Naveed_2014_Steroids_83C_45

Longipetalosides A-C (1-3); three new furostane steroidal saponins together with (25S)-5alpha-furastan-3beta,22,26-triol (4) and gitogenin (5) were isolated from the methanolic extract of the whole plant of Tribulus longipetalus. The structures of these compounds (1-5) were established by using 1D (1H, 13C) and 2D NMR (HMQC, HMBC, COSY, NOESY) spectroscopy, and mass spectrometry (ESIMS, HRESIMS), and in comparison with literature data reported for related compounds. Compounds 1-5 were evaluated for their inhibitory activities against enzymes alpha-glucosidase, lipoxygenase, acetylcholinesterase, and butyrylcholinesterase. Only the compounds 4 and 5 were found as the inhibitors of enzyme alpha-glucosidase with IC50 values of 33.5+/-0.22 and 37.2+/-0.18muM, respectively.