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''myo''-Inositol plays an important role as the structural basis for a number of [[secondary messenger]]s in [[eukaryote|eukaryotic]] [[cell (biology)|cells]], the various [[inositol phosphate]]s. In addition, inositol serves as an important component of the structural lipids [[phosphatidylinositol]] (PI) and its various phosphates, the [[phosphatidylinositol phosphate (disambiguation)|phosphatidylinositol phosphate]] (PIP) lipids.
''myo''-Inositol plays an important role as the structural basis for a number of [[secondary messenger]]s in [[eukaryote|eukaryotic]] [[cell (biology)|cells]], the various [[inositol phosphate]]s. In addition, inositol serves as an important component of the structural lipids [[phosphatidylinositol]] (PI) and its various phosphates, the [[phosphatidylinositol phosphate (disambiguation)|phosphatidylinositol phosphate]] (PIP) lipids.


Inositol or its phosphates and associated lipids are found in many foods, in particular fruit, especially [[cantaloupe]] and [[Orange (fruit)|oranges]].<ref>{{cite journal |author1=Clements RS Jr |author2=Darnell B | title=Myo-inositol content of common foods: development of a high-myo-inositol diet | journal=American Journal of Clinical Nutrition | volume=33 | issue=9 | year=1980 | pages=1954–1967 | url = http://www.ajcn.org/content/33/9/1954.long| format = PDF | id= | pmid=7416064}}</ref> 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 [[cereal]]s 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 [[lecithin]]s, however, is well-absorbed and relatively bioavailable.
Inositol or its phosphates and associated lipids are found in many foods, in particular fruit, especially [[cantaloupe]] and [[Orange (fruit)|oranges]].<ref>{{cite journal |vauthors=Clements RS, Darnell B |title=Myo-inositol content of common foods: development of a high-myo-inositol diet |journal=The American Journal of Clinical Nutrition |volume=33 |issue=9 |pages=1954–67 |year=1980 |pmid=7416064 |url=http://www.ajcn.org/cgi/pmidlookup?view=long&pmid=7416064 }}</ref> 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 [[cereal]]s 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 [[lecithin]]s, however, is well-absorbed and relatively bioavailable.


''myo''-Inositol (free of phosphate) was once considered a member of the [[vitamin B]] complex (formerly Vitamin B<sub>8</sub>); however, because it is produced by the human body from [[glucose]], it is not an [[essential nutrient]].<ref>{{cite book | last1 = Reynolds | first1 = James E. F. | title = Martindale: The Extra Pharmacopoeia | volume = 30 | publisher = Rittenhouse Book Distributors | date = January 1, 1993 | location = Pennsylvania | page = 1379<!--| accessdate = 2011-04-16--> | isbn = 0-85369-300-5 | quote = An isomer of glucose that has traditionally been considered to be a B vitamin although it has an uncertain status as a vitamin and a deficiency syndrome has not been identified in man}}</ref> 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.
''myo''-Inositol (free of phosphate) was once considered a member of the [[vitamin B]] complex (formerly Vitamin B<sub>8</sub>); however, because it is produced by the human body from [[glucose]], it is not an [[essential nutrient]].<ref>{{cite book | last1 = Reynolds | first1 = James E. F. | title = Martindale: The Extra Pharmacopoeia | volume = 30 | publisher = Rittenhouse Book Distributors | date = January 1, 1993 | location = Pennsylvania | page = 1379 | isbn = 0-85369-300-5 | quote = An isomer of glucose that has traditionally been considered to be a B vitamin although it has an uncertain status as a vitamin and a deficiency syndrome has not been identified in man}}</ref> 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 ==
== Isomers and structure ==
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In its most stable conformational geometry, the ''myo''-inositol isomer assumes the [[cyclohexane conformation|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 [[hydroxyl]]s (the first, third, fourth, fifth, and sixth) are [[equatorial bond|equatorial]], whereas the second hydroxyl group is [[axis of rotation|axial]].<ref>{{cite book
In its most stable conformational geometry, the ''myo''-inositol isomer assumes the [[cyclohexane conformation|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 [[hydroxyl]]s (the first, third, fourth, fifth, and sixth) are [[equatorial bond|equatorial]], whereas the second hydroxyl group is [[axis of rotation|axial]].<ref>{{cite book
| author = S. M. N. Furse
| author = S. M. N. Furse
| title = The Chemical and Bio-physical properties of Phosphatidylinositol phosphates, Thesis for M.Res.
| title = The Chemical and Bio-physical properties of Phosphatidylinositol phosphates |type=Thesis for M.Res.
| year =2006
| year =2006
| publisher =[[Imperial College London]]
| publisher =[[Imperial College London]]
| isbn = }}</ref>
| isbn = }}{{pn}}{{rs}}</ref>


== Biosynthesis ==
== Biosynthesis ==
''myo''-Inositol is synthesized from [[glucose-6-phosphate]] (G-6-P) in two steps. First, G-6-P is [[isomer]]ised by an [[inositol-3-phosphate synthase]] enzyme (for example, [[ISYNA1]]) to ''myo''-inositol 1-phosphate, which is then dephosphorylated by an [[inositol monophosphatase]] enzyme (for example, [[IMPA1]]) to give free ''myo''-inositol. In humans, most inositol is synthesized in the kidneys, in typical amounts of a few grams per day.<ref>Subcell Biochem. 2006;39:293-314. Mammalian inositol 3-phosphate synthase: its role in the biosynthesis of brain inositol and its clinical use as a psychoactive agent. Parthasarathy LK, Seelan RS, Tobias C, Casanova MF, Parthasarathy RN.</ref>
''myo''-Inositol is synthesized from [[glucose-6-phosphate]] (G-6-P) in two steps. First, G-6-P is [[isomer]]ised by an [[inositol-3-phosphate synthase]] enzyme (for example, [[ISYNA1]]) to ''myo''-inositol 1-phosphate, which is then dephosphorylated by an [[inositol monophosphatase]] enzyme (for example, [[IMPA1]]) to give free ''myo''-inositol. In humans, most inositol is synthesized in the kidneys, in typical amounts of a few grams per day.<ref>{{cite journal |vauthors=Parthasarathy LK, Seelan RS, Tobias C, Casanova MF, Parthasarathy RN |title=Mammalian inositol 3-phosphate synthase: its role in the biosynthesis of brain inositol and its clinical use as a psychoactive agent |journal=Sub-cellular Biochemistry |volume=39 |issue= |pages=293–314 |year=2006 |pmid=17121280 }}</ref>


== Function ==
== Function ==
Inositol and some of its mono- and polyphosphates function as the basis for a number of signaling and secondary messenger molecules. They are involved in a number of biological processes, including:
Inositol and some of its mono- and polyphosphates function as the basis for a number of signaling and secondary messenger molecules. They are involved in a number of biological processes, including:
* [[Insulin]] [[signal transduction]]<ref name="Larner J 2002 47–60">{{cite journal
* [[Insulin]] [[signal transduction]]<ref name="Larner J 2002 47–60">{{cite journal |vauthors=Larner J |title=D-chiro-inositol--its functional role in insulin action and its deficit in insulin resistance |journal=International Journal of Experimental Diabetes Research |volume=3 |issue=1 |pages=47–60 |year=2002 |pmid=11900279 |pmc=2478565 |doi=10.1080/15604280212528 }}</ref>
| author = Larner J
| title = D-chiro-inositol--its functional role in insulin action and its deficit in insulin resistance
| journal = Int J Exp Diabetes Res
| year = 2002
| volume = 3
| issue = 1
| pages = 47–60
| pmid =11900279
| doi = 10.1080/15604280212528
| pmc = 2478565
}}</ref>
* [[Cytoskeleton]] assembly
* [[Cytoskeleton]] assembly
* Nerve guidance ([[epsin]])
* Nerve guidance ([[epsin]])
* [[Intracellular]] [[calcium]] (Ca<sup>2+</sup>) concentration control<ref>Gerasimenko, Julia V; et al; "Bile Acids Induce Ca2+ Release from Both the Endoplasmic Reticulum and Acidic Intracellular Calcium Stores through Activation of Inositol Trisphosphate Receptors and Ryanodine Receptors" Journal of Biological Chemistry; December 29, 2006; Volume 281: Pp 40154-40163.</ref>
* [[Intracellular]] [[calcium]] (Ca<sup>2+</sup>) concentration control<ref>{{cite journal |vauthors=Gerasimenko JV, Flowerdew SE, Voronina SG, Sukhomlin TK, Tepikin AV, Petersen OH, Gerasimenko OV |title=Bile acids induce Ca2+ release from both the endoplasmic reticulum and acidic intracellular calcium stores through activation of inositol trisphosphate receptors and ryanodine receptors |journal=The Journal of Biological Chemistry |volume=281 |issue=52 |pages=40154–63 |year=2006 |pmid=17074764 |doi=10.1074/jbc.M606402200 }}</ref>
* Cell [[membrane potential]] maintenance<ref name="pmid9017197">{{cite journal |vauthors=Kukuljan M, Vergara L, Stojilkovic SS | title = Modulation of the kinetics of inositol 1,4,5-trisphosphate-induced [Ca2+]i oscillations by calcium entry in pituitary gonadotrophs | journal = Biophysical Journal | volume = 72 | issue = 2 Pt 1 | pages = 698–707 |date=February 1997 | pmid = 9017197 | pmc = 1185595 | doi = 10.1016/S0006-3495(97)78706-X| url = | bibcode = 1997BpJ....72..698K }}</ref>
* Cell [[membrane potential]] maintenance<ref name="pmid9017197">{{cite journal |vauthors=Kukuljan M, Vergara L, Stojilkovic SS |title=Modulation of the kinetics of inositol 1,4,5-trisphosphate-induced [Ca2+]i oscillations by calcium entry in pituitary gonadotrophs |journal=Biophysical Journal |volume=72 |issue=2 Pt 1 |pages=698–707 |year=1997 |pmid=9017197 |pmc=1185595 |doi=10.1016/S0006-3495(97)78706-X |bibcode=1997BpJ....72..698K }}</ref>
* Breakdown of [[fat]]s <ref name="pmid3103610">{{cite journal |vauthors=Rapiejko PJ, Northup JK, Evans T, Brown JE, Malbon CC | title = G-proteins of fat-cells. Role in hormonal regulation of intracellular inositol 1,4,5-trisphosphate | journal = The Biochemical Journal | volume = 240 | issue = 1 | pages = 35–40 |date=November 1986 | pmid = 3103610 | pmc = 1147372 | doi = | url = }}</ref>
* Breakdown of [[fat]]s <ref name="pmid3103610">{{cite journal |vauthors=Rapiejko PJ, Northup JK, Evans T, Brown JE, Malbon CC |title=G-proteins of fat-cells. Role in hormonal regulation of intracellular inositol 1,4,5-trisphosphate |journal=The Biochemical Journal |volume=240 |issue=1 |pages=35–40 |year=1986 |pmid=3103610 |pmc=1147372 |url=http://www.biochemj.org/cgi/pmidlookup?view=long&pmid=3103610 }}</ref>
* [[Gene expression]]<ref>{{cite journal |vauthors=Shen X, Xiao H, Ranallo R, Wu WH, Wu C |title=Modulation of ATP-dependent chromatin-remodeling complexes by inositol polyphosphates |journal=Science |volume=299 |issue=5603 |pages=112–4 |year=2003 |pmid=12434013 |doi=10.1126/science.1078068 }}</ref><ref>{{cite journal |vauthors=Steger DJ, Haswell ES, Miller AL, Wente SR, O'Shea EK |title=Regulation of chromatin remodeling by inositol polyphosphates |journal=Science |volume=299 |issue=5603 |pages=114–6 |year=2003 |pmid=12434012 |pmc=1458531 |doi=10.1126/science.1078062 }}</ref>
* [[Gene expression]]<ref>{{cite journal
| title =Modulation of ATP-dependent chromatin-remodeling complexes by inositol polyphosphates
| journal = Science
| year = 2003
| volume = 299
| issue = 5603
| pages = 112–4
| pmid =12434013
| doi =10.1126/science.1078068
| author =Shen, X.
| last2 =Xiao
| first2 =H
| last3 =Ranallo
| first3 =R
| last4 =Wu
| first4 =WH
| last5 =Wu
| first5 =C }}</ref><ref>{{cite journal
| title = Regulation of chromatin remodelling by inositol polyphosphates
| journal = Science
| year = 2003
| volume = 299
| issue = 5603
| pages = 114–6
| pmid =12434012
| doi = 10.1126/science.1078062
| author = Steger, D. J.
| last2 = Haswell
| first2 = ES
| last3 = Miller
| first3 = AL
| last4 = Wente
| first4 = SR
| last5 = O'Shea
| first5 = EK
| pmc = 1458531 }}</ref>


=== Phytic acid in plants ===
=== Phytic acid in plants ===
[[Phytic acid]] (IP6 or phytate), a [[derivative (chemistry)|derivative]] of inositol with six phosphate groups, is the principal storage form of [[phosphorus]] in many [[plant]] [[Biological tissue|tissues]], especially [[bran]] and [[seed]].<ref name=phytochemicals>[http://www.phytochemicals.info/phytochemicals/phytic-acid.php Phytic acid]</ref> Neither the inositol nor the phosphate in phytic acid in plants is available to humans, or to animals that are not ruminants, since it cannot be broken down, except by bacteria. Moreover, phytic acid also chelates important minerals such as [[calcium]], [[magnesium]], [[iron]], and [[zinc]], making them unabsorbable, and contributing to mineral deficiencies in people whose diets rely highly on bran and seeds for their mineral intake, such as occurs in [[developing countries]].<ref>{{Cite journal|author=Hurrell RF |title=Influence of vegetable protein sources on trace element and mineral bioavailability |journal=The Journal of Nutrition |volume=133 |issue=9 |pages=2973S–7S |date=September 2003 |pmid=12949395 |url=http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=12949395}}</ref><ref>{{Cite book| chapter = Phytates | title = Toxicants Occurring Naturally in Foods | author = Committee on Food Protection | author2 = Food and Nutrition Board | author3 = National Research Council | publisher = National Academy of Sciences | year = 1973 | isbn = 978-0-309-02117-3 | pages = 363–371 | url = https://books.google.com/books?id=lIsrAAAAYAAJ&pg=PA363}}</ref>
[[Phytic acid]] (IP6 or phytate), a [[derivative (chemistry)|derivative]] of inositol with six phosphate groups, is the principal storage form of [[phosphorus]] in many [[plant]] [[Biological tissue|tissues]], especially [[bran]] and [[seed]].<ref name=phytochemicals>[http://www.phytochemicals.info/phytochemicals/phytic-acid.php Phytic acid]</ref> Neither the inositol nor the phosphate in phytic acid in plants is available to humans, or to animals that are not ruminants, since it cannot be broken down, except by bacteria. Moreover, phytic acid also chelates important minerals such as [[calcium]], [[magnesium]], [[iron]], and [[zinc]], making them unabsorbable, and contributing to mineral deficiencies in people whose diets rely highly on bran and seeds for their mineral intake, such as occurs in [[developing countries]].<ref>{{cite journal |vauthors=Hurrell RF |title=Influence of vegetable protein sources on trace element and mineral bioavailability |journal=The Journal of Nutrition |volume=133 |issue=9 |pages=2973S–7S |year=2003 |pmid=12949395 |url=http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=12949395 }}</ref><ref>{{Cite book| chapter = Phytates | title = Toxicants Occurring Naturally in Foods | author = Committee on Food Protection | author2 = Food and Nutrition Board | author3 = National Research Council | publisher = National Academy of Sciences | year = 1973 | isbn = 978-0-309-02117-3 | pages = 363–371 | url = https://books.google.com/books?id=lIsrAAAAYAAJ&pg=PA363}}</ref>


Inositol penta- (IP5), tetra- (IP4), and triphosphate (IP3) are also called "phytates".
Inositol penta- (IP5), tetra- (IP4), and triphosphate (IP3) are also called "phytates".
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== Counter to road salt ==
== Counter to road salt ==
When plants are exposed to increasing concentrations of [[road salt]], the plant cells become dysfunctional and undergo [[apoptosis]], leading to an inhibition of growth in plants. Inositol pretreatment could reverse the effects of salt on plants.<ref>{{cite journal|last1=Chaterjee|first1=J.|last2=Mujumder|first2=AL.|title=Salt-induced abnormalities on root tip mitotic cells of Allium cepa: prevention by inositol pretreatment.|date=September 2010|volume=245|issue=1-4|pages=165–72|doi=10.1007/s00709-010-0170-4|pmid=20559853|journal=Protoplasma}}</ref><ref>{{cite journal|last1=Theerakulpisut|first1=P.|last2=Gunnula|first2=W.|title=Exogenous Sorbitol and Trehalose Mitigated Salt Stress Damage in Salt-sensitive but not Salt-tolerant Rice Seedlings.|journal=Asian Journal of Crop Science|date=2012|volume=4|pages=165–170|doi=10.3923/ajcs.2012.165.170|url=http://scialert.net/abstract/?doi=ajcs.2012.165.170|accessdate=16 October 2014}}</ref>
When plants are exposed to increasing concentrations of [[road salt]], the plant cells become dysfunctional and undergo [[apoptosis]], leading to an inhibition of growth in plants. Inositol pretreatment could reverse the effects of salt on plants.<ref>{{cite journal |vauthors=Chatterjee J, Majumder AL |title=Salt-induced abnormalities on root tip mitotic cells of Allium cepa: prevention by inositol pretreatment |journal=Protoplasma |volume=245 |issue=1-4 |pages=165–72 |year=2010 |pmid=20559853 |doi=10.1007/s00709-010-0170-4 }}</ref><ref>{{cite journal |last1=Theerakulp |first1=P. |last2=Gunnula |first2=W. |title=Exogenous Sorbitol and Trehalose Mitigated Salt Stress Damage in Salt-sensitive but not Salt-tolerant Rice Seedlings |journal=Asian Journal of Crop Science |volume=4 |issue=4 |year=2012 |pages=165–70 |doi=10.3923/ajcs.2012.165.170 }}</ref>


== Research and clinical applications ==
== Research and clinical applications ==


Large doses of inositol have been studied for treatment of depression: the evidence is insufficient to determine whether inositol treatment can reduce depression symptoms, but no evidence of harm or negative side effects is seen.<ref>{{cite journal | vauthors =Taylor MJ, Wilder H, Bhagwagar Z, Geddes J | editor1-last=Taylor | editor1-first=Matthew J | title=Inositol for depressive disorders | journal=Cochrane Database Syst Rev | issue=2 | year=2004 | pages=CD004049 | pmid=15106232 | doi=10.1002/14651858.CD004049.pub2 }}</ref>
Large doses of inositol have been studied for treatment of depression: the evidence is insufficient to determine whether inositol treatment can reduce depression symptoms, but no evidence of harm or negative side effects is seen.<ref>{{cite journal |vauthors=Taylor MJ, Wilder H, Bhagwagar Z, Geddes J |title=Inositol for depressive disorders |journal=The Cochrane Database of Systematic Reviews |volume= |issue=2 |pages=CD004049 |year=2004 |pmid=15106232 |doi=10.1002/14651858.CD004049.pub2 }}</ref>


Inositol is effective in reducing adverse neonatal outcomes in preterm babies who either have or are at a risk of developing respiratory distress syndrome (RDS).<ref>{{Cite journal |vauthors=Howlett A, Ohlsson A, Plakkal N | title = Inositol in preterm infants at risk for or having respiratory distress syndrome. | journal = Cochrane Database Syst Rev | issue = 2 | pages = CD000366| year = 2015 | doi = 10.1002/14651858.CD000366.pub3}}</ref>
Inositol is effective in reducing adverse neonatal outcomes in preterm babies who either have or are at a risk of developing respiratory distress syndrome (RDS).<ref>{{cite journal |vauthors=Howlett A, Ohlsson A, Plakkal N |title=Inositol in preterm infants at risk for or having respiratory distress syndrome |journal=The Cochrane Database of Systematic Reviews |volume= |issue=2 |pages=CD000366 |year=2015 |pmid=25927089 |doi=10.1002/14651858.CD000366.pub3 }}</ref>


Inositol is considered a safe and effective treatment for PCOS. It works by reducing insulin sensitivity, improving ovarian function, and reducing hyperandrogenism<ref>https://www.ncbi.nlm.nih.gov/pubmed/27898267</ref>. It is also shown to reduce risk of metabolic disease <ref>https://www.ncbi.nlm.nih.gov/pubmed/22774396</ref>.
Inositol is considered a safe and effective treatment for PCOS. It works by reducing insulin sensitivity, improving ovarian function, and reducing hyperandrogenism.<ref>{{cite journal |vauthors=Monastra G, Unfer V, Harrath AH, Bizzarri M |title=Combining treatment with myo-inositol and D-chiro-inositol (40:1) is effective in restoring ovary function and metabolic balance in PCOS patients |journal=Gynecological Endocrinology |volume=33 |issue=1 |pages=1–9 |year=2017 |pmid=27898267 |doi=10.1080/09513590.2016.1247797 }}</ref> It is also shown to reduce risk of metabolic disease.<ref>{{cite journal |vauthors=Nordio M, Proietti E |title=The combined therapy with myo-inositol and D-chiro-inositol reduces the risk of metabolic disease in PCOS overweight patients compared to myo-inositol supplementation alone |journal=European Review for Medical and Pharmacological Sciences |volume=16 |issue=5 |pages=575–81 |year=2012 |pmid=22774396 }}</ref>


== Common use as a "cutting" agent ==
== Common use as a "cutting" agent ==
Inositol has been used as an adulterant (or [[cutting agent]]) in many illegal drugs, such as [[cocaine]], [[methamphetamine]], and sometimes [[heroin]].<ref>http://feedadditivechina.com/6-16-inositol.html</ref> This use is presumed to be connected with one or more of the substance's properties of solubility, powdery texture, or reduced [[sweetness]] (50%) as compared with more common sugars.
Inositol has been used as an adulterant (or [[cutting agent]]) in many illegal drugs, such as [[cocaine]], [[methamphetamine]], and sometimes [[heroin]].<ref>http://feedadditivechina.com/6-16-inositol.html{{full}}</ref> This use is presumed to be connected with one or more of the substance's properties of solubility, powdery texture, or reduced [[sweetness]] (50%) as compared with more common sugars.


Inositol is also used as a stand-in for cocaine on television and in film.<ref>{{cite web|last=Golianopoulos|first=Thomas|title=Drug Doubles: What Actors Actually Toke, Smoke and Snort on Camera|url=https://www.wired.com/underwire/2012/05/pl_drugs/|publisher=Wired Magazine|accessdate=14 May 2012}}</ref>
Inositol is also used as a stand-in for cocaine on television and in film.<ref>{{cite web|last=Golianopoulos|first=Thomas|title=Drug Doubles: What Actors Actually Toke, Smoke and Snort on Camera|url=https://www.wired.com/underwire/2012/05/pl_drugs/|publisher=Wired Magazine|accessdate=14 May 2012}}</ref>


== Nutritional sources ==
== Nutritional sources ==
''myo''-Inositol is naturally present in a variety of foods, although tables of this do not always distinguish between the bioavailable [[lecithin]] form, and the unavailable phytate form in grains.<ref name='foods'>{{cite journal|title=Myo-inositol content of common foods: development of a high-myo-inositol diet|journal=American Journal of Clinical Nutrition|year=1980|first1=Rex|last1=Clements |author2=Betty Darnell |volume=33 |issue=9 |pages=1954–1967 |pmid=7416064 |url=http://www.ajcn.org/cgi/reprint/33/9/1954.pdf|format=|accessdate=2009-05-18 }}</ref> According to research, foods containing the highest concentrations of ''myo''-inositol (including its compounds) include fruits, beans, grains, and nuts.<ref name='foods' /> Beans and grains, however, as seeds, contain large amounts of inositol as phytate.
''myo''-Inositol is naturally present in a variety of foods, although tables of this do not always distinguish between the bioavailable [[lecithin]] form, and the unavailable phytate form in grains.<ref name='foods'>{{cite journal |vauthors=Clements RS, Darnell B |title=Myo-inositol content of common foods: development of a high-myo-inositol diet |journal=The American Journal of Clinical Nutrition |volume=33 |issue=9 |pages=1954–67 |year=1980 |pmid=7416064 |url=http://www.ajcn.org/cgi/pmidlookup?view=long&pmid=7416064 }}</ref> According to research, foods containing the highest concentrations of ''myo''-inositol (including its compounds) include fruits, beans, grains, and nuts.<ref name='foods' /> Beans and grains, however, as seeds, contain large amounts of inositol as phytate.
Some energy drinks also contain inositol.
Some energy drinks also contain inositol.


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== External links ==
== External links ==
* [http://gmd.mpimp-golm.mpg.de/Spectrums/21bdad4b-931e-453b-aa3e-1824c658c2f0.aspx Inositol MS Spectrum]
* [http://gmd.mpimp-golm.mpg.de/Spectrums/21bdad4b-931e-453b-aa3e-1824c658c2f0.aspx Inositol MS Spectrum]
*{{cite journal |vauthors=Vucenik I, Shamsuddin AM |title=Cancer inhibition by inositol hexaphosphate (IP6) and inositol: from laboratory to clinic |journal=The Journal of Nutrition |volume=133 |issue=11 Suppl 1 |pages=3778S–3784S |year=2003 |pmid=14608114 |url=http://jn.nutrition.org/cgi/pmidlookup?view=long&pmid=14608114 }}
* [http://jn.nutrition.org/cgi/content/full/133/11/3778S ''Cancer Inhibition by Inositol Hexaphosphate (IP6) and Inositol: From Laboratory to Clinic'' (scientific publication)]
*{{cite journal |vauthors=Clements RS, Darnell B |title=Myo-inositol content of common foods: development of a high-myo-inositol diet |journal=The American Journal of Clinical Nutrition |volume=33 |issue=9 |pages=1954–67 |year=1980 |pmid=7416064 |url=http://www.ajcn.org/cgi/pmidlookup?view=long&pmid=7416064 }}
* [http://www.ajcn.org/cgi/reprint/33/9/1954.pdf ''Myo''-inositol Content of Various Foods]
* [http://druginfo.nlm.nih.gov/drugportal/dpdirect.jsp?name=Inositol U.S. National Library of Medicine: Drug Information Portal – Inositol]
* [http://druginfo.nlm.nih.gov/drugportal/dpdirect.jsp?name=Inositol U.S. National Library of Medicine: Drug Information Portal – Inositol]
* [http://www.ebi.ac.uk/pdbe-srv/PDBeXplore/ligand/?ligand=INS Inositol bound to proteins] in the [[Protein Data Bank|PDB]]
* [http://www.ebi.ac.uk/pdbe-srv/PDBeXplore/ligand/?ligand=INS Inositol bound to proteins] in the [[Protein Data Bank|PDB]]

Revision as of 13:01, 22 March 2017

myo-Inositol[1]
myo-Inositol
myo-Inositol
Names
IUPAC name
(1R,2R,3S,4S,5R,6S)-cyclohexane-1,2,3,4,5,6-hexol
Other names
cis-1,2,3,5-trans-4,6-Cyclohexanehexol , Cyclohexanehexol,
Mouse antialopecia factor,
Nucite, Phaseomannite,
Phaseomannitol,
Rat antispectacled eye
factor, and Scyllite
(for the structural
isomer scyllo-Inositol)
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.027.295 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C6H12O6/c7-1-2(8)4(10)6(12)5(11)3(1)9/h1-12H/t1-,2-,3-,4+,5-,6- checkY
    Key: CDAISMWEOUEBRE-GPIVLXJGSA-N checkY
  • InChI=1/C6H12O6/c7-1-2(8)4(10)6(12)5(11)3(1)9/h1-12H/t1-,2-,3-,4+,5-,6-
    Key: CDAISMWEOUEBRE-GPIVLXJGBG
  • [C@@H]1([C@@H]([C@@H]([C@@H]([C@H]([C@@H]1O)O)O)O)O)O
Properties
C6H12O6
Molar mass 180.16 g/mol
Density 1.752 g/cm3
Melting point 225 to 227 °C (437 to 441 °F; 498 to 500 K)
Pharmacology
A11HA07 (WHO)
Hazards
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 0: Will not burn. E.g. waterInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
0
0
Flash point 143 °C (289 °F; 416 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Inositol or cyclohexane-1,2,3,4,5,6-hexol is a chemical compound with formula Template:Carbon6Template:Hydrogen12Template:Oxygen6 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).[2][3] 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.[4] 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.[5] 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 (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-, D-chiro-, and neo-inositol. The other possible isomers are L-chiro-, 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.

myo- scyllo- muco- chiro-
neo- allo- epi- cis-

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.[6]

Biosynthesis

myo-Inositol is synthesized from glucose-6-phosphate (G-6-P) in two steps. First, G-6-P is isomerised by an inositol-3-phosphate synthase enzyme (for example, ISYNA1) to myo-inositol 1-phosphate, which is then dephosphorylated by an inositol monophosphatase enzyme (for example, IMPA1) to give free myo-inositol. In humans, most inositol is synthesized in the kidneys, in typical amounts of a few grams per day.[7]

Function

Inositol and some of its mono- and polyphosphates function as the basis for a number of signaling and secondary messenger molecules. They are involved in a number of biological processes, including:

Phytic acid in plants

Phytic acid (IP6 or phytate), a derivative of inositol with six phosphate groups, is the principal storage form of phosphorus in many plant tissues, especially bran and seed.[14] Neither the inositol nor the phosphate in phytic acid in plants is available to humans, or to animals that are not ruminants, since it cannot be broken down, except by bacteria. Moreover, phytic acid also chelates important minerals such as calcium, magnesium, iron, and zinc, making them unabsorbable, and contributing to mineral deficiencies in people whose diets rely highly on bran and seeds for their mineral intake, such as occurs in developing countries.[15][16]

Inositol penta- (IP5), tetra- (IP4), and triphosphate (IP3) are also called "phytates".

Use in explosives manufacture

At the 1936 meeting of the American Chemical Society, professor Edward Bartow of the University of Iowa presented a commercially viable means of extracting large amounts of inositol from the phytic acid naturally present in waste corn. As a possible use for the chemical, he suggested 'inositol nitrate' as a more stable alternative to nitroglycerin.[17] Today, inositol nitrate is used to gelatinize nitrocellulose, thus can be found in many modern explosives and solid rocket propellants.[18]

Counter to road salt

When plants are exposed to increasing concentrations of road salt, the plant cells become dysfunctional and undergo apoptosis, leading to an inhibition of growth in plants. Inositol pretreatment could reverse the effects of salt on plants.[19][20]

Research and clinical applications

Large doses of inositol have been studied for treatment of depression: the evidence is insufficient to determine whether inositol treatment can reduce depression symptoms, but no evidence of harm or negative side effects is seen.[21]

Inositol is effective in reducing adverse neonatal outcomes in preterm babies who either have or are at a risk of developing respiratory distress syndrome (RDS).[22]

Inositol is considered a safe and effective treatment for PCOS. It works by reducing insulin sensitivity, improving ovarian function, and reducing hyperandrogenism.[23] It is also shown to reduce risk of metabolic disease.[24]

Common use as a "cutting" agent

Inositol has been used as an adulterant (or cutting agent) in many illegal drugs, such as cocaine, methamphetamine, and sometimes heroin.[25] This use is presumed to be connected with one or more of the substance's properties of solubility, powdery texture, or reduced sweetness (50%) as compared with more common sugars.

Inositol is also used as a stand-in for cocaine on television and in film.[26]

Nutritional sources

myo-Inositol is naturally present in a variety of foods, although tables of this do not always distinguish between the bioavailable lecithin form, and the unavailable phytate form in grains.[27] According to research, foods containing the highest concentrations of myo-inositol (including its compounds) include fruits, beans, grains, and nuts.[27] Beans and grains, however, as seeds, contain large amounts of inositol as phytate. Some energy drinks also contain inositol.

See also

3

References

  1. ^ Merck Index, 11th Edition, 4883.
  2. ^ Synonyms in PubChem
  3. ^ Synonyms in Commonchemistry.org
  4. ^ Clements RS, Darnell B (1980). "Myo-inositol content of common foods: development of a high-myo-inositol diet". The American Journal of Clinical Nutrition. 33 (9): 1954–67. PMID 7416064.
  5. ^ Reynolds, James E. F. (January 1, 1993). Martindale: The Extra Pharmacopoeia. Vol. 30. Pennsylvania: Rittenhouse Book Distributors. p. 1379. ISBN 0-85369-300-5. An isomer of glucose that has traditionally been considered to be a B vitamin although it has an uncertain status as a vitamin and a deficiency syndrome has not been identified in man
  6. ^ S. M. N. Furse (2006). The Chemical and Bio-physical properties of Phosphatidylinositol phosphates (Thesis for M.Res.). Imperial College London.[page needed][unreliable source?]
  7. ^ Parthasarathy LK, Seelan RS, Tobias C, Casanova MF, Parthasarathy RN (2006). "Mammalian inositol 3-phosphate synthase: its role in the biosynthesis of brain inositol and its clinical use as a psychoactive agent". Sub-cellular Biochemistry. 39: 293–314. PMID 17121280.
  8. ^ Larner J (2002). "D-chiro-inositol--its functional role in insulin action and its deficit in insulin resistance". International Journal of Experimental Diabetes Research. 3 (1): 47–60. doi:10.1080/15604280212528. PMC 2478565. PMID 11900279.
  9. ^ Gerasimenko JV, Flowerdew SE, Voronina SG, Sukhomlin TK, Tepikin AV, Petersen OH, Gerasimenko OV (2006). "Bile acids induce Ca2+ release from both the endoplasmic reticulum and acidic intracellular calcium stores through activation of inositol trisphosphate receptors and ryanodine receptors". The Journal of Biological Chemistry. 281 (52): 40154–63. doi:10.1074/jbc.M606402200. PMID 17074764.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  10. ^ Kukuljan M, Vergara L, Stojilkovic SS (1997). "Modulation of the kinetics of inositol 1,4,5-trisphosphate-induced [Ca2+]i oscillations by calcium entry in pituitary gonadotrophs". Biophysical Journal. 72 (2 Pt 1): 698–707. Bibcode:1997BpJ....72..698K. doi:10.1016/S0006-3495(97)78706-X. PMC 1185595. PMID 9017197.
  11. ^ Rapiejko PJ, Northup JK, Evans T, Brown JE, Malbon CC (1986). "G-proteins of fat-cells. Role in hormonal regulation of intracellular inositol 1,4,5-trisphosphate". The Biochemical Journal. 240 (1): 35–40. PMC 1147372. PMID 3103610.
  12. ^ Shen X, Xiao H, Ranallo R, Wu WH, Wu C (2003). "Modulation of ATP-dependent chromatin-remodeling complexes by inositol polyphosphates". Science. 299 (5603): 112–4. doi:10.1126/science.1078068. PMID 12434013.
  13. ^ Steger DJ, Haswell ES, Miller AL, Wente SR, O'Shea EK (2003). "Regulation of chromatin remodeling by inositol polyphosphates". Science. 299 (5603): 114–6. doi:10.1126/science.1078062. PMC 1458531. PMID 12434012.
  14. ^ Phytic acid
  15. ^ Hurrell RF (2003). "Influence of vegetable protein sources on trace element and mineral bioavailability". The Journal of Nutrition. 133 (9): 2973S–7S. PMID 12949395.
  16. ^ Committee on Food Protection; Food and Nutrition Board; National Research Council (1973). "Phytates". Toxicants Occurring Naturally in Foods. National Academy of Sciences. pp. 363–371. ISBN 978-0-309-02117-3.
  17. ^ Laurence, William L. "Corn by-product yields explosive", The New York Times. April 17, 1936. Page 7.
  18. ^ Ledgard, Jared. The Preparatory Manual of Explosives, 2007. p. 366.
  19. ^ Chatterjee J, Majumder AL (2010). "Salt-induced abnormalities on root tip mitotic cells of Allium cepa: prevention by inositol pretreatment". Protoplasma. 245 (1–4): 165–72. doi:10.1007/s00709-010-0170-4. PMID 20559853.
  20. ^ Theerakulp, P.; Gunnula, W. (2012). "Exogenous Sorbitol and Trehalose Mitigated Salt Stress Damage in Salt-sensitive but not Salt-tolerant Rice Seedlings". Asian Journal of Crop Science. 4 (4): 165–70. doi:10.3923/ajcs.2012.165.170.
  21. ^ Taylor MJ, Wilder H, Bhagwagar Z, Geddes J (2004). "Inositol for depressive disorders". The Cochrane Database of Systematic Reviews (2): CD004049. doi:10.1002/14651858.CD004049.pub2. PMID 15106232.
  22. ^ Howlett A, Ohlsson A, Plakkal N (2015). "Inositol in preterm infants at risk for or having respiratory distress syndrome". The Cochrane Database of Systematic Reviews (2): CD000366. doi:10.1002/14651858.CD000366.pub3. PMID 25927089.
  23. ^ Monastra G, Unfer V, Harrath AH, Bizzarri M (2017). "Combining treatment with myo-inositol and D-chiro-inositol (40:1) is effective in restoring ovary function and metabolic balance in PCOS patients". Gynecological Endocrinology. 33 (1): 1–9. doi:10.1080/09513590.2016.1247797. PMID 27898267.
  24. ^ Nordio M, Proietti E (2012). "The combined therapy with myo-inositol and D-chiro-inositol reduces the risk of metabolic disease in PCOS overweight patients compared to myo-inositol supplementation alone". European Review for Medical and Pharmacological Sciences. 16 (5): 575–81. PMID 22774396.
  25. ^ http://feedadditivechina.com/6-16-inositol.html[full citation needed]
  26. ^ Golianopoulos, Thomas. "Drug Doubles: What Actors Actually Toke, Smoke and Snort on Camera". Wired Magazine. Retrieved 14 May 2012.
  27. ^ a b Clements RS, Darnell B (1980). "Myo-inositol content of common foods: development of a high-myo-inositol diet". The American Journal of Clinical Nutrition. 33 (9): 1954–67. PMID 7416064.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Inositol&oldid=771595205"