Minimal Functionalization of Ruthenium Compounds with Enhanced Photoreactivity against Hard-to-Treat Cancer Cells and Resistant Bacteria.

Metallocompounds have emerged as promising new anticancer agents, which can also exhibit properties to be used in photodynamic therapy. Here, we prepared two ruthenium-based compounds with a 2,2'-bipyridine ligand conjugated to an anthracenyl moiety. These compounds coded and contain 2,2'-bipyridine or 1,10-phenathroline as auxiliary ligands, respectively, which provide quite a distinct behavior. Notably, compound exhibited remarkably high photoproduction of singlet oxygen even in water (ϕ = 0.96), almost twice that of (ϕ = 0.52). On the other hand, this latter produced twice more superoxide and hydroxyl radical species than , which may be due to the modulation of their excited state. Interestingly, exhibited a modest binding to DNA ( = 4.51 × 10), while did not show a measurable interaction only noticed by circular dichroism measurements. Studies with bacteria showed a great antimicrobial effect, including a synergistic effect in combination with commercial antibiotics. Besides that, showed very low or no cytotoxicity against four mammalian cells, including a hard-to-treat MDA-MB-231, triple-negative human breast cancer. Potent activities were measured for upon blue light irradiation, where IC of 43 and 13 nmol L were seen against hard-to-treat triple-negative human breast cancer (MDA-MB-231) and ovarian cancer cells (A2780), respectively. These promising results are an interesting case of a simple modification with expressive enhancement of biological activity that deserves further biological studies.