Dehydroascorbic acid

Structure and physiology

Top: ascorbic acid (reduced form of vitamin C) Bottom: dehydroascorbic acid (nominal oxidized form of vitamin C)

Although sodium-dependent transporters for vitamin C exists, it is present mainly in specialized cells whereas the glucose transporters, most notably GLUT1, transport DHA in most cells, where recycling back to ascorbic acid generates the necessary enzyme cofactor and intracellular antioxidant, (see Transport to mitochondria).

The structure shown here for DHA is the commonly shown textbook structure. This 1,2,3-tricarbonyl is too electrophilic to survive more than a few milliseconds in aqueous solution, however. The actual structure shown by spectroscopic studies is the result of rapid hemiketal formation between the 6-OH and the 3-carbonyl groups. Hydration of the 2-carbonyl is also observed. |doi-access=free

Transport to mitochondria

Vitamin C accumulates in mitochondria, where most of the free radicals are produced, by entering as DHA through the glucose transporter GLUT10. Ascorbic acid protects the mitochondrial genome and membrane. |doi-access=free

Transport to the brain

Vitamin C does not pass from the bloodstream into the brain, although the brain is one of the organs that have the greatest concentration of vitamin C. Instead, DHA is transported through the blood–brain barrier via GLUT1 transporters, and then reduced back to ascorbic acid. |doi-access=free

Use

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.{{Citation | access-date = 2012-07-31

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 neuronal injury following an ischemic stroke. The literature contains many reports on the antiviral effects of vitamin C, and one study suggests dehydroascorbic acid has stronger antiviral effects and a different mechanism of action than ascorbic acid.

References

References

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