MEDICINAL FOODSTUFFS .4. FENUGREEK SEED .1. STRUCTURES OF TRIGONEOSIDES IA, IB, IIA, IIB, IIIA, AND IIIB, NEW FUROSTANOL SAPONINS FROM THE SEEDS OF INDIAN TRIGONELLA-FOENUM-GRAECUM L

Six new furostanol saponins called trigoneosides Ia, Ib, IIa, IIb, III a, and IIIb were isolated from a medicinal foodstuff, fenugreek seed, the seed of Trigonella foenum-graecum L. (Legnminosae) originating fro m India, together with two known saponins, glycoside D and trigofoenos ide A. The structures of trigoneosides Ia, Ib, IIa, IIb, IIIa, and III b were determined on the basis of chemical and physicochemical evidenc e as 26-O-beta-D-glucopyranosyl-(25S)-5 alpha-furostane-2 alpha,3 beta ,22 xi,26-tetraol 3-O-[beta-D-xylopyranosyl (1-->6)]-beta-D-glucopyran oside, 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostane-2 alpha,3 be ta,22 xi,26-tetraol 3-O-[beta-D-xylopyranosyl (1-->6)]-beta-D-glucopyr anoside, 26-O-beta-D-glucopyranosyl-(25S)-5 beta-furostane-3 beta,22 x i,26-triol 3-O-[beta-D-xylopyranosyl (1-->6)]-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25R)-5 beta-furostane-3 beta,22 xi,26-trio l 3-O-[beta-D-xylopyranosyl (1-->6)]-beta-D-glucopyranoside, 26-O-beta -D-glucopyranosyl-(25S)-5 alpha-furostane-3 beta,22 xi,26-triol -L-rha mnopyranosyl(1-->2)]-beta-D-glucopyranoside, and 26-O-beta-D-glucopyra nosyl-(25R)-5 alpha-furostane-3 beta,22 xi,26-triol 3-O-[alpha-L-rhamn opyranosyl (1-->2)]-beta-D-glucopyranoside, respectively.