Ancistrolikokine D, a 5,8′-coupled naphthylisoquinoline alkaloid, and related natural products from Ancistrocladus likoko

Abstract A new naphthylisoquinoline alkaloid, ancistrolikokine D, and the likewise 5,8′-coupled alkaloid ancistroealaine A, as well as two further, biosynthetically related, but nitrogen-free natural products, ancistronaphthoic acid B and cis -isoshinanolone, have been isolated from Ancistrocladus likoko J. Leonard (Ancistrocladaceae). The 5,8′-coupling of the new alkaloids and of the alkaloids isolated earlier hints at a close phylogenetic relationship of A. likoko to other Central African Ancistrocladus species. The compounds show moderate activities against Leishmania donovani , Trypanosoma cruzi , and Trypanosoma brucei rhodesiense .