4-Hydroxytryptamine

4-Hydroxytryptamine
Clinical data
Other names4-HT; 4-HTA; N,N-Didesmethylpsilocin; Dinorpsilocin
Drug classSerotonin receptor agonist; Non-hallucinogenic serotonin 5-HT2A receptor agonist
Identifiers
  • 3-(2-aminoethyl)-1H-indol-4-ol
CAS Number
PubChem CID
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
Chemical and physical data
FormulaC10H12N2O
Molar mass176.219 g·mol−1
3D model (JSmol)
  • C1=CC2=C(C(=C1)O)C(=CN2)CCN
  • InChI=1S/C10H12N2O/c11-5-4-7-6-12-8-2-1-3-9(13)10(7)8/h1-3,6,12-13H,4-5,11H2
  • Key:FKIRTWDHOWAQGX-UHFFFAOYSA-N

4-Hydroxytryptamine (4-HT, 4-HTA), also known as N,N-didesmethylpsilocin, is a naturally occurring tryptamine alkaloid.[1][2][3] It is a positional isomer of serotonin (5-hydroxytryptamine; 5-HT) and is the dephosphorylated form of norbaeocystin.[4] The compound may serve as an alternative precursor of psilocybin in psilocybin mushrooms.[1][5][2]

4-HT is a potent agonist of the serotonin 5-HT2A receptor similarly to psilocin.[3] It is centrally penetrant.[3] Surprisingly however, the compound, similarly to baeocystin, norbaeocystin, and norpsilocin, does not produce the head-twitch response, a behavioral proxy of psychedelic effects, in animals, and hence is putatively non-hallucinogenic.[3][6] In older literature, the psychoactive effects of 4-hydroxylated tryptamines have been said to increase in the series of 4-hydroxytryptamine, 4-hydroxy-N-methyltryptamine (norpsilocin), and 4-hydroxy-N,N-dimethyltryptamine (psilocin).[2] The reason for the lack of hallucinogenic effects with 4-HT and related compounds is unknown, but may be due to biased agonism of the serotonin 5-HT2A receptor; or, more specifically, biased agonism for the β-arrestin2 signaling pathway.[3]

Norbaeocystin is thought to be a prodrug of 4-HT, analogously to how psilocybin is a prodrug of psilocin and how baeocystin is thought to be a prodrug of norpsilocin.[7][3]

4-Hydroxytryptamine was first described in the scientific literature by 1959.[8][9] Its pharmacology was first thoroughly characterized in 2024.[3]

  1. ^ a b Wieczorek PP, Witkowska D, Jasicka-Misiak I, Poliwoda A, Oterman M, Zielińska K (2015). "Bioactive Alkaloids of Hallucinogenic Mushrooms". Studies in Natural Products Chemistry. Vol. 46. Elsevier. pp. 133–168. doi:10.1016/b978-0-444-63462-7.00005-1. ISBN 978-0-444-63462-7. ISSN 1572-5995.
  2. ^ a b c Wurst M, Kysilka R, Flieger M (2002). "Psychoactive tryptamines from basidiomycetes". Folia Microbiologica. 47 (1): 3–27. doi:10.1007/BF02818560. PMID 11980266.
  3. ^ a b c d e f g Rakoczy RJ, Runge GN, Sen AK, Sandoval O, Wells HG, Nguyen Q, et al. (October 2024). "Pharmacological and behavioural effects of tryptamines present in psilocybin-containing mushrooms". British Journal of Pharmacology. 181 (19): 3627–3641. doi:10.1111/bph.16466. PMID 38825326.
  4. ^ "4-Hydroxytryptamine". PubChem. Retrieved 28 October 2024.
  5. ^ Irvine W, Tyler M, Delgoda R (June 2023). "In silico characterization of the psilocybin biosynthesis pathway". Computational Biology and Chemistry. 104: 107854. doi:10.1016/j.compbiolchem.2023.107854. PMID 36990027.
  6. ^ Sherwood AM, Halberstadt AL, Klein AK, McCorvy JD, Kaylo KW, Kargbo RB, et al. (February 2020). "Synthesis and Biological Evaluation of Tryptamines Found in Hallucinogenic Mushrooms: Norbaeocystin, Baeocystin, Norpsilocin, and Aeruginascin". Journal of Natural Products. 83 (2): 461–467. doi:10.1021/acs.jnatprod.9b01061. PMID 32077284.
  7. ^ Lowe H, Toyang N, Steele B, Valentine H, Grant J, Ali A, et al. (May 2021). "The Therapeutic Potential of Psilocybin". Molecules. 26 (10): 2948. doi:10.3390/molecules26102948. PMC 8156539. PMID 34063505.
  8. ^ Vane JR (March 1959). "The relative activities of some tryptamine analogues on the isolated rat stomach strip preparation". British Journal of Pharmacology and Chemotherapy. 14 (1): 87–98. doi:10.1111/j.1476-5381.1959.tb00933.x. PMC 1481817. PMID 13651584.
  9. ^ Erspamer V, Glasser A, Mantegazzini P (November 1960). "Pharmacological actions of 4-hydroxytryptamine and 4-hydroxytryptophan". Experientia. 16 (11): 505–506. doi:10.1007/BF02158367. PMID 13697285.