Synthesis of platinum complexes with ligands of peripheral benzodiazepine receptors

Peripheral benzodiazepine receptors (PBR) are located on the outer membrane of mitochondria, and are a novel therapeutic target. The PBR expression is selectively increased in both experimental and human brain tumors compared to normal brain and peripheral tissues. In fact, PBR expression in the brain correlates with the degree of tumor malignancy. The identification of the PBRs in brain tumors has also served as a means to evaluate PBR ligands as diagnostic imaging agents. Therefore, these characteristics of PBRs in tumors suggest that PBR ligands can serve as receptor-mediated drug carriers to selectively target cancer cells. Substances with receptor affinity and that cant' cytotoxic groups were thought to be good candidates for this purpose. In this work the synthesis, isolation, purification and characterization using spectroscopic methods of various benzodiazepine-platinum complexes as potential cytotoxic agents is presented. The diaminodichloroplatinum(II) group was chosen as the cytotoxic function because the parent compound cis-platinum is a potent antineoplastic agent against some tumors.