The alkaloids of Corydalis meifolia.

Six tetrahydroprotoberberines, (+)-sinactine, apocavidine, stylopine, (+)-cavidine, cheilanthifoline, and dehydrocavidine; two spirobenzylisoquinolines, yenhusomine and yenhusomidine; one phthalideisoquinoline, corlumine; one benzophenanthridine, dihydrosanguinarine and protopine, have been isolated from the leaves and stems of Corydalis meifolia Wall. Of these alkaloids, dehydrocavidine was a new base. The remaining alkaloids, although known, were isolated for the first time for this plant. (+)-Cavidine, protopine, corlumine, yenhusomine, and dehydrocavidine exhibited spasmolytic activity.