title: [Enzymatic synthesis of cephradine].
abstract: Cephradine was synthesized by gamma-alumina-immobilized form of the penicillin G acylase of Bacillus megaterium with D-phenyglycine methylester hydrochloride (CH DGME.HCl) as acyl donor and 7-aminodeacetoxycephalosporanic acid (7-ADCA) as acyl acceptor. 0.1 g of 7-ADCA was dissolved by adding 2.5 ml of distilled water and about 0.25 ml of 2 mol/L NaOH in a 25 ml flask. To the solution, after 0.25 g of CHDGME.HCl was added, 0.1 mol/L phosphate-0.05 mol/L citric acid buffer, pH 7.5 was added to result in a volume of 5 ml with pH 7.5 Then 1 g(220 IU) of immobilized enzyme was added. The flask was shaken on a rotary shaker at 110 r/min and 25 degrees C for 5 h. The conversion rate of 7-ADCA was 81%. In an expanded experiment in 500 ml of reactive volume, 11.8 g of cephradine was obtained from 10 g of 7-ADCA. The conversion rate of 7-ADCA was 80% with about 87% yield of cephradine. Enzymatic synthesis was inhibited in varying degrees by phenylacetic acid, phenoxyacetic acid and cephalosporin G.
authors.affiliation: Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080.
authors.forename: F
authors.initials: F
authors.lastname: Cui
authors.forename: J
authors.initials: J
authors.lastname: Shi
authors.forename: X
authors.initials: X
authors.lastname: Bai
mesh_terms: D001410:Bacillus megaterium / Q000201:enzymology*; D002511:Cephalosporins / Q000737:chemistry; D002515:Cephradine / Q000138:chemical synthesis*; D004800:Enzymes, Immobilized / Q000378:metabolism; D010399:Penicillin Amidase / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D004800:Enzymes, Immobilized; C014320:7-aminodesacetoxycephalosporanic acid; D010399:Penicillin Amidase; D002515:Cephradine