title: Alkalimetric microassay of cephalosporins.
abstract: Alkalimetric pH-stat titrations of cephalosporin C, cephacetril and their deacetyl derivatives using an acetyl esterase and beta-lactamase are described. The esterase was used to assay highly purified samples of cephalosporin C and cephacetril, and also to prepare analytically defined solutions of the deacetyl cephalosporins. Lactamase-catalyzed hydrolysis of the parent compounds was then found to generate exactly 2 equivalents of acid per mole; that of the deacetyl derivatives exactly 1 equivalent.
mesh_terms: D000115:Acetylesterase / Q000378:metabolism; D001412:Bacillus subtilis / Q000201:enzymology; D001681:Biological Assay; D002511:Cephalosporins / Q000032:analysis*; D004754:Enterobacter / Q000201:enzymology; D006868:Hydrolysis; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D002511:Cephalosporins; D000115:Acetylesterase; D001618:beta-Lactamases