This invention provides new compounds, pharmaceutical compositions and diagnostic kits comprising such compounds, and methods of using such compounds for inhibiting NAALADase enzyme activity, detecting diseases where NAALADase levels are altered, inhibiting angiogenesis, effecting a TGF-.beta. activity or a neuronal activity, and treating a glutamate abnormality, a compulsive disorder, neuropathy, pain, a prostate disease, cancer, Huntington's disease, diabetes, a retinal disorder or glaucoma.