Kinetic and Mechanistic Studies on the Reaction of DL-Methionine with [(H2O)(tap)2RuORu(tap)2(H2O)]2+ in Aqueous Medium at Physiological pH

Introduction e binding of the antitumor drug cisplatin and other platinum group metal complexes, especially ruthenium(II), rhodium(III), iridium(III), platinum(II), and palladium(II) to amino acids, nucleosides, nucleotides, and particularly to DNA is still an interesting subject and has given considerable impetus to research in the area of metal ion interactions with nucleic acid constituents. Ruthenium complexes are an order of magnitude less toxic than cisplatin, and aqua complexes if used directly will be less toxic as some hydrolyzed side products are responsible for toxicity. From a literature survey [1-3], it is revealed that many potential alternative metallopharmaceuticals have been developed, ruthenium being one of the most promising, and are currently undergoing clinical trials [4-7]. Another point of interest is that DNA is not the only target. Binding to proteins, RNA [8-10] and several sulphur donor ligands, present in the blood, are available for kinetic and thermodynamic competition [11, 12].