Twenty alkaloids have been isolated from the leaves, fruit and stem-bark of Alstonia sphaerocapitata from New Caledonia. They were vincamedine, 10-methoxyvincamedine, Z-isositsirikine, akuammicine, quaternoline, 11-methoxyakuammicine, tubotaiwine, 10-methoxyvincamedine N(4)-oxide, cabucraline, cathafoline, caberoline, vincoridine, quebrachidine, quaternoxine, nor C-fluorocurarine, desoxycabufiline, nordesoxycabufiline and three alkaloids of unknown structure. © 1984.