The structures of four novel C31-secodammarane-type triterpenoid saponins from the female flowers of Alnus serrulatoides

Abstract

Four novel C₃₁-secodammarane-type triterpenoid saponins (1)–(4), in addition to the recently structurally elucidated alnustic acid (9), were isolated from the female flowers of Alnus serrulatoides. On the basis of their physico-chemical data, these saponins were characterized as the 12-O-(2′-O-acetyl)-α-L-arabinofuranoside, the 12-O-α-L-arabinofuranoside, the 12-O-β-D-xylopyranoside, and the 12-O-β-D-glucopyranoside of alnustic acid, respectively.