The structure and the stereochemistry of afrocurarine (a new unsymmetrical bisindole alkaloid) previously isolated from S. USAMBARENSIS Gilg. are established especially from (1)H-NMR spectroscopic data. The separation of quaternary alkaloids has always been very tedious. Ion-pair reversed-phase column chromatography applied to the purification of afrocurarine is proved very useful and seems to be a suitable technique in quaternary alkaloid research.