AN ENZYMATIC PROCESS FOR PREPARING BETA-LACTAMS

摘要

An enzymatic process under kinetical control for preparing b-lactams, by coupling the 7-amino group of a cephalosporin nucleus with the carboxylic function of an acetic acid derivative consisting of a residue with p-electrons, a short spacer and a carboxylic function activated as methyl- or ethylester. The process comprises using a penicillin amidase or a-amino acid esterase as free enzyme or in any suitable immobilised form; applying at least 100 mmol/l cephalosporin nucleus as long as it is soluble, otherwise 50 - 100 % of its maximum solubility is charged, applying the acetic acid activated as ester in a 1 - 3 fold molar ratio, and adjusting the pH to 6.0 - 8.0 and the temperature to 0 - 30 DEG C.