Triterpenoid saponins and phenylethanoid glycosides from stem of Akebia trifoliata var. australis.

A detailed phytochemical study on the 70% aqueous ethanol extract of stems of Akebia trifoliata (Thunb.) Koidz. var. australis (Diels) Rehd led to isolation of five compounds, together with 12 known triterpenoid saponins and three known phenylethanoid glycosides. The structures of the five compounds were elucidated on the basis of analysis of spectroscopic data and physicochemical properties as: 2alpha, 3beta, 23-trihydroxy-30-norolean-12-en-28-oic acid beta-D-glucopyranosyl ester (1), 2alpha, 3beta, 23-trihydroxy-30-norolean-12-en-28-oic acid beta-D-xylopyranosyl-(1-->3)-O-alpha-D-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl ester (2), 2alpha, 3beta, 23-trihydroxyurs-12-en-28-oic acid beta-D-xylopyranosyl-(1-->3)-O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl ester (3), 3-beta-[(beta-D-glucopyranosyl-(1-->3)-O-alpha-L-arabinopyranosyl)oxy]-23-hydroxy-30-norolean-12-en-28-oic acid alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl ester (4) and 3-beta-[(alpha-L-xylopyranosyl-(1-->2)-O-alpha-L-arabinopyranosyl)oxy]-30-norolean-12-en-28-oic acid alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl ester (5), named mutongsaponin A, B, C, D and E, respectively.