Dihydroxyacetone

White solid

Fixed

75-80 ° C ( mixture of monomer and dimer)

Well in water (930 g · l-1 at 20 ° C)

Template: Infobox chemical / molecular formula search available

Dihydroxyacetone ( DHA abbreviated, Glyceron ) is an amazingly simple carbohydrate with the molecular formula C3H6O3. Since dihydroxyacetone has no stereogenic center, it really is not considered a monosaccharide. However, it is much involved in carbohydrate metabolism. DHA is the essential ingredient of self-tanners and reacts with proteins in the stratum corneum - the outermost skin layer, which thereby einfärbt to brown.

Chemical Properties

Dihydroxyacetone is a white hygroscopic powder with characteristic aroma and sweet taste. It belongs to the group of sugar and in the latter, because of the three carbon atoms of which the molecule is made up of the trioses. The simplest conceivable ketosis, the molecule has no chiral center and is optically inactive. Dihydroxyacetone is in the solid state usually present as a dimer, which quickly splits after solution in water in the monomer. This reaction follows a first order rate law. The half-life of 20.4 minutes at room temperature.

Production

Dihydroxyacetone can, similar to glyceraldehyde by oxidation of glycerol with mild oxidizing agents, such as diluted solution of hydrogen peroxide in the presence of iron salts as catalyst, can be produced. The Large-scale production is carried biotechnology worldwide by the microbial fermentation of glycerol by Gluconobacter oxydans in the order of about 2,000 tons per year. An alternative to this relatively complex technology is the newly developed anodic oxidation in the presence of the catalyst 2,2,6,6- tetramethylpiperidinyloxyl (TEMPO ).

Biological Significance

Of particular importance in biochemistry is a phosphoric acid ester of the dihydroxyacetone, dihydroxyacetone (shown here as an anion, as it usually occurs under physiological conditions ).

Its importance in the metabolic physiology is that it is an important isomer glyceraldehyde -3 -phosphate. The interconversion occurs via the base- catalyzed Lobry -de Bruyn - Alberda -van- Ekenstein rearrangement. The following figure shows the residual R is the group -CH 2- OH:

Like their phosphoric acid esters are also dihydroxyacetone and glyceraldehyde each isomer. They also stand by the above rearrangement in chemical equilibrium. In the cell these equilibrium reactions are catalyzed by certain enzymes.