Synthesis and cytotoxicities of icogenin analogues with disaccharide residues

For further structure-activity relationships (SAR) research of furostan saponin, two icogenin analogues: (25R)-22-O-methyl-furost-5-en-3beta,26-diol-3-O-alpha-l-rhamnopyranosyl-(1-->2)-beta-d-glucopyranoside 1 and (25R)-22-O-methyl-furost-5-en-3beta,26-diol-3-O-alpha-l-rhamnopyranosyl-(1-->2)-alpha-d-glucopyranoside 2, with valuable disaccharide moieties, were synthesized from diosgenin through eight steps. Both of the analogues behaved the similar cytotoxic activities with icogenin, towards nine types of human tumor cells herein.