Two New Triterpenoidal Saponins from Roots of Pachystela msolo

Two new triterpenoidal saponins, pachystelanosides A (1) and B (2), and six known compounds have been isolated from the roots of Pachystela msolo. Their structures were elucidated on the basis of extensive ID and 2D NMR studies ('H, "C, DEPT, COSY, TOCSY, NOESY, HSQC, HMBC), and ESI-MS as 3-O-(β-D-glucopyranosyl-(1-->2)-β-D-apiofuranosyl-(1-->6)-β-D-glucopyranosyl)-28-O-(β-D-xylopyranosyl-(1--4)[α-L-rhamnopyranosyl-(1-->2)}-α-L-arabino- pyranosyl)-hydroxyprotobassic acid (1) and 3-O-(β-D-glucopyranosyl-(1-->2)-β-D-apiofuranosyl-(1-->6)-β-D-glucopyranosyl)-28-O-(β-D-xylopyranosyl- (1-->4)[α-L-rhamnopyranosyl-(1-->2)]-α-L-arabinopyranosyl)-7α-hydroxyprotobassic acid (2).