A new axially chiral naphthylisoquinoline alkaloid, ancistroheynine B (7), has been isolated from the leaves of the Indian liana Ancistrocladus heyneanus Wall., along with two known related alkaloids, ancistrocladidine (3) and ancistrotanzanine C (6), which are 7,30 -coupled, too. The structural elucidation was achieved by chemical, spectroscopic, and chiroptical methods. Biological activities of ancistroheynine B against the pathogens of malaria, leishmaniasis, Chagas disease, and African sleeping sickness were evaluated.