Allantoin

• N- (2,5- dioxo -4- imidazolidinyl ) urea
• Glyoxylsäurediureid
• 5 -ureido -hydantoin

Colorless solid

Fixed

~ 1.7 g · cm -3

225-236 ° C ( decomposition)

Poorly in water ( 5.7 g · l-1 at 25 ° C), almost insoluble in ethanol

Attention

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Allantoin is a primary final product of the degradation of nucleic acids, in particular of purines in various animal species, especially mammals, in addition to uric acid. It was around the year 1800 by Louis -Nicolas Vauquelin and Buniva discovered in the bodily fluid that fills the allantois of cows, and it has its name. Later, the compound was isolated from the urine of young calves and, in cooperation with Justus Liebig studied by Friedrich Wöhler. These researchers first realized the connection with the uric acid, from which they received allantoin by oxidation with lead dioxide.

Allantoin was synthetically prepared by heating urea with glyoxylic acid to 100 ° C are obtained. Instead of glyoxylic acid can be industrially dichloroacetic acid are used. The production of uric acid has been optimized as the oxidizing agent potassium permanganate in alkaline solution ( sodium hydroxide ) is used.

Use

Allantoin is used in cosmetics in skin creams, shower gels, sunscreens, shaving lotions, in toothpaste and in remedies for excessive sweating ( hyperhidrosis ) and skin irritation. It causes the acceleration of cell structure, cell formation, or cell regeneration and soothes the skin. It also promotes healing of stubborn wounds supported, but allantoin has no antiseptic properties.

Occurrence

Allantoin is in some native plants (especially comfrey ) active ingredient present. Especially in black salsify, but also in wheat germ, soy sprouts, rice, cauliflower, green beans and horse chestnut can find allantoin. The larvae of Lucilia sericata ( Goldfliegenart ) can be used as a means of healing, because they eat very specific necrotic tissue and release large amounts of allantoin.

Other properties

Comfrey ointment that was in naturopathy long as the best sore ointment was prepared by a fat extract of the fresh root with lard. The active substance is thermally stable but sensitive to contact with metal, which can effect catalytic decomposition. Therefore, preparations with allantoin should not be stored in metal containers.