A potent inhibitor of GCP II/NAALADase (Ki = 98 pM for release of glutamate from the NAALADase peptide substrate NAAG); selective for GCP II/NAALADase over a panel of 100 receptors, transporters, ion channels, and enzymes at a concentration of 10 μM; neuroprotective against hypoxia (EC50 = 8.4 μM) in neuron-enriched primary cultures from rat embryo cerebellum; reduces neuronal cell death induced by middle cerebral artery occlusion in rats; blocks the conditioned place preference response to cocaine in male rats (100 mg/kg); reduces the number of flinches induced by formalin injection into the footpad of mice (10 μg per animal); decreases severity and delays onset of EAE in mice,