Design, synthesis and bioevaluation of 2-mercapto-6-phenylpyrimidine-4-carboxylic acid derivatives as potent xanthine oxidase inhibitors

Abstract A series of 2-mercapto-6-phenylpyrimidine-4-carboxylic acid derivatives ( 7a‒c , 8a‒e , 9a‒e and 10a‒e ) as novel xanthine oxidase inhibitors were designed based on molecular docking, and synthesized by a new method using ketoenol acids and thiourea as the starting materials. In vitro activity assay indicated that most of the designed compounds displayed submicromolar inhibitory potency. Specifically, compound 9b had the most potent enzyme inhibitory activity with the IC 50 at 0.132 μM. Steady-state enzyme kinetics indicated that 9b behaved as a mixed-type inhibitor for XO.