{{Short description|Group of chemical compounds}} {{Lowercase title}} {{Distinguish|Substituted β-carboline}} {{Chembox | Name = β-Carboline | verifiedrevid = 443419704 | ImageFile=beta-Carboline.svg | ImageClass = skin-invert-image | ImageFile2=Β-Carboline.png | ImageClass2 = bg-transparent | ImageAlt2=Chemical structure of β-carboline | PIN=9''H''-Pyrido[3,4-''b'']indole | OtherNames={{ubl|Norharmane|Norharman|Carbazoline|2-Azacarbazole|2,9-Diazafluorene}} |Section1={{Chembox Identifiers | IUPHAR_ligand = 8222 | InChIKey = AIFRHYZBTHREPW-UHFFFAOYAG | Beilstein = 128414 | ChEMBL_Ref = {{ebicite|correct|EBI}} | ChEMBL = 275224 | EC_number = 205-959-0 | KEGG = C20157 | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChI = 1S/C11H8N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-7,13H | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = AIFRHYZBTHREPW-UHFFFAOYSA-N | CASNo_Ref = {{cascite|correct|CAS}} | CASNo=244-63-3 | UNII_Ref = {{fdacite|correct|FDA}} | UNII = 94HMA1I78O | PubChem=64961 | ChEBI_Ref = {{ebicite|correct|EBI}} | ChEBI = 109895 | SMILES=c1ccc3c(c1)[nH]c2cnccc23 | InChI=1/C11H8N2/c1-2-4-10-8(3-1)9-5-6-12-7-11(9)13-10/h1-7,13H | MeSHName=norharman | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID=58486 }} |Section2={{Chembox Properties | Formula=C<sub>11</sub>H<sub>8</sub>N<sub>2</sub> | MolarMass=168.20 g/mol }} }}
'''β-Carboline''', also known as '''norharman''', '''norharmane''', or '''9''H''-pyrido[3,4-b]indole''', is a tricyclic chemical compound and alkaloid.<ref name="CaoPengWang2007">{{cite journal | vauthors = Cao R, Peng W, Wang Z, Xu A | title = beta-Carboline alkaloids: biochemical and pharmacological functions | journal = Curr Med Chem | volume = 14 | issue = 4 | pages = 479–500 | date = 2007 | pmid = 17305548 | doi = 10.2174/092986707779940998 | url = }}</ref> It is the parent structure of the substituted β-carbolines, a large group of alkaloids and synthetic compounds.<ref name="CaoPengWang2007" /> β-Carboline may be thought of as a cyclized tryptamine.<ref name="CaoPengWang2007" /> The compound has been found to possess a variety of pharmacological activities, including DNA mutagenic effects, imidazoline receptor interactions, serotonin reuptake inhibition, monoamine oxidase inhibition, cytochrome P450 enzyme inhibition, and inhibition of other enzymes, among others.<ref name="CaoPengWang2007" />
β-Carboline is a weak reversible inhibitor of monoamine oxidase A (RIMA), with an {{Abbrlink|IC<sub>50</sub>|half-maximal inhibitory concentration}} of 1,700{{nbsp}}nM.<ref name="SaroJohneLatino2025">{{cite journal | vauthors = Saro G, Johne S, Latino DA, Moine F, van der Toorn M, Mathis C, Veljkovic E | title = Monoamine Oxidase Inhibitors Present in Tobacco Modulate Dopamine Balance Via the Dopamine Transporter | journal = ACS Chem Neurosci | volume = 16 | issue = 6 | pages = 1117–1131 | date = March 2025 | pmid = 40033845 | pmc = 11926787 | doi = 10.1021/acschemneuro.4c00789 | url = }}</ref> It is also a weak dopamine reuptake inhibitor (DRI), with an {{Abbr|IC<sub>50</sub>|half-maximal inhibitory concentration}} of 3,040{{nbsp}}nM at the dopamine transporter (DAT).<ref name="SaroJohneLatino2025" /> The drug shows weak affinity for the serotonin 5-HT<sub>2B</sub> and 5-HT<sub>2C</sub> receptors (K<sub>i</sub> = 738{{nbsp}}nM and 2,522{{nbsp}}nM, respectively), but not for the serotonin 5-HT<sub>2A</sub> receptor (K<sub>i</sub> = >10,000{{nbsp}}nM).<ref name="FoleyAl-IssaHiller2019">{{cite journal | last1=Foley | first1=Caroline A. | last2=Al-Issa | first2=Yazan A. | last3=Hiller | first3=Kathryn P. | last4=Mulcahy | first4=Seann P. | title=Synthesis and Structure–Activity Relationships of 1-Aryl-β-carbolines as Affinity Probes for the 5-Hydroxytryptamine Receptor | journal=ACS Omega | volume=4 | issue=6 | date=30 June 2019 | issn=2470-1343 | doi=10.1021/acsomega.9b01111 | pages=9807–9812 | doi-access=free }}</ref>
==See also== * Substituted β-carboline * Tryptoline * γ-Carboline
==References== {{Reflist}}
==External links== * [https://isomerdesign.com/pihkal/explore/5414 β-Carboline - Isomer Design]
{{Serotonin receptor modulators}} {{Monoamine metabolism modulators}} {{Monoamine reuptake inhibitors}} {{Tryptamines}}
Category:Beta-Carbolines Category:Dopamine reuptake inhibitors Category:Monoamine oxidase inhibitors Category:Serotonin receptor modulators
{{Alkaloid-stub}}