Alloxan

Description

Alloxan is a thermally stable white solid with an unusual structure. Its formal name is 2,4,5,6(1H,3H)-pyrimidinetetrone, indicating that it has a pyrimidine ring structure with four carbonyl groups. It is freely soluble in water, forming a slightly acidic solution. The solid begins to decompose at 256 oC.
In 1818, Italian chemist Luigi V. Brugnatelli was the first to isolate alloxan; he synthesized it via nitric acid oxidative degradation of uric acid. Shortly after Friedrich W?hler found that urea can be made from inorganic materials in 1828, he and Justus von Liebig discovered alloxan in human excretions, showing that it also can be biosynthesized. Currently, alloxan is prepared from barbituric acid or alloxantin; the article of commerce is the monohydrate.
Alloxan is sometimes used in dye manufacture, but its main (and most notorious) use is to induce diabetes in laboratory rodents. Alloxan’s structure mimics that of glucose, which allows it to be absorbed by the pancreas. Once inside the organ, it destroys insulin-producing β-cells and produces a disease similar to type 1 diabetes in humans. Fortunately, alloxan is not taken up by the human pancreas, but it has shown liver and kidney toxicity.

Chemical properties

Alloxan is a white crystals, become pink on exposure to air; colorless aqueous solution which imparts pink color to skin. Soluble in water and alcohol.

The Uses of Alloxan

Alloxan is used in biochemical research, cosmetics, organic synthesis.

Definition

ChEBI: A member of the class of pyrimidones, the structure of which is that of perhydropyrimidine substituted at C-2, -4, -5 and -6 by oxo groups.

Safety Profile

Poison by intraperitoneal, intravenous, subcutaneous, and rectal routes. Moderately toxic by ingestion. An experimental teratogen. Other experimental reproductive effects. Mutation data reported. Produces dlabetes in experimental animals. Decomposes in storage to release CO2. Do not store in sealed container. Explodes when heated above 170℃. When heated to decomposition it emits toxic fumes of NOx,.

Purification Methods

Crystallisation from water gives the tetrahydrate. Anhydrous crystals are obtained by crystallisation from acetone, glacial acetic acid or by sublimation in vacuo. [See below and Beilstein 24 H 500, 24 I 428, 24 II 301, 24 III/IV 2137.]