Pyridoxal
Athanor · official
C8H9NO3 · 167.16 g/mol
IUPAC name: 3-hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carbaldehyde
Also called vitamin B6
WarningHarmful if swallowedNames and identifiers
- IUPAC name
- 3-hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carbaldehyde
- Synonyms
- vitamin B6, Pyridoxaldehyde, 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde
+ 36 more
3-hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carbaldehyde, Piridoxal, DTXSID4046020, 4-Pyridinecarboxaldehyde, 3-hydroxy-5-(hydroxymethyl)-2-methyl-, CHEBI:17310, 3THM379K8A, 3-hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridinecarboxaldehyde, 3-Hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carboxaldehyde, DTXCID2026020, 2-methyl-3-hydroxy-4-formyl-5-hydroxymethylpyridine, RefChem:177705, 200-630-8, MFCD00464806, EINECS 200-630-8, NSC 19613, 3-hydroxy-5-(hydroxymethyl)-2-methyl-pyridine-4-carbaldehyde, BRN 0383768, Oprea1_534980, 3-Hydroxy-5-hydroxymethyl-2-methyl-4-pyridincarbaldehyd, NCGC00142580-03, CAS-66-72-8, UNII-3THM379K8A, Pyridocalx, nchembio.93-comp2, PYRIDOXAL [MI], bmse000110, Epitope ID:549272, PYRIDOXAL [WHO-DD], SCHEMBL29906, 5-21-13-00044 (Beilstein Handbook Reference), MLS003876810, CHEMBL102970, orb1302584, orb1980180, orb2900418, orb3140055
- Molecular formula
- C8H9NO3
- Empirical formula
- C8H9NO3
- Molecular weight
- 167.16 g/mol
- Exact mass
- 167.05824
- CAS number
- 66-72-8
- PubChem CID
- 1050
- Canonical SMILES
- CC1=NC=C(C(=C1O)C=O)CO
- Isomeric SMILES
- CC1=NC=C(C(=C1O)C=O)CO
- InChI
- InChI=1S/C8H9NO3/c1-5-8(12)7(4-11)6(3-10)2-9-5/h2,4,10,12H,3H2,1H3
- InChIKey
- RADKZDMFGJYCBB-UHFFFAOYSA-N
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 12
- Rings
- 1
- Aromatic rings
- 1
- Fraction sp³ carbons (Fsp3)
- 0.25
- H-bond donors
- 2
- H-bond acceptors
- 4
- Rotatable bonds
- 2
- TPSA (Ų)
- 70.4
- Formal charge
- 0
- XLogP3
- 0 PubChem
- Complexity
- 162 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
- C57.48%
- H5.43%
- N8.38%
- O28.71%
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
- 0.4 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -1.37 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 2.71 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 167.16
- log P ≤ 5 (Crippen): 0.4
- H-bond donors ≤ 5: 2
- H-bond acceptors ≤ 10: 4
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: 39 company reports to ECHA. Source [1].
- Harmful or irritant
- H302Harmful if swallowed
Precautionary statements: P264, P270, P301+P317, P330, P501
Safety data sheets on the supplier’s page: Mcule, AKos Consulting & Solutions, ChemDiv.
Always read the supplier’s safety data sheet before working with it.
Spectra
- 1H NMRHuman Metabolome Database (HMDB) (Varian · 500 MHz · Water) · Human Metabolome Database (HMDB) (Bruker · D2O) · SpectraBase
- 13C NMRHuman Metabolome Database (HMDB) (Bruker · D2O) · SpectraBase
- 1H-13C NMRHuman Metabolome Database (HMDB) (Bruker · 600 MHz · Water)
- GC-MSHuman Metabolome Database (HMDB) (GC-MS) · Human Metabolome Database (HMDB) (GC-MS) · Human Metabolome Database (HMDB) (GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) · Positive) · Human Metabolome Database (HMDB) (GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) · Positive) · Human Metabolome Database (HMDB) (GC-EI-TOF (Pegasus III TOF-MS system, Leco; GC 6890, Agilent Technologies) · Positive) · MassBank of North America (MoNA) (GC-MS)
- MS-MSHuman Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Quattro_QQQ · Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (Positive) · Human Metabolome Database (HMDB) (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 (API3000, Applied Biosystems · LC-ESI-QQ · NEGATIVE) · MassBank Europe (API3000, Applied Biosystems · LC-ESI-QQ · NEGATIVE) · MassBank Europe (API3000, Applied Biosystems · LC-ESI-QQ · NEGATIVE)
- 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)
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
- [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
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.