Three new triterpene saponins from two species of Carpolobia

Three new acetylated triterpene saponins 1-3 were isolated from the roots of Carpolobia alba and C. lutea. Their structures were established mainly by 2D NMR techniques as 3-O-β-D-glucopyranosyl-presenegenin-28-O-β-D-galactopyranosyl- (1→4)-[β-D-xylopyranosyl-(1→3)]-β-D-xylopyranosyl- (1→4)-α-L-rhamnopyranosyl-(1→2)-(3,4-di-O-acetyl)-β -D-fucopyranosyl ester, 3-O-β-D-glucopyranosylpresenegenin-28-O-β-D-galactopyranosyl- (1→4)-[α-L-arabinopyranosyl-(1→3)]-β-D-xylopyranosyl- (1→4)-α-L-rhamnopyranosyl-(1→2)-(3,4-di-O-acetyl)-β -D-fucopyranosyl ester, and 3-O-β-D-glucopyranosylpresenegenin-28-O-β-D-xylopyranosyl- (1→4)-[β-D-apiofuranosyl-(1→3)]-α-L-rhamnopyranosyl- (1→2)-(3,4-di-O-acetyl)-β-D-fucopyranosyl ester, respectively.