Structural studies on some saponins from Lecaniodiscus cupanioides

Four triterpenoid saponins isolated from the stem bark of Lecaniodiscus cupanioides and denoted S-2,S-3,S-4 and S-5, were identified as follows. S-2:3-O-[α- l -arabinopyranosyl-(1→3)-α- l -rhamnopyranosyl-(1→2)-α- l -arabinopyranosyl]-hederagenin; S-3:3-O-[α- d -xylopyranosyl-(1→3)-α- l -rhamnopyranosyl-(1→2)-α- l -arabino-pyranosyl ]-hederagenin; S-4:3-O- [α- l -arabinopyranosyl-(1→3)-α- l -rhamnopyranosyl-(1→ 2)-α- l -arabinopyranosyl]-hederagenin; S-5:3-O- [α- l -rhamnopyranosyl-(1→2)-α- l -arabinopyranosyl ]-hederagenin. Of these, S-2 and S-4 are new substances.