| 摘要 |
<p>Process for the preparation of a chiral amino acid enriched in the D-enantiomer, in which a mixture of the enantiomers of the corresponding N-carbamoylamino acid is brought into contact with a D-carbamoylase with ammonia being liberated, the ammonia being removed with the aid of a bivalent metal salt of a phospahte, a monohydrogen phosphate or a dihydrogen phosphate ion. In one embodiment the enzymatic decarbamoylation is carried out in the presence of a bivalent metal salt of a phosphate ion, a monohydrogen phosphate ion or a dihydrogen phosphate ion. In another embodiment the reaction mixture is brought into contact via an external loop, after separation of the solid present, with the bivalent metal salt of a phosphate ion, monohydrogen phosphate ion or dihydrogen phosphate ion. The chiral amino acid enriched in the D-enantiomer can also be obtained by enzymatically converting the corresponding hydantoin with the aid of a hydantoinase into the corresponding N-carbamoylamino acid, which is subsequently converted according to the invention into the amino acid enriched in the D-enantiomer.</p> |
