Metabotropic glutamate receptors (mGluR)

(-)-Huperzine A is a naturally occurring sesquiterpene alkaloid compound found in the firmoss Huperzia serrata.

Brophenexin (compound 8) is a potent inhibitor of the interaction interface between NMDA receptors (NMDAR) and TRPM4 channels, exhibiting significant neuroprotective activity. It prevents NMDA-induced excitotoxicity, including cell death and mitochondrial dysfunction in hippocampal neurons, with an IC₅₀ of 2.1 μM. In vivo, Brophenexin protects against brain damage in mice subjected to middle cerebral artery occlusion (MCAO) and preserves retinal ganglion cells from NMDA-induced degeneration. These findings support its potential as a therapeutic agent for neurodegenerative diseases and ischemic brain injury.

Evans Blue is a potent inhibitor of L-glutamate uptake through the membrane-bound excitatory amino acid transporter (EAAT). This compound effectively inhibits L-glutamate and kainate receptor-mediated currents, making it valuable for research into neurophysiological processes. Additionally, due to its strong affinity for serum albumin, Evans Blue serves as a high molecular weight protein tracer and is widely used to investigate blood-brain barrier (BBB) permeability.

MK-8768 is a potent and selective negative allosteric modulator of the metabotropic glutamate receptor 2 (mGluR2), exhibiting an IC50 value of 9.6 nM. This compound demonstrates excellent bioavailability and brain permeability, making it suitable for investigations into neurological disorders associated with glutamate signaling. It serves as a valuable tool for research applications aimed at understanding the modulation of mGluR2 in various physiological and pathological contexts.

PF470 is a negative allosteric modulator of metabotropic glutamate receptor 5 (mGluR5). It has demonstrated significant efficacy in preclinical models of Parkinson's disease, making it a valuable tool for investigating the role of mGluR5 in neurological disorders. Despite its potential, further clinical development was halted due to concerns identified in toxicology assessments.

Ro4491533 is a selective negative allosteric modulator of the mGluR2 and mGluR3 receptors. It effectively inhibits glutamate-induced calcium mobilization and decreases [35S]GTPγS binding, demonstrating its capacity to modulate glutamatergic signaling. This compound exhibits favorable pharmacokinetic properties, including high oral bioavailability and the ability to penetrate the blood-brain barrier. Additionally, Ro4491533 has shown potential in reversing motor inhibition caused by LY379268 and displays antidepressant effects in various behavioral tests such as the forced swim test and tail suspension test.