Group I metabotropic glutamate receptor antagonist (IC50 ~ 3 μM); 67 times more potent than (S)-4-carboxyphenylglycine (Cat. No. 0323). Also a positive allosteric modulator for mGlu4a; potentiates L-AP4-mediated inhibition of striatopallidal synaptic transmission in vitro. Displays antiParkinsonian effects in rats in vivo.