Megastigmane and 7,9'-dinorlignan glycosides from the tubers of Stephania kaweesakii

Two isomers of megastigmane glycosides, (6R, 9S)-blumenol C 9-O-gentibioside (2) and (6S, 9S)-blumenol C 9-O- gentiobioside (3), and a new 7,9'-dinorlignan glycoside, stepdonorlignoside (4) were isolated from the tubers Stephania kaweesakii. The structure determinations were considered based on the physical data and spectroscopic evidence. The absolute configurations of two megastigmanes were determined for the first time. Additionally, known compounds were isolated: (6R, 9S)-blumenol C 9-O-13-D-glucopyranoside, (+)-isolariciresinol 3a-O-13-D-glucopyranoside, salidroside, N-trans-caffeoyltyramine, (R)-isococlaurine, (R)-isococlaurine 4 & PRIME;-O-beta-glucopyr-anoside, (-)-oblongine, (+)-magnocurarine, fordianoside, and (-)-cyclanoline.