Chromatographic separation of the MeOH extract from the stems and rhizomes of Sinomemium acutum led to the isolation of nine alkaloids and a lignan. Their structures were determined to be dauriporphine (1), bianfugecine (2), dauriporphinoline (3), menisporphine (4), (-)-syringaresinol (5),
One new morphinane alkaloid, sinomenine N-oxide (1), and one new natural occurring morphinane alkaloid, N-demethylsinomenine (2), together with six known alkaloids, 7,8-didehydro-4-hydroxy-3,7-dimethoxymorphinan-6-ol (3), sinomenine (4), sinoacutine (5), N-norsinoacutine, acutumine, and acutumidine,