Alloxan
From Wikipedia, the free encyclopedia
| Alloxan[1] | |
|---|---|
 |
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| IUPAC name | 1,3-Diazinane-2,4,5,6-tetrone |
| Other names | Mesoxalylurea 5-Oxobarbituric acid |
| Identifiers | |
| CAS number | 50-71-5 2244-11-3 (Monohydrate) |
| PubChem | |
| MeSH | |
| SMILES | C1(=O)C(=O)NC(=O)NC1=O |
| Properties | |
| Molecular formula | C4H2N2O4 |
| Molar mass | 142.07 g/mol |
| Melting point |
256 °C (decomposition) |
| Solubility in water | Freely soluble |
| Hazards | |
| MSDS | MSDS |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Alloxan or mesoxalylurea is an organic compound based on a pyrimidine heterocyclic skeleton.
This compound has a high affinity for water and therefore exists as the monohydrate.
Contents |
[edit] Discovery
The compound was discovered by Justus von Liebig and Friedrich Wöhler following the discovery of urea in 1828 and is one of the oldest named organic compounds that exist.
[edit] Etymology
The name is derived from allantoin, a product of uric acid excreted by the fetus into the allantois and oxaluric acid derived from oxalic acid and urea, found in urine.
[edit] Synthesis
The original preparation for alloxan was by oxidation of uric acid by nitric acid. Alloxan is a strong oxidizing agent and it forms a hemiacetal with its reduced reaction product dialuric acid (in which a carbonyl group is reduced to a hydroxyl group) which is called alloxantin.[2]
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Alloxane (left) with dialuric acid (right) and alloxantin (center)
[edit] Commercial use
Alloxane is a raw material for the production of the purple dye murexide. Carl Wilhelm Scheele discovered the dye in 1776. Murexide is the product of the complex in-situ multistep reaction of alloxantin and gaseous ammonia. Murexide results from the condensation of the unisolated intermediate uramil with alloxan, liberated during the course of the reaction.
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Murexide dye (right) from reaction of alloxantin (left)
Scheele sourced uric acid from human calculi (such as kidney stones) and called the compound lithic acid. William Prout investigated the compound in 1818 and he used boa constrictor excrement with up to 90% ammonium acid urate.
Liebig and Wöhler in the nineteenth century coined the name murexide for the dye after the Trunculus Murex which is the source of the Tyrian purple of antiquity.
Primo Levi in his world famous novel The Periodic Table in chapter Nitrogen considers pythons as a source for alloxane on behalf of a lipstick producer but he is turned down by the director of the Turin zoo because the zoo already has lucrative contracts with cosmetics companies.
[edit] Impact upon beta cells
Because it selectively kills the insulin-producing beta-cells found in the pancreas, alloxan is used to induce diabetes in laboratory animals. This occurs most likely because of selective uptake of the compound due to its structural similarity to glucose as well as the beta-cell's highly efficient uptake mechanism (GLUT2). However, alloxan is not toxic to the human beta-cell, even in very high doses, probably due to differing glucose uptake mechanisms in humans and rodents.[3][4]Alloxan is, however, toxic to the liver and the kidneys in high doses.[citation needed]
[edit] References
- ^ Merck Index, 11th Edition, 281.
- ^ Alloxantin dihydrate R. Stuart Tipson Organic Syntheses, Coll. Vol. 4, p.25; Vol. 33, p.3 Online article
- ^ Tyrberg B, Andersson A, Borg L (2001). "Species differences in susceptibility of transplanted and cultured pancreatic islets to the beta-cell toxin alloxan". Gen Comp Endocrinol 122 (3): 238–51. doi:. PMID 11356036.
- ^ Eizirik D, Pipeleers D, Ling Z, Welsh N, Hellerström C, Andersson A (1994). "Major species differences between humans and rodents in the susceptibility to pancreatic beta-cell injury". Proc Natl Acad Sci U S A 91 (20): 9253–6. doi:. PMID 7937750.
