L-Glucose
| Haworth projection of α-l-glucopyranose | |
| Fischer projection of l-glucose | |
| Names | |
|---|---|
| IUPAC name l-Glucose | |
| Identifiers | |
| 3D model (JSmol) | |
| Abbreviations | L-Glc | 
| ChEBI | |
| ChemSpider | |
| EC Number | 
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| PubChem CID | |
| UNII | |
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| Properties | |
| C6H12O6 | |
| Molar mass | 180.156 g·mol−1 | 
| Density | 1.54 g/cm3 | 
| 91 g/100 mL | |
| Hazards | |
| Safety data sheet (SDS) | ICSC 0865 | 
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references | |
l-Glucose is an organic compound with formula C6H12O6 or O=CH[CH(OH)]5H, 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 living organisms, but can be synthesized in the laboratory. l-Glucose is indistinguishable in taste from d-glucose, 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 Trinickia caryophylli, a plant pathogenic bacterium, which contains the enzyme d-threo-aldose 1-dehydrogenase which is capable of oxidizing l-glucose.
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.