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-α-l-rhamnopyranosyl(1→4)-β-d-glucopyranosyl(1→6)-β-d-glucopyranosyl ester of 3-oxohederagenin, oleanolic acid 3-O-β-d-glucopyranoside, gypsogenin 3-O-β-d-glucopyranoside, 3β,23,29-trihydroxyolean-12-en-28-oic acid, and 3β,20α,23-trihydroxy-30-nor-olean-12-en-28-oic acid, respectively. The structures of these new compounds were based on chemical and spectral methods.