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-beta-D-glucopyranosylpresenegenin-28-O-beta-D-galactopyranosyl-(1-->4)- beta-D-xylopyranosyl-(1-->3)1-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-(3,4-di-O-acetyl)-beta-D-fueopyranosyl ester, 3-O-beta-D-glucopyranosylpresenegenin-28-O-beta-D-galactopyranosyl-(1-->4)- [alpha-L-arabinopyranosyl-(1-->3)1-beta-D-xylopyranosyl-(1-->4)-a-L-rhamnopyranosyl-(1-->2)-(3,4-di-O-acetyl)- beta-D-fucopyranosyl ester, and 3-O-beta-D-glucopyranosylpresenegenin-28-O-beta-D-xylopyranosyl-(1-->4)- [beta-D-apiofuranosyl-(1-->3)]-alpha-L-rhamnopyranosyl-(1-->2)-(3,4-di-O-acetyl)-beta-Dfucopyranosyl ester, respectively.