Triterpenoid Saponins from the Stem Bark of Acanthopanax brachypus HARMS

Two new triterpenoid saponins, brachyposide A (1) {3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl-2beta,3beta,16alpha,23-tetrahydroxyolean-12-en-28-oic acid 28-O-beta-D-apiofuranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranosyl ester} and brachyposide B (2) {3-O-beta-D-glucopyranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->3)-beta-D-glucuronopyranosyl-2beta,3beta,23-trihydroxyolean-12-en-28-oic acid 28-O-beta-D-xylopyranosyl-(1-->4)-[beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl ester}, together with four known triterpenoid saponins, including tabguticoside A, nipponoside D, palmatoside E and ciwujianoside A(1), were isolated from the stem bark of Acanthopanax brachypus. Their structures were elucidated on the basis of spectroscopic and chemical evidence.