Odor trimethylamine

Many low molecular weight amines have very foul odors. Trimethylamine [(CH3)3N], formed when enzymes break down certain fish proteins, has the characteristic odor of rotting fish. Putrescine (NH2CH2CH2CH2CH2NH2) and cadaverine (NH2CH2CH2CH2CH2CH2NH2) are both poisonous diamines with putrid odors. They, too, are present in rotting fish, and are partly responsible for the odors of semen, urine, and bad breath. 

Amines occur widely in all living organisms. Trimethylamine, for instance, occurs in animal tissues and is partially responsible for the distinctive odor of fish, nicotine is found in tobacco, and cocaine is a stimulant found in the South American coca bush. In addition, amino acids are the buildingblocks from which all proteins are made, and cyclic amine bases are constituents of nucleic acids. 

In addition to their role in chemical defense, DMSP-lyase products may also function as chemical cue in more complex trophic cascades. In the natural environment DMS-production is related to zooplankton herbivory [60] and can thus act as an indicator for the availability of food for planktivorous birds. Indeed, some Antarctic Procellariiform seabirds can detect DMS (22) and are highly attracted to the cue, as was shown with DMS-scented oil slicks on the ocean surface [61]. The odors released during zooplankton grazing (DMS) as well as those of zooplankton itself (e.g., trimethylamine and pyrazines) are attractive to birds [62], thus assisting vertebrate search behavior. 

Another experiment used cod liver oil, crude krill extract, and the krill odor components trimethylamine and pyrazine, with phenylethanol (rose odor) as control. Several procellariiform species were attracted to krill extract. The krill odor components attracted giant petrels, cape petrels, blue petrels, Antarctic petrels, Kerguelen petrels, and black-browed albatrosses. Cape petrels were more attracted to trimethylamine than to pyrazine and cod liver oil hut blue petrels responded most to cod liver oil (Nevitt, 1999). 

Another chemical method for measuring freshness, that is more rapid, continuous, and less destructive than other methods is the detection of volatile trimethylamine (TMA), dimethylamine (DMA), monomethylamine (MMA), and ammonia 14,15). Trimethylamine oxide (TMAO) is a decomposition product of proteins as well as present in excretions of fish 16). Spoilage bacteria can reduce TMAO to TMA plus small amounts of DMA, MMA, and ammonia. Tissue TMA levels have be correlated with the pungent odor associated with spoiled seafood as well as total bacterial counts 14). Researchers incorporated a test strip... 

Sulfur trioxide reactivity can also be moderated through the use of S03 adducts. The reactivity of such complexes is inversely proportional to their stability, and consequendy they can be selected for a wide variety of conditions. Whereas moderating S03 reactivity by adducting agents is generally beneficial, the agents add cost and may contribute to odor and possible toxicity problems in derived products. Cellulosic material has been sulfated with SCT—trimethylamine adduct in aqueous media at 0 to 5°C (16). Sulfur trioxide—triethyl phosphate has been used to sulfonate alkenes to the corresponding alkene sulfonate (17). Sulfur trioxide—pyridine adduct sulfates oleyl alcohol with no attack of the double bond (18). 

There is also a genetic deficiency in FM03 in humans leading to Fish Odor syndrome, which results from the inability of the afflicted individuals to metabolism trimethylamine, which has a strong fishy smell, to the N-oxide, which has no smell. 

Polyurethanes (PU) The odor of many polyurethanes is caused by fishy smelling low molecular weight amines, mostly methylamines like trimethylamine, degradation products of the amine catalysts used during production. In some cases after evaporation of the fishy smelling amines, other odor qualities remain. One noticeable odor of PU samples was earthy, nutty, which can often be attributed to substituted pyrazines, formed by condensation of two a-aminoketones, subsequent oxidation or alkylation by aldehydes. One example is 2-ethyl-3,5-dimethylpyrazine (Mayer and Breuer, 2006). 

Salts and organic by-products, mostly the diol resulting from hydrolysis of the epoxide, from dry cationization are left in the starch. Trimethylamine, if formed, can be detected by its odor. It can be neutralized by subsequent addition of acid. Addition of a slightly soluble organic acid, such as fumaric or adipic acid, during the cationization both eliminates the odor and aids scale control in starch cooking equipment.44... 

There are a number of similarities between ammonia and amines that carry beyond the structure. Consider odor. The smell of amines resembles that of ammonia but is not as sharp. However, amines can be quite pungent. Anyone handling or working with raw fish knows how strong the amine odor can be, since raw fish contains low-molecular-weight amines such as dimethylamine and trimethylamine. Other amines associated with decaying flesh have names suggestive of their odors putrescine and cadaverine. 

The decomposition of hypaphorine into indole and trimethylamine occurs slowly in the rotting wood of Abrus precatorius L., and is responsible for its fecal odor. It also led van Romburgh (30) to propose the correct structure for hypaphorine, which was soon established by synthesis from L-tryptophan (17). 

The amines are derivatives of ammonia, NH., obtained by replacing one or more of the hydrogen atoms by organic radicals. The lighter amines, such as methylaihine, CH NIL., dimethylamine, (CH3)oNH, and trimethylamine, (CH3)3N, are gases. Trimethylamine has a pronounced fishy odor, and many other amines also have disagreeable odors. 

A mixture of 100 ml. of aqueous 33% trimethylamine solution and 600 ml. of 3% hydrogen peroxide is allowed to stand for 24 hours. If the odor of the amine is still apparent, another 100-200 ml. of hydrogen peroxide is added. After the amine odor has disappeared, the mixture is evaporated under vacuum and the residue is recrystallized from ethanol-ether mixture. The yield of trimethylamine oxide di-hydrate, m.p. 96°, is aroimd 95%. 

To 2 ml of trimethylamine (33 per cent solution) add 13 ml of 3 per cent hydrogen peroxide. Cork, and let stand until the next laboratory period. Note whether any odor of amine remains. Evaporate to dryness on a water bath, and add 2 ml of alcohol. The crystals which separate out are the hydrate of trimethylamine oxide, (CH3)3N0-2 H O. 

Another characteristic of amines is their odor. Low-molecular-we amines such as trimethylamine have a distinctive fishlike aroma, whil diamines such as cadaverine (1,5-pentanediamine) have names that are self-explanatory. 

Properties White, crystalline powder odorless or faint trimethylamine-like odor acidic taste. Hygroscopic soluble in water and alcohol insoluble in ether, chloroform, and benzene. 

F.) has an ammoniacal odor, and is quite soluble in H,0. It constitutes about 50 per cent of the coimnercial trimethylamine, which also contains 5 to 10 per cent of triinethylaiuine, the remainder being a mixture of monomeiliylamine, isobutylamine, and propylamine. Its chloi o-platinate forms long needles. 

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