Inositol can be regarded chemically as a polyalkyl derivative of cyclohexane. There are nine theoretically possible isomers, and four commonly found in nature, known as D-chiro-inositol, L-chiro-inositol, myo-inositol, and scyllo-inositol. One of the most common in nature is myositol. Although the quantity of D-inositol and L-inositol is small, they are widely distributed, and most of them can become methyl ether. Inositol is found in the urine of coconuts, sharks, and mammals. Generally speaking, although inositol is widely distributed, its metabolic pathway or physiological function is not very clear.
Almost all organisms contain inositol in its free or bound form. Inositol hexaphosphate is present as hexaphosphate in the nucleated red blood cells of plants and birds. Compounds less than this compound phosphate group are also distributed in plants and animals, and the free inositol is mainly found in muscles, lungs, liver, and is a phosphatidyl inositol component of phospholipids.
Myositol is an essential nutrient source for birds and mammals. Lack of myositol, such as in mice, can cause hair removal, and in rats, can cause abnormalities around the eyes. Rats can metabolize inositol in large quantities, but not much in urine. Sharks seem to be able to convert inositol into an energy-storing substance. It is one of the components of biotin I.