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Record Information
StatusExpected but not Quantified
Creation Date2013-03-20 21:09:46 UTC
Update Date2021-01-04 21:29:02 UTC
Secondary Accession Numbers
  • HMDB59912
Metabolite Identification
Common NameIndigo Carmine
DescriptionIndigo carmine, also known as C.I. Pigment Blue 63, or indigo blue, belongs to the class of organic compounds known as indolines. Indolines are compounds containing an indole moiety, which consists of pyrrolidine ring fused to benzene to form 2,3-dihydroindole. Indigo carmine is an indigo derivative that is produced by sulfonation of indigo, which makes the compound water soluble (up to 10 g/L). Indigo carmine exists as a bright purple solid and is an extremely weak basic (essentially neutral) compound (based on its pKa). It is approved for use as a food colorant in the U.S and E.U. It is also used as a medical dye. In obstetric surgery, indigo carmine solutions are sometimes employed to detect amniotic fluid leaks. In urologic surgery, intravenous injection of indigo carmine is often used to highlight portions of the urinary tract. The dye is filtered rapidly by the kidneys from the blood, and colors the urine blue. This enables structures of the urinary tract to be seen in the surgical field and demonstrates if there is a leak. A frequently encountered cardiovascular effect of intravenous indigo carmine administration is temporary alpha-receptor stimulation. Skin discoloration may occur at high doses. According to one study, the primary action of indigo carmine appears to be at the level of nitric oxide generation and/or its release from the endothelium. In addition to this, indigo carmine appears to inhibit vascular smooth muscle guanylyl cyclase. Therefore, indigo carmine may increase blood pressure by interfering with these nitric oxide-mediated vasodilatory mechanisms. Moreover, incubation of isotopically labeled indigo carmine with intestinal contents of rats for 48 h suggested that isatin-5-sulphonic acid and 5-sulphoanthranilic acid may possibly be metabolites formed by intestinal bacterial metabolism of the drug.
2-(1,3-Dihydro-3-oxo-5-sulphO-2H-indol-2-ylidene)-3-oxoindoline-5-sulphonic acidChEBI
Indigo carmine free acidChEBI
Indigo-5,5'-disulfonic acidChEBI
Indigotindisulfonic acidChEBI
2-(1,3-Dihydro-3-oxo-5-sulfO-2H-indol-2-ylidene)-3-oxoindoline-5-sulfonic acidGenerator
Indigo-5,5'-disulphonic acidGenerator
Indigotindisulphonic acidGenerator
Indigo blueHMDB
Indigo carmineHMDB
Carmine, indigoHMDB
Indigo disulfonateHMDB
Soluble indigo blueHMDB
2-(1,3-Dihydro-3-oxo-5-sulphO-2H-indol-2-ylidene)-3- oxoindoline-5-sulphonic acidHMDB
D And C blue no. 6HMDB
Disulfonate, indigoHMDB
FD And C blue no. 2HMDB
Indigo blue, solubleHMDB
Indigotindisulfonate sodiumHMDB
Chemical FormulaC16H10N2O8S2
Average Molecular Weight422.389
Monoisotopic Molecular Weight421.987856686
IUPAC Name(E)-3,3'-dioxo-1H,1'H,3H,3'H-[2,2'-biindolylidene]-5,5'-disulfonic acid
Traditional Name(E)-3,3'-dioxo-1H,1'H-[2,2'-biindolylidene]-5,5'-disulfonic acid
CAS Registry NumberNot Available
InChI Identifier
Chemical Taxonomy
Description belongs to the class of organic compounds known as indolines. Indolines are compounds containing an indole moiety, which consists of pyrrolidine ring fused to benzene to form 2,3-dihydroindole.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassIndoles and derivatives
Sub ClassIndolines
Direct ParentIndolines
Alternative Parents
  • Arylsulfonic acid or derivatives
  • Dihydroindole
  • 1-sulfo,2-unsubstituted aromatic compound
  • Aryl ketone
  • Secondary aliphatic/aromatic amine
  • Benzenoid
  • Organic sulfonic acid or derivatives
  • Organosulfonic acid or derivatives
  • Organosulfonic acid
  • Sulfonyl
  • Vinylogous amide
  • Ketone
  • Secondary amine
  • Enamine
  • Azacycle
  • Organic nitrogen compound
  • Amine
  • Organopnictogen compound
  • Organosulfur compound
  • Organooxygen compound
  • Organonitrogen compound
  • Organic oxide
  • Hydrocarbon derivative
  • Organic oxygen compound
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External DescriptorsNot Available

Industrial application:

Physical Properties
StateNot Available
Experimental Properties
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Predicted Properties
Water Solubility0.1 g/LALOGPS
pKa (Strongest Acidic)-2.8ChemAxon
pKa (Strongest Basic)-7.7ChemAxon
Physiological Charge-2ChemAxon
Hydrogen Acceptor Count10ChemAxon
Hydrogen Donor Count4ChemAxon
Polar Surface Area166.94 ŲChemAxon
Rotatable Bond Count2ChemAxon
Refractivity101.29 m³·mol⁻¹ChemAxon
Polarizability39.65 ųChemAxon
Number of Rings4ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Spectrum TypeDescriptionSplash KeyView
Predicted GC-MSPredicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positivesplash10-0006-2749500000-b7042c12e11418d21015Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Positivesplash10-00di-0000900000-89f2c2f53b28e59acf74Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Positivesplash10-00dl-0027900000-c2c2a2e9e311e0feddd3Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Positivesplash10-03fr-0196000000-f4880a3747eaf442484eSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, Negativesplash10-00di-0000900000-fe6eb7fd27b8a2dc7f5dSpectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, Negativesplash10-00di-2021900000-791a8c28c1e7d0e8afa9Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, Negativesplash10-001i-9011000000-cc798298986c0c283422Spectrum
Biological Properties
Cellular LocationsNot Available
Biospecimen LocationsNot Available
Tissue LocationsNot Available
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDDB11577
Phenol Explorer Compound IDNot Available
FooDB IDNot Available
KNApSAcK IDNot Available
Chemspider IDNot Available
KEGG Compound IDNot Available
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkIndigo_carmine
METLIN IDNot Available
PubChem Compound5282430
PDB IDNot Available
ChEBI ID90117
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB ID
Synthesis ReferenceNot Available
Material Safety Data Sheet (MSDS)Not Available
General ReferencesNot Available