THE INHIBITORY MECHANISMS OF GLUCOSE AND CARBON-DIOXIDE ON THE BIOSYNTHESES OF PENICILLINS AND CEPHALOSPORINS

The inhibitory mechanism of glucose and CO2 on the biosyntheses of pen icillins and cephalosporins is discussed in the present paper. 6-amino penicillanic acid (6-APA) is considered to be an intermediate product, and the reaction between 6-APA and glucose may play an important role in the yield and rate of biosyntheses of beta-lactam antibiotics. Acc ording to this hypothesis the experimental phenomena taking place in b iosynthesis of penicillin and cephalosporin, such as the inhibition by glucose and carbon dioxide and the reduction of the yield, can be sat isfactorily explained. The stability of 6-aminopenicillanic acid (6-AP A) in bicarbonate solution, the reaction of 6-APA with sugars, the det ermination of the concentration of the 6-APA-sugar compound and the ef fect of these reactions on the biosynthesis of penicillin G are invest igated to present evidences for this hypothesis.