly growing field. Accumulating evidence indicates that oxidative stress plays an important role in regulating the activities of MMPs that are involved in various cellular processes such as cellular proliferation, angiogenesis, apoptosis, invasion and metastasis. This review offers sections on MMPs, melatonin, major physiological and pathophysiological conditions in the context to MMPs, followed by redox signaling mechanisms that are known to influence the cellular processes. Finally, we discuss the emerging molecular mechanisms relevant to regulatory actions of melatonin on the activities of MMPs. The possibility that melatonin might have therapeutic significance via regulation of MMPs may be a novel approach in the treatment of some diseases. © 2010 John Wiley & Sons A/S.


Naskar J.,Indian Association for The Cultivation of Science | Roy S.,Indian Association for The Cultivation of Science | Joardar A.,Indian Institute of Chemical Technology | Das S.,Indian Institute of Chemical Technology | Banerjee A.,Indian Association for The Cultivation of Science
Organic and Biomolecular Chemistry | Year: 2011

Self-assembling short peptides can offer an opportunity to make useful nano-/microstructures that find potential application in drug delivery. We report here the formation of multivesicular structures from self-assembling water-soluble synthetic amphiphilic dipeptides containing a glutamic acid residue at the C-terminus. These vesicular structures are stable over a wide range of pH (pH 2-12). However, they are sensitive towards calcium ions. This causes the rupturing of these vesicles. Interestingly, these vesicles can not only encapsulate an anticancer drug and a fluorescent dye, but also can release them in the presence of calcium ions. Moreover, these multivesicular structures have the potential to carry biologically important molecules like cyclic adenosine monophosphate (cAMP) within the cells keeping their biological functions intact. A MTT cell-survival assay suggests the almost nontoxic nature of these vesicles. Thus, these peptide vesicles can be used as biocompatible delivery vehicles for carrying drugs and other bioactive molecules. © 2011 The Royal Society of Chemistry.


Dey R.,Indian Association for The Cultivation of Science | Sreedhar B.,Indian Institute of Chemical Technology | Ranu B.C.,Indian Association for The Cultivation of Science
Tetrahedron | Year: 2010

Palladium(II) chloride supported on 4 Å molecular sieves efficiently catalyzes the Suzuki coupling reactions of chlorobenzenes in presence of tetrabutylammonium bromide without any ligand. The useful intermediates for the synthesis of bioactive compounds such as irbesartan, and losartan have been prepared in one step following this reaction. The preparation of this catalyst is very simple. The FE-SEM image shows a cube shape ordered structure. The catalyst does not exhibit any nanoparticles as indicated by TEM. EDS and XPS demonstrate anchoring of Pd on molecular sieves in +2 oxidation state. This heterogeneous catalyst is stable, non-air sensitive and recyclable. © 2010 Elsevier Ltd. All rights reserved.


Manna J.,Nanomaterials Laboratory | Begum G.,Nanomaterials Laboratory | Kumar K.P.,Indian Institute of Chemical Technology | Misra S.,Indian Institute of Chemical Technology | Rana R.K.,Nanomaterials Laboratory
ACS Applied Materials and Interfaces | Year: 2013

Herein, we present an environmentally benign method capable of mineralization and deposition of nanomaterials to introduce antibacterial functionalities into cotton fabrics under mild conditions. Similar to the way in which many naturally occurring biominerals evolve around the living organism under ambient conditions, this technique enables flexible substrates like the cotton fabric to be coated with inorganic-based functional materials. Specifically, our strategy involves the use of long-chain polyamines known to be responsible in certain biomineralization processes, to nucleate, organize, and deposit nanostructured ZnO on cotton bandage in an aqueous solution under mild conditions of room temperature and neutral pH. The ZnO-coated cotton bandages as characterized by SEM, confocal micro-Raman spectroscopy, XRD, UV-DRS, and fluorescence microscopy demonstrate the importance of polyamine in generating a stable and uniform coating of spindle-shaped ZnO particles on individual threads of the fabric. As the coating process requires only mild conditions, it avoids any adverse effect on the thermal and mechanical properties of the substrate. Furthermore, the ZnO particles on cotton fabric show efficient antibacterial activity against both gram-positive and gram-negetive bacteria. Therefore, the developed polyamine mediated bioinspired coating method provides not only a facile and "green" synthesis for coating on flexible substrate but also the fabrication of antibacterial enabled materials for healthcare applications. © 2013 American Chemical Society.


Praveen Kumar D.,Yogi Vemana University | Shankar M.V.,Yogi Vemana University | Mamatha Kumari M.,Yogi Vemana University | Sadanandam G.,Indian Institute of Chemical Technology | And 2 more authors.
Chemical Communications | Year: 2013

Solar light induced interfacial charge transfer of electrons from TiO 2 to CuO in a water-glycerol mixture produced 99823 μmol h -1 g-1 catalyst of hydrogen gas. The dispersed CuO/TiO2 photocatalyst in solution exhibited uni-directional electron flow and capture at the Schottky barrier facilitating charge separation and electron transfer resulting in enhanced H2 production performance. © 2013 The Royal Society of Chemistry.


Pradhan S.,Indian Institute of Chemical Technology | Mallick S.K.,University of Calcutta | Chowdhury R.,Indian Institute of Chemical Technology
PLoS ONE | Year: 2013

A unique event in bacterial epidemiology was the emergence of the El Tor biotype of Vibrio cholerae O1 and the subsequent rapid displacement of the existing classical biotype as the predominant cause of epidemic cholera. We demonstrate that when the El Tor and classical biotypes were cocultured in standard laboratory medium a precipitous decline in colony forming units (CFU) of the classical biotype occurred in a contact dependent manner. Several lines of evidence including DNA release, microscopy and flow cytometric analysis indicated that the drastic reduction in CFU of the classical biotype in cocultures was not accompanied by lysis, although when the classical biotype was grown individually in monocultures, lysis of the cells occurred concomitant with decrease in CFU starting from late stationary phase. Furthermore, uptake of a membrane potential sensitive dye and protection of genomic DNA from extracellular DNase strongly suggested that the classical biotype cells in cocultures retained viability in spite of loss of culturability. These results suggest that coculturing the classical biotype with the El Tor biotype protects the former from lysis allowing the cells to remain viable in spite of the loss of culturability. The stationary phase sigma factor RpoS may have a role in the loss of culturability of the classical biotype in cocultures. Although competitive exclusion of closely related strains has been reported for several bacterial species, conversion of the target bacterial population to the viable non-culturable state has not been demonstrated previously and may have important implications in the evolution of bacterial strains. © 2013 Pradhan et al.


Choudhury R.,Kalyani University | Choudhury R.,University of Witwatersrand | Das P.,Kalyani University | De T.,Indian Institute of Chemical Technology | Chakraborti T.,Kalyani University
Immunobiology | Year: 2013

Visceral leishmaniasis caused by the intracellular parasite Leishmania donovani is a major public health problem in the developing world. The emergence of increasing number of L. donovani strains resistance to antimonial drugs recommended worldwide requires the intervention of effective vaccine strategy for treatment of VL. In the present study L. donovani culture derived, soluble, secretory serine protease (pSP) has been shown to be vaccine target of VL. Protection from VL could be achieved by the use of safer vaccine which generally requires an adjuvant for induction of strong Th1 response. To assess the safety, immunogenicity and efficacy of pSP as vaccine candidate in mouse model we used IL-12 as adjuvant. BALB/c mice immunized with pSP+IL-12 were protected significantly from challenged infection even after four months by reducing the parasite load in liver and spleen and suppressed the development of the disease along with an increase in IgG2a antibody level in serum, enhanced delayed type hypersensitivity and strong T-cell proliferation. Groups receiving pSP+IL-12 had an augmented pSP antigen specific Th1 cytokines like IFN-γ and TNF-α response with concomitant decrease of Th2 cytokines IL-4 and IL-10 after vaccination. In this study the vaccine efficacy of pSP was further assessed for its prophylactic potential by enumerating matrix metalloprotease-9 (MMP-9) profile which has been implicated in various diseases. MMP-9 associated with different microbial infections is controlled by their natural inhibitors (TIMPS) and by some cytokines. In this study pSP was found to regulate excessive inflammation by modulating the balance between MMP-9 and TIMP-1 expression. This modulatory effect has also been demonstrated by IFN-γ mediated down regulation of TNF-α induced MMP-9 expression in activated murine macrophages. This is the first report where a secretory L. donovani serine protease (pSP) adjuvanted with IL-12 could also act as protective imunogen by modifying cytokine mediated MMP-9 expression in experimental VL. These findings elucidate the mechanisms of regulation of MMP-9 following infection of L. donovani in vaccinated animals and thus pave the way for developing new immunotherapeutic interventions for VL. © 2012 Elsevier GmbH.


Modak A.,Indian Association for The Cultivation of Science | Barui A.K.,Indian Institute of Chemical Technology | Ranjan Patra C.,Indian Institute of Chemical Technology | Bhaumik A.,Indian Association for The Cultivation of Science
Chemical Communications | Year: 2013

A novel hybrid nanoporous material (LNH-1) bearing a tris(propyliminomethyl)-phloroglucinol fluorescent moiety in the framework has been designed and administration of an LNH-1 based drug delivery system containing doxorubicin to cancer cells showed inhibition of proliferation, suggesting its future potential theranostics application in cancer. This journal is © The Royal Society of Chemistry.


Kuhbeck D.,University of Regensburg | Saidulu G.,Indian Institute of Chemical Technology | Reddy K.R.,Indian Institute of Chemical Technology | Diaz D.D.,University of Regensburg | Diaz D.D.,University of Zaragoza
Green Chemistry | Year: 2012

The effectiveness of neutral pH chitosan hydrogel beads (CSHB) as a green organocatalyst for a variety of C-C bond forming reactions (i.e. aldol reaction, Knoevenagel condensation, nitroaldol (Henry) reaction, Michael addition) has been comprehensively evaluated. Reaction rates, conversions and selectivities were studied as a function of a series of input variables including size, pH and reactive surface area of the beads, catalyst loading, temperature, molecular weight of the biopolymer, concentration, solvent system and molar ratio of reactants. Moreover, the catalytic biohydrogel beads were characterized by a variety of techniques including, among others, SEM, FT-IR, TGA and DSC. © 2012 The Royal Society of Chemistry.


Sabitha G.,Indian Institute of Chemical Technology | Reddy S.S.S.,Indian Institute of Chemical Technology | Yadav J.S.,Indian Institute of Chemical Technology | Yadav J.S.,KingSaud University
Tetrahedron Letters | Year: 2011

The first total synthesis of cryptopyranmoscatone A1 isolated from Cryptocarya moschata has been accomplished from 3,4,6-tri-O-acetyl-d-glucal. In addition to the RCM and cross-metathesis (CM) reactions, the synthesis features a highly diastereoselective Brown's allylation reaction and sets the absolute stereochemistry of the natural product. © 2011 Elsevier Ltd. All rights reserved.


Bhattacharjee P.,Indian Institute of Chemical Technology | Chatterjee D.,Indian Institute of Chemical Technology | Singh K.K.,University of Alabama at Birmingham | Giri A.K.,Indian Institute of Chemical Technology
International Journal of Hygiene and Environmental Health | Year: 2013

Long term exposure to arsenic, either through groundwater, food stuff or occupational sources, results in a plethora of dermatological and non-dermatological health effects including multi-organ cancer and early mortality. Several epidemiological studies, across the globe have reported arsenic-induced health effects and cancerous outcomes; but the prevalence of such diseases varies depending on environmental factors (geographical location, exposure level), and genetic makeup (and variants thereof); which is further modulated by several other factors like ethnicity, age-sex, smoking status, diet, etc. It is also interesting to note that, chronic arsenic exposure to a similar extent, even among the same family members, result in wide inter-individual variations. To understand the adverse effect of this toxic metabolite on biological system (cellular targets), and to unravel the underlying molecular basis (at the level of transcript, proteome, or metabolite), a holistic, systems biology approach was taken. Due to the paradoxical nature and unavailability of any suitable animal model system; the literature review is primarily based on cell line and population based studies. Thus, here we present a comprehensive review on the systems biology approaches to explore the underlying mechanism of arsenic-induced carcinogenicity, along with our own observations and an overview of mitigation strategies and their effectiveness till date. © 2013 Elsevier GmbH.


Sadanandam G.,Indian Institute of Chemical Technology | Lalitha K.,Indian Institute of Chemical Technology | Kumari V.D.,Indian Institute of Chemical Technology | Shankar M.V.,Yogi Vemana University | Subrahmanyam M.,Indian Institute of Chemical Technology
International Journal of Hydrogen Energy | Year: 2013

Glycerol is the main by-product during the trans-esterification of vegetable oils to biodiesel. In this study, we investigate the process of photocatalytic hydrogen production from glycerol aqueous solution, with the use of cobalt doped TiO2 photocatalyst under solar light irradiation. Cobalt doped TiO2 photocatalysts are prepared by impregnation method and these catalysts are characterized by XRD, EDAX, DRS, TEM, EPR and XPS techniques. DRS studies clearly show the expanded photo response of TiO 2 into visible region on impregnation of Co2+ ions on surface of TiO2. XPS studies also show change in the binding energy values of O1s, Ti 2p and Co 2p, indicating that Co2+ ions are in interaction with TiO2. Maximum hydrogen production of 220 μ mol h-1 g-1 is observed on 2 wt% cobalt doped TiO2 catalysts in pure water under solar irradiation. A significant improvement in hydrogen production is observed in glycerol: water mixtures; and maximum hydrogen production of 11,021 μ mol h-1 g-1 is obtained over 1 wt% cobalt doped TiO2 in 5% glycerol aqueous solutions. Furthermore, to evaluate some reaction parameters such as cobalt wt% on TiO 2, glycerol concentration, substrate effect (alcohols) and pH of the solution on the hydrogen production activity are systematically investigated. When the catalysts are examined under UV irradiation, a 3-4 fold increase in activity is observed where this activity seems to decrease with time; however, a continuous activity is observed under solar irradiation on these catalysts. The decreased activity could be ascribed the loss of cobalt ions under UV irradiation, as evidenced by EDAX and TEM analysis. A possible explanation for the stable and continuous activity of cobalt doped TiO2 photocatalysts under solar irradiation is proposed. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Bhattacharyya S.,Indian Association for The Cultivation of Science | Prashanthi S.,Indian Institute of Chemical Technology | Bangal P.R.,Indian Institute of Chemical Technology | Patra A.,Indian Association for The Cultivation of Science
Journal of Physical Chemistry C | Year: 2013

Fluorescent dye encapsulated conjugated polymer nanoparticles have been paid significant attention for potential applications in photonics and biophotonics due to their high brightness and better photostability. Bright, photostable, and monodispersed Nile Red (NR) dye encapsulated poly-N-vinylcarbazole (PVK) fluorescent polymer nanoparticles have been prepared to understand the influence of size of particles and the concentration of dye inside the particles on the photophysical properties by using steady-state, time-resolved fluorescence spectroscopy and fluorescence correlation spectroscopy (FCS). Here, we have quantitatively analyzed the hydrodynamic diameter, particle brightness, and population of NR molecules inside the particle with varying the particle size and NR concentration by using fluorescence correlation spectroscopy (FCS). The average fluorescence intensity of a single nanoparticle, i.e., per particle brightness (PPB) value, increases from 80 to 500 kHz, and the number of NR molecules per nanoparticle increases from 5 to 22 by increasing the concentration of NR from 0.5 to 1.8 wt % at the time of nanoparticle preparation. Fluorescence anisotropy study has been undertaken to understand the rotational dynamics of encapsulated NR molecules with varying particle size and NR concentration inside the nanoparticle. The particle brightness and quantum yield are enhanced due to increasing the radiative decay rate. Higher brightness (almost one order of magnitude higher with respect to free dye) and better photostability (15-fold enhancement) of these polymer nanoparticles are found to be efficient for bioimaging purposes. © 2013 American Chemical Society.


Kundu D.,Indian Association for The Cultivation of Science | Bhadra S.,Indian Association for The Cultivation of Science | Mukherjee N.,Indian Association for The Cultivation of Science | Sreedhar B.,Indian Institute of Chemical Technology | Ranu B.C.,Indian Association for The Cultivation of Science
Chemistry - A European Journal | Year: 2013

A selective N-arylation of cyclic amides and amines in DMF and water, respectively, catalysed by CuII/Al2O3 has been achieved. This protocol has been employed for the synthesis of a library of arenes bearing a cyclic amide and an amine moiety at two ends, including a few scaffolds of therapeutic importance. The mechanism has been established based on detailed electron paramagnetic resonance (EPR) spectroscopy, X-ray photoelectron spectroscopy (XPS), UV diffuse reflectance spectroscopy (DRS) and inductively coupled plasma-mass spectrometry (ICP-MS) studies of the catalyst at different stages of the reaction. The CuII/Al2O 3 catalyst was recovered and recycled for subsequent reactions. One over the other: A selective N-arylation of cyclic amides and amines in DMF and water, respectively, catalyzed by CuII/Al2O3 has been achieved (see scheme). This protocol has been employed for the synthesis of a library of arenes bearing cyclic amide and amine moieties at two ends including a few scaffolds of therapeutic importance. The mechanism has been established based on detailed spectroscopic studies (FG=functional group). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Haldar S.,University of Calcutta | Roy Choudhury S.,Indian Institute of Chemical Technology | Sengupta S.,University of Calcutta
Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology | Year: 2011

Bioinoculants are environmentally friendly, energy efficient and economically viable resources in sustainable agriculture. Knowledge of the structure and activities of microbial population in the rhizosphere of a plant is essential to formulate an effective bioinoculant. In this study, the bacterial community present in the rhizosphere of an important oilseed legume, Arachis hypogaea (L.) was described with respect to adjoining bulk soil as a baseline control using a 16S rDNA based metagenomic approach. Significantly higher abundance of Gamma-proteobacteria, a prevalence of Bacillus and the Cytophaga-Flavobacteria group of Bacteroidetes and absence of the Rhizobiaceae family of Alpha-proteobacteria were the major features observed in the matured Arachis-rhizosphere. The functional characterization of the rhizosphere- competent bacteria was performed using culture-dependent determination of phenotypes. Most bacterial isolates from the groundnut-rhizosphere exhibited multiple biochemical activities associated with plant growth and disease control. Validation of the beneficial traits in candidate bioinoculants in pot-cultures and field trials is necessary before their targeted application in the groundnut production system. © 2011 Springer Science+Business Media B.V.


Mac D.H.,CNRS Chemistry Institute of Rennes | Mac D.H.,Hanoi University of Science | Chandrasekhar S.,Indian Institute of Chemical Technology | Gree R.,CNRS Chemistry Institute of Rennes
European Journal of Organic Chemistry | Year: 2012

This review reports on the total synthesis of gabosines, a family of secondary metabolites containing trihydroxylated cyclohexanone or cyclohexenone cores. Analysis of the different stategies used to prepare these natural products and their stereoisomers has been carried out with special attention paid to the methods employed for the formation of the carbocyclic ring. The different methods are compared in a table, and a discussion of future directions of research in this area is presented. Gabosines are a family of bioactive secondary metabolites from various Streptomyces strains. Total syntheses of carbasugars of this family reported to date are described. Key aspects include control of the absolute configurations at the stereocentres, generally achieved by use of appropriate chiral optically active starting materials, and methods used for elaboration of the carbocycles. © 2012 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sharma G.D.,R and nter for Engineering and Science | Singh S.P.,Indian Institute of Chemical Technology | Kurchania R.,Maulana Azad National Institute of Technology | Ball R.J.,University of Bath
RSC Advances | Year: 2013

A stepwise approach has been applied for the cosensitization of a thiocyanate free Ru sensitizer (SPS-01) with a metal free dye containing thienylfluorene conjugation (JD1) for dye sensitized solar cells (DSSCs). The cosensitized SPS-01 + JD1 based DSSC showed a significant enhancement in both the open circuit voltage (Voc) and the short circuit current (J sc) relative to the individual single dye based DSSCs. The DSSC based on the SPS-01 + JD1 system yielded a Jsc of 15.38 mA cm -2, a Voc of 0.72 V, a fill factor (FF) of 0.76 and a power conversion efficiency (PCE) of 8.30%. This performance was superior to that of the DSSCs sensitized with the individual dyes SPS-01 (PCE = 5.98%) or JD1 (PCE = 4.76%) fabricated under the same conditions. Results show that the JD1 dye effectively overcomes the competitive light absorption by I 3 -/I- and also prevents dye aggregation and reduces the charge recombination. To understand the effects of the charge recombination of the injected electrons with I3 - in the electrolyte, the dark current-voltage characteristics and electrochemical impedance spectra of the DSSCs sensitized with the SPS-01 and SPS-01+JD1 systems were measured. It was observed that the recombination of the electrons in the conduction band with I3 - in the electrolyte in the DSSC sensitized with SPS-01 +JD1 was significantly reduced relative to the DSSC based on SPS-01. © 2013 The Royal Society of Chemistry.


Sharma G.D.,R and nter for Engineering and Science | Singh S.P.,Indian Institute of Chemical Technology | Roy M.S.,Defence Laboratory | Mikroyannidis J.A.,University of Patras
Organic Electronics: physics, materials, applications | Year: 2012

The improvement of near infrared wavelength sensitivity in the bulk heterojunction organic polymer solar cell based on poly (3-hexylthiophene) (P3HT) and PC 70BM, by the addition of soluble DPP-CN small molecule is reported. By incorporating DPP-CN, the photosensitivity in the longer wavelength region was improved and the power conversion efficiency (PCE) has been reached to 4.37% as compared to 3.23% for the device based on P3HT:PC 70BM blend. The increase in the PCE is attributed to the increase in light harvesting property of the blend and efficient dissociation of excitons into free charge carriers due to the increased number of D-A sites. The PCE has been further enhanced to 4.70%, when mixed solvent cast P3HT:DPP-CN:PC 70BM blend is used as photoactive layer. The optical absorption spectra of the blend showed that the blend film cast from mixed solvent broadened the absorption wavelength range. This occurred as result of a large red shift of P3HT absorption peak and same time a widening and small red shift of DPP-CN absorption peak in the blend film. The improved light harvesting property of thermally annealed film is considered to the factor responsible for the improvement in the PCE. © 2012 Elsevier B.V. All rights reserved.


Sharma G.D.,University of Rajasthan | Sharma G.D.,R and nter for Science and Engineering | Mikroyannidis J.A.,University of Patras | Singh S.P.,Indian Institute of Chemical Technology
Organic Electronics: physics, materials, applications | Year: 2012

Two novel copolymers P1 and P2 having phenylenevinylene donor and cyanovinylene 4-nitrophenyl acceptor units, were synthesized by heck coupling and employed as electron donor along with PCBM or modified PCBM (F) as electron acceptor for the fabrication of bulk heterojunction (BHJ) photovoltaic devices. These copolymers P1 and P2 showed broad band absorption around 640-700 nm and optical band gap of 1.60 eV and 1.72 eV, respectively. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) estimated from cyclic voltammetry measurement reveals that these values are well suitable for the use of these copolymers as electron donor along with PCBM derivatives as electron acceptor for BHJ active layer. The suitable LUMO off set allows efficient photo-induced charge transfer at the donor/acceptor interfaces in the BHJ photovoltaic device and resulting power conversion efficiency (PCE) of 2.8% and 3.29% for P1 and P2, respectively, when PCBM is used as acceptor. This value has been improved up to 3.52% and 4.36% for the devices based on P1 and P2 when F is used as electron acceptor, instead of PCBM. We have also investigated the effect of solvent annealing on the photovoltaic performance of device based on P1: F and P2: F blends and found that the over all PCE of the devices is 4.36% and 4.88%, respectively. The increase in PCE is mainly due to the improvement in the J sc, which is due to the increased charge transport in the annealed device as compared to as cast device. © 2011 Elsevier B.V. All rights reserved.


Kumar D.,Max-Planck-Institut für Kohlenforschung | Kumar D.,Indian Institute of Chemical Technology | Thiel W.,Max-Planck-Institut für Kohlenforschung | De Visser S.P.,University of Manchester
Journal of the American Chemical Society | Year: 2011

Cysteine dioxygenase (CDO) is a vital enzyme for human health involved in the biodegradation of toxic cysteine and thereby regulation of the cysteine concentration in the body. The enzyme belongs to the group of nonheme iron dioxygenases and utilizes molecular oxygen to transfer two oxygen atoms to cysteinate to form cysteine sulfinic acid products. The mechanism for this reaction is currently disputed, with crystallographic studies implicating a persulfenate intermediate in the catalytic cycle. To resolve the dispute we have performed quantum mechanics/molecular mechanics (QM/MM) calculations on substrate activation by CDO enzymes using an enzyme monomer and a large QM active region. We find a stepwise mechanism, whereby the distal oxygen atom of the iron(II)-superoxo complex attacks the sulfur atom of cysteinate to form a ring structure, followed by dioxygen bond breaking and the formation of a sulfoxide bound to an iron(IV)-oxo complex. A sulfoxide rotation precedes the second oxygen atom transfer to the substrate to give cysteine sulfinic acid products. The reaction takes place on several low-lying spin-state surfaces via multistate reactivity patterns. It starts in the singlet ground state of the iron(II)-superoxo reactant and then proceeds mainly on the quintet and triplet surfaces. The initial and rate-determining attack of the superoxo group on the cysteinate sulfur atom involves a spin-state crossing from singlet to quintet. We have also investigated an alternative mechanism via a persulfenate intermediate, with a realignment of hydrogen bonding interactions in the substrate binding pocket. However, this alternative mechanism of proximal oxygen atom attack on the sulfur atom of cysteinate is computed to be a high-energy pathway, and therefore, the persulfenate intermediate is unlikely to participate in the catalytic cycle of CDO enzymes. © 2011 American Chemical Society.


Sudarsanam P.,Indian Institute of Chemical Technology | Katta L.,University of Udine | Thrimurthulu G.,University Pierre and Marie Curie | Reddy B.M.,Indian Institute of Chemical Technology
Journal of Industrial and Engineering Chemistry | Year: 2013

The present study was undertaken to develop a novel and easy practical approach for synthesis of cyclopentanone, a versatile industrial ingredient. Accordingly, ceria-zirconia based nano-oxide catalysts, namely, CexZr1-xO2 and CexZr1-xO2/M (M=SiO2 and Al2O3) were prepared and evaluated for the title reaction. The physicochemical characterization has been achieved using different techniques, namely, XRD, BET surface area, XPS, Raman, OSC, and HREM. The catalytic results revealed that CexZr1-xO2 based nano-oxides are promising heterogeneous catalysts for synthesis of cyclopentanone. Amongst, the CexZr1-xO2/Al2O3 catalyst exhibited ~100% conversion with 75% desired cyclopentanone product selectivity owing to its favorable physicochemical characteristics. © 2013 The Korean Society of Industrial and Engineering Chemistry.


Sudhakar C.,Organic Division I | Reddy P.R.,Organic Division I | Kumar C.G.,Indian Institute of Chemical Technology | Sujitha P.,Indian Institute of Chemical Technology | Das B.,Organic Division I
European Journal of Organic Chemistry | Year: 2012

Putaminoxin E, a natural nonanolide, and its C-9 epimer were synthesized for the first time starting from pentane-1,5-diol and butyraldehyde. The synthetic sequences involve Maruoka asymmetric allylation, Sharpless kinetic resolution, and ring-closing metathesis as the key steps. The cytotoxic and antimicrobial activities of these compounds were evaluated. Putaminoxin E, a natural nonanolide, and its C-9 epimer were synthesized for the first time starting from pentane-1,5-diol and butyraldehyde. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Iqbal J.,University of Hyderabad | Tangellamudi N.D.,University of Hyderabad | Dulla B.,University of Hyderabad | Dulla B.,Indian Institute of Chemical Technology | Balasubramanian S.,University of Regensburg
Organic Letters | Year: 2012

Functionalized β-aryl alanine ester derivatives were found to undergo rapid C-N and C-O bond formation with quinol carbonyl compounds to afford 2H-benzo[b][1,4]oxazines in good to excellent yields. This unprecedented finding reported herein offers a straightforward, highly efficient, and rapid method for the synthesis of 2H-benzo[b][1,4]oxazines. © 2012 American Chemical Society.


Sundararaju B.,French National Center for Scientific Research | Achard M.,French National Center for Scientific Research | Sharma G.V.M.,Indian Institute of Chemical Technology | Bruneau C.,French National Center for Scientific Research
Journal of the American Chemical Society | Year: 2011

A selective C(3)-alkylation via activation/functionalization of sp 3 C-H bond of saturated cyclic amines was promoted by (arene)ruthenium(II) complexes featuring a bidentate phosphino-sulfonate ligand upon reaction with aldehydes. This highly regioselective sustainable transformation takes place via initial dehydrogenation of cyclic amines and hydrogen autotransfer processes. © 2011 American Chemical Society.


Kumar D.,Indian Institute of Chemical Technology | Karamzadeh B.,University of Manchester | Sastry G.N.,Indian Institute of Chemical Technology | De Visser S.P.,University of Manchester
Journal of the American Chemical Society | Year: 2010

The cytochromes P450 are a versatile range of mono-oxygenase enzymes that catalyze a variety of different chemical reactions, of which the key reactions include aliphatic hydroxylation and C=C double bond epoxidation. To establish the fundamental factors that govern substrate epoxidation by these enzymes we have done a systematic density functional theory study on substrate epoxidation by the active species of P450 enzymes, namely the iron(IV)-oxo porphyrin cation radical oxidant or Compound I. We show here, for the first time, that the rate constant of substrate epoxidation, and hence the activation energy, correlates with the ionization potential of the substrate as well as with intrinsic electronic properties of the active oxidant such as the polarizability volume. To explain these findings we present an electron-transfer model for the reaction mechanism that explains the factors that determine the barrier heights and developed a valence bond (VB) curve crossing mechanism to rationalize the observed trends. In addition, we have found a correlation for substrate epoxidation reactions catalyzed by a range of heme and nonheme iron(IV)-oxo oxidants with the strength of the O-H bond in the iron-hydroxo complex, i.e. BDEOH, which is supported by the VB model. Finally, the fundamental factors that determine the regioselectivity change between substrate hydroxylation and epoxidation are discussed. It is shown that the regioselectivity of aliphatic hydroxylation versus double bond epoxidation is not influenced by the choice of the oxidant but is purely substrate dependent. © 2010 American Chemical Society.


Kumar D.,Babasaheb Bhimrao Ambedkar University | Kumar D.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology | De Visser S.P.,University of Manchester
Journal of Physical Chemistry B | Year: 2012

The cytochromes P450 are important iron-heme based monoxygenases that catalyze a range of different oxygen atom transfer reactions in nature. One of the key bioprocesses catalyzed by these enzymes is the aromatic hydroxylation of unactivated arenes. To gain insight into axial ligand effects and, in particular, how it affects aromatic hydroxylation processes by P450 model complexes, we studied the effects of the axial ligand on spectroscopic parameters (trans-influence) as well as on aromatic hydroxylation kinetics (trans-effect) using a range of [FeIV(O)(Por+•)X] oxidants with X = SH-, Cl-, F-, OH-, acetonitrile, GlyGlyCys-, CH3COO-, and CF 3COO-. These systems give red-shifted Fe-O vibrations that are dependent on the strength of the axial ligand. Despite structural changes, however, the electron affinities of these oxidants are very close in energy, but sharp differences in pKa values are found. The aromatic hydroxylation of the para-position of ethylbenzene was tested with these oxidants, and they all show two-state-reactivity patterns although the initial low-spin C-O bond formation barrier is rate determining. We show, for the first time, that the rate determining barrier for aromatic hydroxylation is proportional to the strength of the O-H bond in the corresponding iron(IV)-hydroxo complex, i.e., BDEOH, hence this thermochemical property of the oxidant drives the reaction and represents the axial ligand effect. We have rationalized our observed barrier heights for these axially ligated systems using thermochemical cycles and a valence bond curve crossing diagram to explain the origins of the rate constants. © 2011 American Chemical Society.


Sarkar M.,Indian Institute of Chemical Technology | Bhowmick S.,Indian Institute of Chemical Technology | Casola A.,University of Texas Medical Branch | Chaudhuri K.,Indian Institute of Chemical Technology
FEBS Journal | Year: 2012

Interleukin (IL)-8 is an important mediator in neutrophil-mediated acute inflammation. We previously demonstrated that incubation of intestinal epithelial cells with Vibrio cholerae O395 resulted in increased IL-8 mRNA expression and IL-8 secretion, which was associated with the adherence and motility of bacteria. However, the mechanisms responsible for transcriptional regulation of the IL-8 gene in epithelial cells during V. cholerae infections were not explored. Transient transfection analysis of 5′ deletions and mutations of the IL-8 promoter driving expression of the luciferase reporter gene indicates that multiple binding sites contribute to IL-8 promoter induction in response to V. cholerae and that cooperation among these different sites is required for full activation of the promoter. Stimulation with V. cholerae O395 insertional mutants, defective in adherence and motility, significantly reduced IL-8 promoter activity compared with the wild-type strain. We further demonstrate maximal involvement of extracellular signal-regulated kinase 1/2/mitogen-activated protein kinase pathways to regulate IL-8 gene transcription. This study will help to design agents which could reduce the V. cholerae-induced inflammatory response and in the generation of safe vaccines. © 2012 The Authors Journal compilation © 2012 FEBS.


Kumar D.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology | De Visser S.P.,University of Manchester
Chemistry - A European Journal | Year: 2011

Cytochromes P 450 catalyze a range of different oxygen-transfer processes including aliphatic and aromatic hydroxylation, epoxidation, and sulfoxidation reactions. Herein, we have investigated substrate sulfoxidation mediated by models of P 450 enzymes as well as by biomimetic oxidants using density functional-theory methods and we have rationalized the sulfoxidation reaction barriers and rate constants. We carried out two sets of calculations: first, we calculated the sulfoxidation by an iron(IV)-oxo porphyrin cation radical oxidant [FeIV=O(Por+.)SH] that mimics the active site of cytochrome P 450 enzymes with a range of different substrates, and second, we studied one substrate (dimethyl sulfide) with a selection of different iron(IV)-oxo porphyrin cation radical oxidants [FeIV=O(Por +.)L] with varying axial ligands L. The study presented herein shows that the barrier height for substrate sulfoxidation correlates linearly with the ionization potential of the substrate, thus reflecting the electron-transfer processes in the rate-determining step of the reaction. Furthermore, the axial ligand of the oxidant influences the pKa value of the iron(IV)-oxo group, and, as a consequence, the bond dissociation energy (BDEOH) value correlates with the barrier height for the reverse sulfoxidation reaction. These studies have generalized substrate-sulfoxidation reactions and have shown how they fundamentally compare with substrate hydroxylation and epoxidation reactions. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sundararaju B.,French National Center for Scientific Research | Tang Z.,French National Center for Scientific Research | Achard M.,French National Center for Scientific Research | Sharma G.V.M.,Indian Institute of Chemical Technology | And 2 more authors.
Advanced Synthesis and Catalysis | Year: 2010

An unprecented N- and C(3)-dialkylation of unactivated amines by a cascade reaction via borrowing hydrogen methodology using new (arene)ruthenium(II) complexes featuring phosphinosulfonate ligands is described. This reaction is highly regioselective and produces water as the only side product. Copyright © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sundararaju B.,French National Center for Scientific Research | Achard M.,French National Center for Scientific Research | Demerseman B.,French National Center for Scientific Research | Toupet L.,Rennes Institute of Physics | And 2 more authors.
Angewandte Chemie - International Edition | Year: 2010

(Figure Presented) Branching out: A new ruthenium(IV) complex (1), containing a P,O-chelating ligand, is an efficient precatalyst for regioselective allylations starting from various allylic alcohol derivatives. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.


Reddy P.V.L.,University of Texas Elpaso | Reddy P.V.L.,Indian Institute of Chemical Technology | Kim K.-H.,Hanyang University
Journal of Hazardous Materials | Year: 2015

Pesticides are renowned as some of the most pernicious chemicals known to humankind. Nine out of twelve most hazardous and persistent organic chemicals on planet have been identified as pesticides and their derivatives. Because of their strong recalcitrant nature, it often becomes a difficult task to treat them by conventional approaches. It is well perceived that many factors can interfere with the degradation of pesticides under ambient conditions, e.g., media, light intensity, humic content, and other biological components. However, for the effective treatment of pesticides, photochemical methods are viewed as having clear and perceivable advantages. In this article, we provide a review of the fundamental characteristics of photochemical approaches for pesticide treatment and the factors governing their capacity and potential in such a process. © 2014 Elsevier B.V.


Joly D.,French National Center for Scientific Research | Tondelier D.,Ecole Polytechnique - Palaiseau | Deborde V.,French National Center for Scientific Research | Delaunay W.,French National Center for Scientific Research | And 5 more authors.
Advanced Functional Materials | Year: 2012

The control of the doping ratio of a blue-emitting matrix by an orange emitter with high accuracy still remains very challenging in the development of reproducible white organic light-emitting diodes (WOLEDs). In this work, the development of an organophosphorus dopant that presents a high doping rate in order to reach white emission is reported. The increase of the doping rate has a small impact on the CIE co-ordinates and on the EQE. These results are very appealing towards the development of "easy-to-make" WOLEDS. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Au W.W.,University of Texas Medical Branch | Giri A.K.,Indian Institute of Chemical Technology | Ruchirawat M.,Chulabhorn Research Institute
International Journal of Hygiene and Environmental Health | Year: 2010

A variety of biomarkers have been used to monitor exposed populations to determine potential health hazards from their exposure to environmental toxic agents. However, the majority of these biomarkers have been focused onto the identification of biological damage from the exposure. Therefore, there is a need to develop functional biomarkers that can identify exposure-induced functional deficiencies. More importantly, these deficiencies should be positioned along pathways that are responsible for the development of specific diseases. One of such pathways belongs to the extensive and complex DNA-repair machinery. The machinery thus becomes a large target for damage from environmental toxic agents. The hypothesis is that damage to any component of a repair pathway will interfere with the pathway-specific repair activities. Therefore, when cells from exposed populations are challenged with a DNA-damaging agent in vitro, the in vivo exposure-induced repair deficiency will be dramatically amplified and the deficiency will be detectable in a challenge assay as increased chromosome aberrations, micronuclei or un-repaired DNA strand breaks. The challenge assay has been used in different laboratories to show that a variety of exposed populations (with exposure to air pollutants, arsenic, benzene, butadiene, cigarette smoke, incense smoke, lead, mercury, pesticides, uranium or xylene but not to low concentrations of air pollutants or butadiene) expressed abnormal challenge response. The predicted health consequences of some of these studies have also been validated. Therefore, the challenge assay is a useful functional biomarker for population studies. Details of the challenge assay and its application will be presented in this review. © 2009 Elsevier GmbH. All rights reserved.


Mahadevi A.S.,Indian Institute of Chemical Technology | Rahalkar A.P.,University of Pune | Gadre S.R.,University of Pune | Gadre S.R.,Indian Institute of Technology Kanpur | Sastry G.N.,Indian Institute of Chemical Technology
Journal of Chemical Physics | Year: 2010

An exhaustive study on the clusters of benzene (Bz)n, n=2-8, at MP2/6-31++ G level of theory is reported. The relative strengths of CH-π and π-π interactions in these aggregates are examined, which eventually govern the pattern of cluster formation. A linear scaling method, viz., molecular tailoring approach (MTA), is efficiently employed for studying the energetics and growth patterns of benzene clusters consisting up to eight benzene (Bz) units. Accuracy of MTA-based calculations is appraised by performing the corresponding standard calculations wherever possible, i.e., up to tetramers. For benzene tetramers, the error introduced in energy is of the order of 0.1 mH (∼0.06 kcal/mol). Although for higher clusters the error may build up, further corrections based on many-body interaction energy analysis substantially reduce the error in the MTA-estimate. This is demonstrated for a prototypical case of benzene hexamer. A systematic way of building up a cluster of n monomers (n -mer) which employs molecular electrostatic potential of an (n-1) -mer is illustrated. The trends obtained using MTA method are essentially identical to those of the standard methods in terms of structure and energy. In summary, this study clearly brings out the possibility of effecting such large calculations, which are not possible conventionally, by the use of MTA without a significant loss of accuracy. © 2010 American Institute of Physics.


Sen M.,Indian Institute of Technology Kanpur | Emayavaramban B.,Indian Institute of Technology Kanpur | Barsu N.,Indian Institute of Technology Kanpur | Premkumar J.R.,Indian Institute of Chemical Technology | Sundararaju B.,Indian Institute of Technology Kanpur
ACS Catalysis | Year: 2016

Efficient, atom-economical, highly regioselective C(sp3)-H bond alkenylation of 8-methylquinoline catalyzed by (Cp∗)Co(III) is reported. A well-defined, air-stable, molecular cobalt catalyst, Cp∗Co(III), is employed for the first time in C(sp3)-H bond activation. The developed methodology is broadly applicable and tolerates a variety of functional groups, under mild conditions. Experimental and density functional theory (DFT) results suggest that the initial cyclometalation was occurred via an external-base-assisted concerted metalation deprotonation pathway. © 2016 American Chemical Society.


Chandrasekhar V.,Indian Institute of Technology Kanpur | Mahanti B.,Indian Institute of Technology Kanpur | Bandipalli P.,Indian Institute of Chemical Technology | Bhanuprakash K.,Indian Institute of Chemical Technology
Inorganic Chemistry | Year: 2012

The reaction of the cyclometalated chloro-bridged iridium(III) dimers [(ppy) 2 Ir(μ-Cl)] 2 (ppyH = 2-phenyl pyridine) and [(tpy) 2Ir(μ-Cl)] 2 (tpyH = 2-p-tolylpyridine) with 3,5-diphenylpyrazole (Ph 2PzH) in the presence of sodium methoxide resulted in the formation of heterobridged dimers [(ppy) 2Ir(μ-OH) (μ-Ph 2Pz)Ir(ppy) 2] (1) and [(tpy) 2Ir(μ- OH)(μ-Ph 2Pz)Ir(tpy) 2] (2). Interestingly, the reaction of [(ppy) 2Ir(μ-Cl)] 2 with 3(5)-methyl-5(3)- phenylpyrazole (PhMePzH) afforded both a heterobridged dimer, [(ppy) 2Ir(μ-OH)(μ-PhMePz)Ir(ppy) 2] (3), and the monomer [(ppy) 2Ir(PhMePz)Cl] (4). The compound [(ppy) 2Ir(PhMePz) OH] (5) containing a terminal OH was obtained in a hydrolysis reaction involving 4, sodium methoxide, and PhMePzH. Complexes 1-5 were characterized by X-ray crystallography and electrospray ionization high-resolution mass spectrometry. All of the complexes are luminescent at room temperature in their dichloromethane solutions. The luminescence of the dinuclear complexes is characterized by a single structureless band centered at λ max = 550 nm (1 and 3) and 546 nm (2). The emission spectra of the mononuclear complexes 4 and 5 display vibronic structures with their λ max values at 497 nm (4) and 513 nm (5). In each case, the main emission bands are accompanied by shoulder bands at 526 (4) and 534 nm (5). The quantum yields, calculated with reference to [Ir(ppy) 2(bpy)]PF 6 (φCH 3CN = 0.0622), range from 0.11 to 0.17 for the dinuclear complexes and 0.045 to 0.048 for the mononuclear complexes. The lifetimes of the emission are in the microsecond region, suggesting the phosphorescent nature of the emission. Density functional theory (DFT) and time-dependent DFT calculations were performed on complexes 1 and 4 in the ground state to gain insight into the structural, electronic, and photophysical properties. Electrochemical studies on complexes 1-3 showed the presence of two consecutive one-electron-oxidation processes, assigned as the stepwise oxidation of the two Ir III centers, i.e., Ir III-Ir III/Ir III-Ir IV and Ir III-Ir IV/Ir IV-Ir IV couples, respectively. The monomers displayed single-oxidation peaks. No reduction process was observed within the solvent cathodic potential limit. © 2012 American Chemical Society.


Viault G.,CNRS Chemistry Institute of Rennes | Gree D.,CNRS Chemistry Institute of Rennes | Das S.,Indian Institute of Chemical Technology | Yadav J.S.,Indian Institute of Chemical Technology | Gree R.,CNRS Chemistry Institute of Rennes
European Journal of Organic Chemistry | Year: 2011

The synthesis of new derivatives of embelin, a natural inhibitor of X-linked inhibitor of apoptosis protein (XIAP) is described. The design of these new molecules involved introduction of aromatic groups directly linked to the benzoquinone core. To allow a large flexibility in the nature and the length of the added chain, the strategy involves first aSuzuki-Miyaura reaction with functionalized aromatics, yielding a first generation of molecules. Then, by appropriate use of the functional groups, a second generation of representative embelin derivatives was prepared. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Ghosh R.,Indian Institute of Chemical Technology | Mukherjee M.,Presidency University of India | Chattopadhyay K.,Indian Institute of Chemical Technology | Ghosh S.,Presidency University of India
Journal of Physical Chemistry B | Year: 2012

MPT63, a secreted protein of unknown function that is specific to Mycobacterium tuberculosis and a potential drug target, contains four Tryptophan (Trp/W) residues located at positions 26, 48, 82, and 129 in the amino acid sequence. All of the four Trp residues have been optically resolved by simple inexpensive phosphorescence spectroscopy at 77 K. The protein architecture provides a delicate micro-environment and location of Trp residues giving rise to four different (0,0) bands in the phosphorescence spectra. Calculation of intra Trp energy transfer (ET) efficiency, accessible surface area (ASA) of Trp residues, and environment of Trp in the wild-type (WT) and the mutant W26F [where, Trp 26 is replaced by phenyl alanine (Phe/F)] reveal: ET1 (W82) > ET1 (W48) > ET1 (W129) > ET1 (W26), where ET1 is the lowest (φ-φ*) triplet state energy of Trp. The (0,0) band observed at 421.6 nm assigned for Trp 26 is found to be the longest wavelength (0,0) band so far reported in the literature. Fluorescence in WT and W26F is dominated by buried or partially exposed Trp residues indicated by time-resolved spectra. Circular Dichroism (CD) studies and the time-resolved anisotropy measurement confirm the unaltered secondary and tertiary structure of the mutant compared to that of the WT. Excitation energy dependent phosphorescence spectra suggest that the intensity of the different (0,0) bands could be tuned and Tyrosine (Tyr/Y) residue is silent in emission. Optical resolution of all the Trp residues will help understand the role of each Trp residue in the folding/unfolding mechanism and in the interaction with other systems. © 2012 American Chemical Society.


Bhattacharya A.,Presidency University of India | Biswas A.,Indian Institute of Chemical Technology | Das P.K.,Indian Institute of Chemical Technology
Molecular Microbiology | Year: 2012

cAMP-mediated responses act as modulators of environmental sensing and cellular differentiation of many kinetoplastidae parasites including Leishmania. Although cAMP synthesizing (adenylate cyclase) and degrading (phosphodiesterase) enzymes have been cloned and characterized from Leishmania, no cAMP-binding effector molecule has yet been identified from this parasite. In this study, a regulatory subunit of cAMP-dependent protein kinase (Ldpkar1), homologous to mammalian class I cAMP-dependent protein kinase regulatory subunit, has been identified from L.donovani. Further characterization suggested possible interaction of LdPKAR1 with PKA catalytic subunits and inhibition of PKA activity. This PKA regulatory subunit is expressed in all life cycle stages and its expression attained maximum level in stationary phase promastigotes, which are biochemically similar to the infective metacyclic promastigotes. Starvation condition, the trigger for metacyclogenesis in the parasite, elevates LdPKAR1 expression and under starvation condition promastigotes overexpressing Ldpkar1 attained metacyclic features earlier than normal cells. Furthermore, Ldpkar1 overexpression accelerates autophagy, a starvation-induced cytological event necessary for metacyclogenesis and amastigote formation. Conditional silencing of Ldpkar1 delays the induction of autophagy in the parasite. The study, for the first time, reports the identification of a functional cAMP-binding effector molecule from Leishmania that may modulate important cytological events affecting metacyclogenesis. © 2011 Blackwell Publishing Ltd.


Singh S.P.,Indian Institute of Chemical Technology | Roy M.S.,Defence Laboratory | Thomas K.R.J.,Indian Institute of Technology Roorkee | Balaiah S.,Indian Institute of Chemical Technology | And 3 more authors.
Journal of Physical Chemistry C | Year: 2012

We synthesized two organic dyes (TPA-CN1-R2 and TPA-CN2-R1) based on the TPA core unit having structure A-D-A, which contain the triphenylamine moiety as an electron donor and both cyanovinylene 4-nitrophenyl and carboxylic (anchoring) units as electron acceptors. Nanocrystalline TiO 2-based dye-sensitized solar cells (DSSCs) were fabricated using these dyes to investigate the effect of number of anchoring groups on their photovoltaic performance. The DSSCs based on TPA-CN1-R2 and TPA-CN2-R1 showed power conversion efficiency (PCE) of about 2.36% and 1.41%, respectively. The PCE has been significantly improved up to 4.37% and 2.8%, upon addition of 20 mM deoxycholic acid (DCA) to the dye solution for TiO 2 sensitization. Coadsorption of DCA decreased dye coverage but significantly improved the value of the short-circuit photocurrent (J sc). The breakup of π-stacked aggregates might improve the electron injection yield and thus J sc. Electrochemical impedance spectra and current-voltage characteristics in the dark indicate that the electron lifetime was improved by coadsorption of DCA, accounting for the significant improvement of open-circuit voltage (V oc). © 2012 American Chemical Society.


Mohanakrishna G.,Indian Institute of Chemical Technology | Krishna Mohan S.,Indian Defence Research And Development Laboratory | Venkata Mohan S.,Indian Institute of Chemical Technology
Applied Energy | Year: 2012

Carbon based multiwalled nanotubes (MWCNT) and nanopowder (CNP) impregnated using conductive epoxy resin on anodic surface were evaluated for bioelectricity generation in single chambered microbial fuel cells in comparison with plain graphite anode (MFCP). The study demonstrated the positive function of carbon nano structures impregnated anode with respect to power generation. MFCMWCNT exhibited higher electrogenic activity (267.77mW/m2) followed by MFCCNP (168.45mW/m2) and MFCP (107.51mW/m2). MFCMWCNT and MFCCNP showed 148% and 57% enhancement in the power generation respectively compared to MFCP. Microbial mediators were also found to be more effective with modified anodes operation. Impregnation with nano material facilitates higher surface area that enables higher charge transfer from anolyte to electrodes. Impregnated anodes showed marginal influence on substrate degradation. Further, feasibility of MWCNT impregnated anode was evaluated with real field distillery wastewater which depicted good electrogenic activity (245.34mW/m2) and yield (3.43W/m3). © 2012 Elsevier Ltd.


Vinod V.T.P.,Indian Department of Atomic Energy | Saravanan P.,Indian Defence Research And Development Laboratory | Sreedhar B.,Indian Institute of Chemical Technology | Devi D.K.,Indian Institute of Chemical Technology | Sashidhar R.B.,Osmania University
Colloids and Surfaces B: Biointerfaces | Year: 2011

An environmentally benign method for the synthesis of noble metal nanoparticles has been reported using aqueous solution of gum kondagogu (Cochlospermum gossypium). Both the synthesis, as well as stabilization of colloidal Ag, Au and Pt nanoparticles has been accomplished in an aqueous medium containing gum kondagogu. The colloidal suspensions so obtained were found to be highly stable for prolonged period, without undergoing any oxidation. SEM-EDXA, UV-vis spectroscopy, XRD, FTIR and TEM techniques were used to characterize the Ag, Au and Pt nanoparticles. FTIR analysis indicates that -OH groups present in the gum matrix were responsible for the reduction of metal cations into nanoparticles. UV-vis studies showed a distinct surface plasmon resonance at 412 and 525. nm due to the formation of Au and Ag nanoparticles, respectively, within the gum network. XRD studies indicated that the nanoparticles were crystalline in nature with face centered cubic geometry. The noble metal nanoparticles prepared in the present study appears to be homogeneous with the particle size ranging between 2 and 10. nm, as evidenced by TEM analysis. The Ag and Au nanoparticles formed were in the average size range of 5.5 ± 2.5 nm and 7.8 ± 2.3 nm; while Pt nanoparticles were in the size range of 2.4 ± 0.7. nm, which were considerably smaller than Ag and Au nanoparticles. The present approach exemplifies a totally green synthesis using the plant derived natural product (gum kondagogu) for the production of noble metal nanoparticles and the process can also be extended to the synthesis of other metal oxide nanoparticles. © 2010 Elsevier B.V.


Amali A.J.,Indian Institute of Chemical Technology | Saravanan P.,Indian Defence Research And Development Laboratory | Rana R.K.,Indian Institute of Chemical Technology
Angewandte Chemie - International Edition | Year: 2011

Chains for the better: A poly(L-lysine)-mediated self-assembly of citrate-functionalized Fe3O4 nanoparticles and hydroxy pyrene trisulfonate (HPTS) forms magnetoresponsive fluorescent spheres (MFS) in the presence of glutaric dialdehyde (GA). If the assembly is performed in the presence of a permanent magnet then 1D magnetic beaded-chain structures are formed (see scheme). © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Kulkarni A.,Indian Institute of Chemical Technology | Naveen Kumar B.S.C.,Indian Institute of Chemical Technology | Ravi V.,Banking Technology | Murthy U.S.,Indian Institute of Chemical Technology
Expert Systems with Applications | Year: 2011

Microarray data provides information on gene expression levels of thousands of genes in a cell in a single experiment. DNA microarray is a powerful tool in the diagnosis of cancer. Numerous efforts have been made to use gene expression profiles to improve precision of tumor classification. In this study comparison between class prediction accuracy of two different classifiers, Genetic Programming and Genetically Evolved Decision Trees, was carried out using the best 10 and best 20 genes ranked by the t-statistic and mutual information. Genetic Programming proved out to be the better classifier for this dataset based on area under the receiver operating characteristic curve (AUC) and total accuracy using mutual information based feature selection. We conclude that Genetic Programming together with mutual information based feature selection is the most efficient alternative to the existing colon cancer prediction techniques. © 2010 Elsevier Ltd. All rights reserved.


Avasarala B.K.,Andhra University | Tirukkovalluri S.R.,Andhra University | Bojja S.,Indian Institute of Chemical Technology
Journal of Hazardous Materials | Year: 2011

Mg-doped TiO 2 with different Mg concentrations were prepared using sol-gel method and characterized by XRD, UV-visible, XPS, SEM and FT-IR. The XRD results revealed that Mg 2+ goes into the TiO 2 lattice. SEM images of the doped and pure TiO 2 indicated that there is a smaller particle size for the doped catalyst compared to that of the pure TiO 2. UV-visible absorption spectra indicated that upon doping with Mg 2+ ion, the catalyst exhibits absorption in visible region. FT-IR and XPS spectra demonstrated that the presence of Mg 2+ ion in the TiO 2 lattice as substitutional dopant. Photocatalytic activity of doped TiO 2 has been evaluated by degradation of the monocrotophos (MCP) pesticide. The effect of solution pH, catalyst dosage and initial concentration of MCP on the photocatalytic activity of Mg-doped TiO 2 with different loadings was studied. It was observed that the rate of degradation of MCP over Mg-doped TiO 2 is better than Pure TiO 2 and Degussa P-25. © 2010 Elsevier B.V.


Patil M.K.,Dr. Babasaheb Ambedkar Marathwada University | Prasad A.N.,Indian Institute of Chemical Technology | Reddy B.M.,Indian Institute of Chemical Technology
Current Organic Chemistry | Year: 2011

This review highlights the application of sulfated, molybdated and tungstated zirconia solid acid catalysts, and their modified forms for variety of organic synthesis and transformation reactions in the liquid phase. Most of these catalysts offer significant improvements in various organic reactions with regard to the yield of products, simplicity in the operation, reusability of the catalysts and green features by avoiding toxic conventional catalysts. Preparation of various zirconia-based solid acid catalysts has been briefly described. Characterization of these catalysts by different techniques has also been presented. Most of these catalysts are highly promising for numerous organic reactions in the liquid phase which include condensation, isomerization, esterification and transesterification, muticomponent reactions and so on. © 2011 Bentham Science Publishers.


Guha R.,Indian Institute of Chemical Technology | Gupta D.,National Institute of Immunology | Rastogi R.,National Institute of Immunology | Vikram R.,National Institute of Immunology | And 4 more authors.
Science Translational Medicine | Year: 2013

Leishmaniasis is a severe infectious disease. Drugs used for leishmaniasis are very toxic, and no vaccine is available. We found that the hemoglobin receptor (HbR) of Leishmania was conserved across various strains of Leishmania, and anti-HbR antibody could be detected in kala-azar patients' sera. Our results showed that immunization with HbR-DNA induces complete protection against virulent Leishmania donovani infection in both BALB/c mice and hamsters. Moreover, HbR-DNA immunization stimulated the production of protective cytokines like interferon-γ (IFN-γ), interleukin-12 (IL-12), and tumor necrosis factor-α (TNF-α) with concomitant down-regulation of disease-promoting cytokines like IL-10 and IL-4. HbR-DNA vaccination also induced a protective response by generating multifunctional CD4+ and CD8+ T cells. All HbR-DNA-vaccinated hamsters showed sterile protection and survived during an experimental period of 8 months. These findings demonstrate the potential of HbR as a vaccine candidate against visceral leishmaniasis.


Raji Reddy C.,Indian Institute of Chemical Technology | Vijaykumar J.,Indian Institute of Chemical Technology | Gree R.,CNRS Chemistry Institute of Rennes
Synthesis (Germany) | Year: 2013

A new and efficient metal-free, two-component, one-pot approach to a variety of 3,5-disubstituted 1H-pyrazoles has been developed from propargylic alcohols. This transformation proceeds via an acid-catalyzed propargylation of N,N-diprotected hydrazines followed by base-mediated 5-endo-dig cyclization leading to 3,5-disubstituted 1H-pyrazoles in good overall yields.© Georg Thieme Verlag Stuttgart. New York.


Thomas A.,Indian Institute of Chemical Technology | Bhanuprakash K.,Indian Institute of Chemical Technology | Prasad K.M.M.K.,Andhra University
Journal of Physical Organic Chemistry | Year: 2011

Main factors responsible for the red to near infrared (NIR) absorption of the benzobis(1,2,5-thiadiazole) (BBT) derivatives have been investigated using high level computational studies. These molecules with NIR emission are of importance due to the recent reports of possible role in NIR organic light emitting diodes (OLED) development. The electronic structure has been determined using closed-shell/open-shell DFT methods (B3LYP and BHandHLYP). The wavefunction stabilities of these BBT derivatives have been tested. We notice that using the BHandHLYP functional, the wave function becomes instable though large HOMO-LUMO gaps (HLG) are obtained. On the other hand a stable wavefunction is obtained using the B3LYP functional but the HLG is small. The B3LYP HLG is in good agreement with the available experimental data. Nevertheless results from both functionals indicate a possible LUMO occupation/biradicaloid character (BRC). We calculated the BRC for all the molecules using different methods and observed that these molecules have a large BRC which correlates well with excitation energies. Larger the BRC smaller the excitation energy. Charge transfer based on Mulliken charges of both ground and excited state are obtained from high level SAC/SAC-CI studies. We carried out the VB studies of the unsubstituted BBT to predict the relative weights of the individual Lewis structures to the resonance picture. It is concluded that a more general description which include the zwitterionic and biradical structures are necessary for these molecules and not just simple donor-acceptor-donor (D-A-D) structures as suggested in the literature. Copyright © 2010 John Wiley & Sons, Ltd.


Borkar P.,CNRS Chemistry Institute of Rennes | Borkar P.,Indian Institute of Chemical Technology | Van De Weghe P.,CNRS Chemistry Institute of Rennes | Reddy B.V.S.,Indian Institute of Chemical Technology | And 2 more authors.
Chemical Communications | Year: 2012

Novel synergistic effects between Lewis and Bronsted acids in Prins cyclization are reported. Non-reactive Lewis acids and non-reactive Bronsted acids, which failed to perform Prins cyclization when used alone, have shown remarkable synergistic effects when used in combination to perform the reaction successfully. © 2012 The Royal Society of Chemistry.


Reddy C.R.,Indian Institute of Chemical Technology | Vijaykumar J.,Indian Institute of Chemical Technology | Gree R.,CNRS Chemistry Institute of Rennes
Synthesis | Year: 2010

Tris(pentafluorophenyl)borane has found to be an effective catalyst for the alkylation of 1,3-dicarbonyl compounds using benzylic alcohols as alkylating agents. Various 1,3-dicarbonyl compounds reacted cleanly with different benzylic alcohols to provide the corresponding monoalkylated products in good yield. In addition tris(pentafluorophenyl)borane efficiently promoted the C3 alkylation of 4-hydroxycoumarins. Further, several oxygenated heterocycles such as furans, 4H-chromenes, and furanocoumarins have been prepared using the described methodology as the key step. © Georg Thieme Verlag Stuttgart New York.


Banerjee B.,Indian Institute of Chemical Technology | Roy A.,Indian Institute of Chemical Technology | Sen N.,Johns Hopkins University | Majumder H.K.,Indian Institute of Chemical Technology
Molecular Microbiology | Year: 2010

Tyrosyl DNA phosphodiesterase 1 (Tdp1) is a member of phospholipase D superfamily, which cleaves a broad range of 3′-DNA adducts, the best characterized of which is the phosphodiester bond formed between DNA and topoisomerase IB. This study describes cloning and functional characterization of the enzyme, termed as LdTdp1 in the kinetoplastid parasite Leishmania donovani. Sequence analysis confirmed conservation of the active site motifs typical for all Tdp1 proteins. LdTdp1 activity was detected in the parasite nucleus as well as in the kinetoplast. The enzyme harbours a nuclear localization signal at its C-terminus. Overexpression of the active enzyme protected the parasites against topoisomerase IB inhibitor camptothecin (CPT) and oxidative agent H 2O 2-mediated cytotoxicity and its downregulation rendered the parasites hypersensitive to CPT. Trapping of mutant LdTdp1 on DNA takes place following CPT treatment in L. donovani cells. The expression level and associated activity of LdTdp1 were found to be higher in CPT-resistant L. donovani parasites. Altogether, this is the first report of Tdp1 from the kinetoplastid parasite L. donovani, which actively participates in topoisomerase I-mediated DNA damage repair process and thereby counteracts the cytotoxic effect of topoisomerase I inhibitors. © 2010 Blackwell Publishing Ltd.


Subash B.,Annamalai University | Krishnakumar B.,Annamalai University | Sreedhar B.,Indian Institute of Chemical Technology | Swaminathan M.,Annamalai University | Shanthi M.,Annamalai University
Superlattices and Microstructures | Year: 2013

The WO3 loaded Ag-ZnO (WO3-Ag-ZnO) was successfully synthesized by precipitation-decomposition method. The catalyst was characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM) images, energy dispersive spectrum (EDS), transmission electron microscope (TEM), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), cyclic voltammetry (CV) and BET surface area measurements. The photocatalytic activity of WO3-Ag-ZnO was investigated for the degradation of Naphthol Blue Black (NBB) in aqueous solution using solar light. WO3-Ag-ZnO is found to be more efficient than Ag-ZnO, WO 3-ZnO, Ag-WO3, WO3, commercial ZnO, bare ZnO, TiO2-P25 and TiO2 (Merck) at pH 9 for the mineralization of NBB dye. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization of NBB dye have been analyzed. The mineralization of NBB has been confirmed by Chemical Oxygen Demand (COD) measurements. A degradation mechanism is proposed for the degradation of NBB under solar light. This catalyst is found to be reusable. © 2012 Elsevier Ltd. All rights reserved.


Nageswara Rao R.,Indian Institute of Chemical Technology | Mastan Vali R.,Indian Institute of Chemical Technology | Vara Prasada Rao A.,Andhra University
Journal of Separation Science | Year: 2012

An efficient and environmental friendly ionic liquid based dispersive liquid-liquid microextraction procedure was optimized for determination of rifaximin in rat serum by reverse phase high-performance liquid chromatography. The effect of ionic liquids, dispersive solvents, extractant/disperser ratio, and salt concentrations on sample recovery and enrichment factors were studied. Among the five ionic liquids studied in the present investigation, 1-butyl-3-methylimidazolium hexafluorophosphate was found to be most effective for extraction of rifaximin. The recovery was found to be more than 98% using 1-butyl-3-methylimidazolium hexafluorophosphate and methanol as extraction and dispersive solvents, at an extractant/disperser ratio of 0.43. The recovery was further enhanced to 99.5% by the addition of 5.0% NaCl solution. A threefold enhancement in detection limit was achieved when compared to protein precipitation. The ionic liquid containing the extracted rifaximin was directly injected into HPLC system. The linear relationship was observed in the range of 0.03-10.0 μg/mL with the correlation coefficient (r2) 0.9998. Limits of detection and quantification were found to be 0.01 and 0.03 μg/mL, respectively. The relative standard deviation was 2.5%. The method was validated and applied to study pharmacokinetics of rifaxmin in rat serum. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Roy P.K.,Presidency University of India | Hens C.,Indian Institute of Chemical Technology | Grosu I.,Victor Babes University of Medicine and Pharmacy Timisoara | Dana S.K.,Presidency University of India
Chaos | Year: 2011

We report a method of engineering generalized synchronization (GS) in chaotic oscillators using an open-plus-closed-loop coupling strategy. The coupling is defined in terms of a transformation matrix that maps a chaotic driver onto a response oscillator where the elements of the matrix can be arbitrarily chosen, and thereby allows a precise control of the GS state. We elaborate the scheme with several examples of transformation matrices. The elements of the transformation matrix are chosen as constants, time varying function, state variables of the driver, and state variables of another chaotic oscillator. Numerical results of GS in mismatched Rössler oscillators as well as nonidentical oscillators such as Rössler and Chen oscillators are presented. © 2011 American Institute of Physics.


Shaik S.,Institute of Chemistry and the Lise Meitner Minerva | Shaik S.,Hebrew University of Jerusalem | Cohen S.,Hebrew University of Jerusalem | Wang Y.,Hebrew University of Jerusalem | And 4 more authors.
Chemical Reviews | Year: 2010

A study was conducted to demonstrate that the structure, reactivity, and selectivity of P450 enzymes were modeled by quantum mechanical/molecular mechanical (QM/MM) calculations. Combined (QM/MM) theory had emerged as one of the most suitable methods for modeling local electronic events in large biomolecular systems and investigate different characteristics of P450 enzymes. The study addressed some of the significant issues relevant to QM/MM studies of such enzymes. It discussed some of the practical issues that arose during QM/MM calculations and introduced notations and conventions. It was revealed that standard QM/MM applications employed a fixed QM/MM partitioning that was defined for all the requirements. The selection of such a method for studying characteristics of enzymes followed the same criteria as in QM investigations.


Patent
Indian Institute of Chemical Technology and National Institute Of Immunology | Date: 2014-04-11

The present invention in general relates Hemoglobin receptor or its part as a novel vaccine candidate against Leishmaniasis. Specifically, the present invention envisages HbR DNA for eliciting immune response in a mammal against Leishmaniasis. Additional aspect of the present invention is related to a vaccine composition for inducing immune response against Leishmaniasis in mammals. In a preferred aspect, the present invention relates to use of HbR-polypeptide as marker for diagnosis of Leishmania in kala-azar patients.


Katta L.,Indian Institute of Chemical Technology | Reddy B.M.,Indian Institute of Chemical Technology | Muhler M.,Ruhr University Bochum | Grunert W.,Ruhr University Bochum
Catalysis Science and Technology | Year: 2012

Titania supported ceria-lanthana solid solutions (Ce xLa 1-xO 2-δ/TiO 2; CLT) have been synthesized by a facile and economical route. Existence of synergism between ceria-lanthana (CL) solid solutions and titania-anatase phase, which leads to decrease in the crystallite size, retarded titania phase transformation, and improved redox properties, has been thoroughly investigated by various techniques, namely, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), Raman spectroscopy (UV-RS and Vis-RS), BET surface area analysis, and temperature programmed reduction (TPR). Two key observations made from the whole exercise were (i) mutual interaction of Ce and Ti ions could impose typical Ce-O-Ti modes at the interfacial region and (ii) the La 3+ ion as a dopant provokes a large number of oxygen vacancies via a charge compensation mechanism. The promising role of these factors in the CO oxidation (one of the most formidable challenges) has been comprehensively described. The observed enhanced activity for the CLT sample is primarily attributed to an apparent specific orientation of the active component over the support, which is endorsed by the interfacial interaction. This specific mode could facilitate the CO adsorption with simultaneous bulk oxygen diffusion for more consumption and in turn better activity. © 2012 The Royal Society of Chemistry.


Datta K.K.R.,Japan National Institute of Materials Science | Datta K.K.R.,Jawaharlal Nehru Centre for Advanced Scientific Research | Reddy B.V.S.,Japan National Institute of Materials Science | Reddy B.V.S.,Indian Institute of Chemical Technology | And 3 more authors.
Angewandte Chemie - International Edition | Year: 2010

Support with triple function: Au nanoparticles with sizes of less than 7 nm were fabricated in the channels of a mesoporous carbon nitride (MCN) support, which acts as a stabilizing, size-controlling, and reducing agent (see picture; Au NPs in green). The embedded, well-dispersed Au nanopartides are a highly active, selective, and recyclable catalyst for the three-component coupling reaction of benzaldehyde, piperidine, and phenylacetylene for the synthesis of propargylamine. Figure Presented © 2010 wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sudarsanam P.,Indian Institute of Chemical Technology | Mallesham B.,Indian Institute of Chemical Technology | Reddy P.S.,Indian Institute of Chemical Technology | Grossmann D.,Ruhr University Bochum | And 2 more authors.
Applied Catalysis B: Environmental | Year: 2014

The present investigation was undertaken to know the influence of different dopants on the physicochemical properties and catalytic behavior of nano-Au/CeO2 catalyst for CO oxidation. Accordingly, various metal ions namely, Fe3+, La3+ and Zr4+ were incorporated into the ceria lattice by a facile coprecipitation approach using ultra-high dilute aqueous solutions. An anion adsorption method was used to prepare the Au/doped-CeO2 catalysts in the absence of any base, reducing and protective agents. The physicochemical characterization was performed by XRD, BET surface area, ICP-AES, TG-DTA, FT-IR, TEM, UV-vis DRS, Raman, XPS and TPD techniques. Doped CeO2 exhibited smaller crystallite size, higher BET surface area and larger amount of oxygen vacancies than the pure CeO2. These remarkable properties showed a beneficial effect toward gold particle size as confirmed by XRD and TEM studies. XPS results revealed that Au is present in the metallic state and Ce in both +3 and +4 oxidation states. Incorporation of Zr into the Au/CeO2 resulted in high CO oxidation activity attributed to the presence of more Ce3+ ions and oxygen vacancies. In contrast, the La-incorporation caused an opposite effect due to the presence of carbonate species on the surface of Au/CeO2-La2O3 catalyst, which blocked the active sites essential for CO oxidation. It was shown that accumulation of carbonate species strongly depends on the acid-base properties of the supports. The catalytic performance of Au catalysts is highly dependent on the nature of the support. © 2013 Elsevier B.V.


Lalitha K.,Indian Institute of Chemical Technology | Sadanandam G.,Indian Institute of Chemical Technology | Kumari V.D.,Indian Institute of Chemical Technology | Subrahmanyam M.,Indian Institute of Chemical Technology | And 2 more authors.
Journal of Physical Chemistry C | Year: 2010

Cu-doped TiO2 with varying amounts of Cu (0.2, 0.3, 0.5, 1, 2, and 5) are prepared by impregnation method and calcined at 350 and 450 °C for 5 h. These catalysts are characterized by X-ray diffraction, diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy energy-dispersive X-ray spectroscopy (EDAX), and transmission electron microscopy (TEM). The DRS studies are clearly showing the expanded photo response of TiO2 into the visible region on impregnation of copper ions. TEM images are depicting the fine dispersion of Cu particles on TiO2 surface. XPS studies are showing change in the binding energy values of Ti 2p, O 1s, and Cu 2p, indicating that copper ions are in interaction with TiO2. XPS results are also confirming that the oxidation state of copper is +2 in samples calcined at 350 °C and +1 in samples calcined at 450 °C. EDAX analysis supports the presence of copper species on the surface layers of TiO2. Photocatalytic hydrogen production activity studies are conducted over CuO/TiO2 and Cu2O/TiO2 catalysts in pure water and glycerol:water mixtures under solar irradiation. Maximum hydrogen production of 265 and 290 μmol h -1 is observed over 2 wt % CuO/TiO2 and Cu2O/TiO 2 catalysts in pure water. A significant improvement in hydrogen production is observed in glycerol:water mixtures and maximum hydrogen production of 16,500 and 20,060 μmol h-1 is obtained over 0.5 wt % CuO/TiO2 and Cu2O/TiO2 catalysts in 5% glycerol aqueous solutions. No hydrogen production activity is observed on reduced catalysts under solar irradiation. Furthermore, when these catalysts are studied under UV irradiation, 2-3 fold increase in activity is observed on calcined catalysts, and the same level of activity is observed on reduced catalysts, but under these conditions the activity is limited by the dissolution of Cu ions into the solution. However, under solar irradiation a continuous and stable activity is observed over Cu2O/TiO2 catalyst. On the basis of the characterization and hydrogen production activity results, finely dispersed Cu in +1 oxidation state that is in interaction with TiO2 is proposed as a promising visible sensitive photocatalyst for the continuous production of hydrogen from glycerol:water mixtures. © 2010 American Chemical Society.


Zhang S.-L.,Southwest University | Damu G.L.V.,Southwest University | Damu G.L.V.,Indian Institute of Chemical Technology | Zhang L.,Southwest University | And 2 more authors.
European Journal of Medicinal Chemistry | Year: 2012

A series of novel benzimidazole derivatives were synthesized and characterized by 1H NMR, 13C NMR, MS, IR and HRMS spectra. All the new compounds were screened for their antimicrobial activities in vitro by two-fold serial dilution technique. Bioactive assay manifested that the bis-benzimidazole derivative 11d and its hydrochloride 13b exhibited remarkable antimicrobial activities, which were comparable or even better than the reference drugs Norfloxacin, Chloromycin and Fluconazole. The interaction evaluation of compound 11d with bovine serum albumin (BSA) by Fluorescence and UV-vis absorption spectroscopic method showed that BSA could generate fluorescent quenching under approximately human physiological conditions by the prepared benzimidazole compound 11d as result of the formation of ground-state compound 11d-BSA complex. The thermodynamic parameters indicated that the hydrogen bonds and van der Waals forces played major roles in the strong association of benzimidazole 11d and BSA. © 2012 Elsevier Masson SAS. All rights reserved.


Ramakumar S.,Pondicherry University | Satyanarayana L.,Indian Institute of Chemical Technology | Manorama S.V.,Indian Institute of Chemical Technology | Murugan R.,Pondicherry University
Physical Chemistry Chemical Physics | Year: 2013

Antimony-doped lithium stuffed garnets Li7-xLa 3Zr2-xSbxO12 (x = 0.2-1.0) prepared using a conventional solid state reaction method are characterized using Powder X-ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), Energy Dispersive Analysis by X-ray (EDAX), AC Impedance spectroscopy, Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) and Raman spectroscopic techniques. PXRD confirms the formation of a garnet-like structure with cubic symmetry for the entire selected compositional range. Among the investigated compounds, the compound with an Sb content corresponding to x = 0.4, i.e. Li 6.6La3Zr1.6Sb0.4O12 exhibits the maximum total (bulk + grain boundary) ionic conductivity of 7.7 × 10-4 S cm-1 at 30 °C. The shape of the imaginary part of the modulus spectra suggests that the relaxation processes are non-Debye in nature. The full width at half maximum (FWHM) for the master modulus curve of Li6.6La3Zr1.6Sb 0.4O12 is found to be the smallest among the investigated lithium garnets. The full width at half maximum (FWHM) of the 7Li MAS NMR spectrum for the composition Li6.6La3Zr 1.6Sb0.4O12 is the smallest among the investigated compounds. Raman data collected for the compounds in this series indicates an increase of Li+ occupancy in the tetrahedrally coordinated site with an associated decrease of Li+ occupancy in the octahedrally coordinated site during an increase of x in Li7-xLa 3Zr2-xSbxO12. The present investigation reveals that the optimal Li+ concentration required to achieve the maximum room-temperature Li+ conductivity in Li 7-xLa3Zr2-xSbxO12 lithium stuffed garnet is around x = 0.4. © 2013 the Owner Societies.


Vijay D.,Indian Institute of Chemical Technology | Vijay D.,CSIR - Central Leather Research Institute | Sakurai H.,Japan Institute for Molecular Science | Subramanian V.,CSIR - Central Leather Research Institute | Sastry G.N.,Indian Institute of Chemical Technology
Physical Chemistry Chemical Physics | Year: 2012

An exhaustive computational study at the M05-2X/cc-pVDZ level which explores the binding possibilities of cations (Li +, Na +, K + and Cu +) to the concave and convex sides of the hub and rim rings of prototypical buckybowls, sumanene (C 21H 12) and corannulene (C 20H 10), has been carried out. Five distinct minima on the potential energy surface of sumanene and four on the potential energy surface of corannulene were identified. The complex where the metal ion binds to the convex side of the 6-membered rim ring is adjudged as the most stable complex for both the bowls considered. The cation-π interaction energies of buckybowls are compared with model systems such as benzene, cyclopentadiene, indene and coronene. Energy decomposition analysis has also been performed to delineate the contribution from various components contributing to the cation-π binding strength. © 2012 The Owner Societies.


Vijay D.,Indian Institute of Chemical Technology | Sakurai H.,Japan Institute for Molecular Science | Sakurai H.,Japan Science and Technology Agency | Sastry G.N.,Indian Institute of Chemical Technology
International Journal of Quantum Chemistry | Year: 2011

The effect of basis set superposition error (BSSE) on the structure and energy of benzene, naphthalene, corannulene, and sumanene dimer has been analyzed. MP2 method was chosen and the effect is estimated using 6-31G, 6-31G(d), 6-311+G(d), cc-pVDZ, and cc-pVTZ basis sets. The model calculations on benzene dimer indicate that the impact of BSSE on the equilibrium geometry of π-stacked dimers appears to be quite significant. Calculations on larger molecular dimers such as the dimers of naphthalene, corannulene, and sumanene are also studied. The practical implication of the current observation on modeling the macromolecular structure is discussed. Copyright © 2010 Wiley Periodicals, Inc.


Susrutha B.,Indian Institute of Chemical Technology | Giribabu L.,Indian Institute of Chemical Technology | Giribabu L.,CSIR - Central Electrochemical Research Institute | Singh S.P.,Indian Institute of Chemical Technology | Singh S.P.,CSIR - Central Electrochemical Research Institute
Chemical Communications | Year: 2015

Flexible and low-weight thin-film perovskite solar cells have attracted considerable attention for developing large-area, roll-to-roll and differently shaped photovoltaics with improved power conversion efficiencies. In this review, we describe how researchers have adopted different approaches to enhance the device performance of the flexible perovskite solar cells to compete with rigid substrates with tailored electron/hole transport materials and flexible substrates. © 2015 The Royal Society of Chemistry.


Singh S.P.,Indian Institute of Chemical Technology | Singh S.P.,CSIR - Central Electrochemical Research Institute | Gayathri T.,Indian Institute of Chemical Technology | Gayathri T.,CSIR - Central Electrochemical Research Institute
European Journal of Organic Chemistry | Year: 2014

Enhancement of light-harvesting efficiency (LHE) in the red/near-IR (NIR) region (600-1000 nm) of the solar spectrum is a challenge to improvement of the photovoltaic performances of dye-sensitized solar cells (DSSCs). Therefore, design and development of effective red/NIR photosensitizers are currently a hot topic in DSSCs. BODIPY dyes can offer magnificent characteristics such as sharp and moderately strong absorption, large quantum yields, long excited state lifetimes, good solubility and easy chromatographic separation. From this perspective, recent progress in BODIPY-sensitized solar cells is reviewed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Subbalakshmi C.,CSIR - Central Electrochemical Research Institute | Manorama S.V.,Indian Institute of Chemical Technology | Nagaraj R.,CSIR - Central Electrochemical Research Institute
Journal of Peptide Science | Year: 2012

The morphology of structures formed by the self-assembly of short N-terminal t-butyloxycarbonyl (Boc) and C-terminal methyl ester (OMe) protected and Boc-deprotected hydrophobic peptide esters was investigated. We have observed that Boc-protected peptide esters composed of either only aliphatic hydrophobic amino acids or aliphatic hydrophobic amino acids in combination with aromatic amino acids, formed highly organized structures, when dried from methanol solutions. Transmission and scanning electron microscopic images of the peptides Boc-Ile-Ile-OMe, Boc-Phe-Phe-Phe-Ile-Ile-OMe and Boc-Trp-Ile-Ile-OMe showed nanotubular structures. Removal of the Boc group resulted in disruption of the ability to form tubular structures though spherical aggregates were formed. Both Boc-Leu-Ile-Ile-OMe and H-Leu-Ile-Ile-OMe formed only spherical nanostructures. Dynamic light scattering studies showed that aggregates of varying dimensions were present in solution suggesting that self-assembly into ordered structures is facilitated by aggregation in solution. Fourier transform infrared spectroscopy and circular dichroism spectroscopy data show that although all four of the protected peptides adopt well-defined tertiary structures, upon removal of the Boc group, only H-Phe-Phe-Phe-Ile-Ile-OMe had the ability to adopt β-structure. Our results indicate that hydrophobic interaction is a very important determinant for self-assembly and presence of charged and aromatic amino acids in a peptide is not necessary for self-assembly. © 2012 European Peptide Society and John Wiley & Sons, Ltd.


Ghosh J.,Indian Institute of Chemical Technology | Ghosh J.,CSIR - Central Electrochemical Research Institute | Bose M.,Indian Institute of Chemical Technology | Roy S.,CSIR - Central Electrochemical Research Institute | Bhattacharyya S.N.,Indian Institute of Chemical Technology
Cell Host and Microbe | Year: 2013

Leishmania donovani causes visceral leishmaniasis (VL) where the parasite infects and resides inside liver and spleen tissue macrophages. Given the abnormal lipid profile observed in VL patients, we examined the status of serum lipids in an experimental murine model of VL. The murine VL liver displayed altered expression of lipid metabolic genes, many of which are direct or indirect targets of the liver-specific microRNA-122. Concomitant reduction of miR-122 expression was observed in VL liver. High serum cholesterol caused resistance to L. donovani infection, while downregulation of miR-122 is coupled with low serum cholesterol in VL mice. Exosomes secreted by the infective parasites caused reduction in miR-122 activity in hepatic cells. Leishmania surface glycoprotein gp63, a Zn-metalloprotease, targets pre-miRNA processor Dicer1 to prevent miRNP formation in L. donovani-interacting hepatic cells. Conversely, restoration of miR-122 or Dicer1 levels in VL mouse liver increased serum cholesterol and reduced liver parasite burden. © 2013 Elsevier Inc.


Sankaranarayanan K.,CSIR - Central Electrochemical Research Institute | Sreedhar B.,Indian Institute of Chemical Technology | Nair B.U.,CSIR - Central Electrochemical Research Institute | Dhathathreyan A.,CSIR - Central Electrochemical Research Institute
Journal of Physical Chemistry B | Year: 2013

This study reports on the helix-beta conformation transition of bovine β-lactoglobulin (βLG) prepared at two different pH conditions (pH 4 and 7.5) and in the presence of the ionic liquid 1-ethyl-3-methylimidazolium ethyl sulfate (IL-emes). The investigation was carried out by combining a range of techniques such as circular dichroic (CD) spectroscopy, steady-state fluorescence spectroscopy, isothermal titration calorimetry (ITC), and transmission electron microscopy. The influence of microviscosity induced by IL-emes on the secondary structure of βLG was studied using a quartz crystal microbalance and correlated with the steady-state fluorescence emission. The effect of heat on the helix-beta transition in βLG was directly measured by ITC by titrating βLG with IL-emes. The net effect of heat after subtraction of the heat of dilution was negative in both cases, suggesting that the protein moves to a stable conformation. The changes in the overall aggregated structures were confirmed by transmission electron microscopy, where a shift in the size and morphology of aggregates was found, from large clusters (size of 70 nm) at pH 4 to smaller aggregates (size of 20 nm) at pH 7.5, which reduced to 7 nm in the presence of the IL. The transformation of helical to beta structure at pH 4 show that the folding pathway in the presence of the ionic liquid is hierarchical, whereas at neutral pH, it appeared to be nonhierarchical and the final native structure was acquired by nonlocal interactions through typical forces involved in the stabilization of the tertiary structure. © 2013 American Chemical Society.


Pawar V.K.,CSIR - Central Electrochemical Research Institute | Meher J.G.,CSIR - Central Electrochemical Research Institute | Singh Y.,CSIR - Central Electrochemical Research Institute | Chaurasia M.,Amity University | And 2 more authors.
Journal of Controlled Release | Year: 2014

Delivery of proteins/peptides to the gastrointestinal (GI) tract via peroral/oral route involves tremendous challenges due to unfavorable environmental conditions like harsh pH, presence of proteolytic enzymes and absorption barriers. Detailed research is being conducted at the academic and industrial levels to diminish these troubles and various products are under clinical trials. Several approaches have been established to optimize oral delivery of proteins and peptides and can be broadly categorized into chemical and physical strategies. Chemical strategies include site specific mutagenesis, proteinylation, glycosylation, PEGylation and prodrug approaches, whereas physical strategies comprise formulation based approaches including application of absorption enhancers and metabolism modifiers along with delivering them via colloidal carrier systems such as nanoparticles, liposomes, microparticles, and micro- and nano-emulsions. This review stands to accomplish the diverse aspects of oral delivery of proteins/peptides and summarizes the key concepts involved in targeting the biodrugs to specific sites of the GI tract such as the intestine and colon. Furthermore some light has also been shed on the current industrial practices followed in developing oral formulations of such bioactives. © 2014 Elsevier B.V.. All rights reserved.


Pradhan S.,Indian Institute of Chemical Technology | Baidya A.K.,Indian Institute of Chemical Technology | Ghosh A.,U.S. National Institutes of Health | Chowdhury R.,Indian Institute of Chemical Technology
Journal of Bacteriology | Year: 2010

Vibrio cholerae strains of the O1 serogroup that typically cause epidemic cholera can be classified into two biotypes, classical and El Tor. The El Tor biotype emerged in 1961 and subsequently displaced the classical biotype as a cause of cholera throughout the world. In this study we demonstrate that when strains of the El Tor and classical biotypes were cocultured in standard LB medium, the El Tor strains clearly had a competitive growth advantage over the classical biotype starting from the late stationary phase and could eventually take over the population. The classical biotype produces extracellular protease(s) in the stationary phase, and the amounts of amino acids and small peptides in the late stationary and death phase culture filtrates of the classical biotype were higher than those in the corresponding culture filtrates of the El Tor biotype. The El Tor biotype cells could utilize the amino acids more efficiently than the classical biotype under the alkaline pH of the stationary phase cultures but not in medium buffered to neutral pH. The growth advantage of the El Tor biotype was also observed in vivo using the ligated rabbit ileal loop and infant mouse animal models. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Chakraborty T.K.,CSIR - Central Electrochemical Research Institute | Sreekanth M.,Indian Institute of Chemical Technology | Pulukuri K.K.,CSIR - Central Electrochemical Research Institute
Tetrahedron Letters | Year: 2011

A stereoselective synthesis of the C16-C28 fragment of cytostatic C 2-symmetric macrolide rhizopodin is described. Enantioselective addition of a chiral thiazolidinethione derived titanium enolate to acetal, Evans' aldol reaction, Horner-Wadsworth-Emmons reaction, and Mukaiyama aldol reaction were applied as key steps. © 2010 Elsevier Ltd. All rights reserved.


Tyagi V.,CSIR - Central Electrochemical Research Institute | Khan S.,CSIR - Central Electrochemical Research Institute | Giri A.,CSIR - Central Electrochemical Research Institute | Gauniyal H.M.,Indian Institute of Chemical Technology | And 2 more authors.
Organic Letters | Year: 2012

A novel ligand-free palladium-catalyzed cascade reaction for the synthesis of highly diverse isoquinolin-1(2H)-one derivatives from isocyanide and amide precursors synthesized by Ugi-MCR has been developed. A broad variety of acids, amines, and isocyanides were used as starting materials for Ugi-MCR leading to various amide precursors, which in turn provided entry into diverse isoquinolin-1(2H)-one derivatives. The reaction proceeds through tandem isocyanide insertion with intramolecular cyclization followed by a Mazurciewitcz-Ganesan type sequence to provide isoquinoline-1(2H)-one derivatives in moderate to good yields. © 2012 American Chemical Society.


Sahu B.D.,Indian Institute of Chemical Technology | Kumar J.M.,CSIR - Central Electrochemical Research Institute | Sistla R.,Indian Institute of Chemical Technology
PLoS ONE | Year: 2015

Acute renal failure is a serious complication of the anticancer drug cisplatin. The potential role of baicalein, a naturally occurring bioflavonoid on cisplatin-induced renal injury is unknown. Here, we assessed the effect of baicalein against a murine model of cisplatininduced acute renal failure and investigated the underlying possible mechanisms. Renal function, kidney histology, inflammation, oxidative stress, renal mitochondrial function, proteins involved in apoptosis, nuclear translocation of Nrf2 and effects on intracellular signaling pathways such as MAPKs, and NF-κB were assessed. Pretreatment with baicalein ameliorated the cisplatin-induced renal oxidative stress, apoptosis and inflammation and improved kidney injury and function. Baicalein inhibited the cisplatin-induced expression of iNOS, TNF-α, IL-6 and mononuclear cell infiltration and concealed redox-sensitive transcription factor NF-κB activation via reduced DNA-binding activity, IκBα phosphorylation and p65 nuclear translocation in kidneys. Further studies demonstrated baicalein markedly attenuated cisplatin-induced p38 MAPK, ERK1/2 and JNK phosphorylation in kidneys. Baicalein also restored the renal antioxidants and increased the amount of total and nuclear accumulation of Nrf2 and downstream target protein, HO-1 in kidneys. Moreover, baicalein preserved mitochondrial respiratory enzyme activities and inhibited cisplatin-induced apoptosis by suppressing p53 expression, Bax/Bcl-2 imbalance, cytochrome c release and activation of caspase-9, caspase-3 and PARP. Our findings suggest that baicalein ameliorates cisplatin-induced renal damage through up-regulation of antioxidant defense mechanisms and down regulation of the MAPKs and NF-κB signaling pathways. © 2015 Sahu et al.


Bose D.,CSIR - Central Electrochemical Research Institute | Jayaraj G.,CSIR - Central Electrochemical Research Institute | Suryawanshi H.,CSIR - Central Electrochemical Research Institute | Agarwala P.,CSIR - Central Electrochemical Research Institute | And 4 more authors.
Angewandte Chemie - International Edition | Year: 2012

No dice: MicroRNAs (miRNAs) fine-tune gene expression, deregulation of which has been causally associated with a number of debilitating conditions. Streptomycin, a well-known aminoglycoside drug, binds to RNA secondary structures and is shown to inhibit miR-21 function by direct binding to its precursor, thus presumably interfering with the processing by the Dicer enzyme (see scheme). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Udawant S.P.,Indian Institute of Chemical Technology | Chakraborty T.K.,CSIR - Central Electrochemical Research Institute
Journal of Organic Chemistry | Year: 2011

Enantioselective total synthesis of mupirocin H is accomplished starting from d-glucose featuring strategic application of d-glucose derived chirality, diastereoselective Still-Barrish hydroboration, and further elaboration of carbon chain to furnish a phenyltetrazolyl sulfone intermediate, which on coupling with (2S,3S)-2-methyl-3-(triisopropylsilyloxy)butanal under Julia-Kocienski olefination conditions gave an advanced E-olefinic intermediate selectively. The E-olefin was transformed to the 4-hydroxynitrile, a prefinal substrate, which on acid-catalyzed oxidative lactonization furnished the target molecule mupirocin H in 19 steps from known compound 6 (longest linear sequence) with an overall yield of 4.96%. © 2011 American Chemical Society.


Chakraborty T.K.,CSIR - Central Electrochemical Research Institute | Pulukuri K.K.,CSIR - Central Electrochemical Research Institute | Sreekanth M.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2010

A stereoselective synthesis of the C1-C15 fragment of a G-actin binding natural macrodiolide, rhizopodin was achieved using, as key steps, highly stereoselective acetate aldol reactions to build the C1-C7 fragment, one pot oxazole synthesis and an asymmetric Keck allylation reaction to build the C8-C15 fragment and finally, a Stille reaction to couple both the fragments. © 2010 Elsevier Ltd. All rights reserved.


Sashidhara K.V.,CSIR - Central Electrochemical Research Institute | Kumar A.,CSIR - Central Electrochemical Research Institute | Agarwal S.,National Institute of Pharmaceutical Education and Research | Kumar M.,CSIR - Central Electrochemical Research Institute | And 2 more authors.
Advanced Synthesis and Catalysis | Year: 2012

An innovative and efficient approach towards diversity-oriented synthesis of 4-phenacylideneflavenes has been developed from substituted salicylaldehydes and acetophenones using iodine under solvent-free conditions. Both symmetrical and unsymmetrical functionalized 4-phenacylideneflavenes were synthesized in good to excellent yields and their mechanism of formation is discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Mishra A.K.,Indian Institute of Chemical Technology | Narayan R.,Indian Institute of Chemical Technology | Raju K.V.S.N.,Indian Institute of Chemical Technology | Aminabhavi T.M.,CSIR - Central Electrochemical Research Institute
Progress in Organic Coatings | Year: 2012

Effect of chain extender and NCO/OH ratio on the properties of hyperbranched polyurethane (HBPU)-urea and HBPU-imide coatings were examined. The NCO terminated pre-polymers were prepared by reacting the first (G1) and the second (G2) generation hyperbranched polyester polyols (HBP-G1 and HBP-G2) with excess diisocyanate. The excess NCO content of the prepolymer was reacted with different chain extenders viz., 3-aminopropyl triethoxysilane (APTES), pyromellitic dianhydride (PMDA) and N-hydroxyphthalimide (NHTM) to obtain HBPU-urea or HBPU-imide coatings. The structure-property relationships of the different coatings were investigated by FTIR peak deconvolution, and these data suggests the highest extent of hydrogen bonding interaction for PMDA-based coatings, which increases with increasing NCO/OH ratio. Film properties were evaluated by TGA, DMTA, UTM and contact angle measurements; these results were supported by FTIR deconvolution results. As per contact angle measurements, hydrophobicity of coatings increased by increasing NCO/OH ratio. The adhesive strength, abrasion resistance, alkali resistance, and gel content of the coatings were also evaluated. © 2011 Elsevier B.V. All Rights Reserved.


Rao C.R.K.,CSIR - Central Electrochemical Research Institute | Rao C.R.K.,Indian Institute of Chemical Technology
Journal of Applied Polymer Science | Year: 2012

An electrochemical method for depositing redispersible, lower size gold nanoparticles from a novel polyelectrolyte-gold complex is described. The size of gold nanoparticles is in the range 6.2-15.4 nm. The gold nanoparticles, first deposited on platinum surface are transferable into water. They can also be directly in situ-electrodeposited on to materials like carbon, carbon nanotubes or conducting polymers for an end use as electro catalysts. The composites Au-MWCNT, Pt-MWCNT, Au-Carbon, and Pt-Carbon are synthesized and tested for their electrocatalytic activity. The composites exhibit good catalytic activity in sensing dopamine or electrooxidation of methanol. Copyright © 2011 Wiley Periodicals, Inc.


Mondal G.,Indian Institute of Chemical Technology | Mondal G.,CSIR - Central Electrochemical Research Institute | Barui S.,Indian Institute of Chemical Technology | Chaudhuri A.,Indian Institute of Chemical Technology
Biomaterials | Year: 2013

Ever since the finding that αvβ3 integrin receptors are over expressed on the endothelial cell surfaces of tumor vasculatures relative to normal resting vasculatures was disclosed in 1994, αvβ3 integrin receptor selective systems are finding increasing applications both for targeting anti-cancer drugs/genes selectively to tumor vasculatures and for imaging growing tumors. Among the cyclic peptide based integrin antagonists identified through both phage display and structure-activity studies, mainly αvβ3 integrin selective cyclic peptide c(RGDfK-) has found most widespread exploitations for targeting chemotherapeutic drugs/genes to both tumor and tumor vasculatures in anti-angiogenic cancer therapy. Herein we show that a lipopeptide containing widely acclaimed αvβ3 integrin receptor selective cyclic RGDfK ligand in its head-group area can effectively deliver genes into both the endothelial and tumor cells via all the three widely used integrin receptors namely αvβ3, αvβ5 & α5β1 integrins. We demonstrate that intravenous administration of the electrostatic complex of the cationic liposomes of an amphiphiles with cyclic RGDfK head-group and the anti-cancer p53 gene leads to significant tumor growth inhibition in a syngeneic mouse tumor model presumably through inducing apoptosis of tumor neovasculatures. The findings delineated herein provide experimental evidence that cyclic-RGDfK-ligand may not be that highly selective for αvβ3 integrin receptor as is popularly believed. © 2013 Elsevier Ltd.


Rao K.N.,Indian Institute of Chemical Technology | Rao K.N.,Inha University | Reddy B.M.,Indian Institute of Chemical Technology | Park S.-E.,Inha University
Applied Catalysis B: Environmental | Year: 2010

The influence of ceria on structural and catalytic properties of TiO2-ZrO2 mixed oxide was investigated for oxidative dehydrogenation (ODH) of p-diethylbenzene (DEB) to p-divinylbenzene (DVB) utilizing CO2 as soft oxidant. The investigated catalysts were synthesized by coprecipitation and impregnation methods involving microwave treatment. Catalyst characterization was achieved using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), BET surface area and temperature programmed desorption/oxidation (TPD/TPO) methods. The XRD and TEM results revealed that the prepared samples are in nanocrystalline form with 10-20nm size. The presence of acid-base sites and their distribution was examined by NH3 and CO2 TPD measurements. The ceria promoted sample exhibited more number of acid sites. The TPO measurements revealed that CO2 dissociates over the reduced surface of the catalysts. Among various catalysts investigated, the microwave treated CeO2/TiO2-ZrO2 sample exhibited better conversion and a high product selectivity. The time-on-stream studies revealed that ceria promoted TiO2-ZrO2 catalysts exhibit higher stability for ODH of DEB. © 2010 Elsevier B.V.


Agarwal T.,CSIR - Central Electrochemical Research Institute | Roy S.,Indian Institute of Chemical Technology | Chakraborty T.K.,Indian Institute of Chemical Technology | Chakraborty T.K.,CSIR - Central Electrochemical Research Institute | Maiti S.,CSIR - Central Electrochemical Research Institute
Biochemistry | Year: 2010

Quadruplex-specific molecules can serve as suitable drugs in cancer therapy. We have synthesized a pair of furan-based cyclic homooligopeptides, ligand 1 and ligand 2, to specifically target G-quadruplexes. We have shown by CD spectroscopy and UV melting that these ligands can effectively induce G-quadruplex structures in the G-rich 22-mer c-MYC DNA sequence and further stabilize the structure. Equilibrium binding constants measured by isothermal titration calorimeter methods indicate a high affinity of the ligands for the quadruplex structures (K ∼ 107 M-1) and no affinity for the duplex DNA, demonstrating that these ligands are selective for G-quadruplex structures. Surface plasmon resonance was also used to compute the binding while fluorescence resonance energy transfer-based assay was additionally used to confirm the selectivity. Moreover, using real time PCR we observed up to 90% downregulation of c-MYC transcripts after 24 h of ligand treatment in HeLa cells. Using a luciferase assay we show the downregulation of the protein levels. Fluorescent-assisted cell sorter-based cell cycle analysis showed a prominent arrest of cells in the sub-G1 stage upon treatment of ligands that leads toward apoptosis. Altogether, these experiments support the hypothesis that the present molecules are effective in specifically binding and stabilizing quadruplexes and provide a suitable scaffold to develop into a quadruplex-targeting therapeutic agent. © 2010 American Chemical Society.


Cao J.-T.,Nanjing University | Zhu Y.-D.,Nanjing University | Rana R.K.,Indian Institute of Chemical Technology | Zhu J.-J.,Nanjing University
Biosensors and Bioelectronics | Year: 2014

A novel microfluidic platform integrated with a flexible PDMS-based electrochemical cytosensor was developed for real-time monitoring of the proliferation and apoptosis of HeLa cells. The PDMS-gold film, which had a conductive smooth surface and was semi-transparent, facilitated electrochemical measurements and optical microscope observations. We observed distinct increases and decreases in peak current intensity, corresponding to cell proliferation in culture medium and apoptosis in the presence of an anticancer drug, respectively. This electrochemical analysis method permitted real-time, label-free monitoring of cell behavior, and the electrochemical results were confirmed with optical microscopy. The flexible microfluidic electrochemical platform presented here is suitable for on-site monitoring of cell behavior in microenvironments. © 2013.


Kushwaha S.,M. S. University of Baroda | Sreedhar B.,Indian Institute of Chemical Technology | Padmaja P.,M. S. University of Baroda
Langmuir | Year: 2012

Palm shell-based adsorbents prepared under five different thermochemical conditions and palm shell powder have been shown to be quite effective for removal of uranium from aqueous solutions. X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS), and Fourier transform infrared spectroscopy (FTIR) have been used to determine information about the speciation and binding of uranium on the adsorbents under study. Studies indicate that the uranium which is present as uranyl ion in aqueous solution is present in mixed valence states (U(IV), U(V), and U(VI)) when it is bound to the adsorbents. The mechanism of adsorption is likely to be adsorption-coupled reduction as well as complexation. Adsorption of uranium, cesium, and iron was found to be quantitative in binary as well as ternary mixtures. © 2012 American Chemical Society.


Sahu B.D.,Indian Institute of Chemical Technology | Putcha U.K.,National Institute of Nutrition | Kuncha M.,Indian Institute of Chemical Technology | Rachamalla S.S.,Osmania University | Sistla R.,Indian Institute of Chemical Technology
Molecular and Cellular Biochemistry | Year: 2014

Carnosic acid is a well-known antioxidant. Recently, it has been identified as modulator of nuclear factor erythroid 2-related factor 2 (Nrf2). The effect of carnosic acid in the context of cardiovascular disorders has not been studied. In the present study, we investigated the beneficial effect and the underlying cardioprotective mechanism of carnosic acid by using mouse model of isoproterenol (ISO)-induced myocardial stress. Elevated serum levels of Troponin I, CK-MB, LDH, SGOT and SGPT, and myofibrillar degeneration with necrotic damage, and the presence of epicardial inflammatory infiltrate (H & E staining) confirmed the ISO-induced myocardial stress. Myocardial content of vitamin C, reduced glutathione, glutathione peroxidase, glutathione reductase, glutathione S-transferase, NAD(P)H: quinine oxidoreductase 1, superoxide dismutase, catalase, nuclear translocation of Nrf2 and protein expression heme oxygenase-1 were evaluated. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and myocardial expression of cleaved caspase-3, caspase-9, p53, Bax, and Bcl-2 were investigated to assess the apoptotic cell death. Pretreatment with carnosic acid attenuated ISO-induced elevated serum levels of Troponin I, CK-MB, LDH, SGOT and SGPT, and histopathological alterations in heart. Moreover, carnosic acid enhanced the nuclear translocation of Nrf2 and up-regulated the phase II/antioxidant enzyme activities. Furthermore, TUNEL assay and apoptosis-related protein analysis indicated that carnosic acid prevented ISO-induced cardiomyocyte apoptosis. Isoproterenol-induced myocardial lipid peroxidation and protein oxidation were also significantly decreased by carnosic acid pretreatment. The overall results clearly indicate that therapeutic application of carnosic acid might be beneficial in treating cardiovascular disorders. © 2014, Springer Science+Business Media New York.


Vellakkaran M.,Indian Institute of Chemical Technology | Andappan M.M.S.,Biocon | Kommu N.,Indian Institute of Chemical Technology
European Journal of Organic Chemistry | Year: 2012

By employing ligands in the Pd II-mediated arylative isomerization of allyl alcohols, a milder and regioselective access to the versatile building blocks β-aryl aldehydes and ketones was developed. This new and chelation-controlled protocol enabled the compatibility of wide range of functionalities to generate dihydrochalcones, α-benzyl-α′- alkyl acetones, dihydrocinnamaldehydes, and α-benzyl β-keto esters (from Baylis-Hillman adducts). A practical multigram synthesis of an intermediate for Propafenone was also demonstrated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Datta S.,Barasat Government College | Roy S.,Indian Institute of Chemical Technology | Manna M.,Barasat Government College
Brazilian Journal of Infectious Diseases | Year: 2015

Background: Visceral leishmaniasis (VL) or Kala-Azar (KA) is one of the most deadly forms of disease among all neglected tropical diseases. There are no satisfactory drugs or vaccine candidates available for this dreaded disease. Our previous studies showed promising therapeutic and prophylactic efficacy of the live, radio-attenuated parasites through intramuscular (I.M.) and intraperitoneal (I.P.) route in BALB/c mice model. Methods: The T-cell proliferation level, the mRNA expression level of inducible nitric oxide synthase (iNOS) and tumor growth factor-beta (TGF-β) genes and finally the phosphorylation levels of phosphoinositide dependent kinase 1 (PDK1), phosphoinositide 3 kinase (PI3K) and p38 mitogen activated protein kinase (p38MAPK) molecules were checked in BALB/c mice model immunized with radio-attenuated Leishmania donovani parasites through I.M. route. Results: Higher T-cell proliferation, increased iNOS level, and suppressed TGF-β level were found in treated infected animal groups (100 and 150. Gy) in relation to untreated infected animals. Likewise, phosphorylation levels of PDK1, PI3K and p38MAPK of these two groups were increased when compared to untreated infected controls. Conclusion: The clearance of the parasites from treated infected groups of animals may be mediated by the restoration of T-cell due to therapy with radio-attenuated L. donovani parasites. The killing of parasites was mediated by increase in nitric oxide release through PDK1, PI3K and p38MAPK signaling pathways. A lower TGF-β expression has augmented the restored Th1 ambience in the 100 and 150. Gy treated animal groups proving further the efficacy of the candidate vaccine. © 2015.


Deme P.,Indian Institute of Chemical Technology | Azmeera T.,Indian Institute of Chemical Technology | Prabhavathi Devi B.L.A.,Indian Institute of Chemical Technology | Jonnalagadda P.R.,National Institute of Nutrition | And 2 more authors.
Food Chemistry | Year: 2014

An improved sample preparation using dispersive solid-phase extraction clean-up was proposed for the trace level determination of 35 multiclass pesticide residues (organochlorine, organophosphorus and synthetic pyrethroids) in edible oils. Quantification of the analytes was carried out by gas chromatography-mass spectrometry in negative chemical ionisation mode (GC-NCI-MS/MS). The limit of detection and limit of quantification of residues were in the range of 0.01-1 ng/g and 0.05-2 ng/g, respectively. The analytes showed recoveries between 62% and 110%, and the matrix effect was observed to be less than 25% for most of the pesticides. Crude edible oil samples showed endosulfan isomers, p,p′-DDD, acypermethrin, chlorpyrifos, and diazinon residues in the range of 0.56-2.14 ng/g. However, no pesticide residues in the detection range of the method were observed in refined oils. © 2013 Elsevier Ltd. All rights reserved.


Yang G.,Nanjing University | Li Y.,Nanjing University | Rana R.K.,Indian Institute of Chemical Technology | Zhu J.-J.,Nanjing University
Journal of Materials Chemistry A | Year: 2013

A facile in situ assembly strategy was developed for the fabrication of Pt-Au alloy nanoparticles (NPs) on nitrogen-doped graphene (N-G) sheets, and the as-fabricated Pt-Au/N-G nanocomposites were suitable for electrochemical applications. As characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction analysis and inductively coupled plasma-atomic emission spectroscopy techniques, Pt-Au alloy NPs with an average size of 4-5 nm were uniformly distributed on the N-G surface through intrinsic covalent bonds. The Pt-Au/N-G nanocomposites exhibited excellent electrocatalytic activity and stability towards the methanol oxidation reaction with the highest capability observed for a Pt/Au atomic ratio of 3/1. The unique electrochemical features are distinctive from those of N-free nanocomposites and commercially available Pt/C catalysts, indicative of the alloying effect of Pt-Au and their synergistic interaction with the N-G sheet, which may open up new possibilities for the preparation of N-G-based nanocomposites for other intensive applications as well. © 2013 The Royal Society of Chemistry.


Pushpavalli S.N.C.V.L.,Functional Genomics and Gene Silencing Group | Bag I.,Indian Institute of Chemical Technology | Pal-Bhadra M.,Indian Institute of Chemical Technology | Bhadra U.,Functional Genomics and Gene Silencing Group
Chromosome Research | Year: 2012

Argonaute-1 (Ago-1) plays a crucial role in gene regulation and genome stability via biogenesis of small non-coding RNAs. Two "Argonaute" family genes, piwi and Ago-2 in Drosophila are involved in multiple silencing mechanisms in the nucleus, transgene cosuppression, long-distant chromosome interaction, nuclear organization and heterochromatin formation. To investigate whether Ago-1 also plays a similar role, we have generated a series of Ago-1 mutations by excising P element, inserted in the Ago-1 promoter (Ago-1 k08121). AGO-1 protein is distributed uniformly in the nucleus and cytosol in early embryos but accumulated predominantly in the cytoplasm during the gastrulation stage. Repeat induced silencing produced by the mini-white (mw) array and transcriptional cosuppression of non-homologous transgenes Adh-w/w- Adh was disrupted by Ago-1 mutation. These effects of Ago-1 are distict from its role in microRNA processing because Dicer-1, a critical enzyme for miRNA biogenesis, has no role on the above silencing. Reduction of AGO-1 protein dislodged the POLYCOMB, EZ (enhancer of zeste) and H3me3K27 binding at the cosuppressed Adh-w transgene insertion sites suggesting its role in Polycomb dependent cosuppression. An overall reduction of methylated histone H3me2K9 and H3me3K27 from the polytene nuclei precisely from the mw promoters was also found that leads to concomitant changes in the chromatin structure. These results suggest a prominent role of Ago-1 in chromatin organization and transgene silencing and demonstrate a critical link between transcriptional transgene cosuppression, heterochromatin formation and chromatin organization. We propose Drosophila Ago-1 as a multifunctional RNAi component that interconnects at least two unrelated events, chromatin organization in the nucleus and microRNA processing in the cytoplasm, which may be extended to the other systems. © 2012 Springer Science+Business Media B.V.


Roychoudhury J.,Indian Institute of Chemical Technology | Roychoudhury J.,University of Washington | Sinha R.,Indian Institute of Chemical Technology | Ali N.,Indian Institute of Chemical Technology
PLoS ONE | Year: 2011

Background: Resistance of Leishmania donovani to pentavalent antimonials, the first-line treatment of visceral leishmaniasis (VL), has become a critical issue worldwide. Second-line and new drugs are also not devoid of limitations. Suitable drug-delivery systems can improve the mode of administration and action of the existing antimonials, thus increasing their clinical life. Methodology/Principal Findings: We investigated the efficacy of sodium stibogluconate (SSG) in phosphatidylcholine (PC)-stearylamine-bearing liposomes (PC-SA-SSG), PC-cholesterol liposomes (PC-Chol-SSG) and free amphotericin B (AmB) against SSG-resistant L. donovani strains in 8-wk infected BALB/c mice. Animals were sacrificed and parasites in liver, spleen and bone marrow were estimated 4-wk post-treatment by microscopic examination of stamp smears and limiting dilution assay. A set of PC-SA-SSG and AmB treated mice were further studied for protection against reinfection. Serum antibodies and cytokine profiles of ex-vivo cultured splenocytes were determined by ELISA. Uptake of free and liposomal SSG in intracellular amastigotes was determined by atomic absorption spectroscopy. Rhodamine 123 and 5-carboxyfluorescein, known substrates of Pgp and MRP transporter proteins, respectively, were used in free and liposomal forms for efflux studies to estimate intracellular drug retention. Unlike free and PC-Chol-SSG, PC-SA-SSG was effective in curing mice infected with two differentially originated SSG-unresponsive parasite strains at significantly higher levels than AmB. Successful therapy correlated with complete suppression of disease-promoting IL-10 and TGF-β, upregulation of Th1 cytokines and expression of macrophage microbicidal NO. Cure due to elevated accumulation of SSG in intracellular parasites, irrespective of SSG-resistance, occurs as a result of increased drug retention and improved therapy when administered as PC-SA-SSG versus free SSG. Conclusions/Significance: The design of this single-dose combination therapy with PC-SA-SSG for VL, having reduced toxicity and long-term efficacy, irrespective of SSG-sensitivity may prove promising, not only to overcome SSG-resistance in Leishmania, but also for drugs with similar resistance-related problems in other diseases. © 2011 Roychoudhury et al.


Kushwaha S.,M. S. University of Baroda | Sreedhar B.,Indian Institute of Chemical Technology | Sudhakar P.P.,M. S. University of Baroda
Bioresource Technology | Year: 2012

Palm shell based adsorbents prepared under five different thermochemical conditions have been shown to be quite effective for removal of chromium (III and VI) from aqueous solutions. X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FT-IR) have been used to determine information about the speciation and binding of chromium on the adsorbents under study. X-ray photoelectron spectroscopy (XPS) studies indicate that oxidation of lignin moieties takes place concurrently to Cr(VI) reduction and leads to the formation of hydroxyl and carboxyl functions. The maximum adsorption capacity for hexavalent chromium was found to be about 313. mg/g in an acidic medium using PAPSP. This is comparable to other natural substrates and ordinary adsorbents. The efficacy of the adsorbents under study to remove chromium from plating waste water has been demonstrated. © 2012 Elsevier Ltd.


Vellakkaran M.,Indian Institute of Chemical Technology | Andappan M.M.S.,Biocon | Kommu N.,Indian Institute of Chemical Technology
Green Chemistry | Year: 2014

Air was employed as a green reoxidant of Pd(0), replacing stoichiometric and toxic silver salt, in the chelation-controlled Pd(II)-modulated arylative enolization of prop-2-en-1-ols to acquire synthetically-important β-aryl carbonyl derivatives. This green approach, which didn't require acid or base, allowed the compatibility of a range of functionalities (inclusive of -I, -Br & -Cl), resulting in the construction of structurally-diverse dihydrochalcones, α-benzyl-α′-alkyl acetones, α-benzyl β-keto esters and dihydrocinnamaldehydes. In addition to organoboronic acids, efficient coupling was also achieved with boronic esters and trifluoroborate salts. A deuterium labelling experiment revealed an interesting 1,2-hydrogen shift after β-arylation in the catalytic process. © the Partner Organisations 2014.


Bhowmick S.K.,Indian Institute of Chemical Technology | Ghosh D.,Dinabandhu Andrews College | Dana S.K.,Indian Institute of Chemical Technology
Chaos | Year: 2011

An oscillatory system can have opposite senses of rotation, clockwise or anticlockwise. We present a general mathematical description of how to obtain counter-rotating oscillators from the definition of a dynamical system. A type of mixed synchronization emerges in counter-rotating oscillators under diffusive scalar coupling when complete synchronization and antisynchronization coexist in different state variables. We present numerical examples of limit cycle van der Pol oscillator and chaotic Rössler and Lorenz systems. Stability conditions of mixed synchronization are analytically obtained for both Rössler and Lorenz systems. Experimental evidences of counter-rotating limit cycle and chaotic oscillators and mixed synchronization are given in electronic circuits. © 2011 American Institute of Physics.


Kumar G.S.,Indian Institute of Chemical Technology | Pieber B.,Christian Doppler Laboratory | Reddy K.R.,Indian Institute of Chemical Technology | Kappe C.O.,Christian Doppler Laboratory
Chemistry - A European Journal | Year: 2012

Peroxides and ethers in flow: 2-Carbonyl-substituted phenols and β-ketoesters react safely with ethers in a microreactor environment using a copper catalyst and an organic peroxide (TBHP). This protocol results in unsymmetrical acetal scaffolds not easily available otherwise (see scheme). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Roy A.S.,R K Mission Residential College | Saha P.,R K Mission Residential College | Adhikary N.D.,Indian Institute of Chemical Technology | Ghosh P.,R K Mission Residential College
Inorganic Chemistry | Year: 2011

The diamagnetic VO2+-iminobenzosemiquinonate anion radical (LR IS •-, R = H, Me) complexes, (L -)(VO2+)(LR IS •-): (L1 -)(VO2+)(LH IS •-)•3/2MeOH (1•3/2MeOH), (L2 -)(VO2+)(LH IS •-)(2), and (L2 -)(VO2+)(LMe IS •-)•1/2 LMe AP (3•1/2 LMe AP), incorporating tridentate monoanionic NNO-donor ligands {L = L1 or L2,L1H = (2-[(phenylpyridin-2-yl-methylene)amino]phenol; L2H = 1-(2-pyridylazo)-2-naphthol; LH IS •- = o-iminobenzosemiquinonate anion radical; LMe IS •- = o-imino-p-methylbenzosemiquinonate anion radical; and LMe AP = o-amino-p-methylphenol} have been isolated and characterized by elemental analyses, IR, mass, NMR, and UV-vis spectra, including the single-crystal X-ray structure determinations of 1•3/2MeOH and 3•1/2 LMe AP. Complexes 1•3/2MeOH, 2, and 3•1/2 LMe AP absorb strongly in the visible region because of intraligand (IL) and ligand-to-metal charge transfers (LMCT). 1•3/2MeOH is luminescent (λext, 333 nm; λem, 522, 553 nm) in frozen dichloromethane-toluene glass at 77 K due to πdiimine → πdiimins * transition. The V-Ophenolato (cis to the V=O) lengths, 1.940(2) and 1.984(2) Å, respectively, in 1•3/2MeOH and 3•1/2 LMe AP are consistent with the VO2+ description. The V-Oiminosemiquinonate (trans to the V=O) lengths, 2.1324(19) in 1•3/2MeOH and 2.083(2) Å in 3•1/2 LMe AP AP, are expectedly ∼0.20 Å longer due to the trans influence of the V=O bond. Because of the stronger affinity of the paramagnetic VO2+ ion to the LH IS •- or LMe IS •-, the V-Niminosemiquinonate lengths, 1.908(2) and 1.921(2) Å, respectively, in 1•3/2MeOH and 3•1/2 LMe AP, are unexpectedly shorter. Density functional theory (DFT) calculations using B3LYP, B3PW91, and PBE1PBE functionals on 1 and 2 have established that the closed shell singlet (CSS) solutions (VO3+-amidophenolato (L R AP 2-) coordination) of these complexes are unstable with respect to triplet perturbations. But BS (1,1) Ms = 0 (VO2+-iminobenzosemiquinonate anion radical (LR IS •-) coordination) solutions of these species are stable and reproduce the experimental bond parameters well. Spin density distributions of one electron oxidized cations are consistent with the [(L -)(VO2+)(LR IQ)]+ descript ions [VO2+-o-iminobenzoquinone (LR IQ) coordination], and one electron reduced anions are consistent with the [(L •2-)(VO3+)(LR AP 2-)]- descriptions [VO3+-amidophenolato (L R AP 2-) coordination], incorporating the diimine anion radical (L1 •2-) or azo anion radical (L 2 3-). Although, cations and anions are not isolable, but electro-and spectro-electrochemical experiments have shown that 3+ and 3- ions are more stable than 1+, 2+ and 1-, 2- ions. In all cases, the reductions occur with simultaneous two electron transfer, may be due to formation of coupled diimine/azo anion radical-VO2+ species as in [(L•2-) (VO2+)(LR AP 2-)]2-. © 2011 American Chemical Society.


Yang G.,Nanjing University | Li L.,Nanjing University | Rana R.K.,Indian Institute of Chemical Technology | Zhu J.-J.,Nanjing University
Carbon | Year: 2013

A new electrochemical immunosensor was developed for ultrasensitive detection of matrix metalloproteinase-2 (MMP-2), which is one of the key biomarkers in blood. In our approach, an effective assembly of well-defined gold nanoparticles on nitrogen-doped graphene sheets was demonstrated. The composite facilitated robust immobilization of antibodies, promoted electron transfer and exhibited excellent electrochemical activity, which are suitable for biosensing. The design of the immunosensor also involved a polydopamine functionalized graphene oxide hybrid conjugated to horseradish peroxidase-secondary antibodies by covalent bonds as a multi-labeled and biocompatible probe to increase the electrochemical response. This novel signal amplification strategy with a sandwich-type immunoreaction significantly enhanced the sensitivity of detection of biomarkers. The proposed immunosensor displayed excellent analytical performance in the detection of MMP-2 ranging from 0.0005 to 50 ng mL-1, with a detection limit of 0.11 pg mL -1. Furthermore, it not only exhibited good stability with adequate reproducibility and accuracy, but also demonstrated efficiency in the detection of MMP-2 in real samples. © 2013 Elsevier Ltd. All rights reserved.


Yang G.,Nanjing University | Cao J.,Nanjing University | Li L.,Nanjing University | Rana R.K.,Indian Institute of Chemical Technology | Zhu J.-J.,Nanjing University
Carbon | Year: 2013

Here we demonstrate the fabrication of an effective cytosensor using carboxymethyl chitosan-functionalized graphene (CMC-G) prepared through chemical reduction of graphene oxide. The CMC-G hybrid was further characterized with UV-vis spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, transmission electron microscopy and atomic force microscopy. Layer-by-layer assembly of CMC-G with polyethyleneimine and folic acid enabled the fabrication of a label-free electrochemical impedance spectroscopy cytosensor with high stability and biocompatibility. The proposed cytosensor exhibited good electrochemical behavior and cell-capture ability for HL-60 cells, and showed a wide linear range and low detection limit for quantification. © 2012 Published by Elsevier Ltd.


Patent
Indian Institute of Chemical Technology and Colgate Palmolive | Date: 2010-02-25

A method is described for producing magnolol, or a derivative or analogue thereof. The method includes obtaining MOM ether of 5,5-diallylbiphenyl-2,2-diol or a derivative or analogue thereof and subsequently converting the MOM ether of 5,5-diallylbiphenyl-2,2-diol into magnolol or a derivative or analogue thereof.


Reddy N.S.S.,Indian Institute of Chemical Technology | Reddy N.S.S.,Adikavi Nannaya University | Reddy B.J.M.,Adikavi Nannaya University | Reddy B.V.S.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

A novel strategy has been developed for the syntheses of (-)-crispine, (-)-benzo[a]quinolizidine, and (-)-salsolidine using (R)-tert-butanesulfinamide as a source of chirality. The approach involves the stereoselective addition of Grignard reagent to chiral N-sulfinyl imine followed by cyclization of the secondary amide with a tethered halide as key steps. © 2013 Elsevier Ltd. All rights reserved.


Singh S.P.,Indian Institute of Chemical Technology | Kumar C.P.,Indian Institute of Chemical Technology | Sharma G.D.,R and nter for Engineering and Science | Kurchania R.,Maulana Azad National Institute of Technology | Roy M.S.,Defence Laboratory
Advanced Functional Materials | Year: 2012

A simple and effective modification of phenyl-C 70-butyric acid methyl ester (PC 70BM) is carried out in a single step after which the material is used as electron acceptor for bulk heterojunction polymer solar cells (PSCs). The modified PC 70BM, namely CN-PC 70BM, showed broader and stronger absorption in the visible region (350-550 nm) of the solar spectrum than PC 70BM because of the presence of a cyanovinylene 4-nitrophenyl segment. The lowest unoccupied molecular energy level (LUMO) of CN-PC 70BM is higher than that of PC 70BM by 0.15 eV. The PSC based on the blend (cast from tetrahydrofuran (THF) solution) consists of P3HT as the electron donor and CN-PC 70BM as the electron acceptor and shows a power conversion efficiency (PCE) of 4.88%, which is higher than that of devices based on PC 70BM as the electron acceptor (3.23%). The higher PCE of the solar cell based on P3HT:CN-PC 70BM is related to the increase in both the short circuit current (J sc) and the open circuit voltage (V oc). The increase in J sc is related to the stronger light absorption of CN-PC 70BM in the visible region of the solar spectrum as compared to that of PC 70BM. In other words, more excitons are generated in the bulk heterojunction (BHJ) active layer. On the other hand, the higher difference between the LUMO of CN-PC 70BM and the HOMO of P3HT causes an enhancement in the V oc. The addition of 2% (v/v) 1-chloronapthalene (CN) to the THF solvent during film deposition results in an overall improvement of the PCE up to 5.83%. This improvement in PCE can be attributed to the enhanced crystallinity of the blend (particularly of P3HT) and more balanced charge transport in the device. The photovoltaic properties of a bulk heterojunction based on poly(3- hexylthiophene) (P3HT):modified phenyl-C 70-butyric acid methyl ester (PC 70BM), a CN-PC 70BM blend, are studied. Polymer solar cells based on this blend demonstrate power conversion efficiencies of 5.8% with high open circuit voltages of 0.80 and short circuit current densities of 11.75 mA cm -2. These devices benefit from the high lowest unoccupied molecular orbital (LUMO) energy level of CN-PC 70BM and a more balanced charge transport. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Kantevari S.,Mount Sinai School of Medicine | Kantevari S.,Indian Institute of Chemical Technology | Gordon G.R.J.,University of British Columbia | MacVicar B.A.,University of British Columbia | Ellis-Davies G.C.R.,Mount Sinai School of Medicine
Nature Protocols | Year: 2011

This protocol describes a method for efficient chemical synthesis of an analog of inositol-1,4,5-trisphosphate (IP 3) hexakis acetoxymethyl ester having an ortho-nitroveratryl photochemical caging group on the 6-hydroxyl position. The six esters render the probe membrane permeant, such that it can be loaded into intact living cells in vitro or in vivo. Inside cells, the caged IP 3 is inert until activated by two-photon excitation at 720 nm. The photoliberated signaling molecule can mobilize release of Ca 2+ from intracellular stores on the endoplasmic reticulum. When co-loaded with the fluorescent Ca 2+ indicator rhod-2, one laser can be used for stimulating and monitoring intracellular Ca 2+ signaling with single-cell resolution. This protocol has chemistry and biology sections; the former describes the organic synthesis of the caged IP 3, which requires 12 d, and the latter an application to a day-long study of astrocyte-regulated neuronal function in living brain slices acutely isolated from rats. As Ca 2+ is the single most important intracellular second messenger and the IP 3-Ca 2+ signaling cascade is used by many cells to produce increases in Ca 2+ concentration, this method should be widely applicable for the study of a variety of physiological processes in intact biological systems. © 2011 Nature America, Inc. All rights reserved.


Kumar S.,National Institute of Technology Warangal | Baruah A.,Indian Institute of Technology Delhi | Tonda S.,National Institute of Technology Warangal | Kumar B.,Indian Institute of Technology Delhi | And 2 more authors.
Nanoscale | Year: 2014

N-doped ZnO/g-C3N4 hybrid core-shell nanoplates have been successfully prepared via a facile, cost-effective and eco-friendly ultrasonic dispersion method for the first time. HRTEM studies confirm the formation of the N-doped ZnO/g-C3N4 hybrid core-shell nanoplates with an average diameter of 50 nm and the g-C3N 4 shell thickness can be tuned by varying the content of loaded g-C3N4. The direct contact of the N-doped ZnO surface and g-C3N4 shell without any adhesive interlayer introduced a new carbon energy level in the N-doped ZnO band gap and thereby effectively lowered the band gap energy. Consequently, the as-prepared hybrid core-shell nanoplates showed a greatly enhanced visible-light photocatalysis for the degradation of Rhodamine B compare to that of pure N-doped ZnO surface and g-C3N4. Based on the experimental results, a proposed mechanism for the N-doped ZnO/g-C3N4 photocatalyst was discussed. Interestingly, the hybrid core-shell nanoplates possess high photostability. The improved photocatalytic performance is due to a synergistic effect at the interface of the N-doped ZnO and g-C3N4 including large surface-exposure area, energy band structure and enhanced charge-separation properties. Significantly, the enhanced performance also demonstrates the importance of evaluating new core-shell composite photocatalysts with g-C3N4 as shell material. © 2014 the Partner Organisations.


Layek K.,Indian Institute of Chemical Technology | Maheswaran H.,Indian Institute of Chemical Technology | Arundhathi R.,Indian Institute of Chemical Technology | Kantam M.L.,Indian Institute of Chemical Technology | Bhargava S.K.,RMIT University
Advanced Synthesis and Catalysis | Year: 2011

Nanocrystalline magnesium oxide-stabilized palladium(0) [NAP-Mg-Pd(0)], as an efficient catalytic system has been employed for the selective oxidation of alcohols using atmospheric oxygen as a green oxidant at room temperature. Various alcohols could be transformed into their corresponding aldehydes or ketones in good to excellent yields using a set of optimal conditions. NanoActive™ Magnesium Oxide Plus, [NAP-MgO] with its three-dimensional structure and well-defined shape acts as an excellent support for well dispersed palladium(0) nanoparticles. This catalyst can be recovered and reused for several cycles without any significant loss of catalytic activity. © 2011 Wiley-VCH Verlag GmbH & Co. KGaA.


Chintareddy V.R.,Iowa State University | Kantam M.L.,Indian Institute of Chemical Technology
Catalysis Surveys from Asia | Year: 2011

Nanocrystalline metal oxides, MgO, CuO, ZnO, TiO2 as catalysts or catalyst supports have been received much attention in the recent years, especially nanocrystalline magnesium oxide (NAP-MgO) has been used as a recyclable catalyst for Wittig, Wadsworth-Emmons, aza-Michael, Baylis-Hillman, Strecker, Aldol, Claisen-Schmidt condensation and other useful organic reactions. In general, it is reported that nanocrystalline magnesium oxide shows better activity in many organic reactions. These high reactivities are due to high surface areas combined with unusually reactive morphologies. The nanomaterials were also explored as supports to make supported metal catalysts for the organic reactions. The higher activity of these catalysts was studied partly to understand the mechanism of the reaction, the putative reaction pathways were preliminarily presented with the help of spectroscopic support, XPS, silicon, and phosphorus NMR spectroscopy. The catalysts are recovered and reused for several cycles. These catalytic systems are expected to contribute to the development of benign chemical processes. © 2011 Springer Science+Business Media, LLC.


Sharma G.D.,R and nter for Engineering and Science | Roy M.S.,Defence Laboratory | Singh S.P.,Indian Institute of Chemical Technology
Journal of Materials Chemistry | Year: 2012

We have used a stepwise approach for cosensitization of a thiocyanate-free Ru(ii) sensitizer with an organic dye (TDPP) for dye sensitized solar cells. The cosensitized SPS-01 + TDPP device showed enhanced V oc and J sc relative to the individual dye sensitized solar cells. Upon the optimization, the device made of SPS-01 + TDPP dye yielded J sc = 13.7 mA cm -2, V oc = 0.70 V, FF = 0.72 and power conversion efficiency (PCE) = 6.90%. This performance is superior to that of either individual DSSC made from SPS-01 (PCE = 5.47%) and TDPP (PCE = 4.82%), fabricated under the same conditions. This journal is © The Royal Society of Chemistry.


Mahammadunnisa Sk.,Indian Institute of Technology Hyderabad | Manoj Kumar Reddy P.,Indian Institute of Technology Hyderabad | Lingaiah N.,Indian Institute of Chemical Technology | Subrahmanyam Ch.,Indian Institute of Technology Hyderabad
Catalysis Science and Technology | Year: 2013

A series of NiO/CeO2 catalysts were prepared by using the combustion method and characterized by using XRD, N2-physisorption, TEM, UV-visible, Raman, XPS, ICP-OES and H2-TPR. Typical results indicated the NiO/CeO2 had a better performance than CeO2 for CO oxidation and 15 wt% NiO/CeO2 is active and stable, whereas catalysts with a higher NiO content of 20 and 30 wt% deactivated at 130 °C onwards. The high activity and excellent stability of 15% NiO/CeO2 catalysts can be ascribed to their high oxygen vacancy, high dispersion of NiO and strong metal-support interaction that leads to synergy between NiO and CeO2. © 2013 The Royal Society of Chemistry.


Rohit M.V.,Indian Institute of Chemical Technology | Mohan S.V.,Academy for Scientific and Industrial Research AcSIR
Renewable Energy | Year: 2016

Mixotrophic and heterotrophic cultivation modes were studied for enhancing the biomass and lipid productivities using light and carbon as critical factors. The adaptability of the newly isolated Chlorella sp towards transition from mixotrophic to heterotrophic cultivation mode was evaluated. Organic carbon illustrated higher affinity towards both biomass and lipid productivities. Specific changes in fatty acid profile were observed with respect to trophic condition. Maximum biomass productivity (4.21 g/l) and relatively higher lipid productivity (107.3 g/kg of DCW) was observed with mixotrophic (MXG) condition while heterotrophic mode showed higher lipid content (28.9%). Higher carbohydrate content (94.3 mg/g DCW) was observed in mixotrophic mode and maximum protein content (450 mg/g DCW) was obtained with heterotrophic condition. The synergism between total lipid content, fatty acid composition and biomass productivities during trophic transition was critically evaluated. The transition between the trophic modes have given deeper insights into the metabolic partitioning of carbon in photosynthetic and respiratory pathways during synthesis of biodiesel precursors. Mining of bio-based products from microalgae can create more sustainable economies and integrated approach will add paybacks to process signifying algal based biorefinery model. © 2016 Elsevier Ltd.


Srinivas M.,Indian Institute of Chemical Technology | Srinivasu P.,Indian Institute of Chemical Technology | Bhargava S.K.,Indian Institute of Chemical Technology | Bhargava S.K.,RMIT University | Kantam M.L.,Indian Institute of Chemical Technology
Catalysis Today | Year: 2013

Ordered mesoporous two-dimensional coppersilicate catalyst (CuSBA-15) has been prepared by direct method under acidic conditions. The catalyst is characterized by XRD, nitrogen sorption and HR-TEM. The nitrogen adsorption measurement indicates that the materials possess BET specific surface area ca. 692 m2/g. Electron microscopy images prove that the CuSBA-15 possesses ordered structure with uniform pore channels. Further, the catalyst is utilized for three component coupling reaction of aldehydes, amines and alkynes, for the efficient synthesis of propargylamine and their derivatives. The effect of aliphatic aldehydes and solvents on corresponding products is systematically investigated. The CuSBA-15 catalyst shows excellent yields in short reaction time. © 2013 Elsevier B.V.


Bhosale S.V.,RMIT University | Al Kobaisi M.,RMIT University | Bhosale R.S.,Indian Institute of Chemical Technology | Bhosale S.V.,Indian Institute of Chemical Technology
RSC Advances | Year: 2013

The self-assembly of two new acene diimides bearing alkyl or triethylene glycol motifs leads to the formation of a variety of nanostructures such as tubular nanofibers, donut-like, flake-like, leaf-like and other morphologies. The formed nanostructures were evaluated using UV-Vis, fluorescence and scanning electron microscopy. © The Royal Society of Chemistry 2013.


Reddy B.M.,Indian Institute of Chemical Technology | Durgasri N.,Indian Institute of Chemical Technology | Kumar T.V.,Indian Institute of Chemical Technology | Bhargava S.K.,RMIT University
Catalysis Reviews - Science and Engineering | Year: 2012

Among various pollutants, mercury has a significant impact on the environment, human beings, and wildlife with its different forms, namely, elemental mercury (Hg0), oxidized mercury (Hg 2+), and particle-bound mercury (Hgp). Mercury dispersions mainly occur from coal burning, which is the world's major energy source. Among the three forms, Hg 2+ and Hgp are relatively easy to remove from the flue gas by employing typical air pollution control devices; on the other hand, Hg0 is difficult to remove. Various methods are available to detain elemental mercury. Recent developments in mercury removal options, especially during the last years, are reviewed. Main concentration has been focused on the removal methods of elemental mercury by novel sorbents and catalytic systems. A current challenge is to develop novel nanomaterials meeting rigorous requirements (easy separation, recyclability, and cost-effectiveness) for eventual exploitation. Copyright © Taylor & Francis Group, LLC.


Singh S.P.,Indian Institute of Chemical Technology | Gupta K.S.V.,Indian Institute of Chemical Technology | Sharma G.D.,R and nter for Engineering and Science | Islam A.,Japan National Institute of Materials Science | Han L.,Japan National Institute of Materials Science
Dalton Transactions | Year: 2012

We have designed and synthesized a new thiocyanate-free sensitizer coded as SPS-01 and used it as the sensitizer in a TiO 2 based nanocrystalline dye-sensitized solar cell (DSSC). SPS-01 exhibits strong visible absorption properties with maximum peak around at 532 nm. The overall power conversion efficiency (PCE) of a DSSC sensitized with SPS-01 (7.96%) is higher than that of N719 (7.30%) under identical experimental conditions. This high PCE is attributed mainly due to the improvement in the short circuit current. © 2012 The Royal Society of Chemistry.


Banerjee A.,Indian Institute of Chemical Technology | Banerjee A.,Bangabasi College | De M.,Indian Institute of Chemical Technology | Ali N.,Indian Institute of Chemical Technology
Antimicrobial Agents and Chemotherapy | Year: 2011

Visceral leishmaniasis (VL) caused by the parasite Leishmania donovani is a potentially fatal disease. Available limited drugs are toxic, require prolonged treatment duration, and are costly. A low-cost parenteral formulation of paromomycin sulfate (PM) has recently been approved for the treatment of VL. Monotherapy with PM runs the risk of development of resistance. Hence, efforts are needed to develop a combination therapy of PM with other drugs to shorten the duration of treatment and prolong the effective life of the drug. PM was formulated with leishmanicidal stearylamine (SA)-bearing phosphatidylcholine (PC) liposomes for low-dose therapy. In vitro and in vivo antileishmanial effects of the combination drug were determined. The immunomodulatory role of PC-SA - PM was determined using enzyme-linked immunosorbent assay (ELISA) and flow cytometry. Excluding the spleen, for which the therapeutic effect was additive, a remarkable synergistic activity toward cure and prophylaxis with a single-shot low-dose treatment with PC-SA-associated PM was achieved with BALB/c mice. PC-SA - PM showed an immunomodulatory effect on CD4 + and CD8 + T cells for gamma interferon (IFN-γ) production and downregulated disease-associated interleukin-10 (IL-10) and transforming growth factor β (TGF-β) to almost negligible levels. Such combination chemotherapy may provide a promising alternative for the cure of leishmaniasis, with a plausible conversion of the host immune response from a disease-promoting pattern to a Th1-biased response indicative of long-term resistance. Copyright © 2011, American Society for Microbiology. All Rights Reserved.


Appa Rao B.V.,National Institute of Technology Warangal | Iqbal Md.Y.,National Institute of Technology Warangal | Sreedhar B.,Indian Institute of Chemical Technology
Electrochimica Acta | Year: 2010

5-Methoxy-2-(octadecylthio)benzimidazole (MOTBI) monolayer was self-assembled on fresh copper surface obtained after etching with nitric acid at ambient temperature. The optimum conditions for formation of self-assembled monolayer (SAM) were established using impedance studies. The optimum conditions are methanol as solvent, 10 mM concentration of the organic molecule and an immersion period of 24 h. The MOTBI SAM on copper surface was characterized by contact angle measurements, X-ray photoelectron spectroscopy and reflection absorption FTIR spectroscopy and it is inferred that chemisorption of MOTBI on copper surface is through nitrogen. Corrosion protection ability of MOTBI SAM was evaluated in aqueous NaCl solution using impedance, electrochemical quartz crystal nanobalance, potentiodynamic polarization and weight-loss studies. While bare copper showed a charge-transfer resistance (Rct) value of 1.89 kΩ cm2 in 0.20 M NaCl aqueous environment, the Rct value for SAM covered copper surface is 123.4 kΩ cm2. The MOTBI SAM on copper afforded corrosion inhibition efficiency of 98-99% in NaCl solution in the concentration range and in the temperature range studied. The SAM functions as a cathodic inhibitor. Quantum chemical calculations showed that MOTBI has relatively small ΔE between HOMO and LUMO and large negative charge in its benzimidazole ring, which facilitate formation of a polymeric [Cu+-MOTBI] complex on copper surface. © 2009 Elsevier Ltd. All rights reserved.


Menon R.S.,Indian Institute of Chemical Technology | Biju A.T.,CSIR - National Chemical Laboratory | Nair V.,Indian National Institute for Interdisciplinary Science and Technology
Chemical Society Reviews | Year: 2015

The use of NHCs for generating homoenolate species has gained widespread popularity in recent years. A number of highly stereoselective processes of NHC-homoenolates have emerged. Homoenolate reactions have also been employed as key steps in the total synthesis of a number of natural products. The use of compatible co-catalysts, improved NHC-catalyst design and the use of novel precursors for homoenolate generation are among the major developments in this area that were disclosed recently. This tutorial review organises and presents the advancements in this rapidly growing area of catalysis and in the process updates a previous account published in 2011 in this journal. This journal is © The Royal Society of Chemistry.


Singh S.P.,Indian Institute of Chemical Technology | Sharma G.D.,R and nter for Engineering and Science
Chemical Record | Year: 2014

Dye sensitized solar cells (DSSCs) and bulk heterojunction (BHJ) solar cells have been the subject of intensive academic interest over the past two decades, and significant commercial effort has been directed towards this area with the vison of developing the next generation of low cost solar cells. Materials development has played a vital role in the dramatic improvement of both DSSC and BHJ solar cell performance in the recent years. Organic conjugated polymers and small molecules that absorb solar light in the visible and near infrared (NIR) regions represent a class of emering materials and show a great potential for the use of different optoelectronic devices such as DSSCs and BHJ solar cells. This account describes the emering class of near infrared (NIR) organic polymers and small molecules having donor and acceptors units, and explores their potential applications in the DSSCs and BHJ solar cells. Near-infrared organic materials: Organic conjugated polymers and small molecules that absorb solar light in the visible and near-infrared regions represents a class of emerging materials and show a great potential for the use of different optoelectronic devices such as DSSCs and BHJ solar cells. This review describes the emering class of near-infrared organic polymers and small molecules having donor and acceptors units, and explores their potential applications in DSSCs and BHJ solar cells. Copyright © 2014 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


Bhosale S.V.,RMIT University | Bhosale S.V.,Indian Institute of Chemical Technology | Bhargava S.K.,RMIT University
Organic and Biomolecular Chemistry | Year: 2012

Core-substituted naphthalenediimides (cNDIs) are rapidly emerging as a powerful strategy to create functional nanomaterials and their implications in biological and supramolecular chemistry are significant. Recent developments in the synthesis of cNDIs have allowed several groups to probe the function of this interesting class of dye molecules in a molecular and supramolecular sense. Core-substitution of the NDI can be seen as an opportunity to extend the planar, rigid core and could be used to prepare novel structures for applications in organic, biosupramolecular chemistry, biomedicine, materials science and organic solar cells. In this Emerging Area, we provide up-to-date recent progress in the field of cNDIs. We begin with a general discussion and the applications of cNDIs in the field of supramolecular chemistry i.e. generation of nanostructures such as vesicles and nanotubes etc., and we also discuss advances in artificial photosynthesis. Following this is a section on their implications in the field of sensors, particularly DNA intercalation, anion sensing and NDI based pH sensors. Finally, we explore the recent development of cNDIs in organic solar cell applications. We conclude with our views on the prospects of cNDIs in future research. This journal is © 2012 The Royal Society of Chemistry.


News Article | November 13, 2015
Site: www.nanotech-now.com

Abstract: RMIT University researchers have developed artificial microflowers that self-assemble in water and mimic the natural blooming process, an important step for advances in frontier-edge electronics Flower-shaped structures have been the focus of research because their distinctive surfaces offer exciting potential for applications in a range of fields - from optoelectronics and chemosensors to nanotechnology, biotechnology, biomedicine and organic electronics. The team from the RMIT-Indian Institute of Chemical Technology Research Centre has for the first time developed microstructures shaped like flowers that build through self-repeating arrangement in water. Lead investigator Dr Sheshanath Boshanale said the field of organic flower-shaped morphology was still in its infancy. "This is the first time flower-shaped microforms have been developed in a water solution, opening an exciting new pathway for further research," he said. "The artificial blooms developed by our team are just 10 microns wide - about 10 could fit along the width of a strand of human hair. "While tiny, they have potential to make a big impact by enabling researchers to easily and reliably build microflowers and use them to break frontiers in a range of scientific fields." To create the microflowers, researchers mixed two organic components (NDI-bearing phosphonic acid and melamine) in water, which is then evaporated. The artificial microflowers take about three hours to fully develop, mimicking the way natural flowers bloom. The research has been published in Scientific Reports, a high-impact open-access journal from the publishers of Nature. For more information, please click If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.


Arundhathi R.,Indian Institute of Chemical Technology | Damodara D.,Indian Institute of Chemical Technology | Likhar P.R.,Indian Institute of Chemical Technology | Kantam M.L.,Indian Institute of Chemical Technology | And 3 more authors.
Advanced Synthesis and Catalysis | Year: 2011

A high surface, magnetic Fe3O4@mesoporouspolyaniline core-shell nanocomposite was synthesized from magnetic iron oxide (Fe 3O4) nanoparticles and mesoporouspolyaniline (mPANI). The novel porous magnetic Fe3O4 was obtained by solvothermal method under sealed pressure reactor at high temperature to achieve high surface area. The mesoporouspolyaniline shell was synthesized by in situ surface polymerization onto porous magnetic Fe3O4 in the presence of polyvinylpyrrolidone (PVP) and sodium dodecylbenzenesulfonate (SDBS), as a linker and structure-directing agent, through 'blackberry nanostructures' assembly. The material composition, stoichiometric ratio and reaction conditions play vital roles in the synthesis of these nanostructures as confirmed by variety of characterization techniques. The role of the mesoporouspolyaniline shell is to stabilize the porous magnetic Fe3O4 nanoparticles, and provide direct access to the core Fe3O4 nanoparticles. The catalytic activity of magnetic Fe3O 4@mesoporousPANI nanocomposite was evaluated in the cross-coupling of aryl chlorides and phenols. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Vinod V.T.P.,Indian Department of Atomic Energy | Sashidhar R.B.,Osmania University | Sreedhar B.,Indian Institute of Chemical Technology
Journal of Hazardous Materials | Year: 2010

Gum kondagogu (Cochlospermum gossypium), an exudates tree gum from India was explored for its potential to decontaminate toxic metal ions in aqueous solution. The toxic metal ions nickel and total chromium biosorption capacity of the gum kondagogu were studied in the batch experimental mode. The optimum conditions of biosorption were determined by investigating pH, contact time, and initial metal ion and biosorbent concentrations. The Freundlich and Langmuir adsorption models were used for the mathematical description of biosorption equilibrium and the data were analyzed on the basis of pseudo-second-order kinetic model. The maximum biosorption capacity of gum kondagogu as calculated by Langmuir model were found to be 50.5mgg-1 for nickel at pH 5.0±0.1 and 129.8mgg-1 for total chromium at pH 2.0±0.1, respectively. FTIR, SEM-EDXA and XPS analysis were used to evaluate the binding characteristics of gum kondagogu with metals. The experimental results demonstrate that the metal-ion interaction occurs through ion-exchange, adsorption and precipitation mechanisms. © 2010 Elsevier B.V.


Chaturvedi M.,Nencki Institute of Experimental Biology | Sreedhar B.,Indian Institute of Chemical Technology | Khrestchatisky M.,Aix - Marseille University | Kaczmarek L.,Nencki Institute of Experimental Biology
International Journal of Nanomedicine | Year: 2014

Aim: The aim of this study was to develop poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) for delivery of a protein-tissue inhibitor of matrix metalloproteinases 1 (TIMP-1)-across the blood-brain barrier (BBB) to inhibit deleterious matrix metalloproteinases (MMPs). Materials and methods: The NPs were formulated by multiple-emulsion solvent-evaporation, and for enhancing BBB penetration, they were coated with polysorbate 80 (Ps80). We compared Ps80-coated and uncoated NPs for their toxicity, binding, and BBB penetration on primary rat brain capillary endothelial cell cultures and the rat brain endothelial 4 cell line. These studies were followed by in vivo studies for brain delivery of these NPs. Results: Results showed that neither Ps80-coated nor uncoated NPs caused significant opening of the BBB, and essentially they were nontoxic. NPs without Ps80 coating had more binding to endothelial cells compared to Ps80-coated NPs. Penetration studies showed that TIMP-1NPs+Ps80 had 11.21%±1.35% penetration, whereas TIMP-1 alone and TIMP-1NPs without Ps80 coating did not cross the endothelial monolayer. In vivo studies indicated BBB penetration of intravenously injected TIMP-1NPs+Ps80. Conclusion: The study demonstrated that Ps80 coating of NPs does not cause significant toxic effects to endothelial cells and that it can be used to enhance the delivery of protein across endothelial cell barriers, both in vitro and in vivo. © 2014 Chaturvedi et al.


Reddy P.V.L.,Sejong University | Reddy P.V.L.,Indian Institute of Chemical Technology | Kim K.-H.,Sejong University | Song H.,Sejong University
Renewable and Sustainable Energy Reviews | Year: 2013

Climate change is a serious global concern in contemporary times, as the repercussions of this phenomenon occur conspicuously across the globe. Abatement of potential greenhouse gas (GHG) should be a simple and easy measure to counter the global warming. Instead, a lot of research emphasis has been put on various green technologies, through which the undesirable GHG components like methane can be converted into value added by-products. The recent promising discoveries of several methane capturing technologies at sources and of enhancing its high calorific value have surely laid a new pathway for its treatment/utilization. Here, in this review we carried out a thorough survey on many importantly emerging green technological options and their effectiveness as control measures. To this end, we explored the basic characteristics of many relevant technologies including catalytic, plasma, supercritical water, photocatalysis, membrane, solar splitting, and other relevant technologies. All of these options are surely feasible enough to process methane on one hand and to yield variety of useful chemicals as byproduct (e.g., hydrogen, methanol, formaldehyde, and aromatics) on the other hand. © 2013 Elsevier Ltd.


Layek K.,Indian Institute of Chemical Technology | Kantam M.L.,Indian Institute of Chemical Technology | Shirai M.,Japan National Institute of Advanced Industrial Science and Technology | Nishio-Hamane D.,University of Tokyo | And 2 more authors.
Green Chemistry | Year: 2012

Gold nanoparticles deposited on nanocrystalline magnesium oxide is a very efficient catalyst for the reduction of nitroarenes in aqueous medium at room temperature. Sodium borohydride is used as the source of hydrogen for the reduction of nitro groups. This catalytic system selectively reduces the nitro group even in the presence of other sensitive functional groups under very mild conditions in good to excellent yields without the requirement of any promoters. The reaction kinetics of reduction of 4-nitrophenol to 4-aminophenol has been studied by UV-visible spectrophotometry, and its apparent rate constant has been determined and compared with those of other supported gold catalysts. The spent heterogeneous catalyst is recovered by simple centrifugation, and reused for multiple cycles. © 2012 The Royal Society of Chemistry.


Sullad A.G.,Karnatak University | Manjeshwar L.S.,Karnatak University | Aminabhavi T.M.,Indian Institute of Chemical Technology
Journal of Applied Polymer Science | Year: 2010

Interpenetrating polymer network (IPN) microspheres of poly(vinyl alcohol) (PVA) and methylcellulose (MC) prepared by a water-in-oil emulsion method were crosslinked by glutaraldehyde and loaded with theophylline (THP), an antiasthmatic drug, with various ratios of PVA to MC. Microspheres were characterized with X-ray diffraction to determine the crystalline nature of the drug after encapsulation. Fourier transform infrared spectroscopy was used to assess the formation of the IPN structure and to confirm the absence of chemical interactions between the drug, polymer, and crosslinking agent. Differential scanning calorimetry confirmed the molecular-level distribution of THP in the polymer matrix, whereas scanning electron microscopy suggested the formation of clustered spherical particles. Zetasizer indicated that the particle sizes ranged from 4 to 57 μm. A THP encapsulation efficiency of up to 84% was achieved, as confirmed by ultraviolet spectrophotometry. Dynamic/equilibrium swelling experiments performed in pH 7.4 buffer media provided important information on drug diffusion characteristics. in vitro release studies performed in pH 1.2 and 7.4 buffer media indicated that the drug release depended on the extent of crosslinking as well as the amount of MC in the microspheres. Drug release was extended up to 3 h, and the results, as analyzed with an empirical equation, indicated non-Fickian transport for the release of THP. © 2009 Wiley Periodicals, Inc.


Damodara D.,Indian Institute of Chemical Technology | Arundhathi R.,Indian Institute of Chemical Technology | Arundhathi R.,Osaka University | Likhar P.R.,Indian Institute of Chemical Technology
Catalysis Science and Technology | Year: 2013

A high surface area mPANI/pFe3O4 nanocomposite from mesoporous polyaniline and porous magnetic Fe3O4 was used as a catalyst in the S-arylation of thiophenol with aryl chlorides and in the C-S bond formation between aryl iodides and thiourea in water. The mesoporosity of the polyaniline enhances the efficiency and stability of the porous magnetic Fe3O4 nanoparticles in both coupling reactions. The mPANI/pFe3O4 nanocomposite can be recovered with an external magnet and reused several times due to the superparamagnetic nature of the porous Fe3O4 nanoparticles. © 2013 The Royal Society of Chemistry.


Kavitha A.,Acharya Nagarjuna University | Prabhakar P.,Indian Institute of Chemical Technology | Vijayalakshmi M.,Acharya Nagarjuna University | Venkateswarlu Y.,Indian Institute of Chemical Technology
Research in Microbiology | Year: 2010

An Actinobacterium strain isolated from laterite soils of the Guntur region was identified as Streptomyces sp. TK-VL_333 by 16S rRNA analysis. Cultural, morphological and physiological characteristics of the strain were recorded. The secondary metabolites produced by the strain cultured on galactose-tyrosine broth were extracted and concentrated followed by defatting of the crude extract with cyclohexane to afford polar and non-polar residues. Purification of the two residues by column chromatography led to isolation of five polar and one non-polar fraction. Bioactivity- guided fractions were rechromatographed on a silica gel column to obtain four compounds, namely 1. H-indole-3-carboxylic acid, 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one and acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester from three active polar fractions and 8-methyl decanoic acid from one non-polar fraction. The structure of the compounds was elucidated on the basis of FT-IR, mass and NMR spectroscopy. The antimicrobial activity of the bioactive compounds produced by the strain was tested against the bacteria and fungi and expressed in terms of minimum inhibitory concentration. Antifungal activity of indole-3-carboxylic acid was further evaluated under in vitro and in vivo conditions. This is the first report of 2,3-dihydroxy-5-(hydroxymethyl) benzaldehyde, 4-(4-hydroxyphenoxy) butan-2-one, acetic acid-2-hydroxy-6-(3-oxo-butyl)-phenyl ester and 8-methyl decanoic acid from the genus Streptomyces. © 2010 Elsevier Masson SAS.


Bania K.K.,Tezpur University | Karunakar G.V.,Indian Institute of Chemical Technology | Goutham K.,Indian Institute of Chemical Technology | Deka R.C.,Tezpur University
Inorganic Chemistry | Year: 2013

Two chiral Schiff-base complexes of copper(II) have been successfully encapsulated inside the cavity of zeolite-NaY via a "ship in a bottle" synthesis method. The presence of the two complexes inside the cages of zeolite-Y has been confirmed based on various spectrochemical and physicochemical techniques, viz. FTIR, UV-vis/DRS, ESR, XPS, CV, EDX, SEM, and TGA. Zeolite-encapsulated chiral copper(II) Schiff-base complexes are found to give a high-enantioselective (84% ee, R conformation) nitro-aldol product at -20 °C. The encapsulated copper complexes are found to show higher catalytic efficiency than their homogeneous counterparts under identical conditions. Density functional theory (DFT) calculation has been implemented to understand the effect of the zeolite matrix on structural, electronic, and reactivity properties of the synthesized complexes. Theoretical calculation predicts that upon encapsulation into the zeolite matrix the Cu center becomes more susceptible to nucleophilic attack, favoring a nitro-aldol reaction. A plausible mechanism is suggested based on the experimental and theoretical results. The structures of reaction intermediates and transition state(s) involved in the catalytic cycle are derived using DFT. © 2013 American Chemical Society.


Begum G.,Indian Institute of Chemical Technology | Rana R.K.,Indian Institute of Chemical Technology | Singh S.,India and Centrefor Cellular and Molecular Biology | Satyanarayana L.,Indian Institute of Chemical Technology
Chemistry of Materials | Year: 2010

Herein we demonstrate a simple but versatile bioinspired polyamine-catalyzed silicification route to synthesizing functional materials which is monodisperse, mesoporous, and spherically uniform having nanosizes under extremely mild conditions similar to the biosilicification processes. Employing the principles learned from nature and in particular from diatom biomineralization to integrate the functions required for silica condensation and self-assembly leads to the formation of such functional materials. Importantly, the integration of such functions requires the presence of suitable multivalent counteranions, whose interaction is structure specific while facilitating the mineralization process to form these unique silica structures under the green conditions of aqueous medium, neutral pH, and room temperature. The versatility of the method is exemplified in controlling the size, uniformity, and the nanoarchitectural features of the silica obtained within a very short time frame of 30 min. A wide variety of techniques (fluorescence imaging, live confocal imaging, dynamic light scattering, MAS 29Si NMR, N2 sorption, X-ray diffraction, FT-IR, thermo-gravimetric analysis, scanning and transmission electron microscopy) have been used to study the formation process and characterization of the materials. © 2009 American Chemical Society.


Amali A.J.,Indian Institute of Chemical Technology | Amali A.J.,Madurai Kamaraj University | Sharma B.,Indian Institute of Chemical Technology | Rana R.K.,Indian Institute of Chemical Technology
Chemistry - A European Journal | Year: 2014

In analogy to the role of long-chain polyamines in biosilicification, poly-L-lysine facilitates the assembly of nanocomponents to design multifunctional microcapsule structures. The method is demonstrated by the fabrication of a magnetically separable catalyst that accommodates Pd nanoparticles (NPs) as active catalyst, Fe3O4 NPs as magnetic component for easy recovery of the catalyst, and silica NPs to impart stability and selectivity to the catalyst. In addition, polyamines embedded inside the microcapsule prevent the agglomeration of Pd NPs and thus result in efficient catalytic activity in hydrogenation reactions, and the hydrophilic silica surface results in selectivity in reactions depending on the polarity of substrates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Iwasaki T.,Osaka University | Takagawa H.,Osaka University | Singh S.P.,Indian Institute of Chemical Technology | Kuniyasu H.,Osaka University | Kambe N.,Osaka University
Journal of the American Chemical Society | Year: 2013

The cobalt-catalyzed cross-coupling of alkyl (pseudo)halides with alkyl Grignard reagents in the presence of 1,3-butadiene as a ligand precursor and LiI is described. Sterically congested quaternary carbon centers could be constructed by using tertiary alkyl Grignard reagents. This reaction proceeds via an ionic mechanism with inversion of stereochemistry at the reacting site of the alkyl halide and is compatible with various functional groups. The use of both 1,3-butadiene and LiI was essential for achieving high yields and high selectivities. © 2013 American Chemical Society.


Chen W.,Hefei University of Technology | Yan L.,Hefei University of Technology | Bangal P.R.,Indian Institute of Chemical Technology
Journal of Physical Chemistry C | Year: 2010

Instead of hydrazine, a series of sulfur-containing compounds such as NaHSO 3, Na 2SO 3, Na 2S 2O 3, Na 2S·9H 2O, SOCl 2, and SO 2, were used as reducing agents to reduce graphene oxide to graphene. Fourier transform infrared spectrometry, atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, elemental analysis, and thermogravimetric analysis confirmed the formation of graphene under chemical reduction at 95 °C. The results reveal that the reducing ability of NaHSO 3 is comparable to that of hydrazine. This newly found reducing agent is of low toxicity and nonvolatile, which makes the reduction much safer than hydrazine. A possible mechanism of the reduction has been suggested. The electrical conductivity of the graphene paper prepared using a NaHSO 3 reducing agent is found to be 6500 S m -1, while it is observed to be 5100 S m -1 for hydrazine-reduced graphene paper. These studies also confirmed that SOCl 2 can be a good candidate as a reducing agent to compete with hydrazine. © 2010 American Chemical Society.


Suryanarayana Murty U.,Indian Institute of Chemical Technology | Srinivasa Rao M.,Indian Institute of Chemical Technology | Arunachalam N.,Center for Research in Medical Entomology
Journal of Vector Borne Diseases | Year: 2010

Background & objectives: Climatic attributes have been associated with relative mosquito abundance and transmission of mosquito borne infections in many parts of the world, especially in warm and tropical climatic regions. The main objectives of this study were to assess the change in seasonal pattern of Japanese encephalitis (JE) vectors, their density, to elucidate whether the lagged climate variables (precipitation, temperature and humidity) are associated with JE vector density, and to determine if temperature and precipitation are similarly important for the rise in the number of potential mosquito vectors for JE virus in the temperate climate of Andhra Pradesh, India. Methods: Mosquito samples were collected from Kurnool district of Andhra Pradesh using hand catch and light-trap methods during 2002 to 2006. The type and abundance of recovered species were compared to ecological correlates. In each geographic area, temperature and precipitation are the two possible proxy variables for mosquito density, in conjunction with other seasonal factors for JE epidemics. Results: Out of the various mosquito species collected, Culex gelidus and Cx. tritaeniorhynchus were noticed in high numbers. There was considerably high prevalence of Cx. gelidus (68.05%) in urban area than in rural areas whereas, Cx. tritaeniorhynchus (57.51%) was found to be more in rural areas than in the urban area. It is noticed that the factors such as rainfall and temperature were found to be correlated with the per man hour (PMH) density, whereas the humidity was inversely correlated with the PMH. Interpretation & conclusion: The environmental and eco-climatic factors are assisting in enhancing the breeding of these mosquitoes in Kurnool district of Andhra Pradesh, India. Both Cx. tritaeniorhyncus and Cx. gelidus are quite adaptable to these environmental conditions and this necessitates immediate control measures in both rural and urban areas of Kurnool district.


Raghu M.,Indian Institute of Chemical Technology | Rajasekhar M.,Sri Venkateswara University | Chandra Obula Reddy B.,Indian Institute of Chemical Technology | Suresh Reddy C.,Sri Venkateswara University | Subba Reddy B.V.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

3-(Pyridylmethyl)-3-hydroxy-2-oxindole derivatives were synthesized in high yields under mild, and catalyst-free conditions using polyethylene glycol (PEG-400) as a solvent. The use of low cost PEG-400 makes it simple, convenient, and environmentally benign. © 2013 Elsevier Ltd. All rights reserved.


Nagarapu L.,Indian Institute of Chemical Technology | Mallepalli R.,Sri Venkateswara University | Yeramanchi L.,Sri Venkateswara University | Bantu R.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2011

Polyethylene glycol (PEG) was found to be an inexpensive non-toxic and effective medium for the one-pot synthesis of highly functionalized pyrroles. Utilizing this protocol various pyrrole derivatives were synthesized in excellent yields. Environmental acceptability, low cost, high yields, and recyclability of the PEG are the important features of this protocol. © 2011 Elsevier Ltd. All rights reserved.


Mohan Kumar K.,Vellore Institute of Technology | Mandal B.K.,Vellore Institute of Technology | Siva Kumar K.,Sri Venkateswara University | Sreedhara Reddy P.,Sri Venkateswara University | Sreedhar B.,Indian Institute of Chemical Technology
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013

There are many methods to synthesise metal and metal oxide nanoparticles (NPs) using different reducing agents which are hazardous in nature. Although some researchers have used biobased materials for synthesis of these NPs, further research is needed in this area. To explore the scope of bio-extract for the synthesis of transition metal NPs, the present paper synthesises metal NPs replacing hazardous traditional reducing agents. This paper reports the synthesis of palladium and iron NPs, using aqueous extract of Terminalia chebula fruit. Reduction potential of aqueous extract of polyphenolic rich T. chebula was 0.63 V vs. SCE by cyclic voltammetry study which makes it a good green reducing agent. This helps to reduce palladium and iron salts to palladium and iron NPs respectively. Powder X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) analyses revealed that amorphous iron NPs were within the size less than 80 nm and cubic palladium NPs were within the size less than 100 nm. The synthesised nanomaterials were remarkably stable for a long period and synthesis of stable metal NPs will need to be explored using biobased materials as reducing agents. © 2012 Elsevier B.V. All rights reserved.


Ramaiah K.P.,Sri Venkateswara University | Satyasri D.,Indian Institute of Chemical Technology | Sridhar S.,Indian Institute of Chemical Technology | Krishnaiah A.,Sri Venkateswara University
Journal of Hazardous Materials | Year: 2013

Hydrophobic polymer possesses significant potential for selective separation of volatile organic compounds (VOCs) from their aqueous solutions by pervaporation (PV). In the present study mixed matrix hydrophobic membranes of polydimethylsiloxane (PDMS) supported on polyvinylidenefluoride (PVDF) substrate were synthesized by incorporating hydrophobic inorganic ZSM-5 filler. The indigenous membranes were crosslinked with tetraethylorthosilicate (TEOS) for the extraction of volatile chlorinated hydrocarbons such as dichloromethane (DCM), trichloromethane (TCM), 1,2-dichloroethane (DCE), and 1,1,2,2-tetrachloroethane (TeCE), which pose serious environment threat and health hazard. Thermal stability, crosslinking, crystallinity, surface morphology and swelling characteristics of the indigenously developed membranes were determined by TGA, FTIR, XRD, SEM and sorption studies, respectively. Effect of operating parameters such as feed composition and filler concentration on separation performance in terms of flux and selectivity were determined. Flux of DCM, TCM, DCE and TeCE was found to be 0.166, 0.146, 0.141 and 0.06kgm-2h-1 with selectivity of 541, 1068, 917 and 15,000, respectively, for 20% ZSM-5 filled PDMS membrane for aqueous feeds containing 1.33% (w/v) DCM, 0.8% (w/v) TCM, 0.84% (w/v) DCE and 0.28% (w/v) TeCE in water. The membrane exhibited considerable feasibility for scale-up with significant potential for removal of hazardous chlorinated VOCs from aqueous solutions. © 2013 Elsevier B.V.


Amali A.J.,Indian Institute of Chemical Technology | Singh S.,Center for Cellular and Molecular Biology | Rangaraj N.,Center for Cellular and Molecular Biology | Patra D.,American University of Beirut | Rana R.K.,Indian Institute of Chemical Technology
Chemical Communications | Year: 2012

Counter-ion condensation of Poly(l-Lysine) in the presence of pyranine-3 generates spherical coacervates, which then template the assembly of silica nanoparticles to form microcapsule structures that dynamically control the optical ratiometric sensing of both the change in pH and release of the probe molecule.


Srilatha K.,Catalysis Laboratory | Sree R.,Catalysis Laboratory | Prabhavathi Devi B.L.A.,Indian Institute of Chemical Technology | Sai Prasad P.S.,Catalysis Laboratory | And 2 more authors.
Bioresource Technology | Year: 2012

Biodiesel synthesis from rice bran fatty acids (RBFA) was carried out using cesium exchanged 12-tungstophosphoric acid (TPA) catalysts. The physico-chemical properties of the catalysts were derived from X-ray diffraction (XRD), Fourier transform infrared (FTIR), temperature programmed desorption (TPD) of NH 3 and scanning electron microscopy (SEM). The characterization techniques revealed that the Keggin structure of TPA remained intact as Cs replaced protons. The partial exchange of Cs for protons resulted in an increase in acidity and the catalysts with one Cs + (Cs 1H 2PW 12O 40) showed highest acidity. Under optimized conditions about 92% conversion of RBFA was obtained. The catalyst was reused for five times and retained of its original activity. Pseudo-first order model was applied to correlate the experimental kinetic data. Modified tungstophosphoric acids are efficient solid acid catalysts for the synthesis of biodiesel from the oils containing high FFA. © 2012 Elsevier Ltd.


Das A.,Indian Institute of Chemical Technology | Bhadra K.,Indian Institute of Chemical Technology | Bhadra K.,Kalyani University | Kumar G.S.,Indian Institute of Chemical Technology
PLoS ONE | Year: 2011

Background: Interaction of aristololactam-β-D-glucoside and daunomycin with tRNA phe was investigated using various biophysical techniques. Methodology/Principal Findings: Absorption and fluorescence studies revealed that both the compounds bind tRNA phe non-cooperatively. The binding of daunomycin was about one order of magnitude higher than that of aristololactam-β-D-glucoside. Stronger binding of the former was also inferred from fluorescence quenching data, quantum efficiency values and circular dichroic results. Results from isothermal titration calorimetry experiments suggested that the binding of both compounds was predominantly entropy driven with a smaller but favorable enthalpy term that increased with temperature. A large favorable electrostatic contribution to the binding of daunomycin to tRNA phe was revealed from salt dependence data and the dissection of the free energy values. The electrostatic component to the free energy change for aristololactam-β-D-glucoside-tRNA phe interaction was smaller than that of daunomycin. This was also inferred from the slope of log K versus [Na +] plots. Both compounds enhanced the thermal stability of tRNA phe. The small heat capacity changes of -47 and -99 cal/mol K, respectively, observed for aristololactam-β-D-glucoside and daunomycin, and the observed enthalpy-entropy compensation phenomenon confirmed the involvement of multiple weak noncovalent interactions. Molecular aspects of the interaction have been revealed. Conclusions/Significance: This study presents the structural and eneregetic aspects of the binding of aristololactam-β-D-glucoside and daunomycin to tRNA phe. © 2011 Das et al.


Yempala T.,Indian Institute of Chemical Technology | Sriram D.,Birla Institute of Technology and Science | Yogeeswari P.,Birla Institute of Technology and Science | Kantevari S.,Indian Institute of Chemical Technology
Bioorganic and Medicinal Chemistry Letters | Year: 2012

A novel series of natural product like dibenzofuran embodied homoisoflavonoids [(E)-3-(dibenzo[b,d]furan-2-ylmethylene)chroman-4-ones] designed by molecular hybridization were synthesized in very good yields via a sequence of reactions involving base catalyzed Baylis-Hillmann (BH) reaction of 2-dibenzofuran carboxaldehyde and methyl acrylate; bromination of BH adduct; condensation of resulted allylic bromide with substituted phenols or 2-dibenzofuranol followed by cyclization. Among the all 11 new compounds screened for in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv (MTB), (E)-3-(dibenzo[b,d]furan-2-ylmethylene)-6- fluorochroman-4-one (7f) and (E)-3-(dibenzo[b,d] furan-2-ylmethylene)-6- fluorochroman-4-one (7g) were found to be active with MIC 12.5 μg/mL. © 2012 Elsevier Ltd. All rights reserved.


Amali A.J.,Indian Institute of Chemical Technology | Awwad N.H.,American University of Beirut | Rana R.K.,Indian Institute of Chemical Technology | Patra D.,American University of Beirut
Analytica Chimica Acta | Year: 2011

The encapsulation of molecular probes in a suitable nanostructured matrix can be exploited to alter their optical properties and robustness for fabricating efficient chemical sensors. Despite high sensitivity, simplicity, selectivity and cost effectiveness, the photo-destruction and photo-bleaching are the serious concerns while utilizing molecular probes. Herein we demonstrate that hydroxy pyrene trisulfonate (HPTS), a pH sensitive molecular probe, when encapsulated in a microcapsule structure prepared via the assembly of silica nanoparticles mediated by poly- l-lysine and trisodium citrate, provides a robust sensing material for pH sensing under the physiological conditions. The temporal evolution under continuous irradiation indicates that the fluorophore inside the silica microcapsule is extraordinarily photostable. The fluorescence intensity alternation at dual excitation facilitates for a ratiometic sensing of the pH, however, the fluorescence lifetime is insensitive to hydrogen ion concentration. The sensing scheme is found to be robust, fast and simple for the measurement of pH in the range 5.8-8.0, and can be successfully applied for the determination of ammonia in the concentration range 0-1.2. mM, which is important for aquatic life and the environment. © 2011 Elsevier B.V.


Pallela R.,Pukyong National University | Venkatesan J.,Pukyong National University | Janapala V.R.,Indian Institute of Chemical Technology | Kim S.-K.,Pukyong National University
Journal of Biomedical Materials Research - Part A | Year: 2012

Tricomponent scaffold systems prepared by natural materials especially of marine origin are gaining much attention nowadays for the application in bone tissue engineering. A novel scaffold (Chi-HAp-MSCol) containing chitosan (Chi), hydroxyapatite (HAp) derived from Thunnus obesus bone and marine sponge (Ircinia fusca) collagen (MSCol) was prepared using freeze-drying and lyophilization method. This biomimetic scaffold, along with the Chi and Chi-HAp scaffolds were characterized biophysicochemically for their comparative significance in bone grafting applications. The structural composition of the chitosan, Chi-Hap, and Chi-HAp-MSCol scaffolds were characterized by Fourier Transform Infrared spectroscopy. The porosity, water uptake, and retention abilities of the composite scaffolds decreased, whereas Thermogravimetric and Differential Thermal Analyses results revealed the increase in thermal stability in the scaffold because of the highly stable HAp and MSCol. Homogeneous dispersion of HAp and MSCol in chitosan matrix with interconnected porosity of 60-180 μm (Chi-HAp) and 50-170 μm (Chi-HAp-MSCol) was observed by Scanning Electron Microscopy, X-ray diffraction, and optical microscopy. Cell proliferation in composite scaffolds was relatively higher than pure chitosan when observed by MTT assay and Hoechst staining in vitro using MG-63 cell line. These observations suggest that the novel Chi-HAp-MSCol composite scaffolds are promising biomaterials for matrix-based bone repair and bone augmentation. Copyright © 2011 Wiley Periodicals, Inc.


Sreedhar I.,BITS Pilani Hyderabad Campus | Singh M.,BITS Pilani Hyderabad Campus | Raghavan K.V.,Indian Institute of Chemical Technology
Catalysis Science and Technology | Year: 2013

The nitration of toluene is an ubiquitous reaction whose mono nitro products find applications in pharmaceuticals, perfumes, explosives and plastics. The conventional process of treating toluene with mixed acids leads to an undesirable product distribution besides being energy intensive and environmentally unfriendly. Hence the worldwide research on alternative greener technologies has intensified. This paper provides a comprehensive review on the sulfuric acid free nitration of toluene covering alternative options on nitrating agents, catalysts, their properties, compatible solvents, reaction media, process kinetics, mechanisms and reaction engineering studies. New opportunity areas for future research are identified. © 2013 The Royal Society of Chemistry.


Ramani T.,Indian Institute of Chemical Technology | Umadevi P.,Indian Institute of Chemical Technology | Prasanth K.L.,Zamorins Guruvayurappan College | Sreedhar B.,Indian Institute of Chemical Technology
European Journal of Organic Chemistry | Year: 2013

ortho-Benzoylation of phenols with aryl aldehydes to afford the substituted 2-hydroxybenzophenones can be catalyzed efficiently by Fe3O 4 nanoparticles under ligand-free conditions. This method is useful for the preparation of xanthones in good yields. The catalyst can be magnetically removed and recycled easily over four cycles without a significant decrease in activity. The applicability of magnetically retrievable Fe 3O4 nanoparticles in the oxidative coupling of aryl aldehydes with phenols under ligand free conditions is demonstrated. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Deb I.,Indian Institute of Science | Chakraborty J.,Baulmon | Gangopadhyay P.K.,Calcutta National Medical College Hospital | Choudhury S.R.,Indian Institute of Chemical Technology | Das S.,Indian Institute of Science
Journal of Neurochemistry | Year: 2010

The opioid receptor mu1 (OPRM1) mediates the action of morphine. Although genetic background plays an important role in the susceptibility toward abuse of drugs as evident from familial, adoption and twin studies, association of specific single-nucleotide polymorphisms of OPRM1 gene with narcotic addiction is to be established. Here, we demonstrate the involvement of A118G polymorphism of exon1 of human OPRM1 gene (hOPRM1), with heroin and alcohol addiction, in a population in eastern India. Statistical analysis exhibited a significant association of G allele with both heroin and alcohol addiction with a risk factor of Ptrend < 0.05. The functional significance of G allele in A118G single-nucleotide polymorphisms was evaluated by studying the regulation of protein kinase A (PKA), pCREB, and pERK12 by morphine in Neuro 2A cells, stably transfected with either wild type or A118G mutant hOPRM1. Unlike acute morphine treatment, both chronic morphine exposure and withdrawal precipitated by naloxone were differentially regulated by A118 and G118 receptor isoforms when both PKA and pERK12 activities were compared. Results suggest that the association of A118G polymorphism to heroin and alcohol addiction may be because of the altered regulation of PKA and pERK12 during opioid and alcohol exposures. © 2009 International Society for Neurochemistry.


Han D.,Anhui University of Science and Technology | Yan L.,Anhui University of Science and Technology | Chen W.,Anhui University of Science and Technology | Li W.,Anhui University of Science and Technology | Bangal P.R.,Indian Institute of Chemical Technology
Carbohydrate Polymers | Year: 2011

Regenerated cellulose/graphite oxide (GO) blended films have been prepared in 6 wt.%NaOH/4 wt.%urea aqueous solution by a simple and cost effective method. The structure, thermal stability and mechanical properties of these composite films have been investigated by wide-angle X-ray diffraction, scanning electron microscopy, thermal analyses, and tensile strength measurements. The results obtained from those different studies revealed that cellulose and GO are mixed homogeneously. The thermal stability and mechanical properties of the composite materials are improved significantly over those of pure cellulose. The cellulose/GO film showed a high storage modulus up to 180 °C. The effect of the amount of GO content in the composite material has also been investigated. © 2010 Elsevier Ltd. All rights reserved.


Gupta K.S.V.,Indian Institute of Chemical Technology | Suresh T.,Indian Institute of Chemical Technology | Singh S.P.,Indian Institute of Chemical Technology | Islam A.,Japan National Institute of Materials Science | And 2 more authors.
Organic Electronics: physics, materials, applications | Year: 2014

Three novel carbazole-based A-π-D-π-A-featured dyes (CSG1-CSG3) have been designed, synthesized for applications in dye-sensitized solar cells and fully characterized with NMR, MS, IR, UV-vis and electrochemical measurements. These dyes share the same donor (N-hexylcarbazole) and acceptor/anchoring group (cyanoacrylic acid), but differs in conjugated linkers incorporated, such as benzene, furan or thiophene, to configure the novel A-π-D-π-A framework for effective electron flow. The power conversion efficiencies were observed to be sensitive to the π-bridging linker moiety. The photovoltaic experiments showed that dye with a benzene linker exhibited a higher open-circuit voltage (0.699 V) compared to thiophene and furan linker. Among all dyes, CSG2 containing a thiophene linker exhibited the maximum overall conversion efficiency of 3.8% (JSC = 8.90 mA cm-2, VOC = 584 mV, FF = 0.74) under standard global AM 1.5 G solar condition. Under similar fabrication conditions, champion dye N719 exhibited the maximum overall conversion efficiency of 6.4% (JSC = 14.74 mA cm- 2, VOC = 606 mV, FF = 0.716). © 2013 Elsevier B.V. All rights reserved.


Han L.,Japan National Institute of Materials Science | Islam A.,Japan National Institute of Materials Science | Chen H.,Japan National Institute of Materials Science | Malapaka C.,Indian Institute of Chemical Technology | And 4 more authors.
Energy and Environmental Science | Year: 2012

A new record efficiency (11.4%) of dye-sensitized solar cell was obtained by design and syntheses of donor-acceptor type co-adsorbents which effectively overcome the competitive light absorption by I -/I 3 -, avoid dye aggregation, and reduce the charge recombination. This result was certified by a public research center (AIST). © 2012 The Royal Society of Chemistry.


Kamal A.,Indian Institute of Chemical Technology | Srinivasulu V.,Indian Institute of Chemical Technology | Seshadri B.N.,Indian Institute of Chemical Technology | Markandeya N.,Indian Institute of Chemical Technology | And 2 more authors.
Green Chemistry | Year: 2012

Heterogeneous palladium nanoparticle catalysts that are supported on amphiphilic carbon spheres (Pd@CSP) have been utilized for water-mediated Heck coupling reactions of aryl halides with different alkenes under phosphine free as well as aerobic conditions. Furthermore, a variety of Heck coupling reactions using different bases and solvents, including organic polar and non-polar solvents, have been explored. Aryl bromides are also well activated in Heck coupling reactions in organic polar solvent and as well as in water. In addition, Ullmann coupling reactions of aryl iodides have been catalyzed in water with the aid of phase transfer catalysts (PTC) in moderate yields. A plausible mechanism for the catalytic activity of Pd@CSP in the case of the Ullmann reaction is also established. It has been demonstrated that the hydrophobic effects of the catalyst surface play an important role in catalyst activity in water. In addition, the E-factor analysis verified that our present protocol is significantly comparable with other catalytic systems and explains the improved greenness. Moreover, the catalyst described in this process is not only greener, but also retains its significant activity for up to four catalytic cycles for the Heck coupling reactions. The surface polarity of the amphiphilic carbon spheres results in higher activity under these conditions. © 2012 The Royal Society of Chemistry.


Sunitha K.,Indian Institute of Chemical Technology | Satyanarayana S.V.,Jawaharlal Nehru Technological University Anantapur | Sridhar S.,Indian Institute of Chemical Technology
Carbohydrate Polymers | Year: 2012

Dense membranes of chitosan were prepared and ionically crosslinked with phosphoric acid for varying intervals of time. The membranes were characterized by FTIR and XRD to confirm cross-linking. TGA and IEC studies were conducted to assess the thermal stability and estimate the number of interactive groups left in the membrane after crosslinking. Sorption studies were carried out to evaluate the extent of interaction and degree of swelling of the membranes in pure liquids as well as binary mixtures. The phosphorylated chitosan membrane crosslinked for 2 h showed good mechanical strength and strong potential for breaking the azeotrope of 95.58 wt% ethanol by exhibiting a high pervaporation selectivity of 213 with substantial water flux of 0.58 kg/(m2 h). Pervaporation experimental parameters such as feed composition, membrane thickness and permeate pressure were varied to identify optimum operating conditions. © 2011 Elsevier Ltd. All rights reserved.


Ravikumar Y.V.L.,Indian Institute of Chemical Technology | Sridhar S.,Indian Institute of Chemical Technology | Satyanarayana S.V.,Jawaharlal Nehru Technological University Anantapur
Separation and Purification Technology | Year: 2013

Recovery of solvents from aqueous industrial effluents containing hazardous compounds is not directly feasible by conventional methods due to the complex nature of such wastewaters. An effluent from a pharmaceutical industry contains 2-3 wt% explosive sodium azide + corrosive ammonium chloride salts, 15-20% dimethylsulfoxide (DMSO) solvent and water. The focus of this work is to establish a hybrid process to facilitate removal of salts by electrodialysis (ED) followed by distillation to recover DMSO. An indigenously constructed ED system of 1.05 m2 membrane area was used to process 10 L batch size. Pure DMSO was recovered from desalted liquor by vacuum distillation in two stages to obtain DMSO concentration up to 60-70% in the first stage and subsequent recovery of pure DMSO in the second. Effect of operating parameters such as flow rate, limiting current density and voltage was evaluated. Distillation was carried out at 20-30 mmHg at reboiler temperature below 150 °C. Drug prepared using the recycled DMSO (>99.5%) was found to meet desired specifications. Detailed design of the ED-distillation process scheme to treat 7500 L/day of the effluent revealed that it was technically and economically feasible, since 30 Metric Tonnes of solvent has been recovered by the industry. © 2013 Elsevier B.V. All rights reserved.


Layek K.,Indian Institute of Chemical Technology | Chakravarti R.,Japan National Institute of Materials Science | Lakshmi Kantam M.,Indian Institute of Chemical Technology | Maheswaran H.,Indian Institute of Chemical Technology | Vinu A.,Japan National Institute of Materials Science
Green Chemistry | Year: 2011

A simple and elegant synthesis of gold nanoparticles via counter ion stabilization of AuCl 4 - on nanocrystalline magnesium oxide support followed by sodium borohydride reduction is described here. A thorough characterization of the resulting heterogeneous material revealed the presence of uniformly distributed gold nanoparticles (10-12 nm) deposited on to (111) plane of quasi-crystalline icosahedral lattice of nanocrystalline magnesium oxide which exhibits excellent catalytic activity for the one pot synthesis of structurally divergent propargylamines via a three component coupling of an alkyne, an amine and an aldehyde without requiring any additives or inert atmosphere. The catalyst contains ultra low loading of gold (0.236 mol%), and turnover numbers as high as 400 are obtained. The catalyst can be isolated by simple centrifugation and reused for four cycles. © 2011 The Royal Society of Chemistry.


Bodduluru L.N.,National Institute of Pharmaceutical Education and Research | Kasala E.R.,National Institute of Pharmaceutical Education and Research | Thota N.,National Institute of Pharmaceutical Education and Research | Barua C.C.,Assam Agricultural University | Sistla R.,Indian Institute of Chemical Technology
Toxicology in Vitro | Year: 2014

Cancer chemoprevention is a strategy taken to block, reverse or retard the multistep process of carcinogenesis, including the blockage of its vital morphogenetic milestones viz. normal-preneoplasia-neoplasia-metastasis. Naturally occurring phytochemicals are becoming increasingly popular over synthetic drugs for several reasons, including safety, efficacy and easy availability. Nimbolide, a triterpene derived from the leaves and flowers of neem, is widely used in traditional medical practices for treating various human ailments. The neem limonoid exhibits multiple pharmacological effects among which its anticancer activity is the most promising. The preclinical and mechanistic studies carried over the decades have shown that nimbolide inhibits tumorigenesis and metastasis without any toxicity and unwanted side effects. Nimbolide exhibits anticancer activity through selective modulation of multiple cell signaling pathways linked to inflammation, survival, growth, invasion, angiogenesis and metastasis. The present review highlights the current knowledge on molecular targets that contribute to the observed anticancer activity of nimbolide related to (i) inhibition of carcinogenic activation and induction of antioxidant and carcinogen detoxification enzymes, (ii) induction of growth arrest and apoptosis; and (iii) suppression of proinflammatory signaling pathways related to cancer progression. © 2014 Elsevier Ltd.


Satheeshkumar N.,National Institute of Pharmaceutical Education and Research | Shantikumar S.,National Institute of Pharmaceutical Education and Research | Srinivas R.,Indian Institute of Chemical Technology
Journal of Pharmaceutical Analysis | Year: 2014

Pioglitazone is an oral anti-hyperglycemic agent. It is used for the treatment of diabetes mellitus type 2. It selectively stimulates nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-gamma). It was the tenth-best-selling drug in the U.S. in 2008. This article examines published analytical methods reported so far in the literature for the determination of pioglitazone in biological samples and pharmaceutical formulations. They include various techniques like electrochemical methods, spectrophotometry, capillary electrophoresis, high-performance liquid chromatography, liquid chromatography-electrospray ionization-tandem mass spectrometry and high-performance thin layer chromatography. © 2014 Xi'an Jiaotong University.


Kalariya P.D.,National Institute of Pharmaceutical Education and Research | Talluri M.V.N.K.,National Institute of Pharmaceutical Education and Research | Patel P.N.,National Institute of Pharmaceutical Education and Research | Srinivas R.,National Institute of Pharmaceutical Education and Research | Srinivas R.,Indian Institute of Chemical Technology
Journal of Pharmaceutical and Biomedical Analysis | Year: 2015

The present study reports the degradation behavior of a new antidepressant drug, vilazodone, under various stress conditions as per International Conference on Harmonization guidelines (ICH, Q1A(R2). The investigation involved monitoring decomposition of the drug under hydrolytic (acidic, basic and neutral), oxidative, photolytic and thermal stress conditions and identifying degradation products. A rapid, precise, accurate and robust ultra high performance liquid chromatography (UPLC) method has been developed on a Waters CSH Phenyl-Hexyl column (100. mm. ×. 2.1. mm, 1.7. μm) using gradient elution of 10. mM ammonium acetate buffer (pH 5.0) and acetonitrile as mobile phase. The drug was found to be degraded in hydrolytic (acidic and basic) and oxidative conditions, whereas it was stable under neutral hydrolytic, photolytic and thermal stress conditions. The method was extended to quadrupole time-of-flight mass spectrometry (QTOF-MS) for the structural characterization of degradation products. It has been observed that isomeric N-oxide degradation products were formed under oxidative stress condition. The exact location of N-oxidation in the drug was investigated using atmospheric pressure chemical ionization (APCI) due to the formation of characteristic fragment ions. These fragment ions resulted from Meisenheimer rearrangement owing to thermal energy activation at the vaporizer of APCI source. All degradation products were comprehensively characterized by UPLC-ESI-MS/MS and UPLC-APCI-MS experiments. The most probable mechanisms for the formation of degradation products have also been proposed. The method was validated in terms of specificity, linearity, accuracy, precision, and robustness as per ICH guidelines. © 2014 Elsevier B.V.


Srinivas R.,Indian Institute of Chemical Technology | Srinivas R.,University of North Carolina at Chapel Hill | Garu A.,Indian Institute of Chemical Technology | Moku G.,Indian Institute of Chemical Technology | And 2 more authors.
Biomaterials | Year: 2012

Dendritic cells (DCs) pulsed/transduced with tumor-associated or viral antigens have shown promise in combating cancer and infectious diseases. Despite significant progresses, development of a biologically safe DC-based genetic immunization (DNA vaccination) system capable of providing truly long-lasting protective immunity remains a significant scientific challenge. Here we show that immunization with autologous DCs pre-transfected with electrostatic complexes (lipoplexes) of a plasmid DNA encoding melanoma tumor associated antigen and liposomes of two lysinylated cationic amphiphiles with mannose-mimicking quinic and shikimic acid head-groups provides long-lasting (300 days post tumor challenge) protective immunity with significant memory response (more than six months after the second tumor challenge) in more than 80% immunized mice. The presently described non-viral ex vivo DC-transfection system may be exploited in inducing long-lasting immune response in DC-based genetic immunization. © 2012 Elsevier Ltd.


Venkata Mohan S.,Indian Institute of Chemical Technology | Venkata Mohan S.,Academy of Scientific and Innovative Research AcSIR | Devi M.P.,Indian Institute of Chemical Technology | Devi M.P.,Academy of Scientific and Innovative Research AcSIR
Bioresource Technology | Year: 2014

Influence of salinity as a stress factor to harness biodiesel was assessed during dual mode cultivation of microalgae by integrating biomass growth phase (BGP) and salinity induced lipid induction phase (LIP). BGP was evaluated in mixotrophic mode employing nutrients (NPK) and carbon (glucose) source while LIP was operated under stress environment with varying salt concentrations (0, 0.5, 1 and 2. g. NaCl/l). Salinity stress triggered both biomass growth and lipid synthesis in microalgae significantly. BGP showed higher increments in biomass growth (2.55. g/l) while LIP showed higher lipid productivity (1. g. NaCl/l; total/neutral lipid, 23.4/9.2%) than BGP (total/neutral lipid, 15.2/6%). Lower concentrations of salinity showed positive influence on the process while higher concentrations showed marked inhibition. Salinity stress also facilitated in maintaining saturated fatty acid methyl esters in higher amounts which associates with the improved fuel properties. Efficient wastewater treatment was observed during BGP operation indicating the assimilation of carbon/nutrients by microalgae. © 2014 Elsevier Ltd.


Chandra R.,Indian Institute of Chemical Technology | Chandra R.,Academy of Scientific and Innovative Research AcSIR | Rohit M.V.,Indian Institute of Chemical Technology | Swamy Y.V.,Indian Institute of Chemical Technology | Venkata Mohan S.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2014

Critical role of organic carbon supplementation on the lipid synthesis during growth and nutrient deprived stress phase was investigated in present study. Mixotrophic cultivation showed relatively higher biomass productivity at lower carbon loading condition (500. mg. COD/l). Nutrient deprivation induced physiological stress and glucose supplementation with 2000. mg. COD/l supported higher lipid accumulation (26%). Glucose supplementation in mixotrophic growth phase showed distinct influence on biomass growth whereas glucose supplementation in nutrient starvation resulted in higher lipid storage. Compositional variation in FAME profile was observed with respect to saturated fatty acids when operated with increasing glucose concentrations. Mixotrophic mode of cultivation showed remarkable benefits of nutrient removal and organic carbon supplementation influenced greatly on biodiesel production which can be easily scaled up to pilot plant and large scale production facilities. © 2014 Elsevier Ltd.


Pasupuleti S.B.,Academy of Scientific and Innovative Research AcSIR | Sarkar O.,Indian Institute of Chemical Technology | Venkata Mohan S.,Academy of Scientific and Innovative Research AcSIR
International Journal of Hydrogen Energy | Year: 2014

The present account focuses on upscaling of biohydrogen (H2) production at semi-pilot scale bioreactor using composite food waste. Experiments were conducted at different organic load (6, 12, 18, 30, 40, 50 and 66 g COD/l) conditions. H2 production increased with an increasing organic load up to 50 g COD/l (9.67 l/h) followed by 40 g COD/l (6.48 l/h), 30 g COD/l (1.97 l/h), 18 g COD/l (0.90 l/h), 12 g COD/l (0.78 l/h) and 6 g COD/l (0.32 l/h). H2 production was affected by acidification (pH drop to 3.96) at 66 g COD/l operation due to the excess accumulation of soluble metabolites (5696 mg VFA/l). Variation in organic load of food waste influenced the overall hydrogen production efficiency. © 2014 Hydrogen Energy Publications, LLC.


Yadav A.J.S.,Indian Institute of Chemical Technology | Yadav A.J.S.,King Saud University | Mandal S.S.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2011

The enantioselective synthesis of bio-active 5,6-dihydro-α-pyrone, pectinolide A, has been achieved in 10 steps in good overall yield. Of the three stereogenic centres, the C-5/C-6 vic-diol was obtained using diastereo- and enantioselective Brown hydroxyl crotylation, while the C-3' stereocentre was created by Jacobsen hydrolytic kinetic resolution method. © 2011 Elsevier Ltd. All rights reserved.


Yadav J.S.,Indian Institute of Chemical Technology | Yadav J.S.,King Saud University | Rajendar G.,Indian Institute of Chemical Technology
European Journal of Organic Chemistry | Year: 2011

Two aliphatic polyketide natural products, polyrhacitides A and B, have been synthesized in a concise and highly stereoselective manner. The synthesis involved an auxiliary-based acetate aldol reaction to generate the initial stereogenic center and an iterative Wittig reaction, intramolecular oxa-Michael addition, and chelation-controlled reduction reaction as the key steps to generate additional stereocenters. One-pot acid-mediated global deprotection and cyclization reactions shape the final bicyclic lactone core. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Ganguly K.,Indian Institute of Chemical Technology | Sharma A.V.,Indian Institute of Chemical Technology | Reiter R.J.,University of Texas at San Antonio | Swarnakar S.,Indian Institute of Chemical Technology
Journal of Pineal Research | Year: 2010

Matrix metalloproteinase (MMP)-2 is considered as a crucial regulator of angiogenesis, a process of new blood vessel formation. We reported previously that melatonin (N-acetyl-5-methoxy tryptamine), an antioxidant and anti-inflammatory agent, prevents indomethacin-induced gastric ulcers. Herein, we investigated the effect of melatonin on MMP-2-mediated angiogenesis during gastroprotection. Angiogenic properties of melatonin were tested in both rat corneal micropocket assay and in mouse model of indomethacin-induced gastric lesions. Melatonin augmented angiogenesis that was associated with amelioration of MMP-2 expression and activity and, upregulation of vascular endothelial growth factor (VEGF) in rat cornea. Melatonin prevented gastric lesions by promoting angiogenesis via upregulation of VEGF followed by over-expression of MMP-2. Similarly, healing of gastric lesions was associated with early expression of VEGF followed by MMP-2. In addition, upregulation of MMP-2 was parallel to MMP-14 and inverse to tissue inhibitor of metalloprotease (TIMP)-2 expression during gastroprotection. Our data demonstrated that melatonin exerts angiogenesis through MMP-2 and VEGF over-expression during protection and healing of gastric ulcers. This study highlights for the first time a phase-associated regulation of MMP-2 activity in gastric mucosa and an angiogenic action of melatonin to rescue indomethacin-induced gastropathy. © 2010 John Wiley & Sons A/S.


Kumar P.,Indian Institute of Petroleum | Kumar A.,Indian Institute of Petroleum | Sreedhar B.,Indian Institute of Chemical Technology | Sain B.,Indian Institute of Petroleum | And 2 more authors.
Chemistry - A European Journal | Year: 2014

New graphene oxide (GO)-tethered-CoII phthalocyanine complex [CoPc-GO] was synthesized by a stepwise procedure and demonstrated to be an efficient, cost-effective and recyclable photocatalyst for the reduction of carbon dioxide to produce methanol as the main product. The developed GO-immobilized CoPc was characterized by X-ray diffraction (XRD), FTIR, XPS, Raman, diffusion reflection UV/Vis spectroscopy, inductively coupled plasma atomic emission spectroscopy (ICP-AES), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). FTIR, XPS, Raman, UV/Vis and ICP-AES along with elemental analysis data showed that CoII-Pc complex was successfully grafted on GO. The prepared catalyst was used for the photocatalytic reduction of carbon dioxide by using water as a solvent and triethylamine as the sacrificial donor. Methanol was obtained as the major reaction product along with the formation of minor amount of CO (0.82%). It was found that GO-grafted CoPc exhibited higher photocatalytic activity than homogeneous CoPc, as well as GO, and showed good recoverability without significant leaching during the reaction. Quantitative determination of methanol was done by GC flame-ionization detector (FID), and verification of product was done by NMR spectroscopy. The yield of methanol after 48 h of reaction by using GO-CoPc catalyst in the presence of sacrificial donor triethylamine was found to be 3781.8881 μmolg-1cat., and the conversion rate was found to be 78.7893 μmolg-1cat.h-1. After the photoreduction experiment, the catalyst was easily recovered by filtration and reused for the subsequent recycling experiment without significant change in the catalytic efficiency. Very photoactive! Cobalt phthalocyanine grafted to the chemically functionalized graphene oxide was found to be an efficient heterogeneous visible-light-induced photoredox catalyst for the photoreduction of carbon dioxide to methanol in a very good yield. The developed photocatalyst exhibited superior activity compared with the existing photocatalytic systems and gave methanol as the major reaction product (see scheme). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sau S.,Indian Institute of Chemical Technology | Banerjee R.,Indian Institute of Chemical Technology | Banerjee R.,Academy of Scientific and Innovative Research AcSIR
European Journal of Medicinal Chemistry | Year: 2014

Dexamethasone (Dex) is one of the highly potent synthetic glucocorticoids. It exhibits prominent anti-inflammatory but moderate anti-proliferative activities. It is widely used along side chemotherapy to alleviate toxic side effects. Additionally, Dex is also a potent inducer of gluconeogenesis. However, its overuse critically desensitizes cells against chemotherapy. Herein, we report on the development of a new class of cationic lipid-Dex conjugates in which the C-8 carbon chain analogue (DX8) exhibited glucocorticoid receptor (GR)-mediated, caspase-3-assisted, cancer cell-selective anti-proliferative activity. Melanoma tumors in DX8-treated mice exhibited significantly reduced tumor aggressiveness with respect to tumors in Dex-treated mice. Tumor lysates prepared from DX8-treated group showed elevated levels of p53. DX8-treated cancer cells showed clear degradation of kinase JAK3/STAT3 protein levels. Additionally, DX8-treatment decreased the level of VEGFR2 in tumor-endothelial cells implying DX8's anti-proliferative roles in both tumor cells and tumor neovascular cells. Collectively, our results demonstrate potent anti-angiogenic, and selective JAK3/STAT3 down-regulating anticancer characteristics of DX8, a new dexamethasone-based antitumor molecule. © 2014 Elsevier Masson SAS. All rights reserved.


Yadav J.S.,Indian Institute of Chemical Technology | Yadav J.S.,King Saud University | Pattanayak M.R.,Indian Institute of Chemical Technology | Pattanayak M.R.,University of Hyderabad | And 2 more authors.
Organic Letters | Year: 2011

The formal total synthesis of leucascandrolide A has been achieved in 20 steps from a known epoxide with an overall yield of 11.5% following a recently developed strategy for the construction of trans-2,6-disubstituted-3,4- dihydropyrans and a Lewis acid catalyzed intramolecular Prins-cyclization of an aldehydic homoallylic alcohol to generate the tetrahydropyran ring with three stereogenic centers and macrocycle concomitantly. © 2011 American Chemical Society.


Kumaraswamy G.,Indian Institute of Chemical Technology | Kumaraswamy G.,Academy of Scientific and Innovative Research AcSIR | Raju R.,Indian Institute of Chemical Technology
Advanced Synthesis and Catalysis | Year: 2014

Aerobic dehydrogenative sulfenylation of H-phosphonites, and phosphine oxides with aryl/alkylsulfonyl hydrazides catalyzed by a sub-stoichiometric amount of copper iodide has been accomplished. This protocol is compatible with functional groups, and results in various thiophosphate derivatives in good to high yields. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Venkata Subhash G.,Academy of Scientific and Innovative Research AcSIR | Venkata Subhash G.,Indian Institute of Chemical Technology | Venkata Mohan S.,Academy of Scientific and Innovative Research AcSIR | Venkata Mohan S.,Indian Institute of Chemical Technology
Fuel | Year: 2014

The specific effects of chemical and physical factors on lipid synthesis of isolated Aspergillus awamori (MTCC11639) was investigated with the final aim of producing biodiesel. Design of experimental methodology (DOE) was employed to understand the fungal lipid synthesis with response to the selected factors. An orthogonal array (OA) was designed to evaluate the influence of eight factors using three levels of factor (21 × 37) variation with a L18 experimental matrix. Among the selected factors, pH influenced the lipid production substantially (41.6%), followed by glucose (16.3%) and incubation temperature (4.3%). Interaction of proteins with nitrates showed highest severity index (SI, 85.1%), while NaCl with incubation time documented lowest SI (20.0%). Validation experiments with the obtained optimum conditions showed improved lipid productivity of 31%, along with 90% substrate degradation. Composition of fatty acid methyl esters (FAME) of fungal lipids showed higher saturated fatty acid (SFA) than unsaturated fatty acids (USFA). © 2013 Elsevier Ltd. All rights reserved.


Yadav J.S.,Indian Institute of Chemical Technology | Yadav J.S.,King Saud University | Haldar A.,Indian Institute of Chemical Technology | Maity T.,Indian Institute of Chemical Technology
European Journal of Organic Chemistry | Year: 2013

A highly stereoselective synthesis of the C1-C16 macrolactone core segment of the cytotoxic macrolide lyngbyaloside B has been achieved. The synthetic strategy involved aldol additions of chlorotitanium enolates of N-propionyl thiazolidinethiones to achieve non-Evans as well as Evans syn-propionate aldol reactions as the key steps to establish four of the seven stereogenic centres present in the macrolactone core (2). The C7 hydroxy group and tertiary hydroxy group at C13 were introduced by using different strategies for the regioselective opening of epoxides generated by Katsuki-Sharpless asymmetric epoxidation. A crucial intermolecular acyl ketene trapping by the tertiary alcohol at C13, and a subsequent ring-closing metethesis reaction served to unite the northern and southern hemisphere subunits to construct the macrolactone core (2). A highly stereoselective synthesis of the C1-C16 macrolactone core segment of the cytotoxic macrolide lyngbyaloside B has been achieved. Intermolecular acyl ketene trapping by the tertiary alcohol at C13, and a subsequent ring-closing metathesis reaction served to unite the northern and southern hemisphere subunits to construct the macrolactone core. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Sydulu Singu B.,Osmania University | Srinivasan P.,Indian Institute of Chemical Technology | Pabba S.,Osmania University
Journal of the Electrochemical Society | Year: 2012

Benzoyl peroxide is used as an oxidant for the oxidation of aniline to polyaniline salt via interfacial polymerization pathway (IP) for the first time in presence of sodium lauryl sulfate as emulsifier and 5-sulfophthalic acid as protonic acid. Polyaniline salt is also synthesized by interfacial polymerization using higher amount of reactants and emulsion polymerization pathways. Polyaniline salts are characterized by FT-IR, XRD and SEM. This polymerization process gives polyaniline salt containing dual dopants (5-sulfophthalic acid and dodecyl hydrogen sulfate) i.e. small and long chain molecules on polyaniline. Polyaniline salt prepared by emulsion polymerization pathway (EP) shows nanowires with a higher yield (0.98 g) compared to that of the interfacial polymerization (IP) pathway (0.73 g), which also shows nanowires morphology. However, very less yield (0.2 g) is obtained by the interfacial polymerization pathway using higher concentration of reactants (IP-H), which shows nanotubes. Polyaniline salt is mixed with Multi-walled carbon nanotube (MWCNTs) material, made electrode with stainless steel mesh and this electrode is used for the study of symmetric supercapacitor cell. Electrochemical performance is found by cyclic voltammetry, charge-discharge and electrochemical impedance spectroscopy. The results clearly indicate that the polyaniline salt containing dual dopants is a very good material for supercapacitor. © 2011 The Electrochemical Society.


Albaseer S.S.,Institute of Chemical Technology | Mukkanti K.,Institute of Chemical Technology | Rao R.N.,Indian Institute of Chemical Technology | Swamy Y.V.,Indian Institute of Chemical Technology
TrAC - Trends in Analytical Chemistry | Year: 2011

Sample handling and preservation methods of environmental samples of synthetic pyrethroids (SPs) are very important and must be controlled to maintain sample integrity during analytical determinations. However, published literature has treated this issue only partly, and, in many instances, with contradictory conclusions.The tendency of SPs to adsorb - to varying degrees under different conditions - to surfaces and solid particulates with which they come in contact may be responsible for this situation. It has become evident that SPs discharged to water bodies are present mainly in the adsorbed state, and that affects their bioavailability and the reliability of analytical results. Refrigeration and storage in the dark are prerequisites for stabilization of SPs in environmental samples.Several other factors that contribute to SPs instability include:. (1) matrix composition;. (2) container material; and,. (3) sample acidity.Sample agitation prior to analysis may be useful to reduce losses due to adsorption. There are several chemical reagents that inhibit the degradative processes of SPs, but the efficiency of preservation depends - to a large extent - on the characteristics of sample matrix.This article reviews various aspects related to preservation of SPs and puts forward a preliminary guideline for proper practice during sampling, storage and sample preparation of SPs. © 2011 Elsevier Ltd.


Murali R.S.,Indian Institute of Chemical Technology | Sankarshana T.,Osmania University | Sridhar S.,Indian Institute of Chemical Technology
Separation and Purification Reviews | Year: 2013

Separation of air to produce enriched nitrogen and oxygen has been of great significance to the chemical industry. Membrane-based gas permeation process has gained due importance over conventional methods such as cryogenic distillation, solid adsorption and solvent absorption, because it is economical, compact in size, modular in configuration and has the capacity to offer low specific power consumption. Typical applications of the membrane-produced nitrogen include blanketing, purging, inerting and underbalanced drilling, while the oxygen-enriched air is mainly used for combustion enhancement in furnaces, fuel cells, medical respiration and undersea breathing. Most membranes used in air separation are made of solid polymers. This review seeks to define the current technological factors that govern the field of application of polymeric membranes for the separation of air. Potential membrane materials, physical and chemical modifications of membranes for further research in this area are discussed. © 2013 Taylor and Francis Group, LLC.


Begum G.,Osmania University | Begum G.,Indian Institute of Chemical Technology
Fish Physiology and Biochemistry | Year: 2011

The acute effect of carbofuran, a carbamate insecticide, was studied on adenosine triphosphatase enzymes in gill, kidney, liver and muscle tissues of a food fish, Clarias batrachus. Glycogen and glycogen phosphorylase were investigated in gill and kidney only. Thirty-six fish were exposed to sublethal concentration (7.6 mg/L) for 6 days. After 6 days, 18 fish were released into freshwater in order to study the recovery response. Eighteen fish were kept in clean water as control. Tissues were isolated from control, exposed and recovery fish at the end of 1, 3 and 6 days and used for the assay of enzymes. Total ATPase was inhibited in kidney and muscle tissues throughout the exposure period, whereas branchial and hepatic tissues showed initial induction followed by inhibition. Na+-K+ ATPase activity was induced in gill till day 3, whereas in other tissues inhibition was throughout the exposure period. Mg+2 ATPase activity was inhibited in all tissues except liver. When the fish were released into freshwater, liver recovered almost to control values and other tissues showed organ-specific response. Glycogen content of gill increased initially followed by decrease, and in kidney initial decrease was noted. The recovery response was more in kidney than in gill. Induction in the activity of glycogen phosphorylases was observed in kidney, whereas gill tissue showed mixed response. Recovery was not observed in phosphorylases. Thus, the results of the present study demonstrated the acute effect of carbofuran on a food fish and organ-specific recovery response to insecticidal treatment. © 2010 Springer Science+Business Media B.V.


Palaniappan S.,Indian Institute of Chemical Technology | Sydulu S.B.,Osmania University | Srinivas P.,Osmania University
Journal of Applied Polymer Science | Year: 2010

Copolymer of aniline and pyrrole was synthesized by inverted emulsion polymerization method by oxidizing aniline and pyrrole using benzoyl peroxide in presence of sodium laurylsulphate surfactant and p-toluenesulphonic acid. Copolymer samples were characterized by infrared, X-ray diffraction and scanning electron microscopic techniques and compared their properties with the corresponding homopolymers. The optimum reaction conditions for the preparation of copolymer with reasonably good yield (1.72 g) and conductivity (7.3 × 10-2 S/cm) were established. The synthesis procedure was extended to prepare copolymer samples using various protonic acids. Electrochemical characterization such as cyclic voltammetry, charge-discharge and impedance were carried out on symmetrical supercapacitor cell consists of poly(aniline-co- pyrrole)-p-toluenesulfonic acid salt, wherein, the copolymer salt was synthesized using equal amount of aniline and pyrrole monomers. The values of specific capacitance, energy and power densities for poly- (aniline-co-pyrrole)- p-toluenesulfonic acid system (PANIPPy) were calculated from charge-discharge studies and are found to be 21 F/g, 5.7 Wh/Kg and 100 W/Kg respectively. Impedance analysis showed specific capacitance value (57 F/g) at 0.01 Hz at 0.22 V. Among the copolymer salts, copolymer prepared with sulfuric acid showed higher capacitance (66 F/g). © 2009 Wiley Periodicals, Inc.


Surya Murali R.,Indian Institute of Chemical Technology | Sridhar S.,Indian Institute of Chemical Technology | Sankarshana T.,Osmania University | Ravikumar Y.V.L.,Osmania University
Industrial and Engineering Chemistry Research | Year: 2010

Incorporation of multiwalled carbon nanotubes (MWNT) on the gas permeation properties of H2, CO2, O2, and N2 gases in poly(ether-block-amide) (Pebax-1657) membrane has been investigated. Pebax-1657 was dissolved in the ethanol-water mixture and cast on an ultraporous polyethersulfone substrate followed by complete solvent evaporation. Nanocomposite membranes were prepared by dispersion of MWNT in concentrations of 0-5% of polymer weight in the Pebax solutions with sonication for 2 h to ensure uniformity. Cross-linking was carried out in hexane medium using 2,4-toluylene diisocyanate (TDI). The permeabilities of pure gases were measured at room temperature, and the ideal selectivities were determined at pressures varying from 1-3 MPa using an indigenously built high-pressure gas separation manifold. For neat Pebax membrane, high permeabilities of 55.8 and 32.1 barrers were observed for CO2 and H2 gases, respectively, whereas that of N2 was as low as 1.4 barrers. The selectivity of cross-linked 2% MWNT Pebax membrane was enhanced from 83.2 to 162 with increasing feed pressure (1-3 MPa) for the CO2/N2 gas pair, whereas the corresponding values for H2/N2 and O2/N 2 systems were found to be in the range 82.5-90 and 7.1-6.8, respectively. The membranes were characterized by scanning electron microscopy (SEM) to study surface and cross-sectional morphologies. Fourier transform infrared (FT-IR), wide-angle X-ray diffraction (WAXD), and ion exchange capacity (IEC) studies were carried out to determine the effect of MWNT incorporation on intermolecular interactions, degree of crystallinity, and extent of cross-linking, respectively. Fractional free volume (FFV) calculations based on density measurements were conducted along with water sorption studies to explain permeation behavior. The use of modified block copolymer membranes provides a means for separation of CO2 from N2 in power plants, H2 recycle from ammonia purge gas, O2 enrichment from air for medical applications, and CO2 removal from water-gas shift reaction to improve H2 yield. © 2010 American Chemical Society.


Roy A.,Vidyasagar University | Maiti M.,Vidyasagar University | Nayak R.R.,Indian Institute of Chemical Technology | Roy S.,Vidyasagar University
Journal of Materials Chemistry B | Year: 2013

The present study offers the demonstration and rational design of two synthesized single chain pyridyl carboxylic acid (nicotinic acid) based amphiphilic gelators named the sodium salt of 2-dodecylpyridine-5-carboxylic acid (SDDPC) and the sodium salt of [2-dodecylpyridine-5-carboxylic]glycine (SDDPCG). The gelation abilities were tested in a series of organic solvents, by a number of physical methods including X-ray diffraction, FTIR spectroscopy, rheology, DSC, optical and electron microscopy. The minimum gelation concentration and gelation number of the gelators in different solvents were determined. No gelation was observed when pure solvents were employed. The gelation properties of these two compounds found that the gelation depends on H-bonding of the amide linkage. X-ray diffraction study indicates the presence of two recognizable morphologies for SDDPC in a gel-emulsion, whereas for SDDPCG a single type of aggregate is predominant. FTIR spectra suggest that the presence of intermolecular hydrogen bonding facilitates the gelation process. Rheological measurements demonstrated that the gel-emulsions are mechanically stable and exhibit typical viscoelastic properties. Optical microscopy images show a network structure in the gel phase and a fibril structure in the xerogel. SEM images confirmed the presence of network as well as a flex-like thick fibrous network for both the amphiphiles, forming three dimensional (3-D) networks. Both the gelators showed a remarkable response toward external pH. The gel-emulsions were used in the controlled and/or pH triggered release of entrapped (within the gel-emulsions) vitamin B12 at different pHs. © 2013 The Royal Society of Chemistry.


Anand N.,Indian Institute of Chemical Technology | Reddy K.H.P.,Indian Institute of Chemical Technology | Satyanarayana T.,Osmania University | Rao K.S.R.,Indian Institute of Chemical Technology | Burri D.R.,Indian Institute of Chemical Technology
Catalysis Science and Technology | Year: 2012

A magnetically recoverable iron oxide (γ-Fe 2O 3) nanocatalyst (MRIONC) has been synthesized and characterized by XRD, FT-IR, XPS and TEM techniques and it was found that MRIONC is a new and highly efficient green catalyst for the synthesis of 2-phenylquinazolines from 2-aminoarylketones and benzyl amines under solvent free conditions, and in addition MRIONC could be easily recovered by a simple magnetic separation and recycled at least 5 times without significant loss in catalytic activity. © 2012 The Royal Society of Chemistry.


Pooja D.,Indian Institute of Chemical Technology | Panyaram S.,Indian Institute of Chemical Technology | Kulhari H.,Indian Institute of Chemical Technology | Rachamalla S.S.,Osmania University | Sistla R.,Indian Institute of Chemical Technology
Carbohydrate Polymers | Year: 2014

Xanthan gum (XG) has been widely used in food, pharmaceutical and cosmetic industries. In the present study, we explored the potential of XG in the synthesis of gold nanoparticle. XG was used as both reducing and stabilizing agent. The effect of various formulation and process variables such as temperature, reaction time, gum concentration, gum volume and gold concentration, in GNP preparation was determined. The XG stabilized, rubey-red XGNP were obtained with 5 ml of XG aqueous solution (1.5 mg/ml). The optimum temperature was 80 °C whereas the reaction time was 3 h. The optimized nanoparticles were also investigated as drug delivery carrier for doxorubicin hydrochloride. DOX loaded gold nanoparticles (DXGP) were characterized by dynamic light scattering, TEM, FTIR, and DSC analysis. The synthesized nanoparticle showed mean particle size of 15-20 nm and zeta potential -29.1 mV. The colloidal stability of DXGP was studied under different conditions of pH, electrolytes and serum. Nanoparticles were found to be stable at pH range between pH 5-9 and NaCl concentration up to 0.5 M. In serum, nanoparticles showed significant stability up to 24 h. During toxicity studies, nanoparticles were found biocompatible and non-toxic. Compared with free DOX, DXGP displayed 3 times more cytotoxicity in A549 cells. In conclusion, this study provided an insight to synthesize GNP without using harsh chemicals. © 2014 Elsevier Ltd.


Jagadeeswaraiah K.,Indian Institute of Chemical Technology | Kumar C.R.,Indian Institute of Chemical Technology | Prasad P.S.S.,Indian Institute of Chemical Technology | Loridant S.,CNRS Research on Catalysis and Environment in Lyon | Lingaiah N.,Indian Institute of Chemical Technology
Applied Catalysis A: General | Year: 2014

Tin-tungsten mixed oxide catalysts with varying their mole ratio were prepared by co-precipitation method. The catalysts physico-chemical properties were derived from FT-infrared, Laser Raman, X-ray diffraction, UV-Vis DRS, BET surface area and temperature-programmed desorption of NH3. The catalysts activities were evaluated for the synthesis of glycerol carbonate from glycerol and urea. The activity results showed that Sn-W mixed oxide catalysts are highly active for selective formation of glycerol carbonate. Sn-W catalyst with 2:1 molar ratio exhibited about 52% of glycerol conversion with >95% selectivity towards glycerol carbonate. The active catalyst was subjected to calcination at different temperatures and evaluated for their activity in glycerol carbonate synthesis. The activity of the catalysts depends on mole ratio of Sn/W and treatment temperature which are influencing the surface-structural characteristics of the catalysts. Different reaction parameters such as glycerol to urea molar ratio, reaction temperature and catalyst loading were studied and optimum conditions were established. The catalysts showed consistent activity upon repeated use. © 2013 Elsevier B.V. All rights reserved.


Harini M.,Indian Institute of Technology Bombay | Adhikari J.,Indian Institute of Technology Bombay | Rani K.Y.,Indian Institute of Chemical Technology
Industrial and Engineering Chemistry Research | Year: 2013

This paper provides a review of the available literature on computational schemes for rational solvent design, with a focus on solvent extraction and crystallization (the two most common unit operations) in pharmaceutical industry. The computer-aided design of solvents is important as a cost-effective tool, especially with the regular development of new pharmaceutical molecules. Also, there is a need to minimize the amount and the number of solvents used with regard to environmental, health, and toxicological concerns. This review covers the properties of interest and the predictive methods for estimation of these properties in solvent design including the group contribution based methods, quantitative structure property prediction methods and molecular modeling methods. In addition, the various optimization approaches for rational solvent design such as outer approximation, branch and bound, simulated annealing, and genetic algorithm are also discussed. © 2013 American Chemical Society.

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