Ascorbic acid

Ascorbic acid is an organic acid and antioxidant also 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 Medicine that year went to Albert Szent-Györgyi for his studies of the biological functions of ascorbic acid.

See the Vitamin C article for a discussion of social and historical aspects.

Chemistry

Formula: C₆H₈O₆
SMILES string: C1(O)=C(O)C(=O)OC1(C(O)CO)

Melting point: 190-192 °C.

The Molecular weight of L-ascorbic acid is 176.12.

Uses

Ascorbic acid is easily oxidized and so is used as a reductant in photographic developer solutions (among others) and as a preservative.

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 from glucose.

Ascorbic acid and its sodium, potassium, and calcium salts are commonly used as antioxidant food additives. These compounds are water soluble and thus cannot protect fats from oxidation: for this purpose, the fat-soluble esters 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.

Related article

For discussion of the historic and social role of the ascorbic acid molecule in human history see vitamin C.