Three new saponins from the leaves of Hovenia dulcis(Rhamnaceae)

Abstract

The carbohydrate sequences of three new saponin, saponin C₂(1a), D (2a), and G (3a), obtained from the leaves of Hovenia dulcis Thunb. (Rhamnaceae), have been identified, mainly by ¹³C n.m.r. spectroscopy, and the full molecular structures of these saponins have been assigned as 3-O-(2-O-α-L-rhamnopyranosyl-3-O-β-D-glucopyranosyl -α-L-arabinopyranosyl)jujubogenin, 3-O-(2-O-α-L-rhamnopyranosyl-β-D-glucopyranosyl)-20-O-α-L-rhamnopyranosyljujubogenin, and 3-O-β-D-glucopyranosyl-20-O-α-L-rhamnopyranosyljujubogenin, respectively, from additional chemical and spectroscopic evidence.