Trimethylamine N-oxide

Trimethylamine -N-oxide

Colorless to yellow, odorless solid

Fixed

• 213 ° C
• 95-99 ° C. (dihydrate )

Attention

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Trimethylamine oxide ( TMAO ), more trimethylamine N -oxide, is an amine oxide, that is, so to find a naturally occurring osmolyte in the cells of cartilaginous fish that live in salt water sharks, rays, and soft - as well as crustaceans. These animals use the substance to be iso-osmotic with sea water to need to store intracellularly without appropriate concentrations of soluble salt ions. By microbial degradation TMAO is to trimethylamine; this is the stuff that causes the typical smell of fish (see also occurrence of amines and smell of fish disease).

Stabilization of proteins against high hydrostatic pressure

Trimethylamine -N-oxide to stabilize proteins in cells of fish with respect to the hydrostatic pressure increasing with depth. So taking the average concentration of TMAO in genuine bony fish of 40 mmol / kg in 0 m depth to 261 mmol / kg at a depth of 4850 m. Thus, the internal osmolality rises in the fish cells with increasing habitat depth. The fastest TMAO concentration was measured with 386 mmol / kg in target belly fish Notoliparis kermadecensis in depth 7000 m in Kermadecgraben, which corresponds to an osmolality of 991 mOsmol / kg. This means that fish below a depth of 8200 m can not live, because in this case the osmolality of seawater 1100 mOsmol / kg is achieved, which can not be exceeded, because otherwise the sea water would flow into the cells.

Freezing point depression of proteins

Trimethylamine -N-oxide takes in some Antarctic and Arctic teleost fish, the function of an antifreeze. Due to high concentrations of up to 1.4 mol / l, it makes a significant contribution to lowering the freezing point of body fluids.