phenylethylamiinien

Phenylethylamines are a broad class of organic compounds characterized by a phenyl group attached to an ethylamine chain (the basic structure is C6H5-CH2-CH2-NH2). The family includes endogenous biogenic amines as well as many synthetic derivatives. They range from simple trace amines found in small amounts in the body to substituted phenethylamines that act as psychoactive drugs.

In humans, phenylethylamine itself is produced in small quantities from L-phenylalanine by the enzyme aromatic L-amino acid decarboxylase. It functions as a trace amine that can modulate monoaminergic transmission, in part via interactions with the TAAR1 receptor. Phenylethylamines are rapidly metabolized by monoamine oxidases, particularly MAO-B, which results in a short duration of action for endogenous compounds.

Substituted phenylethylamines form a diverse subset with a wide range of pharmacological effects. Some derivatives act as monoamine releasing agents or receptor agonists, influencing dopamine, norepinephrine, and serotonin systems. Well-known examples include amphetamine and methamphetamine (alpha-methylphenethylamines) and 3,4-methylenedioxylphenethylamines such as MDMA. These compounds are subjects of extensive pharmacological and toxicological research due to their stimulant and psychoactive properties. Endogenous phenylethylamines may play roles in mood, attention, and appetite regulation, though their precise physiological significance remains under study.

Occurrence in nature is generally limited, and while phenylethylamines occur in small amounts in foods (for example, chocolate contains trace levels of phenylethylamine), dietary intake is unlikely to produce marked pharmacological effects due to rapid metabolism.

See also: trace amines; monoamine neurotransmitters; phenylalanine.