Steroidal glycosides from Allium albopilosum and A. ostrowskianum.

Chemical studies of the bulbs of Allium albopilosum and A. ostrowskianum have led to the isolation of two new steroidal saponins and four new cholestane glycosides together with several known compounds. The structures of the new compounds were established by the spectroscopic data, hydrolysis and chemical correlations as (25 R and S)-5 alpha-spirostane-2 alpha,3 beta,6 beta-triol 3-O-(O-beta-D-glucopyranosyl-(1-->2)-O-[3-O-acetyl-beta-D-xylopyranosyl- (1-->3)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside), (25R)-2-O-[(S)-3-hydroxy-3-methylglutaroyl]-5 alpha-spirostane-2 alpha, 3 beta, 6 beta-triol 3-O-(O-beta-D-glucopyranosyl-(1-->2)-O-[beta-D-xylopyranosyl-(1-->3)]-O- beta-D-glucopyranosyl-(1-->4)-beta-D-galactopyranoside), (22S)-cholest-5-ene-1 beta,3 beta,16 beta,22-tetraol 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside), 1 beta,3 beta,16 beta-trihydroxycholest-5-en-22-one 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside), 1 beta,3 beta,16 beta-trihydroxy-5 alpha-cholestan-22-one 1-O-alpha-L-rhamnopyranoside 16-O-(O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranoside) and (22S)-cholest-5-ene-1 beta,3 beta,16 beta,22-tetraol 16-O-(O-beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranoside).