A new diterpenoid alkaloid, named albovionitine, was isolated from Aconitum alboviolaceum. Its structure was elucidated by spectral analysis and was shown to be a seco-N-6 and N-20 hetisine-type diterpenoid alkaloid. Albovionitine is the first example of a diterpenoid alkaloid bearing a hydroxyl group at C-18 and a seco-N-20 functionality. Four known diterpenoid alkaloids were also isolated and identified as ajacine, avadharidine, lycoctonine and lycaconitine. © 1991.