Studies on the Alkaloids of Papaveraceous Plants. XXIII. Alkaloids of Corydalis nokoensis HAYATA

A new alkaloid, named nokoensine, was isolated from Corydalis nokoensis HAYATA from Taiwan, together with protopine, dl-tetrahydropalmatine, dihydrosanguinarine, capaurine, corybulbine, sanguinarine, palmatine, captisine, and dehydrocorybulbine. The structure of nokoensine was determined as capaurine N-oxide from various spectral data and by the synthesis.