ZJ43 is a potent inhibitor of glutamate carboxypeptidase II (K(i) = 0.8 nM) and III (K(i) = 23 nM) that inhibits the hydrolysis of NAAG (IC50 = 2.4 nM). ZJ43 sufficiently activates group II mGluR and reduces some of the behavioral effects of PCP. ZJ43 shows an analgesic effect in neuropathic and inflammatory and pain models [1].