Preparative separation of naphthyltetrahydroisoquinoline alkaloids from Ancistrocladus korupensis by centrifugal partition chromatography.

Crude extracts of Ancistrocladus korupensis contain a complex mixture of naphthyltetrahydroisoquinoline alkaloids, including the human immunodeficiency virus-inhibitory dimeric alkaloids michellamines A and B and the antimalarial monomeric korupensamines A-D. The efficient separation of michellamines A and B from these extracts has been accomplished by centrifugal partition chromatography. The chromatographic conditions used on a multi-channel cartridge unit (Sanki LLN) have been successfully scaled up with a newly developed, stacked-disk type centrifugal partition chromatography unit (Sanki NMF) for separating larger amounts of alkaloid mixtures with similar resolution. A refined, three-step process (solvent-solvent partitioning, centrifugal partition chromatography and HPLC) has been developed and applied to the scaled-up production of michellamine B for preclinical drug development.