From the ethanolic extract of Delphinium barbeyi Huth, a novel C19-Diterpenoid alkaloid barbeline (4) has been isolated and its structure determined by spectroscopic data and an X-ray crystal diffraction study. Barbeline is the only example of an alkaloid containing a C(19)=N- azomethine group among the 230 naturally occurring C19-diterpenoid alkaloids. Two other new alkaloids, 6-acetyldelpheline and 6-deoxydelpheline, as well as the known alkaloids browniine, delphatine and glaucenine have also been isolated from this plant. © 1988.