Benzoflavone derivatives as potent antihyperuricemic agents.

Two series of benzoflavone derivatives were rationally designed, synthesized and evaluated for their xanthine oxidase (XO) inhibitory potential. Among both series, eight compounds (, , , , , , , and ) were found to exert significant XO inhibition with IC values lower than 10 μM. Enzyme kinetic studies revealed that the most potent benzoflavone derivatives ( and ) are mixed type inhibitors of the XO enzyme.