Steroid alkaloid glycosides from Solanum robustum

Solamargine, solasonine, N-hydroxyrobustine and a new glycoalkaloid, N-hydroxysolamargine, has been isolated from the leaves of Solanum robustum, the structure of which has been elucidated as (25R)-3beta-{O-alpha-L-rhamnopyranosyl-(1-->2)-O-[alpha-L- rhamnopyranosyl- (1-->4)]-beta-D-glucopyranosyloxy}-22alphaN- spirosol-5-en-N-ol.