N,N-dimethyldioncophyllinium A iodide: synthesis, stereoanalysis, and antimalarial activity of the first N-quaternary naphthylisoquinolinium salt.

The first synthesis of an N-quaternary salt of a naphthylisoquinoline alkaloid, N,N-dimethyldioncophyllinium A iodide, is described. For this potential natural product, a degradative procedure for the unambiguous stereoanalysis of the stereogenic centers has been elaborated. It shows enhanced antiplasmodial activity in vitro towards Plasmodium falciparum erythrocytic forms, as compared to its less methylated precursors.