Anomalous chemosensitivity of SOD mimetic sulfurated amino acid–phen complexes: synthesis, characterization, and DNA cleavage efficacy

Abstract

The DNA interaction efficacies of mixed-ligand complexes [ML(phen)2]Cl [L = a Schiff base derived from p-substituted benzaldehyde (L1 = NO2/L2 = –OCH3) and methionine; phen = 1,10-phenanthroline, the co-ligand] have been explored by absorption, electrochemistry, viscosity measurements, and agarose gel electrophoresis. The results indicate that these complexes can bind to calf thymus DNA via an intercalative mode and show efficient cleavage activity in the presence of H2O2. They are dose dependent. The antioxidative properties reveal that one complex has a stronger radical-scavenging potency than ligands. The complexes exhibit superoxide dismutase (SOD)-like activity with their IC 50 values ranging from 0.46 to 2.93 µM. Moreover, all the complexes have shown relatively high antibacterial and antifungal potencies. The in vitro chemosensitivity of the studied complexes exhibits significant cytotoxic effects, comparable to those reported for cisplatin. These findings represent a prompting to search for the probable interaction of these complexes with other cellular elements of fundamental consequence in cell proliferation.