Ascorbic acid is an organic acid with antioxidant properties. The L-enantiomer of ascorbic acid is commonly known as vitamin C. In 1937 the Nobel Prize for chemistry was awarded to Walter Haworth for his work in determining the structure of ascorbic acid, (It was shared with Paul Karrer, who received his award for work on vitamins), and the prize for Physiology or medicine that year went to Albert Szent_Györgyi for his studies of the biological functions of ascorbic acid.
Chemistry
Uses
Ascorbic acid is easily oxidized and so is used as a reductant in photographic developer solutions (among others) and as a preservative. Exposure to oxygen, metals, light and heat destroy ascorbic acid, so it must be stored in dark and cold and not in a metal containment.
The L-enantiomer of ascorbic acid is also known as vitamin C (the name "ascorbic" comes from its property of preventing and curing scurvy). Primates (including humans) and a few other species, such as the guinea pig, cannot synthesise vitamin C.
Ascorbic acid and its sodium, potassium, and calcium salts are commonly used as antioxidantfood additives. These compounds are water soluble and thus cannot protect fats from oxidation: for this purpose, the fat-solubleesters of ascorbic acid with long_chain fatty acids (ascorbyl palmitate or ascorbyl stearate) can be used as food antioxidants.
The relevant European food additive E numbers are: E300 ascorbic acid, E301 sodium ascorbate, E302 calcium ascorbate, E303 potassium ascorbate, E304 fatty acid esters of ascorbic acid (i) ascorbyl palmitate (ii) ascorbyl stearate.
See also
Vitamin C for a discussion of the medical properties of ascorbic acid as well as its historic and social role.
Measurements of ascorbate in urine, saliva, or serum indicate that if sufficient doses of ascorbate are not given when a patient is ill, the body level of vitamin C drops rapidly.
When ascorbate is destroyed in the process of destroying free radicals, the vitamin C stores, particularly in the cells directly involved in the disease process, are so depleted as to cause disorders of known housekeeping functions of vitamin C. It is certain that AIDS causes this depletion.
Ascorbate may or may not block these sensitivities significantly; however, ascorbate may decrease the intensity and duration of the reaction in such a way as to make clinical discovery of the offending substance easier.
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