Record Information
Version1.0
StatusDetected and Quantified
Creation Date2020-10-27 23:37:37 UTC
Update Date2022-12-15 22:51:38 UTC
Metabolite IDMMDBc0000004
Metabolite Identification
Common NameIndole
DescriptionIndole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. The participation of the nitrogen lone electron pair in the aromatic ring means that indole is not a base, and it does not behave like a simple amine. Indole is a microbial metabolite and it can be produced by bacteria as a degradation product of the amino acid tryptophan. It occurs naturally in human feces and has an intense fecal smell. At very low concentrations, however, indole has a flowery smell and is a constituent of many flower scents (such as orange blossoms) and perfumes. As a volatile organic compound, indole has been identified as a fecal biomarker of Clostridium difficile infection (PMID: 30986230 ). Natural jasmine oil, used in the perfume industry, contains around 2.5% of indole. Indole also occurs in coal tar. Indole has been found to be produced in a number of bacterial genera including Alcaligenes, Aspergillus, Escherichia, and Pseudomonas (PMID: 23194589 , 2310183 , 9680309 ). Indole plays a role in bacterial biofilm formation, bacterial motility, bacterial virulence, plasmid stability, and antibiotic resistance. It also functions as an intercellular signalling molecule (PMID: 26115989 ). Recently, it was determined that the bacterial membrane-bound histidine sensor kinase (HK) known as CpxA acts as a bacterial indole sensor to facilitate signalling (PMID: 31164470 ). It has been found that decreased indole concentrations in the gut promote bacterial pathogenesis, while increased levels of indole in the gut decrease bacterial virulence gene expression (PMID: 31164470 ). As a result, enteric pathogens sense a gradient of indole concentrations in the gut to migrate to different niches and successfully establish an infection.
Structure
Synonyms
ValueSource
2,3-BenzopyrroleChEBI
indolChEBI
1-AzaindeneHMDB
1-BenzazoleHMDB
Benzo[b]pyrroleHMDB
KetoleHMDB
IndoleHMDB
Molecular FormulaC8H7N
Average Mass117.1479
Monoisotopic Mass117.057849229
IUPAC Name1H-indole
Traditional Nameindole
CAS Registry Number120-72-9
SMILES
N1C=CC2=C1C=CC=C2
InChI Identifier
InChI=1S/C8H7N/c1-2-4-8-7(3-1)5-6-9-8/h1-6,9H
InChI KeySIKJAQJRHWYJAI-UHFFFAOYSA-N