Madhavan S.,Indian National Institute for Interdisciplinary Science and Technology |
Shanmugam P.,CSIR - Central Leather Research Institute
Organic Letters | Year: 2011
Activated alkene dependent one-pot, three-component aza-Morita-Baylis- Hillman (aza-MBH) reaction of ferrocenealdehyde afforded simple aza-MBH adduct of ferrocenealdehyde, unusual piperidine, β-amino acid residue, and γ-ketoester derivatives of ferrocene in good yield. The synthetic protocol with MVK has led to an unexpected ferrocenyl piperidine derivative in an excellent yield via diastereoselective domino aza-Michael/double Aldol pathway. Plausible mechanisms for the formation of unusual products and diastereoselectivity have also been described. The products can be used for the concise synthesis of ferrocenyl nitrogen heterocycles and bioconjugates. © 2011 American Chemical Society.
Krishnaswamy V.R.,CSIR - Central Leather Research Institute |
Korrapati P.S.,CSIR - Central Leather Research Institute
Scientific Reports | Year: 2014
Re-epithelialization is a key event in wound healing and any impairment in that process is associated with various pathological conditions. Epidermal keratinocyte migration and proliferation during re-epithelialization is largely regulated by the cytokines and growth factors from the provisional matrix and dermis. Extracellular matrix consists of numerous growth factors which mediate cell migration via cell membrane receptors. Dermatopontin (DPT), a non-collagenous matrix protein highly expressed in dermis is known for its striking ability to promote cell adhesion. DPT also enhances the biological activity of transforming growth factor beta 1 which plays a central role in the process of wound healing. This study was designed to envisage the role of DPT in keratinocyte migration and proliferation along with its mRNA and protein expression pattern in epidermis. The results showed that DPT promotes keratinocyte migration in a dose dependant fashion but fail to induce proliferation. Further, PCR and immunodetection studies revealed that the mRNA and protein expression of DPT is considerably negligible in the epidermis in contrast to the dermis. To conclude, DPT has a profound role in wound healing specifically during re-epithelialization by promoting keratinocyte migration via paracrine action from the underlying dermis.
Nethaji S.,CSIR - Central Leather Research Institute |
Sivasamy A.,CSIR - Central Leather Research Institute
Chemosphere | Year: 2011
Chemically prepared activated carbon material derived from palm flower was used as adsorbent for removal of Amido Black dye in aqueous solution. Batch adsorption studies were performed for the removal of Amido Black 10B (AB10B), a di-azo acid dye from aqueous solutions by varying the parameters like initial solution pH, adsorbent dosage, initial dye concentration and temperature with three different particle sizes such as 100μm, 600μm and 1000μm. The zero point charge was pH 2.5 and the maximum adsorption occurred at the pH 2.3. Experimental data were analyzed by model equations such as Langmuir, Freundlich and Temkin isotherms and it was found that the Freundlich isotherm model best fitted the adsorption data and the Freundlich constants varied from (KF) 1.214, 1.077 and 0.884 for the three mesh sizes. Thermodynamic parameters such as ΔG, ΔH and ΔS were also calculated for the adsorption processes and found that the adsorption process is feasible and it was the endothermic reaction. Adsorption kinetics was determined using pseudo first-order, pseudo second-order rate equations and also Elovich model and intraparticle diffusion models. The results clearly showed that the adsorption of AB10B onto lignocellulosic waste biomass from palm flower (LCBPF) followed pseudo second-order model, and the pseudo second-order rate constants varied from 0.059 to 0.006 (gmg-1min) by varying initial adsorbate concentration from 25mgL-1 to 100mgL-1. Analysis of the adsorption data confirmed that the adsorption process not only followed intraparticle diffusion but also by the film diffusion mechanism. © 2010 Elsevier Ltd.
Bharathi D.G.,CSIR - Central Leather Research Institute
Scientometrics | Year: 2011
The criteria for the evaluation of scientific journals have changed from characteristics of its contents to citations of articles. Among many problems associated with citation-based evaluation methods are that it is applicable only to a limited number of journals, preferential selection of citable documents, differential values to citations, time duration for assessment, etc. The proposed index, Aggregated Citations of Cited Articles (ACCA), is calculated based on citations data, derived from only of cited articles, and therefore can be validated from standard database. While giving more importance to citations, the number of cited articles published in a journal also has some influence in the new index. The calculated values are consistent with time and can be used to back-track the status of a journal in its past and for continued evaluation. The new Index ensures neutrality, qualitative and quantitative hierarchy and consistency in the estimation of journal ranking. © 2010 Akadémiai Kiadó, Budapest, Hungary.
Karthikeyan S.,CSIR - Central Leather Research Institute |
Sekaran G.,CSIR - Central Leather Research Institute
Physical Chemistry Chemical Physics | Year: 2014
The objective of this investigation is to evaluate the hydroxyl radical (OH) generation using nanoporous activated carbon (NPAC), derived from rice husk, and dissolved oxygen in water. The in situ production of the OH radical was confirmed through the DMPO spin trapping method in EPR spectroscopy and quantitative determination by a deoxyribose assay procedure. NPAC served as a heterogeneous catalyst to degrade 2-deoxy-d-ribose (a reference compound) using hydroxyl radical generated from dissolved oxygen in water at temperatures in the range 313-373 K and pH 6, with first order rate constants (k = 9.2 × 10-2 min-1, k = 1.2 × 10-1 min -1, k = 1.3 × 10-1 min-1 and k = 1.68 × 10-1 min-1). The thermodynamic constants for the generation of hydroxyl radicals by NPAC and dissolved oxygen in water were ΔG -1.36 kJ mol-1 at 313 K, ΔH 17.73 kJ mol-1 and ΔS 61.01 J mol-1 K-1. This journal is © 2014 the Owner Societies.
Nandakumar A.,CSIR - Central Leather Research Institute |
Perumal P.T.,CSIR - Central Leather Research Institute
Organic Letters | Year: 2013
Tetrasubstituted olefin based new xanthene derivatives have been synthesized via palladium-catalyzed carbopalladation/C-H activation of 2-bromobenzyl-N-propargylamine derivatives. The synthesized compounds display a pronounced solid state fluorescence due to their restricted internal rotation of a C-Ar bond in the solid or aggregation state. © 2013 American Chemical Society.
Nethaji S.,CSIR - Central Leather Research Institute |
Sivasamy A.,CSIR - Central Leather Research Institute |
Mandal A.B.,CSIR - Central Leather Research Institute
Bioresource Technology | Year: 2013
Activated carbon prepared from corn cob biomass, magnetized by magnetite nanoparticles (MCCAC) was used for the adsorption of hexavalent chromium from aqueous solution. The adsorbent was characterized by SEM, TEM, XRD, VSM, surface functionality and zero-point charge. The iron oxide nanoparticles were of 50. nm sizes and the saturation magnetization value for the adsorbent is 48.43. emu/g. Adsorption was maximum at pH 2. Isotherm data were modeled using Langmuir, Freundlich and Temkin isotherm. The prepared MCCAC had a heterogeneous surface. The maximum monolayer adsorption capacity was 57.37. mg/g. Kinetic studies were carried out and the data fitted the pseudo second-order equation. The mechanism of the adsorption process was studied by incorporating the kinetic data with intraparticle diffusion model, Bangham equation and Boyd plot. The adsorption was by chemisorption and the external mass transfer was the rate-determining step. A micro column was designed and the basic column parameters were estimated. © 2013 Elsevier Ltd.
Krishnamoorthy G.,CSIR - Central Leather Research Institute
Journal of biomaterials science. Polymer edition | Year: 2013
This work discusses the preparation and characterization of novel collagen scaffolds by using unnatural D-amino acids (Coll-D-AAs)-assisted 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/N-hydroxyl succinimide(NHS)-initiated crosslinking. The mechanical strength, hydrothermal and structural stability, resistance to biodegradation and the biocompatibility of Coll-D-AAs matrices were investigated. The results from Thermo mechanical analysis, Differential scanning calorimetric analysis and Thermo gravimetric analysis of the Coll-D-AAs matrices indicate a significant increase in the tensile strength (TS, 180±3), % elongation (% E, 80±9), elastic modulus (E, 170±4) denaturation temperature (T d, 108±4) and a significant decrease in decomposition rate (Tg, 64±6). Scanning electron microscopic and Atomic force microscopic analyses revealed a well-ordered with properly oriented and well-aligned structure of the Coll-D-AAs matrices. FT-IR results suggest that the incorporation of D-AAs favours the molecular stability of collagen matrix. The D-AAs stabilizing the collagen matrices against degradation by collagenase would have been brought about by protecting the active sites in collagen. The Coll-D-AAs matrices have good biocompatibility when compared with native collagen matrix. Molecular docking studies also indicate better understanding of bonding pattern of collagen with D-AAs. These Coll-D-AAs matrices have been produced in high mechanical strength, thermally and biologically stable, and highly biocompatible forms that can be further manipulated into the functional matrix suitable in designing scaffolds for tissue engineering and regenerative medical applications.
Raghavan K V.,CSIR - Central Leather Research Institute
Lipids in health and disease | Year: 2010
BACKGROUND: Frog skin has been sequentially and scientifically evaluated by our group for its wound healing efficiency. Owing to the complex structure of skin, attempts were being made to analyse the role of individual constituents in different phases of healing. Our earlier papers have shown the significance of frog skin not only in wound healing but also enhancing the proliferating activity of the epidermal and dermal cells which are instrumental for normal healing process. We also have identified for the first time novel antimicrobial peptides from the skin of Rana tigerina and thereby reduce the complications involved in the sepsis. PURPOSE OF THE STUDY AND RESULTS: The current study envisages the role of frog skin lipids in the inflammatory phase of wound healing. The lipid moiety of the frog skin dominated by phospholipids exhibited a dose dependent acceleration of healing irrespective of the mode of application. The efficiency of the extract is attributed partially to the anti-inflammatory activity as observed by the histochemical and immunostimulatory together with plethysmographic studies. CONCLUSIONS: Thus, frog skin for the first time has been demonstrated to possess lipid components with pharmaceutical and therapeutic potential. The identification and characterization of such natural healing molecules and evaluating their mechanism of action would therefore provide basis for understanding the cues of Nature and hence can be used for application in medicine.
Kiruthika S.E.,CSIR - Central Leather Research Institute |
Perumal P.T.,CSIR - Central Leather Research Institute
Organic Letters | Year: 2014
A Cu(I)-catalyzed, intermolecular protocol for the synthesis of 2-amidoindoles and tetrahydroindolo[1,2-a]quinazolines in shorter time and high yields is reported. The key highlight of this disclosure is the formation of 2-amidoindole and tetrahydroindolo[1,2-a]quinazoline moieties directly from gem-dibromovinylanilides and sulfonamides in a one-pot fashion through the in situ formation of ynamides followed by a base-promoted intramolecular hydroamidation. © 2013 American Chemical Society.