Furostane-Type Steroidal Saponins from the Roots of Chlorophytum borivilianum

Four new furostanol steroid saponins, borivilianosides A - D (1-4, resp.), corresponding to (3 beta,5 alpha,22R,25R)-26-(beta-D-glucopyranosyloxy)-22-hydroxyfurostan-3-yl O-beta-D-xylopyranosyl-(1 -> 3)-O-beta-D-glucopyranosyl-(1 -> 4)-O-[alpha-L-rhamnopyranosyl-(1 -> 2)]-beta-D-galactopyranoside (1), (3 beta,5 alpha,22R,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurostan-3-yl O-beta-D-xylopyranosyl-(1 -> 3)-O-beta-D-glucopyranosyl-(1 -> 4)-O-[alpha-L-rhamnopyranosyl-(1 -> 2)]-beta-D-galactopyranoside (2), (3 beta,5 alpha,22R,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurostan-3-yl O-beta-D-xylopyranosyl-(1 -> 3)-O-[beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranosyl-(1 -> 4)-beta-D-galactopyranoside (3), and (3 beta,5 alpha,25R)-26-beta-D-glucopyranosyloxy)furost-20(22)-en-3-yl O-beta-D-xylopyranosyl-(1 -> 3)-O-[beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranosyl-(1 -> 4)-beta-D-galactopyranoside (4), together with the known tribuluside A and (3 beta,5 alpha,22R,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurostan-3-yl O-beta-D-xylopyranosyl-(1 -> 2)-O-[beta-D-xylopyranosyl-(1 -> 3)]-O-beta-D-glucopyranosyl-(1 -> 4)-O-[alpha-L-rhamnopyranosyl-(1 -> 2)]-beta-D-galactopyranoside were isolated from the dried roots of Chlorophytum borivilianum SANT and FERN. Their structures were elucidated by 2D-NMR analyses (COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry.