indolamine

Indolamine is a class of chemical compounds that combine an indole nucleus with an amine group. The core indole ring is a bicyclic structure consisting of a six‑membered benzene ring fused to a five‑membered pyrrole ring. In indolamines, the indole is linked to a side chain bearing an amine group, typically at the 3‑position, and various substitutions yield diverse compounds. Many indolamines are derived from the amino acid tryptophan, through enzymatic decarboxylation and subsequent modifications.

Natural occurrence: Endogenous indolamines include serotonin (5‑hydroxytryptamine), a key neurotransmitter in the nervous system, and melatonin (N‑acetyl‑5‑hydroxytryptamine), a hormone involved in circadian regulation. The tryptamine subclass, comprising compounds such as tryptamine, N,N‑dimethyltryptamine (DMT), and related derivatives, occurs in a range of plants, fungi, and animals and is notable for pharmacological activity.

Biosynthesis and metabolism: In humans and other animals, serotonin is synthesized from tryptophan via hydroxylation to 5‑hydroxytryptophan followed by decarboxylation. Melatonin is produced from serotonin through acetylation and methylation. In plants, microbes, and some animals, tryptamine derivatives are produced by decarboxylation of tryptophan and subsequent enzymatic steps.

Functions and applications: Indolamines serve as neurotransmitters, neuromodulators, hormones, or intermediates in biosynthetic pathways. They are studied in neuroscience and pharmacology, and synthetic tryptamines are used in research, with some compounds also known for psychoactive properties.

See also: Indole; Tryptamine; Serotonin; Melatonin.