indoleamine

Indoleamines are a class of bioactive organic compounds that contain an indole ring bonded to an amino group. They are typically derived from the amino acid tryptophan and include physiologically important molecules such as serotonin (5-hydroxytryptamine) and melatonin, as well as various tryptamines like tryptamine and N,N-dimethyltryptamine, along with related metabolites. They occur in animals, plants, and microbes and can serve signaling roles beyond metabolism.

In animals, serotonin is synthesized from tryptophan by first hydroxylating to 5-hydroxytryptophan and then decarboxylating to serotonin. Melatonin is produced from serotonin through acetylation and methylation. In other organisms, indoleamines may be produced via alternative pathways and participate in signaling networks that respond to environmental or physiological cues.

Functions of indoleamines are diverse. Many act as neurotransmitters or neuromodulators, with serotonin influencing mood, appetite, and gut function, and melatonin regulating circadian rhythms and sleep. They can also function as hormones in peripheral tissues. In plants and microbes, indoleamines contribute to signaling processes and stress responses, influencing growth, defense, and adaptation.

Medical and pharmacological notes: dysregulation of indoleamine signaling has been associated with mood disorders, sleep disturbances, and circadian rhythm disorders. Some indoleamines, particularly certain tryptamines, have psychoactive properties and are studied for their effects on perception and cognition; these compounds are subject to regulatory controls in many jurisdictions.