Tribulosin and β-sitosterol-D-glucoside, the anthelmintic principles of Tribulus terrestris

Successive extracts of Tribulus terrestris prepared using petroleum ether, chloroform, 50% methanol and water were tested for anthelmintic activity in-vitro using the nematode Caenorhabditis elegans. The activity could be detected only in 50% methanol extract which on further bioactivity guided fractionation and chromatographic separation yielded a spirostanol type saponin, tribulosin and β-sitosterol-D-glucoside. Both the compounds exhibited anthelmintic activity with ED 50 of 76.25 and 82.50 μg/ml respectively.