Novel Ruthenium‐based Nitrosyl Complexes: NO Donation and Vasorelaxant Potentials for Cardiovascular Therapeutics

Nitrosyl ruthenium complexes have emerged as promising platforms for the controlled delivery of nitric oxide (NO) and nitroxyl (HNO), both of which possess significant therapeutic implications. Considering this scenario, we synthesized and characterized the metal complex cis-[RuNO(phen)2(2MIM)]3+ and its precursors, where phen and 2MIM correspond to 1,10-phenantroline and 2-methylimidazole, respectively. Comprehensive structural elucidation was undertaken using a combination of spectroscopic and electrochemical methodologies, including XANES/EXAFS experiments. This structural data was further validated through DFT computational analyses. We demonstrated that such compound can release NO and HNO in the presence of thiol-based substrates. Not only this, but the same metal complex can also delivery nitric oxide under irradiation with visible light (λ=460 nm). The nitrosyl complex and its derivatives displayed marked vasodilatory capabilities as evidenced in assays involving isolated rat aorta rings. They also exhibited commendable antioxidant activity in free radical scavenging assays. Collectively, based on these data, this nitrosyl ruthenium compound is a potential therapeutic candidate, especially in the field of cardiovascular pathology like atherosclerosis, thereby deserving further in-depth investigations.