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Record Information
Version5.0
StatusExpected but not Quantified
Creation Date2005-11-16 15:48:42 UTC
Update Date2022-03-07 02:49:01 UTC
HMDB IDHMDB0000406
Secondary Accession Numbers
  • HMDB00406
Metabolite Identification
Common Name16-Ketoestradiol
Description16-Ketoestradiol is found in the estrogen patch. The estrogen patch is a delivery system for estradiol used as hormone replacement therapy to treat the symptoms of menopause, such as hot flashes and vaginal dryness, and to prevent osteoporosis. Originally marketed as Vivelle (Novartis), it was discontinued in 2003 and reintroduced in a smaller form as Vivelle-Dot. Although the estrogen is given transdermally rather than in the standard oral tablets, the estrogen patch carries similar risks and benefits as more conventional forms of estrogen-only hormone replacement therapy.
Structure
Data?1582752129
Synonyms
ValueSource
16-oxo-17beta-EstradiolKegg
16-oxo-17b-EstradiolGenerator
16-oxo-17Β-estradiolGenerator
1,3,5(10)-Estratriene-3,17b-diol-16-oneHMDB
16-Keto-17b-estradiolHMDB
16-OxoestradiolHMDB
16-Oxoestradiol-17bHMDB
3,17b-Dihydroxyestra-1,3,5(10)-trien-16-oneHMDB
16-Ketoestradiol, (17beta)-isomer, 4-(14)C-labeledHMDB
16-Ketoestradiol, (17alpha)-isomerHMDB
(17beta)-3,17-Dihydroxyestra-1,3,5(10)-trien-16-oneHMDB
Chemical FormulaC18H22O3
Average Molecular Weight286.3655
Monoisotopic Molecular Weight286.15689457
IUPAC Name(1S,10R,11S,14R,15S)-5,14-dihydroxy-15-methyltetracyclo[8.7.0.0²,⁷.0¹¹,¹⁵]heptadeca-2(7),3,5-trien-13-one
Traditional Name16-ketoestradiol
CAS Registry Number566-75-6
SMILES
[H][C@@]12CC(=O)[C@H](O)[C@@]1(C)CC[C@]1([H])C3=C(CC[C@@]21[H])C=C(O)C=C3
InChI Identifier
InChI=1S/C18H22O3/c1-18-7-6-13-12-5-3-11(19)8-10(12)2-4-14(13)15(18)9-16(20)17(18)21/h3,5,8,13-15,17,19,21H,2,4,6-7,9H2,1H3/t13-,14-,15+,17+,18+/m1/s1
InChI KeyKJDGFQJCHFJTRH-YONAWACDSA-N
Chemical Taxonomy
Description Belongs to the class of organic compounds known as estrogens and derivatives. These are steroids with a structure containing a 3-hydroxylated estrane.
KingdomOrganic compounds
Super ClassLipids and lipid-like molecules
ClassSteroids and steroid derivatives
Sub ClassEstrane steroids
Direct ParentEstrogens and derivatives
Alternative Parents
Substituents
  • Estrogen-skeleton
  • 3-hydroxysteroid
  • Hydroxysteroid
  • 16-oxosteroid
  • Oxosteroid
  • 17-hydroxysteroid
  • Phenanthrene
  • Tetralin
  • 1-hydroxy-2-unsubstituted benzenoid
  • Benzenoid
  • Cyclic alcohol
  • Secondary alcohol
  • Ketone
  • Cyclic ketone
  • Carbonyl group
  • Organooxygen compound
  • Alcohol
  • Hydrocarbon derivative
  • Organic oxide
  • Organic oxygen compound
  • Aromatic homopolycyclic compound
Molecular FrameworkAromatic homopolycyclic compounds
External Descriptors
Ontology
Physiological effectNot Available
Disposition
Process
Role
Physical Properties
StateSolid
Experimental Molecular Properties
PropertyValueReference
Melting PointNot AvailableNot Available
Boiling PointNot AvailableNot Available
Water SolubilityNot AvailableNot Available
LogPNot AvailableNot Available
Experimental Chromatographic PropertiesNot Available
Predicted Molecular Properties
PropertyValueSource
Water Solubility0.046 g/LALOGPS
logP2.4ALOGPS
logP3.08ChemAxon
logS-3.8ALOGPS
pKa (Strongest Acidic)10.33ChemAxon
pKa (Strongest Basic)-3.7ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count3ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area57.53 ŲChemAxon
Rotatable Bond Count0ChemAxon
Refractivity80.37 m³·mol⁻¹ChemAxon
Polarizability32.35 ųChemAxon
Number of Rings4ChemAxon
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]+166.93531661259
DarkChem[M-H]-165.44631661259
AllCCS[M+H]+170.4832859911
AllCCS[M-H]-175.41632859911
DeepCCS[M-2H]-211.50530932474
DeepCCS[M+Na]+186.33530932474
AllCCS[M+H]+170.532859911
AllCCS[M+H-H2O]+167.232859911
AllCCS[M+NH4]+173.632859911
AllCCS[M+Na]+174.432859911
AllCCS[M-H]-175.432859911
AllCCS[M+Na-2H]-175.232859911
AllCCS[M+HCOO]-175.032859911

Predicted Kovats Retention Indices

Underivatized

MetaboliteSMILESKovats RI ValueColumn TypeReference
16-Ketoestradiol[H][C@@]12CC(=O)[C@H](O)[C@@]1(C)CC[C@]1([H])C3=C(CC[C@@]21[H])C=C(O)C=C33624.1Standard polar33892256
16-Ketoestradiol[H][C@@]12CC(=O)[C@H](O)[C@@]1(C)CC[C@]1([H])C3=C(CC[C@@]21[H])C=C(O)C=C32807.0Standard non polar33892256
16-Ketoestradiol[H][C@@]12CC(=O)[C@H](O)[C@@]1(C)CC[C@]1([H])C3=C(CC[C@@]21[H])C=C(O)C=C32864.2Semi standard non polar33892256

Derivatized

Derivative Name / StructureSMILESKovats RI ValueColumn TypeReference
16-Ketoestradiol,1TMS,isomer #1C[C@]12CC[C@@H]3C4=CC=C(O)C=C4CC[C@H]3[C@@H]1CC(=O)[C@@H]2O[Si](C)(C)C2832.6Semi standard non polar33892256
16-Ketoestradiol,1TMS,isomer #2C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1CC(=O)[C@@H]2O2823.5Semi standard non polar33892256
16-Ketoestradiol,1TMS,isomer #3C[C@]12CC[C@@H]3C4=CC=C(O)C=C4CC[C@H]3[C@@H]1CC(O[Si](C)(C)C)=C2O2764.1Semi standard non polar33892256
16-Ketoestradiol,1TMS,isomer #4C[C@]12CC[C@@H]3C4=CC=C(O)C=C4CC[C@H]3[C@@H]1C=C(O[Si](C)(C)C)[C@@H]2O2734.5Semi standard non polar33892256
16-Ketoestradiol,2TMS,isomer #1C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1CC(=O)[C@@H]2O[Si](C)(C)C2904.1Semi standard non polar33892256
16-Ketoestradiol,2TMS,isomer #2C[C@]12CC[C@@H]3C4=CC=C(O)C=C4CC[C@H]3[C@@H]1CC(O[Si](C)(C)C)=C2O[Si](C)(C)C2779.4Semi standard non polar33892256
16-Ketoestradiol,2TMS,isomer #3C[C@]12CC[C@@H]3C4=CC=C(O)C=C4CC[C@H]3[C@@H]1C=C(O[Si](C)(C)C)[C@@H]2O[Si](C)(C)C2749.9Semi standard non polar33892256
16-Ketoestradiol,2TMS,isomer #4C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1CC(O[Si](C)(C)C)=C2O2845.2Semi standard non polar33892256
16-Ketoestradiol,2TMS,isomer #5C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1C=C(O[Si](C)(C)C)[C@@H]2O2762.3Semi standard non polar33892256
16-Ketoestradiol,3TMS,isomer #1C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1CC(O[Si](C)(C)C)=C2O[Si](C)(C)C2905.4Semi standard non polar33892256
16-Ketoestradiol,3TMS,isomer #1C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1CC(O[Si](C)(C)C)=C2O[Si](C)(C)C2783.1Standard non polar33892256
16-Ketoestradiol,3TMS,isomer #1C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1CC(O[Si](C)(C)C)=C2O[Si](C)(C)C2899.0Standard polar33892256
16-Ketoestradiol,3TMS,isomer #2C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1C=C(O[Si](C)(C)C)[C@@H]2O[Si](C)(C)C2836.6Semi standard non polar33892256
16-Ketoestradiol,3TMS,isomer #2C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1C=C(O[Si](C)(C)C)[C@@H]2O[Si](C)(C)C2748.6Standard non polar33892256
16-Ketoestradiol,3TMS,isomer #2C[C@]12CC[C@@H]3C4=CC=C(O[Si](C)(C)C)C=C4CC[C@H]3[C@@H]1C=C(O[Si](C)(C)C)[C@@H]2O[Si](C)(C)C2890.0Standard polar33892256
16-Ketoestradiol,1TBDMS,isomer #1CC(C)(C)[Si](C)(C)O[C@H]1C(=O)C[C@H]2[C@@H]3CCC4=CC(O)=CC=C4[C@H]3CC[C@@]21C3108.2Semi standard non polar33892256
16-Ketoestradiol,1TBDMS,isomer #2CC(C)(C)[Si](C)(C)OC1=CC=C2C(=C1)CC[C@@H]1[C@@H]2CC[C@@]2(C)[C@H]1CC(=O)[C@@H]2O3110.8Semi standard non polar33892256
16-Ketoestradiol,1TBDMS,isomer #3CC(C)(C)[Si](C)(C)OC1=C(O)[C@@]2(C)CC[C@@H]3C4=CC=C(O)C=C4CC[C@H]3[C@@H]2C13044.1Semi standard non polar33892256
16-Ketoestradiol,1TBDMS,isomer #4CC(C)(C)[Si](C)(C)OC1=C[C@H]2[C@@H]3CCC4=CC(O)=CC=C4[C@H]3CC[C@]2(C)[C@H]1O2996.5Semi standard non polar33892256
16-Ketoestradiol,2TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=CC=C2C(=C1)CC[C@@H]1[C@@H]2CC[C@@]2(C)[C@H]1CC(=O)[C@@H]2O[Si](C)(C)C(C)(C)C3432.7Semi standard non polar33892256
16-Ketoestradiol,2TBDMS,isomer #2CC(C)(C)[Si](C)(C)OC1=C(O[Si](C)(C)C(C)(C)C)[C@@]2(C)CC[C@@H]3C4=CC=C(O)C=C4CC[C@H]3[C@@H]2C13287.1Semi standard non polar33892256
16-Ketoestradiol,2TBDMS,isomer #3CC(C)(C)[Si](C)(C)OC1=C[C@H]2[C@@H]3CCC4=CC(O)=CC=C4[C@H]3CC[C@]2(C)[C@H]1O[Si](C)(C)C(C)(C)C3234.6Semi standard non polar33892256
16-Ketoestradiol,2TBDMS,isomer #4CC(C)(C)[Si](C)(C)OC1=C(O)[C@@]2(C)CC[C@@H]3C4=CC=C(O[Si](C)(C)C(C)(C)C)C=C4CC[C@H]3[C@@H]2C13320.0Semi standard non polar33892256
16-Ketoestradiol,2TBDMS,isomer #5CC(C)(C)[Si](C)(C)OC1=C[C@H]2[C@@H]3CCC4=CC(O[Si](C)(C)C(C)(C)C)=CC=C4[C@H]3CC[C@]2(C)[C@H]1O3261.6Semi standard non polar33892256
16-Ketoestradiol,3TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=C(O[Si](C)(C)C(C)(C)C)[C@@]2(C)CC[C@@H]3C4=CC=C(O[Si](C)(C)C(C)(C)C)C=C4CC[C@H]3[C@@H]2C13616.3Semi standard non polar33892256
16-Ketoestradiol,3TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=C(O[Si](C)(C)C(C)(C)C)[C@@]2(C)CC[C@@H]3C4=CC=C(O[Si](C)(C)C(C)(C)C)C=C4CC[C@H]3[C@@H]2C13466.0Standard non polar33892256
16-Ketoestradiol,3TBDMS,isomer #1CC(C)(C)[Si](C)(C)OC1=C(O[Si](C)(C)C(C)(C)C)[C@@]2(C)CC[C@@H]3C4=CC=C(O[Si](C)(C)C(C)(C)C)C=C4CC[C@H]3[C@@H]2C13214.0Standard polar33892256
16-Ketoestradiol,3TBDMS,isomer #2CC(C)(C)[Si](C)(C)OC1=C[C@H]2[C@@H]3CCC4=CC(O[Si](C)(C)C(C)(C)C)=CC=C4[C@H]3CC[C@]2(C)[C@H]1O[Si](C)(C)C(C)(C)C3549.5Semi standard non polar33892256
16-Ketoestradiol,3TBDMS,isomer #2CC(C)(C)[Si](C)(C)OC1=C[C@H]2[C@@H]3CCC4=CC(O[Si](C)(C)C(C)(C)C)=CC=C4[C@H]3CC[C@]2(C)[C@H]1O[Si](C)(C)C(C)(C)C3366.3Standard non polar33892256
16-Ketoestradiol,3TBDMS,isomer #2CC(C)(C)[Si](C)(C)OC1=C[C@H]2[C@@H]3CCC4=CC(O[Si](C)(C)C(C)(C)C)=CC=C4[C@H]3CC[C@]2(C)[C@H]1O[Si](C)(C)C(C)(C)C3197.7Standard polar33892256
Spectra

GC-MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (Non-derivatized) - 70eV, Positivesplash10-0ab9-2890000000-32071d38f05cd2ca0c9b2017-09-01Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (2 TMS) - 70eV, Positivesplash10-01dj-1196500000-273f84f940ea3f0838d02017-10-06Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (Non-derivatized) - 70eV, PositiveNot Available2021-10-12Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_1_1) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_1_2) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_1_3) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_1_4) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_2_2) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_2_3) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_2_4) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TMS_2_5) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_1_1) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_1_2) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_1_3) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_1_4) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_2_1) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_2_2) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_2_3) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_2_4) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum
Predicted GC-MSPredicted GC-MS Spectrum - 16-Ketoestradiol GC-MS (TBDMS_2_5) - 70eV, PositiveNot Available2021-11-05Wishart LabView Spectrum

MS/MS Spectra

Spectrum TypeDescriptionSplash KeyDeposition DateSourceView
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 10V, Positive-QTOFsplash10-000i-0090000000-55a266ba34ecf6bdfd112017-09-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 20V, Positive-QTOFsplash10-0a4i-0390000000-ffb77059d15a727397bb2017-09-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 40V, Positive-QTOFsplash10-0gb9-5690000000-c133890ef184dc5ec5852017-09-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 10V, Negative-QTOFsplash10-000i-0090000000-f86f24db58f0d8c366212017-09-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 20V, Negative-QTOFsplash10-000i-0090000000-a4dfb2cdc949c3369ad42017-09-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 40V, Negative-QTOFsplash10-02bf-2090000000-ce1f2fe2172e07fbffc62017-09-01Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 10V, Positive-QTOFsplash10-000i-0090000000-ed97c93b7e7537d3f95c2021-09-24Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 20V, Positive-QTOFsplash10-00n0-0590000000-4aa6f11d398258fe6ed62021-09-24Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 40V, Positive-QTOFsplash10-00fs-0930000000-15b323540fb6bb7af8e72021-09-24Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 10V, Negative-QTOFsplash10-000i-0090000000-fcaf0435bbf678a207f72021-09-24Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 20V, Negative-QTOFsplash10-000i-0090000000-555b35bd0b896dc0c5742021-09-24Wishart LabView Spectrum
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 16-Ketoestradiol 40V, Negative-QTOFsplash10-004i-0090000000-d8910a82c7c88f5cf2bb2021-09-24Wishart LabView Spectrum
Biological Properties
Cellular Locations
  • Extracellular
  • Membrane (predicted from logP)
Biospecimen LocationsNot Available
Tissue LocationsNot Available
Pathways
Normal Concentrations
Not Available
Abnormal Concentrations
Not Available
Associated Disorders and Diseases
Disease ReferencesNone
Associated OMIM IDsNone
DrugBank IDNot Available
Phenol Explorer Compound IDNot Available
FooDB IDFDB022022
KNApSAcK IDNot Available
Chemspider ID59791
KEGG Compound IDC14383
BioCyc IDNot Available
BiGG IDNot Available
Wikipedia Link16-Ketoestradiol
METLIN ID5395
PubChem Compound66417
PDB IDNot Available
ChEBI ID1150238
Food Biomarker OntologyNot Available
VMH IDNot Available
MarkerDB IDNot Available
Good Scents IDNot Available
References
Synthesis ReferenceTong, Zhengshou; Gan, Guizhi; Li, Lu. Syntheses of 16-substituted estradiol derivatives. Yiyao Gongye (1984), (8), 14-17.
Material Safety Data Sheet (MSDS)Not Available
General References
  1. Ohdoi C, Nyhan WL, Kuhara T: Chemical diagnosis of Lesch-Nyhan syndrome using gas chromatography-mass spectrometry detection. J Chromatogr B Analyt Technol Biomed Life Sci. 2003 Jul 15;792(1):123-30. [PubMed:12829005 ]
  2. Xu X, Veenstra TD, Fox SD, Roman JM, Issaq HJ, Falk R, Saavedra JE, Keefer LK, Ziegler RG: Measuring fifteen endogenous estrogens simultaneously in human urine by high-performance liquid chromatography-mass spectrometry. Anal Chem. 2005 Oct 15;77(20):6646-54. [PubMed:16223252 ]
  3. Xu X, Keefer LK, Waterhouse DJ, Saavedra JE, Veenstra TD, Ziegler RG: Measuring seven endogenous ketolic estrogens simultaneously in human urine by high-performance liquid chromatography-mass spectrometry. Anal Chem. 2004 Oct 1;76(19):5829-36. [PubMed:15456304 ]
  4. Weiss PA, Esterbauer HE, Scherr F: [Excretion of estriol, estetrol, 16-epi-estriol, 16-keto-estradiol and 16-hydroxyestrone in the 24-hour urine of pregnant women in the last trimester]. Endokrinologie. 1975 Aug;65(3):254-65. [PubMed:1222727 ]
  5. Xu X, Duncan AM, Merz-Demlow BE, Phipps WR, Kurzer MS: Menstrual cycle effects on urinary estrogen metabolites. J Clin Endocrinol Metab. 1999 Nov;84(11):3914-8. [PubMed:10566628 ]