STIMULATION OF THE CONVERSION OF PENICILLIN N TO CEPHALOSPORIN BY ASCORBIC-ACID ALPHA-KETOGLUTARATE, AND FERROUS-IONS IN CELL-FREE-EXTRACTS OF STRAINS OF CEPHALOSPORIUM-ACREMONIUM

A cell-free system of the cephalosporin C fungus, Cephalosporiumacremonium, has been described which conversts penicillin N to a cephalosporin-like material which was biologically-active upon treatment with penicillinase with subsequent loss of activity when treated with cephalosporinase. We have confirmed this conversion independently in our laboratories and have shown that the activity was lost upon boiling, indicating the reaction is enzymatic in nature. Furthermore, we have shown that the production of the cephalosporin-like material was stimulated by the addition of ascorbic acid (3.8 μM) and ferrous ions (0.075 μM) to the reaction mixture, components which are co-factors in monooxygenase and dioxygenase reactions. © 1979.