On the anaerobic and aerobic oxidation of xanthin and hypoxanthin by tissues and by milk

Abstract

Abstract Since the pioneer work of Burian, W. Jones and Schittenhelm, the conversion of the purin bases into uric acid by animal tissues has become a familiar case of biological oxidation. Apart from its physiological importance, the phenomenon must always be one of considerable chemical interest, because of the contrast between the remarkable ease with which it occurs under the influence of tissue catalysts, and the difficulty with which it is induced by ordinary laboratory oxidising agents. The literature of the subject seems throughout to emphasise the importance of free oxygen in the process. We have found, however, that certain animal tissues can induce the oxidation under conditions which are strictly anaerobic. This fact is significant in its bearing upon the nature of the catalysts concerned. Our inquiry began with the observation that in milk containing methylene blue, as a hydrogen acceptor, the bases are rapidly oxidised to uric acid in the absence of free oxygen.