Human Metabolome Database Version 3.5

Showing metabocard for 4-Pyridoxic acid (HMDB00017)

Record Information
Version 3.5
Creation Date 2005-11-16 08:48:42 -0700
Update Date 2013-02-08 17:07:45 -0700
Secondary Accession Numbers None
Metabolite Identification
Common Name 4-Pyridoxic acid
Description 4-Pyridoxic acid is the catabolic product of vitamin B6 (also known as pyridoxine, pyridoxal and pyradoxamine) which is excreted in the urine. Urinary levels of 4-pyridoxic acid are lower in females than in males and will be reduced in persons with riboflavin deficiency. 4-Pyridoxic acid is formed by the action of aldehyde oxidase I (an endogenous enzyme) and by microbial enzymes (pyridoxal 4-dehydrogenase), an NAD-dependent aldehyde dehydrogenase. 4-pyridoxic acid can be further broken down by the gut microflora via 4-pyridoxic acid dehydrogenase. This enzyme catalyzes the four electron oxidation of 4-pyridoxic acid to 3-hydroxy-2-methylpyridine-4,5-dicarboxylate, using nicotinamide adenine dinucleotide as a cofactor.
Structure Thumb
Download: MOL | SDF | PDB | SMILES | InChI
Display: 2D Structure | 3D Structure
  1. 2-Methyl-3-hydroxy-4-carboxy-5-hydroxymethylpyridine
  2. 3-Hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridinecarboxylate
  3. 3-Hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridinecarboxylic acid
  4. 3-Hydroxy-5-(hydroxymethyl)-2-methyl-Isonicotinate
  5. 3-Hydroxy-5-(hydroxymethyl)-2-methyl-Isonicotinic acid
  6. 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinate
  7. 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinic acid
  8. 3-Hydroxy-5-hydroxymethyl-2-methyl-isonicotinate
  9. 3-Hydroxy-5-hydroxymethyl-2-methyl-isonicotinic acid
  10. 3-Hydroxy-5-hydroxymethyl-2-methyl-isonicotinsaeure
  11. 4-Pyridoxate
  12. 4-Pyridoxinate
  13. 4-Pyridoxinecarboxylate
  14. 4-Pyridoxinecarboxylic acid
  15. 4-Pyridoxinic acid
  16. 4-Pyridoxinsaeure
  17. 4-Pyridoxylate
  18. 4-Pyridoxylic acid
Chemical Formula C8H9NO4
Average Molecular Weight 183.1614
Monoisotopic Molecular Weight 183.053157781
IUPAC Name 3-hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carboxylic acid
Traditional IUPAC Name pyridoxic acid
CAS Registry Number 82-82-6
InChI Identifier InChI=1S/C8H9NO4/c1-4-7(11)6(8(12)13)5(3-10)2-9-4/h2,10-11H,3H2,1H3,(H,12,13)
Chemical Taxonomy
Kingdom Organic Compounds
Super Class Aromatic Heteromonocyclic Compounds
Class Pyridines and Derivatives
Sub Class Pyridinecarboxylic Acids and Derivatives
Other Descriptors
  • Pyridines and Derivatives
  • hydroxymethylpyridine(ChEBI)
  • methylpyridines(ChEBI)
  • monohydroxypyridine(ChEBI)
  • vitamin B6(ChEBI)
  • Carboxylic Acid
  • Primary Alcohol
Direct Parent Pyridinecarboxylic Acids and Derivatives
Status Detected and Quantified
  • Endogenous
Biofunction Not Available
Application Not Available
Cellular locations
  • Cytoplasm
  • Extracellular
Physical Properties
State Solid
Experimental Properties
Property Value Reference
Melting Point 247 - 248 °C Not Available
Boiling Point Not Available Not Available
Water Solubility Not Available Not Available
LogP Not Available Not Available
Predicted Properties
Property Value Source
Water Solubility 8.71 g/L ALOGPS
LogP -0.08 ALOGPS
LogP -0.75 ChemAxon
LogS -1.32 ALOGPS
pKa (strongest acidic) 2.55 ChemAxon
pKa (strongest basic) 4.09 ChemAxon
Hydrogen Acceptor Count 5 ChemAxon
Hydrogen Donor Count 3 ChemAxon
Polar Surface Area 90.65 A2 ChemAxon
Rotatable Bond Count 2 ChemAxon
Refractivity 44.55 ChemAxon
Polarizability 17.19 ChemAxon
Formal Charge 0 ChemAxon
Physiological Charge -1 ChemAxon
1H NMR Spectrum
MS/MS Spectrum LC-ESI-QQ (API3000, Applied Biosystems) 10
MS/MS Spectrum LC-ESI-QQ (API3000, Applied Biosystems) 20
MS/MS Spectrum LC-ESI-QQ (API3000, Applied Biosystems) 30
MS/MS Spectrum LC-ESI-QQ (API3000, Applied Biosystems) 40
MS/MS Spectrum LC-ESI-QQ (API3000, Applied Biosystems) 50
MS/MS Spectrum LC-ESI-QTOF (UPLC Q-Tof Premier, Waters)
MS/MS Spectrum LC-ESI-QTOF (UPLC Q-Tof Premier, Waters) 30
MS/MS Spectrum LC-ESI-QTOF (UPLC Q-Tof Premier, Waters)
MS/MS Spectrum GC-MS
[1H,13C] 2D NMR Spectrum
Biological Properties
Cellular Locations
  • Cytoplasm
  • Extracellular
Biofluid Locations
  • Blood
  • Urine
Tissue Location
  • Bladder
  • Erythrocyte
  • Kidney
  • Liver
Name SMPDB Link KEGG Link
Vitamin B6 Metabolism SMP00017 map00750 Link_out
Normal Concentrations
Biofluid Status Value Age Sex Condition Reference
Blood Detected and Quantified
0.027 (0.0062-3.14) uM Adult (>18 years old) Both Normal
Blood Detected and Quantified
0.040 +/- 0.007 uM Adult (>18 years old) Both Normal
  • Geigy Scient...
Blood Detected and Quantified
0.0071 +/- 0.005 uM Adult (>18 years old) Female Normal
Blood Detected and Quantified
0.0097 +/- 0.00665 uM Adult (>18 years old) Male Normal
Urine Detected and Quantified
> 0.33 umol/mmol creatinine Adult (>18 years old) Female Normal
Urine Detected and Quantified
0.78 +/- 0.45 umol/mmol creatinine Adult (>18 years old) Both Comment Normal
Urine Detected and Quantified
3.1 (0.4-7.5) umol/mmol creatinine Adult (>18 years old) Both Comment Normal
Urine Detected and Quantified
> 3.0 umol/mmol creatinine Children (1-13 year old) Both Normal
Urine Detected and Quantified
2.99 +/- 5.25 umol/mmol creatinine Infant (0-1 year old) Both Normal
Abnormal Concentrations
Biofluid Status Value Age Sex Condition Reference
Urine Detected and Quantified 1414.9 +/- 737.8 umol/mmol creatinine Adult (>18 years old) Both Comment Critically ill
Associated Disorders and Diseases
Disease References None
Associated OMIM IDs None
DrugBank ID Not Available
DrugBank Metabolite ID Not Available
Phenol Explorer Compound ID Not Available
Phenol Explorer Metabolite ID Not Available
FoodDB ID FDB021874
KNApSAcK ID Not Available
Chemspider ID 6467 Link_out
KEGG Compound ID C00847 Link_out
BioCyc ID CPD-1112 Link_out
BiGG ID 36190 Link_out
Wikipedia Link Not Available
NuGOwiki Link HMDB00017 Link_out
Metagene Link HMDB00017 Link_out
METLIN ID 239 Link_out
PubChem Compound 6723 Link_out
PDB ID Not Available
ChEBI ID 17405 Link_out
Synthesis Reference Senkuma, Masahiko; Imada, Katsumi; Sato, Masatada. Preparation of 4-pyridoxic acid. Jpn. Kokai Tokkyo Koho (1992), 2 pp.
Material Safety Data Sheet (MSDS) Download (PDF)
General References
  1. Huang YC, Lan PH, Cheng CH, Lee BJ, Kan MN: Vitamin B6 intakes and status of mechanically ventilated critically ill patients in Taiwan. Eur J Clin Nutr. 2002 May;56(5):387-92. Pubmed: 12001008 Link_out
  2. Kodentsova VM, Vrzhesinskaia OA, Sokol'nikov AA, Beketova NA, Spirichev VB: [The effect of riboflavin supply on metabolism of water-soluble vitamins] Vopr Med Khim. 1993 Sep-Oct;39(5):29-33. Pubmed: 8279138 Link_out
  3. Masse PG, Mahuren JD, Tranchant C, Dosy J: B-6 vitamers and 4-pyridoxic acid in the plasma, erythrocytes, and urine of postmenopausal women. Am J Clin Nutr. 2004 Oct;80(4):946-51. Pubmed: 15447904 Link_out
  4. Huang YC, Chang HH, Huang SC, Cheng CH, Lee BJ, Cheng SY, Su KH: Plasma pyridoxal 5'-phosphate is a significant indicator of immune responses in the mechanically ventilated critically ill. Nutrition. 2005 Jul-Aug;21(7-8):779-85. Pubmed: 15975484 Link_out
  5. Ericson KL, Mahuren JD, Zubovic YM, Coburn SP: Use of chlorite to improve HPLC detection of pyridoxal 5'-phosphate. J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Sep 5;823(2):218-20. Pubmed: 16054880 Link_out
  6. Driskell JA, Chrisley BM: Plasma B-6 vitamer and plasma and urinary 4-pyridoxic acid concentrations in young women as determined using high performance liquid chromatography. Biomed Chromatogr. 1991 Sep;5(5):198-201. Pubmed: 1742549 Link_out
  7. Chiang EP, Smith DE, Selhub J, Dallal G, Wang YC, Roubenoff R: Inflammation causes tissue-specific depletion of vitamin B6. Arthritis Res Ther. 2005;7(6):R1254-62. Epub 2005 Sep 13. Pubmed: 16277678 Link_out
  8. Rybak ME, Pfeiffer CM: Clinical analysis of vitamin B(6): determination of pyridoxal 5'-phosphate and 4-pyridoxic acid in human serum by reversed-phase high-performance liquid chromatography with chlorite postcolumn derivatization. Anal Biochem. 2004 Oct 15;333(2):336-44. Pubmed: 15450810 Link_out
  9. Huang YC, Chang SJ, Chiu YT, Chang HH, Cheng CH: The status of plasma homocysteine and related B-vitamins in healthy young vegetarians and nonvegetarians. Eur J Nutr. 2003 Apr;42(2):84-90. Pubmed: 12638029 Link_out
  10. Midttun O, Hustad S, Solheim E, Schneede J, Ueland PM: Multianalyte quantification of vitamin B6 and B2 species in the nanomolar range in human plasma by liquid chromatography-tandem mass spectrometry. Clin Chem. 2005 Jul;51(7):1206-16. Pubmed: 15976101 Link_out
  11. Chang SJ, Huang YC, Hsiao LJ, Lee YC, Hsuen SY: Determination of vitamin B-6 estimated average requirement and recommended dietary allowance for children aged 7-12 years using vitamin B-6 intake, nutritional status and anthropometry. J Nutr. 2002 Oct;132(10):3130-4. Pubmed: 12368406 Link_out

Name: Aldehyde oxidase
Pyridoxal + Oxygen + Water unknown 4-Pyridoxic acid + Hydrogen peroxide details
Gene Name: AOX1
Uniprot ID: Q06278 Link_out
Protein Sequence: FASTA
Gene Sequence: FASTA