Identification of Biflavones in Ethyl Acetate Fraction from Ethanol Extract of Selaginella doederleinii Hieron

The chemical constituents were isolated from the ethyl acetate fraction from ethanol extract of Selaginella doederleinii Hieron by column chromatography on silica gel and Sephadex LH-20. The chemical structures of six biflavones were elucidated on the basis of physicochemical properties and spectroscopic data as amentoflavone (1), robustaflavone 7,4',7''-o-trimethyl ether (2), heveaflavone (3), podocarpusflavone A (4), robustaflavone 4',4'''-o-dimethyl ether (5) and robustaflavone 4'-o-methyl ether (6). Biflavones 2, 4 and 5 were obtained from Selaginella doederleinii Hieron for the first time.