Dehydroascorbic acid GLUT1 transporters, and then converted back to ascorbate. Dehydroascorbic acid has been used as a vitamin C dietary supplement. As a cosmetic ingredient, dehydroascorbic acid is used to enhance the appearance of the skin. It may be used in a process for permanent waving of hair and in a process for sunless tanning of skin. In a cell culture growth medium, dehydroascorbic acid has been used to assure the uptake of vitamin C into cell types that do not contain ascorbic acid transporters. As a pharmaceutical agent, some research has suggested that administration of dehydroascorbic acid may confer protection from
Chemistry of ascorbic acid catalytically hydrogenated to sorbitol, which is then oxidized by the microorganism "Acetobacter suboxydans" to sorbose. Only one of the six hydroxy groups is oxidized by this enzymatic reaction. From this point, two routes are available. Treatment of the product with acetone in the presence of an acid catalyst converts four of the remaining hydroxyl groups to acetals. The unprotected hydroxyl group is oxidized to the carboxylic acid by reaction with the catalytic oxidant TEMPO (regenerated by sodium hypochlorite — bleaching solution). Historically, industrial preparation via the Reichstein process used potassium permanganate as the bleaching solution. Acid-catalyzed hydrolysis of this product