Two new furostanol saponins from Tribulus terrestris L.

Two new furostanol saponins, tribufurosides B (1) and C (2), were isolated from the fruits of Tribulus terrestris L. With the help of chemical and spectral analyses (IR, MS, 1D NMR and 2D NMR), the structures of two new furostanol saponins were established as 26-O-beta-D-glucopyranosyl-(25S)-5 alpha-furost-20(22)-en-2 alpha,3 beta,26-triol-3-O-beta-D-galactopyranosyl(1 -> 2)-beta-D-glucopyranosyl(1 -> 2)-beta-D-galactopyranoside (1) and (25S)-5 alpha-furost-20(22)-en-12-one-3 beta, 26-diol-26-O-beta-D-glucopyranoside (2).