Xanthine Oxidase Inhibitors from Vietnamese Blumea balsamifera L.

From the MeOH extract of the aerial part of Blumea balsamifera L., a new dihydroflavonol, (2 R ,3 S )‐(−)‐4′‐ O ‐methyldihydroquercetin (1), together with seven known compounds has been isolated. Their structures were elucidated on the basis of spectroscopic data. Compounds 1–4 and 6–8 displayed significant xanthine oxidase inhibitory activity in a concentration‐dependent manner, and compounds 1, 6 and 8 showed more potent inhibitory activity, with IC 50 values ranging from 0.23 to 1.91 µ m , than that of a positive control allopurinol (IC 50 2.50 µ m ). Copyright © 2012 John Wiley & Sons, Ltd.