83313-10-4Relevant articles and documents
Oxidation of Ascorbic Acid and Dehydroascorbic Acid by Superoxide Ion in Aprotic Media
Sawyer, Donald T.,Chiericato, Glaico,Tsuchiya, Tohru
, p. 6273 - 6278 (1982)
In dimethylformamide, superoxide ion (O2-) oxidizes ascorbic acid (H2A) to dehydroascorbic acid (A).The rate-limiting step is first order for each reactant and has a second-order rate constant (k) of 2.8 x 104 M-1 s-1; the overall stoichiometry is 3H2A molecules per 2O2- ions.Addition of O2- to dehydroascorbic acid (A) results in its rapid oxidation (k = 3.3 x 104 M-1 s-1), with an overall stoichiometry of 2O2- per A.The major products of the process are oxalate ion and the anion of threonic acid.On the basis of the reaction stoichiometries, kinetics, and products, self-consistent mechanisms are proposed for the oxidation of ascorbic acid and dehydroascorbic acid.