Interconversion between Dehydro-L-Ascorbic Acid and L-Ascorbic Acid

Abstract

  L-Ascorbic acid (AA) plays an important role in biological systems as an electron donor. Erythorbic acid (EA) is the epimer of AA and has chemical characteristics very similar to those of AA. It is demonstrated in the present study by ¹H-NMR that dehydro-L-ascorbic acid (DAA) was reduced by EA under neutral conditions but not acidic, and that dehydroerythorbic acid (DEA) was also reduced by AA under the same conditions. These reactions also occurred at a low concentration close to the concentration of AA in such biological tissue as the liver. Furthermore, the interconversion of DAA and AA at neutral pH and low concentration was also confirmed by radioluminography. These results suggest the interconversion between DAA and AA in vivo.