Mbandakamines A and B, Unsymmetrically Coupled Dimeric Naphthylisoquinoline Alkaloids, from a Congolese Ancistrocladus Species

Mbandakamines A (1) and B (2), isolated from the leaves of an as yet unidentified Congolese Ancistrocladus species, are the first dimeric naphthylisoquinoline alkaloids with an unsymmetrically coupled central biaryl axis. Their novel 6′,1″-coupling type implies a hitherto unprecedented peri–peri coupling in one of the naphthalene parts, leading to the as yet highest steric hindrance at the central axis and a total of seven elements of chirality. Mbandakamine A exhibits good antimalarial activity.