Cytotoxicity and antimicrobial activity of platinum(II) complexes based on the ligand precursor 2-phenyl-6-(1,2,3-triazol-4-yl)pyridine – influence of substituent and ancillary ligand on selectivity and activity

The development of metal-based anticancer agents has been a significant area of research since the discovery of cisplatin’s cytostatic effects. In this study, we investigate the cytotoxicity of tridentate ligands derived from 2-phenyl-6-(1,2,3-triazol-4-yl)pyridine and their platinum(II) and palladium(II) complexes against various human cancer cell lines and normal fibroblasts. Several complexes exhibit high cytotoxicity, particularly against acute T-lymphoblastic leukemia cells (CCRF-CEM). Notably, a platinum(II) complex containing an acylpyrrolidine ligand demonstrates remarkable cancer cell selectivity with a sub-micromolar IC 50 value of 0.17 μM. Cell cycle analysis revealed that these compounds induce apoptosis and affect DNA/RNA synthesis. Additionally, some complexes show significant antimicrobial activity against Gram-positive bacteria and yeast. Our findings highlight the potential of these metal complexes as selective anticancer agents and underscore the importance of further mechanistic studies.