Cat. No.: HY-100806

Kynurenic acid

(Synonyms: Quinurenic acid)

11 Cited Publications

Customer Review

Based on 11 publication(s) in Google Scholar

Kynurenic acid, an endogenous tryptophan metabolite, is a broad-spectrum antagonist targeting NMDA, glutamate, α7 nicotinic acetylcholine receptor. Kynurenic acid is also an agonist of GPR35/CXCR8.

For research use only. We do not sell to patients.

Purity: 99.93%
CAS No.: 492-27-3
Formula: C₁₀H₇NO₃
Molecular Weight:189.17

Storage:

Powder -20°C, 3 years , 4°C, 2 years ; In solvent -80°C, 2 years , -20°C, 1 year

Kynurenic acid Chemical Structure

CAS No.: 492-27-3

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Top Publications Citing

Use of MCE Products

Fluorescent Dye

Strong Fluorescence Signal / Multi-Disciplinary Applications / High Fluorescence Specificity

Biological Activity
- Description
- IC₅₀ & Target
- Cellular Effect
- In Vitro
- In Vivo
- Clinical Trial
Chemical Information
Publications (11)
Solvent & Solubility
- In Vitro
- In Vivo
Protocol
Purity & Documentation
References
Help & FAQs
Bioz

Biological Activity

Description

IC₅₀ & Target^[1]

Human Endogenous Metabolite

NMDA Receptor

GPR35

All iGluR Isoforms :

All Endogenous Metabolite Isoforms :

All CXCR Isoforms :

Cellular Effect

Cell Line	Type	Value	Description	References
CHO	EC₅₀	217 μM Compound: 1	Agonist activity at human GPR35 expressed in CHO cells assessed as induction of beta-arrestin recruitment after 90 mins by beta-galactosidase reporter gene assay Agonist activity at human GPR35 expressed in CHO cells assessed as induction of beta-arrestin recruitment after 90 mins by beta-galactosidase reporter gene assay	[PMID: 23713606]
CHO	EC₅₀	39.2 μM Compound: 1	Agonist activity at human GPR35 expressed in CHO cells assessed as increase in intracellular Ca2+ measured over 20 secs by Aequorin assay Agonist activity at human GPR35 expressed in CHO cells assessed as increase in intracellular Ca2+ measured over 20 secs by Aequorin assay	[PMID: 23888932]
CHO	EC₅₀	66 μM Compound: 1	Agonist activity at rat GPR35 expressed in CHO cells assessed as induction of beta-arrestin recruitment after 90 mins by beta-galactosidase reporter gene assay Agonist activity at rat GPR35 expressed in CHO cells assessed as induction of beta-arrestin recruitment after 90 mins by beta-galactosidase reporter gene assay	[PMID: 23713606]
HT-29	EC₅₀	152 μM Compound: Kynurenic acid	Agonist activity at GPR35 in human HT-29 cells by dynamic mass redistribution assay Agonist activity at GPR35 in human HT-29 cells by dynamic mass redistribution assay	[PMID: 22572579]
U2OS	EC₅₀	>500 μM Compound: Kynurenic acid	Agonist activity at GPR35 in human U20S cells expressing beta-lactamase and Gal4-VP16 transcription factor assessed as beta arrestin translocation after 5 hrs by Tango assay Agonist activity at GPR35 in human U20S cells expressing beta-lactamase and Gal4-VP16 transcription factor assessed as beta arrestin translocation after 5 hrs by Tango assay	[PMID: 22572579]

In Vitro

GPR35 functions as a receptor for the kynurenine pathway intermediate kynurenic acid. Kynurenic acid elicits calcium mobilization and inositol phosphate production in a GPR35-dependent manner in the presence of G _qi/o chimeric G proteins. Kynurenic acid stimulates [³⁵S]guanosine 5′-O-(3-thiotriphosphate) binding in GPR35-expressing cells, an effect abolished by pertussis toxin treatment. Kynurenic acid also induces the internalization of GPR35^[1]. KYNA’s neuroinhibitory qualities and its neuroprotective and anticonvulsant effects are discovered using concentrations of the compound in the millimolar range. This, as well as the low affinity of KYNA at each of the three ionotropic glutamate receptors responsible for these effects [NMDA, alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) and kainate], together with the realization that KYNA concentrations in the mammalian brain are in the sub-micromolar range, suggested that other receptors might serve as targets of endogenous Kynurenic acid. Kynurenic acid, with a shallower inhibition curve and non-competitively, antagonizes α7nAChRs on cultured hippocampal neurons with an IC₅₀ in the low micromolar range^[2].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

In Vivo

Kynurenic acid affects the activity of leukocytes in the peripheral blood of mice, although the lowest one (2.5 mg/L) has the most profound influence in contrast to the highest one (250 mg/L), which produces the weakest effect. The lowest Kynurenic acid dose stimulates the proliferative response of T lymphocytes (p<0.05), after 7 and 28 days of administering the acid to the animals^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Clinical Trial

NCT Number	Sponsor	Condition	Start Date	Phase A549
NCT01329991	Plexxikon\|		2011-05	PHASE1

Chemical Information

CAS No. 492-27-3
Appearance Solid
Molecular Weight 189.17
Formula C₁₀H₇NO₃
Color Off-white to light yellow
SMILES

O=C(C1=NC2=CC=CC=C2C(O)=C1)O
Synonyms

Quinurenic acid
Structure Classification
- Alkaloids
- Quinoline Alkaloids
Initial Source
- Endogenous metabolite
- Human Gut Microbiota Metabolites
Shipping

Room temperature in continental US; may vary elsewhere.

Storage

Powder	-20°C	3 years
	4°C	2 years
In solvent	-80°C	2 years
	-20°C	1 year

Publications (11)

All Flow CytometryIn Vivo Efficacy StudyHistological Imaging/StainingBio/Physico-chemical Assay

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Journal Impact Factor

Immunity

Spatiotemporal dynamics of CXCL10 encode contextual immune information revealed by the genetically encoded fluorescent sensor. [Abstract]

2025 Sep 9;58(9):2320-2335.e9. PMID: 40818452
Nat Metab

Total parenteral nutrition impairs glucose metabolism by modifying the gut microbiome. [Abstract]

2023 Feb;5(2):331-348. PMID: 36782071

Kynurenic acid purchased from MedChemExpress. Usage Cited in: Nat Metab. 2023 Feb;5(2):331-348. [Abstract]

The correlation heat map revealed that TPN-induced depletion of Lactobacillaceae and Muribaculum was positively correlated with the levels of IAA, ILA, indole and Kynurenic acid, while TPN-induced enrichment of Akkermansia, Helicobacter and Oscilibacter was negatively associated with indole metabolites.

Kynurenic acid purchased from MedChemExpress. Usage Cited in: Nat Metab. 2023 Feb;5(2):331-348. [Abstract]

After administration of Kynurenic acid to a TPN mouse model, the blood concentration of kynurenic acid at the samples harvest time point.
Neuron

Dual anterior insula-prefrontal cortex circuits mediate chronic stress-induced social interaction deficits. [Abstract]

2026 Mar 26:S0896-6273(26)00120-0. PMID: 41895265
Mol Metab

The central amygdala gates exogenous glucagon-like peptide 1 signals. [Abstract]

2026 Jun 18:110:102403. PMID: 42314903
Antioxidants (Basel)

Kynurenic Acid/GPR35 Signaling Protects the Infarcted Heart by Suppressing Macrophage mtDNA-Triggered cGAS-STING Activation. [Abstract]

2026 Feb 27;15(3):300. PMID: 41897447
J Anim Sci Biotechnol

Regulation of serotonin production by specific microbes from piglet gut. [Abstract]

2023 Aug 5;14(1):111. PMID: 37542282
Cell Prolif

Tryptophan Metabolic Enzyme IL4I1 Inhibits Ferroptosis by Decreasing Ubiquitination of Nrf2 via I3P in Glioblastoma. [Abstract]

2025 Jun;58(6):e13816. PMID: 40071723
Int Immunopharmacol

The tryptophan metabolite kynurenic acid ameliorates septic colonic injury through activation of the PPARγ signaling pathway. [Abstract]

2024 Dec 31:147:113651. PMID: 39742725

Kynurenic acid purchased from MedChemExpress. Usage Cited in: Int Immunopharmacol. 2024 Dec 31:147:113651. [Abstract]

Following KYNA (100 μM, 4 h) treatment, the expression level of CD206 in M1 macrophages was significantly upregulated, indicating that KYNA can indeed promote the transformation of M1 macrophages into M2 macrophages.

Kynurenic acid purchased from MedChemExpress. Usage Cited in: Int Immunopharmacol. 2024 Dec 31:147:113651. [Abstract]

A comparison of the colon lengths among the five groups revealed that KYNA (1.5-2.5 mg/kg) intervention slightly improved the colon lengths of the mice.

Kynurenic acid purchased from MedChemExpress. Usage Cited in: Int Immunopharmacol. 2024 Dec 31:147:113651. [Abstract]

The presence of KYNA (0.5-2.5 mg/kg) led to a reduction in colon damage, restoration of mucosal integrity, and its protective effect increased with higher dosages.
Sci Hortic

2025 Dec 11;355:114551.
In Vitro Cell Dev Biol Anim

Kynurenic acid promotes osteogenesis via the Wnt/β-catenin signaling. [Abstract]

2023 May;59(5):356-365. PMID: 37291335
Res Sq

2025 Apr 08.

Solvent & Solubility

In Vitro:

0.1 M NaOH : 12.5 mg/mL (66.08 mM; ultrasonic and adjust pH to 9 with NaOH)

DMSO : 8.75 mg/mL (46.25 mM; Need ultrasonic; Hygroscopic DMSO has a significant impact on the solubility of product, please use newly opened DMSO)

H₂O : < 0.1 mg/mL (insoluble)

View the Complete Stock Solution Preparation Table

Preparing Stock Solutions

View the Complete Stock Solution Preparation Table

Concentration Solvent Mass

1 mg

5 mg

10 mg

Concentration

Solvent

Mass

1 mM

5.2863 mL

26.4313 mL

52.8625 mL

5 mM

1.0573 mL

5.2863 mL

10.5725 mL

10 mM

0.5286 mL

2.6431 mL

5.2863 mL

Please refer to the solubility information to select the appropriate solvent. Once prepared, please aliquot and store the solution to prevent product inactivation from repeated freeze-thaw cycles.

Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Molarity Calculator

Mass (g) = Concentration (mol/L) × Volume (L) × Molecular Weight (g/mol)

Mass Mass

Concentration Concentration

Volume Volume

Molecular Weight Molecular Weight

Dilution Calculator

Concentration _(start) × Volume _(start) = Concentration _(final) × Volume _(final)

Concentration _(start) Concentration _(start)

Volume _(start) Volume _(start)

Concentration _(final) Concentration _(final)

Volume _(final) Volume _(final)

In Vivo:

Select the appropriate dissolution method based on your experimental animal and administration route.

Stock Solution Working Solution

For the following dissolution methods, please ensure to first prepare a clear stock solution using an In Vitro approach and then sequentially add co-solvents:
To ensure reliable experimental results, the clarified stock solution can be appropriately stored based on storage conditions. As for the working solution for In Vivo experiments, it is recommended to prepare freshly and use it on the same day.
The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 10% DMSO 40% PEG300 5% Tween-80 45% Saline

Solubility: ≥ 1.25 mg/mL (6.61 mM); Clear solution

This protocol yields a clear solution of ≥ 1.25 mg/mL (saturation unknown).

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (12.5 mg/mL) to 400 μL PEG300, and mix evenly; then add 50 μL Tween-80 and mix evenly; then add 450 μL Saline to adjust the volume to 1 mL.

Protocol 2

Add each solvent one by one: 10% DMSO 90% Corn Oil

Solubility: ≥ 1.25 mg/mL (6.61 mM); Clear solution

This protocol yields a clear solution of ≥ 1.25 mg/mL (saturation unknown). If the continuous dosing period exceeds half a month, please choose this protocol carefully.

Taking 1 mL working solution as an example, add 100 μL DMSO stock solution (12.5 mg/mL) to 900 μL Corn oil, and mix evenly.

Working Solution

For the following dissolution methods, please prepare the working solution directly:

It is recommended to prepare fresh solutions and use them promptly within a short period of time.

The percentages shown for the solvents indicate their volumetric ratio in the final prepared solution. If precipitation or phase separation occurs during preparation, heat and/or sonication can be used to aid dissolution.

Protocol 1

Add each solvent one by one: 50% PEG300 50% Saline

Solubility: 33.33 mg/mL (176.19 mM); Suspended solution; Need ultrasonic

In Vivo Dissolution Calculator

Please enter the basic information of animal experiments:

Dosage Dosage
mg/kg
Animal Weight (Per Animal) Animal Weight (Per Animal)
g
Dosing Volume (Per Animal) Dosing Volume (Per Animal)
μL
Number of Animals Number of Animals

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Recommended: Prepare an additional quantity of animals to account for potential losses during experiments.

Please enter your animal formula composition:

%
DMSO +

Recommended: Keep the proportion of DMSO in working solution below 2% if your animal is weak.
%
+
+
%
Tween-80 + +
%
Saline +

The co-solvents required include: DMSO, . All of co-solvents are available by MedChemExpress (MCE). , Tween 80. All of co-solvents are available by MedChemExpress (MCE).

Working solution concentration: 0.22 mg/mL

Protocol

Kinase Assay^[1]

CHO-GPR35 stable cells are pretreated with or without pertussis toxin (100 ng/mL) for 16 h before harvesting. Cells are resuspended and homogenized in 10 mM Tris-HCl (pH 7.4), 1 mM EDTA followed by centrifugation at 1000 ×g for 10 min at 4 °C to remove nuclei and cellular debris. Membrane fractions are collected by spinning the supernatant at 38,000 ×g for 30 min and resuspended in 20 mM HEPES (pH 7.5) and 5 mM MgCl₂. 25 μg of membranes is incubated at room temperature for 1 h in assay buffer (20 mM HEPES, 5 m MMgCl₂, 0.1% bovine serum albumin (pH 7.5)) containing 3 μM GDP and 0.1 nM[³⁵S]GTPγS in the absence or presence of kynurenic acid. Reactions are terminated by vacuum filtration through GF/B filters, and the retained radioactivities are quantified on liquid scintillation counter^[1].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Animal Administration^[3]

Mouse: The experiment is performed on 160 male BALB/c mice, aged 10-12 weeks, with body weight of 22-26 g. The animals are maintained on a 12-h light/dark cycle at controlled temperature (20 ±1°C) and supplied with rodent chow and water ad libitum throughout the experiment. Mice are divided randomLy into four equal groups: control group (0) not receiving the Kynurenic acid, and three experimental groups administered the Kynurenic acid solution in drinking water at concentrations of 2.5, 25 or 250 mg/L. After 3, 7, 14 and 28 consecutive days of administration of the Kynurenic acid solution, 10 individuals from each group are sacrificed. The animals are anesthetized by inhalation of Aerrane and their blood is collected by heart puncture. Blood collected from five individuals of each group is used for the MTT assay, and from the next five for the flow cytometry^[3].

MedChemExpress (MCE) has not independently confirmed the accuracy of these methods. They are for reference only.

Purity & Documentation

Select Batch:

Purity: 99.98%

Assay: 99.98%

ee.: 99.98%

Data Sheet (282 KB)
SDS (396 KB)
- English - EN (396 KB)
- Français - FR (396 KB)
- Deutsch - DE (396 KB)
- Norwegian - NO (396 KB)
- Español - ES (396 KB)
- Swedish - SV (396 KB)
- Italian - IT (396 KB)
- Portuguese - PT (396 KB)
COA (2659 KB)
Elemental Analysis Report (2659 KB)
HNMR (2659 KB)
CNMR (2659 KB)
RP-HPLC (2659 KB)
NP-HPLC (2659 KB)
MS (2659 KB)
LCMS (2659 KB)
IR (2659 KB)
GC (2659 KB)
OR (2659 KB)
SDS-PAGE (2659 KB)
SEC-HPLC (2659 KB)
Other Report (2659 KB)
Handling Instructions (2659 KB)

References

[1]. Wang J, et al. Kynurenic acid as a ligand for orphan G protein-coupled receptor GPR35. J Biol Chem. 2006 Aug 4;281(31):22021-8. [Content Brief]

[2]. Albuquerque EX, et al. Kynurenic acid as an antagonist of α7 nicotinic acetylcholine receptors in the brain: facts and challenges. Biochem Pharmacol. 2013 Apr 15;85(8):1027-32. [Content Brief]

[3]. Małaczewska J, et al. Effect of oral administration of kynurenic acid on the activity of the peripheral blood leukocytes in mice. Cent Eur J Immunol. 2014;39(1):6-13. [Content Brief]

Help & FAQs

How should lyophilized recombinant proteins be reconstituted and stored?

1. Before opening the cap, centrifuge the vial at 13000 rpm for 20-30 seconds. This step will ensure that any lyophilized powder that may have adhered to the cap or walls is collected at the bottom of the vial, minimizing the risk of product loss.

Complete Stock Solution Preparation Table

Storage method and period of stock solution: -80°C, 2 years; -20°C, 1 year. When stored at -80°C, please use it within 2 years. When stored at -20°C, please use it within 1 year.

Optional Solvent	Concentration Solvent Mass	1 mg	5 mg	10 mg	25 mg
DMSO / 0.1 M NaOH	1 mM	5.2863 mL	26.4313 mL	52.8625 mL	132.1563 mL
	5 mM	1.0573 mL	5.2863 mL	10.5725 mL	26.4313 mL
	10 mM	0.5286 mL	2.6431 mL	5.2863 mL	13.2156 mL
	15 mM	0.3524 mL	1.7621 mL	3.5242 mL	8.8104 mL
	20 mM	0.2643 mL	1.3216 mL	2.6431 mL	6.6078 mL
	25 mM	0.2115 mL	1.0573 mL	2.1145 mL	5.2863 mL
	30 mM	0.1762 mL	0.8810 mL	1.7621 mL	4.4052 mL
	40 mM	0.1322 mL	0.6608 mL	1.3216 mL	3.3039 mL
0.1 M NaOH	50 mM	0.1057 mL	0.5286 mL	1.0573 mL	2.6431 mL
0.1 M NaOH	60 mM	0.0881 mL	0.4405 mL	0.8810 mL	2.2026 mL

Keywords

Kynurenic acid

11 Cited Publications

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Kynurenic acid

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Publications Citing Use of MedChemExpress (MCE) Kynurenic acid

All iGluR Isoforms

All Endogenous Metabolite Isoforms

All CXCR Isoforms

Biological Activity

Chemical Information

Publications (11)

Solvent & Solubility

Protocol

Purity & Documentation

References

Help & FAQs

Complete Stock Solution Preparation Table

Kynurenic acid Related Classifications

Cat. No.: HY-100806