Complexos de rutênio tipo [ruii(bd)(tpy)l](pf6)n (l = CI, H2O, NO+, NO2) e modelos de interação com o DNA

Abstract

Considering the epidemiological profile that cancer and all the problems it causes, several studies are developed and improved to synthesize drugs with antitumor potential. The first studies occurred in 1960 when they found the antitumor activity of cis- diamminedichloridoplatinum (II), more commonly called cisplatin. However, Pt (II) metallopharmaceuticals present cellular resistance and also several side effects, such as nausea, vomiting, and even neurotoxicity. In addition, it should be taken into account that tumor cells have their own characteristics and, consequently, tumors are unique, making the development of some efficient chemotherapy in view of all types of cancers impossible. Therefore, new and different coordination compounds are developed as potential drugs in antitumor action. Some compounds of coordination with ruthenium metal center (II) with polypyridine ligands have shown promise in the case of potential antitumor complexes, presenting activities in tumors that have developed resistance to cisplatin or, even, in which cisplatin is inactive. Thus, the synthesis and characterization of ruthenium complexes of type [RuCl(bd)(tpy)]PF6, [Ru(H2O)(bd)(tpy)](PF6)2, [Ru(bd)(tpy)(NO)](PF6)3 and [Ru(NO2)(bd)(tpy)]PF6 – in which tpy=2,2':6',2"-terpyridine; bd= o-phenylenediamine – and, subsequently, the evaluation of the interaction of these complexes with the DNA molecule extracted from salmon sperm. The studies were conducted using spectroscopic techniques in the Ultraviolet-Visible region, circular dichroism, and thermal denaturation of the DNA molecule and demonstrated weak to moderate interaction between the complexes and the biomolecule, with interaction constant (Kb) in the order of 10-4 M-1 for all cases. In this series of complexes under study, intercalating complexes and complexes that interact by electrostatic interaction were identified.