Synthesis, characterization and biological evaluation of novel ruthenium(II)-polypyridine mixed ligand complexes bearing 1,2,4- triazole-thiol moiety

Abstract

The novel mixed ligand complexes [Ru(bpy)2(pytrzSH)2](PF6)2 (complex A) and [Ru(phen)2(pytrzSH)2](PF6)2 (complex B) (bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline and pytrzSH = 5-(3-pyridyl)-4H-1,2,4-triazole-3-thiol) has been synthesized and characterized by elemental analysis, UV, FTIR, 1H NMR, 13C NMR and MALDI-TOF mass spectral techniques. The spectral data confirms the formation of octahedral complexes. The lipophilic nature of the complex is determined from the partition coefficient (log P) values and it is found to be 1.20 ± 0.004 for complex A and 1.86 ± 0.004 for complex B. The synthesised complexes show slight antimicrobial activities on S. aureus, P. aeruginosa, E. coli, A. niger and C. albicans. The α-glucosidase inhibitory activity of the synthesised complexes A and B against the positive control acarbose display IC50 value at 490.32 and 223.01 µg/mL. In vitro antiproliferative and cytotoxic effects of complexes A and B are analysed on SK-MEL-28 and non-tumoral L6 cell lines by microscopic and MTT assay methods. The IC50 for complexes A and B on SK-MEL-28 cancerous cell line are found to be 27.444 and 40.721 µg/mL and for non-tumoral L6 cells are 25.869 and 38.425 µg/mL respectively. The apoptotic study suggests that the synthesized complexes show late apoptotic effect on SK-MEL-28 cancerous cells and early apoptotic effect on non-tumoral L6 cells. Hence the obtained results suggest that the biological activities of the synthesised complexes depend on the nature of the ligands present in the complexes.