Synthesis, characterization of pyrazole derivatives by using benzoyl glycine methyl ester as starting material: DNA binding and biological studies

Abstract

Four pyrazole derivatives{Methyl-2-benzamido-2-(1,3,5-trimethyl-1H-pyrazol-4-yl)acetate (1A), 2-(benzamido)-2- (1,3,5-trimethyl-1H-pyrazol-4-yl)acetohydrazide (1B), Methyl-2-benzamido-2-(3,5-dimethyl-1H-pyrazol-4-yl)acetate (2A), 2-(benzamido)-2-(3,5-dimethyl-1H-pyrazol-4-yl)acetohydrazide (2B)}were synthesized by the solvent free method and their DNA binding interaction were studied by using UV-Visible spectroscopy and verified by viscometric technique under physiological conditions of pH (stomach; 4.7, blood; 7.4) and temperature (37 oC; (human body
temperature). All the compounds exhibited strong binding with the DNA due to the formation of compound–DNA complex via intercalation. Among all the compounds 2B showed greater binding at pH 7.4 as evident from their greater Kb (5.32 × 104 M). Overall binding data revealed greater binding affinity of all the compounds with DNA at blood p
H. Viscosity studies further verified the intercalation mode of interaction of these compounds with DNA. Standard Gibb’s free energy changes (∆G) were evaluated negative and indicated spontaneous binding of compounds with DNA. Biological studies revealed greater cytotoxicity activity of 1A and 2B with least LD50 values of 170 μg/mL and 171μg/mL, respectively, while all the compounds showed broader range of antibacterial activity with MIC values
ranging from 150-200 gL -1. None of the compounds showed significant antioxidant activity