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

What is the Entecavir?

The molecule Entecavir presents a molecular formula of C12H15N5O3 and its IUPAC name is 2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-1H-purin-6-one.

Entecavir is a nucleoside analog antiviral medication used to treat hepatitis B virus (HBV) infection. It is sold under the brand names Baraclude and Entavir. .

Chemically, entecavir is a guanosine analog and lies as a nucleoside reverse transcriptase inhibitor (NRTI). It works by blocking the activity of the HBV enzyme known as reverse transcriptase. This prevents the virus from making copies of itself and spreading. .

Entecavir was first approved for use in the United States in 2005. It is also approved for use in other countries, including Canada, Japan, and several countries in Europe. .

Clinical studies have shown that entecavir behaves reducing the levels of HBV in the blood and improving liver function. It is generally well-tolerated, with the most common side effects being headache and fatigue. .

Entecavir is typically used as a long-term treatment for HBV. It is important to continue taking the medication even if you feel well, as stopping treatment can lead to the virus becoming resistant to entecavir and other antiviral medications..

3D structure

Cartesian coordinates

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

2D drawing


Entecavir QDGZDCVAUDNJFG-FXQIFTODSA-N chemical compound 2D structure molecule svg


Molecule descriptors

IUPAC name2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-1H-purin-6-one
InChI codeInChI=1S/C12H15N5O3/c1-5-6(3-18)8(19)2-7(5)17-4-14-9-10(17)15-12(13)16-11(9)20/h4,6-8,18-19H,1-3H2,(H3,13,15,16,20)/t6-,7-,8-/m0/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.

  • (1R,3S,4S)-Entecavir
  • 1333204-94-6
  • 142217-69-4
  • 188399-46-4
  • 2-Amino-9-[(1S,3R,4S)-4-hydroxy-3-hydroxymethyl-2-methylene-cyclopentyl]-3,9-dihydro-purin-6-one
  • 2-Amino-9-[(1S,3R,4S)-4-hydroxy-3-hydroxymethyl-2-methylenecyclopentyl]-1,9-dihydro-6H-purin-6-one
  • 2-amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one
  • 2-amino-9-((1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl)-1,9-dihydro-6H-purin-6-one
  • 2-amino-9-[(1R,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylene-cyclopentyl]-3H-purin-6-one hydrate;Entecavir
  • 2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylene-cyclopentyl]-1H-purin-6-one
  • 2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-1,9-dihydro-6H-purin-6-one
  • 2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-1,9-dihydro-6H-purin-6-one hydrate (1:1)
  • 2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-1H-purin-6-one
  • 2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-3H-purin-6-one
  • 2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-6,9-dihydro-3H-purin-6-one
  • 2-amino-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-1,9-dihydro-6H-purin-6-one
  • 217E694
  • 6-H-Purin-6-one-,2-amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]
  • 6H-Purin-6-one, 2-amino-1,9-dihydro-9-((1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl)-
  • 6H-Purin-6-one, 2-amino-1,9-dihydro-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-
  • 9-[(1S,3R,4S)-4-Hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]guanine
  • A807868
  • AC-1593
  • AM20080880
  • AR-270/43507901
  • BDBM50248008
  • BMS 200475
  • BMS-200475
  • BMS-200475-01
  • BMS200475
  • Baraclude
  • CCG-267218
  • CS-3160
  • D07896
  • DB00442
  • DSSTox_CID_26446
  • DSSTox_GSID_46446
  • DSSTox_RID_81621
  • E0899
  • Entecavir
  • Entecavir (INN)
  • Entecavir anhydrous
  • GS-6386
  • HSDB 7334
  • HY-13623
  • LS41110
  • MFCD00907887
  • NCGC00164563-01
  • NCGC00164563-04
  • NCGC00164563-06
  • NCGC00164563-09
  • NCGC00164563-13
  • NNU2O4609D
  • Q418586
  • S5246
  • SQ 34,676
  • SQ 34676
  • SQ-34676
  • SQ34676
  • anhydrous entecavir
  • entecavir (anhydrous)

Reference codes for other databases

There exist several different chemical codes commonly used in orded to identify molecules:
  • ZINC3802690
  • CAS-142217-69-4
  • UNII-NNU2O4609D
  • AKOS015854916
  • AKOS015920226
  • AKOS025312554
  • BRD-K08206212-001-01-2
  • DTXSID4046446
  • CHEMBL713
  • CHEBI:473990
  • Tox21_112192
  • SCHEMBL28648
  • SCHEMBL15198001

Physico-Chemical properties

IUPAC name2-amino-9-[(1S,3R,4S)-4-hydroxy-3-(hydroxymethyl)-2-methylidenecyclopentyl]-1H-purin-6-one
Molecular formulaC12H15N5O3
Molecular weight277.279
Melting point (ºC)
Boiling point (ºC)
Density (g/cm3)
Molar refractivity72.39
Topological polar surface area130.1

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.