Pregnane- and furostane-type oligoglycosides from the seeds of Allium tuberosum.

Two furostane-type steroidal oligoglycosides (1, 2), together with a new pregnane-type oligoglycoside (3), were obtained from the seeds of Allium tuberosum ROTTLER. On the basis of spectroscopic analysis, the structures of three new oligoglycosides (1-3) were elucidated as 26-O-beta-D-glucopyranosyl-(25R)-3beta,22xi,26-trihydroxyl-5alpha-furostane 3-O-beta-chacotrioside, 26-O-beta-D-glucopyranosyl-(25S)-3beta,5beta,6alpha,22xi,26-pentahydroxyl-5beta-furostane 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranoside, and 3-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl 3beta,5beta,6alpha,16beta-tetrahydroxypregnane 16-(5-O-beta-D-glucopyranoyl-4(S)-methyl-5-hydroxypentanoic acid) ester, respectively.