Many Pt compounds show antitumor properties against various solid tumors. Even the most widely used antitumor Pt drug, cisplatin, exhibits many adverse side effects. Certain PtIV - complex drugs exhibit less toxicity and function as prodrugs that are converted into more reactive PtII species intracellularly. The present application deals with the reduction chemistry of ptIV conversion to PtII species. It is hypothesized that the axial ligands of the PtIV complexes may play an important role in controlling the reduction chemistry of this conversion, thereby generating various analogs of PtII that exhibit a wide range of cytotoxicity. Dr. Choi proposes in this application to test the validity of this hypothesis by studying the kinetics and reaction chemistry of PtIV compounds by high performance liquid chromatography, UV/vis and 195Pt-NMR spectroscopy.