Method of preparing leurosine and vincaleukoblastine

Claim 1

THE METHOD OF PREPARING LEUROSINE AND VINCALEUKOBLASTINE IN SUBSTANTIALLY PURE FORM WHICH COMPRISES WETTING DRIED GROUND PLANTS OF THE SPECIES VINCA ROSEA LINN. WITH AQUEOUS 2 PERCENT TARTARIC ACID SOLUTION, EXTRACTING THE ACIDIFIED PLANT MATERIAL WITH BENZENE, SEPARATING THE BENZENE EXTRACT, CONTACTING THE BENZENE EXTRACT WITH ABOUT 2 PERCENT AQUEOUS TARTARIC ACID SOLUTION, SEPARATING THE TARTARIC ACID LAYER, EXTRACTING SAID TARTARIC ACID LAYER WITH A WATER-IMMISIBLE ORGANIC SOLVENT, AGAIN SEPARATING THE TARTARIC ACID LAYER, MAKING THE TARTARIC ACID LAYER BASIC WITH AMMONIUM HYDROXIDE, EXTRACTING THE THUS FROMED ALKALI-INSOLUBLE ALKALOIDAL FREE BASES INTO BENZENE, SEPARATING AND CONCENTRATING SAID BENZENE EXTRACT, AND THEN SUBJECTING SAID BENZENE EXTRACT TO A CHROMTOGRAPHIC SEPARATION PROCEDURE USING DEACTIVEATED ALUMINA AS THE ABSORBENT, IN WHICH CHROMATOGRAPHIC SEPARATION PROCEDURE UNDESIRED ALKALOIDS ARE ELUTED WITH BENZENE AND LEUROSINE AND VINCALEUKOBLASTINE ARE THEREAFTER ELUTED WITH CHLOROFORM-BENZENE SOVENT MIXTURES, CRYSTALLIZING LEUROSINE FROM ELUATE FRACTIONS GIVING A POSITIVE LEUROSINE TEST, AND CRYSTALLIZING VINCALEUKOBLASTINE IN THE FORM OF THE SULFATE SALT FROM FRACTIONS, INCLUDING MOTHER LIQUORS FROM LEUROSINE-CONTIANING FRACTIONS, SAID FRACTIONS AND MOTHER LIQUORS HAVING PREVIOUSLY GIVEN A POSITIVE TEST FOR VINCALEUKOBLASTINE.