Separation of lactam derivatives of ergotoxine alkaloids, of which to were newly isolated from natural material, by high-performance liquid chromatography is described. The separation method utilizes LiChrosorb NH2 as a stationary phase eluted with diethyl ether-ethanol (96:4) as a mobile phase. Alkaloids are detected with a UV detector. The proposed names for the studied lactam derivatives are ergocristam, ergocristinam, erogocornam, ergocorninam, ergocryptam and ergocryptinam. © 1981.