CHEMISTRY

Reaction of ruthenium(III) complexes with heterocyclic ligands and glutathione. BETHANY ALICIE*, AMANDA MOORE, and KEVIN M. WILLIAMS, Department of Chemistry, Western Kentucky University, Bowling Green, KY 42101-1079.

Selected ruthenium complexes have been shown to have anticancer activity, most likely due to interaction with DNA. Ruthenium complexes also are known to interact with proteins and react specifically with histidine residues. Such specificity is potentially useful since certain metal ion complexes catalyze amide bond hydrolysis in proteins and thus certain ruthenium complexes could show a selective cleavage at histidine residues. Because ruthenium(III) complexes are generally inert to substitution and ruthenium(II) complexes are generally not air-stable, previous studies have utilized a zinc-amalgam reduction step and a strict argon atmosphere. We are trying to develop conditions that permit the reaction between ruthenium(III) complexes and histidine targets without the use of mercury or the necessity of a glove box. We have found that a ruthenium(III) compound mixed with glutathione and a heterocyclic ligand in an argon-purged flask can react to form a complex between the ruthenium and the heterocyclic ligand, and previous studies suggest that glutathione reduces the ruthenium(III) as part of the mechanism [Frasca, D.R.; Clarke, M.J. J Am. Chem. Soc., 1999, 121, 8523-8532]. We are determining ideal conditions for the reaction of ruthenium with histidine using UV-Vis and NMR spectroscopy.