Definition and meaning of Phenethylamine

Phenethylamine

Systematic (IUPAC) name
phenylethan-2-amine
Clinical data
Pregnancy cat.	?
Legal status	Uncontrolled
Routes	Oral
Pharmacokinetic data
Metabolism	MAO-A, MAO-B, ALDH, DBH, CYP2D6
Half-life	~5-10 minutes
Identifiers
CAS number	64-04-0 Y
ATC code	?
PubChem	CID 1001
IUPHAR ligand	2144
ChemSpider	13856352 Y
UNII	327C7L2BXQ Y
ChEBI	CHEBI:18397 Y
ChEMBL	CHEMBL610 Y
NIAID ChemDB	018561
Synonyms	2-phenylethylamine, β-phenylethylamine, 1-amino-2-phenylethane
Chemical data
Formula	C8H11N
Mol. mass	121.18 g/mol
SMILES c1ccc(cc1)CCN
InChI InChI=1S/C8H11N/c9-7-6-8-4-2-1-3-5-8/h1-5H,6-7,9H2 Y Key:BHHGXPLMPWCGHP-UHFFFAOYSA-N Y
Y (what is this?)  (verify)

Phenylethylamine or phenethylamine (PEA) is a natural monoamine alkaloid, a trace amine, and also the name of a class of chemicals with many members well known for psychoactive drug and stimulant effects.^[1] Studies^[2] suggest that phenylethylamine functions as a neuromodulator or neurotransmitter in the mammalian central nervous system. It is biosynthesized from the amino acid phenylalanine by enzymatic decarboxylation. In addition to mammals, phenethylamine is found in many other organisms and foods such as chocolate, especially after microbial fermentation. It is sold as a dietary supplement for purported mood and weight loss-related therapeutic benefits; however, orally ingested phenethylamine is usually inactive because of extensive first-pass metabolism by monoamine oxidase (MAO) into phenylacetic acid. This prevents significant concentrations from reaching the brain.^[3][4]

The group of phenethylamine derivatives is referred to as the phenethylamines. Substituted phenethylamines, substituted amphetamines, and substituted methylenedioxyphenethylamines (MDxx) are a series of broad and diverse classes of compounds derived from phenethylamine that include stimulants, psychedelics, and entactogens, as well as anorectics, bronchodilators, decongestants, and antidepressants, among others.

  Chemistry

Phenethylamine is a primary amine, the amino-group being attached to a benzene ring through a two-carbon, or ethyl group. It is a colorless liquid at room temperature. Phenethylamine is soluble in water, ethanol, and ether. Similar to other low-molecular-weight amines, it has a fishy odor. Upon exposure to air, it forms a solid carbonate salt with carbon dioxide. Phenethylamine is strongly basic, pK_b = 4.17 (or pK_a = 9.83), as measured using the HCl salt,^[5]and forms a stable crystalline hydrochloride salt with a melting point of 217 °C. Phenethylamine is also a skin irritant and possible sensitizer.

Phenethylamine has an inactive constitutional isomer 1-phenylethylamine, which itself has two stereoisomers: (R)-(+)-1-phenylethylamine and (S)-(-)-1-phenylethylamine.

  Pharmacology

Phenethylamine, similar to amphetamine in its action, releases norepinephrine and dopamine.^[6][7][8] However, when taken orally it is rapidly metabolized.^[9]

Abnormally low concentrations of endogenous phenethylamine are found in those suffering from attention-deficit hyperactivity disorder (ADHD)^[10] and often in clinical depression^{[citation needed]}, whereas abnormally high concentrations have been discovered to have a strong, positive correlation with the incidence of schizophrenia.^[11]

  Pharmacokinetics

Phenylethylamine's half-life is 5–10 minutes.^[12] Phenylethylamine is metabolized by MAO-A,^[4] MAO-B,^[3] aldehyde dehydrogenase, and dopamine-beta-hydroxylase.^[12] When initial phenylethylamine brain concentration are low, phenylethylamine brain levels can be increased by a 1000-fold when taking a MAO Inhibitor, and by 3-4 times when the initial concentration are high. ^[13]}

  Chocolate theory of love

In the early 1980s, researcher Michael Liebowitz, author of the popular 1983 book The Chemistry of Love, remarked to reporters that "chocolate is loaded with PEA." This became the focus for an article in The New York Times, which was then taken up by the wire services and then by magazine free-lancers, evolving into the now-eponymous "chocolate theory of love."^[14] However, as noted earlier, phenethylamine is rapidly metabolized by the enzyme MAO-B, preventing significant concentrations from reaching the brain, thus contributing no perceptible psychoactive effect without the use of a monoamine oxidase inhibitor (MAOI).

  See also

• Trace amines
• 1-Phenylethylamine
• Amphetamine
• Alexander Shulgin
• PiHKAL
• Substituted phenethylamine

  References

  External links

• Book II of PiHKAL online
• Phenethylamine entry in PiHKAL • info
• Review and summary of PiHKAL, including table of 300+ phenethylamines: ascii postscript
• A Structural Tour of PiHKAL