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Allantoin

Allantoin
Skeletal formula of allantoin
Heap of white powder on a watch glass
Ball-and-stick model of the allantoin molecule
Names
IUPAC name
(2,5-Dioxo-4-imidazolidinyl) urea
Other names
Glyoxyldiureide
5-Ureidohydantoin
Identifiers
97-59-6 YesY
3D model (Jmol) Interactive image
Interactive image
ChEBI CHEBI:15676 YesY
ChEMBL ChEMBL593429 YesY
ChemSpider 199 YesY
ECHA InfoCard 100.002.358
EC Number 202-592-8
KEGG D00121 YesY
PubChem 204
RTECS number YT1600000
UNII 344S277G0Z YesY
Properties
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
Safety data sheet 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
Lethal dose or concentration (LD, LC):
LD50 (median dose)
 > 5000 mg/kg (oral, rat)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YesYN ?)
Infobox references

Allantoin is a chemical compound with formula C4H6N4O3. It is also called 5-ureidohydantoin or glyoxyldiureide. It is a diureide of glyoxylic acid. Allantoin is a major metabolic intermediate in most organisms including animals, plants and bacteria and is produced as a degradation product of purine nucleobases by urate oxidase (or uricase) from uric acid.

Allantoin was first isolated in 1800 by the Italian physician Michele Francesco Buniva (1761–1834) and the French chemist Louis Nicolas Vauquelin, who mistakenly believed it to be present in the amniotic fluid. In 1821, the French chemist Jean Louis Lassaigne found it in the fluid of the allantois; he called it "l'acide allantoique". In 1837, the German chemists Friedrich Wöhler and Justus Liebig synthesized it from uric acid and renamed it "allantoïn".

Named after the allantois (an amniote embryonic excretory organ in which it concentrates during development in most mammals except humans and other 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. In humans and other 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.


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