Glyceraldehyde (glyceral) is a triose monosaccharide with chemical formula C3H6O3. It is the simplest of all common aldoses. It is a sweet, colorless, crystalline solid that is an intermediate compound in carbohydrate metabolism. The word comes from combining glycerol and aldehyde, as glyceraldehyde is glycerol with one hydroxymethyl group oxidized to an aldehyde.
|Systematic IUPAC name
3D model (JSmol)
|Molar mass||90.078 g·mol−1|
|Melting point||145 °C (293 °F; 418 K)|
|Boiling point||140 to 150 °C (284 to 302 °F; 413 to 423 K) at 0.8 mmHg|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
- In the d/l nomenclature, either d from Latin Dexter meaning "right", or l from Latin Laevo meaning "left"
- In the R/S nomenclature, either R from Latin Rectus meaning "right", or S from Latin Sinister meaning "left"
While the optical rotation of glyceraldehyde is (+) for R and (−) for L, this is not true for all monosaccharides. The stereochemical configuration can only be determined from the chemical structure, whereas the optical rotation can only be determined empirically (by experiment).
In the d/l system, glyceraldehyde is used as the configurational standard for carbohydrates. Monosaccharides with an absolute configuration identical to (R)-glyceraldehyde at the last stereocentre, for example C5 in glucose, are assigned the stereo-descriptor d-. Those similar to (S)-glyceraldehyde are assigned an l-.
Glyceraldehyde can be prepared, along with dihydroxyacetone, by the mild oxidation of glycerol, for example with hydrogen peroxide and a ferrous salt as catalyst. Dihydroxyacetone, the simplest ketose, is an isomer of glyceraldehyde.
The interconversion of the phosphates of glyceraldehyde (glyceraldehyde 3-phosphate) and dihydroxyacetone (dihydroxyacetone phosphate), catalyzed by the enzyme triosephosphate isomerase, is an important intermediate step in glycolysis.