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mGluR5 Antagonist, MTEP - CAS 329205-68-7 - Calbiochem

The mGluR5 Antagonist, MTEP, also referenced under CAS 329205-68-7, controls the biological activity of mGluR5. This small molecule/inhibitor is primarily used for Neuroscience applications.

3-((2-Methyl-1,3-thiazol-4-yl)ethynyl)pyridine, mGluR5 Antagonist, MTEP - CAS 329205-68-7 - Calbiochem
Empirical Formula (Hill Notation):
CAS Number:
Molecular Weight:

Quality Level


≥98% (HPLC)





storage condition

OK to freeze
protect from light


white to yellow


methanol: 1 mg/mL
DMSO: 5 mg/mL

shipped in


storage temp.


General description

A brain-permeable (thiazole-pyridine)alkyne compound that acts as a potent, selective and non-competitive mGluR5 (metabotropic glutamate receptor subtype-5) antagonist (IC50 = 5 nM in Ca2+-flux assay; Ki = 16 nM) with in vivo anxiolytic activity in a rodent model (ED50 = 1 mg/kg, ip and 7 mg/kg, po). Devoid of any side effects seen with MPEP and benzodiazepines. Reported to weakly affect the activities of other enzymes and receptors tested (IC50 = 30 µM for MAO-A, >100 µM for mGlu1R, 2R & 7R, and >300 µM for NR2BR).


5 mg in Plastic ampoule
Packaged under inert gas

Biochem/physiol Actions

Cell permeable: yes
Target Ki: 16 nM for mGluR5 (metabotropic glutamate receptor subtype-5)
Target IC50: 5 nM in Ca2+-flux assay
Product does not compete with ATP.
Reversible: no
Primary Target


Toxicity: Standard Handling (A)


Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 6 months at -20°C.

Other Notes

Bradbury, M.J., et al. 2005. J. Pharmacol. Exp. Ther.313, 395.
Busse, C.S., et al. 2004. Neuropsychopharmacology29, 1971.
Roppe, J.R., et al. 2004. Bioorg. Med. Chem. Lett.14, 3993.
Klodzinska, A., et al. 2004. Neuropharmacology47, 342.
Cosford, N.D.P., et al. 2003. J. Med. Chem.46, 204.
Brodkin, J., et al. 2002. Eur. J. Neurosci.16, 2241.

Legal Information

CALBIOCHEM is a registered trademark of Merck KGaA, Darmstadt, Germany

Storage Class Code

11 - Combustible Solids



Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Certificate of Origin

J Brodkin et al.
The European journal of neuroscience, 16(11), 2241-2244 (2002-12-11)
It hs been suggested that metabotropic glutamate receptor subtype 5 (mGluR5) play a role in the expression of anxiety, based on anxiolytic-like effects of the selective mGluR5 antagonist MPEP (2-methyl-6-(phenylethynyl)pyridine) in rodent models of anxiety, including stress-induced hyperthermia (SIH). To...
Nicholas D P Cosford et al.
Journal of medicinal chemistry, 46(2), 204-206 (2003-01-10)
2-Methyl-6-(phenylethynyl)pyridine (3), a potent noncompetitive mGlu5 receptor antagonist widely used to characterize the pharmacology of mGlu5 receptors, suffers from a number of shortcomings as a therapeutic agent, including off-target activity and poor aqueous solubility. Seeking to improve the properties of...
Aleksandra Klodzinska et al.
Neuropharmacology, 47(3), 342-350 (2004-07-28)
Several lines of evidence suggest a crucial involvement of glutamate in the mechanism of action of anxiolytic drugs including the involvement of group I metabotropic glutamate (mGlu) receptors. Given the recent discovery of a selective and brain penetrable mGlu5 receptor...
Jeffrey R Roppe et al.
Bioorganic & medicinal chemistry letters, 14(15), 3993-3996 (2004-07-01)
Structure-activity relationship studies leading to the discovery of a new, orally active mGlu5 receptor antagonist are described. The title compound, 5-[(2-methyl-1,3-thiazol-4-yl)ethynyl]-2,3'-bipyridine, is highly potent in vitro, has good in vivo receptor occupancy, and is efficacious in the rat fear-potentiated startle...
Chris S Busse et al.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology, 29(11), 1971-1979 (2004-08-12)
Previous reports have demonstrated the anxiolytic effect of the potent and systemically active metabotropic glutamate subtype 5 (mGlu5) receptor antagonist 2-methyl-6-(phenylethynyl)pyridine (MPEP) in rodents. Here, we present evidence for the anxiolytic activity of a novel mGlu5 receptor antagonist, 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP)...

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