SETT ATT ISOLERA ALKALOIDKOMPONENTER UR VINCA ROSEA L

Tumor inhibiting alkaloids are recovered from Vinca Rosea L. by a method which comprises extracting the dried leaves with a solvent selected from the group consisting of an alkanol having 1 to 5 carbon atoms, a mixture of an alkanol having 1 to 5 carbon atoms and a dilute, aqueous solution, benzene and benzene homologs; subsequently purifying the alkaloid extract obtained by a phase-change method between immiscible solvents, precipitating the main amount of dimeric alkaloids in form of their sulphuric acid addition salts, isolating leurosine, vincistine, vinblastine, desacetoxy-vinblastine, N-desmethyl-vinblastine and desacetyl-vinblastine from the salt mixture obtained, and then completing the separation and isolation of the remaining alkaloids by separation and isolation by adjusting the pH-value of the mother liquor, after precipitation and removal of the salt mixture, to 5.5 to 10, extracting the solution with a water-immiscible organic solvent and separating vindoline, catharantine, 3',4' -anhydrovinblastine and leurosine from the extract by chromatography, extracting vindoline in the pH-range of 2.5 to 3.5 and catharantine 3',4'-anhydrovinblastine and leurosine in the pH-range of 5 to 6 with benzene or a benzene homologue, from the mother liquor obtained when isolating the salt mixture, and separating a mixture of leurosine and 3',4'-anhydrovinblastine by crystallization, epoxidizing this mixture with an oxygen source, or separating the mixture into its components by chromatography, and subsequently epoxidizing the 3',4'-anhydrovinblastine component to leurosine, and isolating catharantine remaining from the mother liquor obtained when separating the crystalline mixture, or separating the extract containing catharantine, 3',4'-anhydrovinblastine and leurosine into its components by chromatography.