Two new steroidal glucosides from Tribulus terrestris L.

Two new furostanol saponins, tribufurosides D (1) and E (2), were isolated from the fruits of Tribulus terrestris L. With the help of chemical and spectral analyses (IR, MS, 1D, and 2D NMR), the structures of the two new furostanol saponins were established as 26-O-beta-d-glucopyranosyl-(25S)-5alpha-furost-12-one-2alpha,3beta,22alpha,26-tetraol-3-O-beta-d-glucopyranosyl-(1 --> 4)-beta-d-galactopyranoside (1) and 26-O-beta-d-glucopyranosyl-(25R)-5alpha-furost-12-one-2alpha,3beta,22alpha,26-tetraol-3-O-beta-d-glucopyranosyl-(1 --> 4)-beta-d-galactopyranoside (2).