Four new steroidal glycosides from Solanum torvum and their cytotoxic activities

Two novel C-22 steroidal lactone saponins, namely solanolactosides A, B ( 1 , 2 ) and two new spirostanol glycosides, namely torvosides M, N ( 3 , 4 ) were isolated from ethanol extract of aerial parts of Solanum torvum . Their structures were characterized as solanolide 6- O -[α- l -rhamnopyranosyl-(1 → 3)- O -β- d -quinovopyranoside] ( 1 ), solanolide 6- O -[β- d -xylopyranosyl-(1 → 3)- O -β- d -quinovopyranoside] ( 2 ), yamogenin 3- O -[β- d -glucopyranosyl-(1 → 6)- O -β- d -glucopyranoside] ( 3 ) and neochlorogenin 3- O -[β- d -glucopyranosyl-(1 → 6)- O -β- d -glucopyranoside] ( 4 ) on the basis of spectroscopic analysis. The cytotoxicities of the saponins ( 1 – 4 ) were evaluated in vitro against a panel of human cancer cell lines. Compounds 3 and 4 showed significant cytotoxic activity with the cell lines.