Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a trimethylated derivative of ammonia. TMA is widely used in industry.[5][6] At higher concentrations it has an ammonia-like odor, and can cause necrosisofmucous membranes on contact.[7] At lower concentrations, it has a "fishy" odor, the odor associated with rotting fish.
TMA protonates to give the trimethylammonium cation. Trimethylamine is a good nucleophile, and this reactivity underpins most of its applications. Trimethylamine is a Lewis base that forms adducts with a variety of Lewis acids.[8]
In humans, ingestion of certain plant and animal (e.g., red meat, egg yolk) food containing lecithin, choline, and L-carnitine provides certain gut microbiota with the substrate to synthesize TMA, which is then absorbed into the bloodstream.[11][12] High levels of trimethylamine in the body are associated with the development of trimethylaminuria, or fish odor syndrome, caused by a genetic defect in the enzyme which degrades TMA; or by taking large doses of supplements containing cholineorL-carnitine.[11][12] TMA is metabolized by the liver to trimethylamine N-oxide (TMAO); TMAO is being investigated as a possible proatherogenic substance which may accelerate atherosclerosis in those eating foods with a high content of TMA precursors.[12] TMA also causes the odor of some human infections, bad breath, and bacterial vaginosis.
Acute and chronic toxic effects of TMA were suggested in medical literature as early as the 19th century. TMA causes eye and skin irritation, and it is suggested to be a uremic toxin.[17] In patients, trimethylamine caused stomach ache, vomiting, diarrhoea, lacrimation, greying of the skin and agitation.[18] Apart from that, reproductive/developmental toxicity has been reported.[7] Some experimental studies suggested that TMA may be involved in etiology of cardiovascular diseases.[19][20]
Trimethylaminuria is an autosomalrecessivegenetic disorder involving a defect in the function or expression of flavin-containing monooxygenase 3 (FMO3) which results in poor trimethylamine metabolism. Individuals with trimethylaminuria develop a characteristic fish odor—the smell of trimethylamine—in their sweat, urine, and breath after the consumption of choline-rich foods. A condition similar to trimethylaminuria has also been observed in a certain breed of Rhode Island Red chicken that produces eggs with a fishy smell, especially after eating food containing a high proportion of rapeseed.[22][23]
The first dream of his own which Sigmund Freud tried to analyse in detail, when he was developing his theories about the interpretation of dreams, involved a patient of Freud's who had to have an injection of trimethylamine, and the chemical formula of the substance, written in bold letters on the bottle, jumping out at Freud.[24]
^Swift, Elijah; Hochanadel, Helen Phillips (May 1945). "The Vapor Pressure of Trimethylamine from 0 to 40°". Journal of the American Chemical Society. 67 (5): 880–881. doi:10.1021/ja01221a508.
^ abAshford, Robert D. (2011). Ashford's Dictionary of Industrial Chemicals (3rd ed.). Wavelength. p. 9362. ISBN978-0-9522674-3-0.
^ ab"Trimethylamine [MAK Value Documentation, 1983]", The MAK-Collection for Occupational Health and Safety, Wiley-VCH Verlag GmbH & Co. KGaA, 27 October 2014, pp. 1–9, doi:10.1002/3527600418.mb7550e0914, ISBN978-3527600410
^Cramer, R. E.; Bopp, T. T. (1977). "Graphical display of the enthalpies of adduct formation for Lewis acids and bases". Journal of Chemical Education. 54: 612–613. doi:10.1021/ed054p612.
^Adams, Roger; Marvel, C. S. (1921). "Trimethylamine Hydrochloride". Organic Syntheses. 1: 79. doi:10.15227/orgsyn.001.0079.
^ abcGaci N, Borrel G, Tottey W, O'Toole PW, Brugère JF (November 2014). "Archaea and the human gut: new beginning of an old story". World J. Gastroenterol. 20 (43): 16062–16078. doi:10.3748/wjg.v20.i43.16062. PMC4239492. PMID25473158. Trimethylamine is exclusively a microbiota-derived product of nutrients (lecithin, choline, TMAO, L-carnitine) from normal diet, from which seems originate two diseases, trimethylaminuria (or Fish-Odor Syndrome) and cardiovascular disease through the proatherogenic property of its oxidized liver-derived form.
^Wills, M. R.; Savory, J. (1981). "Biochemistry of renal failure". Annals of Clinical and Laboratory Science. 11 (4): 292–9. PMID7023344.
^"Gifte und Vergiftungen. Vierte Ausgabe des Lehrbuches der Toxikologie. Von Prof. Louis Lewin. Mit 41 Figuren und einer farbigen Spektraltafel. Berlin 1929. Verlag von Georg Stilke. 1087 Seiten. Preis geh. 50,— Mark, geb. 55,— Mark". Archiv der Pharmazie. 267 (4): 322–323. 1929. doi:10.1002/ardp.19292670410. ISSN0365-6233. S2CID221459303.
^Pearson, Arthur W.; Butler, Edward J.; Curtis, R. Frank; Fenwick, G. Roger; Hobson-Frohock, Anthony; Land, Derek G. (1979). "Effect of rapeseed meal on trimethylamine metabolism in the domestic fowl in relation to egg taint". Journal of the Science of Food and Agriculture. 30 (8): 799–804. Bibcode:1979JSFA...30..799P. doi:10.1002/jsfa.2740300809.
† References for all endogenous human TAAR1 ligands are provided at List of trace amines
‡ References for synthetic TAAR1 agonists can be found at TAAR1 or in the associated compound articles. For TAAR2 and TAAR5 agonists and inverse agonists, see TAAR for references.
