Palladium-based chemotherapeutic agents: Routes toward complexes with good antitumor activity

Chemical-, pharmacological-, and clinical-research on anticancer coordination complexes has yielded remarkable anticancer agents such as cisplatin, carboplatin, and oxaliplatin. Since the discovery of cisplatin, the development of analogue complexes has been an empirical task. Studies have shown that the range of platinum complexes with antitumor activity is not restricted to the structural analogues of cisplatin. The established structure-activity rules have been broken: active platinum complexes without NH groups, trans-platinum complexes, multinuclear complexes, cationic complexes, and several classes of palladium (II) complexes have emerged. The foremost target of most research groups was to find a convenient anticancer drug that can be used efficiently for the treatment of human tumors. This study gives an up to date overview of the anticancer chemistry of palladium compounds with an emphasis on the new strategies used in the development of new palladium antitumor agents.