LY 341495 has been shown to be a highly potent and selective group II metabotropic glutamate receptor (mGluR-2) antagonist with Ki / IC50 values are 2.3, 1.3, 173, 990, 6800, 8200 and 22000 nM for human mGluR-2, mGluR-3, mGluR-8 , mGluR-7a, mGluR-1a, mGluR-5a and mGluR-4a.
MPEP is a potent and highly selective non-competitive antagonist at the mGlu5 receptor subtype (IC50 = 36 nM) and a positive allosteric modulator at mGlu4 receptors.
DL-AP3, a racemic preparation of D-AP3 and L-AP3, is an inhibitor of phosphoserine phosphatase and an antagonist of the metabotropic glutamate receptor (mGluR), blocking phosphoinositide turnover mediated by the mGluR.
Fenobam is a selective, orally active, and non-competitive mGluR5 antagonist acting at an allosteric modulatory site (Kd values are 54 and 31 nM for rat and human recombinant mGlu5 receptors, respectively).
JNJ16259685 is a selective antagonist of mGlu1 receptor, and inhibits the synaptic activation of mGlu1 in a concentration-dependent manner with IC50 of 19 nM.