http://nopr.niscair.res.in/handle/123456789/72 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/120 Title: Comparative QSAR modeling of COX-2 inhibitor 1,2-diarylimidazoles using E-state and physicochemical parameters <br/> <br/>Authors: Chakraborty, Santanu; Sengupta, Chandana; Roy, Kunal <br/> <br/>Abstract: Considering importance of developing selective COX-2 inhibitors, COX-2 binding affinity data of 4-(2-aryl-1-imidazolyl)-phenyl methyl sulfones and sulfonamides (n = 83) have been modeled using electrotopological state (E-state) index as electronic parameter, hydrophobic substituent constant (π) and molar refractivity (MR) of aryl ring substituents as lipophilic and steric parameters, respectively. Additionally, suitable dummy parameters have been used for the development of multiple regression equations in a stepwise manner. The study suggests that lipophilicity of ortho, meta and para substituents of the aryl ring increases the binding affinity, while molar refractivity (MR) of ortho and meta substituents of the aryl ring decreases the binding affinity. Again, electron-withdrawing substituents at meta and para positions of the aryl ring increase the binding affinity. Additionally, a 4-fluoro substituent on the aryl ring, a trifluoromethyl substituent at R₃ position and simultaneous presence of 3-chloro and 4-methyl groups on the aryl ring are conducive to the binding affinity. Also, an amino substituent is preferred over a methyl group at R₂ position suggesting preference of the sulfonamide moiety over the methyl sulfone moiety for the COX-2 binding affinity. Furthermore, importance of E-state values of different atoms in the generated relations suggests the influence of electron density distribution over the 1,2-diarylimidazole nucleus for the binding affinity. For this data set, E-state parameters perform better as electronic parameters in comparison to Hammett sigma parameters. When lipophilic whole molecular descriptor (ClogP) is used, instead of hydrophobic substituent constant (π), the former performs better than the latter. <br/> <br/>Page(s): 169-175 http://nopr.niscair.res.in/handle/123456789/114 Title: Studies on glucose-metabolizing enzymes in cytosolic and bacteroidal fractions of mungbean (Vigna radiata L.) and lentil (Lens culinaris L.) nodules <br/> <br/>Authors: Munjral, N; Gupta, A K; Kaur, N <br/> <br/>Abstract: Nitrogen is exported in the form of ureides or amides from the nodules in pulse crops. In order to understand the carbon metabolism in ureide and amide exporting nodules, activities of enzymes involved in glucose metabolism were compared in cytosolic and bacteroidal fractions of mungbean (ureide exporter) and lentil (amide exporter) nodules during development. Activities of hexokinase, fructokinase, phosphoglucomutase, fructose-1,6-bisphosphatase, phosphohexose isomerase and UDP-glucose pyrophosphorylase were detected in cytosolic fraction of nodules of both the crops during development. Out of these enzymes, specific activity of phosphohexose isomerase was the highest in nodules of both the crops, in comparison with other enzymes. In comparison with mungbean, activities of various enzymes were less in cytosolic fraction of lentil. Activities of hexokinase, fructokinase, phosphoglucomutase were present only in cytosolic fraction of mungbean (Vigna radiata L.), however, low activity of these enzymes was also observed in lentil (Lens culinaris L.) bacteroids. Activities of phosphohexose isomerase and fructose-1,6-bisphosphatase were higher in bacteroids of lentil, as compared to mungbean during early nodule development, but this pattern was reversed with progress of crop development. Higher activities of phosphoglucomutase and fructose-1,6-phosphatase in mungbean cytosolic fraction could lead to increased flow of carbon towards pentose phosphate pathway. <br/> <br/>Page(s): 186-189 http://nopr.niscair.res.in/handle/123456789/113 Title: Role of pectin from Cucumber (Cucumis sativus) in modulation of protein kinase C activity and regulation of glycogen metabolism in rats <br/> <br/>Authors: Sudheesh, S; Vijayalakshmi, N R <br/> <br/>Abstract: The regulatory role of protein kinase C (PKC) in glycogen metabolism in pectin fed rats was investigated. Administration of pectin (5 g/kg body wt/day) from cucumber (Cucumis sativius L.) led to inhibitory effects on PKC activity in the liver of rats. In the brain and pancreas, PKC activity was significantly higher in pectin-treated rats as compared to the control group. Level of blood glucose was significantly lowered and the level of glycogen in the liver was significantly increased in pectin-administered rats. Glycogen synthase activity was enhanced, while glycogen phosphorylase enzyme showed inhibition in pectin-treated rats. Results indicated that pectin administration might have caused an increase in the secretion of the insulin, which, in turn, had a stimulatory effect on the PKC activity in the pancreas. The decreased PKC activity in the liver and increased PKC activity in the brain and pancreas on pectin administration indicated enhanced glycogenesis and reduced glycogenolysis. <br/> <br/>Page(s): 183-185 http://nopr.niscair.res.in/handle/123456789/112 Title: Estimation of hydrogen sulphide in the human lymphocytes <br/> <br/>Authors: Barathi, S; Vadhana, Prasanna; Angayarkanni, N; Ramakrishnan, S <br/> <br/>Abstract: Hydrogen sulphide (H₂S), a signaling gasotransmitter and a potent vasorelaxant is endogenously produced by the enzymes cystathionine-β-synthase (CBS) and cystathionine-ϒ-lyase (CSE). CBS is a predominant source of H₂S in the central nervous system, while CSE is the major H₂S producing enzyme in the brain and other nervous tissues. Though the expression of these enzymes in the blood lymphocytes is known, H₂S formation in the lymphocytes has not been reported so far. In the present study, H₂S levels in the lymphocytes of healthy control subjects were estimated, after suitable modifications in a routine method [Stipanuk M H & Beck P W (1982) Biochem J 206, 267-277] used for detecting tissue levels of H₂S. In this method, homocysteine (Hcys) due to its higher solubility was used as the substrate in place of L-cysteine and NaOH was used in place of zinc acetate to increase the entrapment of H₂S in the central well. A mean H₂S level of 11.64 ± 6.36 µM/min/mg protein was detected in the lymphocytes of 8 subjects (mean age, 24 ± 2; 2 male, 6 female). The modified method was found to be more sensitive for H₂S estimation in human lymphocytes. As endogenous H₂S is reported to be involved in the pathogenesis of various cardiovascular and pulmonary diseases, the levels of H₂S in lymphocytes can be a marker of the endogenous tissue levels. <br/> <br/>Page(s): 179-182