Title: Allantoin
CAS Registry Number: 97-59-6
CAS Name: (2,5-Dioxo-4-imidazolidinyl)urea
Additional Names: 5-ureidohydantoin; glyoxyldiureide; cordianine
Molecular Formula: C4H6N4O3
Molecular Weight: 158.12
Percent Composition: C 30.38%, H 3.82%, N 35.43%, O 30.36%
Literature References: Product of purine metabolism. Prepd synthetically by the oxidation of uric acid with alkaline potassium permanganate: Org. Synth. coll. vol. II, 23 (1943). By heating urea with dichloroacetic acid: C. N. Zellner, J. R. Stevens, US 2158098 (1939 to Merck & Co.) Acetyl derivs: Biltz, Loewe, J. Prakt. Chem. 141, 291 (1934). Optically active forms have been obtained by extraction procedures.
Derivative Type: Racemic Form
Properties: Monoclinic plates or prisms from water, mp 238°. One gram dissolves in 190 ml water, 500 ml alcohol; more sol in hot water and hot alcohol. Almost insol in ether. pH of satd water soln: 5.5.
Melting point: mp 238°
Therap-Cat: Vulnerary.
Therap-Cat-Vet: Vulnerary; debriding agent.
Keywords: Topical Protectant; Vulnerary.
Allenolic Acid Allethrins Allidochlor Allobarbital Allocholesterol

Allantoin chemical structure.png
CAS number 97-59-6 YesY
PubChem 204
ChemSpider 199 YesY
UNII 344S277G0Z YesY
EC number 202-592-8
KEGG D00121 YesY
ChEBI CHEBI:15676 YesY
RTECS number YT1600000
Jmol-3D images Image 1
Image 2
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 (decomp.)
Boiling point 478 °C; 892 °F; 751 K
Solubility in water 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
MSDS Allantoin MSDS
NFPA 704
NFPA 704.svg
LD50 > 5000 mg/kg (oral, rat)
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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.[citation needed]

Named after the allantois (an amniote embryonic excretory organ in which it concentrates during development in most mammals except humans and higher apes[vague]), 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.