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Erythrulose

Erythrulose
D-erythrulose Fischer.png
D-erythrulose.png
Names
IUPAC name
(R)-1,3,4-Trihydroxybutan-2-one
Other names
D-Erythrulose
Glycerotetrulose
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
PubChem CID
Properties
C4H8O4
Molar mass 120.104g/mol
Appearance Syrup
Soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY  (what is YesYN ?)
Infobox references

D-Erythrulose (also known as erythrulose) is a tetrose carbohydrate with the chemical formula C4H8O4. It has one ketone group and so is part of the ketose family. It is used in some self-tanning cosmetics, in general, combined with dihydroxyacetone (DHA).

Erythrulose/DHA reacts with the amino acids in the proteins of the first layers of skin (the stratum corneum and epidermis). One of the pathways involves free radicals at one of the steps of the Maillard reaction, distantly related to the browning effect when a cut apple slice is exposed to oxygen. The other pathway is the conventional Maillard reaction; both pathways are involved in the browning during food preparation and storage. This is not a stain or dye, but rather a chemical reaction that produces a color change on all treated skin. It does not involve the underlying skin pigmentation nor does it require exposure to ultraviolet light to initiate the color change. However, the 'tan' produced by erythrulose/DHA only has an SPF of up to 3, and enhances the free radical injury from UV (compared to untreated skin) for the 24 hours after self-tanner is applied, according to a 2007 study led by Katinka Jung of the Gematria Test Lab in Berlin. Forty minutes after the researchers treated skin samples with high levels of erythrulose they found that more than 140 percent additional free radicals formed during sun exposure compared with untreated skin.

DHA produced similar results, but faster; however erythrulose takes longer to develop its full effect, therefore it lasts longer. For a day after self-tanner application, excessive sun exposure should be avoided and sunscreen should be worn outdoors, they say; an antioxidant cream could also minimize free radical production. Although some self-tanners contain sunscreen, its effect will not last as long as the tan. During UV irradiation free radicals, mainly superoxide/hydroperoxyl (O2•−/HO2), and other reactive species (ROS/RNS) are produced, that can react with the ketoamines (Amadori products) and other intermediates of the Maillard reaction. This leads to autoxidationradical chain reactions of the ketoamines, which cause a dramatic increase in the radical injury of the skin. This can be suppressed by antioxidants, which shows involvement of reactive oxygen species (ROS). The ketoamines were shown to cause DNA strand breaks and to act as mutagens.


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