Human Endogenous Metabolite
Pyridoxal targets various enzymes as a cofactor in the form of pyridoxal 5'-phosphate (PLP), the active coenzyme form of vitamin B6. PLP is involved in over 140 enzymatic reactions, including amino acid metabolism, neurotransmitter synthesis, and glycogenolysis. Pyridoxal serves as a precursor to PLP and is essential for normal physiological function.

In vitro, pyridoxal is used as a vitamin B6 supplement in cell culture media and as a reagent in enzymatic assays. It is a precursor to PLP, which is required for the activity of many enzymes. The compound is used to study vitamin B6 metabolism and the role of PLP-dependent enzymes in various biochemical pathways.

In vivo, pyridoxal is one of the natural forms of vitamin B6 and is used for nutritional supplementation. It is absorbed from the diet and converted to the active coenzyme PLP. Vitamin B6 is essential for normal brain development, immune function, and the maintenance of healthy levels of homocysteine. Pyridoxal is involved in what is believed to be the most ancient reaction of aerobic metabolism.

In vitro enzyme assays for pyridoxal typically measure the activity of PLP-dependent enzymes such as aminotransferases, decarboxylases, and racemases. The compound is converted to PLP by pyridoxal kinase, and the PLP is used as a cofactor for the enzyme reaction. The reaction products are quantified by spectrophotometric or chromatographic methods to assess enzyme activity and the effects of inhibitors or modulators.

In vitro cell experiments with pyridoxal involve supplementing cell culture media with the compound to study its effects on cellular metabolism and gene expression. Cells are cultured with varying concentrations of pyridoxal, and the activities of PLP-dependent enzymes, as well as markers of cellular function such as neurotransmitter levels or amino acid metabolism, are assessed.

In vivo animal experiments with pyridoxal are not extensively documented, as vitamin B6 is a well-established nutrient rather than a therapeutic drug. Studies on vitamin B6 deficiency in animal models may involve feeding animals a diet deficient in vitamin B6 and then supplementing with pyridoxal or other forms of vitamin B6 to assess the restoration of physiological functions.

Pyridoxal is absorbed from the gastrointestinal tract and converted to pyridoxal 5'-phosphate (PLP), the active coenzyme form of vitamin B6. PLP is involved in numerous enzymatic reactions and is essential for normal metabolism. The compound is water-soluble and is excreted in urine as metabolites. It is stable under normal storage conditions.

Pyridoxal is a form of vitamin B6, which is an essential nutrient with a well-established safety profile. Toxicity is rare but may occur at very high doses, causing sensory neuropathy. The compound is generally recognized as safe at recommended dietary levels. It is intended for nutritional supplementation and research use.

[1]. Hayashi H. Pyridoxal enzymes: mechanistic diversity and uniformity[J]. The journal of biochemistry, 1995, 118(3): 463-473.

Pyridoxal is a pyridinecarboxaldehyde, specifically pyridine-4-carboxaldehyde, with methyl, hydroxy, and hydroxymethyl substituents at positions 2, 3, and 5, respectively. It is the 4-carboxaldehyde form of vitamin B6 and can be converted to pyridoxal phosphate, which is a coenzyme for the synthesis of amino acids, neurotransmitters, sphingolipids, and aminolevulinic acid. Pyridoxal is metabolized in humans, Saccharomyces cerevisiae, Escherichia coli, and mice, where it functions as a cofactor. It is a vitamin B6, pyridinecarboxaldehyde, a methylpyridine compound, a monohydroxypyridine compound, and a hydroxymethylpyridine compound. It is the conjugate base of pyridoxal (1+). Pyridoxal is a metabolite found in or produced by Escherichia coli (K12 strain, MG1655 strain). Pyridoxal has also been reported in water fleas, soybeans, and other organisms with relevant data. Pyridoxal is a metabolite found in or produced by Saccharomyces cerevisiae. It is the 4-carboxyaldehyde form of vitamin B6, which can be converted into pyridoxal phosphate, a coenzyme for the synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, and aminolevulinic acid.

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Pharmacological Indications
Pyridoxal is one of the natural forms of vitamin B6 and can therefore be used for nutritional supplementation and treatment of dietary deficiencies and imbalances.

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Mechanism of Action
Pyridoxal is a precursor to pyridoxal phosphate. Pyridoxal 5'-phosphate participates in a variety of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemoglobin, sphingolipids and other sphingolipids, and the synthesis of neurotransmitters serotonin, dopamine, norepinephrine, and γ-aminobutyric acid (GABA).

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Pharmacodynamics
Pyridoxal mainly exists as coenzyme pyridoxal 5'-phosphate, participating in a variety of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemoglobin, sphingomyelin and other sphingolipids, as well as the synthesis of neurotransmitters serotonin, dopamine, norepinephrine and γ-aminobutyric acid (GABA).

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Pyridoxal is a form of vitamin B6 used for nutritional supplementation and the treatment of vitamin B6 deficiency. It is available as a dietary supplement and is involved in numerous metabolic processes as a precursor to the coenzyme PLP. No specific clinical trials for pyridoxal as a drug exist, as it is a well-known nutrient. Its mechanism of action involves conversion to PLP, which serves as a cofactor for over 140 enzymatic reactions.

C8H9NO3

167.16

167.058

66-72-8

Pyridoxal-d3 hydrochloride;1173023-49-8;Pyridoxal-d3;1173148-04-3

1050

White to off-white solid powder

1.36 g/cm3

412.8ºC at 760 mmHg

165 °C

1.639

0.4

2

4

2

12

162

0

CC1=NC=C(C(=C1O)C=O)CO

RADKZDMFGJYCBB-UHFFFAOYSA-N

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

3-hydroxy-5-(hydroxymethyl)-2-methylpyridine-4-carbaldehyde

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)