Certain Norditerpenoid Alkaloids and Their Cardiovascular Action

Thirteen new derivatives of norditerpenoid alkaloids, namely, 8-deacetyl-8-p-aminobenzoyldelphinine (1), 8-deacetyl-8-anthranoyldelphinine (2), 8-deacetyl-8-(4-hydroxy-3-methoxycinnamoyl)delphinine (3), 16-demethoxy-15,16-didehydro-8-p-anisoyl-14-benzoyldelphonine (4), 6-acetylheteratisine N-oxide (6), 3,8-diacetylfalconerine (7), 8-stearoylfalconerine (8), 8-linolenylfalconerine (9), 13-acetylpyrodelphinine (11), 13-acetyldelphinine N-oxide (13), N-deacetyl-8,9-diacetyllappaconitine (14), 8,9-(methylenedioxy)lappaconine (15), and 16-epipyroaconitine N-oxide (17), were prepared, and their structures were established by analysis of spectroscopic data (1D and 2D NMR, HRFABMS). The preliminary in vivo cardiovascular action (hypotensive, bradycardic, and ventricular arrhythmias) of these new compounds was tested in male Sprague−Dawley rats. The results are reported herein.