Estriol
Athanor · official
C18H24O3 · 288.4 g/mol
IUPAC name: (8R,9S,13S,14S,16S,17R)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,16,17-triol
Also called E3, oestriol, pregnancy estrogen
DangerMay cause cancer · May damage fertility or the unborn child · Causes damage to organs through prolonged or repeated exposureNames and identifiers
- IUPAC name
- (8R,9S,13S,14S,16S,17R)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,16,17-triol
- Synonyms
- E3, oestriol, pregnancy estrogen
+ 39 more
16-Epiestriol, Epiestriol, Epioestriol, Epiestriolum, Epioestriolum, Epiestriolo, (8R,9S,13S,14S,16S,17R)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta[a]phenanthrene-3,16,17-triol, NSC-26646, 8XZ32LI44K, Estra-1,3,5(10)-triene-3,16beta,17beta-triol, NSC-758892, (8R,9S,13S,14S,16S,17R)-13-methyl-6,7,8,9,11,12,14,15,16,17-decahydrocyclopenta(a)phenanthrene-3,16,17-triol, RefChem:590931, 208-937-9, Actriol, Estriol EP Impurity F, 16-epi-Estriol, 16b-hydroxyestradiol, 16-Epiestratriol, 16beta-Hydroxyestradiol, 16b,17b-Estriol, (8R,9S,13S,14S,16S,17R)-13-methyl-7,8,9,11,12,13,14,15,16,17-decahydro-6H-cyclopenta[a]phenanthrene-3,16,17-triol, CHEBI:87620, MFCD00067609, Estra-1,3.5(10)-triene-3,16beta,17beta-triol, Estriol Impurity F, Epiestriol [INN], 3,17.beta.-Estriol, Epiestriolo [DCIT], Epiestriol [INN:BAN], Epiestriolum [INN-Latin], UNII-8XZ32LI44K, 16-Epiestriol, Ultra Pure (contains less than 0.3% Estriol), 16-epioestriol, EINECS 208-937-9, 16beta,17beta-Estriol, 16.beta.-Hydroxyestradiol, Estriol (3,17.beta.), (16|A,17|A)-Estra-1,3,5(10)-triene-3,16,17-triol
- Molecular formula
- C18H24O3
- Empirical formula
- C6H8O
- Molecular weight
- 288.4 g/mol
- Exact mass
- 288.17254
- CAS number
- 50-27-1
- PubChem CID
- 68929
- Canonical SMILES
- CC12CCC3C(C1CC(C2O)O)CCC4=C3C=CC(=C4)O
- Isomeric SMILES
- C[C@]12CC[C@H]3[C@H]([C@@H]1C[C@@H]([C@@H]2O)O)CCC4=C3C=CC(=C4)O
- InChI
- InChI=1S/C18H24O3/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/h3,5,8,13-17,19-21H,2,4,6-7,9H2,1H3/t13-,14-,15+,16+,17+,18+/m1/s1
- InChIKey
- PROQIPRRNZUXQM-ZMSHIADSSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 21
- Rings
- 4
- Aromatic rings
- 1
- Fraction sp³ carbons (Fsp3)
- 0.67
- H-bond donors
- 3
- H-bond acceptors
- 3
- Rotatable bonds
- 0
- TPSA (Ų)
- 60.7
- Formal charge
- 0
- XLogP3
- 2.5 PubChem
- Complexity
- 411 PubChem
- Stereocenters
- 6 definedCIP: C2: S · C5: S · C6: R · C16: S · C18: S · C20: R
- 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
- C74.97%
- H8.39%
- O16.64%
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
- 2.58 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -3.46 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 3.87 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 288.39
- log P ≤ 5 (Crippen): 2.58
- H-bond donors ≤ 5: 3
- H-bond acceptors ≤ 10: 3
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: 2 company reports to ECHA. Source [1].
- Health hazard
- H350May cause cancer (50% of reports)
- H360May damage fertility or the unborn child
- H372Causes damage to organs through prolonged or repeated exposure (50% of reports)
Precautionary statements: P203, P260, P264, P270, P280, P318, P319, P405, P501
Safety data sheets on the supplier’s page: LGC Standards, Xianglong Pharmaceutical Standards (XL Standards), Pharmacore Co., Limited.
Always read the supplier’s safety data sheet before working with it.
Spectra
- 1H NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · Water)
- 1H-13C NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · 100%_DMSO)
- GC-MSSpectraBase
- LC-MSMassBank of North America (MoNA) (Quattro_QQQ · positive) · MassBank of North America (MoNA) (Quattro_QQQ · positive) · MassBank of North America (MoNA) (Quattro_QQQ · positive)
- FTIRSpectraBase (Bio-Rad FTS · KBr1 1.00mg)
- 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]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
- [2]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [3]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [4]MassBank of North America (MoNA) · CC BY 4.0 · 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.