Abstract:
Geeldikkop was induced in a sheep by oral administration of crude saponins from Tribulus terrestris.
Centrifugation of the bile from this sheep gave a pale green sediment of crystalloid material which was
insoluble in common organic solvents, but soluble in acetic acid. Analysis of the crystalloid material by
¹H and ¹³C NMR, EDXA, TLC, LSIMS, and by acidic hydrolysis followed by TLC and GC-MS, revealed
it to be composed principally of a 6:1 mixture of the calcium salts of the β-D-glucuronides of the steroidal
sapogenins epismilagenin and episarsasapogenin. The administered saponin was found to contain
glycosides of the steroidal sapogenins diosgenin, yamogenin, epismilagenin, tigogenin, neotigogenin,
gitogenin and neogitogenin in the ratio 10:7:1:11:7:35:25. A metabolic pathway for the conversion of
diosgenin and yamogenin saponins to the biliary glucuronides is proposed.
