Organic substances of interest because of their possible role in brain functioning; subdivided into catecholamines (e.g., tyrosine, phenylalanine, dopamine, epinephrine, norepinephrine) and indoleamines (e.g., tryptophan, serotonin).
The biosynthetic pathway for the catecholamines is tyrosine → dihydroxyphenylalanine → dopamine → norepinephrine → epinephrine.
The biosynthetic pathway for the indoleamines is tryptophan → serotonin (5-hydroxytryptamine) → 5-hiaa (5-hydroxyindoleacetic acid).
Formed in the body by decarboxylation of amino acids. They can be found in food plants. Large dietary intakes of foods containing these amines can pose some risk of harm. Biogenic amines in food can originate from fermentation of that food or from bacterial contamination. The main producers of biogenic amines in foods are Enterobacteriaceae and Enterococci. Examples of biogenic amines include ethylamine (precursor: alanine), putrescine (precursor: ornithine), histamine (pre¬ cursor: histidine), cadaverine (precursor: lysine), tyramine (precursor: tyrosine), phenylethylamine (precursor: phenylalanine), and tryptamine (precursor: tryptophan). Symptoms of biogenic amine intoxication, persisting for several hours, include burning throat, flushing, headache, nausea, hypertension, numbness, and tingling of the lips, rapid pulse, and vomiting. Factors stimulating the formation of biogenic amines include the following: presence of free amino acids, acting as precursors; low pH of the product; high NaCl concentration; and microbial decarboxylase activity. Occurrence of biogenic amines has been reported in lactate-fermented products, in particular wine, cheese, fish, and meat, and in fermented vegetables. Natural occurrences of biogenic amines (produced by microbial decarboxylase activity) have been reported in fruits, vegetables, and fish. Pasteurization of cheese and milk, good hygienic practices, and selection of bacterial cultures having low decarboxylase activity can prevent the accumulation of biogenic amines.
A group of chemical compounds, most of which are important in neurotransmission. Included are norepinephrine, histamine, serotonin, and dopamine.