7-氨基去乙酰氧基头孢烷酸

Biotechnol. Lett. 25(14) , 1195-8, (2003)

In the enzymatic synthesis of cefaclor, 3-chloro-7-d-(2-phenylglycinamide)-3-cephem-4-carboxylic acid, from phenylglycine methyl ester and 7-aminodesacetoxymethyl-3-chlorocephalosporanic acid, the in situ product could influence both the overall conversion an...

Enzyme Microb. Technol. 16(8) , 715-8, (1994)

Enzymatic production of cephalexin using immobilized penicillin G acylase was studied. The factors that affect the conversion of 7-amino-3-deacetoxycephalosporanic acid (7-ADCA) to cephalexin, such as pH; temperature; concentrations of 7-ADCA, D(-)-phenylglyc...

Biotechnol. Bioeng. 83(3) , 353-60, (2003)

The production kinetics of a transformed strain of Penicillium chrysogenum expressing the expandase gene from Streptomyces clavuligerus was investigated in chemostat cultivations. The recombinant strain produces adipoyl-7-aminodeacetoxycephalosporanic acid (a...

Nat. Biotechnol. 18(8) , 857-61, (2000)

Medically useful semisynthetic cephalosporins are made from 7-aminodeacetoxycephalosporanic acid (7-ADCA) or 7-aminocephalosporanic acid (7-ACA). Here we describe a new industrially amenable bioprocess for the production of the important intermediate 7-ADCA t...

Biotechnol. Bioeng. 83(3) , 361-8, (2003)

The growth stoichiometry of a Penicillium chrysogenum strain expressing the expandase gene from Streptomyces clavuligerus was determined in glucose-limited chemostat cultivations using a chemically defined medium. This strain produces adipoyl-7-aminodeacetoxy...

Biotechnol. Prog. 18(4) , 745-51, (2002)

Adipyl-7-ADCA is a new source for 7-aminodeacetoxycephalosporanic acid (7-ADCA), one of the substrates for antibiotics synthesis. In this paper, a novel process for enzymatic 7-ADCA production is presented. The process consists of a reactor, a crystallization...

Biotechnol. Bioeng. 85(3) , 323-9, (2004)

Advantages of performing penicillin acylase-catalyzed synthesis of new penicillins and cephalosporins by enzymatic acyl transfer to the beta-lactam antibiotic nuclei in the supersaturated solutions of substrates have been demonstrated. It has been shown that ...

Biochem. Biophys. Res. Commun. 312(3) , 755-60, (2003)

Residue Phe375 of cephalosporin acylase has been identified as one of the residues that is involved in substrate specificity. A complete mutational analysis was performed by substituting Phe375 with the 19 other amino acids and characterising all purified mut...

Cell. Mol. Life Sci. 58(5-6) , 835-43, (2001)

Deacetoxycephalosporin C synthase from Streptomyces clavuligerus catalyses the conversion of the five-membered penicillin ring to the unsaturated six-membered cephem ring of deacetoxycephalosporin C. The effects on enzyme activity of the penicillin substrate ...

Biochim. Biophys. Acta 1599(1-2) , 134-40, (2002)

Nucleophile reactivity of two most known nuclei of penicillins and cephalosporins, 6-aminopenicillanic (6-APA) and 7-aminodesacetoxycephalosporanic (7-ADCA) acids, was quantitatively characterized. In penicillin acylase (PA)-catalyzed acyl transfer reactions ...