Ji-glucosidase-treated saponin ~from Tribulus terrestris, and the identification of saponin ctiemotypes of South African T. terrestris

WILKINS, A.L., MILES, C.O., DE KOCK, W.T., ERASMUS, G.L., BASSON, A.T. & KELLERMAN, T.S. 1996. Photosensitivity in South Africa. IX. Structure elucidation of a ~-glucosidase-treated saponin from Tribulus terrestris and the identification of saponin chemotypes of South African T. terrestris. Onderstepoort Journal of Veterinary Research, 63:327-334 Saponin C, a ~-glucosidase-treated saponin isolated from ethanol-water extracts of a South African collection of Tribulus terrestris, was shown by oneand two-dimensional NMR spectroscopy to be ruscogenin 1 0-a-L-rhamnopyranosyi-(1-72)-~-D-6-0-acetylglucopyranoside. GC-MS analysis of the hydrolysed ethanol-water (4:1) extracts ofT. terrestris specimens from two of four sites, revealed high levels of ruscogenin and potentially lithogenic diosgenin saponins. Specimens from two other sites contained non-lithogenic saponins derived predominantly from tigogenin, neotigogenin, gitogenin and neegitogenin.