Novel piplartine-containing ruthenium complexes: synthesis, cell growth inhibition, apoptosis induction and ROS production on HCT116 cells Novel piplartine-containing ruthenium complexes: synthesis, cell growth inhibition, apoptosis induction and ROS production on HCT116 cells

Ruthenium(II) diclofenac-based complexes of the general formula [Ru(dicl)(P–P)(bpy)]PF₆ [dicl = diclofenac, bpy = 2,2′-bipyridine, and P–P = 1,4′-bis(diphenylphosphino)butane (dppb) (1), 1,2′-bis(diphenylphosphino)ethane (dppe) (2), 1,3′-bis(diphenylphosphino)propane (dppp) (3) and 1,1′-bis(diphenylphosphino)ferrocene (dppf) (4)] are synthesized. The complexes (1–4) are characterized by elemental analyses, infrared, NMR, and UV-vis spectroscopy and (3) and (4) are characterized by single crystal X-ray diffraction. The DNA binding of complexes (1–4), studied by circular dichroism (CD) and Hoechst 33 258 staining assay, indicates their binding with the minor grooves. The complexes interact with BSA with binding constants (K_b) in the range of 2.5 × 10³–5.5 × 10⁴ M⁻¹. The complexes exhibit high cytotoxicity against the tumor cell lines A549, MDA-MB-231, and MCF-7 with IC₅₀ values ranging from 0.56 to 15.28 μM. The complexes are more selective for the hormone-dependent MCF-7 breast tumor cell line and complex (1) is the most potent one. The study demonstrates the anticancer activity of ruthenium(II)/diclofenac-based complexes.