Patent ID: RE45128

Claim:
A purified compound of the following formula Cephalotaxine, 4-methyl (2′R)-2-hydroxy-2-(4-hydroxy-4-methylpentyl) butanedioate (ester) : wherein n=2 or n=3, having a total content of impurities of lower than 1% , and/or and having a total content of impurities wherein the major impurity is lower than 0.9% , and the chromatographic assay of the purified compound cephalotaxine, 4-methyl (2′R)-2-hydroxy-2-(4-hydroxy-4-methylpentyl) butanedioate (ester) exhibits a content of the purified compound cephalotaxine, 4-methyl (2′R)-2-hydroxy-2-(4-hydroxy-4-methylpentyl) butanedioate (ester) of higher than 97.5% , and/or a salt thereof .