Steroidal glycosides from the flowers of Allium leucanthum

Furostanol and spirostanol glycosides 1 and 2 were isolated from the flowers of Allium leucanthum, a Caucasian endemic species that grows in Georgia. The structures were established on the base of chemical evidence and spectral analyses ( (1) H, (13) C NMR, (1) H- (1) H COSY, (1) H- (13) C COSY, HMBC, and HR-MS) data. Compound 1 (leucofuranoside A) was reported for the first time and was identified as 26-O-beta-Dglucopyranosyl-(25R)-5 alpha-furostane-3 beta,6 beta-diol-3-O-beta-D-glucopyranosyl-(1 -> 2)-O-beta-D-xylopyranosyl-(1 -> 3)-O-beta-D-glucopyranosyl-(1 -> 4)-beta-D-alactopyranoside. Compound 2 was identified as (25R)-5 alpha-spirostane-3 beta,6 beta-diol-3-O-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranosyl-(1 -> 4)-beta-D-galactopyranoside and described for the first time in the genus Allium.