Trimethylamine N-oxide

Trimethylamine N-oxide
IUPAC name

trimethylamine oxide
Preferred IUPAC name

N,N-dimethylmethanamine oxide
Other names

trimethylamine oxide, TMAO, TMANO
Identifiers
CAS number 1184-78-7 Y
PubChem 1145
ChemSpider 1113 Y
UNII FLD0K1SJ1A Y
KEGG C01104 Y
ChEBI CHEBI:15724 Y
Jmol-3D images Image 1
Properties
Molecular formula C3H9NO
Molar mass 75.11 g mol−1
Appearance colourless solid
Melting point

220–222 °C (hydrate: 96 °C)
Solubility in water good
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Trimethylamine N-oxide, also known by several other names and acronyms, is the organic compound with the formula (CH3)3NO. This colorless solid is usually encountered as the dihydrate. It is an oxidation product of trimethylamine and a common metabolite in animals. It is an osmolyte found in saltwater fish, sharks and rays, molluscs, and crustaceans. It is a protein stabilizer that may serve to counteract urea, the major osmolyte of sharks, skates and rays. It is also higher in deep-sea fishes and crustaceans, where it may counteract the protein-destabilizing effects of pressure. [1]TMAO decomposes to trimethylamine (TMA), which is the main odorant that is characteristic of degrading seafood.

Contents

Synthesis

Treatment of aqueous trimethylamine with hydrogen peroxide affords the dihydrate (Me = CH3):[2]

H2O2 + Me3N → H2O + Me3NO

Trimethylamine-N-oxide is biosynthesized from trimethylamine, which is derived from choline.[3]

Trimethylaminuria

Main article: Trimethylaminuria

Trimethylaminuria is a defect in the production of the enzyme flavin containing monooxygenase 3 (FMO3),[4][5], causing incomplete breakdown of trimethylamine from choline-containing food into trimethylamine oxide. Trimethylamine then builds up and is released in the person's sweat, urine, and breath, giving off a strong fishy odor.

Laboratory applications

Trimethylamine oxide is used in protein folding experiments to counteract the unfolding effects of urea.[6]

In organometallic chemistry, Me3NO is employed as a decarbonylation agent according to the following stoichiometry:

M(CO)n + Me3NO + L → M(CO)n-1L + Me3N + CO2

This reaction is used to decomplex organic ligands from metals, e.g. from (diene)Fe(CO)3.[2]

It is used in certain oxidation reactions, e.g. the conversion of alkyl iodides to the aldehyde.[7]

References

  1. ^ Yancey, P. (2005). "Organic osmolytes as compatible, metabolic, and counteracting cytoprotectants in high osmolarity and other stresses". J. Exp. Biol. 208 (15): 2819–2830. doi:10.1242/jeb.01730. PMID 16043587. 
  2. ^ a b A. J. Pearson "Trimethylamine N-Oxide" in Encyclopedia of Reagents for Organic Synthesis John Wiley & Sons, 2001: New York. doi:10.1002/047084289X.rt268
  3. ^ Baker, J.R.; Chaykin, S. (1 April 1962). "The biosynthesis of trimethylamine-N-oxide". J. Biol. Chem. 237 (4): 1309–13. PMID 13864146. http://www.jbc.org/cgi/content/citation/237/4/1309. 
  4. ^ Treacy, E.P.; Akerman, BR et al. (1998). "Mutations of the flavin-containing monooxygenase gene (FMO3) cause trimethylaminuria, a defect in detoxication". Human Molecular Genetics 7 (5): 839–45. doi:10.1093/hmg/7.5.839. PMID 9536088. 
  5. ^ Zschocke J, Kohlmueller D, Quak E, Meissner T, Hoffmann GF, Mayatepek E (1999). "Mild trimethylaminuria caused by common variants in FMO3 gene". Lancet 354 (9181): 834–5. doi:10.1016/S0140-6736(99)80019-1. PMID 10485731. 
  6. ^ Zou, Q. et al. (2002). "The Molecular Mechanism of Stabilization of Proteins by TMAO and Its Ability to Counteract the Effects of Urea". J. Am. Chem. Soc. 124 (7): 1192–1202. doi:10.1021/ja004206b. PMID 11841287. 
  7. ^ Volker Franzen (1973), "Octanal", Org. Synth., http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv5p0872 ; Coll. Vol. 5: 872