A novel icariin type flavonoid from Epimedium pseudowushanense.

A novel icariin type flavonoid glycoside with a malonaldehydic acid intramolecular ester and two known flavonoid glycosides were isolated from Epimedium pseudowushanense. Their structures were elucidated on the basis of spectroscopic analysis and comparison of their data to the values reported in the literatures. The anti-inflammatory activities of these compounds icariin 3'''-O-malonaldehydic acid intramolecular 1'''', 2''' ester (1), icariin (2) and epimedin C (3) were tested. The results indicated that compounds 1, 2 and 3 showed maximal inhibitory ratio of 27.91, 44.80 and 46.61%, respectively in in vitro anti-inflammatory activity on LPS-induced TNF-α secretion in RAW264.7 cells. Compounds icariin (2) and epimedin C (3) were found to inhibit the secretion of TNF-α to a comparable degree as quercetin.