Data Sheet 1_Antibacterial potential of mono- Ru(II) and bi-metallic Ru(II)-Mn(II) inorganic compounds with phosphino-fluoroquinolone conjugates.docx

Herein, we present two novel heterobimetallic complexes Ru(II)-Mn(II) (Ru(η6-p-cymene)Cl2PCpMnCl2(H2O)2 (RuPCpMn) and Ru(η6-p-cymene)Cl2PNrMnCl2(H2O)2 (RuPNrMn)) with phosphines (PCp, PNr) derived from fluoroquinolones antibiotics (HCp–ciprofloxacin and HNr–norfloxacin). Compounds were characterized using elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), electron paramagnetic resonance (EPR), electronic absorption spectroscopy (UV-Vis), and electrospray ionization mass spectrometry (ESI-MS). The antibacterial activity in vitro of heterobimetallic complexes together with literature monometallic CuI and RuII complexes possessing the same and different phosphine ligands was evaluated. The results indicate that structural modifications of metal-fluoroquinolone complexes affect their antibacterial properties. The mononuclear ruthenium(II) complexes exhibited broad-spectrum activity, particularly against Gram-negative bacteria, whereas the incorporation of manganese(II) ions did not lead to substantial improvement of antibacterial activity in vitro. However, complexes containing phosphine ligands without fluoroquinolone motifs but with, e.g., alkaloid, exhibited significantly reduced activity, emphasizing the importance of maintaining the pharmacophoric integrity of the fluoroquinolone core.