The origin of desacetylcephalosporin C in cephalosporin C fermentation broths was investigated. Esterase activity was detected in cell-free extracts of Cephalosporium acremonium, but these extracts failed to deesterify cephalosporin C. When cephalosporin C was added to sterile and inoculated fermentation media, the antibiotic decayed at nearly identical rates. The formation of desacetylcephalosporin C during the fermentation was measured by quantitative chromatography and by the incorporation of valine-1-(14)C into the molecule. The rate constants obtained from the results of these experiments were equivalent to those for the decay of cephalosporin C in sterile and inoculated media. The data demonstrate that desacetylcephalosporin C is produced by nonenzymatic hydrolysis of cephalosporin C.
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http://dx.doi.org/10.1128/am.16.7.1011-1014.1968 | DOI Listing |
A sensitive and convenient method for the simultaneous determination of several of the compounds involved in the biosynthesis of penicillin and cephalosporin is described. The method involves derivatization with a chiral fluorogen (o-phthaldialdehyde with an optically active thiol N-acetyl-L-cysteine), followed by high-performance liquid chromatography on a reverse-phase column as described by Aswad (D. W.
View Article and Find Full Text PDFFour enzymes associated with the transformation of the peptide delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV) into the beta-lactam antibiotic desacetylcephalosporin C have been isolated from the prokaryotic organism Streptomyces clavuligerus and immobilized. Appropriate choice of the cofactors allows continuous and quantitative conversion of the peptide into either penicillins or cephalosporins at room temperature. The overall process includes four oxidations, two ring closures, and one epimerization.
View Article and Find Full Text PDFDuring fermentation of Acremonium chrysogenum, known cephalosporin-producing organism, there is formed, in addition, the main metabolite cephalosporin C. Its 3-desacetyl derivative, desacetylcephalosporin (DACS). The admixture of this derivative is not desirable.
View Article and Find Full Text PDFPol J Pharmacol Pharm
January 1980
The possibilities of 6-APA and 7-ADCA acylation by means of mixed anhydrides from ethyl chloroformate and cyclic carboxylic acids were investigated. The complexity of acylation course was observed, which depends upon kind of aminoderivative and structure of starting acid, respectively. In the case of mixed anhydrides formed from acid derivatives of which vicinal carbon atoms of ethylene bond built on into appropriate cyclic system were connected with methyl and carboxylic group (-C)CH3=C(COOH(-), it was found, that the main reaction products were: the suitable ureids and ethoxypenicillin or ethoxydesacetylcephalosporin.
View Article and Find Full Text PDFCell-free extracts of Acremonium chrysogenum and Streptomyces clavuligerus oxidize the 3-methyl group of desacetoxycephalosporin C to a 3-hydroxymethyl group. The enzyme responsible for this reaction in these organisms was purified 20- and 30-fold respectively by chromatography on DEAE-cellulose. The enzymes, which were assayed with [3-methyl-3H]desacetoxycephalosporin C as substrate, have the properties expected of 2-oxoglutarate-linked dioxygenases.
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