Example of two novel thiocyanato bridged copper (II) complexes derived from substituted thiosemicarbazone ligand: structural elucidation, DNA/albumin binding, biological profile analysis, and molecular docking study.

Two novel copper (II) substituted thiosemicarbazone Schiff base complexes Cu(L)(µ-SCN) () and Cu(µ-SCN)(SCN)(L) () have been synthesized by condensing substituted thiosemicarbazides like 4-methyl-3-thiosemicarbazide or 4-ethyl-3-thiosemicarbazide with 2-acetylpyridine. Both the metal complexes and are characterized using different spectroscopic techniques like IR, UV-Vis, ESR spectroscopy followed by elemental analysis, cyclic voltammetric measurement and single crystal X-ray structure analysis. X-ray crystal structure analysis reveal that complex is polymeric while complex is dimeric in nature. The coordination geometry around Cu(II) are square pyramidal in which thiosemicarbazone Schiff base ligand coordinate to the central Cu(II) atom in tridentate fashion. The prominent interaction patterns of and with CT-DNA were examined by employing electronic absorption and emission spectral titrations, cyclic voltammetry and viscosity measurements. All the results show that CT-DNA binds with both copper (II) complexes and . Furthermore, protein binding ability in vitro of complexes and with both BSA and HSA were carried out using multispectroscopic techniques and a static quenching pattern was observed in both cases. Molecular docking study was employed to ascertain the exact mechanism of action of and with DNA and protein molecules (BSA and HSA). In vitro cytotoxicity activity of complexes and toward AGS and A549 was evaluated using MTT assay which demonstrates that both complexes and have superior prospectus to act as anticancer agents. Communicated by Ramaswamy H. Sarma.