Triterpene Bisdesmosides from the Stems of Akebia Quinata

Abstract

Five new triterpene saponins (1–5) were isolated from the stems of Akebia quinata. On the basis of extensive spectroscopic analysis, including 2D NMR data, and chemical evidence, the structures of the new compounds were determined to be 3β-[(O-β-D-glucopyranosyl-(1→3)-α-L-arabinopyranosyl)oxy]-29-hydroxyolean-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (1), 3β-[(O-β-D-glucopyranosyl-(1→3)-O-[α-L-rhamnopyranosyl-(1→2)]-α-L-arabinopyranosyl)oxy]-29-hydroxyolean-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (2), 3β-[(O-β-D-glucuronopyranosyl-(1→3)-O-[α-L-rhamnopyranosyl-(1→2)]-α-L-arabinopyranosyl)oxy]-29-hydroxyolean-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (3), 3β-[(O-β-D-glucopyranosyl-(1→3)-α-L-arabinopyranosyl)oxy]-23,29-dihydroxyolean-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (4), and 3β-[(O-β-D-glucopyranosyl-(1→3)-O-[α-L-rhamnopyranosyl-(1→2)]-α-L-arabinopyranosyl)oxy]-23,29-dihydroxy-olean-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (5), respectively.