5-Hydroxytryptamines

Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, memory, and physiological processes such as vomiting and vasoconstriction. In the CNS, serotonin regulates mood, appetite, and sleep.

Bufotenin, also known as dimethylserotonin or as '5-hydroxy-N,N-dimethyltryptamine (5-HO-DMT'), is a serotonergic psychedelic of the tryptamine family. It is a derivative of the psychedelic dimethyltryptamine (DMT) and of the neurotransmitter serotonin (5-hydroxytryptamine; 5-HT). The compound is an alkaloid found in some species of mushrooms, plants, and toads. It is also found naturally in the human body in small amounts. Bufotenin, for instance derived from the trees Anadenanthera colubrina and Anadenanthera peregrina, has a long history of entheogenic use as a snuff in South America.

5-Hydroxytryptophan (5-HTP), used medically as oxitriptan, is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitter serotonin.

'''N-Acetylserotonin (NAS), also known as normelatonin''', is a naturally occurring chemical intermediate in the endogenous production of melatonin from serotonin. It also has biological activity in its own right, including acting as a melatonin receptor agonist, an agonist of the TrkB, and having antioxidant effects.

5,7-Dihydroxytryptamine (5,7-DHT) is a monoaminergic neurotoxin used in scientific research to decrease concentrations of serotonin in the brain. The mechanism behind this effect is not well understood, but it is speculated to selectively destroy serotonergic neurons, in a manner similar to the dopaminergic neurotoxicity of 6-hydroxydopamine (6-OHDA). What is known is that this compound is in fact not selective in depleting serotonin content, but also depletes norepinephrine. To selectively deplete serotonin stores, it is commonly administered in conjunction with desmethylimipramine (desiprami

Desoxyfructo-serotonin is a leprostatic agent.

Bufothionine is a sulfur-containing compound which is present in the bufotoxins secreted by the parotoid gland of certain toads of the genera Bufo and Chaunus. The structure has been shown by X-ray crystallography to be (1,3,4,5-tetrahydro-5,5-dimethylpyrrolo-[4,3,2-de]quinolinio)-6-sulfate. This specific compound can be found in the skin of certain species of toad such as the Asiatic Toad, Chaunus arunco, Chaunus crucifer, Chaunus spinulosus, and Chaunus arenarum.

Noribogaine, also known as '''O-desmethylibogaine or 12-hydroxyibogamine', is the principal psychoactive metabolite of the oneirogen ibogaine. It is thought to be involved in the antiaddictive effects of ibogaine-containing plant extracts, such as Tabernanthe iboga''.

'''N-Methylserotonin, also known as norbufotenin or as 5-hydroxy-N-methyltryptamine (5-HO-NMT'), is a tryptamine alkaloid. Chemically, it is a derivative of serotonin in which a methyl group resides at its alkyl amine. It is also called Nω-methylserotonin (N''ω-methyl-5-hydroxytryptamine) to distinguish it from tryptamine-derived compounds in which a methyl group is bonded to the nitrogen atom of the indole group.

α-Methylserotonin (αMS), also known as α-methyl-5-hydroxytryptamine (α-methyl-5-HT) or as 5-hydroxy-α-methyltryptamine (5-HO-αMT), is a tryptamine derivative closely related to the neurotransmitter serotonin (5-HT). It acts as a non-selective serotonin receptor agonist and has been used extensively in scientific research to study the function of the serotonin system.

5-HO-DiPT, also known as '5-hydroxy-N,N-di-iso-propyltryptamine', is a tryptamine derivative which acts as a serotonin receptor agonist. It is primarily known as a metabolite of the better known psychoactive drug 5-MeO-DiPT, but 5-HO-DiPT has also rarely been encountered as a designer drug in its own right. Tests in vitro show 5-HO-DiPT to have high serotonin 5-HT2A receptor affinity and good selectivity over the serotonin 5-HT1A receptor, while being more lipophilic than the related drug bufotenine (5-HO-DMT), which produces primarily peripheral effects.

2-Methyl-5-hydroxytryptamine (2-methylserotonin, 2-methyl-5-HT) is a tryptamine derivative closely related to the neurotransmitter serotonin which acts as a moderately selective full agonist at the 5-HT3 receptor.