New triterpenoid saponins from Achyrantes aspera LINN.

Two new bisdesmosidic triterpenoid saponins, i.e. 1 and 2, were isolated, b esides the three known saponins 3- 5, from the MeOH extract of the aerial p arts of Achyranthes aspera LINN. (Amaranthaceae). Their structures were elu cidated as beta-D-glucopyranosyl 3 beta-[O-alpha-L-rhamnopyranosyl-(1 --> 3 )-O-beta-D-glucopyranuronosyloxy]machaerinate (1) and beta-D-glucopyranosyl 3 beta-[O-beta-D -galactopyranosyl-( 1 --> 2)-O-alpha-D-glucopyranuronosyl oxy]machaerinate (2) by NMR spectroscopy, including 2D-NMR experiments (mac haerinic acid = 3 beta,21 beta-dihydroxyolean-12-en-28-oic acid). The other saponins were identified as beta-D-glucopyranosyl 3B[O-alpha-L-rhamnopyran osyl-(l-3)-O-beta-D-glucopyranuronosyloxy]oleanolate (3), beta-D-glucopyran osyl 3 beta[O-alpha-D-galactopyranosyl(1 --> 2)-O-beta-D-glucopyranuronosyl oxy]oleanolate (4), and beta-D-glucopyranosyl 3 beta-[O-beta-D-glucopyranur onosyloxy]oleanolate (5) (oleanolic acid = 3 beta-hydroxyolean-12-en-28-oic acid).