Banca de QUALIFICAÇÃO: DIANA TECIA DE LIMA SOUZA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : DIANA TECIA DE LIMA SOUZA
DATE: 13/07/2026
TIME: 14:00
LOCAL: Auditório do CCET
TITLE:

Production of new Ruthenium complexes with potential biological applications

KEY WORDS:

Ruthenium complexes; nitric oxide; heterocyclic ligands; interaction with DNA.

PAGES: 75
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Química Bio-Inorgânica
SUMMARY:

Ruthenium is a transition metal that has gained prominence in inorganic and medicinal chemistry due to its structural and biological properties. Ruthenium complexes containing heterocyclic ligands and nitric oxide have demonstrated promising antitumor, antibacterial, and antiviral activities, supporting the advancement of these compounds toward clinical trial phases. Furthermore, many of these complexes exhibit the ability to interact with biomolecules, particularly DNA, promoting cleavage processes that may impair cellular replication and contribute to their biological effects. This work proposes the synthesis, characterization, and evaluation of the DNA cleavage ability of three new complexes of the type cis-[Ru(bpy)(phen)(L)n](PF6)n, where L represents the ligands NO and/or Amtz = 2-amino-5-trifluoromethyl-1,3,4-thiadiazole, 4-Clpy = 4-(4-chlorobenzoyl)pyridine, bpy = 2,2′-bipyridine, and phen = 1,10′-phenanthroline. The complexes were obtained by dissolving the precursor complex cis-[Ru(bpy)(phen)Cl₂] in a water–ethanol mixture, followed by the addition of the auxiliary ligands. Through UV–Vis absorption spectroscopy in methanol, it was possible to identify the intraligand bands of the heterocyclic ligands, as well as the metal-to-ligand charge transfer (MLCT) bands involving the heterocyclic ligands and the nitrosyl ligand in the range of 320–470 nm.Regarding the vibrational spectra obtained using KBr pellets, the complexes exhibited characteristic stretching and bending modes that were important for identifying the coordination of the ligands to the metal center, associated with C=C, C=N, C=O, C–H, C–F, and ν(NO⁺) bonds. In addition, the cyclic voltammograms of the complexes cis-[Ru(bpy)(phen)(Amtz)2](PF6)2, cis-[Ru(bpy)(phen)(4-Clpy)2](PF6)2 and cis-[Ru(bpy)(phen)( 4-Clpy)NO](PF6)3 showed E₁/₂ values of 617 mV, 640 mV, and 377 mV, respectively. For the first two complexes, the observed redox processes were attributed to the Ru³⁺/Ru²⁺ redox couple, whereas for the nitrosyl complex, the E₁/₂ value was associated with the NO⁺/NO⁰ redox couple. The DNA cleavage ability of the complexes was evaluated using pBR322 plasmid DNA at different concentrations, under both dark conditions and blue-light irradiation, in order to investigate the influence of photoactivation on the interaction between the synthesized compounds and DNA.

COMMITTEE MEMBERS:
Interno - 1715109 - DANIEL DE LIMA PONTES
Interno - 1959889 - DAVI SERRADELLA VIEIRA
Externo ao Programa - 1945343 - FRANCISCO ORDELEI NASCIMENTO DA SILVA - null