Diterpenoid alkaloids from Delphinium davisii

Three new hetisane-type diterpenoid alkaloids, davisinol, 18-benzoyldavisinol, and Davisin have been isolated from Delphinium davisii Munz. and their structures established by detailed spectroscopic studies. Accurate 1H- and 13C-NMR assignments have been made for kobusine, a related hetisane-type alkaloid, and karakoline, a norditerpenoid alkaloid. The known norditerpenoid alkaloids 14-acetylperegrine, 6-deacetylperegrine, and karakoline and the diterpenoid alkaloids hetisine and hetisinone were also isolated