4-Pyridoxic acid

Synonym(s):2-Methyl-3-hydroxy-4-carboxy-5-hydroxymethylpyridine;3-Hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridinecarboxylic acid

CAS NO.：82-82-6
Empirical Formula: C8H9NO4
Molecular Weight: 183.16
MDL number: MFCD00006334
EINECS: 201-440-8
SAFETY DATA SHEET (SDS)
Update Date: 2026-04-24 14:58:28

What is 4-Pyridoxic acid?

The Uses of 4-Pyridoxic acid

4-Pyridoxic Acid, a catabolite of vitamin B6 (P991735), is a water-soluble B-group vitamin that can be used as a urinary diagnostic biomarker for determining the nutritional status of these vitamins.

What are the applications of Application

4-Pyridoxic acid is a catabolite of vitamin B6

Definition

ChEBI: 4-pyridoxic acid is a methylpyridine that is 2-methylpyridine substituted by a hydroxy group at C-3, a carboxy group at C-4, and a hydroxymethyl group at C-5. It is the catabolic product of vitamin B6 and is excreted in the urine. It has a role as a mouse metabolite and a human urinary metabolite. It is a member of methylpyridines, a hydroxymethylpyridine, a monohydroxypyridine and a vitamin B6. It is functionally related to an isonicotinic acid. It is a conjugate acid of a 4-pyridoxate.

Synthesis Reference(s)

Journal of Heterocyclic Chemistry, 4, p. 625, 1967 DOI: 10.1002/jhet.5570040427

Enzyme inhibitor

This oxidized derivative (FW = 171.15 g/mol) of pyridoxal is the chief catabolic product of pyridoxine, pyridoxal, and pyridoxamine degradation; it can be isolated from human urine. The carboxyl group has a pKa value of 5.50 while the phenolic OH has a value of 9.75. 4-Pyridoxic acid has a blue fluorescence which is maximal between pH 3 and 4. Heating 4-pyridoxic acid in 0.5 N acid will convert the metabolite to its lactone, which has an even stronger fluorescence. Target(s): dextransucrase; glucose dehydrogenase; pyridoxal dehydrogenase; and pyridoxaminephosphate oxidase.

Properties of 4-Pyridoxic acid

Melting point:	258-261 °C (dec.) (lit.)
Boiling point:	584.5±50.0 °C(Predicted)
Density	1.480±0.06 g/cm3(Predicted)
storage temp.	-20°C
solubility	Aqueous Base (Slightly), Water (Very Slightly)
form	Solid
pka	0.47±0.25(Predicted)
color	Pale Beige to Light Brown
Merck	13,8071
Stability:	Hygroscopic

Safety information for 4-Pyridoxic acid

Signal word	Warning
Pictogram(s)	Exclamation Mark Irritant GHS07
GHS Hazard Statements	H315:Skin corrosion/irritation H319:Serious eye damage/eye irritation H335:Specific target organ toxicity, single exposure;Respiratory tract irritation
Precautionary Statement Codes	P261:Avoid breathing dust/fume/gas/mist/vapours/spray. P264:Wash hands thoroughly after handling. P264:Wash skin thouroughly after handling. P271:Use only outdoors or in a well-ventilated area. P280:Wear protective gloves/protective clothing/eye protection/face protection. P302+P352:IF ON SKIN: wash with plenty of soap and water. P305+P351+P338:IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.