Amino acids are converted to the respective amines by decarboxylation process. This is carried out by a group of enzymes called decarboxylase. The coenzyme involved in the reaction is PLP (pyridoxal phosphate). Biogenic amines, which have important functions, are synthesised by PLP decarboxylation.

Serotonin – Neurotransmitter regulates sleep, behaviour, and blood pressure.

Histamine – Vasodilator lowers BP, stimulates gastric HCl secretion, and involves in inflammation and allergic reactions.

GABA (γ-amino butyric acid) – Inhibitory neurotransmitter.

Catecholamines (dopamine, norepinephrine, and epinephrine) – Involved in metabolic and nervous regulations.