New Mononuclear and Binuclear Cu(II), Co(II), Ni(II), and Zn(II) Thiosemicarbazone Complexes with Potential Biological Activity: Antimicrobial and Molecular Docking Study

Herein, we report the synthesis of eight new mononuclear and binuclear Co2+, Ni2+, Cu2+, and Zn2+ methoxy thiosemicarbazone (MTSC) complexes aiming at obtaining thiosemicarbazone complex with potent biological activity. The structure of the MTSC ligand and its metal complexes was fully characterized by elemental analysis, spectroscopic techniques (NMR, FTIR, UV-Vis), molar conductivity, thermogravimetric analysis (TG), and thermal differential analysis (DrTGA). The spectral and analytical data revealed that the obtained thiosemicarbazone-metal complexes have octahedral geometry around the metal center, except for the Zn2+-thiosemicarbazone complexes, which showed a tetrahedral geometry. The antibacterial and antifungal activities of the MTSC ligand and its (Co2+, Ni2+, Cu2+, and Zn2+) metal complexes were also investigated. Interestingly, the antibacterial activity of MTSC- metal complexes against examined bacteria was higher than that of the MTSC alone, which indicates that metal complexation improved the antibacterial activity of the parent ligand. Among different metal complexes, the MTSC- mono- and binuclear Cu2+ complexes showed significant antibacterial activity against Bacillus subtilis and Proteus vulgaris, better than that of the standard gentamycin drug. The in silico molecular docking study has revealed that the MTSC ligand could be a potential inhibitor for the oxidoreductase protein.Taif UniversityPeer Reviewe

Synthesis, Spectroscopic Characterization, and Biological Activities of New Binuclear Co(II), Ni(II), Cu(II), and Zn(II) Diimine Complexes

Metal-ligand complexes have attracted major interest due to their potential medical applications as anticancer agents. The work described in the current article aimed to synthesize, spectroscopic, thermal, and biological studies of some metal-diimine complexes. A diimine ligand, namely 2-{[2-(4-chlorophenyl)-2-hydroxyvinyl]-hydrazonomethyl}phenol (diim) was prepared via the reaction of p-chlorophenacyl bromide with hydrazine hydrate in ethanol, then condensation was completed with 2-hydroxybenzaldehyde in acetic acid. The Co(II), Ni(II), Cu(II), and Zn(II) complexes were prepared with a metal:ligand stoichiometric ratio of (2:1). 1H-NMR, UV-Vis, FTIR spectroscopic data, molar conductivity measurements, and microanalytical data (carbon, hydrogen, nitrogen, and halogen) were used for characterization of the formed ligand and its metal complexes. It was found that the diimine ligand act as tetradentate fashion. The non-electrolytic character for all the complexes was proved by molar conductivity. The first metal atom of the synthesized binuclear diimine complexes coordinates with the nitrogen of hydrazine group and oxygen of OH group. While, the second metal atom coordinates with the other nitrogen atom of the hydrazine group and oxygen of phenolic group. All the synthesized metal complexes have a six-coordinated except for Zn(II) has four-coordinated. Thermogravimetric analysis and its differential analysis were done to discuss the thermal degradation of the free ligand and its metal complexes. Molecular docking calculation showed that the diimine ligand is a good inhibitor for breast cancer 3hb5 and 4o1v kidney cancer proteins. Additionally, these compounds were evaluated as antibacterial and antifungal agents