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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.


Bhattacharya P.,Indian Institute of Chemical Technology
Revista da Sociedade Brasileira de Medicina Tropical | Year: 2013

Visceral leishmaniasis (VL) or kala-azar, a disseminated infection of the lymphoreticular system of the body, is marked by severe defect in immune system of the host. Successful cure of VL depends on the immune status of the host in combination with the effects of the antileishmanial drugs. The rationale approach towards eradication of this disease would be to potentiate the immune functioning of the host in addition to parasite killing. This review deals with different aspects of adaptive and innate immune responses and explores their role in protection or pathogenesis of VL. IL-10 has emerged as the principal cytokine responsible for disease pathogenesis, although evidences regarding its source during active VL remain inconclusive. On the other hand, IFNγ,under the influence of IL-12, is mostly correlated with healing of the disease. Chemokines are important in mounting cell-mediated immune response as they can prevent parasite invasion in association with cytokines. Different types of T cells like CD4, CD8 and NK T cells also contribute to the immunology of this disease. In spite of conflicting reports, the role of regulatory T cells in VL pathogenesis is important. Recently discovered Th17 subset and its different members have been reported to perform diverse functions in the course of VL and leishmaniasis as a whole. Innate immune responses, depending on the cell types, are essential in early parasite detection and subsequent development of an efficient NK cell response. Immunotherapy targeting IL-10 could be looked upon as an interesting option for the treatment of VL.


Tejeswararao D.,Indian Institute of Chemical Technology
Journal of the Chilean Chemical Society | Year: 2016

The acidic ionic liquid, 1-(4-sulfonic acid) butyl-3-methylimidazolium hydrogen sulfate [MimC4SO3H]HSO4 catalyzed two-component condensation reaction of phenacyl bromide and o-phenylenediamine to afford corresponding quinoxaline derivatives. The inexpensive and non-toxic ionic liquids can be reused several times without any perceptible loss of their activities. © 2016, Sociedad Chilena de Quimica. 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.


The insecticidal activity of yellow flamboyant, Peltophorum pterocarpum (DC.) Heyne. floral extract against the rice weevil, Sitophilus oryzae (Coleoptera: Curculionidae) was evaluated by using contact and fumigant bioassays. The potential insecticidal compound isolated from the P. pterocarpum was Sitosterol-β-D-glucopyranoside tetraacetate. The LC50 values of the Sitosterol-β-D-glucopyranoside tetra acetate in contact and fumigation mode were observed as 27.16 and 66.54 respectively. Bergenin is reported earlier from this plant however, other compounds isolated Quercetin-3-O-rutinoside and Myricetin-3-O-galactoside along with insecticidal compound Sitosterol–β-D-glucopyranoside tetraacetate for the first time from the Peltophorum pterocarpum. © 2014, JBiopest. All rights reserved.


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.


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.


Patil N.T.,Indian Institute of Chemical Technology
Angewandte Chemie - International Edition | Year: 2011

A co-op: Recent examples on cooperative catalysis, involving metals (M) and N-heterocyclic carbenes (NHCs), delivered products with high enantioselectivity (see scheme). Such products are not possible to obtain by using either of the catalysts individually. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


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.


Rani K.Y.,Indian Institute of Chemical Technology
Journal of Process Control | Year: 2011

A novel Sensitivity Compensating Control (SCC) approach is proposed in a data-driven model based platform and combined with an Extended External Reset Feedback (EERF) method to handle sensitivity, input saturation, and accurate process model requirement problems associated with application of Generic Model Control (GMC). Two versions of Adaptive GMC (AGMC) are proposed using linear-in-parameters time-series models with time-varying parameters for higher relative degree systems, and are used in the formulation of SCC and EERF approaches. The steps involved in the proposed approach consist of defining a new process, control law and set point such that the determined control action drives the original process to its desired set point. The performance of the proposed control algorithms is illustrated by application to a benchmark multi-product polymerization reactor control challenge problem. The proposed approaches are applicable to chemical engineering systems exhibiting input sensitivity. © 2011 Elsevier Ltd.


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.


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.


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.


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.


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.


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.


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.


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.


Anusha P.T.,University of Hyderabad | Swain D.,University of Hyderabad | Hamad S.,University of Hyderabad | Giribabu L.,Indian Institute of Chemical Technology | And 3 more authors.
Journal of Physical Chemistry C | Year: 2012

Ultrafast nonlinear optical (NLO) properties of four novel Corroles in the visible spectral range (660.800 nm) were evaluated using picosecond Z-scan technique. Ultrafast excited state dynamics have also been appraised with picosecond (ps) and femtosecond (fs) degenerate pump.probe techniques using excitation wavelengths of 800 and 600 nm, respectively. The excitation by 800 nm photons resulted in two-photon absorption at adequately high peak intensities, thereby facilitating the access to higher excited states (S n). The nonradiative relaxation mechanisms from these states, reflected in the pump.probe data, consisted of doubleexponential decay with a slow component in the range of 54.277 ps and faster component in the range of 2.0 to 2.5 ps. When excited with 600 nm photons (unfocused), photoinduced absorption was observed with the first excited state S 1 being populated, and as a consequence single decay was observed in the data of all molecules studied. These retrieved lifetimes were analogous to those obtained with picosecond pump.probe data. The long lifetime is attributed to nonradiative decay from the S 1 state with possible contribution from triplet states, whereas the shorter lifetime is attributed to the internal conversion (S 2 to S 1 *), followed by vibrational relaxation (S 1 * to S 1) processes. Time-resolved fluorescence lifetime measurements revealed the magnitude of radiative lifetimes to be in the nanosecond regime. NLO coefficients were evaluated from the Z-scan data at wavelengths of 660, 680, 700, 740, and 800 nm. Large two-photon absorption coefficients (β)/cross-sections (σ 2) at 740 nm/680 nm were recorded for these molecules, making them apposite for applications such as two-photon induced photodynamic therapy and lithography. Figure of merit, T, was <1 for all molecules at 740 and 800 nm, suggesting that these molecules find use in photonic device applications. © 2012 American Chemical Society.


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.


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.


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.


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.


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.


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.


Ramesh P.,Indian Institute of Chemical Technology
Synthesis (Germany) | Year: 2016

A concise stereoselective total synthesis of the naturally occurring styryl lactone 8-methoxygoniodiol in five simple steps from readily available inexpensive trans-cinnamaldehyde is described. The efficient synthesis features a successful protecting-group-free strategy, with desirable step- and atom-economy. The synthetic strategy relies on a Maruoka asymmetric allylation, an epoxidation, a ring-closing metathesis, and a stereoselective epoxide ring opening as key steps. Copyright © 2016, Georg Thieme Verlag. All rights reserved.


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.


Hamad S.,University of Hyderabad | Tewari S.P.,University of Hyderabad | Giribabu L.,Indian Institute of Chemical Technology | Rao S.V.,University of Hyderabad
Journal of Porphyrins and Phthalocyanines | Year: 2012

We present our results from the experimental and modeling studies of picosecond (ps) and femtosecond (fs) nonlinearities of two novel corroles (a) tritolyl corrole (TTC) (b) triphenyl corrole (TPC) using the Z-scan technique. Both open and closed aperture Z-scan curves were recorded with ∼2 ps/∼40 fs laser pulses at a wavelength of 800 nm and nonlinear optical coefficients were extracted for both studies. Both the molecules possessed negative nonlinear refractive index (n 2) as revealed by signature of the closed aperture data in both (ps and fs) time domains. Picosecond nonlinear absorption data of TPC obtained at a concentration of 5 × 10 -4 M demonstrated complex behavior with switching from reverse saturable absorption (RSA) within saturable absorption (SA) at lower peak intensities to RSA at higher peak intensities. TTC data recorded at the similar concentration exhibited saturable absorption (SA) type of behavior at lower peak intensities to switching from RSA with in SA at higher peak intensities. At a concentration of 2.5 × 10 -4 M, the ps open aperture data at higher peak intensities illustrated effective three-photon absorption (3PA) for both the molecules. We also report the picosecond spectral dependent Z-scan studies performed at 680 nm, 700 nm, and 740 nm. Nonlinear absorption and refraction of both the samples at these three wavelengths were studied in detail. Femtosecond nonlinear absorption data of TPC and TTC demonstrated the behavior of saturable absorption (SA) at a concentration of 1 × 10 -3 M. Solvent contribution to the nonlinearity was also identified. We have also evaluated the sign and magnitude of third order nonlinearity. We discuss the nonlinear optical performance of these organic molecules. © 2012 World Scientific Publishing Company.


Bal Sydulu S.,Osmania University | Palaniappan S.,Indian Institute of Chemical Technology | Palaniappan S.,A+ Network | Srinivas P.,Osmania University
Electrochimica Acta | Year: 2013

Long chain protonic acid (dodecylhydrogen sulfate-DHS) along with small molecule acid (sulfuric acid-H2SO4) was introduced as dopants in polyaniline salt (PANI-H2SO4-DHS), hereafter referred as PANI, via aqueous/emulsion polymerization pathway of aniline. Polyaniline salt-acetylene black composites (PANI-AB) were prepared in one-step via aqueous/emulsion polymerization pathway using various amounts of acetylene black (AB). Formation of PANI and PANI-AB was confirmed from infrared and X-ray diffraction patterns. The highest conductivity obtained for PANI-AB composite was 6.2 S cm-1, which is slightly higher than that of PANI (1.3 S cm-1). PANI prepared by aqueous polymerization pathway showed nano fibres with diameter of 10-30 nm. Use of 5 wt% of AB with respect to the amount of aniline used in the polymerization reaction of aniline, PANI-AB showed spheres covered nano fibres with high porosity. By increasing the amount of AB to 10 wt%, nano fibres are getting closure, which reduced the porosity. Further increase in the amount of AB to 15 wt%, nano fibres disappear. PANI and PANI-AB were used as electrode materials in symmetric supercapacitor cell. Specific capacitance, Energy and power densities of PANI-AB composite were found to be 157.6 F g-1., 15.7 Wh kg-1 and 600 W kg-1 respectively. © 2013 Elsevier Ltd. All rights reserved.


Rama Mohan S.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2016

Looming energy crisis, climate change concerns coupled with decreasing fossil fuel resources has garnered significant global attention toward development of alternative, renewable, carbon-neutral and eco-friendly fuels to fulfil burgeoning energy demands. Waste utilization and its management are being pursued with renewed interest due to the gamut of biobased products it can offer apart from providing enough energy to meet a major fraction of the world's energy demand. Biorefining is the sustainable processing of biomass into a spectrum of marketable products and energy. Integrating all components of waste treatment culminating into biobased products and energy recovery in a single integrated waste biorefinery is self sufficient, highly sustainable and is very beneficial. Designing systematic innovation policies are essential for development and commercialization of new technologies in this important futuristic research area. This communication explores Innovation Policy Road Mapping (IPRM) methodology available in the literature and applies it to design integrated waste biorefinery. © 2016 Elsevier Ltd.


Chen W.,Chinese Academy of Sciences | Yan L.,Chinese Academy of Sciences | Bangal P.R.,Indian Institute of Chemical Technology
Carbon | Year: 2010

Rapid and mild thermal reduction of graphene oxide (GO) to graphene was achieved with the assistance of microwaves in a mixed solution of N,N-dimethylacetamide and water (DMAc/H2O). The mixed solution works as both a solvent for the produced graphene and a medium to control the temperature of the reactive system up to 165 °C. Fourier transform infrared spectrometry, X-ray diffraction, atomic force microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, and thermogravimetric analysis confirmed the formation of graphene under this mild thermal reduction condition. The reduction time is found to be in the scale of minutes. The as-prepared graphene can be well dispersed in DMAc to form an organic suspension, and the suspension is stable for months at room temperature. The conductivity of graphene paper prepared by the microwave reduced product is about 104 times than that of GO paper. © 2009 Elsevier Ltd. All rights reserved.


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.


Rao R.N.,Indian Institute of Chemical Technology
Expert Review of Proteomics | Year: 2014

Dried blood spots (DBS), a micro blood sampling technique, has recently gained interest in drug discovery and development due to its inherent advantages over the conventional whole blood, plasma or serum sample collection. Since the regulatory authorities have agreed to the use of blood as an acceptable biological matrix for drug exposure measurements, its applications have been extended not only to therapeutic drug monitoring but also to toxicokinetic and pharmacokinetic studies. The pharmaceutical industry is keen to promote DBS as a prominent tool in bioanalytical applications due to the financial, ethical and organizational issues involved in clinical trials. This could be accomplished due to the latest advances in modern analytical technology, particularly liquid chromatography-mass spectrometry. The present review discusses some of the emerging liquid chromatography-mass spectrometry technologies in improving DBS analysis for its innovative applications in the development of new drugs. © 2014 Informa UK, Ltd.


Context: Three-phase partitioning (TPP), a unique technique which has been explored for protein separation, was used for extraction of trichosanthin (TCS). Objective: TPP was used to optimize the TCS extraction and to determine its anticancer activity. Materials and methods: The process consists of the simultaneous addition of t-butanol and ammonium sulfate to the aqueous slurry of Trichosanthes kirilowii Maxim (Cucurbitaceae) root powder. The extraction of TCS was optimized with respect to the concentration of ammonium sulfate loading, the ratio of t-butanol to slurry, extraction time and pH. The anticancer activity was performed using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay in vitro. Results: The extraction time with this technique is lower in comparison to conventional solvent extraction. The optimized protocol resulted in maximum recovery of 98.68% (w/w) protein within 1h. The in vitro cytotoxic activity of the TCS was evaluated against HepG2 and WRL 68 cancer cell line and results showed that TCS possesses quite highly significant anticancer activity having IC50 values of 10.38 and 15.45μmol/l, respectively, comparable to standard drugs. Conclusion: This framework is utilized as a basis for optimization for protein separation using TPP technique which is economical and eco-friendly. © 2014 Informa Healthcare USA, Inc. All rights reserved.


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.


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.


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.


The inability of sodium antimony gluconate (SAG)-unresponsive kala-azar patients to clear Leishmania donovani (LD) infection despite SAG therapy is partly due to an ill-defined immune-dysfunction. Since dendritic cells (DCs) typically initiate anti-leishmanial immunity, a role for DCs in aberrant LD clearance was investigated. Accordingly, regulation of SAG-induced activation of murine DCs following infection with LD isolates exhibiting two distinct phenotypes such as antimony-resistant (Sb(R)LD) and antimony-sensitive (Sb(S)LD) was compared in vitro. Unlike Sb(S)LD, infection of DCs with Sb(R)LD induced more IL-10 production and inhibited SAG-induced secretion of proinflammatory cytokines, up-regulation of co-stimulatory molecules and leishmanicidal effects. Sb(R)LD inhibited these effects of SAG by blocking activation of PI3K/AKT and NF-kappaB pathways. In contrast, Sb(S)LD failed to block activation of SAG (20 microg/ml)-induced PI3K/AKT pathway; which continued to stimulate NF-kappaB signaling, induce leishmanicidal effects and promote DC activation. Notably, prolonged incubation of DCs with Sb(S)LD also inhibited SAG (20 microg/ml)-induced activation of PI3K/AKT and NF-kappaB pathways and leishmanicidal effects, which was restored by increasing the dose of SAG to 40 microg/ml. In contrast, Sb(R)LD inhibited these SAG-induced events regardless of duration of DC exposure to Sb(R)LD or dose of SAG. Interestingly, the inhibitory effects of isogenic Sb(S)LD expressing ATP-binding cassette (ABC) transporter MRPA on SAG-induced leishmanicidal effects mimicked that of Sb(R)LD to some extent, although antimony resistance in clinical LD isolates is known to be multifactorial. Furthermore, NF-kappaB was found to transcriptionally regulate expression of murine gammaglutamylcysteine synthetase heavy-chain (mgammaGCS(hc)) gene, presumably an important regulator of antimony resistance. Importantly, Sb(R)LD but not Sb(S)LD blocked SAG-induced mgammaGCS expression in DCs by preventing NF-kappaB binding to the mgammaGCS(hc) promoter. Our findings demonstrate that Sb(R)LD but not Sb(S)LD prevents SAG-induced DC activation by suppressing a PI3K-dependent NF-kappaB pathway and provide the evidence for differential host-pathogen interaction mediated by Sb(R)LD and Sb(S)LD.


Kumar D.,Max-Planck-Institut fur Kohlenforschung | Kumar D.,Indian Institute of Chemical Technology | Thiel W.,Max-Planck-Institut fur 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.


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.


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.


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.


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.


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.


Gayatri G.,Indian Institute of Chemical Technology
Indian Journal of Chemistry - Section A Inorganic, Physical, Theoretical and Analytical Chemistry | Year: 2011

The performance of a range of computational methods in modeling Diels-Alder reactions of acyclic, cyclic and annelated dienes with ethylene has been assessed. The average asynchronicity values, mean, mean absolute deviation and standard deviation values with respect to activation and reaction energies are calculated and the preference for one method over the other is validated. While M05-2X generates less asynchronous transition states, more asynchronous transition states are obtained at M05 level amongst the methods considered. M05/6-311+G(d,p) is found to be adequate in modeling the Diels-Alder reactions involving acyclic systems. M05-2X method in combination with 6-311+G(d,p) basis set is found to be reliable to model the potential energy surface of cyclic systems. For modeling the reactions involving annelated dienes, the MPW1K method along with 6-311+G(d,p) basis set is found to be adequate.


A major limiting factor retarding the clinical success of dendritic cell (DC)-based genetic immunizations (DNA vaccination) is the scarcity of biologically safe and effective carrier systems for targeting the antigen-encoded DNA vaccines to DCs under in vivo settings. Herein, we report on a potent, mannose receptor selective in vivo DC-targeting liposomes of a novel cationic amphiphile with mannose-mimicking shikimoyl head-group. Flow cytometric experiments with cells isolated from draining lymph nodes of mice s.c. immunized with lipoplexes of pGFP plasmid (model DNA vaccine) using anti-CD11c antibody-labeled magnetic beads revealed in vivo DC-targeting properties of the presently described liposomal DNA vaccine carrier. Importantly, s.c. immunizations of mice with electrostatic complex of the in vivo DC-targeting liposome and melanoma antigen-encoded DNA vaccine (p-CMV-MART1) induced long-lasting antimelanoma immune response (100 days post melanoma tumor challenge) with remarkable memory response (more than 6 months after the second tumor challenge). The presently described direct in vivo DC-targeting liposomal DNA vaccine carrier is expected to find future exploitations toward designing effective vaccines for various infectious diseases and cancers.Molecular Therapy (2016); doi:10.1038/mt.2015.215. © 2015 American Society of Gene & Cell Therapy


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.


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.


Manna P.P.,Banaras Hindu University | Hira S.K.,Banaras Hindu University | Das A.A.,Banaras Hindu University | Bandyopadhyay S.,Indian Institute of Chemical Technology | Gupta K.K.,Banaras Hindu University
Cytokine | Year: 2013

IL-15 is a pleotropic cytokine, which plays an important role in natural killer (NK) cell activity, T cell proliferation, and T cell cytotoxic activity. Dendritic cells (DCs) are the major antigen presenting cells in the immune system and presumed to play an important role in immune recognition of allo and xenotransplantation. We showed that IL-15 activated human peripheral blood DC is cytotoxic to human and porcine aortic endothelial cells. Unlike DCs, CD14+ monocytes show no cytotoxicity against the endothelial cells. This cytotoxic potential of IL-15 activated DC against endothelial cells is dose dependent and increases significantly upon treatment of endothelial cells with inflammatory cytokines like TNF-α or IFN-γ. The cytotoxic potential of IL-15 activated DC is associated with apoptosis of endothelial cells, as indicated by the increased Annexin V staining, caspase activation and loss of mitochondrial membrane potential. Further it was observed that DC mediated cytotoxicity against endothelial cell is mediated via granzyme B possibly secreted by the activated DCs. © 2012 Elsevier 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.


Vijai Kumar Reddy T.,Indian Institute of Chemical Technology
European journal of medicinal chemistry | Year: 2013

The first total synthesis of clavaminol-G (1) and 1-aminoundecan-2-ol (2) has been achieved from 10-undecenoic acid using epoxidation, regioselective azidolysis and in situ detosylation and reduction reactions as key steps. The methodology is extended for the synthesis of 1-aminoundecan-2-ol derivatives; namely, methyl 11-amino-10-hydroxyundecanoate (3), 11-amino-10-hydroxyundecanoic acid (4) and 11-aminoundecan-1,10-diol (5). Among these, 1-aminoundecan-2-ol (2) exhibited good antimicrobial activity and promising cytotoxicity towards HeLa, MDA-MB-231, MCF-7 and A549 cell lines with IC50 values of 4.36, 4.02, 3.88 and 6.78 μM, respectively. Compound 3 exhibited good activity against HeLa cells (IC50 = 3.59 μM), while compound 5 showed moderate activity towards HeLa and A549 cell lines. Clavaminol G (1) and compound 4 showed no activity towards all the cell lines. Copyright © 2013 Elsevier Masson SAS. All rights reserved.


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.


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.


Rama Mohan S.,Indian Institute of Chemical Technology
International Journal of Hydrogen Energy | Year: 2015

Energy crisis and decreasing fossil fuel resources have necessitated development of alternative and renewable fuels and the research and development in this area is to play an important role in the coming days. Extensive research is carried on generation of bioenergy from renewable sources across the globe. In that domain, there has been a significant research on generating biohydrogen from wastewater. If the structure and growth of research in this promising R&D area is known, it is useful for researchers and policy makers in their future endeavors. The aim of this paper is to carry out a study on the ongoing research on the generation of biohydrogen from wastewater, by analyzing research publications and patents in the area till-date, to grasp the broader global contours of scientific and technological research going on. © 2015 Hydrogen Energy Publications, LLC.


Athar T.,Indian Institute of Chemical Technology
Advanced Materials Letters | Year: 2015

With the help of facile single source molecular precursor the synthesis of CuAl2O4 nanopowder with well-defined structural framework was carried out via cost-effective soft-chemical approach with two and three coordination state around copper and Aluminum atom respectively. The synthesized nanoparticles were thoroughly characterized by using several physicochemical techniques such as XRD, SEM, TEM, thermal analysis, UV and FT-IR for structural, optical and morphological studies. With the adjustment of reaction parameters allows us for systematic tuning of particle size, shape as well as to control the other functional properties. It can be concluded that self-assembly is an integral part which take place by understanding the metal chemistry during synthetic approach and therefore help to opens a new exciting opportunities for better understanding the reaction conditions, growth and along its mechanistic approach which leads to fabrication of potential nanodevise in near future. © 2015 VBRI press.


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.


Singh A.L.,Banaras Hindu University | Sarma P.N.,Indian Institute of Chemical Technology
Bioremediation Journal | Year: 2010

Lactobacillus acidophilus was used for the removal of As(III) from 50-2000 ppb As(III)-containing water solution. Biosorption of As(III) by L. acidophilus was dependent on concentration (50 to 2000 ppb) and time (0 to 3 h).L. acidophilus(1 mg dry wt/ml) was able to remove 30, 60, 300, 420, 600 ppb As(III) from 50, 100, 500, 1000, and 2000 ppb of As(III)-containing water solution, respectively, within 3 h at pH 7. Moreover, by increasing the biomass of L. acidophilus(2 mg dry wt/ml) removal of As(III) was enhanced 1.66, 1.33, 1.16, 1.42, and 1.33 times, respectively. Fourier transform infrared (FTIR) and electron spectroscopy for chemical analysis (ESCA) spectrum of As(III)-loaded biomass was also investigated. An FTIR sample spectrum of L. acidophilus fresh biomass and As(III)-loaded biomass showed band stretching of fresh and As(III)-loaded biomass for O-H, 3423.43 to 3385.04 cm -1, and for C-O, 1742.82 to 1731.14 cm -1, and signified that -OH and -CO groups were also involved in the removal of As(III) from As(III)-containing water solution. Copyright © 2010 Taylor and Francis Group, LLC.


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.


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.


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.,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.


Patil N.T.,Indian Institute of Chemical Technology
Chemistry - An Asian Journal | Year: 2012

Over the last few years, gold-catalyzed reactions that involved chirality transfer and memory of chirality (MOC) have emerged as a powerful tool in enantioselective synthesis. This technique has allowed for the single-step synthesis of enantioenriched compounds from readily available starting materials. This Focus Review discusses this emerging field with an emphasis on mechanistic aspects and their applications in synthetic organic chemistry. Making memories: Much progress has been made in gold-catalyzed reactions that involve chirality transfer from the substrates to the products. The syntheses, mechanisms, and applications for reactions that involved chirality memory are discussed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Patil N.T.,Indian Institute of Chemical Technology | Nijamudheen A.,Indian Institute of Science | Datta A.,Indian Institute of Science
Journal of Organic Chemistry | Year: 2012

DFT computational studies in the cyclization of aminoalkyne (see structure), which is generated in situ by 2-aminobenzaldehydes and terminal alkynes in the presence of metals and secondary amines, has been investigated. The study revealed that the mode of cyclization (exo vs endo) depends on the protecting group on nitrogen, the oxidation state of copper, and substitution on alkyne. © 2012 American Chemical Society.


Suresh K.I.,Indian Institute of Chemical Technology
ACS Sustainable Chemistry and Engineering | Year: 2013

Global efforts to find renewable feedstocks for the chemical industry are aimed at replacing fossil reserves and a reduction in global warming by employing environmently friendly technologies (green chemistry approaches) for specialty chemical manufacturing. Cardanol, obtained as a byproduct of the cashew processing industry, is an important renewable resource and a unique phenolic compound carrying a 15-carbon side chain in meta position with varying degrees of unsaturation. In this work, the synthesis of new biobased polyols for rigid polyurethane (PU) foams through oxidation of side chain unsaturation is reported using the environmentally benign reagent hydrogen peroxide. Polyols with hydroxyl values in the range of 350-400 mg KOH/g were prepared through epoxidation followed by hydrolysis and characterized for structure using IR,1H-NMR, 13C NMR, and mass spectroscopic techniques. The foaming characteristics were studied, and the polyols were successfully used in making rigid polyurethane foams with good physical and mechanical properties. The foams were characterized for density, compressive strength, morphology, and viscoelastic properties. The properties are compared with that of foams prepared using standard petroleum-based polyols. © 2012 American Chemical Society.


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.


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.


Usha Rani P.,Indian Institute of Chemical Technology
Journal of Biopesticides | Year: 2012

Essential oils isolated from pine (Pinus longifolia L.), Eucalyptus (Eucalyptus obliqua L'Her) and coriander (Coriandrum sativum L.) were screened for contact and fumigant activities against rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae), adzuki bean weevil, Callosobruchus chinensis L. (Coleoptera: Bruchidae) and rice moth Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) in laboratory assays. Responses varied with test material, insect species, and exposure time. In fumigation assay, coriander and eucalyptus oils at 130μg/cm2, caused 100% toxicity to all the species within 24 hrs of treatment, whereas pine oil revealed, 90% mortality at same concentration after 72 hrs of treatment. In contact assay, the test oils were effective against adults of S. oryzae, C. chinensis and C. cephalonica producing about 90% toxicity only after 72 hrs of treatment. Against C. chinensis adults, all test materials revealed potent insecticidal activities than other two insects in both fumigation and contact assays even at lower concentrations. These studies showed the strong insecticidal activity of coriander, eucalyptus and pine oils and its potential role as a fumigant for S. oryzae, C. chinensis and C. cephalonica. From this study we conclude that these essential oils have potential for applications in IPM programs for stored-grain pests because of its high volatility and fumigant activity. ©JBiopest.


Mondal A.,Indian Institute of Chemical Technology
Separation Science and Technology (Philadelphia) | Year: 2015

Ultrasound assisted three phase partitioning (UATPP) has been explored for the extraction of palmitic acid (PA) and elaidic acid (EA) from Cassia sophera Linn. seed powder, and the process were optimized. Ultrasound was applied with TPP to improve the yield with operating frequencies of 25 and 40 kHz and at a power 200 W. The yield of PA and EA was 0.25 ± 0.005% and 0.26 ± 0.006%, respectively, with TPP. The yield was found 0.31 ± 0.002% and 0.32 ± 0.016%, with UATPP at 40 kHz and 180 W power. UATPP was found to be an effective technique. Copyright © Taylor & Francis Group, LLC.


Kumar T.P.,Indian Institute of Chemical Technology
Tetrahedron Asymmetry | Year: 2015

Abstract Organocatalytic enantioselective Michael addition of α,α-disubstituted aldehydes onto nitroolefins using pyrrolidine-oxyimide catalyst was reported. The reaction works effectively under neat conditions with 15 mol % of catalyst and 10 mol % of p-nitrobenzoic acid as an additive at 0 °C; this results in the formation of Michael adducts possessing an all-carbon quaternary center with good yields and enantioselectivities. © 2015 Elsevier Ltd.


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.


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.


Palanisamy A.,Indian Institute of Chemical Technology
Polymer Composites | Year: 2013

The present work deals with the development of polyurethane-clay nanocomposite foams by replacing part of the synthetic polyol with castor oil derivative. Hydroxylated castor oil was converted into diethanol amide by transamidation and the resulting polyol was formulated into water-blown foams. Modified montmorillonite clay was used as nanofiller in different amounts viz. 0.5%, 1.0%, 2.0%, and 5.0% by total weight of the foam formulation. Rheological measurements on the polyol-clay mixtures indicated that up to 1% clay loading there is no significant change in the viscosity with shear rate and beyond 2%, shear thinning occurred. X-ray diffraction studies further substantiated these results. The effect of the modified clay on the density, mechanical properties such as compression strength, compression modulus, and microstructure of the foams were investigated. The filler thus added had a reinforcing effect on the foam as observed in the density and compression strength measurements. Differential scanning calorimetric studies on Tg and dynamic mechanical analyses on the modulus clearly indicated that 1% clay loading and above led to exfoliation and plasticizing effect. Exfoliated nanocomposites in compositions containing 1% clay and more yielded a much higher nucleation rate than intercalated ones leading to reduced cell size as observed by optical and scanning electron microscopy. Thus, castor oil, which is readily available, relatively inexpensive, and environmentally benign nonedible oil, has been successfully used to prepare filled semirigid foams which can find application in insulation and packing. POLYM. COMPOS. 34:1306-1312, 2013. © 2013 Society of Plastics Engineers © 2013 Society of Plastics Engineers.


Mukherjee N.,Chittaranjan National Cancer Institute | Bhattacharya N.,Chittaranjan National Cancer Institute | Alam N.,Chittaranjan National Cancer Institute | Roy A.,Government of West Bengal | And 2 more authors.
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.


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.


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.


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.


Giri A.K.,Indian Institute of Chemical Technology
BMC complementary and alternative medicine | Year: 2014

Darjeeling tea, a most popular variety of black tea, though consumed by the people in different parts of world but its beneficial health effects have not been investigated in details. In this study, the antimutagenic and anticancer effect of Darjeeling tea extract (DTE) has been evaluated. Antimutagenic activity of the DTE was carried out in two different strains of Salmonella typhimurium by AMES test against a known mutagen benzo[a]pyrene (B[a]P) with S9 activation. Moreover, anticlastogenic property of DTE was also measured by micronuclei formation (MN) against B[a]P with S9 activation in human lymphocytes. The anticancer activity of the same was studied on U937 cell line. Here, Human PBMCs were used as the normal cell control to identify selective anticancer activity of the extract against U937 cells. The results showed significant antimutagenic activity on bacterial strains. A significant decrease in MN was also observed in the DTE treated human lymphocyte cultures pretreated with B[a]P when compared with B[a]P treated cultures alone. The study clearly exhibited anticancer activity of the extract on U937 cell line. Further studies also revealed that apoptosis induction is an important mechanism behind the anticancer effect of DTE. Overall, this study indicates that DTE has significant antimutagenic and anticancer activities on bacterial and mammalian cells respectively.


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.


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.


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.


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.


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.


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.


Srivastava R.,Indian Institute of Chemical Technology
Computational and Theoretical Chemistry | Year: 2014

Changes in the ground state and excited state properties of the [Ru(bpy)3]2+ complex induced by functionalization of bpy ligands with N-heterocyclic carbene ligand (imidazolylidene, benzimidazolylidene and 1,2,3-triazolylidene) and substituted methyl wingtip group in protonated and deprotonated forms were studied theoretically using DFT and TDDFT methods. The absorption band is broader and features approximately a 26nm more bathochromic tail than the [Ru(bpy)3]2+. Our calculations show that red shift for 1,2,3-triazolylidene ligand in the protonated series is only due to the affect of the energies of LUMOs which is localized on the substituted ligands. Consistent with previously observed trends in absorption spectra of Ru (II) complexes, a blue shift is observed for the deprotonated series. The effect originates from interplay of positive and negative solvatochromism in 1-3 and 1a-3a complexes respectively. This results in more delocalized character of the electron transition orbitals in the deprotonated complexes. We performed an NTO analysis based on the calculated transition density matrices to analyze the calculated singlet states. The calculated triplet excited state can either be weakly optically allowed 3MLCT or optically forbidden Ru 3d-d transitions. The ability to reduce the HOMO-LUMO gap by the carbene ligand is expected to be beneficial for photovoltaic applications. © 2014 Elsevier B.V.


Kumar A.K.,IICT CCMB Dispensary | Mohan S.V.,Indian Institute of Chemical Technology
Desalination | Year: 2011

Global concern about the persistence of endocrine disrupting chemicals (EDC) in the freshwater environment is more evident due to their possible disruptive effects. Even at nanogram levels these compounds increase the risk of cancer, decrease egg and sperm production, reduce gamete quality and tend complete feminization of the male fish. The present study demonstrated the potential of activated charcoal as adsorbent in removing synthetic estrogen 17α-ethynylestradiol (EE2) from aqueous phase by sorption process employing both agitated batch and column adsorption experiments. Batch sorption studies showed good removal of EE2 and dependent on the concentration loaded. Equilibrium data of EE2-charcoal sorption system showed a reasonably good fit with pseudo first-order kinetic plot. Intra-particle diffusion plot indicated the complex nature of EE2-charcoal sorption system involving both boundary layer and intra-particle diffusions. Experimental data confirmed to linear Langmuir's isotherm model. Highest EE2 sorption capacity of activated charcoal was observed at neutral conditions. Fixed bed column studies were performed with EE2 spiked untreated domestic sewage. Based on the data derived by fixed bed column studies, rapid small-scale column test (RSSCT) methodology was used to design full-scale GAC system. Total EE2 concentration was quantitatively estimated by direct competitive immuno-enzymatic colorimetric method. © 2011 Elsevier 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.


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.


Hassan T.A.,Tuskegee University | Rangari V.K.,Tuskegee University | Rana R.K.,Indian Institute of Chemical Technology | Jeelani S.,Tuskegee University
Ultrasonics Sonochemistry | Year: 2013

A novel combination of mechanochemical and sonochemical techniques was developed to produce high-surface-area, bio-based calcium carbonate (CaCO 3) nanoparticles from eggshells. Size reduction of eggshell achieved via mechanochemical and followed by sonochemical method. First, eggshells were cleaned and ground, then ball milled in wet condition using polypropylene glycol for ten hours to produce fine particles. The ball milled eggshell particles were then irradiated with a high intensity ultrasonic horn (Ti-horn, 20 kHz, and 100 W/cm2) in the presence of N,N-dimethylformamide (DMF); decahydronaphthalene (Decalin); or tetrahydrofuran (THF). The ultrasonic irradiation times varied from 1 to 5 h. Transmission electron microscopic (TEM) studies showed that the resultant particle shapes and sizes were different from each solvent. The sonochemical effect of DMF is more pronounced and the particles were irregular platelets of ∼10 nm. The BET surface area (43.687 m2/g) of these nanoparticles is much higher than that of other nanoparticles derived from eggshells. © 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.


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.


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.


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.


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.


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.


Density functional theory (DFT) and time-dependent density functional theory (TDDFT) are used to analyse theoretically the optoelectronic, photophysical properties and organic light-emitting diode performance of a series of fac-mer blue-emitting Iridium (III) carbene complexes. Swain-Lupton constant is used to discuss the substituents effect. 5d-orbital splitting and d-d∗ transitions are calculated to assess the efficiency of the studied complexes. The reorganisation energies (λ), transfer integrals, mobilities, radiative decay rate (kr), and triplet exciton generation fraction (χT) are also calculated. Due to the higher χT of these complexes, the formation of triplet exciton will be more and it will cause a faster intersystem crossing. Two host materials are proposed and host-guest match (Dexter-Förster energy) is also discussed. We hope that this unified work will surely help to design new blue-emitting phosphorescent materials in future. © 2015 Taylor and Francis.


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.


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.


Sridhar B.,Indian Institute of Chemical Technology
Acta Crystallographica Section C: Structural Chemistry | Year: 2015

Multicomponent crystals or cocrystals play a significant role in crystal engineering, the main objective of which is to understand the role of intermolecular interactions and to utilize such understanding in the design of novel crystal structures. Molecules possessing carboxylic acid and amide functional groups are good candidates for forming cocrystals. β-Resorcylic acid monohydrate, C7H6O4·H2O, (I), crystallizes in the triclinic space group P with one β-resorcylic acid molecule and one water molecule in the asymmetric unit. The cocrystal thymine-β-resorcylic acid-water (1/1/1), C5H6N2O2·C7H6O4·H2O, (II), crystallizes in the orthorhombic space group Pca21, with one molecule each of thymine, β-resorcylic acid and water in the asymmetric unit. All available donor and acceptor atoms in (I) and (II) are utilized for hydrogen bonding. The acid and amide functional groups are well known for the formation of self-complementary acid-acid and amide-amide homosynthons. In (I), an acid-acid homosynthon is observed, while in (II), an amide-acid heterosynthon is present. In (I), the β-resorcylic acid molecule exhibits the expected intramolecular S(6) motif between the hydroxy and carbonyl O atoms, and an intermolecular R 2 2(8) dimer motif between the carboxylic acid groups; only the former motif is observed in (II). The water solvent molecule in (I) propagates the discrete dimers into two-dimensional hydrogen-bonded sheets. In (II), thymine and β-resorcylic acid molecules do not form self-complementary amide-amide and acid-acid homosynthons; instead, a thymine-β-resorcylic acid heterosynthon is observed. With the help of the water molecule, this heterosynthon is aggregated into a three-dimensional hydrogen-bonded network. The absence of thymine base pairing in (II) might be linked to the availability of additional functional groups and the preference of the donor and acceptor hydrogen-bond combinations. © 2015 International Union of Crystallography.


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.


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.


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.


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.


A new series of 3- amino -9- chloro-8- fluoro -4- oxo- (2H)/aryl/heteryl- pyrazolo[ 3',4': 4, 5] pyrimido [ 2,1 -b ] [ 1,3 ] benzothiazole and its derivatives were synthesized . The antimicrobial activity of the synthesized compounds were studied by disc diffusion method using various strains of microbes and compared with standard drug streptomycin. The antifungal activity was also evaluated against four fungal strains and compared with amphotericin -B as standard. The biological activity of the synthesized compounds were found to be good to moderate.


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.


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.


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.


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.


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.


Modugu N.R.,Indian Institute of Chemical Technology | Mehta G.,University of Hyderabad
Tetrahedron Letters | Year: 2015

A new, short, approach toward bioactive antroquinonols has been conceptualized wherein the key carbocyclic core has been readily assembled employing disposable norbornyl scaffold as the regio- and stereo-director and a Wittig olefination based strategy is projected for appending the farnesyl arm. © 2015 Elsevier Ltd. All rights reserved.


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 | 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.


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.


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.


Nair R.V.,CSIR - National Chemical Laboratory | Kheria S.,CSIR - National Chemical Laboratory | Rayavarapu S.,CSIR - National Chemical Laboratory | Kotmale A.S.,CSIR - National Chemical Laboratory | And 5 more authors.
Journal of the American Chemical Society | Year: 2013

Here, we report on a new class of synthetic zipper peptide which assumes its three-dimensional zipper-like structure via a co-operative interplay of hydrogen bonding, aromatic stacking, and backbone chirality. Structural studies carried out in both solid- and solution-state confirmed the zipper-like structural architecture assumed by the synthetic peptide which makes use of unusually remote inter-residual hydrogen-bonding and aromatic stacking interactions to attain its shape. The effect of chirality modulation and the extent of noncovalent forces in the structure stabilization have also been comprehensively explored via single-crystal X-ray diffraction and solution-state NMR studies. The results highlight the utility of noncovalent forces in engineering complex synthetic molecules with intriguing structural architectures. © 2013 American Chemical Society.


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


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.


Patent
Council Of Scientific And Industrial Research and Indian Institute of Chemical Technology | Date: 2010-06-29

The invention relates to nanotubes and processes for making them and intermediates of a drug moiety or its derivative/s as a structural moiety with side chain/s capable of promoting self aggregation. The side chain/s are mono or a multiple of alkyl chain/s that are substituted or unsubstituted capable of creating self aggregating assemblies. A p-amino benzoic acid (PABA) moiety or derivative as a structural moiety of 4-alkylamido-N-pyridin-2yl-benzamide with a lauric or stearic side chain. 4-alkylamido-N-pyridin-2yl-benzamide and 4-Amino-N-pyridine-2 yl-benzamide, N-(Pyridine-2-yl)-4-dodecanamido-benzamide and N-(Pyridin-2-yl)-4-stearamidobenzamide are intermediates useful for in vivo Conjugation of an active ingredient, illustrated by Rhodamine B. With Rhodamine B as an active ingredient, nano-tubes prepared with lauric side chain, which show red fluorescence and is useful for in vivo tracking.


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.


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.


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.


Rani K.Y.,Indian Institute of Chemical Technology
Journal of Process Control | Year: 2012

A novel sensitivity compensating nonlinear control (SCNC) approach is proposed within generic model control (GMC) framework for processes exhibiting input sensitivity. The proposed approach consists of defining a new process, control law and set point such that the determined control action drives the original process to its desired set point. External reset feedback (ERF), used to compensate for input saturation, is extended to higher relative degree systems as extended ERF (EERF), and is incorporated in the context of SCNC approach. The proposed control algorithms are evaluated by application to an open-loop unstable CSTR control problem and a multi-product semi-batch polymerization reactor temperature control problem. The present study illustrates the versatility of the proposed SCGMC schemes compared to the basic GMC schemes in terms of output tracking and smoother input profiles. SCNC can be extended to other nonlinear model based controllers where the control law can be expressed analytically. © 2012 Elsevier Ltd. 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.


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.


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.


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.


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.


Manna P.P.,Banaras Hindu University | Chakrabarti G.,Indian Institute of Chemical Technology | Bandyopadhyay S.,Indian Institute of Chemical Technology
Vaccine | Year: 2010

Antileishmanial role of mouse splenic natural killer (NK) cell was studied in allogeneic condition. In vitro data indicates that NK cells of allogeneic (C57BL/6, H2b) non-leishmania exposed mouse have strong antileishmanial effect against Leishmania donovani infected BALB/c (H2d) macrophages. Physical contact between the effector (NK cell) and the target cells (infected macrophages) is essential in this system since; cell free supernatant generated after coculturing of effector cells with infected target cells fails to elicit any antileishmanial effect. Although NK cells from allogeneic mouse are strongly attached to the infected macrophages but unable to kill it in such interaction. The antileishmanial effect of allogeneic NK cells is mediated by TNF-α and not by IFN-γ. In vivo cellular therapy of established infection with NK cells from non-leishmania exposed allogeneic mouse significantly reduces the total parasite burden in the spleen of infected animal. Crown Copyright © 2009.


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.


Raghwan,Indian Institute of Chemical Technology | Chowdhury R.,Indian Institute of Chemical Technology
Helicobacter | Year: 2014

Background: Helicobacter pylori, a gram negative bacterium, colonizes the stomach in a majority of the world population. The two major virulence factors of H. pylori VacA and CagA, thought to be associated with chronic inflammation and disease, have been extensively studied, but the regulation of the expression of these virulence genes in H. pylori remains poorly understood. Methods: qRT-PCR was performed to quantify gene expression in unadhered and AGS-adhered H. pylori. Δfur mutant was constructed by splicing by overlap extension PCR and allelic exchange. Results: Adherence of H. pylori to the gastric epithelial cell line AGS strongly induces the expression of both cagA and vacA. Induction of cagA and vacA in the AGS cell-adhered H. pylori Δfur mutant strain was consistently lower than in the adhered parent strain. However, expression of the genes was similar between the wild-type and Δfur mutant strains in the unadhered state, suggesting that Fur has a role in the upregulation of cagA and vacA expression, especially in AGS-adhered H. pylori. Consistent with these results, microscopic observations revealed that infection of AGS cells with H. pylori Δfur mutant strain produced much less damage as compared to that produced by the wild-type H. pylori strain. Conclusions: These results suggested that cagA and vacA gene expression is upregulated in H. pylori, especially by host cell contact, and Fur has a role in the upregulation. © 2013 John Wiley & Sons Ltd.


Ramesh P.,Indian Institute of Chemical Technology | Meshram H.M.,Indian Institute of Chemical Technology
Tetrahedron | Year: 2012

A synthetic approach for the total synthesis of salinipyrone A has been developed. Key steps involve the TiCl 4-mediated vinylogous Mukaiyama aldol reaction (VMAR) of chiral ketene silyl N,O-acetal with propionaldyhyde, an aldol condensation, Witting olefination, and a cyclization. The synthesis proceeds in eight steps. © 2012 Elsevier Ltd. All rights reserved.


Ramesh P.,Indian Institute of Chemical Technology | Meshram H.M.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2012

An efficient synthesis of (-)-anamarine is described using d(+)-mannitol and (R)-epichlorohydrin. The synthesis is achieved starting from easily accessible d(+)-mannitol using a selective benzoylation, regioselective epoxide ring opening, a selective acetonide deprotection, tosylation and cross metathesis reaction. © 2012 Elsevier Ltd. All rights reserved.


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.


Sathish Reddy A.,Indian Institute of Chemical Technology | Srihari P.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2012

A concise stereoselective total synthesis of alkaloid (-)-allonorsecurinine is described utilizing classical reactions such as Grignard, Aldol and Horner-Wittig reactions as the key steps. © 2012 Elsevier Ltd. All rights reserved.


Radha Krishna P.,Indian Institute of Chemical Technology | Kadiyala R.R.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2012

A combination of diastereoselective Baylis-Hillman reaction and RCM reaction set is used as the flexible strategy for the ready access to cyclohexenoid and cyclopentenoid skeletons. © 2011 Elsevier Ltd. All rights reserved.


Mehta G.,University of Hyderabad | Samineni R.,University of Hyderabad | Samineni R.,Indian Institute of Chemical Technology | Srihari P.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2012

A concise, enantiodivergent formal synthesis of (+)-paecilomycine A and its antipode, involving a 1,4-chirality transfer protocol and an intramolecular Pauson-Khand reaction as the key steps is outlined. © 2011 Elsevier Ltd. All rights reserved.


Kumar J.N.,Indian Institute of Chemical Technology | Das B.,Indian Institute of Chemical Technology
Synlett | Year: 2014

The first stereoselective total synthesis of the immunosuppressive decalin derivative monascusic acid B has been accomplished from (R)-(+)-pulegone involving Horner-Wadsworth-Emmons and Julia-Kocienski olefination reactions and Lewis acid catalyzed intramolecular Diels-Alder cyclization. © Georg Thieme Verlag Stuttgart New York.


Mishra G.P.,Indian Institute of Chemical Technology | Rao B.V.,Indian Institute of Chemical Technology
Tetrahedron Asymmetry | Year: 2011

An efficient method for the syntheses of cyclopentitols from d-ribose is described using Nozaki-Hiyama-Kishi conditions and ring closing metathesis. In this transformation ω-deoxy-ω-iodo ribofuranoside undergoes reductive elimination in the presence of CrCl2 to give the corresponding olefin-aldehyde, which was trapped by a nucleophile under the same conditions to afford the desired diolefinic species. The ring closing metathesis reaction on the diolefinic species with a Grubbs second generation catalyst produced the required carbocycles. © 2011 Elsevier Ltd. All rights reserved.


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.


Srinu G.,Indian Institute of Chemical Technology | Srihari P.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

A metal-free and catalytic approach for the preparation of allylic azides starting from aryl vinyl carbinols is described herein. © 2013 Elsevier Ltd. All rights reserved.


Reddy C.R.,Indian Institute of Chemical Technology | Latha B.,Indian Institute of Chemical Technology
Tetrahedron Asymmetry | Year: 2011

The use of a β-amino aldehyde derived from l-aspartic acid as a chiral synthon to construct 2,6-disubstituted piperidines is described. The synthesis of (-)-dihydropinidine·HCl, (2S,6R)-isosolenopsin·HCl and (+)-monomorine has been achieved from this chiral synthon using a Wittig reaction followed by hydrogenation (reductive cyclization) as the key steps. © 2011 Elsevier Ltd. All rights reserved.


Nageswara Rao N.,Indian Institute of Chemical Technology | Meshram H.M.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

A highly efficient method is described for the sp3 C-H bond functionalization of methyl aza-arenes in the presence of water under microwave irradiation and subsequent addition to aromatic aldehydes. This transformation represents an efficient way to synthesize 2-alkyl aza-arene derivatives from simple starting materials. © 2013 Elsevier Ltd. All rights reserved.


Purushotham Reddy S.,Indian Institute of Chemical Technology | Venkateswarlu Y.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

The first stereoselective synthesis of the cytotoxic (-)-kunstleramide (1) has been reported from simple and commercially available starting material 3,4-dimethoxyphenylpropanol. The key steps involved are the MacMillan α-hydroxylation, Horner-Wadsworth-Emmons (HWE) olefination, and amide-Wittig olefination. © 2013 Elsevier Ltd. All rights reserved.


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.


Chandrasekhar S.,Indian Institute of Chemical Technology | Sreelakshmi L.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2012

The formal total synthesis of the important toxin fumonisin B 1 is achieved from simple raw materials in a convergent manner. The key functionalities are derived from MacMillan α-hydroxylation, sharpless asymmetric dihydroxylation and ring-closing metathesis. © 2012 Elsevier Ltd. All rights reserved.


Radha Krishna P.,Indian Institute of Chemical Technology | Prabhakar S.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

Herein we report the first stereoselective total synthesis of phomonol via Sharpless asymmetric dihydroxylation and 6-exo-trig oxa-Michael addition as the key steps. © 2013 Elsevier Ltd. All rights reserved.


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.


Kannaiah Goud R.,Indian Institute of Chemical Technology | Venkata Mohan S.,Indian Institute of Chemical Technology
International Journal of Hydrogen Energy | Year: 2011

Functional role of pre-fermentation of food waste (PFW) was studied to enhance the performance of single chambered microbial fuel cell (MFC) (mediatorless; non-catalyzed graphite electrodes; open-air cathode). Significant improvement in power output was noticed after pre-treatment (391 mV; 530 mA/m2) compared to unfermented waste (275 mV; 361 mA/m2). MFC performance was found to depend on applied organic load and nature of substrate in terms of power generation and substrate degradation. The pre-fermentation of waste facilitated lowering of activation losses and in turn increased the bio-electrochemical activity of biocatalyst, leading to an effective MFC performance. Fuel cell behavior with respect to polarization, anode potential and bio-electrochemical behavior also supported the performance of MFC with PFW. PFW operation showed higher catalytic current in voltammograms with fine catalytic peaks supporting the positive role of pre-fermentation in discharging electrons effectively. VFA and pH profiles also correlated well with power generation and substrate degradation pattern. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


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.


Kumaraswamy G.,Indian Institute of Chemical Technology | Pitchaiah A.,Indian Institute of Chemical Technology
Helvetica Chimica Acta | Year: 2011

The syntheses of enantiomer-enriched orthogonally protected different (2S)-2,3-diaminopropanoates and unnatural furyl-substituted (tert-butoxy) carbonyl (Boc) as well as (benzyloxy)carbonyl (Cbz) protected amino acid esters are accomplished by means of an enantioselective aza-Henry reaction. A key feature of this protocol is organocatalysis as a genesis of chirality to ensure high enantioselectivity. Copyright © 2011 Verlag Helvetica Chimica Acta AG, Zürich, Switzerland.


Nagaraju M.,Indian Institute of Chemical Technology | Narahari Sastry G.,Indian Institute of Chemical Technology
Journal of Molecular Modeling | Year: 2011

The effect of alkyl substitution (CH3, C2H 5, n-C3H7, i-C3H7, and t-C4H9) on the hydrogen bond strengths (H-bond) of substituted amide-alcohol complexes has been systematically explored. B3LYP/aug-cc-pVDZ method was applied to a total of 215 alkyl substituted amide-alcohol complexes to delineate the effect of substitution on the H-bond strength; formamide-water complex is taken as reference point. Complexes are classified into five types depending on the hydrogen donor, acceptor and the site of alkyl substitution (Type-IA, Type-IIA, Type-IB, Type-IIB and Type-III). The strength of H-bond was correlated with geometrical parameters such as proton-acceptor (H-Y) distance, the length of proton donating bond (X-H). In all the complexes N-H and O-H stretching frequencies are red-shifted. The effect of alkyl substitution on N-H and O-H stretching frequencies were analyzed. Topological parameters like electron density at H-Y and X-H bond critical points as derived from atom in molecules (AIM) theory was also evaluated. When C=O group is participating in H-bond, the strength of H-bond decreases with increasing size of alcohols except for methanol (Type-IA, Type-III and Type-IB complexes). But it increases with increasing size of alkyl groups on amide and decreases with bulky groups. In the case of N-H group as H-bond donor, the strength of H-bond increases with increasing size of alcohols (Type-IIA and Type-IIB complexes) whereas decreases with increasing size of alkyl groups on amide. Type-IA, IIA, IB and IIB complexes exhibit good correlations among IE, H-bond distance and electron density at bcp. In Type-III complexes, average H-bond distance and sum of electron densities shows better correlation with IEs than the corresponding individuals. The correlation of IE less with electron density at RCP compared to sum of electron densities. © 2010 Springer-Verlag.


Narsaiah A.V.,Indian Institute of Chemical Technology | Ghogare R.S.,Indian Institute of Chemical Technology
Synthesis | Year: 2011

An efficient and straightforward stereoselective synthesis of (6S)-6-[(2R)-2-hydroxy-6-phenylhexyl]-5,6-dihydro-2H-pyran-2-one is described. The chiral centers were generated by Sharpless asymmetric epoxidation followed by regioselective epoxide ring opening with Red-Al to afford 1,3-diols, exclusively. All the reactions were very clean and the products were obtained in very good yields. © Georg Thieme Verlag Stuttgart · New York.


Umadevi D.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology
Journal of Physical Chemistry C | Year: 2011

Understanding the nature of nonbonded interactions on the graphene surface is a problem of outstanding interest. Highly reliable M05-2X/6-311++G** //M05-2X/6-31G* DFT calculations were performed to understand the interaction of small molecules and ionic species with graphenes. Various linear and branched polycyclic aromatic hydrocarbons (PAHs) were taken as models of the graphene surface, and their interaction with small molecules (CO2 and H2O), metal atoms (Li and Mg), and metal ions (Li+ and Mg2+) has been studied. The effect of ring size is found to be profound on the interaction energy values and shows an interesting contrast with various species. Our results indicate that the metal atoms and ions are chemisorbed, while CO2 and H2O are physisorbed on the PAH surface. H2O displays a stronger affinity for complexation compared to CO2. The binding strength of the molecules has been correlated with the nucleus independent chemical shift (NICS), a local aromaticity index, highest occupied molecular orbital (HOMO) energy, and polarizability of PAHs. © 2011 American Chemical Society.


Vidadala S.R.,CSIR - National Chemical Laboratory | Gayatri G.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology | Hotha S.,Indian Institute of Science
Chemical Communications | Year: 2011

Transfuranosylations are not well studied though many similar studies exist for transpyranosylation; herein, we report that propargyl/methyl d-ribf- and d-lyxf- give only 1,2-trans glycosides whereas d-araf- and d-xylf- result in a mixture of 1,2-trans and 1,2-cis glycosides; observed facts are rationalised by computational studies. © 2011 The Royal Society of Chemistry.


Putta C.B.,Indian Institute of Chemical Technology | Ghosh S.,Indian Institute of Chemical Technology
Advanced Synthesis and Catalysis | Year: 2011

We report the use of palladium nanoparticles stabilized on amphiphilic glucose-derived carbon spheres as heterogeneous catalysts for Suzuki-Miyaura reactions. Reactions of aryl halides with various boronic acids in the presence of different bases and solvents including organic polar, non-polar and water as sole solvent without the aid of phase-transfer catalysts, under phosphine-free and aerobic conditions have been studied. Especially, deactivated aryl bromides and activated aryl chlorides afforded good isolated yields in pure water. The catalyst was reused for up to four cycles without any marked loss in the activity. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Ghosh S.,Indian Institute of Chemical Technology | Pradhan T.K.,Indian Institute of Chemical Technology
Journal of Organic Chemistry | Year: 2010

"Chemical Equation Presented" Stereoselective total syntheses of natural (+)-varitriol (1), (-)-varitriol (2), 5'-epi-(+)-varitriol (3), and 4'-epi-(-)varitriol (4) have been accomplished with use of D-mannitol as a chiral pool material. The Heck reaction was used to assemble the olefinic sugar moiety and the aromatic triflate moiety. © 2010 American Chemical Society.


Singh S.P.,Indian Institute of Chemical Technology | Nagarjuna P.,Indian Institute of Chemical Technology
Dalton Transactions | Year: 2014

Organometal halide perovskites offer dual potential properties as a light harvester and at the same time as a hole conductor in inorganic-organic hybrid heterojunction solar cells. The sequential deposition route provides a power conversion efficiency of 15% under standard AM1.5G test conditions. In this perspective, we will briefly summarize the development of perovskite-sensitized solar cells from their first report up to the present. This journal is © the Partner Organisations 2014.


Sathish Reddy A.,Indian Institute of Chemical Technology | Srihari P.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

The first total synthesis of the natural product (-)-petrosiol D has been achieved in a linear fashion. Sharpless asymmetric epoxidation, base induced elimination reaction for the formation of chiral propargyl alcohol and Cadiot-Chodkiewicz coupling reaction are the key steps utilized for the synthesis. © 2013 Elsevier Ltd. All rights reserved.


Rajender A.,Indian Institute of Chemical Technology | Rao B.V.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2013

A highly stereoselective approach to aminocyclohexenetriols conduramine C-1 1 and conduramine D-1 2 has been described. Conduramines are structural units of some biologically active natural products such as (+)-lycoricidine and (+)-narciclasine. The strategy developed by us for their synthesis is general in nature to make related skeletons and also the molecules containing conduramine structural unit. The key reactions are Grignard addition on glycosylamine, ring closing metathesis (RCM), and Mitsunobu inversion. © 2013 Elsevier Ltd. All rights reserved.


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.


Rajesh S.,Biomedical Research Laboratory | Kanugula A.K.,Indian Institute of Chemical Technology | Bhargava K.,Defence Institute of Physiology and Allied science DIPAS | Ilavazhagan G.,Defence Institute of Physiology and Allied science DIPAS | And 2 more authors.
Biosensors and Bioelectronics | Year: 2010

A novel highly sensitive biosensor for the direct and simultaneous determination of superoxide anion radical (O 2 -) and nitrite (NO 2 -) was developed by incorporation of carbon nanotube (CNT) solubilized in nafion in polypyrrole (PPy) matrix on Pt electrode followed by immobilization of Cu,ZnSOD (SOD1) on it. The CNT/PPy nanocomposite electrode enhanced the immobilization of SOD1 and promoted the electron transfer of SOD1 minimizing its fouling effect. The surface morphological images of PPy and CNT-PPy nanocomposite on Pt electrode were obtained by scanning electron microscopy exhibiting highly microporous structures. The electrochemical behavior of the biosensor investigated by cyclic voltammetry revealed that the SOD1 immobilized electrode showed characteristic of SOD1 quasi-reversible redox peaks with a formal potential of +0.065V vs. Ag/AgCl. The biosensor exhibited a linear response over the concentration range from 0.1 to 750μM, with a detection limit of 0.1±0.03μM for O 2 - and a corresponding linear range of 0.5-2000μM, with a detection limit of 0.5±0.025μM for NO 2 -. In addition, the biosensor exhibited high sensitivity, good reproducibility and retained stability over 30 days. This modified electrode was quite effective not only in detecting O 2 - and NO 2 - independently but also determining the concentration of O 2 - and NO 2 - simultaneously in vitro and from cancer cells. © 2010 Elsevier B.V.


Reddy C.R.,Indian Institute of Chemical Technology | Das B.,Indian Institute of Chemical Technology
Tetrahedron Letters | Year: 2014

The (Z)-isomer of a phytotoxic nonenolide, (6S,7R,9R)-6,7-dihydroxy-9- propylnon-4-eno-9-lactone isolated from Phomopsis sp. HCCB03520 and its C-6 epimer have been synthesized through a common route starting from butyraldehyde. The synthesis involves enantioselective Maruoka allylation, Sharpless asymmetric epoxidation and intramolecular ring closing metathesis as the important steps. © 2013 Elsevier Ltd. All rights reserved.


Rani P.U.,Indian Institute of Chemical Technology | Devanand P.,Indian Institute of Chemical Technology
Journal of Pest Science | Year: 2013

Feeding deterrent and growth inhibitory effects of caffeic acid methyl ester (CME) isolated from the fruit extract of eggplant, Solanum melongena L. along with two known phenolic acids, caffeic acid (CA) and chlorogenic acid (CG) and azadirachtin (taken as active control), were evaluated against Spodoptera litura Fab. and Achaea janata L. (Lep., Noctuidae). The structure of CME was determined on the basis of extensive spectroscopic (UV, FTIR, 1H, and 13C NMR) data analysis. CME has exhibited strong feeding deterrent activity against S. litura and A. janata larvae with ED50 values of 52.02 and 41.02 μg/cm2 leaf area, respectively. CA and CG were relatively less effective compounds when compared with CME. The results also revealed that the isolated compound CME caused marked larval growth inhibition in S. litura and A. janata larvae after 7 days of feeding on a treated diet. The effect on growth of larvae was concomitant with the reduced feeding and digestibility of ingested food. So the activities of digestive proteases within the midgut of larvae were examined using specific substrates to understand the digestive physiology in the larval guts. The bulk of the activity was associated with serine proteases comprising trypsin-, chymotrypsin-, and elastase-like enzymes, which decreased in diets containing CME, whereas, interestingly increased with CG. From the results, we conclude that CME isolated from S. melongena fruit extract shows feeding deterrent and larval development inhibitory activities that may prove useful in the management of S. litura and A. janata larvae. © 2013 Springer-Verlag Berlin Heidelberg.


Kumbhare R.M.,Indian Institute of Chemical Technology | Nagragu C.,Indian Institute of Chemical Technology
Letters in Drug Design and Discovery | Year: 2011

Efficient synthesis of 4H-pyrimido[2,1-b]benzothiazoles by novel one-pot three-component reaction of an aldehyde, β-ketoester and 2-aminobenzothiazole using sulphamic acid as a catalyst is described. All synthesized compounds were evaluated for in vitro antibacterial activity using Gram-positive bacteria and Gram-negative bacteria (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa , Bacillus subtilis, Proteus Valgaris). In vitro antifungal activity was also determined against the five fungal species (Aspergillus flavus, Candida albicans Aspergillus fumigatus, Penicillium mareneffei, Chrysosporium tropicum). Structure of the synthesized compounds was established by elemental analysis and spectral data. © 2011 Bentham Science Publishers Ltd.


Umadevi D.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology
Journal of Physical Chemistry Letters | Year: 2011

Quantum chemical calculations reveal that the binding energy of the carbon nanotube (CNT) and DNA/RNA nucleobase complexes is controlled by the curvature of the carbon nanotube. Graphene not only has higher affinity but also appears to be best suited to differentiate various nucleobases compared with carbon nanotubes. The dispersion-corrected DFT and M06-2X functionals are in excellent agreement with the experimental observations. Interestingly, nucleus-independent chemical shift (NICS) calculations indicate substantial enhancement of aromaticity for all nucleobases upon binding to graphene and CNT. © 2011 American Chemical Society.


Chowdhury S.,Indian Institute of Science | Mukherjee T.,Indian Institute of Chemical Technology | Sengupta S.,Indian Institute of Science | Chowdhury S.R.,Indian Institute of Science | And 2 more authors.
Molecular Pharmacology | Year: 2011

Toward developing antileishmanial agents with mode of action targeted to DNA topoisomerases of Leishmania donovani, we have synthesized a large number of derivatives of betulin. The compound, a natural triterpene isolated from the cork layer of Betula spp. plants exhibits several pharmacological properties. Three compounds (disuccinyl betulin, diglutaryl dihydrobetulin, and disuccinyl dihydrobetulin) inhibit growth of the parasite as well as relaxation activity of the enzyme type IB topoisomerase [Leishmania donovani topoisomerase I (LdTOP1LS)] of the parasite. Mechanistic studies suggest that these compounds interact with the enzyme in a reversible manner. The stoichiometry of these compounds binding to LdTOP1LS is 1:1 (mole/mole) with a dissociation constant on the order of ∼10 -6 M. Unlike CPT, these compounds do not stabilize the cleavage complex; rather, they abrogate the covalent complex formation. In processive mode of relaxation assay condition, these compounds slow down the strand rotation event, which ultimately affects the relaxation of supercoiled DNA. It is noteworthy that these compounds reduce the intracellular parasite burden in macrophages infected with wild-type L. donovani as well as with sodium antimony gluconate resistant parasite (GE1). Taken together, our data suggest that these betulin derivatives can be exploited as potential drug candidates against threatening drug resistant leishmaniasis. Copyright © 2011 The American Society for Pharmacology and Experimental Therapeutics.


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.


Chakraborty S.,Indian Institute of Chemical Technology | Dana S.K.,Indian Institute of Chemical Technology
Chaos | Year: 2010

We report experimental observations of Shil'nikov-type homoclinic chaos and mixed-mode oscillations in asymmetry-induced Chua's oscillator. The asymmetry plays a crucial role in the related homoclinic bifurcation. The asymmetry is introduced in the Chua circuit by forcing a dc voltage. Then by tuning a control parameter, we observed transition from large amplitude limit cycle to homoclinic chaos via a sequence of mixed-mode oscillations interspersed by chaotic states. We provide experimental evidences that the asymmetry effect can also be induced in the oscillatory Chua circuit when it is coupled with another one in a rest state. The coupling strength then controls the strength of asymmetry and thereby reproduces all the features of Shil'nikov chaos. © 2010 American Institute of Physics.


Mishra A.,Indian Institute of Chemical Technology | Deb I.,Indian Institute of Chemical Technology
Advanced Synthesis and Catalysis | Year: 2016

Imino-/enaminophosphonates derived from amines and diethyl phenacyl phosphonates undergo oxidative cyclization via C-H bond activation catalyzed by palladium chloride to provide a convenient route for the synthesis of substituted indol-3-yl and pyrrol-3-yl phosphonates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Velvizhi G.,Indian Institute of Chemical Technology | Venkata Mohan S.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2011

Biocatalyst behavior was comparatively evaluated under diverse microenvironments viz., self-induced electrogenic (bioelectrochemical treatment, BET) and anaerobic treatment (AnT) microenvironments, with real-field pharmaceutical wastewater. Relatively higher treatment efficiency was observed with BET (COD removal, 78.70%) over AnT (32%) along with the power output. Voltammetric profiles of AnT showed persistent reduction behavior, while BET depicted simultaneous redox behavior. BET operation documented significantly higher bio-electrocatalytic activity (k app, 245.22s -1) than AnT (k app, 7.35s -1). The electron accepting conditions due to the presence of electrode in the BET might contributed to higher electrogenesis leading to enhanced substrate degradation along with the removal of multiple pollutants accounting for the effective reduction of toxicity levels of wastewater. Even at higher organic loads, BET operation showed good treatment efficiency without process inhibition. Introduction of electrode-membrane assembly in anaerobic microenvironment showed significant change in the electrocatalytic behavior of biocatalyst resulting in enhanced treatment of complex wastewater. © 2011 Elsevier Ltd.


Panigrahi S.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology
RSC Advances | Year: 2014

Materials which are extensively and effectively reduced by lithium atoms are of outstanding importance in the lithium battery industry and carbonaceous materials show great promise in this area. Benzene (B), naphthalene (N), anthracene (A) and tetracene (T) are considered as prototypical carbonaceous materials, which mimic sp2 allotropical forms of carbon such as graphene, graphite, carbon nanotubes (CNT) and fullerenes. We have studied lithium adsorption in these carbonaceous materials and analyzed the reduction capability of lithium by different approaches. We observed that the binding energy of these polycyclic aromatic hydrocarbon (PAH)-lithium complexes highly depends on the positioning of the lithium atoms and the size of the PAH. The sequential binding energy data show that the adsorption of the second Li atom is more facile in nature as indicated by its higher binding strengths. The NBO charge analysis also reflects that neutral lithium acquires fractional positive charges which vary from 0.4 a.u. to 2.81 a.u upon interaction with the PAH, which is a clear indication of the ability of the lithium atoms to reduce the PAH molecules. A good correlation has been obtained between the extent of charge transfer, binding and deformation energies. The current study provides the first systematic and exhaustive analysis of the sequential addition of Li atoms to carbonaceous materials and computationally estimates the reduction abilities of this class of materials. This journal is © the Partner Organisations 2014.


Singh A.,Indian Institute of Chemical Technology | Mandal D.,Indian Institute of Chemical Technology
International Journal for Parasitology | Year: 2011

The flagellated form of pathogenic parasitic protozoa Leishmania, resides in the alimentary tract of its sandfly vector, where sucrose serves as a major nutrient source. In this study we report the presence of a sucrose transport system in Leishmania donovani promastigotes. The kinetics of sucrose uptake in promastigotes are biphasic in nature with both high affinity K m (K m of ~75μM) and low affinity K m (K m~1.38mM) components. By contrast the virulent amastigotes take up sucrose via a low affinity process with a K m of 2.5mM. The transport of sucrose into promastigotes leads to rapid intracellular acidification, as indicated by changes in the fluorescence of the pH indicator 2′,7′-bis-(2-carboxyethyl)-5-(6) Carboxyfluorescein (BCECF). In experiments with right side-out plasma membrane vesicles derived from L. donovani promastigotes, an artificial pH gradient was able to drive the active accumulation of sucrose. These data are consistent with the operation of a H +-sucrose symporter. The symporter was shown to be independent of Na + and to be insensitive to cytochalasin B, to the flavonoid phloretin and to the Na +/K + ATPase inhibitor ouabain. However, the protonophore carbonylcyanide P- (trifluromethoxy) phenylhydrazone (FCCP) and a number of thiol reagents caused significant inhibition of sucrose uptake. Evidence was also obtained for the presence of a stable intracellular pool of the sucrose splitting enzyme, sucrase, in promastigote stage parasites. The results are consistent with the hypothesis that L. donovani promastigotes take up sucrose via a novel H +-sucrose symport system and that, on entering the cell, the sucrose is hydrolysed to its component monosaccharides by an intracellular sucrase, thereby providing an energy source for the parasites. © 2011 Australian Society for Parasitology Inc.


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.


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.


Sharma G.V.M.,Indian Institute of Chemical Technology | Reddy P.S.,Indian Institute of Chemical Technology
European Journal of Organic Chemistry | Year: 2012

The total synthesis of macrosphelide M is described. The key steps include the preparation of the acid and alcohol fragments from diacetone glucose and (S)-malic acid, respectively, followed by Yamaguchi esterification and macrocyclization of the tris-olefin by ring-closing metathesis. Finally, one-pot deprotection of the PMB and TBS groups with TiCl 4 results in the target. The C-3/C-4 stereocenters of diacetone glucose are used for the introduction of four stereocenters, whereas the fifth stereocenter is realized from (S)-malic acid. The total synthesis of macrosphelide M was achieved from diacetone glucose and (S)-malic acid. The key steps include Yamaguchi esterification and macrocyclization of the tris-olefin by the second-generation Grubbs catalyst. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


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.


Chandrasekhar S.,Indian Institute of Chemical Technology | Sudhakar A.,Indian Institute of Chemical Technology
Organic Letters | Year: 2010

(Figure presented) The divergent and enantioselective total synthesis of the powerful antifungal marine natural product bengazole A has been achieved. © 2010 American Chemical Society.


Kannaiah Goud R.,Indian Institute of Chemical Technology | Venkata Mohan S.,Indian Institute of Chemical Technology
International Journal of Hydrogen Energy | Year: 2012

Detailed experiments were designed to evaluate the function of load-shock treatment strategy (50 g COD/l; 3 days) for selective enrichment of acidogenic hydrogen (H 2) producing consortia in comparison with untreated anaerobic consortia. Experiments performed in suspended-batch mode bioreactors for 520 days illustrated the relative efficiency of load-shock treated consortia in enhancing H 2 production (16.64 mol/kg COD R) compared to untreated-parent consortia (3.31 mol/kg COD R). On the contrary, substrate degradation was higher with control operation (ξ COD, 62.86%; substrate degradation rate (SDR), 1.10 kg COD R/m 3-day) compared to load-shock culture (52.33%; 0.78 kg COD R/m 3-day). Fatty acid composition documented a shift in the metabolic pathway towards acetate formation after applying load-shock, which manifests higher H 2 production. Microbial profiling documented a significant alteration in species composition of microbial communities after repeated load-shock applications specific to enrichment of Firmicutes which are favourable for H 2 production. Dehydrogenase activity was stabilized with each re-treatment, signifying the adaptation inclination of the biocatalyst towards increased proton shuttling between metabolic intermediates, leading to higher H 2 production. Voltammograms of load-shock treated cultures showed a marked shift in oxidation and reduction catalytic currents towards more positive and negative values respectively with increasing scan rate evidencing simultaneous redox-conversion reactions, facilitating proton gradient in the cell towards increased H 2 production. Load-shock treatment facilitates direct cultivation of inoculums at higher substrate load without any chemical pretreatment. This study documented the feasibility of controlling microbial metabolic function by application of load-shock treatment either for preparing inoculum for startup of the reactor or to the reactor resident microflora (in situ) during operation whenever required to regain the process performance. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Kumar T.P.,Indian Institute of Chemical Technology | Haribabu K.,Indian Institute of Chemical Technology
Tetrahedron Asymmetry | Year: 2014

An efficient protocol for the asymmetric catalytic Michael additions of α,α-disubstituted aldehydes to nitroolefins with a pyrrolidine-pyrazole is described. The desired products γ-nitrocarbonyl compounds possessing an all-carbon quaternary center, were obtained in good yields and with high levels of enantioselectivities under solvent-free reaction conditions, employing benzoic acid as an additive. © 2014 Elsevier Ltd. All rights reserved.


Pal C.,Indian Institute of Chemical Technology | Bandyopadhyay U.,Indian Institute of Chemical Technology
Antioxidants and Redox Signaling | Year: 2012

Significance: Parasitic diseases affect hundreds of millions of people worldwide and represent major health problems. Treatment is becoming extremely difficult due to the emergence of drug resistance, the absence of effective vaccines, and the spread of insecticide-resistant vectors. Thus, identification of affordable and readily available drugs against resistant parasites is of global demand. Recent Advances: Susceptibility of many parasites to oxidative stress is a well-known phenomenon. Therefore, generation of reactive oxygen species (ROS) or inhibition of endogenous antioxidant enzymes would be a novel therapeutic approach to develop antiparasitic drugs. This article highlights the unique metabolic pathways along with redox enzymes of unicellular (Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei, Leishmania donovani, Entamoeba histolytica, and Trichomonas vaginalis) and multicellular parasites (Schistosoma mansoni), which could be utilized to promote ROS-mediated toxicity. Critical Issues: Enzymes involved in various vital redox reactions could be potential targets for drug development. Future Directions: The identification of redox-active antiparasitic drugs along with their mode of action will help researchers around the world in designing novel drugs in the future. © Copyright 2012, Mary Ann Liebert, Inc.


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.


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.


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.


Comprehensive experiments were designed to evaluate the function of acid-shock (pH 3; orthophosphoric acid; 24 h) and alkaline-shock (pH 11; NaOH; 24 h) pretreatment methods for the selective enrichment of an acidogenic culture to enhance H 2 production efficiency of mixed anaerobic consortia. Long term (520 days) operation in suspended-batch mode bioreactors illustrated the relative efficiency and feasibility of redox pretreated cultures against an untreated parent culture in enhancing H 2 production. Relatively higher H 2 production was observed with an acid pretreated mixed culture (15.78 mol kg -1 COD R) over alkaline pretreated (9.8 mol kg -1 COD R) and untreated mixed cultures (3.31 mol kg -1 COD R). On the contrary, substrate degradation was higher with untreated culture (ξ COD, 62.86%; substrate degradation rate (SDR), 1.10 kg COD R/m 3-day) and alkaline-shock pretreated mixed culture (ξ COD, 59.93%; SDR, 1.22 kg COD R/m 3-day) compared to the acid-shock culture (ξ COD, 53.4%; SDR, 0.705 kg COD R/m 3-day). Synergetics of microbial inventory, dehydrogenase activity and bio-electro kinetics in association with H 2 production and substrate degradation were also evaluated in detail throughout the operation. Acid pretreatment of the parent culture has resulted in a shift in the fermentation pathway towards acetic acid production, while alkaline pretreatment showed a mixed type fermentation (acetic, butyric, propnoic acids) similar to an untreated parent mixed culture. Dehydrogenase activity of the biocatalyst showed a significant improvement after applying acid pretreatment indicating the increased redox inter-conversion reactions leading to the higher proton gradient in the cell that resulted in higher H 2 production. The redox catalytic currents observed from the cyclic voltammograms (CV) and the output from the Tafel analysis also strongly supported the increased biocatalyst performance after pretreatment, especially at acid-shock. The shift in oxidative and reductive Tafel slopes towards a lower value after applying acid-shock treatment supports the redox inter-conversion reactions required for proton conservation. Microbial profiling revealed that the pretreatment method in the long term operation substantially affected the species composition of microbial communities. Dominance of Clostridia and Bacilli classes were observed in the pretreated culture and indicates their positive role in the H 2 production process. This study shows the feasibility of controlling microbial metabolic functions by repeated application of the pretreatment to the reactor native microflora (in situ) during operation whenever required to regain or modify the process performances. This journal is © 2012 The Royal Society of Chemistry.


Rani P.U.,Indian Institute of Chemical Technology | Ravibabu M.V.,Indian Institute of Chemical Technology
Allelopathy Journal | Year: 2011

Among the chemical defensive strategies developed by the plant, leaf phenolics generated due to insect herbivory play a major role in controlling the herbivore damage. This study deals with the quantitative and qualitative changes in castor (Ricinus communis L) plant leaf phenolics due to the feeding of its major pests, the castor semilooper [Achaea janata (L.)], tobacco caterpillar [Spodoptera litura (Fabricus)] and the capsule borer [Dichocrosis punctiferalis (Guenee)]. The foliar phenolics extracted from the pest damaged leaves were compared between the pests having different modes of feeding. These experiments revealed the presence of elevated levels of phenolic acid in insect infested plants than uninfested plants. Seven individual phenolic acids were monitored by high performance liquid chromatography (HPLC) in pest damaged and normal healthy castor plant leaves and an increase in vanillic, coumaric, ferulic and syringic acids was noted in the insect infested plants. The impact of increased phenolics on pest feeding behaviour and the growth were analysed through antifeedant assays. A significant difference in the modification of phenolic acids between specialist and generalist leaf feeders was found.


Badrinarayan P.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology
Current Pharmaceutical Design | Year: 2013

Kinases are one of the most popular classes of drug targets as they are involved in signal transduction pathways, which are wired through a phosphotransfer cascade and elicit a number of important and essential physiological responses. Kinase specificity has emerged as one of the major issues to be addressed in drug discovery approaches. In most kinases the active site is the ATP binding site and finding suitable hits which maximize the affinity of binding has been traditionally important to obtain the type I inhibitors. While type I inhibitors have effective binding affinity more often than not they encounter side-effects usually associated with specificity. Therefore in recent times it has become indispensable to optimize specificity for developing effective kinase inhibitors. The review presents an overview of kinase drug discovery and the different strategies used to date for the design of kinase leads accounting for their success and failure. A number of strategies exploiting different aspects of kinases like allosteric site, size of the gatekeeper residue, DFG-loop, chemotype selectivity, non-covalent interactions, salt-bridge, solvation, etc. have been explored to circumvent the specificity problem in kinases. The probable hot-spots in kinases having a propensity to bring in specificity have been delineated with special emphasis on the design of type II inhibitors with increased specificity from existing type I using fragment tailoring approach. In this review we illustrate the current strategies by taking p38 MAP kinase as a model and expect that such strategies are general and can be extended to the other members of the kinase family. © 2013 Bentham Science Publishers.


Reddy C.R.,Indian Institute of Chemical Technology | Rao N.N.,Indian Institute of Chemical Technology
RSC Advances | Year: 2012

The formal total synthesis of (-)-exiguolide through the chiral-pool approach is described. The key reactions involved for formation of the macrocyclic core from two subunits are Julia-Kocienski olefination and Yamaguchi macrolactonization. The major methylene bis-tetrahydropyran fragment was achieved in a convergent manner from l-glutamic acid and l-aspartic acid involving the oxa-Michael reaction and an aldol-driven reductive etherification as key steps for the formation of a tetrahydropyran ring. The other sulfone subunit was prepared via an Evans aldol reaction. This journal is © 2012 The Royal Society of Chemistry.


Srikanth S.,Indian Institute of Chemical Technology | Mohan S.V.,Indian Institute of Chemical Technology
RSC Advances | Year: 2012

The functional role of divalent cations viz., iron (Fe 2+), magnesium (Mg 2+), nickel (Ni 2+), zinc (Zn 2+) and manganese (Mn 2+) in regulating the biohydrogen (H 2) production potential of a biocatalyst was evaluated under varying concentrations. The optimum conditions were evaluated in detail and compared with the principle conditions for enhanced conversion efficiency. Higher concentration of Fe 2+ showed an enhanced H 2 production efficiency of the biocatalyst (61.94 mmol) due to its role as a component of hydrogenase and ferredoxin. On the contrary, a higher concentration of Mg +2 showed a higher substrate utilization capability (76.46%) of the biocatalyst. The optimum metal concentration showed a higher H 2 yield (18.23 mol kg -1 COD R; 3.5 mol mol -1 glucose) over principle operation conditions (14.76 mol kg -1 COD R; 2.84 mol mol -1 glucose). Higher concentrations of acetate (78 ± 6%) as the metabolic intermediate over butyrate (12 ± 2%) supported the observed higher H 2 yields. Higher reductive catalytic current over oxidative current along with the enhanced dehydrogenase activity supported the higher H 2 production efficiency. Shift in the redox Tafel slope was witnessed near zero in the case of Fe 2+ and optimum conditions indicating the simultaneous oxidation and reduction reactions facilitating the availability of higher number of protons through metabolite inter-conversions that can make H 2. The presence of divalent cations at an optimum concentration will enhance the H 2 production capability of the biocatalyst. However, elevated levels of metal concentration showed a negative influence on the biocatalyst efficiency. This journal is © 2012 The Royal Society of Chemistry.


Badrinarayan P.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology
Journal of Molecular Graphics and Modelling | Year: 2012

In this work, we introduce the development and application of a three-step scoring and filtering procedure for the design of type II p38 MAP kinase leads using allosteric fragments extracted from virtual screening hits. The design of the virtual screening filters is based on a thorough evaluation of docking methods, DFG-loop conformation, binding interactions and chemotype specificity of the 138 p38 MAP kinase inhibitors from Protein Data Bank bound to DFG-in and DFG-out conformations using Glide, GOLD and CDOCKER. A 40 ns molecular dynamics simulation with the apo, type I with DFG-in and type II with DFG-out forms was carried out to delineate the effects of structural variations on inhibitor binding. The designed docking-score and sub-structure filters were first tested on a dataset of 249 potent p38 MAP kinase inhibitors from seven diverse series and 18,842 kinase inhibitors from PDB, to gauge their capacity to discriminate between kinase and non-kinase inhibitors and likewise to selectively filter-in target-specific inhibitors. The designed filters were then applied in the virtual screening of a database of ten million (10 7) compounds resulting in the identification of 100 hits. Based on their binding modes, 98 allosteric fragments were extracted from the hits and a fragment library was generated. New type II p38 MAP kinase leads were designed by tailoring the existing type I ATP site binders with allosteric fragments using a common urea linker. Target specific virtual screening filters can thus be easily developed for other kinases based on this strategy to retrieve target selective compounds. © 2012 Elsevier Inc.


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.


Venkata Mohan S.,Indian Institute of Chemical Technology | Lenin Babu M.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2011

Variation in the dehydrogenase (DH) activity and its simultaneous influence on hydrogen (H 2) production, substrate degradation rate (SDR) and volatile fatty acid (VFA) generation was investigated with respect to varying poised potential in single chambered membrane-less microbial electrolysis cell (MEC) using anaerobic consortia as biocatalyst. Poised potential showed significant influence on H 2 production and DH activity. Maximum H 2 production was observed at 1.0V whereas the control system showed least H 2 production among the experimental variations studied. DH activity was observed maximum at 0.6V followed by 0.8, 0.9 and 1.0V, suggests the influence of poised potential on the microbial metabolism. Almost complete degradation of substrate was observed in all the experimental conditions studied irrespective of the applied potential. Experimental data was also analysed employing multiple regression analysis and 3D-surface plots to find out the best theoretical poised potential for maximum H 2 production and DH activity. © 2011 Elsevier Ltd.


Velvizhi G.,Indian Institute of Chemical Technology | Venkata Mohan S.,Indian Institute of Chemical Technology
International Journal of Hydrogen Energy | Year: 2012

Relative change in the electrogenic activity and potential losses during electron transfer in microbial fuel cell (MFC) was elucidated using real-field recalcitrant pharmaceutical wastewater as anolyte by varying substrate/organic load (OL1, 1.98; OL2, 3.96; OL3, 5.93, OL4, 7.98 kg COD/m3). Increase in organic load showed improvement in electrogenic activity (OL4: 346 mV, 205.61 mW/m2; OL3: 320 mV, 158.58 mW/m2; OL2: 290 mV, 112.87 mW/m2; OL1: 256 mV, 72.60 mW/m2). Both activation and ohmic losses showed decrement with increase in organic load while concentration losses depicted increment. Improvement in power output was non-linear with increase in organic load due to the anodic over potentials, described as electron transfer resistances and potential losses. Bio-electrochemical analysis also depicted the electron losses in terms of electron discharge and energy generation with the function of varying organic load. © 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights.


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.


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.


Venkata Mohan S.,Indian Institute of Chemical Technology | Srikanth S.,Indian Institute of Chemical Technology
Bioresource Technology | Year: 2011

Microbially catalyzed treatment of wastewater was evaluated in both the anode and cathode chambers in dual chambered microbial fuel cell (MFC) under varying biocathode microenvironment. MFC operation with aerobic biocathode showed significant increment in both TDS (cathode, 90.2 ± 1%; anode, 39.7 ± 0.5%) and substrate (cathode, 98.07 ± 0.06%; anode, 96.2 ± 0.3%) removal compared to anaerobic biocathode and abiotic cathode operations (COD, 80.25 ± 0.3%; TDS, 30.5 ± 1.2%). Microbially catalyzed reduction of protons and electrons at cathode will be higher during aerobic biocathode operation which leads to gradual substrate removal resulting in stable bio-potential for longer periods facilitating salts removal. Bio-electro catalytic behavior showed higher exchange current density during aerobic biocathode operation resulting in induced electrochemical oxidation which supports the enhanced treatment. Anaerobic biocathode operation depicted relatively less TDS removal (anode, 16.35%; cathode, 16.04%) in both the chambers in spite of good substrate degradation (anode, 84%; cathode, 87.39%). Both the chambers during anaerobic biocathode operation competed as electron donors resulting in negligible bio-potential development. © 2011 Elsevier Ltd.


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.


Radha Krishna P.,Indian Institute of Chemical Technology | Rao T.J.,Indian Institute of Chemical Technology
Organic and Biomolecular Chemistry | Year: 2010

A convergent stereoselective total synthesis of decarestrictine I (1) and botryolide B (1a) invoking a common synthetic strategy is reported. The key steps are: ring-closing metathesis of epoxy dienoic esters obtained through the Yamaguchi esterification of their respective intermediates to furnish the respective Z-macrocycles (2 and 2a) which were further extrapolated to their respective targets. © The Royal Society of Chemistry 2010.


Kamal A.,Indian Institute of Chemical Technology
Mini reviews in medicinal chemistry | Year: 2010

One of the hallmarks of cancer is the uncontrolled cell proliferation which causes more deaths among the human diseases throughout the globe. One in eight deaths worldwide are due to cancer, it is the second and third leading cause of death in economically developed and developing countries, respectively. As it is caused by both external and internal factors, a balanced approach to cancer control includes prevention, early detection, and effective treatment. In the treatment of cancer, chemotherapy is one of the practical methods and is widely used employing drugs that can destroy cancer cells by impeding their growth and reproduction. Despite the great strides made in the treatment of cancer over the past 50 years, it continues to be a major health concern and therefore, extensive efforts have been devoted to search for new scaffolds to develop chemotherapeutics. In this perspective, over the past two decades from this laboratory extensive efforts have been made in the development of new chemotherapeutic agents for the treatment of cancer. In this review, glimpses on types of current chemotherapeutic agents based on their action of inhibition and the new molecules that are being developed based on the scaffolds such as pyrrolo[2,1-c][1,4]benzodiazepines, podophyllotoxins, benzothiadiazine 1,1-dioxides, naphthalimides and monastrol across the world as well as in this laboratory have been articulated.


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.


Padiya R.,Indian Institute of Chemical Technology | Banerjee S.K.,Indian Institute of Chemical Technology
Recent Patents on Food, Nutrition and Agriculture | Year: 2013

This article reviews recent literature on the usage and relevance of garlic and its bioactive components in controlling diabetes and diabetes-associated pathologies; and also updates recent patents on the subject. Antidiabetic effect of garlic is well documented even in ancient medical literature. Garlic and its active ingredients have been extensively studied for their antidiabetic efficacies in either experimentally induced or genetic animal models of diabetes. Human studies are also available where hypoglycemic effect of garlic was reported. The beneficial effects of garlic are mainly attributed to the presence of volatile sulfur compounds like alliin, allicin, diallyl disulfide, diallyl trisulfide, diallyl sulfide, S-allyl cysteine, ajoene and allyl mercaptan. Garlic and garlic extracts have been shown to be effective in reducing insulin resistance. Therefore, considering the importance of garlic in controlling diabetic complications, several preparations and food processes containing garlic have been patented. This review discusses some of the recent progresses made in this field and consolidates the results. © 2013 Bentham Science Publishers.


Koti Reddy Ch.,Indian Institute of Chemical Technology | Shailaja D.,Indian Institute of Chemical Technology
Journal of Applied Polymer Science | Year: 2015

A simple and facile method was established of incorporating polytetrafluoroethylene (PTFE) on to polyurethane (PU) to improve hydrophobicity of PU by incorporating low levels of fluorine at a molecular level. Nanocomposites were made by preparing PU in the presence of PTFE using seeded miniemulsion polymerization method. The resulting PTFE/PU nanocomposites were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrometry, differential scanning calorimetric, and thermo gravimetric analysis (TGA). FTIR and TEM indicated changes observed in their structure, size and morphology. The water contact angle of PTFE/PU nanocomposite films increased with increasing amount of PTFE and more on blending with silica nanoparticles but a slight decrease in thermal stabilities of SiO2/PTFE/PU nanocomposites were noticed. The hydrophobicity imparted by PTFE to PU surface was found to be at its best for 1: 2 PTFE/PU latex film. © 2015 Wiley Periodicals, Inc.


Reddy C.R.,Indian Institute of Chemical Technology | Dharmapuri G.,Indian Institute of Chemical Technology
Synthesis (Germany) | Year: 2013

An efficient synthesis of the highly stereogenic centered C10-C18 fragment of iriomoteolide-3a has been accomplished. Key steps include Sharpless asymmetric dihydroxylation and epoxidation for generation of the desired stereocenters. © Georg Thieme Verlag Stuttgart · New York.


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.


Purushotham U.,Indian Institute of Chemical Technology | Sastry G.N.,Indian Institute of Chemical Technology
Theoretical Chemistry Accounts | Year: 2012

Conformational analysis of tyrosine (YN) and its ionized counter parts cations (YC), anions (YA) and biologically relevant zwitterionic form (YZ) has been carried out. An exhaustive and systematic exploration of l-tyrosine dimer (YD) conformations resulted in about 59 distinct minima on the potential energy surface. The hydrogen bonds and a variety of non-covalent interactions such as OH-π, NH-π, CH-π, CH-O and π-π interactions stabilized the different forms of tyrosine and its dimers. Atoms in molecules analysis was performed to evaluate the nature and strength of the non-covalent interactions. Over all the NH-O, hydrogen bonds have showed higher stability than other non-covalent interactions in this study. The most stable dimers predominantly possess hydrogen bonding interactions, while the ones with aromatic side chain interactions are less stable. A delicate balance of non-covalent interactions governed the stability of different forms of tyrosine and its dimers. © 2012 Springer-Verlag.


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 |