Ascorbic acid

This article deals with the chemical aspects of ascorbic acid, for information on its nutritional value see Vitamin C

Ascorbic acid or vitamin C is a colorless, odorless, solid, water-soluble crystal with an acid taste. It is an organic acid, with antioxidant properties.

In humans, primates and guinea pigs, among others, vitamin C (L-enantiomer of ascorbic acid) is not synthesized, so it must be ingested through food. This is due to the absence of the enzyme L-gluconolactone oxidase, which is involved in the uric acid pathway.

Etymology

The L (levorotatory) enantiomer of this acid is commonly known as vitamin C. The name "ascorbic" It comes from the prefix a- ("sin") and from the Latin scorbuticus ("scurvy"), it comes from its property of preventing and cure scurvy. Vitamin C, S enantiomer of ascorbic or antiscorbutic acid, is an essential nutrient for humans, primates, guinea pigs and some bats, who lack the mechanism for its synthesis. The rest of the mammals synthesize it naturally in the liver.

Chemistry

• Formula: C
  6H
  8O
  6
• Empirical formula: C
  3H
  4O
  3
• SMILES Format: C1(O)=C (O) C(=O)OC1(C (O) CO)
• Fusion temperature: 189-192 °C / 462 K - 465 K

Uses

Ascorbic acid fights infections, heals wounds and helps heal damaged tissue.

History

Since the XVI century, the Spanish had already realized that citrus fruits prevented the appearance of scurvy among the sailors. At first, it was assumed that the acidic properties were responsible for this benefit; however, it soon became apparent that other dietary acids, such as vinegar, had no such benefits. In 1907, two Norwegian physicians reported an essential compound in food to prevent disease, other than the one that prevented beriberi. These physicians were investigating dietary deficiency diseases using the new animal model of guinea pigs, susceptible to scurvy. The newly discovered dietary factor was eventually named vitamin C.

Between 1928 and 1932, the Hungarian research team led by Albert Szent-Györgyi, and that of American researcher Charles Glen King, identified the antiscorbutic factor as a particular and simple chemical substance. At the Mayo Clinic, Szent-Györgyi had chemically isolated hexuronic acid from the adrenal glands of animals; he suspected it was the antiscorbutic factor but could not prove it without a bioassay. Such a trial was finally carried out at the University of Pittsburgh, using guinea pigs in the lab of King, who had worked on the problem for years. In late 1931, King's laboratory obtained renal hexuronic acid indirectly from Szent-Györgyi and, using his animal model, demonstrated in early 1932 that it was vitamin C.

This was the last of the compounds of animal origin; but later that same year, Szent-Györgyi's group discovered that paprika pepper, a common spice in the Hungarian diet, was a rich source of hexuronic acid. He sent some of the now most available chemicals to Walter Norman Haworth, a British sugar chemist. In 1933, working with then Assistant Director of Research (and later Sir) Edmund Hirst and his research teams, Haworth deduced the correct structure and isomeric-optic nature of vitamin C, and in 1934 reported the first synthesis of the vitamin. In honor of the compound's antiscorbutic properties, Haworth and Szent-Györgyi then proposed the new compound for the compound. name "a-scorbic acid" (a-scorbic acid). They eventually named it L-ascorbic acid themselves when its structure was proven by synthesis.

In 1937, the Nobel Prize in Chemistry was awarded to Haworth for his work determining the structure of ascorbic acid (shared with Paul Karrer, who received his prize for work on vitamins), and the prize for Physiology or Medicine of that same year went to Szent-Györgyi for his studies on the biological functions of L-ascorbic acid. American physician Fred R. Klenner promoted vitamin C as a cure for many diseases in the 1950s by greatly increasing doses up to tens of grams of vitamin C per day by injection. Since 1967, another Nobel Prize winner, Linus Pauling, has recommended high doses of ascorbic acid (he himself took 18 grams a day) as a preventative against colds and cancer. Klenner's results have been controversial to date, as his research does not meet modern methodological standards.