DNA binding, antitubercular, antibacterial and anticancer studies of newly designed piano-stool ruthenium(II) complexes.

The chemotherapeutic potential of ruthenium(II) complexes has recently attracted researchers' interest as antibacterial and anticancer agents. In this study, two novel half-sandwich imine-based Ru complexes ([Ru( p -cymene)Cl(L-1)][PF 6 ] (Ru-1) and [Ru( p -cymene)Cl(L-2)][PF 6 ] (Ru-2)) were reported for their deoxyribonucleic acid (DNA) binding and antitubercular, antibacterial, and anticancer activities. The molecular structure of Ru-2 was obtained by single-crystal X-ray crystallography. DNA interaction studies were conducted by UV-Vis absorbance and fluorescence spectral titration which gave rise to DNA binding constants ( K b ) of 1.32 × 10 6 and 1.82 × 10 6 for Ru-1 and Ru-2, respectively and the Stern-Volmer binding constant ( K SV ) values for Ru-1 and Ru-2 were 1.7763 × 10 4 M -1 and 7.6 × 10 3 M -1 , respectively. The in vitro antitubercular activity was evaluated against Mycobacterium tuberculosis H37Ra. The antibacterial potential of both the Ru-complexes was examined against Gram-negative ( Escherichia coli and Pseudomonas aeruginosa ) and Gram-positive ( Staphylococcus aureus and Bacillus subtilis ) bacteria. The half-maximal inhibitory concentration (IC 50 ) values for the antitubercular activity of Ru-1 and Ru-2 were 4.87 ± 1.32 μM and 5.78 ± 0.54 μM, respectively. A cytotoxic study of these complexes was performed against the human breast cancer cell line (MCF-7) and the human embryonic kidney cell line (HEK293) (normal cells). The study revealed meaningful activity of the Ru-1 complex against (cancer) MCF-7 cells, while the viability of HEK293 (normal) cells in the presence of Ru-2 was higher as compared to a reference drug 5FU. We suggest that these kinds of Ru-complexes could have potential for application in metallopharmaceuticals.