Synthesis of (diamine)platinum(II) and (diamine)platinum(IV) complexes of isopropylidenmalonate ligand and their interaction with guanosine-5′-monophosphate

A series of (diamine)isopropylidenmalonatoplatinum(II) complexes and the oxidation products, (diamine)Pt (OOC)(2)C=C(CH3)(2)(X)(2), (diamine-ethylenediamine(en), 1,2-diaminopropan(dap), N-methylethylenediamine(men); X=OH, OCOCH3, OCOCF3), have been prepared, and their interaction with guanosine-5'-monophosphate (5'-GMP) have been examined by means of H-1 NMR spectroscopy. The present platinum(II) complexes have shown to interact with 5'-GMP through N7 coordination in two concecutive steps in a similar way as with cisplatin, but no interaction between the present platinum(IV) complexes and 5'-GMP was observed. However, in the presence of ascorbic acid, the platinum(IV) complexes have been found to interact with 5'-GMP with the reaction rate depending on their reduction rate.