Interaction of ascorbic acid with disulfides

Abstract

Electron spin resonance (EPR) spectra demonstrate the formation of a complex between the ascorbateion and disulfides such as oxidized glutathione, cystine, gamma globulin, bovine serum album in, 4–4′ dithiopyridine, and dithiobutyric acid. However, except in the case of 4–4′ dithiopyridine, ascorbic acid (AH2) is not capable o reducing the disulfide bond in these com pounds. These results can be explained in terms of the redox potential of ascorbic acid and its radical semidehydroascorbic (SDA). These compounds can reduce the S—S bond of 4–4′ dithiopyridine, the redox potential of which is E′o= – O. IV and, thus, more positive th an the ones determined for the ascorbic acid system. © 1983, Walter de Gruyter. All rights reserved.