Inhibitors of xanthine oxidase from the flowers and buds of Daphne genkwa.

Abstract

Xanthine oxidase (XO) inhibitors were isolated from the flowers and buds of Daphne genkwa SIEB. et ZUCC. (Thymelaeaceae) and were identified as genkwanin (1), apigenin (2), luteolin 7-methyl ether (3) and luteolin (4). Compounds 2 and 4 showed particularly strong inhibitory activity against XO. The modes of inhibition by 2 and 4 with respect to xanthine as a substrate were of mixed type. This is the first report of isolation of 3 and 4 from these flowers and buds.