New triterpenoid saponins from Achyranthes aspera LINN

Abstract

Two new bisdesmosidic triterpenoid saponins were isolated, besides the three known saponins, from the MeOH ext. of the aerial parts of Achyranthes aspera LINN. (Amaranthaceae). Their structures were elucidated as β-D-glucopyranosyl 3β-[O-α-L-rhamnopyranosyl-(1→3)-O-β-D-glucopyranuronosyloxy]machaerinate (1) and β-D-glucopyranosyl 3β-[O-β-D-galactopyranosyl-(1→2)-O-α-D-glucopyranuronosyloxy]machaerinate (2) by NMR spectroscopy, including 2D-NMR expts. (machaerinic acid = 3β,21β-dihydroxyolean-12-en-28-oic acid). The other saponins were identified as β-D-glucopyranosyl 3β[O-α-L-rhamnopyranosyl-(1→3)-O-β-D-glucopyranuronosyloxy]oleanolate (3), β-D-glucopyranosyl 3-β-[O-β-D-galactopyranosyl-(1→2)-O-β-D-glucopyranuronosyloxy]oleanolate (4), and β-D-glucopyranosyl 3β-[O-β-D-glucopyranuronosyloxy]oleanolate (5) (oleanolic acid = 3β-hydroxyolean-12-en-28-oic acid). [on SciFinder(R)]