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Chemistry of ascorbic acid

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**History of Ascorbic Acid:**
– James Lind demonstrated antiscorbutic properties of certain foods in the 18th century.
– Albert Szent-Györgyi isolated hexuronic acid in 1928-1932.
– Walter Norman Haworth deduced the correct structure of ascorbic acid in 1933.
– Haworth and Szent-Györgyi proposed renaming it ascorbic acid.
– Nobel Prizes in Chemistry and Physiology or Medicine awarded in 1937 for their work.

**Chemical Properties of Ascorbic Acid:**
– Ascorbic acid is a furan-based lactone of 2-ketogluconic acid.
– Forms salts like sodium ascorbate.
– Can react with organic acids to form esters like ascorbyl palmitate.
– Oxidizes to form dehydroascorbic acid, a mild reducing agent and antioxidant.

**Uses of Ascorbic Acid:**
– Mainly used as a food additive to combat oxidation.
– Commonly used as a dietary supplement.
– Used in various industries such as photography, preservatives, and fluorescence microscopy.
– Intravenous high-dose ascorbate used in chemotherapy and as a urinary acidifier.

**Synthesis of Ascorbic Acid:**
– Natural biosynthesis occurs in many plants and animals.
– Industrial synthesis from glucose via the Reichstein process.
– Reichstein process involves steps like catalytic hydrogenation of glucose to sorbitol and oxidation to sorbose.

**Production and Determination of Ascorbic Acid:**
– Ascorbic acid production is prominent in China using biotechnological processes.
– Determination methods include traditional titration, iodometry, and alternative oxidizing agents.
– Various references and resources are available for further information on ascorbic acid.

Ascorbic acid is an organic compound with formula C
, originally called hexuronic acid. It is a white solid, but impure samples can appear yellowish. It dissolves freely in water to give mildly acidic solutions. It is a mild reducing agent.

l-Ascorbic acid
IUPAC name
Other names
Vitamin C
3D model (JSmol)
EC Number
  • 200-066-2
E number E300 (antioxidants, ...)
  • InChI=1S/C6H8O6/c7-1-2(8)5-3(9)4(10)6(11)12-5/h2,5,7-10H,1H2/t2-,5+/m0/s1 ☒N
  • OC=1C(OC(=O)C=1O)[C@@H](O)CO
  • C([C@@H]([C@@H]1C(=C(C(=O)O1)O)O)O)O
Molar mass 176.124 g·mol−1
Appearance White or light yellow solid
Density 1.65 g/cm3
Melting point 190 to 192 °C (374 to 378 °F; 463 to 465 K) decomposes
330 g/L
Solubility Insoluble in diethyl ether, chloroform, benzene, petroleum ether, oils, fats
Solubility in ethanol 20 g/L
Solubility in glycerol 10 g/L
Solubility in propylene glycol 50 g/L
Acidity (pKa) 4.10 (first), 11.6 (second)
A11GA01 (WHO) G01AD03 (WHO), S01XA15 (WHO)
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
Lethal dose or concentration (LD, LC):
11.9 g/kg (oral, rat)
Safety data sheet (SDS) JT Baker
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Ascorbic acid exists as two enantiomers (mirror-image isomers), commonly denoted "l" (for "levo") and "d" (for "dextro"). The l isomer is the one most often encountered: it occurs naturally in many foods, and is one form ("vitamer") of vitamin C, an essential nutrient for humans and many animals. Deficiency of vitamin C causes scurvy, formerly a major disease of sailors in long sea voyages. It is used as a food additive and a dietary supplement for its antioxidant properties. The "d" form can be made via chemical synthesis, but has no significant biological role.

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