Description
Inositol (87-89-8) is a widely distributed natural
constituent of plant and animal tissues. The animal tissues richest
in inositol are brain, heart, stomach, kidney, spleen, and liver,
where it occurs free or as a component of phospholipids. Among
plants, cereals are rich sources of inositol, particularly in the form
of polyphosphoric acid esters, called phytic acids. Although there
are several possible optically active and inactive isomers, considerations of inositol as a food additive refer specifically to optically inactive cis-1,2,3,5-trans-4,6-cyclohexanehexol, which is preferably designated myo-inositol.
Pure inositol is a stable, white, sweet, crystalline compound. The
Food Chemicals Codex specifies that it assay not less than
97.0 percent, melt between 224 and 227°, and contain not more
than 3 ppm arsenic, 10 ppm lead, 20 ppm heavy metals (as Pb),
60 ppm sulfate, and 50 ppm chloride.
Inositol was thought for a time to be a vitamin because experimental animals on a synthetic diet developed clinical signs that
were corrected by inositol supplementation. However, no cofactor
or catalytic function for inositol has been found; it can be synthesized and occurs in relatively high concentration in animal tissues.
These factors argue against its classification as a vitamin. A dietary
requirement in man has not been established.
Originator
Inositol,Comm. Solvents,US,1949
Definition
ChEBI: An inositol having myo- configuration.
Manufacturing Process
Inactive inositol may be prepared from starch factory steep water which is the
liquid in which corn is steeped to soften the covering of the corn kernel and to
thoroughly soften the entire kernel. It contains approximately 1% sulfurous
acid (H2SO3) in solution. A typical example of such treatment consists in
adding to the acid steep water, lime Ca(OH)2 or CaO to approximate
neutrality, or to a pH of 6.0 to 8.0, at which range the insoluble "phytin" is
precipitated. This precipitate of impure "phytin" or calcium phytate is removed
by suitable means, as stated before, and may be mixed with (1) 1 to 10%
acid solution; or (2) diluted with water; or (3) the solution may be made
alkaline. This alkaline or neutral or acid mixture is placed in a suitable
container in an autoclave or steam digester, and the steam turned on
whereupon the reaction is allowed to proceed as long as desired. The
autoclave in which the mixture has been placed may be heated by generating
steam therein, by means of an electric heater, or by suitable heat from
outside. A pressure of from 1 to 200 pounds steam for 1 to 18 hours may be
used, the time required being correspondingly less for higher pressures. A
suitable pressure is 80 pounds. The time expected for 80 pounds is three
hours.
autoclave cooled, the mixture removed, diluted, and made alkaline with
Ca(OH)2, Ba(OH)2,etc., brought to boiling, thoroughly agitated with steam,
the insoluble sludge allowed to settle, and the supernatant liquid removed by
decantation, siphoning or filtration. The supernatant liquid is concentrated in
an open vessel, or in vacuum, to remove the precipitating inorganic impurities
as calcium carbonate (CaCO3), magnesium carbonate (MgCO3), etc. The liquid
is concentrated until it becomes thick and syrupy. The concentrated solution is
filtered, cooled, and agitated by a suitable mechanical means to precipitate iinositol. The iI-inositol is removed by filtration, the mother liquor
concentrated, and the process repeated until the solution becomes too thick to
filter advantageously. A filter press may be employed to remove furtherquantities of i-inositol, or the thick residue may be diluted with a reagent in
which i-inositol is insoluble; as, for example, acetic acid (CH3COOH) and
alcohol-acetic acid (C2H5OH, CH3COOH, etc.). On cooling and stirring the
solution, additional i-inositol, etc., results and can be removed by filtration or
other mechanical means. The i-inositol may be recrystallized by dissolving the
crude product in boiling water, and reprecipitated by cooling and stirring. The
final crystallization from a hot water solution to which an equal volume of
alcohol is added with cooling and stirring, gives a purer product.
Therapeutic Function
Vitamin, Lipotropic
General Description
Myoinositol is a stereoisomeric form of inositol, and is very often found in many plants and in tissues of animals and plants. It acts as a second messenger, thereby is very important for the signal pathways of cells. It generally finds application in being used as a natural insulin sensitizer in PCOS (Polycystic Ovarian Syndrome) patients. Myoinositol acts in a PCOS pathway by improving insulin sensitivity, thereby sequentially increasing intracellular glucose uptake.
Biochem/physiol Actions
A component of membrane phospholipids, glycosyl-phosphatidyl-inositol anchors that bind glycoproteins to cell membranes, and inositol phosphate second messengers.
Side effects
Mild side effects have been reported with doses of 12 grams per day or higher. These include nausea, gas, difficulty sleeping, headache, dizziness and tiredness.
Purification Methods
Recrystallise myo-inositol from aqueous 50% ethanol or H2O forming a dihydrate, or anhydrous crystals from AcOH. The dihydrate is efflorescent and becomes anhydrous when heated at 100o . The anhydrous crystals are not hygroscopic. Its solubility in H2O at 25o is 14%, at 60o it is 28%; it is slightly soluble in EtOH but insoluble in Et2O. [Ballou & Anderson J Am Chem Soc 7 5 748 1953, Anderson & Wallis J Am Chem Soc 70 2931 1948, Beilstein 6 II 1157, 6 IV 7919.]
Clinical claims and research
Some researches have found that inositol enhanced cisplatin-induced histopathological improvements in the uterus and ovaries, raising progesterone and estradiol serum levels. Hence, Inositol shield against cisplatin-related infertility by reducing oxidative stress and apoptosis in the uterus and ovaries. Inositol stereoisomers are naturally occurring molecules that readily cross the blood-brain barrier . It may represent a viable treatment for AD through the complexation of Abeta and attenuation of Abeta neurotoxic effects[1-2].
References
[1] Moslehi A, et al. Fertility-enhancing effects of inositol & vitamin C on cisplatin induced ovarian and uterine toxicity in rats via suppressing oxidative stress and apoptosis. Food and Chemical Toxicology, 2023; 179: 113995.
[2] McLaurin J, et al. Inositol stereoisomers stabilize an oligomeric aggregate of Alzheimer amyloid beta peptide and inhibit abeta -induced toxicity. Journal of Biological Chemistry, 2000; 275: 18495-18502.