Two new furostanol glycosides from the fruits of Tribulus terrestris

Two new furostanol glycosides, named terrestrinones A1/A2 (1a/1b), were isolated from the fruits of Tribulus terrestris L. together with four known compounds, and their structures were determined by spectroscopic methods, including 2D NMR experiments. All of the isolates (1-5) were evaluated for their potential to inhibit the LPS-induced production of nitric oxide in murine macrophage RAW264.7 cells. Of these, compounds 2 and 3 inhibited nitric oxide production with IC50 values of 7.1 and 46.6 μM.