5-Deoxyinositol (quercitol) is a cyclitol. It can be found in wines aged in oak wood barrels.[2] It can also be found in Quercus sp. (oaks)[3] and in Gymnema sylvestre. It is different from quercetol, a synonym of quercetin.
Names | |
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Preferred IUPAC name
(1R,2S,4S,5R)-Cyclohexane-1,2,3,4,5-pentol | |
Other names
Viburnitol; d-Quercitol; (+)-Quercitol; Proto-quercitol; Acorn sugar
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Identifiers | |
3D model (JSmol)
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ChemSpider | |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties[1] | |
C6H12O5 | |
Molar mass | 164.157 g·mol−1 |
Appearance | Crystalline solid |
Melting point | 234 to 235 °C (453 to 455 °F; 507 to 508 K) |
Soluble | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Biosynthesis
editThe proposed biosynthesis of 5-deoxyinositol begins with the conversion of D-glucose to myo-inositol.[4] In this pathway, D-glucose is phosphorylated to form D-glucose-6-phosphate. The NAD+ dependent enzyme inositol 1-phosphate synthase (I1PS) then catalyzes the subsequent oxidation, enolization, aldol cyclization, and reduction of D-glucose 6-phosphate to form myo-inositol 1-phosphate. Hydrolysis of the phosphate group on this molecule gives myo-inositol. Myo-inositol can then be converted into 5-deoxyinositol in three steps,[5] beginning with the oxidation of myo-inositol by inositol dehydrogenase (ID) to form scyllo-inosose. This intermediate is then dehydrated to form a diketone. The reduction of this diketone gives 5-deoxyinositol. This final reduction is thought to be catalyzed by one or more unidentified reductases or dehydrogenases.
References
edit- ^ Merck Index, 12th Edition, 8218
- ^ Davinia Carlavilla; Mar Villamiel; Isabel Martínez-Castro & M. Victoria Moreno-Arribas (2006). "Occurrence and Significance of Quercitol and Other Inositols in Wines during Oak Wood Aging". Am. J. Enol. Vitic. 57 (4): 468–473. doi:10.5344/ajev.2006.57.4.468. S2CID 83679744.
- ^ Sonia Rodríguez-Sánchez; Ana I Ruiz-Matute; María Elena Alañón; María Soledad Pérez-Coello; Luis F de Julio-Torres; Ramón Morales & Isabel Martínez-Castro (2010). "Analysis of cyclitols in different Quercus species by gas chromatography–mass spectrometry". Journal of the Science of Food and Agriculture. 90 (10): 1735–1738. Bibcode:2010JSFA...90.1735R. doi:10.1002/jsfa.4009. PMID 20564438.
- ^ Majumder, A. L.; Johnson, M. D.; Henry, S. A. (1997-09-04). "1L-myo-inositol-1-phosphate synthase". Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 1348 (1–2): 245–256. doi:10.1016/s0005-2760(97)00122-7. ISSN 0006-3002. PMID 9370339.
- ^ Yoshida, Ken-ichi; Yamaguchi, Masanori; Morinaga, Tetsuro; Kinehara, Masaki; Ikeuchi, Maya; Ashida, Hitoshi; Fujita, Yasutaro (2008-04-18). "myo-Inositol catabolism in Bacillus subtilis". The Journal of Biological Chemistry. 283 (16): 10415–10424. doi:10.1074/jbc.M708043200. ISSN 0021-9258. PMID 18310071.