Trace amines

Phenethylamine (PEA) is an organic compound, natural monoamine alkaloid, and trace amine, which acts as a central nervous system stimulant in humans. In the brain, phenethylamine regulates monoamine neurotransmission by binding to trace amine-associated receptor 1 (TAAR1) and inhibiting vesicular monoamine transporter 2 (VMAT2) in monoamine neurons. To a lesser extent, it also acts as a neurotransmitter in the human central nervous system. In mammals, phenethylamine is produced from the amino acid L-phenylalanine by the enzyme aromatic L-amino acid decarboxylase via enzymatic decarboxylation.

Tryptamine, also known as 2-(3-indolyl)ethylamine, is an indolamine metabolite of the essential amino acid tryptophan. The chemical structure is defined by an indole—a fused benzene and pyrrole ring, and a 2-aminoethyl group at the second carbon (third aromatic atom, with the first one being the heterocyclic nitrogen). The structure of tryptamine is a shared feature of certain aminergic neuromodulators including melatonin, serotonin, bufotenin and psychedelic derivatives such as dimethyltryptamine (DMT), psilocybin, psilocin and others.

Tyramine ( ) (also spelled tyramin), also known under several other names, is a naturally occurring trace amine derived from the amino acid tyrosine. Tyramine acts as a catecholamine releasing agent. Notably, it is unable to cross the blood-brain barrier, resulting in only non-psychoactive peripheral sympathomimetic effects following ingestion. A hypertensive crisis can result, however, from ingestion of tyramine-rich foods in conjunction with the use of monoamine oxidase inhibitors (MAOIs).

Octopamine (OA), also known as '''para-octopamine and norsynephrine''' among synonyms, is an organic chemical closely related to norepinephrine, and synthesized biologically by a homologous pathway. Octopamine is often considered the major "fight-or-flight" neurohormone of invertebrates. Its name is derived from the fact that it was first identified in the salivary glands of the octopus.

Synephrine, or, more specifically, '''p-synephrine', is an alkaloid, occurring naturally in some plants and animals, and also in approved drugs products as its m-substituted analog known as neo-synephrine. p-Synephrine (or formerly Sympatol and oxedrine [BAN]) and m-synephrine are known for their longer acting adrenergic effects compared to epinephrine and norepinephrine. This substance is present at very low concentrations in common foodstuffs such as orange juice and other orange (Citrus species) products, both of the "sweet" and "bitter" variety. The preparations used in traditional Chinese

3-Methoxytyramine (3-MT), also known as 3-methoxy-4-hydroxyphenethylamine, is a human trace amine and the major metabolite of the monoamine neurotransmitter dopamine. It is formed by the introduction of a methyl group to dopamine by the enzyme catechol-O-methyltransferase (COMT). 3-MT can be further metabolized by the enzyme monoamine oxidase (MAO) to form homovanillic acid (HVA), which is then typically excreted in the urine.

Norfenefrine, also known as '''meta-octopamine or norphenylephrine and sold under the brand name Novadral' among others, is a sympathomimetic medication which is used in the treatment of hypotension (low blood pressure). Along with its structural isomer p''-octopamine and the tyramines, norfenefrine is a naturally occurring endogenous trace amine and plays a role as a minor neurotransmitter in the brain.

3-Iodothyronamine (T1AM) is an endogenous thyronamine. It is a high-affinity ligand of the trace amine-associated receptor 1 (TAAR1). T1AM is the most potent endogenous TAAR1 agonist yet discovered. It is also an agonist of the TAAR2 and TAAR5 with similar potency as for the TAAR1 (all in the case of the human proteins). T1AM is not a ligand of the thyroid hormone receptors. However, it is additionally a ligand of various monoamine and other receptors. For instance, it is a muscarinic acetylcholine receptor antagonist.

'''N-Methylphenethylamine (NMPEA''') is a naturally occurring trace amine neuromodulator in humans that is derived from the trace amine, phenethylamine (PEA). It has been detected in human urine (<1&nbsp;μg over 24&nbsp;hours) and is produced by phenylethanolamine N-methyltransferase with phenethylamine as a substrate, which significantly increases PEA's effects. PEA breaks down into phenylacetaldehyde which is further broken down into phenylacetic acid by monoamine oxidase. When this is inhibited by monoamine oxidase inhibitors, it allows more of the PEA to remain present and produce psychoac

'''N-Methyltyramine (NMT), also known as 4-hydroxy-N-methylphenethylamine', is a human trace amine and natural phenethylamine alkaloid found in a variety of plants. As the name implies, it is the N-methyl analog of tyramine, which is a well-known biogenic trace amine with which NMT shares many pharmacological properties. Biosynthetically, NMT is produced by the N-methylation of tyramine via the action of the enzyme phenylethanolamine N-methyltransferase in humans and tyramine N''-methyltransferase in plants.

Phenylethanolamine (sometimes abbreviated PEOH), or β-hydroxyphenethylamine, is a trace amine with a structure similar to those of other trace phenethylamines as well as the catecholamine neurotransmitters dopamine, norepinephrine, and epinephrine. As an organic compound, phenylethanolamine is a β-hydroxylated phenethylamine that is also structurally related to a number of synthetic drugs in the substituted phenethylamine class. In common with these compounds, phenylethanolamine has strong cardiovascular activity and, under the name Apophedrin, has been used as a drug to produce topical vasoco

amine receptors in the mammalian brain

'''meta-Tyramine, also known as m-tyramine and 3-tyramine, as well as 3-hydroxyphenethylamine', is an endogenous trace amine neuromodulator and a structural analog of phenethylamine. It is a positional isomer of para''-tyramine, and similarly to it, has effects on the adrenergic and dopaminergic systems.