Structure elucidation of two triterpenoid tetrasaccharides from Androsace saxifragifolia

Abstract

Saxifragifolins A and B, two new triterpenoid tetrasaccharides isolated from the aerial part of Androsace saxifragifolia, were respectively shown to be androsacenol-3-O-{β-D-xylopyranosyl-(1 → 2)-β-D-glucopyranosyl-(1 → 4)-[β-D-glucopyranosyl-(1 → 2)]-α-L-arabinopyranoside}(1) and cyclamiretin A 3-O-{β-D-xylopyranosyl-(1 → 2)-β-D-glucopyranosyl-(1 → 4)-[β-D-glucopyranosyl-(1 → 2)]-α-L-arabinopyranoside}(2). The structural details were elucidated by a combination of fast-atom-bombardment mass spectrometry, chemical degradation, and one- and two-dimensional n.m.r. spectroscopy.