Studies on the Constituents of Leguminous Plants. XII. : The Structures of New Triterpenoid Saponins from Wistaria branchybotrys SIEB. et ZUCC.

Abstract

Four new triterpenoid saponins (wistariasaponins A, B₁, B₂ and C) were isolated as methyl ester forms from the knots of Wistaria brachybotrys (Leguminosae), and their structures were characterized as 3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-xylopyranosyl(1→2)-β-D-glucuronopyranosyl]wistariasapogenol A, 3-O[α-L-rhamnopyranosyl(1→2)-β-D-xylopyranosyl(1→2)-β-D-glucuronopyranosyl]wistariasapogenol B, 3-O-[α-L-rhamnopyranosyl(1→2)-β-D-galactopyranosyl(1→2)-β-D-glucuronopyranosyl]wistariasapogenol B and 3-O-[α-L-rhamnopyranosyl(1→2)-β-D-xylopyranosyl-(1→2)-β-D-glucuronopyranosyl]soyasapogenol B, respectively, on the basis of chemical and physicochemical evidence. The inhibitory effects of these saponins and sapogenols on Epstein-Barr virus activation induced by a tumor promoter were also tested for the primary screening of anti-tumor promoting activities.