Chemical investigation of the seeds of Delphinium elatum L. resulted in the isolation of a new diterpenoid alkaloid delatisine whose structure (1) was established by 1H COSY, long range COSY, HETCOR, 2D nOe, fixed evolution HETCOR and selective INEPT nmr studies. The structure of the alkaloid was confirmed by an X-ray crystal structure determination. © 1991.