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 anti-plasmodial activity in vitro towards Plasmodium falciparum erythrocytic forms, as compared to its less methylated precursors.