Ru(II) organometallic complexes: in vitro cytotoxic activity against K562 chronic myeloid leukemia cells and interactions with DNA and BSA

Four cationic arene Ru(II) complexes containing mono- and bidentate N,S-donor ligands were synthesized and characterized by spectroscopic, spectrometric, and conductivity techniques. Single-crystal X-ray diffraction structures were determined for the series 2 complexes. Their interactions with DNA and bovine serum albumin (BSA) were investigated by fluorescence spectroscopy and molecular docking. The complexes exhibited weak DNA binding without intercalation but showed strong affinity toward BSA. Preliminary in vitro cytotoxicity assays against chronic myeloid leukemia (K562) cells revealed potent activity (IC₅₀ = 0.40–1.05 µM), surpassing cisplatin, whereas the free ligands and precursor complexes were inactive. These findings demonstrate the potential of the synthesized Ru(II) complexes as promising antitumor candidates with favorable biomolecular interaction profiles.