L-Glucose

From Wikipedia, the free encyclopedia
Jump to: navigation, search
L-Glucose
L-Glucose structure.svg
Names
IUPAC name
L-Glucose
Identifiers
Abbreviations L-Glc
921-60-8 N
ChEBI CHEBI:37627 YesY
ChemSpider 2006622 YesY
EC number 213-068-3
Jmol-3D images Image
PubChem 2724488
Properties
C6H12O6
Molar mass 180.16 g·mol−1
Density 1.54 g/cm3
91 g/100 mL
Hazards
MSDS ICSC 0865
EU Index not listed
Except where noted otherwise, data is given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 N verify (what isYesY/N?)
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 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.  edit
  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 .
  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