Delstaphidine (7) and neolinine (8), two new c₁₉-diterpenoid alkaloide, and a-oxodelphinine (9) have been isolated from the seeds of Delphinium staphisagria. The structures of these alkaloids were determined on the basis of spectral data, correlation with alkaloids of established structures, preparation of certain derivatives and by synthesis. a-Oxodelphinine has not been isolated from a natural source N-Deethyldelphisine (10) and N-deethyldelstaphidine (11), two new previously synthetic diterpenoid alkaloids, have been prepared by KMnO4 oxidation of delphisine. Oridative cyclization of delphisine with alkaline potassium ferricyanide gave delstaphinine (6)