Synthesis and biological evaluation of aryl isoxazole derivatives as metabotropic glutamate receptor 1 antagonists: a potential treatment for neuropathic pain.

Glutamate is the major excitatory neurotransmitter and known to activate the metabotropic and ionotropic glutamate receptors in the brain. Among these glutamate receptors, metabotropic glutamate receptor 1 (mGluR1) has been implicated in various brain disorders including anxiety, schizophrenia and chronic pain. Several studies demonstrated that the blockade of mGluR1 signaling reduced pain responses in animal models, suggesting that mGluR1 is a promising target for the treatment of neuropathic pain. In this study, we have developed mGluR1 antagonists with an aryl isoxazole scaffold, and identify several compounds that are orally active in vivo. We believe that these compounds can serve as a useful tool for the investigation of the role of mGluR1 and a promising lead for the potential treatment of neuropathic pain.