KINETICS OF THE HYDROLYSIS OF CEPHALOSPORIN C

The decomposion rates of cephalosporin C in aqueous buffers and in fermentation broth at 25°C were determined by high pressure liquid chromatography and were found to obey the rate law -dC/dt=[Q.27 (H+) + 0.005 + 500 (OH-)]Cmole.l-1.h-1. In the acidity range from pH 3 to 7 the principal reaction is the slow attack of water on the nucleus. In alkaline and in strongly acidic solutions hydrolysis of the acetyl side chain is sufficiently fast relative to the base or acid catalyzed destruction of the nucleus to produce desacetyl cephalosporin C or its lactone in appreciable yields. In a typical fermentation non-enzymatic hydrolysis destroys about 15 % of the product.