66-72-8

Basic information

• Product Name: pyridoxal
• Synonyms: pyridoxal;PYRIDOXALDEHYDE;PYRIDOXALE;2-Methyl-3-hydroxy-5-(hydroxymethyl)pyridine-4-carbaldehyde;3-(Hydroxymethyl)-5-hydroxy-6-methylpyridine-4-carbaldehyde;3-Hydroxy-5-(hydroxymethyl)-2-methyl-4-pyridinecarbaldehyde;3-Hydroxy-5-hydroxymethyl-2-methylpyridine-4-carbaldehyde;3-hydroxy-2-methyl-5-methylol-isonicotinaldehyde
• CAS NO: 66-72-8
• Molecular Formula: C₈H₉NO₃
• Molecular Weight: 167.16196
• EINECS: 200-630-8
• Mol File: 66-72-8.mol
• Article Data: 24

Chemical Properties

• Melting Point: 165 °C
• Boiling Point: 412.8 °C at 760 mmHg
• Flash Point: 203.5 °C
• Appearance: /
• Density: 1.36 g/cm³
• Vapor Pressure: 1.48E-07mmHg at 25°C
• Refractive Index: 1.639
• Storage Temp.: under inert gas (nitrogen or Argon) at 2-8°C
• PKA: pKa 4.20 (H2O t = 25 I = 0.1)(Approximate)
• CAS DataBase Reference: pyridoxal(CAS DataBase Reference)
• NIST Chemistry Reference: pyridoxal(66-72-8)
• EPA Substance Registry System: pyridoxal(66-72-8)

Safety Data

• Hazardous Substances Data: 66-72-8(Hazardous Substances Data)

Usage

Definition

ChEBI: A pyridinecarbaldehyde that is pyridine-5-carbaldehyde bearing methyl, hydroxy and hydroxymethyl substituents at positions 2, 3 and 4 respectively.

Enzyme inhibitor

This photosensitive aldehyde form of vitamin B6 (FW = 167.16 g/mol), systematically referred to as 3-hydroxy-5-(hydroxymethyl)-2-methyl-4- pyridinecarboxaldehyde, is the immediate precursor to the coenzyme pyridoxal 5’-phosphate (PLP) and is often a weaker competitive inhibitor of PLP binding to PLP-dependent enzymes). Pyridoxal is soluble in water (1 g/2 mL) and sensitive to heat, particularly at alkaline pH. The pKa values are 4.23 (phenol OH), 8.70 (pyridinium NH+), and 13.0. Pyridoxal has a lmax value of 252 nm at pH 7.0 (e = 8200 M–1cm–1). It is typically supplied as the hydrochloride. Target(s): O-acetylhomoserine aminocarboxypropyltransferase, or O-acetylhomoserine (thiol)-lyase; alanine racemase; aldehyde dehydrogenase; arginine decarboxylase; cystathionine b-lyase, or cystine lyase; cysteine synthase; dextransucrase; b-fructofuranosidase, or invertase; glutamate dehydrogenase; hemoglobin S polymerization; hydroxyacyl-glutathione hydrolase, or glyoxalase II; kynurenine 3- monooxygenase; lactoylglutathione lyase, or glyoxalase I; NMN nucleosidase; phosphopantothenoylcysteine decarboxylase; porphobilinogen synthase, or d-aminolevulinate dehydratase; pyridoxal kinase; pyridoxal phosphatase, weakly inhibited; starch phosphorylase; thiamin phosphatase; tyrosinase; and xanthine dehydrogenase.

InChI:InChI=1/C8H9NO3/c1-5-8(12)7(4-11)6(3-10)2-9-5/h2,4,10,12H,3H2,1H3

Upstream product

• 85-87-0 pyridoxamine 
• 298-12-4 Glyoxilic acid 
• 328-50-7 α-ketoglutaric acid 
• 7732-18-5 water 
• 57-48-7 D-Fructose 
• 61-90-5 L-leucine 
• 2280-44-6 D-Glucose 
• 57-50-1 Sucrose 
• 58-86-6 D-xylose 
• 3458-28-4 D-Mannose 
• 10323-20-3 D-Arabinose 
• 50-69-1 D-ribose 
• 1114-34-7 D-lyxose 
• 2595-98-4 D-talose 

Downstream Products

• 122908-64-9 Schiff base pyridoxal-pyridoxamine 
• 7355-37-5 4-(hexylimino-methyl)-5-hydroxymethyl-2-methyl-pyridin-3-ol 
• 116324-89-1 4-Methoxy-benzoic acid [1-(3-hydroxy-5-hydroxymethyl-2-methyl-pyridin-4-yl)-meth-(E)-ylidene]-hydrazide 
• 4943-90-2 4-(p-ethoxyphenyliminomethyl)-5-hydroxy-6-methylpyridine-3-methanol 
• 25765-10-0 4-{[1-(3-Hydroxy-5-hydroxymethyl-2-methyl-pyridin-4-yl)-meth-(E)-ylidene]-amino}-benzoic acid 
• 72343-06-7 (E)-N'-((3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)methylene)benzohydrazide 
• 743386-82-5 2-{[1-(3-Hydroxy-5-hydroxymethyl-2-methyl-pyridin-4-yl)-meth-(E)-ylidene]-amino}-benzoic acid 
• 116324-90-4 4-Chloro-benzoic acid [1-(3-hydroxy-5-hydroxymethyl-2-methyl-pyridin-4-yl)-meth-(E)-ylidene]-hydrazide 
• 116324-86-8 4-Nitro-benzoic acid [1-(3-hydroxy-5-hydroxymethyl-2-methyl-pyridin-4-yl)-meth-(E)-ylidene]-hydrazide 
• 64896-38-4 3-Chloro-2-{[1-(3-hydroxy-5-hydroxymethyl-2-methyl-pyridin-4-yl)-meth-(E)-ylidene]-amino}-propionic acid 
• 116324-85-7 pyridoxal p-toluoylhydrazone 
• 19973-37-6 Pyridoxylidenbenzylamin 
• 19973-28-5 5-hydroxymethyl-2-methyl-4-(m-tolylimino-methyl)-pyridin-3-ol 
• 56583-59-6 7-hydroxy-1-methoxy-6-methyl-1H,3H-furo<3,4-c>pyridine 

Relevant articles and documents

Kinetics of Oxidation of Pyridoxine by Chloramine-T in Acid Medium

The kinetics of oxidation of pyridoxine (PRX) by chloramine-T (CAT) in the presence of hydrochloric acid (0.04-1.14 M) have been studied over teh temperature range of 303-323 K.The rate of the reaction shows first-order dependence on each of CAT, PRX, and chloride ion concentrations.The reaction rate is independent of hydrogen ion concentration.Variations of ionic strength and dielectric constant of the medium have negligible effect on the rate.Addition of the reaction product, p-toluenesulfonamide, decreases the rate showing a negative first order dependence.The solvent isotope effect has been studied by using heavy water.The activation parameters, Ea, ΔH, and ΔS are computed from the reaction rates at various temperatures.The mechanism of PRX oxidation proposed and the rate law derived are consistent with the observed kinetics.

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Purification, molecular cloning, and characterization of pyridoxine 4-oxidase from Microbacterium luteolum.

Pyridoxine 4-oxidase (EC 1.1.3.12, PN 4-oxidase), which catalyzes the oxidation of PN by oxygen or other hydrogen acceptors to form pyridoxal and hydrogen peroxide or reduced forms of the acceptors, respectively, was purified for the first time to homogeneity from Microbacterium luteolum YK-1 (=Aureobacterium luteolum YK-1). The purified enzyme required FAD for its catalytic activity and stability. The enzyme was a monomeric protein with the subunit molecular mass of 53,000 +/- 1,000 Da. PN was the only substrate as the hydrogen donor. Oxygen, 2,6-dichloroindophenol, and vitamin K3 were good substrates as the hydrogen acceptor. The gene (pno) encoding PN 4-oxidase was cloned. The gene encodes a protein of 507 amino acid residues corresponding to the molecular mass of the subunit. PN 4-oxidase was expressed in Escherichia coli and found to have the same properties as the native enzyme from M. luteolum YK-1. Comparisons of primary and secondary structures with other proteins showed that the enzyme belongs to the GMC oxidoreductase family. M. luteolum YK-1 has four plasmids. The pno gene was found on a chromosomal DNA. Search for genes similar in sequence in other organisms suggested that a nitrogen-fixing symbiotic bacterium, Mesorhizobium loti, which harbors two plasmids, has a PN degradation pathway I in chromosomal DNA.

Biochemical characterization of a recombinant acid phosphatase from Acinetobacter baumannii

Genomic sequence analysis of Acinetobacter baumannii revealed the presence of a putative Acid Phosphatase (AcpA; EC 3.1.3.2). A plasmid construct was made, and recombinant protein (rAcpA) was expressed in E. coli. PAGE analysis (carried out under denaturing/ reducing conditions) of nickel-affinity purified protein revealed the presence of a nearhomogeneous band of approximately 37 kDa. The identity of the 37 kDa species was verified as rAcpA by proteomic analysis with a molecular mass of 34.6 kDa from the deduced sequence. The dependence of substrate hydrolysis on pH was broad with an optimum observed at 6.0. Kinetic analysis revealed relatively high affinity for PNPP (Km = 90 μM) with Vmax, kcat, and Kcat/Km values of 19.2 pmoles s-1, 4.80 s-1(calculated on the basis of 37 kDa), and 5.30 × 104 M-1s-1, respectively. Sensitivity to a variety of reagents, i.e., detergents, reducing, and chelating agents as well as classic acid phosphatase inhibitors was examined in addition to assessment of hydrolysis of a number of phosphorylated compounds. Removal of phosphate from different phosphorylated compounds is supportive of broad, i.e., 'nonspecific' substrate specificity; although, the enzyme appears to prefer phosphotyrosine and/or peptides containing phosphotyrosine in comparison to serine and threonine. Examination of the primary sequence indicated the absence of signature sequences characteristic of Type A, B, and C nonspecific bacterial acid phosphatases.

Biomimic oxidation of pyridoxine by peroxo complex: A kinetic and mechanistic study

Bis-(ethylene diamine),bis-(diethylene triamine)peroxo dicobalt(III) perchlorate complex is synthesized by solution route. The prepared m-peroxo complex is characterized by FT-IR and electronic spectroscopy. The biomimic kinetics oxidations of pyridoxine by peroxo complex have been studied in aqueous medium. The reaction is first order each in the concentration of peroxo complex and H+ concentration. Increase in ionic strength has no effect on the reaction rate. The reaction does not induce the polymerization of acryl amide. The main products of the reaction has been isolated and identified by the spot test. The Arrhenius and the thermodynamic parameters have been calculated from the effect of temperature on the reaction rate. A suitable mechanism has been proposed and the experimental result is derived.