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|Section2= |Section6= |Section7= }} Inositol or cyclohexane-1,2,3,4,5,6-hexol is a chemical compound with formula 6126 or (-CHOH-)6, a six-fold alcohol (polyol) of cyclohexane. It exists in nine possible stereoisomers, of which the most prominent form, widely occurring in nature, is ''cis''-1,2,3,5-''trans''-4,6-cyclohexanehexol, or ''myo''-inositol (former names meso-inositol or i-inositol).〔(Synonyms in PubChem )〕〔(Synonyms in Commonchemistry.org )〕 Inositol is a sugar alcohol. Its taste has been assayed at half the sweetness of table sugar (sucrose). ''myo''-Inositol plays an important role as the structural basis for a number of secondary messengers in eukaryotic cells, the various inositol phosphates. In addition, inositol serves as an important component of the structural lipids phosphatidylinositol (PI) and its various phosphates, the phosphatidylinositol phosphate (PIP) lipids. Inositol or its phosphates and associated lipids are found in many foods, in particular fruit, especially cantaloupe and oranges. In plants, the hexaphosphate of inositol, phytic acid or its salts, the phytates, are found. These serve as phosphate stores in the seed. Phytic acid occurs also in cereals with high bran content and also nuts and beans. Yet, inositol, when present as phytate, is not directly bioavailable to humans in the diet, since it is not digestible. Some food preparation techniques partly break down phytates to change this. Inositol as it occurs in certain plant-derived substances such as lecithins, however, is well-absorbed and relatively bioavailable. ''myo''-Inositol (free of phosphate) was once considered a member of the vitamin B complex (formerly Vitamin B8); however, because it is produced by the human body from glucose, it is not an essential nutrient. Some substances such as niacin can also be synthesized in the body, but are not made in amounts considered adequate for good health, thus are still classified as essential nutrients. However, no convincing evidence indicates this is the case for ''myo''-inositol. ==Isomers and structure== The isomer ''myo''-inositol is a meso compound possessing an optically inactive plane of symmetry through the molecule, and ''meso''-inositol is an obsolete name that refers to ''myo''-inositol. Besides ''myo''-inositol, the other naturally occurring stereoisomers (though in minimal quantities) are ''scyllo''-, ''muco''-, -, and ''neo''-inositol. The other possible isomers are -, ''allo''-, ''epi''-, and ''cis''-inositol. As their name denotes, the two ''chiro'' inositols are the only pair of inositol enantiomers, but they are enantiomers of each other, not of ''myo''-inositol. In its most stable conformational geometry, the ''myo''-inositol isomer assumes the chair conformation, which puts the maximum number of hydroxyls to the equatorial position, where they are farthest apart from each other. In this conformation, the natural ''myo'' isomer has a structure in which five of the six hydroxyls (the first, third, fourth, fifth, and sixth) are equatorial, whereas the second hydroxyl group is axial. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Inositol」の詳細全文を読む スポンサード リンク
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