Saturday, 27 July 2013

AMINES Part 1 - An Introduction

Cross Sensitivity

A sensitivity to one substance that predisposes an individual to sensitivity to other substances that are related in chemical structure. Cross sensitivity with allergic reactions may develop between antibiotics of similar chemical structures.
Mosby's Medical Dictionary, 8th edition. 2009, Elsevier

The Penicillin and Cephalosporin antibiotics are cousins. Some people who are allergic to Penicillin may react to antibiotics from the Cephalosporin group.

Thus, it is the same where natural compounds in food are concerned. I have already touched on salicylates and phenols in food.

To read more about salicylate, click on LINK.
To read more about phenols, click on LINK.

What Are Amines?

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair.

Amines are derivatives of ammonia where one or more of the hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group.

*Alkyl - In organic chemistry, an alkane is a saturated hydrocarbon. This means it only consists of hydrogen and carbon atoms, all bonds are single bonds and the carbon atoms are not joined in a cyclic structure but are in an open chain. An alkyl group is like an alkane consists mostly of single-bonded carbon and hydrogen atom.

*Aryl - An aryl is substituent derived from an aromatic ring (aromatic hydrocarbon).

There are some amines which we come across in our daily lives. They are amino acids, biogenic amines, trimethylamine and aniline.

1. Amino Acids

One of the main uses of amino acids in the industry is animal feed. The amino acids are added as an additive as the main bulk of these feeds are made from soybeans (which are naturally low/or may lack of some essential amino acids). Lysine, methionine, threonine and tryptophan are the most important amino acids in the production of these feeds.

You may question of the importance of adding these to the feeds. There are amino acids which are essential to humankind. They are 9 of them. They are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine. They are labelled as 'essential' because our bodies do not produce them. Thus, we need to have an intake of these 'essential' amino acids.

There are also non-essential amino acids. They are alanine, arginine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serene, tyrosine, asparagine and selenocysteine. They are only essential in certain cases. An example would be the need for cysteine, tyrosine and arginine which are required by infants and growing children. We fully grown adults do not need them.

The food industry is another major amino acid user. The glutamic acid and aspartame are two of the most widely used amino acid in the food industry. Glutamic acid is used as a flavour enhancer. Aspartame is a low-calorie artificial sweetener.

The third industry which uses amino acids is the agriculture industry. The chelating of amino acids are used in fertilizers to provide minerals to plants which have mineral deficiencies. An example would be iron chlorosis. Thus, by providing them the necessary minerals, mineral deficiencies would be reduced and the overall health of the crops would be boosted.

2. Biogenic Amines

A biogenic amine is biogenic substance with one or more amine groups. A biogenic substance is a substance which is produced by life processes. It could be secreted or is a part of plants and animals.

Examples of biogenic amines are:

a. Histamine

This is a substance which is derived from the amino acid histidine which acts as a neurotransmitter mediating arousal and attention. It is also a pro-inflammatory signal released from mast cells in response to allergic reactions or tissue damage.

Histamine is also an important stimulant of HCl (hydrochloric acid) secretion by the stomach through the histamine H2 receptors.

b. Serotonin

This is a central nervous system neurotransmitter derived from the amino acid tryptophan. Its role is to regulate mood, sleep, appetite and sexuality.

c. Catecholamine neurotransmitters

There are three of this neurotransmitters:

  • Norepinephrine - This is a neurotransmitter which is involved in sleep and wakefulness, attention, feeding behaviour and a stress hormone that regulates the sympathetic nervous system.
  • Epinephrine - This is an adrenal stress hormone.
  • Dopamine - This is a neurotransmitter that is involved in motivation, reward, addiction, behavioral reinforcement and coordination of body movements.
d. Trace Amines

  • 3-Iodothyronamine - This is a metabolite of the thyroid hormones.
  • Tryptarmine - This is a monoamine alkaloid found in the brains of mammals. It acts as a neuromodulator and neurotransmitter.
  • Tyramine - This is a substance found in many types of common food which causes migraines, headaches and elevated blood pressure.
  • Dimethyltryptamine (DMT)
  • Phenethylamine
  • Octopamine

3. Trimethylamine

Trimethylamine is an organic compound which is colorless, hydroscopic and a flammable tertiary amine. It has a strong 'fishy' odour in low concentrations. At higher concentrations, it has an amonia-like odour.

Trimethylamine is a product of decomposition of plants and animals. It is associated with roting fish, some infections, bad breath and is also capable of causing the vaginal odour due to bacterial vaginosis.

Trimethylaminuria is a genetic disorder where the body is unable to metabolize trimethylamine from food sources. People with this genetic disorder develope a characteristic fish odour in their sweat, urine and breath after consuming choline-rich foods.

4. Aniline

This is an organic compound with a phenyl group attached to an amino group. This means it is an aromatic amine. It has the odour of rotten fish! It also ignites easily. Its main use is in the manufacture of precursors to polyurethane.

Aniline is used in rubber processing chemicals, herbicides, dyes and pigments.

Aniline was used as an analgesic drug in the late 19th century. Paracetamol is a drug prepared from aniline.

It is also used in the dye industry which is known as azo dyes.


  1. Sorry Girl!
    You lost me there!
    I failed Chemistry....