A
general public availability
The pharmacophore of vitamin C is the ascorbate ion. In living organisms, ascorbate is an anti-oxidant, since it protects the body against oxidative stress,[5] and is a cofactor in several vital enzymatic reactions.[6]
Vitamin C is purely the L-enantiomer of ascorbate; the opposite D-enantiomer has no physiological significance. Both forms are mirror images of the same molecular structure. When L-ascorbate, which is a strong reducing agent, carries out its reducing function, it is converted to its oxidized form, L-dehydroascorbate.[6] L-dehydroascorbate can then be reduced back to the active L-ascorbate form in the body by enzymes and glutathione.[9] During this process semidehydroascorbic acid radical is formed. Ascorbate free radical reacts poorly with oxygen, and thus, will not create a superoxide. Instead two semidehydroascorbate radicals will react and form one ascorbate and one dehydroascorbate. With the help of glutathione, dehydroxyascorbate is converted back to ascorbate.[10] The presence of glutathione is crucial since it spares ascorbate and improves antioxidant capacity of blood.[11] Without it dehydroxyascorbate could not convert back to ascorbate.
