A summary of the most common chemical descriptors (InChI Key and SMILES codes) for Equilin are summarized together with 3D and 2D structures and relevant physico-chemical properties.

What is the Equilin?

The molecule Equilin presents a molecular formula of C18H20O2 and its IUPAC name is (9S,13S,14S)-3-hydroxy-13-methyl-9,11,12,14,15,16-hexahydro-6H-cyclopenta[a]phenanthren-17-one.

Equilin is a molecule that belongs to the class of compounds known as estrogens. It belongs naturally in the urine of pregnant horses and is also produced artificially in the laboratory. Equilin is structurally similar to the human estrogen hormone estradiol and has a similar biological activity..

Equilin is used in a number of medical and non-medical applications. In medicine, it is used as a hormone replacement therapy in women who have low estrogen levels due to menopause, surgical removal of the ovaries, or other conditions. It is available in a variety of formulations, including oral tablets, transdermal patches, and vaginal creams and rings..

Equilin is also used in the production of certain medications, including conjugated estrogens, which are used to treat menopausal symptoms and prevent osteoporosis (a condition that weakens the bones). It is also used in the production of certain veterinary medications, such as estrogens for the treatment of estrogen-responsive conditions in animals..

In non-medical applications, equilin is used as a performance-enhancing substance in sports. It is banned by most sporting organizations due to its potential to improve athletic performance and give an unfair advantage to users..

Equilin can have side effects, including nausea, vomiting, bloating, breast tenderness, and changes in mood and behavior. It can also increase the risk of certain health problems, such as blood clots, heart attack, stroke, and breast cancer. It is important to discuss the risks and benefits of equilin with a healthcare provider before starting treatment..


From all the above, this molecule is a molecule that is structurally similar to the human estrogen hormone estradiol and has a similar biological activity. It is used in a number of medical and non-medical applications, including hormone replacement therapy and the production of certain medications and veterinary products. Equilin can have side effects and may increase the risk of certain health problems, and it is important to discuss the risks and benefits with a healthcare provider before starting treatment..

3D structure

Cartesian coordinates

Geometry of Equilin in x, y and z coordinates (Å units) to copy/paste elsewhere. Generated with Open Babel software.

2D drawing


Equilin WKRLQDKEXYKHJB-HFTRVMKXSA-N chemical compound 2D structure molecule svg


Molecule descriptors

IUPAC name(9S,13S,14S)-3-hydroxy-13-methyl-9,11,12,14,15,16-hexahydro-6H-cyclopenta[a]phenanthren-17-one
InChI codeInChI=1S/C18H20O2/c1-18-9-8-14-13-5-3-12(19)10-11(13)2-4-15(14)16(18)6-7-17(18)20/h3-5,10,14,16,19H,2,6-9H2,1H3/t14-,16+,18+/m1/s1

Other names (synonyms)

IUPAC nomenclature provides a standardized method for naming chemical compounds. Although this system is widely used in chemistry, many chemical compounds have also other names commonly used in different contexts. These synonyms can come from a variety of sources and are used for a variety of purposes.

One common source of synonyms for chemical compounds is the common or trivial names, assigned on the basis of appearance, properties, or origin of the molecule.

Another source of synonyms are historical or obsolete names employed in the past, however replaced nowadays by more modern or standardized names.

In addition to common and historical names, chemical compounds may also have synonyms that are specific to a particular field or industry.

  • (9S,13S,14S)-3-hydroxy-13-methyl-9,11,12,13,15,16-hexahydro-6H-cyclopenta[a]phenanthren-17(14H)-one
  • (9S,13S,14S)-3-hydroxy-13-methyl-9,11,12,14,15,16-hexahydro-6H-cyclopenta[a]phenanthren-17-one
  • 08O86EX0J4
  • 1,3,5,7-Estratetraen-3-ol-17-one
  • 1,5,7-Estratetraen-3-ol-17-one
  • 3-HYDROXYESTRA-1,3,5(10),7-TETRAEN-17-ONE
  • 3-Hydroxyestra-1,5(10),7-tetraen-17-one
  • 3-Hydroxyoestra-1,3,5(10),7-tetraen-17-one
  • 3-hydroxy-estra-1,3,5(10), 7-tetraen-17-one
  • 3-hydroxy-estra-1,3,5(10),7-tetraen-17-one
  • 3-hydroxy-estra-1,3,5(10),7tetraen-17-one
  • 474-86-2
  • 7-Dehydroestrone
  • BDBM50423544
  • BPBio1_000923
  • BRN 2624302
  • BSPBio_000839
  • CCG-220850
  • CCRIS 9074
  • CS-4786
  • D04041
  • DB02187
  • DSSTox_CID_27433
  • DSSTox_GSID_47433
  • DSSTox_RID_82343
  • Dihydroequilenin
  • Equilin
  • Equilin; 7-Dehydroestrone; 3-Hydroxy-1,3,5(10),7-estratetraen-17-one; 1,3,5(10),7-Estratetraen-3-ol-17-one
  • Estra-1,3,5(10),7-tetraen-17-one, 3-hydroxy-
  • Estra-1,5(10),7-tetraen-17-one, 3-hydroxy-
  • HMS1570J21
  • HMS2097J21
  • HMS2233A16
  • HMS3714J21
  • HY-B1176
  • LMST02010026
  • MLS000028624
  • MLS001148117
  • NCGC00179406-01
  • NCGC00256728-01
  • NSC 10971
  • NSC-10971
  • NSC10971
  • Opera_ID_780
  • Prestwick0_000850
  • Prestwick1_000850
  • Prestwick2_000850
  • Prestwick3_000850
  • Prestwick_219
  • Q5384492
  • S00287
  • SMR000058656
  • SR-01000721841
  • SR-01000721841-2
  • WLN: L E5 B666 FV JUTTT&J E1 OQ
  • equilin

Reference codes for other databases

There exist several different chemical codes commonly used in orded to identify molecules:
  • ZINC100031739
  • CAS-474-86-2
  • UNII-08O86EX0J4
  • AKOS024285096
  • BRD-K04046242-001-03-6
  • DTXSID7047433
  • CHEMBL323533
  • CHEBI:42309
  • Tox21_302641
  • EINECS 207-488-6
  • SPBio_002760
  • SCHEMBL124758

Physico-Chemical properties

IUPAC name(9S,13S,14S)-3-hydroxy-13-methyl-9,11,12,14,15,16-hexahydro-6H-cyclopenta[a]phenanthren-17-one
Molecular formulaC18H20O2
Molecular weight268.35
Melting point (ºC)
Boiling point (ºC)
Density (g/cm3)
Molar refractivity79.59
Topological polar surface area37.3

LogP and topological polar surface area (TPSA) values were estimated using Open Babel software.

The n-octanol/water partition coeficient (Kow) data is applied in toxicology and drug research. Kow values are used, to guess the environmental fate of persistent organic pollutants. High partition coefficients values, tend to accumulate in the fatty tissue of organisms. Molecules with a log(Kow) (or LogP) greater than 5 are considered to bioaccumulate.

TPSA values are the sum of the surface area over all polar atoms or molecules, mainly oxygen and nitrogen, also including hydrogen atoms.

In medicinal chemistry, TPSA is used to assess the ability of a drug to permeabilise cells.

For molecules to penetrate the blood-brain barrier (and act on receptors in the central nervous system), TPSA values below 90 Å2 are required. Thus, molecules with a polar surface area greater than 140 Å2 tend to be poorly permeable to cell membranes.