Cinnabarinic acid is an mGlu4-specific allosteric agonist that can interact with the glutamate-binding pocket residues of mGlu4 and has no activity on other mGlu receptor subtypes. Cinnabarinic acid is an endogenously produced metabolite of the tryptophan kynurenine pathway. Cinnabarinic acid can cause apoptosis.

Physicochemical Properties

Molecular Formula	C14H8N2O6
Molecular Weight	300.22
Exact Mass	300.038
CAS #	606-59-7
PubChem CID	114918
Appearance	Brown to reddish brown solid powder
Density	1.8±0.1 g/cm3
Boiling Point	536.8±50.0 °C at 760 mmHg
Melting Point	>300ºC
Flash Point	278.4±30.1 °C
Vapour Pressure	0.0±1.5 mmHg at 25°C
Index of Refraction	1.780
LogP	-0.13
Hydrogen Bond Donor Count	3
Hydrogen Bond Acceptor Count	8
Rotatable Bond Count	2
Heavy Atom Count	22
Complexity	675
Defined Atom Stereocenter Count	0
InChi Key	FSBKJYLVDRVPTK-UHFFFAOYSA-N
InChi Code	InChI=1S/C14H8N2O6/c15-10-6(17)4-8-12(9(10)14(20)21)16-11-5(13(18)19)2-1-3-7(11)22-8/h1-4H,15H2,(H,18,19)(H,20,21)
Chemical Name	2-amino-3-oxophenoxazine-1,9-dicarboxylic acid
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	mGluR4
ln Vitro	Measurements of [3H]InsP production reveal that cinnabarinic acid (0-100 μM) does not activate mGlu1, mGlu2, mGlu5, mGlu6, mGlu7, and mGlu8 receptors. Cinnabarinic acid, on the other hand, functions as a partial agonist of mGlu4 receptors by raising [3H]InsP formation by about 35% at 100 μM. This means that it is five times less effective than ACPT-I at activating mGlu4 receptors in HEK293 cells transiently transfected with rat mGlu1, -2, -4, -5, -6, -7, or -8 receptors[1]. With remarkable potency and efficacy, cinnabarinic acid (0-100 μM) decreases the production of cAMP in a concentration-dependent manner. Cinnabarinic acid significantly reduces the synthesis of cAMP in cultured cerebellar granule cells at 30 μM, where it is effective[1].
References	[1]. Cinnabarinic acid, an endogenous metabolite of the kynurenine pathway, activates type 4 metabotropic glutamate receptors.Mol Pharmacol. 2012 May;81(5):643-56. [2]. The Trace Kynurenine, Cinnabarinic Acid, Displays Potent Antipsychotic-Like Activity in Mice and Its Levels Are Reduced in the Prefrontal Cortex of Individuals Affected by Schizophrenia. Schizophr Bull. 2020 Jun 7;sbaa074. [3]. Cinnabarinic acid and xanthurenic acid: Two kynurenine metabolites that interact with metabotropic glutamate receptors. Neuropharmacology. 2017 Jan;112(Pt B):365-372.
Additional Infomation	Cinnavalininate is a phenoxazine. Cinnavalininate is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).

Solubility Data

Solubility (In Vitro)

0.1 M NaOH : 10 mg/mL (33.31 mM) DMSO : 2.5 mg/mL (8.33 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 0.25 mg/mL (0.83 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 2.5 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: 0.25 mg/mL (0.83 mM) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), suspension solution; with ultrasonication. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 2.5 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.3309 mL	16.6545 mL	33.3089 mL
	5 mM	0.6662 mL	3.3309 mL	6.6618 mL
	10 mM	0.3331 mL	1.6654 mL	3.3309 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.