Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. This colorless, hygroscopic, and flammable tertiary amine has a strong "fishy" odor in low concentrations and an ammonia-like odor at higher concentrations. It is a gas at room temperature but is usually sold in pressurized gas cylinders or as a 40% solution in water. TMA is a nitrogenous base and can be readily protonated to give trimethylammonium cation. Trimethylammonium chloride is a hygroscopic colorless solid prepared from hydrochloric acid. Trimethylamine is a good nucleophile, and this reaction is the basis of most of its applications.
|Preferred IUPAC name
(Trimethyl)amine (The name trimethylamine is deprecated.)
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||59.112 g·mol−1|
|Density||670 kg m−3 (at 0 °C)|
627.0 kg m−3 (at 25 °C)
|Melting point||−117.20 °C; −178.96 °F; 155.95 K|
|Boiling point||3 to 7 °C; 37 to 44 °F; 276 to 280 K|
|Vapor pressure||188.7 kPa (at 20 °C)|
|95 μmol Pa−1 kg−1|
Std enthalpy of
|−24.5 to −23.0 kJ mol−1|
|GHS signal word||DANGER|
|H220, H315, H318, H332, H335|
|P210, P261, P280, P305+351+338|
|Flash point||−7 °C (19 °F; 266 K)|
|190 °C (374 °F; 463 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|500 mg kg−1 (oral, rat)|
|US health exposure limits (NIOSH):|
|TWA 10 ppm (24 mg/m3) ST 15 ppm (36 mg/m3)|
IDLH (Immediate danger)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Trimethylamine is a product of decomposition of plants and animals. In humans, it is synthesized exclusively by gut microbiota from dietary nutrients such as choline and carnitine. High levels of trimethylamine are associated with the development of fish odor syndrome, which arise from the foul, fishy odor of trimethylamine. TMA is the substance mainly responsible for the odor often associated with rotting fish, some infections, bad breath and can be a cause of vaginal odor due to bacterial vaginosis. It is also associated with taking large doses of choline and carnitine.
In 2013, trimethylamine was identified as a potent full agonist of human TAAR5, a trace amine-associated receptor that is expressed in the olfactory epithelium and functions as an olfactory receptor for tertiary amines. One or more additional odorant receptors appear to be involved in trimethylamine olfaction in humans as well.
- 3 CH3OH + NH3 → (CH3)3N + 3 H2O
- 9 (CH2=O)n + 2n NH4Cl → 2n (CH3)3N•HCl + 3n H2O + 3n CO2↑
Trimethylamine is used in the synthesis of choline, tetramethylammonium hydroxide, plant growth regulators or herbicides, strongly basic anion exchange resins, dye leveling agents and a number of basic dyes. Gas sensors to test for fish freshness detect trimethylamine.
Trimethylaminuria is an autosomal recessive genetic 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.
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- Falony G, Vieira-Silva S, Raes J (2015). "Microbiology Meets Big Data: The Case of Gut Microbiota-Derived Trimethylamine". Annu. Rev. Microbiol. 69: 305–321. doi:10.1146/annurev-micro-091014-104422. PMID 26274026.
we review literature on trimethylamine (TMA), a microbiota-generated metabolite linked to atherosclerosis development.
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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.
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- Zhang J, Pacifico R, Cawley D, Feinstein P, Bozza T (February 2013). "Ultrasensitive detection of amines by a trace amine-associated receptor". J. Neurosci. 33 (7): 3228–39. doi:10.1523/JNEUROSCI.4299-12.2013. PMC 3711460. PMID 23407976.
We show that [human TAAR5] responds to the tertiary amine N,N-dimethylethylamine and to a lesser extent to trimethylamine, a structurally related agonist for mouse and rat TAAR5 (Liberles and Buck, 2006; Staubert et al., 2010; Ferrero et al., 2012).
- Zhang LS, Davies SS (April 2016). "Microbial metabolism of dietary components to bioactive metabolites: opportunities for new therapeutic interventions". Genome Med. 8 (1): 46. doi:10.1186/s13073-016-0296-x. PMC 4840492. PMID 27102537.
Table 2: Microbial metabolites: their synthesis, mechanisms of action, and effects on health and disease
Figure 1: Molecular mechanisms of action of indole and its metabolites on host physiology and disease
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- 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. doi:10.1002/jsfa.2740300809.
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