http://nopr.niscpr.res.in/handle/123456789/62509 Sat, 10 Oct 2026 06:39:06 GMT 2026-10-10T06:39:06Z http://nopr.niscpr.res.in/handle/123456789/62522 Title: Gamma degradation studies of chitosan and sodium alginate biopolymers Authors: Bambal, Apurva; Jugade, Ravin; Gomase, Vaishnavi; Shekhawat, Anita; Sarvanan, D Abstract: Various biopolymers have been reported to play very important roles in different fields including pharmaceutical sciences, water treatment as well as nanosciences. The properties of these biopolymers are widely affected by their molecular weight, structural and functional moieties on them. In order to improve the efficiency towards desired application, they are subjected to chemical and physical processes. One of them is radiation induced degradation or crosslinking. Radiation has been reported as one of the methods for modification of polysaccharides. In this study, chitosan and sodium alginate have been degraded using gamma radiation from 60Co source with dose rate of 4.295 kGy/h, with doses upto100 kGy. The molecular weights have been determined by viscosity method. Similarly, both have been subjected to various characterization methods such as TGA-DTA, XRD, FTIR, SEM-EDX, UV-Vis and DDA (degree of deacetylation). Radiation induced degradation is confirmed through reduction in molecular weight with respect to gamma dose. Basic advantage of radiation degradation of biopolymers includes ability to promote changes in a reproducible manner, quantitatively and without introduction of chemical agents. The highlight of gamma irradiation of biopolymer is that there is no chemical waste generation. Page(s): 899-905 Fri, 01 Sep 2023 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/62522 2023-09-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/62521 Title: Synthesis, spectral, crystal, computational studies and antimicrobial activities of (E)-N-(substituted arylidene)-3-(trifluoromethyl)anilines Authors: Dineshkumar, N; Muthuvel, I; Thirunarayanan, G Abstract: A series of (E)-N-(substituted arylidene)-3-(trifluoromethyl) anilines have been synthesised by ZnFe2O4 catalyzed microwave promoted condensation of 3-trifluoromethyl aniline and various aryl aldehydes. This condensation gives more than 90% yield of products. The synthesised imines have been characterized by their analytical, micro analysis and spectroscopic data. From single crystal X-ray analysis, the structure of [(E)-N-(naphthalene-1-ylmethylene)-3- (trifluoromethyl) aniline has been established. The optimized geometrical structures, molecular electrostatic potential and FMO studies of these amines have been investigated by DFT theoretical-computational method. The Mulliken charge analysis of these amines have been predicted. In vitro antimicrobial activities of prepared imines have been assessed using Bauer-Kirby disc diffusion method. Page(s): 906-920 Fri, 01 Sep 2023 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/62521 2023-09-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/62520 Title: Vegetable oil-based ethanolamides as potential anti-oxidant additives for lubricant formulations Authors: Kotte, Kamalakar; Azmeera, Thirupathi; Prasad, R B N; Karuna, M S L Abstract: Novel antioxidant mono- and diethanolamide, eight additives have been prepared from castor oil, coconut oil, thumba oil and sal fat. These have been evaluated for antioxidant efficacy taking epoxy karanja oil as base oil at 0.5-5% concentration. Antioxidant tests have been performed on Rotating Pressure Vessel Oxidation Test RPVOT and Differential Scanning Calorimetry DSC. Among the prepared mono and diethanolamides, only diethanolamide-based additives have exhibited potential anti-oxidant behavior. Coconut diethanolamides containing saturated medium chain fatty acids have exhibited excellent stabilities, followed by diethanolamides of sal rich containing saturated long chain fatty acids. The castor based diethanolamides, which are rich in mono unsaturated hydroxy fatty acid show slightly lower stabilities, while thumba with polyunsaturation exhibits poor oxidation stabilities. Both the methods have shown that the fatty diethanolamides exhibit extraordinary stabilities compared to commercial antioxidant, butylated hydroxy toluene BHT at 1-5% concentration. The study indicates that the presence of saturation and medium chain fatty acids in the diethanolamide-based additives improves the oxidation stability of the base oils. Page(s): 921-930 Fri, 01 Sep 2023 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/62520 2023-09-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/62519 Title: Determination of alpha-lipoic acid in pharmaceutical samples using inhibitory kinetic approach in SLS micellar medium Authors: Srivastava, Abhishek; Srivastava, Neetu; Singh, Ruchi Abstract: A novel, repeatable, and swift kinetic approach for determining alpha-lipoic acid (ALA) in sodium lauryl sulfate (SLS) micellar medium has been presented, and it has been connected to ALA determination in drug formulations. The approach is based on ALA inhibitory property. ALA (containing two sulfur atoms) forms a chelate with Pd2+, lowering the effective [Pd(II)], and ultimately, the Pd2+catalyzed cyanide substitution rate from [Fe(CN)6]4− by 4-cyanopyridine (4-CNpy). Fixed times of 5 and 10 min have been chosen under optimal reaction conditions with [4-CNpy] = 2.0 × 10−3 mole dm−3, pH = 3.50 ± 0.02, Temp = 298 ± 0.2 K, I = 0.1 mole dm−3 (NaClO4), [Fe(CN)6 4−] = 1.25 × 10−4 mole dm−3, [Pd+2] = 6.0 × 10−5 mole dm−3, and [SLS] = 7.75 × 10−3 mole dm−3 to calculate the absorbance at 477 nm associated with the final substitution product [Fe(CN)5 4-CNpy]3−. ALA's inhibiting influence on the Pd2+catalyzed cyanide substitution with 4-CNpy from [Fe(CN)6]4−, has been represented by a modified mechanistic approach. The concentration of ALA in various water specimens can be measured at the micro-level down to 1.0 × 10−6 mole dm−3 using the established kinetic spectrophotometric approach. The suggested method is highly reproducible and has been effectively applied to accurately quantify the ALA in pharmaceutical samples. Even as much as 1000 with [ALA], typical additives used in medications do not significantly hinder the determination of ALA. Page(s): 931-939 Fri, 01 Sep 2023 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/62519 2023-09-01T00:00:00Z