Pterin
Athanor · official
C6H5N5O · 163.14 g/mol
IUPAC name: 2-amino-3H-pteridin-4-one
Also called 2-aminopteridin-4-one, pteridine pigment, folate core
WarningCauses skin irritation · Causes serious eye irritation · May cause respiratory irritationNames and identifiers
- IUPAC name
- 2-amino-3H-pteridin-4-one
- Synonyms
- 2-aminopteridin-4-one, pteridine pigment, folate core
+ 37 more
2-Amino-4-hydroxypteridine, Pteridoxamine, 4-Oxopterin, 2-Amino-4-pteridone, 2-Amino-4(1H)-pteridinone, NSC-18696, 2-amino-3H-pteridin-4-one, 85MA24E1NH, DTXSID40176894, NSC-11540, NSC-170929, 2-amino-3,4-dihydropteridin-4-one, RefChem:464305, DTXCID3099385, CHEBI:26374, CHEBI:73184, 218-799-1, Pterine, 2-aminopteridin-4-ol, 2-aminopteridin-4(3H)-one, 2-Amino-1H-pteridin-4-one, 2-Amino-4-oxopteridine, 2-Amino-4(3H)-pteridinone, 4(1H)-Pteridinone, 2-amino-, 2-AMINO-4-HYDROXY-PTERIDINE, 2-aminopteridin-4(1H)-one, 2-Amino-4-pteridinol, Quinonoid dihydropterin, 2-amino-, MFCD01456481, NSC 18696, 2-desaminoaminopterin, 2-Aminopteridin-4-one, NSC 11540, NSC 170929, UNII-85MA24E1NH, 2-DESAMINO-AMINOPTERIN, CHEMBL278009
- Molecular formula
- C6H5N5O
- Empirical formula
- C6H5N5O
- Molecular weight
- 163.14 g/mol
- Exact mass
- 163.04941
- CAS number
- 2236-60-4
- PubChem CID
- 135398660
- Canonical SMILES
- C1=CN=C2C(=N1)C(=O)NC(=N2)N
- Isomeric SMILES
- C1=CN=C2C(=N1)C(=O)NC(=N2)N
- InChI
- InChI=1S/C6H5N5O/c7-6-10-4-3(5(12)11-6)8-1-2-9-4/h1-2H,(H3,7,9,10,11,12)
- InChIKey
- HNXQXTQTPAJEJL-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 12
- Rings
- 2
- Aromatic rings
- 2
- Fraction sp³ carbons (Fsp3)
- 0
- H-bond donors
- 2
- H-bond acceptors
- 5 computed here · PubChem 4
- Rotatable bonds
- 0
- TPSA (Ų)
- 97.5 computed here · PubChem 93.3
- Formal charge
- 0
- XLogP3
- -1.4 PubChem
- Complexity
- 238 PubChem
- Stereocenters
- None
- 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
- C44.17%
- H3.09%
- N42.93%
- O9.81%
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
- -0.7 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -1.02 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 2.7 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 163.14
- log P ≤ 5 (Crippen): -0.7
- H-bond donors ≤ 5: 2
- H-bond acceptors ≤ 10: 5
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
Warning
Most widely reported: 38 company reports to ECHA. Source [1].
- Harmful or irritant
- H315Causes skin irritation
- H319Causes serious eye irritation
- H335May cause respiratory irritation
Precautionary statements: P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501
Safety data sheets on the supplier’s page: AstaTech, Inc., Smolecule, Combi-Blocks.
Always read the supplier’s safety data sheet before working with it.
Spectra
- NMRNMRShiftDB
- 1H NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · 100%_DMSO)
- 13C NMRSpectraBase
- 1H-13C NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · 100%_DMSO)
- GC-MSNIST Mass Spectrometry Data Center · SpectraBase
- MS-MSHuman Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive)
- LC-MSMassBank Europe (Agilent 6530 QTOF · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Agilent 6530 QTOF · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Agilent 6530 QTOF · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Agilent 6530 Q-TOF LC/MS · LC-ESI-QTOF · NEGATIVE) · MassBank Europe (Agilent 6530 Q-TOF LC/MS · LC-ESI-QTOF · POSITIVE) · MassBank Europe (Agilent 6530 Q-TOF LC/MS · LC-ESI-QTOF · POSITIVE)
- Other MSMassBank of North America (MoNA) (TQD, Waters · Flow-injection QqQ/MS · ESI) · MassBank of North America (MoNA) (TQD, Waters · Flow-injection QqQ/MS · ESI) · MassBank of North America (MoNA) (TQD, Waters · Flow-injection QqQ/MS · ESI)
- FTIRSpectraBase (KBr WAFER)
- ATR-IRSpectraBase
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]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
- [3]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
- [4]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [5]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
- [6]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
- [7]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.