Design,Synthesis, and Anti-Proliferative Activity of Some New Quinoxaline-1,3,4-oxadiazole Sulfonamide Hybrids

Russian Journal of General Chemistry - In the current study, some new quinoxaline linked 1,3,4-oxadiazole sulfonamide hybrids have been designed, synthesized and characterized by IR, 1H and 13C...     

Fructose-selective calorimetric biosensor in flow injection analysis

A highly selective, interference free biosensor for the measurement of fructose in real syrup samples was developed. The assay is based on the phosphorylation of d(−)fructose to fructose-6-phosphate by hexokinase and subsequent conversion of fructose-6-phosphate to fructose-1,6-biphosphate by fructose-6-phosphate-kinase. The heat liberated in the second reaction is monitored using an enzyme thermistor. The major advantages of this biosensor are rapid and selective measurement of fructose without the need to eliminate glucose and inexpensive FIA-based, mediator-free calorimetric measurement suitable for regular fructose analysis. This method was optimised for parameters, such as pH, ionic strength, interference, operational stability and shelf life. Good and reproducible linearity (0.5-6.0 mM) with a detection limit of 0.12 mM was obtained. Fructose determination in commercial syrup samples and spiked samples confirmed the reliability of this set-up and technique. The biosensor gave reproducible results with good overall stability for continuous measurements over a period of three months besides a useful shelf life of six months. The method could be used for routine fructose monitoring in food samples.     

Influence of backbone conformation on protein aggregation

Effect(s) of organic solvents on an all beta-sheet protein are investigated to understand the influence of backbone conformation on protein aggregation. Results obtained in the present study reveal that protein aggregation is accompanied by the formation of non-native beta-sheet conformation. In contrast, induction of non-native helical segments in the protein is found to inhibit aggregation. The differential effects of the secondary structures on protein aggregation are proposed to stem from the disparity in the nature of the hydrogen bonds and packing of the side chains of hydrophobic residues in the beta-sheet and alpha-helix conformation. In our opinion, the results of the present study provide useful hints to develop methods to alleviate the problems of both in vitro and in vivo protein aggregation.     

Design,Synthesis, and Anti-Proliferative Activity of Some New Quinoxaline Containing 1,2,4-Thiadiazoles Amide Hybrids

Russian Journal of General Chemistry - A series of new quinoxaline-1,2,4-thiadiazoles amide hybrids has been synthesized and evaluated for their anti-proliferative activity on four different human...