New monomeric (korupensamine E, 6) and dimeric (michellamines D-F, 7-9) naphthylisoquinoline alkaloids have been isolated from exracts of the tropical liana Ancistrocladus korupensis. Structures were determined by spectroanalytical methods, and stereochemistry was defined through NOE correlations, chemical degradation, and CD spectroscopy. Michellamines D-F exhibited in vitro HIV-inhibitory activity comparable to michellamine B, and korupensamine E exhibited in vitro antimalarial activity comparable to korupensamines A-D.