TRITERPENE SAPONINS FROM PULSATILLA CERNUA

AIM　To investigate the chemical constituents of the roots of Pulsatilla cernua (Thunb.) Bercht. et Opiz. METHODS　Column chromatography (including D101 macroporous resin, silica gel and ODS) and HPLC were used to separate the chemical constituents whose structures were elucidated by FAB-MS, NMR (1D and 2D) and hydrolysis methods. RESULTS　Six compounds were isolated and established as hederagenin 3-O-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranoside (pulsatilla saponin A, 1), hederagenin 3-O-β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranoside(2), hederagenin 3-O-α-L-rhamnopyranosyl(1→2)［β-D-glucopyranosyl(1→4)］-α-L-arabinopyranoside (pulsatilla saponin D, 3), 3-O-α-L-rhamnopyranosyl(1→2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl(1→6)-β-D-glucopyranosyl ester (dipsacoside B, 4), 3-O-α-L-rhamnopyranosyl(1→2) ［β-D-glucopyranosyl(1→4)］-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl ester (cernuoside C, 5) and daucosterol(6), respectively. CONCLUSION　Compound 5 is a new compound and named as cernuoside C. Compounds 2, 4 and 6 were isolated from Pulsatilla cernua for the first time.