Penicillin amidase-catalysed preparative synthesis of cephem-7-(2-benzoxazolon-3-yl-acetamido)-desacetoxycephalosporanic acid using a non-specific polyethyleneglycol-modified acyl donor

Penicillin amidase (EC 3.5.1.11) catalysed the synthesis of cephem 7-(2-benzoxazolon-3-yl-acetamido)-desacetoxycephalosporanic acid by a kinetically controlled transfer of the non-specific 2-benzoxazolon-3-yl-acetyl moiety 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 biocatalyst. A high degree of nucleophile conversion (98%) into the corresponding cephem at biotechnologically relevant concentrations (50 mM) was achieved.