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Glycolaldehyde (HOCH2-CH=O) is the smallest possible molecule that contains both an aldehyde group and a hydroxyl group. It is the only possible diose, a 2-carbon monosaccharide, although a diose is not strictly a saccharide. It is the simplest possible sugar.[1]
Formation
Glycolaldehyde is an intermediate in the formose reaction.
Glycolaldehyde forms from many precursors, including the amino acid glycine. It can form by action of ketolase on fructose 1,6-bisphosphate in an alternate glycolysis pathway. This compound is transferred by thiamine pyrophosphate during the pentose phosphate shunt.
In purine catabolism, xanthine is first converted to urate. This is converted to 5-hydroxyisourate, which decarboxylates to allantoin and allantoic acid. After hydrolyzing one urea, this leaves glycolureate. After hydrolyzing the second urea, glycolaldehyde is left. Two glycolaldehydes condense to form erythrose 4-phosphate, which goes to the pentose phosphate shunt again.
In the Media
Glycolaldehyde was identified in a giant cloud of gas and dust near the center of our own Milky Way Galaxy[2] but recently also in star-forming region [3].
Note
- ^ Marstokk, K.-M., & Møllendal, H. (1973). "Microwave Spectra of Isotopic Glycolaldehydes, Substitution Structure, Intramolecular Hydrogen Bond and Dipole Moment". J. Mol. Struct. 19: 259-270, http://folk.uio.no/haraldm/Publikasjoner_pdf/ArtiklerPDF_HM/A11_IsotopicGlycolaldehydes.pdf.
- ^ Hollis, J.M., Lovas, F.J., & Jewell, P.R. (2000). "Interstellar Glycolaldehyde: The First Sugar". The Astrophysical Journal 540: 107-110, http://astrobiology.gsfc.nasa.gov/pdf/2000%20ref/hollis_2000.pdf.
- ^ Beltran, M. T.; Codella, C.; Viti, S.; Neri, R.; Cesaroni, R.; (11/2008). "First detection of glycolaldehyde outside the Galactic Center". eprint arXiv:0811.3821.
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