5-Deoxyinositol Explained
5-Deoxyinositol (quercitol) is a cyclitol. It can be found in wines aged in oak wood barrels.[1] It can also be found in Quercus sp. (oaks)[2] and in Gymnema sylvestre. It is different from, a synonym of quercetin.
Biosynthesis
The proposed biosynthesis of 5-deoxyinositol begins with the conversion of D-glucose to myo-inositol.[3] 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,[4] 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.
Notes and References
- Occurrence and Significance of Quercitol and Other Inositols in Wines during Oak Wood Aging . Davinia Carlavilla . Mar Villamiel . Isabel Martínez-Castro . M. Victoria Moreno-Arribas . amp . Am. J. Enol. Vitic. . 57 . 4 . 468–473 . 2006. 10.5344/ajev.2006.57.4.468 . 83679744 .
- Analysis of cyclitols in different Quercus species by gas chromatography–mass spectrometry . Sonia Rodríguez-Sánchez . Ana I Ruiz-Matute . María Elena Alañón. María Soledad Pérez-Coello . Luis F de Julio-Torres. Ramón Morales . Isabel Martínez-Castro . amp . Journal of the Science of Food and Agriculture . 90 . 10 . 1735–1738 . 2010 . 10.1002/jsfa.4009. 20564438 . 2010JSFA...90.1735R .
- 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 . 10.1016/s0005-2760(97)00122-7 . 0006-3002 . 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 . 10.1074/jbc.M708043200 . 0021-9258 . 18310071. free .