Chemical constituents in Epimedium sagittatum and their in vitro antitumor activities

Objective To investigate the chemical constituents from Epimedium sagittatum and screen in vitro antitumor activity for 8-prenylated flavonoids.Methods Chemical constituents were isolated and purified by chromatography on silica gel,Sephadex LH-20 colums,and preparative HPLC.Their structures were identified by physicochemical constants and spectroscopic methods.The in vitro antitumor activities of the isolated prenylated compounds were evaluated by MTT assay.Results Seven flavonoids were isolated and their structures were identified as icariin(1),icaritin(2),baohuosideⅠ(3),desmethylicaritin(4),tricin(5),IcarisideⅠ(6),and epimedin C(7).In vitro antitumor results showed that compounds 2-4 and 6 showed the enhanced inhibition on the cell proliferation of human breast cancer cell line MDA-MB-231 in 0.5 — 100 μmol/L with concentration increasing.The IC50 value for 48 h was 12.43,35.44,11.53,and 16.31 μmol/L respectively,the activity of compound 1 and 7 were very weak.Conclusion Compounds 3 and 4 are isolated from E.sagittatum for the first time.Compound 3 is expected to become one of the anti-breast cancer drug candidates.