Photochemical effects and interactions with non-canonical DNA structures of a diazafluorenone-based ruthenium compound

An new ruthenium complex containing phenyl-terpyridine and diazafluorenone ligands, [Ru(DFO)(phtpyCl)Cl](PF6) (MPD4) was synthesized, characterized, and studied as a potential agent for aPDT. Photochemical studies were carried out, such as those with the DPBF probe, which showed evidence of production of singlet oxygen under blue LED irradiation. Besides these studies, an investigation on the interaction of MPD4 with non-canonical DNA structures was conducted employing circular dichroism spectroscopy (CD), aiming to identify any specific interactions with key sequences associated with a series of pathologies, including cancer. In addition, microbiological studies were done (MIC, MBC and biofilm formation), indicating an enhanced effect even upon red light irradiation against Gram positive and Gram-negative bacteria as well as a synergistic activity in combination with commercial antimicrobial agents. Altogether, these results support that further biological studies must be conducted to better elucidate its full pharmacological potential.