摘要:
Prostate specific membrane antigen (PSMA) is a validated molecular marker for prostate cancer. A series of glutamate-urea (Glu-urea-X) heterodimeric inhibitors of PSMA were designed and synthesized where X = epsilon-N-(o-I, m-I, p-I, p-Br, o-C1, m-C1, p-C1, p-F, H)-benzyl-Lys and epsilon-(p-I, p-Br, p-C1, p-F, H)-phenylureido-Lys. The affinities for PSMA were determined by screening in a competitive binding assay. PSMA binding of the benzyllysine series was significantly affected by the nature of the halogen substituent (IC50 values, Cl < I = Br << F = H) and the ring position of the halogen atom (IC50 values, p-I < o-I << m-I). The halogen atom had little affect oil the binding affinity in the para substituted phenylureido-Lys series. Two lead iodine compounds were radiolabeled with I-123 and I-131 and demonstrated specific PSMA binding on human prostate cancer cells, warranting evaluation as radioligands for the detection, staging, and monitoring of prostate cancer.