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Record Information
Version5.0
StatusDetected and Quantified
Creation Date2006-05-22 14:17:42 UTC
Update Date2021-10-13 04:38:12 UTC
HMDB IDHMDB0002209
Secondary Accession Numbers
  • HMDB02209
Metabolite Identification
Common NameEquol
DescriptionEquol is a metabolite of daidzein, a phytoestrogen common in the human diet and abundant in soy. Intestinal bacteria in humans can reduce daidzein to equol, and can be found in normal human urine. The clinical effectiveness of soy isoflavones may be a function of the ability to biotransform soy isoflavones to the more potent estrogenic metabolite, equol, which may enhance the actions of soy isoflavones, owing to its greater affinity for estrogen receptors, unique antiandrogenic properties, and superior antioxidant activity. However, not all individuals consuming daidzein produce equol. Only approximately one-third to one-half of the population is able to metabolize daidzein to equol. This high variability in equol production is presumably attributable to interindividual differences in the composition of the intestinal microflora, which may play an important role in the mechanisms of action of isoflavones. (PMID: 17579895 , 17579894 ). Equol can be found in Bacteroides, Bifidobacterium, Enterococcus, Lactobacillus and Eggerthella (PMID: 20519412 ; PMID: 18838805 ).
Structure
Data?1582752236
Synonyms
ValueSource
(+-)-Isomer OF equolMeSH
3' Hydroxy equolMeSH
3'-Hydroxy-equolMeSH
4' O Methyl equolMeSH
4' Methoxy 7 isoflavanolMeSH
4'-O-Methyl equolMeSH
4'-Methoxy-7-isoflavanolMeSH
6' Hydroxy equolMeSH
6'-Hydroxy-equolMeSH
Equol, 4'-O-methylMeSH
AUS-131(S)-equolChEMBL, HMDB
(-)-(S)-EquolHMDB
(-)-EquolHMDB
(S)-(-)-4',7-IsoflavandiolHMDB
(S)-3,4-dihydro-3-(4-Hydroxyphenyl)-2H-1-benzopyran-7-olHMDB
(S)-EquolHMDB
4',7-DihydroxyisoflavanHMDB
4',7-IsoflavandiolHMDB
Chemical FormulaC15H14O3
Average Molecular Weight242.2699
Monoisotopic Molecular Weight242.094294314
IUPAC Name(3S)-3-(4-hydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-7-ol
Traditional Name(-)-equol
CAS Registry Number531-95-3
SMILES
OC1=CC=C(C=C1)[C@H]1COC2=CC(O)=CC=C2C1
InChI Identifier
InChI=1S/C15H14O3/c16-13-4-1-10(2-5-13)12-7-11-3-6-14(17)8-15(11)18-9-12/h1-6,8,12,16-17H,7,9H2/t12-/m1/s1
InChI KeyADFCQWZHKCXPAJ-GFCCVEGCSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as isoflavanols. These are polycyclic compounds containing a hydroxylated isoflavan skeleton.
KingdomOrganic compounds
Super ClassPhenylpropanoids and polyketides
ClassIsoflavonoids
Sub ClassIsoflavans
Direct ParentIsoflavanols
Alternative Parents
Substituents
  • Hydroxyisoflavonoid
  • Isoflavanol
  • Chromane
  • Benzopyran
  • 1-benzopyran
  • Alkyl aryl ether
  • 1-hydroxy-2-unsubstituted benzenoid
  • Phenol
  • Monocyclic benzene moiety
  • Benzenoid
  • Ether
  • Oxacycle
  • Organoheterocyclic compound
  • Organooxygen compound
  • Hydrocarbon derivative
  • Organic oxygen compound
  • Aromatic heteropolycyclic compound
Molecular FrameworkAromatic heteropolycyclic compounds
External Descriptors
Ontology
Physiological effect
Disposition
Biological locationSource
ProcessNot Available
Role
Physical Properties
StateSolid
Experimental Molecular Properties
PropertyValueReference
Melting Point189.5 °CNot Available
Boiling PointNot AvailableNot Available
Water Solubility72.3 mg/L @ 25 °C (est)The Good Scents Company Information System
LogPNot AvailableNot Available
Experimental Chromatographic PropertiesNot Available
Predicted Molecular Properties
PropertyValueSource
Water Solubility0.044 g/LALOGPS
logP2.91ALOGPS
logP3.19ChemAxon
logS-3.7ALOGPS
pKa (Strongest Acidic)9.63ChemAxon
pKa (Strongest Basic)-4.9ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area49.69 ŲChemAxon
Rotatable Bond Count1ChemAxon
Refractivity68.96 m³·mol⁻¹ChemAxon
Polarizability25.81 ųChemAxon
Number of Rings3ChemAxon
BioavailabilityYesChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleNoChemAxon
MDDR-like RuleNoChemAxon
Predicted Chromatographic Properties

Predicted Collision Cross Sections

PredictorAdduct TypeCCS Value (Å2)Reference
DarkChem[M+H]+155.97931661259
DarkChem[M-H]-159.45631661259
DeepCCS[M+H]+154.59430932474
DeepCCS[M-H]-152.23630932474
DeepCCS[M-2H]-185.14230932474
DeepCCS[M+Na]+160.68730932474
AllCCS[M+H]+156.532859911
AllCCS[M+H-H2O]+152.532859911
AllCCS[M+NH4]+160.232859911
AllCCS[M+Na]+161.332859911
AllCCS[M-H]-160.132859911
AllCCS[M+Na-2H]-159.632859911
AllCCS[M+HCOO]-159.232859911

Predicted Retention Times

Underivatized

Chromatographic MethodRetention TimeReference
Measured using a Waters Acquity ultraperformance liquid chromatography (UPLC) ethylene-bridged hybrid (BEH) C18 column (100 mm × 2.1 mm; 1.7 μmparticle diameter). Predicted by Afia on May 17, 2022. Predicted by Afia on May 17, 2022.6.15 minutes32390414
Predicted by Siyang on May 30, 202212.4259 minutes33406817
Predicted by Siyang using ReTip algorithm on June 8, 20221.69 minutes32390414
AjsUoB = Accucore 150 Amide HILIC with 10mM Ammonium Formate, 0.1% Formic Acid24.2 seconds40023050
Fem_Long = Waters ACQUITY UPLC HSS T3 C18 with Water:MeOH and 0.1% Formic Acid1736.2 seconds40023050
Fem_Lipids = Ascentis Express C18 with (60:40 water:ACN):(90:10 IPA:ACN) and 10mM NH4COOH + 0.1% Formic Acid331.9 seconds40023050
Life_Old = Waters ACQUITY UPLC BEH C18 with Water:(20:80 acetone:ACN) and 0.1% Formic Acid164.6 seconds40023050
Life_New = RP Waters ACQUITY UPLC HSS T3 C18 with Water:(30:70 MeOH:ACN) and 0.1% Formic Acid192.2 seconds40023050
RIKEN = Waters ACQUITY UPLC BEH C18 with Water:ACN and 0.1% Formic Acid369.3 seconds40023050
Eawag_XBridgeC18 = XBridge C18 3.5u 2.1x50 mm with Water:MeOH and 0.1% Formic Acid609.8 seconds40023050
BfG_NTS_RP1 =Agilent Zorbax Eclipse Plus C18 (2.1 mm x 150 mm, 3.5 um) with Water:ACN and 0.1% Formic Acid459.6 seconds40023050
HILIC_BDD_2 = Merck SeQuant ZIC-HILIC with ACN(0.1% formic acid):water(16 mM ammonium formate)115.0 seconds40023050
UniToyama_Atlantis = RP Waters Atlantis T3 (2.1 x 150 mm, 5 um) with ACN:Water and 0.1% Formic Acid1154.3 seconds40023050
BDD_C18 = Hypersil Gold 1.9µm C18 with Water:ACN and 0.1% Formic Acid441.1 seconds40023050
UFZ_Phenomenex = Kinetex Core-Shell C18 2.6 um, 3.0 x 100 mm, Phenomenex with Water:MeOH and 0.1% Formic Acid1279.9 seconds40023050
SNU_RIKEN_POS = Waters ACQUITY UPLC BEH C18 with Water:ACN and 0.1% Formic Acid378.2 seconds40023050
RPMMFDA = Waters ACQUITY UPLC BEH C18 with Water:ACN and 0.1% Formic Acid351.9 seconds40023050
MTBLS87 = Merck SeQuant ZIC-pHILIC column with ACN:Water and :ammonium carbonate381.0 seconds40023050
KI_GIAR_zic_HILIC_pH2_7 = Merck SeQuant ZIC-HILIC with ACN:Water and 0.1% FA219.3 seconds40023050
Meister zic-pHILIC pH9.3 = Merck SeQuant ZIC-pHILIC column with ACN:Water 5mM NH4Ac pH9.3 and 5mM ammonium acetate in water66.4 seconds40023050

Predicted Kovats Retention Indices

Underivatized

MetaboliteSMILESKovats RI ValueColumn TypeReference
EquolOC1=CC=C(C=C1)[C@H]1COC2=CC(O)=CC=C2C13233.6Standard polar33892256
EquolOC1=CC=C(C=C1)[C@H]1COC2=CC(O)=CC=C2C12523.9Standard non polar33892256
EquolOC1=CC=C(C=C1)[C@H]1COC2=CC(O)=CC=C2C12602.9Semi standard non polar33892256

Derivatized

Derivative Name / StructureSMILESKovats RI ValueColumn TypeReference
Equol,1TMS,isomer #1C[Si](C)(C)OC1=CC=C([C@H]2COC3=CC(O)=CC=C3C2)C=C12511.2Semi standard non polar33892256
Equol,1TMS,isomer #2C[Si](C)(C)OC1=CC=C2C[C@@H](C3=CC=C(O)C=C3)COC2=C12505.5Semi standard non polar33892256
Equol,2TMS,isomer #1C[Si](C)(C)OC1=CC=C([C@H]2COC3=CC(O[Si](C)(C)C)=CC=C3C2)C=C12484.9Semi standard non polar33892256
Equol,1TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=CC=C([C@H]2COC3=CC(O)=CC=C3C2)C=C12782.8Semi standard non polar33892256
Equol,1TBDMS,isomer #2CC(C)(C)[Si](C)(C)OC1=CC=C2C[C@@H](C3=CC=C(O)C=C3)COC2=C12778.8Semi standard non polar33892256
Equol,2TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=CC=C([C@H]2COC3=CC(O[Si](C)(C)C(C)(C)C)=CC=C3C2)C=C13029.7Semi standard non polar33892256
Spectra

GC-MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Predicted GC-MSPredicted GC-MS Spectrum - Equol GC-MS (Non-derivatized) - 70eV, Positivesplash10-03dl-2590000000-de6943a0e29cb74d29c42017-09-01Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Equol GC-MS (2 TMS) - 70eV, Positivesplash10-00di-6439000000-bd3446db9a81b442105b2017-10-06Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - Equol GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum

MS/MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 10V, Positive-QTOFsplash10-006x-0890000000-7e7596ef550328bb2d8b2016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 20V, Positive-QTOFsplash10-00di-0950000000-eb2fba880af94e2ffaa42016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 40V, Positive-QTOFsplash10-0adi-5910000000-ae99af1d6277808c807a2016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 10V, Negative-QTOFsplash10-0006-0390000000-9e81ff09baf0494659552016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 20V, Negative-QTOFsplash10-0006-0390000000-23c63d12aef21bc1a2fe2016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 40V, Negative-QTOFsplash10-0603-4930000000-18ce0b21dd8e144014a52016-08-03Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 10V, Positive-QTOFsplash10-0005-0960000000-9edad7cf7d51f7a71fee2021-09-21Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 20V, Positive-QTOFsplash10-0006-0590000000-19e7c74a42b427564aac2021-09-21Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 40V, Positive-QTOFsplash10-056r-4930000000-a7500058dae2b15f912b2021-09-21Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 10V, Negative-QTOFsplash10-006x-0970000000-7b598fa2edd4a41a1f9b2021-09-25Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 20V, Negative-QTOFsplash10-00kf-1970000000-4a2a37c7a8d430f4f1642021-09-25Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - Equol 40V, Negative-QTOFsplash10-014i-3910000000-5790b5708e0e13e02c982021-09-25Wishart LabView Spectrum
Biological Properties
Cellular Locations
  • Membrane (predicted from logP)
Biospecimen Locations
  • Blood
  • Urine
Tissue LocationsNot Available
Pathways
Normal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
BloodDetected and Quantified0.0006 (0.00057 - 0.0007) uMAdult (>18 years old)FemaleNormal details
BloodDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothNormal details
BloodDetected and Quantified0.0006 uMAdult (>18 years old)FemaleNormal details
BloodDetected and Quantified0.00056 uMAdult (>18 years old)FemaleNormal details
BloodDetected and Quantified0.000413 uMAdult (>18 years old)FemaleNormal details
BloodDetected and Quantified0.0002 uMAdult (>18 years old)FemaleNormal details
BloodDetected and Quantified0.0006 (0.00057 - 0.00066) uMAdult (>18 years old)MaleNormal details
UrineDetected and Quantified0.0574 +/- 0.198 umol/mmol creatinineAdult (>18 years old)Female
Normal
details
UrineDetected and Quantified0.0393 +/- 0.128 umol/mmol creatinineAdult (>18 years old)Female
Normal
details
UrineDetected and Quantified0.000867 umol/mmol creatinineAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.00686 umol/mmol creatinineChildren (1 - 13 years old)BothNormal details
UrineDetected and Quantified0.0167 +/- 0.0680 umol/mmol creatinineAdult (>18 years old)BothNormal details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineDetected and Quantified0.000413 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineDetected and Quantified0.13 +/- 0.12 (0.0061-0.623) umol/mmol creatinineAdult (>18 years old)BothNormal details
UrineDetected and Quantified0.00433 umol/mmol creatinineChildren (1 - 13 years old)FemaleNormal details
UrineDetected and Quantified0.00452 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineDetected and Quantified0.0124 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineDetected and Quantified0.0904 umol/mmol creatinineChildren (1-13 years old)FemaleNormal details
UrineDetected and Quantified0.283 umol/mmol creatinineChildren (1-13 years old)FemaleNormal details
UrineDetected and Quantified0.00288 +/- 0.0147 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineDetected and Quantified0.00320 +/- 0.0160 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineDetected and Quantified0.0112 +/- 0.0368 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineDetected and Quantified0.0144 +/- 0.0272 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineDetected and Quantified0.0320 +/- 0.0880 umol/mmol creatinineAdult (>18 years old)FemaleNormal details
UrineDetected but not QuantifiedNot QuantifiedAdult (>18 years old)BothNormal details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineExpected but not QuantifiedNot QuantifiedNot AvailableNot AvailableConsuming polyphenols described by Phenol-Explorer entry 866 details
UrineDetected and Quantified0.06 (0.01-0.10) umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified0.00327 (0.00275-0.00388) umol/mmol creatinineAdult (>18 years old)Not SpecifiedNormal
    • National Health a...
details
UrineDetected and Quantified0.00625 (0.00504-0.00775) umol/mmol creatinineChildren (1-13 years old)Not SpecifiedNormal
    • National Health a...
details
UrineDetected and Quantified0.00333 umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified0.00590 +/- 0.0120 umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected but not QuantifiedNot QuantifiedAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified1.560 +/- 1.780 umol/mmol creatinineAdult (>18 years old)Female
Normal
details
UrineDetected and Quantified0.00533 +/- 0.00600 umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified0.00533 +/- 0.00533 umol/mmol creatinineAdult (>18 years old)Both
Normal
details
UrineDetected and Quantified0.440 +/- 0.807 umol/mmol creatinineAdult (>18 years old)Female
Normal
details
Abnormal Concentrations
BiospecimenStatusValueAgeSexConditionReferenceDetails
UrineDetected and Quantified0 - 36.7 umol/mmol creatinineAdult (>18 years old)BothSoy consumption (ileostomies) details
Associated Disorders and Diseases
Disease References
Ileostomy
  1. Walsh KR, Haak SJ, Bohn T, Tian Q, Schwartz SJ, Failla ML: Isoflavonoid glucosides are deconjugated and absorbed in the small intestine of human subjects with ileostomies. Am J Clin Nutr. 2007 Apr;85(4):1050-6. [PubMed:17413104 ]
Associated OMIM IDsNone
DrugBank IDDB11674
Phenol Explorer Compound IDNot Available
FooDB IDFDB021824
KNApSAcK IDC00009707
Chemspider ID82594
KEGG Compound IDC14131
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia LinkEquol
METLIN IDNot Available
PubChem Compound91469
PDB IDNot Available
ChEBI ID428126
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB IDMDB00000385
Good Scents IDrw1732471
References
Synthesis ReferenceWang, Xiu-Ling; Hur, Hor-Gil; Lee, Je Hyeon; Kim, Ki Tae; Kim, Su-Il. Enantioselective synthesis of S-equol from dihydrodaidzein by a newly isolated anaerobic human intestinal bacterium. Applied and Environmental Microbiology (2005), 71(1), 214-219
Material Safety Data Sheet (MSDS)Download (PDF)
General References
  1. Yuan JP, Wang JH, Liu X: Metabolism of dietary soy isoflavones to equol by human intestinal microflora--implications for health. Mol Nutr Food Res. 2007 Jul;51(7):765-81. [PubMed:17579894 ]
  2. Moors S, Blaszkewicz M, Bolt HM, Degen GH: Simultaneous determination of daidzein, equol, genistein and bisphenol A in human urine by a fast and simple method using SPE and GC-MS. Mol Nutr Food Res. 2007 Jul;51(7):787-98. [PubMed:17579895 ]
  3. Setchell KD, Clerici C: Equol: history, chemistry, and formation. J Nutr. 2010 Jul;140(7):1355S-62S. doi: 10.3945/jn.109.119776. Epub 2010 Jun 2. [PubMed:20519412 ]
  4. Yokoyama S, Suzuki T: Isolation and characterization of a novel equol-producing bacterium from human feces. Biosci Biotechnol Biochem. 2008 Oct;72(10):2660-6. doi: 10.1271/bbb.80329. Epub 2008 Oct 7. [PubMed:18838805 ]