Ascorbic Acid

Title: Ascorbic Acid
CAS Registry Number: 50-81-7
CAS Name: L-Ascorbic acid
Additional Names: vitamin C; 3-oxo-L-gulofuranolactone; L-threo-hex-2-enonic acid g-lactone; L-3-keto-threo-hexuronic acid lactone; L-xylo-ascorbic acid; antiscorbutic vitamin; cevitamic acid
Trademarks: Ascorbicap (Valeant); Ascorbin (Montavit); Ascorvit (Jenapharm); Cantan (Aventis); Cebion (Merck KGaA); Cecon (Abbott); Celaskon (Leciva); Celin (GSK); Cetebe (GSK); Cevalin (Lilly); Ce-Vi-Sol (BMS); Cevitan (Aventis); Cewin (Sanofi-Synthelabo); C-Vimin (AstraZeneca); Hicee (Takeda); Hybrin (Pfizer); Laroscorbine (Roche); Redoxon (Roche); Ribena (GSK); Vitacimin (Takeda); Vitacin (Towa Yakuhin); Vitascorbol (Aventis)
Molecular Formula: C6H8O6
Molecular Weight: 176.12
Percent Composition: C 40.92%, H 4.58%, O 54.51%
Literature References: Physiological antioxidant. Coenzyme for a number of hydroxylation reactions; required for collagen synthesis. Widely distributed in plants and animals. Most primates (including humans), guinea pigs, and some birds and fish cannot synthesize ascorbic acid. Inadequate intake results in deficiency syndromes such as scurvy. Dietary sources include citrus fruits, potatoes, peppers, broccoli, cabbage, and rose hips. First isolated from the adrenal cortex of ox and later from lemons and paprika (originally called hexuronic acid): A. Szent-Györgyi, Biochem. J. 22, 1387 (1928); W. N. Haworth, A. Szent-Györgyi, Nature 131, 24 (1933). Structure studies: R. W. Herbert et al., J. Chem. Soc. 1933, 1270. Synthesis: R. G. Ault et al., ibid. 1419; T. Reichstein et al., Helv. Chim. Acta 16, 561, 1019 (1933); 17, 311, 510 (1934). Review of discovery, structure and synthesis: E. L. Hirst, Fortschr. Chem. Org. Naturst. 2, 132-159 (1939). Crystal structure: J. Hvoself, Acta Chem. Scand. 18, 841 (1964). Review of syntheses: T. C. Crawford, S. A. Crawford, Adv. Carbohydr. Chem. 37, 79-155 (1980). HPLC determn in plasma: J. Lykkesfeldt et al., Anal. Biochem. 229, 329 (1995). Discussion of use in the treatment of the common cold: L. Pauling, Proc. Natl. Acad. Sci. USA 68, 2678 (1971); H. Hemilä, Scand. J. Infect. Dis. 26, 1 (1994). Clinical applications in immunology, lipid metabolism and cancer: Int. J. Vitam. Nutr. Res. 1982, Suppl. 23, 294 pp. Comprehensive description: I. A. Al-Meshal, M. M. A. Hassan, Anal. Profiles Drug Subs. 11, 45-78 (1982). Reviews: G. M. Jaffe in Kirk-Othmer Encyclopedia of Chemical Technology vol. 24 (John Wiley & Sons, New York, 3rd Ed., 1984) pp 8-40; "Vitamin C" in Vitamins, W. Friedrich, Ed. (Walter de Gruyter, Berlin, 1988) pp 929-1001. Review of pharmacology and clinical applications: M. Levine, N. Engl. J. Med. 314, 892-902 (1986); H. E. Sauberlich, Annu. Rev. Nutr. 14, 371-391 (1994).
Properties: Crystals (usually plates, sometimes needles, monoclinic system). Pleasant, sharp acidic taste. mp 190-192° (some dec). d 1.65. [a]D25 +20.5 to +21.5° (c = 1 in water); [a]D23 +48° (c = 1 in methanol). pH = 3 (5 mg/ml); pH = 2 (50 mg/ml); pK1 = 4.17; pK2 = 11.57. uv max at pH 2: 245 nm (E1%1cm 695); at pH 6.4: 265 nm (E1%1cm 940). Redox potential (first stage): E10 +0.166 V (pH 4). One gram dissolves in about 3 ml water, 30 ml alc, 50 ml abs alc, 100 ml glycerol, 20 ml propylene glycol. Soly in water: 80.0% at 100°; 40.0% at 45°. Insol in ether, chloroform, benzene, petr ether, oils, fats, fat solvents. Strong reducing agent. Stable to air when dry; aq solns are rapidly oxidized by air.
Melting point: mp 190-192° (some dec)
pKa: pK1 = 4.17; pK2 = 11.57
Optical Rotation: [a]D25 +20.5 to +21.5° (c = 1 in water); [a]D23 +48° (c = 1 in methanol)
Absorption maximum: uv max at pH 2: 245 nm (E1%1cm 695); at pH 6.4: 265 nm (E1%1cm 940)
Density: d 1.65
Derivative Type: Calcium hypophosphite
Additional Names: Asphocalcium
Trademarks: Calscorbat (Aerocid)
Molecular Formula: C6H9CaO8P
Molecular Weight: 280.18
Percent Composition: C 25.72%, H 3.24%, Ca 14.30%, O 45.68%, P 11.05%
Derivative Type: Calcium salt
CAS Registry Number: 5743-27-1
Additional Names: Calcium ascorbate
Molecular Formula: C12H14CaO12
Molecular Weight: 390.31
Percent Composition: C 36.93%, H 3.62%, Ca 10.27%, O 49.19%
Literature References: Prepn: Ruskin, Merrill, Science 105, 504 (1947).
Properties: Dihydrate, triclinic crystals, [a]D20 +95.6° (c = 2.4). Freely sol in water. Practically insol in methanol, ethanol.
Optical Rotation: [a]D20 +95.6° (c = 2.4)
Derivative Type: Sodium salt
CAS Registry Number: 134-03-2
Additional Names: Sodium ascorbate
Trademarks: Cenolate (Abbott); Xitix (Woelm)
Molecular Formula: C6H7NaO6
Molecular Weight: 198.11
Percent Composition: C 36.38%, H 3.56%, Na 11.60%, O 48.46%
Literature References: Prepn: Holland, US 2442005 (1948).
Properties: Minute crystals, dec 218°. [a]D20 +104.4°. Soly in water: 62 g/100 ml at 25°; 78 g/100 ml at 75°.
Optical Rotation: [a]D20 +104.4°
Use: As antimicrobial and antioxidant in foodstuffs.
Therap-Cat: Vitamin (antiscorbutic).
Therap-Cat-Vet: Vitamin (antiscorbutic).
Keywords: Vitamin/Vitamin Source; Vitamin C.
Ascorbigen Asiaticoside Asoprisnil Asoxime Chloride Asparagus

L-Ascorbic acid
L-Ascorbic acid.svg
CAS number 50-81-7 N
PubChem 5785
ChemSpider 10189562 N
EC number 200-066-2
KEGG D00018 YesY
ATC code A11GA01,G01AD03, S01XA15
Jmol-3D images Image 1
Image 2
Molecular formula C6H8O6
Molar mass 176.12 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)
Solubility in water 330 g/L
Solubility in ethanol 20 g/L
Solubility in glycerol 10 g/L
Solubility in propylene glycol 50 g/L
Solubility in other solvents insoluble in diethyl ether, chloroform, benzene, petroleum ether, oils, fats
Acidity (pKa) 4.10 (first), 11.6 (second)
Oxford University
NFPA 704
NFPA 704.svg
LD50 11.9 g/kg (oral, rat)[1]
 N (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Ascorbic acid is a naturally occurring organic compound with antioxidant properties. It is a white solid, but impure samples can appear yellowish. It dissolves well in water to give mildly acidic solutions. Ascorbic acid is one form ("vitamer") of vitamin C. It was originally called L-hexuronic acid, but, when it was found to have vitamin C activity in animals ("vitamin C" being defined as a vitamin activity, not then a specific substance), the suggestion was made to rename L-hexuronic acid. The new name for L-hexuronic acid is derived from a- (meaning "no") and scorbutus (scurvy), the disease caused by a deficiency of vitamin C. Because it is derived from glucose, many animals are able to produce it, but humans require it as part of their nutrition. Other vertebrates lacking the ability to produce ascorbic acid include other primates, guinea pigs, teleost fishes, bats, and some birds, all of which requiring it as a dietary micronutrient (that is, in vitamin form).[2]

There exists a D-ascorbic acid, which does not occur in nature. It may be synthesized artificially. It has identical antioxidant properties to L-ascorbic acid yet has far less vitamin C activity (although not quite zero).[3] This fact is taken as evidence that the antioxidant properties of ascorbic acid are only a small part of its effective vitamin activity. To be specific, L-ascorbate is known to participate in many specific enzyme reactions that require the correct epimer (L-ascorbate and not D-ascorbate).