ContaminantDB: Equol

Identification Taxonomy Biological Properties Physical Properties Toxicity Profile Spectra Concentrations Links References Targets (2)XML

Record Information

Version

1.0

Creation Date

2014-08-29 04:47:27 UTC

Update Date

2026-04-14 18:19:40 UTC

Accession Number

CHEM002922

Identification

Common Name

Equol

Class

Small Molecule

Description

Equol 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. (1, 2).

Contaminant Sources

FooDB Chemicals
HMDB Contaminants - Urine
T3DB toxins

Contaminant Type

Animal Toxin
Ether
Food Toxin
Industrial/Workplace Toxin
Metabolite
Natural Compound
Organic Compound

Chemical Structure

MOL SDF 3D-SDF PDB SMILES InChI View 3D Structure

Synonyms

Value	Source
(+-)-Isomer OF equol	MeSH
3' Hydroxy equol	MeSH
3'-Hydroxy-equol	MeSH
4' O Methyl equol	MeSH
4' Methoxy 7 isoflavanol	MeSH
4'-O-Methyl equol	MeSH
4'-Methoxy-7-isoflavanol	MeSH
6' Hydroxy equol	MeSH
6'-Hydroxy-equol	MeSH
Equol, 4'-O-methyl	MeSH
AUS-131(S)-equol	ChEMBL, HMDB
(-)-(S)-Equol	HMDB
(-)-Equol	HMDB
(S)-(-)-4',7-Isoflavandiol	HMDB
(S)-3,4-dihydro-3-(4-Hydroxyphenyl)-2H-1-benzopyran-7-ol	HMDB
(S)-Equol	HMDB
4',7-Dihydroxyisoflavan	HMDB
4',7-Isoflavandiol	HMDB

Chemical Formula

C₁₅H₁₄O₃

Average Molecular Mass

242.270 g/mol

Monoisotopic Mass

242.094 g/mol

CAS Registry Number

531-95-3

IUPAC Name

(3S)-3-(4-hydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-7-ol

Traditional Name

(-)-equol

SMILES

OC1=CC=C(C=C1)[C@H]1COC2=C(C1)C=CC(O)=C2

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 Key

ADFCQWZHKCXPAJ-GFCCVEGCSA-N

Chemical Taxonomy

Description

belongs to the class of organic compounds known as isoflavanols. These are polycyclic compounds containing a hydroxylated isoflavan skeleton.

Kingdom

Organic compounds

Super Class

Phenylpropanoids and polyketides

Class

Isoflavonoids

Sub Class

Isoflavans

Direct Parent

Isoflavanols

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 Framework

Aromatic heteropolycyclic compounds

External Descriptors

hydroxyisoflavans (CHEBI:34741 )
isoflavans (C14131 )
Isoflavanes (C14131 )

Biological Properties

Status

Detected and Not Quantified

Origin

Exogenous

Cellular Locations

Membrane

Biofluid Locations

Not Available

Tissue Locations

Not Available

Pathways

Not Available

Applications

Not Available

Biological Roles

Not Available

Chemical Roles

Not Available

Physical Properties

State

Solid

Appearance

White powder.

Experimental Properties

Property	Value
Melting Point	189.5°C
Boiling Point	Not Available
Solubility	Not Available

Predicted Properties

Property	Value	Source
Water Solubility	0.044 g/L	ALOGPS
logP	2.91	ALOGPS
logP	3.19	ChemAxon
logS	-3.7	ALOGPS
pKa (Strongest Acidic)	9.63	ChemAxon
pKa (Strongest Basic)	-4.9	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	3	ChemAxon
Hydrogen Donor Count	2	ChemAxon
Polar Surface Area	49.69 Å²	ChemAxon
Rotatable Bond Count	1	ChemAxon
Refractivity	68.96 m³·mol⁻¹	ChemAxon
Polarizability	25.81 Å³	ChemAxon
Number of Rings	3	ChemAxon
Bioavailability	1	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	No	ChemAxon
MDDR-like Rule	No	ChemAxon

Spectra

Spectrum Type	Description	Splash Key	View
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-03dl-2590000000-de6943a0e29cb74d29c4	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (2 TMS) - 70eV, Positive	splash10-00di-6439000000-bd3446db9a81b442105b	Spectrum
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-006x-0890000000-7e7596ef550328bb2d8b	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-00di-0950000000-eb2fba880af94e2ffaa4	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-0adi-5910000000-ae99af1d6277808c807a	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-0006-0390000000-9e81ff09baf049465955	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-0006-0390000000-23c63d12aef21bc1a2fe	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-0603-4930000000-18ce0b21dd8e144014a5	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-0005-0960000000-9edad7cf7d51f7a71fee	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-0006-0590000000-19e7c74a42b427564aac	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-056r-4930000000-a7500058dae2b15f912b	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-006x-0970000000-7b598fa2edd4a41a1f9b	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-00kf-1970000000-4a2a37c7a8d430f4f164	Spectrum
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-014i-3910000000-5790b5708e0e13e02c98	Spectrum

Toxicity Profile

Route of Exposure

Not Available

Mechanism of Toxicity

Not Available

Metabolism

Not Available

Toxicity Values

Not Available

Lethal Dose

Not Available

Carcinogenicity (IARC Classification)

No indication of carcinogenicity to humans (not listed by IARC).

Uses/Sources

Intestinal bacteria in humans can reduce daidzein to equol, and can be found in normal human urine.

Minimum Risk Level

Not Available

Health Effects

Not Available

Symptoms

Not Available

Treatment

Not Available

Concentrations

Not Available

External Links

DrugBank ID

DB11674

HMDB ID

HMDB0002209

FooDB ID

FDB021824

Phenol Explorer ID

Not Available

KNApSAcK ID

C00009707

BiGG ID

Not Available

BioCyc ID

Not Available

METLIN ID

Not Available

PDB ID

Not Available

Wikipedia Link

Chemspider ID

ChEBI ID

PubChem Compound ID

Kegg Compound ID

YMDB ID

Not Available

ECMDB ID

Not Available

References

Synthesis Reference

Wang, 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

MSDS

Link

General References

1. King RA, Mano MM, Head RJ: Assessment of isoflavonoid concentrations in Australian bovine milk samples. J Dairy Res. 1998 Aug;65(3):479-89.

2. Antignac JP, Cariou R, Le Bizec B, Cravedi JP, Andre F: Identification of phytoestrogens in bovine milk using liquid chromatography/electrospray tandem mass spectrometry. Rapid Commun Mass Spectrom. 2003;17(12):1256-64. doi: 10.1002/rcm.1052.

3. Hoikkala A, Mustonen E, Saastamoinen I, Jokela T, Taponen J, Saloniemi H, Wahala K: High levels of equol in organic skimmed Finnish cow milk. Mol Nutr Food Res. 2007 Jul;51(7):782-6. doi: 10.1002/mnfr.200600222.

4. Steinshamn H, Purup S, Thuen E, Hansen-Moller J: Effects of clover-grass silages and concentrate supplementation on the content of phytoestrogens in dairy cow milk. J Dairy Sci. 2008 Jul;91(7):2715-25. doi: 10.3168/jds.2007-0857.

5. Nielsen TS, Norgaard JV, Purup S, Frette XC, Bonefeld-Jorgensen EC: Estrogenic activity of bovine milk high or low in equol using immature mouse uterotrophic responses and an estrogen receptor transactivation assay. Cancer Epidemiol. 2009 Jul;33(1):61-8. doi: 10.1016/j.canep.2009.04.003. Epub 2009 May 31.

6. Shin Tsen, Jinyi Siew, Eunice Lau, Farzana A qah Bte Roslee, Hui Chan, Wai Loke Cow’s milk as a dietary source of equol and phenolic antioxidants: di erential distribution in the milk aqueous and lipid fractions. Dairy Sci. & Technol. (2014) 94:625–632. DOI 10.1007/s13594-014-0183-4

7. Wang, 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

8. 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.

9. 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.

10. 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.

11. 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.

Equol (CHEM002922)

Structure for CHEM002922: Equol