Platinum(II) complexes of functionalized malonato ligands: unequivocal synthesis, interaction with a tetradeoxyribonucleotide and deoxyribonucleic acid

Abstract

The unequivocal syntheses of four cis-[PtL₂{(O₂C)₂CH(CH₂)_nCO₂H}] complexes [L₂=(NH₃)₂ or trans-cyclohexane-1,2-diamine, n= 1 or 4] has been achieved, avoiding any interaction between the pendant carboxyl group and the platinum. The complexes have been characterized by elemental analysis, ¹³C NMR and FAB mass spectroscopy. Their interaction with a tetradeoxyribonucleotide d(T-G-G-T)(G = guanosine, T = ribosylthymine) and DNA (in vitro) has been investigated to show that they form adducts of the type [PtL₂{(GpG)-N⁷,N^7′}] as do known therapeutically active platinum complexes. However the presence of the free carboxyl function increases significantly the reactivity with respect to that of the related non-functionalized malonato complexes [PtL₂{H₂C(CO₂)₂}].