Substances biogenic

Fig. 1 Fluorescence scan of a chromatogram track with a mixture of biogenic amines with 1 ng substance per chromatogram zone 1 = histamine, 2 = serotonin, 3 = tyramine, 4 = phenylethylamine.

Hymenoptera venoms are composed of biogenic amines and other low molecular weight substances, of basic peptides and of proteins. Injection of venom by Hymenoptera stings has toxic effects, due to biogenic amines, peptides and proteins biogenic amines such as histamine cause pain, are vasodilatory and increase... 

Air, water, soil, and food are all unavoidable components of the human environment. Each of those elements influences the quality of human life, and each of them may be contaminated. Food is not only the elementary source of nutrients, but may also contain natural chemical substances with toxic properties, e.g., cyanogenic glycosides (many plants), solanine (green parts of potatoes, sprouted potatoes, and potatoes stored in light), industrial pollutants (heavy metals), biogenic amines (fish), or mycotoxins (moldy foodstuffs). 

Several amino acids are broken down by de-carbo qflation. This reaction gives rise to what are known as biogenic amines, which have various functions. Some of them are components of biomolecules, such as ethanolamine in phospholipids (see p. 50). Cysteamine and T-alanine are components of coenzyme A (see p.l2) and of pantetheine (see pp. 108, 168). Other amines function as signaling substances. An important neurotransmitter derived from glutamate is y-aminobutyrate (GABA, see p.356). The transmitter dopamine is also a precursor for the catecholamines epinephrine and norepinephrine (see p.352). The biogenic amine serotonin, a substance that has many effects, is synthesized from tryptophan via the intermediate 5-hydroxytryptophan. 

The proteinogenic amino acid glutamate (Glu) and the biogenic amine 4-aminobuty-rate derived from it are among the most important neurotransmitters in the brain (see p. 352). They are both synthesized in the brain itself In addition to the neurons, which use Glu or GABA as transmitters, neuroglia are also involved in the metabolism of these substances. 

There are more than 10 billion neurons that make up the human nervous system, and they interact with one another through neurotransmitters. Acetylcholine, a number of biogenic amines (norepinephrine, dopamine, serotonin, and in all likelihood, histamine and norepinephrine), certain amino acids and peptides, and adenosine are neurotransmitters in the central nervous system. Amino acid neurotransmitters are glutamic and aspartic acids that excite postsynaptic membrane receptors of several neurons as well as y-aminobutyric acid (GABA) and glycine, which are inhibitory neurotransmitters. Endorphins, enkephalins, and substance P are considered peptidergic transmitters. There are many compounds that imitate the action of these neurotransmitters. 

A number of criteria could be apphed to organize this chapter, depending on the point of view by which foods are considered. In this chapter, application of HPLC to food analysis will be described considering homogeneous classes of food components lipids, carbohydrates and related substances, proteins, peptides, amino acids, biogenic amines, phenolics, vitamins, and some selected contaminants. 

S-Adenosyl-l-methionine (SAMe) is a naturally occurring substance whose primary role appears to be that of a methyl donor in the CNS ( 252). It participates in the metabolism of various biogenic amines implicated in the pathogenesis of depressive disorders. Several investigations have indicated that it may be an effective antidepressant with minimal adverse effects. 

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