Synthesis, spectral characterization and biological investigation of new organoruthenium(II) complexes with N, X-donor (X = S, O) heterocyclic chelators

Abstract

New Ru(II) arene complexes containing 2,4-dihydroxyacetophenone based Schiff bases have been synthesized and characterized with FTIR, UV–visible, 1H NMR, 13C NMR and mass spectroscopies. Spectroscopic analysis revealed that the ligands coordinated to ruthenium(II) in a monobasic bidentate fashion via azomethine nitrogen and thiolate/oxalate. Antimicrobial activities of the compounds were evaluated with two bacteria (Staphylococcus aureus and Pseudomonas aeruginosa) and two fungi (Candida albicans and Candida tropicalis). The complexes displayed better antimicrobial activity over their ligands. In addition, the ligands and the complexes were analyzed for their anticancer potential against A549 (human lung carcinoma) and HeLa (human cervical cancer) cells, in which the complexes exhibited comparable activities against A549 (IC50 value is 21 ± 1 µM (1), 18 ± 1 µM (2)) and HeLa (IC50 value is 22.1 ± 0.9 µM (1), 20 ± 1 µM (2)) with the standard drug cisplatin (IC50 value is 25 ± 1 µM (A549) and 27 ± 1 µM (HeLa)). The non-toxic nature of the compounds has been confirmed with human umbilical vein endothelial cells (HUVEC cells). The obtained results highlighted the possibility of developing ruthenium arene complexes as anticancer agents.