Two new flavonoid glycosides from Diphylleia sinensi

Five flavonoid glycosides were isolated from the methanol and ethyl acetate fractions of the ethanol extract of Diphylleia sinensi by using various chromatographic methods, including silica gel, MCI gel, Sephadex LH-20, ODS and semi-preparative HPLC. The structures of the isolated compounds were identified as diphyflavonoid A (1), diphyflavonoid B (2), quercetin-3-O-β-D-glucopyranoside (3), kaempferol-3-O-β-D-glucopyranoside (4), kaempferol-3-O-(6″-O-acetyl)-β-D-glucopyranoside (5) by spectroscopy methods (1D NMR, 2D NMR, UV, IR, and MS). Compounds 1 and 2 were two new flavonoid glycosides, and compounds 3 and 5 were isolated from the genus Diphylleia for the first time.