AJADININE - A NEW NORDITERPENOID ALKALOID FROM THE SEEDS OF DELPHINIUM-AJACIS - THE COMPLETE NMR ASSIGNMENTS FOR SOME LYCOCTONINE-TYPE ALKALOIDS

A new nordirerpenoid alkaloid designated as ajadinine [1] has been iso lated from the seeds of Delphinium ajacis. Its structure [1] was estab lished from physical and spectroscopic data. The known alkaloids desol ine, delcosine, and gigactonine have also been obtained from this same source. Complete and unambiguous nmr assignments for the lycoctonine- type norditerpenoid alkaloids 14-deacetylajadine [2], ajacine [3], del cosine [4], and ambiguine [5] are also presented in this work. Assignm ents for the aromatic protons of the C-18 N-acetyl anthranilic acid es ter group were made by selective INEPT nmr experiments.