The alkaloids of Corydalis pallida var. tenuis (Yatabe) and the structures of pallidine and kikemanine

Separation of the alkaloids from Corydalis pallida var. tenuis (Yatabe) afforded the known alkaloids, (–)-tetrahydropalmatine, protopine, capaurine, capaurimine, (+)-isoboldine, sinoacutine, and kikemanine (the last-named was identical with corydalmine), and the previously unknown alkaloids, pallidine and ‘alkaloid P.’ The morphinandienone alkaloid, pallidine, was also identified as (+)-isosalutaridine, the racemate of which has been synthesised previously.