Tryptoline

Names

Preferred IUPAC name 2,3,4,9-Tetrahydro-1H-pyrido[3,4-b]indole

Other names Noreleagnine; Tetrahydronorharman; THN; 2,3,4,9-Tetrahydro-1H-β-carboline; 1,2,3,4-Tetrahydro-β-carboline; Tetrahydro-β-carboline; THβC; THBC

Identifiers

CAS NumberY

3D model (JSmol)

ChEMBLY

ChemSpiderY

ECHA InfoCard

PubChem CID

UNIIY

CompTox Dashboard (EPA)

InChI InChI=1S/C11H12N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-4,12-13H,5-7H2YKey: CFTOTSJVQRFXOF-UHFFFAOYSA-NYInChI=1/C11H12N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-4,12-13H,5-7H2Key: CFTOTSJVQRFXOF-UHFFFAOYAW

SMILES c1ccc2c(c1)c3c([nH]2)CNCC3

Properties

Chemical formulaC11H12N2

Molar mass172.226 g/mol

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Tryptoline, also known as 1,2,3,4-tetrahydro-β-carboline (THβC) and tetrahydronorharmane (THN), is a natural organic derivative of β-carboline. It is an alkaloid chemically related to tryptamines. Derivatives of tryptoline have a variety of pharmacological properties and are known collectively as tryptolines.

Use and effects

The properties and effects of tryptoline in humans do not appear to be known.

Pharmacology

Pharmacodynamics

Tryptolines are competitive selective inhibitors of the enzyme monoamine oxidase type A (MAO-A). 5-Hydroxytryptoline and 5-methoxytryptoline are the most active monoamine oxidase inhibitors (MAOIs) with IC50 values of 500nM and 1,500nM, respectively.

Tryptolines are also potent reuptake inhibitors of serotonin and epinephrine, with a significantly greater selectivity for serotonin.

In-vivo formation of tryptolines has been a matter of controversy.

Tryptoline shows weak affinity for the serotonin 5-HT1A and 5-HT2A receptors (Ki = 2,510nM and 3,900nM, respectively). However, it showed a high affinity (Ki) of 28nM against tryptamine-labeled binding sites, whereas affinity for serotonin- and spiperone-labeled sites were much lower (Ki = 6,030nM and 12,030nM, respectively). The drug shows substantially lower affinity for serotonin receptors than tryptamine. Tryptoline is 60-fold more potent in terms of tryptamine binding site interaction than its serotonin reuptake inhibition. The drug is inactive as an agonist of the serotonin 5-HT2B receptor in the rat fundus stomach strip (KB = >3,000nM).

Tryptoline is known to produce various behavioral effects in animals, including analgesia, hypothermia, and hypophagia, as well as antidopaminergic-like reversal of behavioral effects of apomorphine such as hyperlocomotion.

Chemistry

Derivatives

Tryptoline derivatives have been found to interact with serotonin receptors, such as the serotonin 5-HT1A and 5-HT2 receptors. A couple of notable derivatives, 1-ethyl-6-hydroxytryptoline and 1-(2,4,5-trimethoxyphenyl)-6-chlorotryptoline, are potent and high-efficacy agonists of the serotonin 5-HT2 receptors, including of the serotonin 5-HT2A receptor.