Inositol

Vitamin B class

Inositol belongs to the vitamins B class. Because of the different orientation of the relative ring plane of hydroxyl, it has a total of nine kinds of isomers, including 7 of non-optically active form, two kinds of optically active (L-form and D-form). In nature, it is widely distributed in all living tissues as either free or bound state, and is a common component presented in animal and plant cells. It can be synthesized by gastrointestinal microbes, being involved in carbohydrate and lipid metabolism in the body. It is mainly presented in the form of phosphatidylinositol in animal. It is most abundant in brain, heart and skeletal muscle. It is mainly in the form inositol phosphate in plants, and can bind with calcium, zinc and iron into insoluble compounds, which interfere with their digestion and absorption. Lack of inositol in daily diet can cause hair loss, and negatively affect development. Inositol is related to the intracellular calcium metabolism where its triphosphate derivative can be released from lipid conjugate after cell is stimulated, thus playing a role of secondary messenger. This process can mobilize the intracellular calcium pool to participate in regulation of many cellular events, e.g. secretion, metabolism, cell division, and light transmission.
Inositol is often clinically used together with vitamin B complex, which can prevent or reduce the deposition of excess fat in the liver, and thus promoting the liver fat metabolism. This has a effect on reducing blood lipids, and removing the infiltration effect of the liver cells’ fat. It can be used for treatment of fatty liver, alcohol liver disease, atherosclerosis, high blood cholesterol, diabetes, alopecia, hyperlipidemia and so on. Its derivatives, such as phosphatidylinositol is one of the components of the cell membrane. Phytate (phytic acid) or phytin (phytin) often accumulated in seeds of higher plants. Phytic acid extracted from rice bran or bran can be used as food antioxidants, stabilizers and preservatives.

Since the vast majority of animals and their gastrointestinal microbes can synthesize enough inositol, and food is abundant of inositol, so there are rare cases of inositol deficiency. Many kinds of fish and female gerbils cannot synthesize inositol (The testis tissue of male gerbil can synthesize inositol). Dietary phthaloyl Sulfathiazole can inhibit bacterial synthesis of inositol , which leads to rats’ deficiency of inositol, as follows: the content of free inositol in rat testis, liver, heart, kidney and plasma reduces; Hair loss and dermatitis happens; The content of triglycerides, cholesterol esters in liver increases; Both the size and number of lipid droplets increased significantly; There are also occurrence of fatty liver which can be healed by taking inositol; Moreover, the transport capacity of intestinal mucosal cell for the saturated fat cells decreases , and there is accumulation of intestinal fat. The performance of inositol deficiency for fish is as below: fins degeneration, edema, anemia, decreased gastric emptying rate, and decreased activity of cholinesterase and some transaminase.
The above information is edited by the Chemicalbook of Dai Xiongfeng.

Identification test

Take 1 mL 2% sample solution to a porcelain evaporating dish, add 6ml nitric acid and evaporated to dryness on a water bath. The residue is dissolved with 1mL of water. Add 0.5 mL 10% strontium acetate solution and evaporate it to dryness on a steam bath again. It should display purple.

Content Analysis

Accurately weigh 200 mg sample (pre-dried at 105°C for 4h), and place it into a 250ml beaker. Add 5ml of a mixture between one sulfuric acid (TS-241) testing solution and 50 acetic anhydride, and then cover the watch glass. After heating on a steam bath for 20min, cool it on an ice bath, add 100ml water, and boil 20min. After cooling, transfer the sample into a 250 mL separating funnel using a small amount of water. Successively use 30, 25, 20, 15, 10 and 5 mL of chloroform to extract the solution for six times (first flush the beaker). All the chloroform extract was collected in a second 250m1 separating funnel. Wash the mixed extract with 10ml of water. Put the chloroform solution through a funnel cotton wool and transfer it to a 150ml pre-weighed Soxhlet flask. Use 10ml of chloroform to wash the separating funnel and the funnel, and incorporated into the extract. Evaporate it to dryness on a steam bath, and then transfer it in an oven at 105 °C for drying 1h. Cool it in a desiccator, and weigh it. Use the obtained amount of six inositol acetate multiply by 0.4167, namely the corresponding amount of inositol (C6H12O6).

Toxicity

GRAS (FDA, §182.5370, 2000).

Limited usage

No restrictions (FDA§184.1370,2000).
GB 14880-94 states: infant food, fortified beverages 210~230mg/kg.
GB 2760-2002: Juices (fruit) drinks, 60~120mg/kg.

Permitted levels in food

Chemical Properties

Inositol appears as white crystals or a crystalline powder. It is odorless and has a sweet taste. Its relative density is 1.752 in the anhydrous form and 1.524 in the dihydrate form. It melts at 225–227 °C (anhydrous) and at 218 °C (dihydrate), and boils at approximately 319 °C. It is soluble in water (14 g/100 mL at 25 °C; 28 g/100 mL at 60 °C), slightly soluble in ethanol, acetic acid, ethylene glycol, and glycerol, but insoluble in ether, acetone, and chloroform. It is stable in air and exhibits stability towards heat, acids, and alkalis; however, it is hygroscopic.

Uses

1. As food supplements, has a similar effect to vitamin B1. It can be used for infant foods and used in an amount of 210~250mg/kg; Used in drinking in an amount of 25~30mg/kg.
2. Inositol is an indispensible vitamin for lipid metabolism in the body. It can promote the absorption of hypolipidemic medicines and vitamins. Moreover, it can promote the cell growth and fat metabolism in liver and other tissues. It can be used for the adjuvant treatment of fatty liver, high cholesterol. It is widely used in food and feed additives, and is often added to fish, shrimp and livestock feed. The amount is 350-500mg/kg.
3. The product is one kind of the complex vitamin B, which can promote cell metabolism, improve the cell nutrient conditions, and can contribute to development, increase appetite, to recuperate. Moreover, it can prevent the accumulation of fat in the liver, and accelerate the process of removing excess fat in heart. It has a similar lipid-chemotactic action as choline, and therefore useful in the treatment of hepatic fatty excessive disease and cirrhosis of the liver disease. According to the "food fortifier use of health standards (1993)" (Issued by the Ministry of Health of China), it can be used for infant food and fortified beverages at an amount of 380-790mg/kg. It is a vitamin class medicines and lipid-lowering drug which promote the fat metabolism of liver and other tissues, and be useful for the adjuvant treatment of fatty liver and high cholesterol. It is widely used in additives of food and beverage.
4. Inositol is widely used in pharmaceutical, chemical, food, etc. It has a good effect on treating diseases such as liver cirrhosis. It can also used for advanced cosmetic raw materials, with high economic value.
5. It can be used as a biochemical reagent and also for the pharmaceutical and organic synthesis; It can lower the level cholesterol and have sedative effect.

Production method

1. It is produced by the hydrolysis and the following neutralization of phytin. Add phytin and water into high-pressure hydrolysis pot, seal and heat until pressure gradually rise to around 0.5 MPa; stir for 8 h; check the pH value of the material which should be 2.5-3.0 as the end of the reaction. Add the hydrolyzed liquid into neutralized pot with the milk of lime for neutralization agent. Keep the temperature at 70-80 °C, and the pH value at 7-8. Use centrifuge to throw out filtrate. The Residue can be used for fertilizer (calcium phosphate). Heat the above filtrate to 80-90 °C, put 0.5-0.7% activated carbon, and stir continuously for about 20 min. Use sand core hold for suction filtration. The filtered supernatant is concentrated into condensed pot for condensation for 4-5h at 90 °C. The material can be taken out when the relative density reaches 1.24-1.28, then add enamel barrels or stainless steel barrel for cooling. When the crystal appears, artificially stir and cool to 20-25 °C, send into the centrifuge for drying and obtain the yellow crude product of inositol. Throw out the crude stock solution for another round of condensation and crystallization. Add water or line liquid to the crude product, dissolve it by heating, add active carbon for decoloration; Then add solution of barium oxide and ammonium oxalate to precipitate and remove the sulfate and calcium ions. Filter (when the mixture is still hot) and the filtrate was cooled to 30 °C, crystallize, filter (liquor apply), wash the filtered pellet with ethanol, dry at 80 °C for 6h, and finally go through 18 mesh sieve to obtain inositol.
2. Production Method (1) Sock 1 part of bran meal and 10 parts of water into the immersion pool, Use hydrochloric acid or sulfuric acid to adjust pH till 2.5-3.0, then soak 4-8h at room temperature (longer for winter, shorter for summer). In this case, the insoluble potassium, calcium and magnesium complex salts of plant acid in bran meal are converted into soluble complex salts. Filter and wash the residue with water. The residues can be used for feed. Mix the filtrate and washings and stir using compressed air, then add fresh lime milk to neutralize till pH 6.8. The neutralized mixture was allowed to stand for 2h for thoroughly calcium phytate precipitation. Suck out the supernatant in the upper layer, add clean water to wash repeatedly until washing liquid does not exhibit light yellow (neutral). Apply filter press to filter the lower layer of white slurry to obtain pasty-calcium phytic acid namely phytin. Pour paste phytin and water into high pressure hydrolysis pot for mashing. The concentration should be kept at 25%, and heated to an internal pressure 0.5 MPa, Stirring reaction should be kept for 8h with the pH 2.5-3.0. Add hydrolysis solution into neutralization pot, and neutralize at 70-80 °C with lime milk to pH 7-8. Filter and remove the residue which can be used for fertilizer. Adding catalyst can reduce the reaction temperature and shorten the reaction time.
Heat the hydrolysis solution to 80-90 °C, add 0.5%-0.7% of activated carbon, filter after decoloration. Condense the filtrate for 4-5 hour at 90 °C. Take the materials out when the relative density reaches 1.24-1.28. Cool it to 20-25 °C and crystallize to isolate the yellow inositol crude. Condense and crystallize the filtrate again.
Heat the crude product and dissolve in water. Add active carbon for decolorization. Add barium hydroxide solution and ammonium oxalate solution to precipitate and remove the sulfate and calcium ions. Filter (when the mixture is still hot) and the filtrate was cooled to 30 °C, crystallize, filter (liquor apply), wash the filtered pellet with ethanol, dry at 80 °C for 6h, and finally go through 18 mesh sieve to obtain inositol.
(2) Use the bran as raw material. Soaked it at 30 °C using 1%-1.5% hydrochloric acid for 4-8h, filter it through a plate and frame filter press. Soak the residue for 2 times and neutralize the filtrate with milk of lime until PH value = 7, stir thoroughly for 10min, filter, wash to get the crude product of phytate. The crude product is then dissolved in hydrochloric acid solution (pH = 1-2) and subject to decoloration and filter by activated carbon. Adjust the pH filtrate to pH= 4.5 using 10% Na2CO3 solution stir for 10min, stand for 1-1.5h. Discard the upper layer of supernatant. Place the slurry of calcium phytic acid into a pressure cooker with the subsequent process the same as above.

Description

Inositol (hexahydroxycyclohexane) is a widely distributed natural constituent of plant and animal tissues. The animal tissues richest in inositol are the 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 the 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.

Chemical Properties

Inositol is a cyclic carbohydrate with the molecular formula C₆H₁₂O₆ and a relative molecular mass of 180.16. It appears as white crystals or a white crystalline powder, is odourless, has a slightly sweet taste, readily absorbs moisture, and has a melting point of 220–225 °C and a boiling point of 319 °C. It is readily soluble in water, forming a neutral aqueous solution, and slightly soluble in organic solvents such as alcohol, glacial acetic acid, and glycerol. Research indicates that thermally fused inositol forms metastable amorphous crystals under freezing conditions.

Containing six hydroxyl groups, inositol is also known as cyclohexanehexol. Theoretically, nine possible isomers exist: myo-inositol (MI), D-chiro-inositol (DCI), allo-inositol, cis-inositol, epi-inositol, muco-inositol, neo-inositol, scyllo-inositol, and L-chiro-inositol (LCI). Among these, DCI and LCI lack a plane of symmetry and are thus chiral molecules. Inositol typically exists in a free form within animal organisms, with MI and DCI performing multiple biological functions.

Originator

Inositol,Comm. Solvents,US,1949

Uses

Myo-inositol is a growth factor for animals and microorganisms. It is the most abundant form of polyol and serves as a structural element of secondary messengers in eukaryotic cells. It forms the structural basis for a number of signaling and secondary messenger molecules involved in various processes, including insulin signal transduction, cytoskeleton assembly, nerve guidance, regulation of membrane potentials, serotonin activity, and the breakdown of fats and reduction of cholesterol. It is used as an adulterant in many illegal drugs, such as cocaine and methamphetamine. Furthermore, it is used as a stand-in for cocaine in television and film.

Definition

ChEBI: Inositol is an inositol having myo-configuration. It is a natural sugar found in cell membrane phospholipids, plasma lipoproteins, and (as the phosphate form) in the nucleus with potential chemopreventive properties. As one of a number of intracellular phosphate compounds, inositol is involved in cell signaling and may stimulate tumor cell differentiation.

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.
[3] YUNJIE LI. Production of myo-inositol: Recent advance and prospective[J]. Biotechnology and applied biochemistry, 2021, 69 3: 1101-1111. DOI:10.1002/bab.2181.