Alloxan

from Wikipedia, the free encyclopedia
Structural formula
Structure of Alloxan
General
Surname Alloxan
other names
  • Mesoxalylurea
  • Mesoxalyl carbamide
  • Tetraoxypyrimidine
  • Dioxyuracil
  • 2,4,5,6 (1 H , 3 H ) -Pyrimidintetron
Molecular formula
  • C 4 H 2 N 2 O 4 (alloxane)
  • C 4 H 2 N 2 O 4 H 2 O (alloxane hydrate )
Brief description

dark yellow crystals

External identifiers / databases
CAS number
  • 50-71-5 (alloxan)
  • 2244-11-3 (alloxane monohydrate)
EC number 200-062-0
ECHA InfoCard 100,000,057
PubChem 5781
ChemSpider 5577
Wikidata Q417701
properties
Molar mass 160.09 g mol −1 (alloxane hydrate)
Physical state

firmly

Melting point

256 ° C (decomposition) (alloxane hydrate)

solubility

soluble in water, ethanol and acetone

safety instructions
GHS labeling of hazardous substances
07 - Warning

Caution

H and P phrases H: 302-312-332
P: 302 + 352
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Alloxan is a heterocyclic organic compound with a pyrimidine skeleton . The compound has a high affinity for water and therefore occurs as a monohydrate .

history

Alloxan was discovered by Justus von Liebig and Friedrich Wöhler shortly after the discovery of urea in 1828 and is one of the oldest named organic substances. Its name is derived from allantoin , which occurs in urine . Even before Liebig and Wöhler it was won in Italy in 1818 by the chemistry professor in Pavia Gaspare Brugnatelli (1795-1825).

Extraction and presentation

Originally alloxan was by oxidation of uric acid with nitric won. Today it is represented as a solvent through the oxidation of barbituric acid with chromium (VI) oxide in acetic acid / water .

properties

Alloxan is a strong oxidant and forms with dialuric acid a hemiacetal that alloxantine is called.

Alloxan (left) with dialuric acid can react to alloxantin (right).

use

Alloxan is a raw material for the purple dye murexide, which was discovered by Karl Wilhelm Scheele in 1776 . Murexide is the product of a complicated multi-stage reaction of alloxantin , which can be obtained from alloxan, with gaseous ammonia .

Reaction of alloxantin (left) to murexide (right). Gaseous ammonia is used in this multi-stage reaction.

Alloxan diabetes

In animal experiments, alloxan triggers diabetes mellitus by destroying the insulin- producing β cells in the pancreas , which is used to create alloxan-diabetic test animals for scientific studies .

literature

  • A. Jorns, R. Munday, M. Tiedge, S. Lenzen: Comparative toxicity of alloxan, N-alkylalloxans and ninhydrin to isolated pancreatic islets in vitro. In: Journal of Endocrinology. 155, 1997, pp. 283-293, doi : 10.1677 / joe.0.1550283 .

Individual evidence

  1. ↑ Entry on Alloxan. In: Römpp Online . Georg Thieme Verlag, accessed on 18 August 2019 .
  2. ↑ a b c d data sheet Alloxan monohydrate, 98% at AlfaAesar, accessed on December 7, 2019 ( PDF )(JavaScript required) .
  3. ↑ External identifiers or database links to alloxan monohydrate : CAS number: 2244-11-3, EC number: 607-078-0, ECHA InfoCard: 100.130.041 , PubChem : 16723 , ChemSpider : 15854 , Wikidata : Q72437128 .
  4. ^ Ugo Baldini: Luigi Valentino Brugnatelli , in Dizionario Biografico degli Italiani, 1972.
  5. ^ AV Holmgren and Wilhelm Wenner: Alloxan Monohydrate In: Organic Syntheses . 32, 1952, p. 6, doi : 10.15227 / orgsyn.032.0006 ; Coll. Vol. 4, 1963, p. 23 ( PDF ).
  6. ^ S. Lenzen: The mechanisms of alloxan- and streptozotocin-induced diabetes. In: Diabetologia . Volume 51, Number 2, February 2008, pp. 216-226, doi : 10.1007 / s00125-007-0886-7 , PMID 18087688 .
  7. ↑ IF Federiuk, HM Casey u. a .: Induction of type-1 diabetes mellitus in laboratory rats by use of alloxan: route of administration, pitfalls, and insulin treatment. In: Comparative medicine. Volume 54, Number 3, June 2004, pp. 252-257, PMID 15253270 .