Alloxan

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 Wöhler 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.