Allantoin

Allantoin
Names
IUPAC name
(2,5-Dioxo-4-imidazolidinyl) urea
Other names
Glyoxyldiureide
5-Ureidohydantoin
Identifiers
97-59-6 Yes
ChEBI CHEBI:15676 Yes
ChEMBL ChEMBL593429 Yes
ChemSpider 199 Yes
EC number 202-592-8
Jmol-3D images Image
Image
KEGG D00121 Yes
PubChem 204
RTECS number YT1600000
UNII 344S277G0Z Yes
Properties
Molecular formula
 C4H6N4O3
Molar mass 158.12 g·mol−1
Appearance colourless crystalline powder
Odor odorless
Density 1.45 g/cm3
Melting point 230 °C (446 °F; 503 K) (decomposes)
Boiling point 478 °C (892 °F; 751 K)
0.57 g/100 mL (25 °C)
4.0 g/100 mL (75 °C)
Solubility soluble in alcohol, pyridine, NaOH
insoluble in ethyl ether
log P -3.14
Acidity (pKa) 8.48
Hazards
MSDS Allantoin MSDS
NFPA 704
Flammability code 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g., canola oil Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
1
2
0
> 5000 mg/kg (oral, rat)
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 Yes verify (what is: Yes/?)
Infobox references

Allantoin is a chemical compound with formula C4H6N4O3. It is also called 5-ureidohydantoin or glyoxyldiureide.[1][2] It is a diureide of glyoxylic acid.

Named after the allantois (an amniote embryonic excretory organ in which it concentrates during development in most mammals except humans and higher apes), it is a product of oxidation of uric acid by purine catabolism. After birth, it is the predominant means by which nitrogenous waste is excreted in the urine of these animals.[3] In humans and higher apes, the metabolic pathway for conversion of uric acid to allantoin is not present, so the former is excreted. Recombinant rasburicase is sometimes used as a drug to catalyze this metabolic conversion in patients. In fish, allantoin is broken down further (into ammonia) before excretion.[4] Allantoin is a major metabolic intermediate in many other organisms including plants and bacteria.

Applications

Allantoin is present in botanical extracts of the comfrey plant and in the urine of most mammals. Chemically synthesized bulk allantoin, which is chemically equivalent to natural allantoin, is safe, non-toxic, compatible with cosmetic raw materials and meets CTFA and JSCI requirements. Over 10,000 patents reference allantoin.[5] Manufacturers cite several beneficial effects for allantoin as an active ingredient in over-the-counter cosmetics, including: a moisturizing and keratolytic effect, increasing the water content of the extracellular matrix and enhancing the desquamation of upper layers of dead skin cells, increasing the smoothness of the skin; promoting cell proliferation and wound healing; and a soothing, anti-irritant, and skin protectant effect by forming complexes with irritant and sensitizing agents. A study published in 2009 reported the treatment of pruritus in mild-to-moderate atopic dermatitis with a topical non-steroidal agent containing allantoin.[6]

It is frequently present in toothpaste, mouthwash, and other oral hygiene products, in shampoos, lipsticks, anti-acne products, sun care products, and clarifying lotions, various cosmetic lotions and creams, and other cosmetic and pharmaceutical products.[7]

Since uric acid is the end product of the purine metabolism in humans, only non-enzymatic processes with reactive oxygen species will give rise to allantoin, which is thus a suitable biomarker to measure oxidative stress in chronic illnesses and senescence.[8][9]

See also

References

  1. ↑ http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=204
  2. ↑ http://www.chemblink.com/products/97-59-6.htm
  3. ↑ Young E. G., Wentworth H. P., Hawkins W. W. (1944). "The absorption and excretion of allantoin in mammals". J. Pharmacol. Experi. Therapeutics 81 (1): 1–9.
  4. ↑ Fujiwara, S; Noguchi T (1995). "Degradation of purines: only ureidoglycollate lyase out of four allantoin-degrading enzymes is present in mammals". The Biochemical Journal 312 (Pt 1): 315–8. PMC 1136261. PMID 7492331.
  5. ↑ Patent Lens search
  6. ↑ Veraldi, S; De Micheli, P; Schianchi, R; Lunardon, L (2009). "Treatment of pruritus in mild-to-moderate atopic dermatitis with a topical non-steroidal agent". Journal of drugs in dermatology : JDD 8 (6): 537–9. PMID 19537379.
  7. ↑ Thornfeldt, C (2005). "Cosmeceuticals containing herbs: fact, fiction, and future". Dermatologic Surgery 31 (7 Pt 2): 873–80. doi:10.1111/j.1524-4725.2005.31734. PMID 16029681.
  8. ↑ Kand'ár R, Záková P. (2008). "Allantoin as a marker of oxidative stress in human erythrocytes". Clinical chemistry and laboratory medicine : CCLM / FESCC 46 (9): 1270–4. doi:10.1515/CCLM.2008.244. PMID 18636793.
  9. ↑ Zitnanová I, Korytár P, Aruoma OI, Sustrová M, Garaiová I, Muchová J, Kalnovicová T, Pueschel S, Duracková Z (2004). "Uric acid and allantoin levels in Down syndrome: Antioxidant and oxidative stress mechanisms?". Clinica chimica acta; international journal of clinical chemistry 341 (1–2): 139–46. doi:10.1016/j.cccn.2003.11.020. PMID 14967170.

External links