Chemical reactions in cephalosporin allergy: high-pressure liquid chromatographic analysis of cephalosporin aminolysis kinetics.

Cephalosporin reaction with protein amino groups is fundamental to cephalosporin allergy. Cephalothin and cefazolin reaction kinetics with epsilon-aminocaproic acid, B-alanine, and glycine in aqueous solution were investigated. All reactions were conducted at 35 degrees and 0.5 ionic strength and were followed by ion-exchange high-pressure liquid chromatography. The aminolysis rate constants can be expressed as terms representing uncatlyzed or water-catalyzed amine reaction, self-assited nucleophilic reaction, and hydroxide-ion-catalayzed nucleophilic amine attack on the beta-lactam moiety. Cephalothin and cefazolin react with amines as readily as penicillin G. The UV spectra of several cephalothin-glycine reaction products were recorded, and their possible structures are discussed.