Triterpenoid saponins of Acanthopanax nipponicus leaves

Five new triterpenoid saponins, nipponosides A-E (1, 3-6), were isolated from Acanthopanax nipponicus leaves, along with a known saponin, kalopanaxsaponin G (2). Nipponosides A-E were characterized as the 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta -D-glucopyranosyl ester of 3-oxohederagenin, oleanolic acid 3-O-beta-D-glucopyranoside, gypsogenin 3-O-beta-D-glucopyranoside, 3beta,23,29-trihydroxyolean-12-en-28-oic acid, and 3beta,20alpha, 23-trihydroxy-30-nor-olean-12-en-28-oic acid, respectively. The structures of these new compounds were based on chemical and spectral methods.