Selective group III metabotropic glutamate receptor antagonist. Displays an apparent KD of 51 μM for the L-AP4-sensitive presynaptic mGluR on primary afferent terminals in spinal cord compared to > 700 μM for the (1S,3S)-ACPD-sensitive presynaptic mGlu in the same system. Has no activity on postsynaptic mGlu receptors or on ionotropic glutamate receptors on neonatal rat motoneurons. Also available as part of the Group III mGlu Receptor Tocriset?. MW (observed): 199.1.