Biological activity

Many kinds of biological activity produce amines by breakdown of amino acids. Many natural neurotransmitters like epinephrine, norepinephrine, dopamine, serotonine, histamine are amines.

Application of amines

Dyes

Primary aromatic amines are used as a starting material for the manufacture of azo dyes. It reacts with nitric(III) acid to form diazonium salt, which can undergo coupling reaction to form azo compound. As azo-compounds are highly coloured, they are widely used in dyeing industries, such as:

• Methyl orange
• Direct brown 138
• Sunset yellow FCF
• Ponceau

Drugs

Many drugs are designed to mimic or to interfere with the action of natural amine neurotransmitters, exemplified by the amine drugs:

• Chlorpheniramine is an antihistamine that helps to relieve allergic disorders due to cold, hay fever, itchy skin, insect bites and stings.
• Chlorpromazine is a tranquillizer that sedates without inducing sleep. It is used to relieve anxiety, excitement, restlessness or even mental disorder.
• Ephedrine and Phenylephrine, as amine hydrochlorides, are used as decongestants.
• Amphetamine, Methamphetamine, and Methcathinone are amines that are listed as controlled substances by the DEA.
• Amitriptyline, Imipramine, Lofepramine and Clomipramine are tricyclic antidepressants and tertiary amines
• Nortriptyline, Desipramine, and Amoxapine are tricyclic antidepressants and secondary amines
• (The tricyclics are grouped by the nature of the final amine group on the side chain.)

Gas treatment

• Aqueous monoethanolamine (MEA), diglycolamine (DGA), diethanolamine (DEA), diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) are widely used industrially for removing carbon dioxide (CO₂) and hydrogen sulfide (H₂S) from natural gas streams and refinery process streams. They may also be used to remove CO₂ from combustion gases / flue gases and may have potential for abatement of greenhouse gases.

Safety

Low molecular weight amines are toxic and some are easily absorbed through the skin. Many higher molecular weight amines are highly active biologically.