|Jmol-3D images||Image 1
|Molar mass||158.12 g mol−1|
|Appearance||colourless crystalline powder|
|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
|LD50||> 5000 mg/kg (oral, rat)|
(what is: / ?)|
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Allantoin is a chemical compound with formula C4H6N4O3. It is also called 5-ureidohydantoin or glyoxyldiureide. 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[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. 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. Allantoin is a major metabolic intermediate in many other organisms including plants and bacteria.