(6S)-5-methyltetrahydrofolic acid or (6S)-5-methyltetrahydrofolate composition and preparation method and use thereof

The invention discloses a (6S)-5-methyltetrahydrofolic acid or (6S)-5-methyltetrahydrofolate composition and a preparation method and use thereof. The content of the (6S)-5-methyltetrahydrofolic acid or its salt is greater than or equal to 98.0% and the content of related impurity JK12A is less than or equal to 0.1%. 5-methyltetrahydropteroic acid cannot be found. The invention also provides a preparation method of the (6S)-5-methyltetrahydrofolic acid or (6S)-5-methyltetrahydrofolate composition, and a (6S)-5-methyltetrahydrofolic acid or (6S)-5-methyltetrahydrofolate solid solution and its preparation method. In the implement scheme, through ingenious use of the pharmaceutical acceptable reductant, potential harmful chemical products in (6S)-5-methyltetrahydrofolic acid or its salt products are transformed into the desired products so that safe use of the (6S)-5-methyltetrahydrofolic acid or (6S)-5-methyltetrahydrofolate products is realized.