PENICILLIN AMIDASE-CATALYZED PREPARATIVE SYNTHESIS OF CEPHEM OXAZOLON-3-YL-ACETAMIDO)-DESACETOXYCEPHALOSPORANIC ACID USING A NONSPECIFIC POLYETHYLENEGLYCOL-MODIFIED ACYL DONOR

Penicillin amidase (EC 3.5.1.11) catalysed the synthesis of cephem oxa zolon-3-yl-acetamido)-desacetoxycephalosporanic acid by a kinetically controlled transfer of the non-specific 2-benzoxazolon-3-yl-acetyl moi ety from its polyethyleneglycol ester (m.w. 400, nine monomeric units) to the nucleophile 7-aminodesacetoxycephalosporanic acid. Penicillin amidase from E.Coli immobilised in polyacrylamide gel was used as bioc atalyst. A high degree of nucleophile conversion (98%) into the corres ponding cephem at biotechnologically relevant concentrations (50 mM) w as achieved.