Síntese e caracterização de complexos tiadiazol-paládio (II) como potencial agente antineoplásico

Abstract

The research developed in the last decades involving the synthesis of coordination compounds with possible pharmacological applications is increasing. Compounds derived from Palladium have been gaining prominence, since it has shown great versatility both in synthesis and in application, since they have biological activity against various diseases, such as antineoplastic, leishmanicidal, fungicidal activity. This aroused the interest of many researchers, who began to consider this metal as the focus of their research. Therefore, this study aimed at the synthesis, characterization and evaluation of the antineoplastic activity of new palladium (II) mononuclear complexes containing compounds of the thiadiazole class as ligands. Complexes of the type [Pd(dmba)µ-X]2 where X= Cl, Br, I and N3 were reacted with the compound 2,5-dimethyl-1,3,4-thiadiazole (dtz) in situ, yielding compounds of the type [Pd(dmba)X(dtz)] where X=Cl, Br, I and N3. The synthesized complexes were characterized using vibrational spectroscopy in the infrared region, 1H and 13C Nuclear Magnetic Resonance (NMR) and thermogravimetric analysis (TG-DTG). The results pointed to the formation of a chelate compound, in which the palladium ion bonded to a nitrogen atom and a carbon atom of the dmba compound, forming a cyclometallic ring, it also bonds to a halide or pseudo-halide, and the dtz ligand coordinated to the palladium atom through a nitrogen atom present in its hetero ring. All synthesized complexes were submitted to biological assay, evaluating cell viability in cultures of HepG2, MCF-7, A549 and dermal fibroblasts; and the cell cycle in HepG2-like cells from cultures treated with the synthesized products. It was found that the synthesized complexes have a cell viability rate of 50% to 70%, the most promising being the compound [Pd(dmba)Br(dtz) in HepG2-type cells, in MCF-7-type cell culture the rate varies from 50% to 75%, with the HepG2 type being more sensitive when compared to MCF-7, type A549 culture proved to be resistant to the synthesized compounds