Estradiol
Athanor · official
C18H24O2 · 272.4 g/mol
IUPAC name: (8R,9S,13S,14S,17S)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,17-diol
Also called oestradiol, E2, 17-beta-estradiol, Estrace, estrogen
DangerMay cause cancer · Suspected of causing cancer · May damage fertility or the unborn child · May damage fertility; May damage the unborn child · May cause harm to breast-fed children · Causes damage to organs through prolonged or repeated exposure · Very toxic to aquatic life · Very toxic to aquatic life with long lasting effectsNames and identifiers
- IUPAC name
- (8R,9S,13S,14S,17S)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,17-diol
- Synonyms
- oestradiol, E2, 17-beta-estradiol
+ 39 more
Estrace, estrogen, beta-Estradiol, 17beta-Estradiol, Oestradiol, Dihydrofolliculin, Aquadiol, Diogynets, Divigel, Vivelle, Diogyn, Dihydrotheelin, Dihydroxyestrin, Dimenformon, Estraderm, Femestral, Gynoestryl, Aerodiol, Climara, Gynergon, Vagifem, Estraldine, Estrogel, Evorel, Estring, Systen, Zumenon, estradiol-17beta, cis-Estradiol, Compudose, Innofem, Alora, Fempatch, Gynodiol, Ovocylin, Esclim, 17beta-Oestradiol, Elestrin, Evamist
- Molecular formula
- C18H24O2
- Empirical formula
- C9H12O
- Molecular weight
- 272.4 g/mol
- Exact mass
- 272.17763
- CAS number
- 50-28-2
- PubChem CID
- 5757
- Canonical SMILES
- CC12CCC3C(C1CCC2O)CCC4=C3C=CC(=C4)O
- Isomeric SMILES
- C[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@@H]2O)CCC4=C3C=CC(=C4)O
- InChI
- InChI=1S/C18H24O2/c1-18-9-8-14-13-5-3-12(19)10-11(13)2-4-15(14)16(18)6-7-17(18)20/h3,5,10,14-17,19-20H,2,4,6-9H2,1H3/t14-,15-,16+,17+,18+/m1/s1
- InChIKey
- VOXZDWNPVJITMN-ZBRFXRBCSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Physical properties
- Appearance
- White or slightly yellow, small crystals or crystalline powder[2]
2 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source – White powder. [1] Occupational Safety and Health Administration (OSHA) –shown White or slightly yellow, small crystals or crystalline powder [2] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 512 - Odor
- Odorless[2]
- Melting point
- 178-179 °C[1]
- Solubility in water
- In water, 3.90 mg/L at 27 °C[2]
- log P
- log Kow = 4.01 (B-estradiol)[2]
Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.
Calculated
- Heavy atoms
- 20
- Rings
- 4
- Aromatic rings
- 1
- Fraction sp³ carbons (Fsp3)
- 0.67
- H-bond donors
- 2
- H-bond acceptors
- 2
- Rotatable bonds
- 0
- TPSA (Ų)
- 40.5
- Formal charge
- 0
- XLogP3
- 4 PubChem
- Complexity
- 382 PubChem
- Stereocenters
- 5 definedCIP: C2: S · C5: S · C6: R · C16: S · C19: S
- Double-bond geometry
- None specified
- Point group
- C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C79.37%
- H8.88%
- O11.75%
Isotope pattern
Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.
Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.
Predicted
- log P
- 3.61 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -4.02 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 3.59 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 272.39
- log P ≤ 5 (Crippen): 3.61
- H-bond donors ≤ 5: 2
- H-bond acceptors ≤ 10: 2
Passes all four rules.
¹³C NMR shifts, predicted
Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.
Safety
Danger
Most widely reported: 159 company reports to ECHA. Source [3].
- Health hazard
- Environmental hazard
- H350May cause cancer (39.6% of reports)
- H351Suspected of causing cancer (57.9% of reports)
- H360May damage fertility or the unborn child (82.4% of reports)
- H360FDMay damage fertility; May damage the unborn child (11.9% of reports)
- H362May cause harm to breast-fed children (32.7% of reports)
- H372Causes damage to organs through prolonged or repeated exposure (34.6% of reports)
- H400Very toxic to aquatic life (30.8% of reports)
- H410Very toxic to aquatic life with long lasting effects (36.5% of reports)
Precautionary statements: P203, P260, P263, P264, P270, P273, P280, P318, P319, P391, P405, P501
Storage
Incompatibilities
- A carcinogen.[2]
Safety data sheets on the supplier’s page: A2B Chem, LGC Standards, Alfa Chemistry.
Always read the supplier’s safety data sheet before working with it.
Spectra
- 1H NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · 100%_DMSO) · SpectraBase (Varian CFT-20)
- 13C NMRSpectraBase
- 1H-13C NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · 100%_DMSO)
- GC-MSHuman Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (EI-B · positive) · Human Metabolome Database (HMDB) (GC-MS) · Human Metabolome Database (HMDB) (GC-MS)
- MS-MSHuman Metabolome Database (HMDB) (Negative) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive)
- LC-MSMassBank Europe (Exploris 480 Orbitrap (Thermo Scientific) · LC-ESI-QFT · NEGATIVE) · MassBank Europe (Agilent 6560 QTOF · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (Agilent 6560 QTOF · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (Agilent 6560 QTOF · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Bruker maXis Impact · LC-ESI-QTOF · POSITIVE)
- Other MSHazardous Substances Data Bank (HSDB) · MassBank Europe (JEOL JMS-01-SG-2 · EI-B · POSITIVE) · MassBank Europe (HITACHI RMU-6E · EI-B · POSITIVE) · MassBank Europe (HITACHI M-52 · EI-B · POSITIVE) · MassBank Europe (HITACHI M-80 · EI-B · POSITIVE) · MassBank of North America (MoNA) (positive)
- UVHazardous Substances Data Bank (HSDB)
- IRHazardous Substances Data Bank (HSDB)
- FTIRSpectraBase (KBr WAFER)
- ATR-IRSpectraBase (Bio-Rad FTS · ATR-Neat (DuraSamplIR II))
- RamanSpectraBase (FT-Raman)
Experimental spectra held by these sources; each link opens the source's own record.
Literature
Reading PubChem, OpenAlex and GSRS…
Bioactivity
Reading ChEMBL…
References
- [1]Occupational Safety and Health Administration (OSHA) · Public domain (US DOL) · via PubChem · retrieved 2026-10-14
- [2]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
- [3]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [4]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [5]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [6]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
- [7]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [8]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.