Reactivity of [RuIII(pac)(H2O)] (pac = polyaminocarboxylate) complexes with 5′-nucleotides and their antitumor activity

The reaction of [RuIII(edta)(H2O)]− (edta4− = ethylenediaminetetraacetate) and [RuIII(hedtra)(H2O)] (hedtra3− = N-hydroxyethylethylenediaminetriacetate) with various purine based 5′-nucleotides (Nu) viz. adenosin-5′-monophosphate (AMP), guanosin-5′-monophosphate (GMP), inosin-5′-monophosphate (IMP) was studied kinetically as a function of [Nu] at various temperatures (15–35 °C) at a fixed pH (4.5). Kinetic results suggest that the binding of 5′-nucleotides takes place in a rapid [Nu] dependent rate-determining step. Kinetic data and activation parameters are accounted for the operation of an associative mechanism. The antitumor activities of both [RuIII(edta)(H2O)]− (1) and [RuIII(hedtra)(H2O] (2) have been evaluated using MCF-7 (breast cancer), NCI-H460 (lung cancer) and SF-268 (CNS) cell lines.