Tryptoline

Tryptoline, also known as tetrahydro-β-carboline and tetrahydronorharmane, is a natural organic derivative of beta-carboline. It is an alkaloid chemically related to tryptamines. Derivatives of tryptoline have a variety of pharmacological properties and are known collectively as tryptolines.

Tryptoline

Names
IUPAC name 1,2,3,4-Tetrahydro-9H-pyrido[3,4-b]indole
Other names Noreleagnine Tetrahydronorharman 2,3,4,9-Tetrahydro-1H-β-carboline
Identifiers
CAS Number	16502-01-5^Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL269236^Y
ChemSpider	96979^Y
ECHA InfoCard	100.156.194
PubChem CID	107838
UNII	65027TMI0H^Y
CompTox Dashboard (EPA)	DTXSID10167835
InChI InChI=1S/C11H12N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-4,12-13H,5-7H2^Y Key: CFTOTSJVQRFXOF-UHFFFAOYSA-N^Y InChI=1/C11H12N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-4,12-13H,5-7H2 Key: CFTOTSJVQRFXOF-UHFFFAOYAW
SMILES c1ccc2c(c1)c3c([nH]2)CNCC3
Properties
Chemical formula	C11H12N2
Molar mass	172.226 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Pharmacology

Many tryptolines are competitive selective inhibitors of the enzyme monoamine oxidase type A (MAO-A). 5-Hydroxytryptoline and 5-methoxytryptoline (pinoline) are the most active monoamine oxidase inhibitors (MAOIs) with IC₅₀s of 0.5 μM and 1.5 μM respectively, using 5-hydroxytryptamine (serotonin) as substrate.

Tryptolines are also potent reuptake inhibitors of serotonin and epinephrine, with a significantly greater selectivity for serotonin. Comparison of the inhibition kinetics of tetrahydro-β-carbolines for serotonin and epinephrine reuptake to that of the platelet aggregation response to these amines has shown that 5-hydroxymethtryptoline, methtryptoline, and tryptoline are poor inhibitors of reuptake. In all respects 5-hydroxytryptoline and 5-methoxytryptoline showed greater pharmacological activity than the tryptoline and methtryptoline.

Although the in vivo formation of tryptolines has been a matter of controversy, they have profound pharmacological activity.

See also

• Norharmane
• harmane
• beta-Carboline
• Harmala alkaloid

References

• H. Rommelspacher; H. Kauffmann; C. Heyck Cohnitz; H. Coper (1977). "Pharmacological properties of tetrahydronorharmane (Tryptoline)". Journal Naunyn-Schmiedeberg's Archives of Pharmacology. 298 (2): 83–91. doi:10.1007/BF00508615.