Trimethylamine N-oxide
Trimethylamine N-oxide is an organic compound with the formula. It is in the class of amine oxides. Although the anhydrous compound is known, trimethylamine N-oxide is usually encountered as the dihydrate. Both the anhydrous and hydrated materials are white, water-soluble solids.
TMAO is found in the tissues of marine crustaceans and marine fish, where it prevents water pressure from distorting proteins and thus killing the animal. The concentration of TMAO increases with the depth at which the animal lives; TMAO is found in high concentrations in the deepest-living described fish species, Pseudoliparis swirei, which was found in the Mariana Trench, at a recorded depth of.
In animals, TMAO is a product of the oxidation of trimethylamine, a common metabolite of trimethyl quaternary ammonium compounds, like choline, trimethylglycine, and L-carnitine. High TMAO concentrations are associated with an increased risk of all-cause mortality and cardiovascular disease.
Marine animals
Trimethylamine N-oxide is an osmolyte found in molluscs, crustaceans, and all marine fishes and bony fishes. It is a protein stabilizer that serves to counteract the protein-destabilizing effects of pressure. In general, the bodies of animals living at great depths are adapted to high pressure environments by having pressure-resistant biomolecules and small organic molecules present in their cells, known as piezolytes, of which TMAO is the most abundant. These piezolytes give the proteins the flexibility they need to function properly under great pressure.TMAO decomposes to trimethylamine, which is the main odorant that is characteristic of degrading seafood.
TMAO in diet
TMAO levels increase with consumption of animal protein such as eggs, red meat, shellfish and total fish consumption. Plant-based diets such as vegan, vegetarian and the Mediterranean diet lower TMAO levels.Chemistry
TMAO can be synthesized from trimethylamine by treatment with hydrogen peroxide:The dihydrate is dehydrated by azeotropic distillation from dimethylformamide.
Laboratory applications
Trimethylamine oxide is used in protein folding experiments to counteract the unfolding effects of urea.In the organometallic chemistry reaction of nucleophilic abstraction, is employed as a decarbonylation agent according to the following stoichiometry:
where M is a metal. This reaction is used to decomplex organic ligands from metals, e.g. from.
It is used in certain oxidation reactions, e.g. the conversion of alkyl iodides to the corresponding aldehyde.