A novel furostanol saponin from Tribulus terrestris of Bulgarian origin

The phytochemical investigation of the aerial parts of Tribulus terrestris of Bulgarian origin has resulted in the isolation of the novel furostanol saponin 1, named tribol, together with the known spirostanol saponins 2 and 3 and sitosterol glucoside. The structure of tribol was determined as (25R)-furost-5(6)-ene-3beta,16,26-triol-3-O-alpha-rhamnopyranosyl-(1 --> 2)-[alpha-rhamnopyranosyl-(1 --> 4)]-beta-glucopyranoside (1) by spectral analysis, including extensive 1D and 2D-NMR experiments. (C) 2003 Elsevier B.V. All rights reserved.