Carboline

β-Carboline

Names
IUPAC name 9H-β-carboline
Other names 9H-pyrido[3,4-b]indole
Identifiers
CAS Number	244-63-3 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:109895 Y
ChemSpider	58486 Y
ECHA InfoCard	100.005.418
IUPHAR/BPS	8222
MeSH	norharman
PubChem CID	64961
InChI InChI=1S/C11H8N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-7,13H Y Key: AIFRHYZBTHREPW-UHFFFAOYSA-N Y InChI=1/C11H8N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-7,13H Key: AIFRHYZBTHREPW-UHFFFAOYAG
SMILES c2cncc3nc1ccccc1c23
Properties
Chemical formula	C11H8N2
Molar mass	168.20 g/mol
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

β-Carboline (9H-pyrido[3,4-b]indole), also known as norharmane, is a nitrogen containing heterocycle. It is also the prototype of a class of compounds known as β-carbolines.

β-Carboline alkaloids are widespread in plants and animals, and frequently act as benzodiazepine inverse agonists. As components of the liana Banisteriopsis caapi, the β-carbolines harmine, harmaline, and tetrahydroharmine play a pivotal role in the pharmacology of the indigenous psychedelic drug ayahuasca by preventing the breakdown of dimethyltryptamine in the gut by reversibly inhibiting monoamine oxidase, thus making it psychoactive upon oral administration. Some β-carbolines, notably tryptoline and pinoline, may be formed naturally in the human body. The latter is possibly implicated along with melatonin in the role of the pineal gland in regulating the sleep-wake cycle. β-carboline is a benzodiazepine receptor inverse agonist and can therefore have convulsive, anxiogenic and memory enhancing effects. 9-methyl-β-carbolines appear to induce DNA damage when exposed to ultra-violet light.

β-Carboline belongs to the group of indole alkaloids and consist of pyridine ring that is fused to an indole skeleton. The structure of β-carboline is similar to that of tryptamine, with the ethylamine chain re-connected to the indole ring via an extra carbon atom, to produce a three-ringed structure. The biosynthesis of β-carbolines is believed to follow this route from analogous tryptamines. Different levels of saturation are possible in the third ring, which is indicated here in the structural formula by colouring the optionally double bonds red and blue: