3-Hydroxyflavones vs. 3-hydroxyquinolinones: structure–activity relationships and stability studies on Ru<sup>II</sup>(arene) anticancer complexes with biologically active ligands
作者:Andrea Kurzwernhart、Wolfgang Kandioller、Éva A. Enyedy、Maria Novak、Michael A. Jakupec、Bernhard K. Keppler、Christian G. Hartinger
DOI:10.1039/c2dt32206d
日期:——
RuII(η6-arene) complexes, especially with bioactive ligands, are considered to be very promising compounds for anticancer drug design. We have shown recently that RuII(η6-p-cymene) complexes with 3-hydroxyflavone ligands exhibit very high in vitro cytotoxic activities correlating with a strong inhibition of topoisomerase IIα. In order to expand our knowledge about the structureâactivity relationships and to determine the impact of lipophilicity of the arene ligand and of the hydrolysis rate on anticancer activity, a series of novel 3-hydroxyflavone derived RuII(η6-arene) complexes were synthesised. Furthermore, the impact of the heteroatom in the bioactive ligand backbone was studied by comparing the cytotoxic activity of RuII(η6-p-cymene) complexes of 3-hydroxyquinolinone ligands with that of their 3-hydroxyflavone analogues. To better understand the behaviour of these RuII complexes in aqueous solution, the stability constants and pKa values for complexes and the corresponding ligands were determined. Furthermore, the interaction with the DNA model 5â²-GMP and with a series of amino acids was studied in order to identify potential biological target structures.