L-Glucose

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L-Glucose
L-Glucose structure.svg
Haworth projection of α-L-Glucopyranose.svg
Haworth projection of α-L-Glucopyranose
Names
IUPAC name
L-Glucose
Identifiers
3D model (JSmol)
Abbreviations L-Glc
ChEBI
ChemSpider
ECHA InfoCard 100.011.881
EC Number 213-068-3
Properties
C6H12O6
Molar mass 180.16 g·mol−1
Density 1.54 g/cm3
91 g/100 mL
Hazards
Safety data sheet ICSC 0865
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

L-Glucose is an organic compound with formula C6H12O6 or H–(C=O)–(CHOH)5–H, specifically one of the aldohexose monosaccharides. As the L-isomer of glucose, it is the enantiomer of the more common D-glucose.

L-Glucose does not occur naturally in higher living organisms, but can be synthesized in the laboratory. L-Glucose is indistinguishable in taste from D-glucose,[1] but cannot be used by living organisms as a source of energy because it cannot be phosphorylated by hexokinase, the first enzyme in the glycolysis pathway. One of the known exceptions is in Burkholderia caryophylli, a plant pathogenic bacterium, which contains the enzyme D-threo-aldose 1-dehydrogenase which is capable of oxidizing L-glucose.[2]

Like the D-isomer, L-glucose usually occurs as one of four cyclic structural isomers — α- and β-L-glucopyranose (the most common, with a six-atom ring), and α- and β-L-glucofuranose (with a five-atom ring). In water solution, these isomers interconvert in matters of hours, with the open-chain form as an intermediate stage.

Uses[edit]

L-Glucose was once proposed as a low-calorie sweetener and it is suitable for patients with diabetes mellitus, but it was never marketed due to excessive manufacturing costs.[1]

The acetate derivative of L-glucose, L-glucose pentaacetate, was found to stimulate insulin release, and might therefore be of therapeutic value for type 2 diabetes.[3] L-Glucose was also found to be a laxative, and has been proposed as a colon-cleansing agent which would not produce the disruption of fluid and electrolyte levels associated with the significant liquid quantities of bad-tasting osmotic laxatives conventionally used in preparation for colonoscopy.[4]

References[edit]

  1. ^ a b A Natural Way to Stay Sweet, NASA, retrieved 2009-09-02 .
  2. ^ Sasajima, K.; Sinskey, A. (1979). "Oxidation of l-glucose by a Pseudomonad". Biochimica et Biophysica Acta (BBA) - Enzymology. 571: 120–126. doi:10.1016/0005-2744(79)90232-8. PMID 40609. 
  3. ^ Malaisse, W. J. (1998), "The riddle of L-glucose pentaacetate insulinotropic action", Int. J. Mol. Med., 2 (4): 383–88, doi:10.3892/ijmm.2.4.383, archived from the original on 2011-07-16 .
  4. ^ Raymer, Geoffrey S.; Hartman, Donald E.; Rowe, William A.; Werkman, Robert F.; Koch, Kenneth L. (2003), "An open-label trial of L-glucose as a colon-cleansing agent before colonoscopy", Gastrointest. Endosc., 58 (1): 30–35, doi:10.1067/mge.2003.293, PMID 12838217