Effect of ruthenium complexation on trypanocidal activity of 5-nitrofuryl containing thiosemicarbazones

In the search of new therapeutic tools for the treatment of American Trypanosomiasis, the largest parasitic disease burden in the American continent, three series of novel ruthenium complexes of the formula [RuCl2(HL)(2)], [RuCl3(dmso)(HL)] and [RuCl(PPh3)(L)(2)] with bioactive 5-nitrofuryl containing thiosemicarbazones; as ligands (HL neutral, L monoanionic) were synthesized and characterized. Their in vitro growth inhibition activity against Trypanosoma cruzi and the effect of co-ligands in related physicochemical properties i.e. nitro moiety redox potential, lipophilicity and free radical scavenger capacity were evaluated. Results show that although a loss of activity was observed as a consequence of ruthenium complexation, lipophilicity and free radical scavenger capacity of the obtained complexes could be correlated to their trypanocidal effect. (C) 2009 Elsevier Masson SAS. All rights reserved.