Synthesis and urease inhibitory activities of benzophenone semicarbazones/thiosemicarbazones

Twenty-five benzophenone semicarbazones and thiosemicarbazones 3-27 were synthesized starting from benzophenones via hydrazones treated with different aryl isocyanates and isothiocyantes under reflux. All synthetic derivatives were evaluated for their urease inhibitory potential. Good to moderate inhibition trend against urease was observed with the IC50 values in the range of 8.7-119.5 A mu M, when compared with the standard thiourea (IC50 = 21.2 A +/- 1.3 A mu M). Compound 15 showed better inhibition than the standard having the IC50 value of 8.7 A +/- 0.6 A mu M. Compounds 3, 4, 8, 11-14, 16, and 17 with the IC50 values within the range of 26.1 to 43.6 A mu M, demonstrated good to moderate activities while compound 9 (IC50 = 119.5 A +/- 1.6 A mu M) displayed very weak activity. The enzyme kinetic studies on the most active compounds 15 and 17 were performed to deduce their modes of inhibition and dissociation constants K (i).