Anticancer activity and DNA interaction of ruthenium acetate clusters bearing azanaphthalene ancillary ligands

This work shows six triruthenium complexes regarding their cytotoxicity toward murine melanoma (B16F10) and human lung cancer (A549) models, and their interactions with fish sperm DNA (fs-DNA) and pUC19 DNA. From 2 to 200 uM, these complexes reduced B16F10 cell viability. We resolved the structure of complex 4 through single-crystal x-ray crystallography. Complexes 4 and 6 showed values for IC50 of 10 and 50 uM, respectively, being much less toxic to L929 non-tumoral cells at these concentrations. Ethidium bromide (EB) displacement tests showed that complex 5 was able to intercalate DNA with the greatest intercalating constant, Kapp, of 12.5 x 10^5 M-1, and it also had a high binding constant measured via spectrophotometric titration with fs-DNA (Kb = 6.3 x 10^4 M-1). Incubation of complexes with pUC19 DNA showed no cleavage of DNA, as compared to positive control, cisplatin.