Four alkaloids, strychnine, soladulcidine, solamargine and (3-O-beta-D-glucopyranosyl-(1 --> 2)beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranoside-(25xi)-solanidan-3beta,23beta-diol)(abbreviation, glycoalkaloid A) were isolated from Solanum lyratum Thunb. The structures were elucidated by NMR