Isolation and Structure Elucidation of the Major Degradation Products of Cefaclor Formed Under Aqueous Acidic Conditions
- 1 May 1997
- journal article
- Published by American Geophysical Union (AGU) in Journal of Pharmaceutical Sciences
- Vol. 86 (5) , 526-539
- https://doi.org/10.1021/js960427x
Abstract
The aqueous acidic degradation of the oral cephalosporin cefaclor was investigated. A number of degradation products were isolated and characterized. The degradation products can be loosely classified into three categories: thiazole derivatives, pyrazine derivatives, and simple hydrolysis or rearrangement products. Degradation pathways are proposed that involve (1) hydrolysis of the beta-lactam carbonyl with subsequent rearrangement, (2) ring contraction of the six-membered cephem nucleus to five-membered thiazole derivatives through an episulfonium ion intermediate, and (3) attack of the primary amine of the phenylglycyl side chain on the "masked aldehyde" at carbon-6 to form fluorescent substituted pyrazines.Keywords
This publication has 17 references indexed in Scilit:
- Isolation and Structure Elucidation of the Major Degradation Products of Cefaclor in the Solid StateJournal of Pharmaceutical Sciences, 1997
- The Degradation Mechanism of an Oral Cephalosporin: CefaclorHelvetica Chimica Acta, 1996
- Formation of fluorescent pyrazine derivatives via a novel degradation pathway of the carbacephalosporin loracarbefJournal of Pharmaceutical and Biomedical Analysis, 1995
- Isolation and Structure Elucidation of a Novel Product of the Acidic Degradation of CefaclorJournal of Pharmaceutical Sciences, 1993
- Long‐range two‐dimensional heteronuclear chemical shift correlationMagnetic Resonance in Chemistry, 1988
- Physicochemical properties of amphoteric .BETA.-lactam antibiotics. IV. First- and second-order degradations of cefaclor and cefatrizine in aqueous solution and kinetic interpretation of the intestinal absorption and degradation of the concentrated antibiotics.CHEMICAL & PHARMACEUTICAL BULLETIN, 1985
- 2-Hydroxy-3-aryl-6-methylpyrazines—fluorophores formed from the reaction of formaldehyde with cyclic enamine degradation products common to β-lactam antibiotics with aryl glycine side chainsJournal of Pharmacy and Pharmacology, 1981
- Applications of artificial intelligence for chemical inference. 37. GENOA: a computer program for structure elucidation utilizing overlapping and alternative substructuresThe Journal of Organic Chemistry, 1981
- Isolation and structural investigation of the fluorescent degradation products of ampicillin.CHEMICAL & PHARMACEUTICAL BULLETIN, 1981
- A "simple" approach to teaching hydrogen chemical shiftsJournal of Chemical Education, 1977