Synthesis and characterization of Ni (II), Cu (II), Fe (II) and Fe 3 O 4 nanoparticle complexes with tetraaza macrocyclic Schiff base ligand for antimicrobial activity and cytotoxic activity against cancer and normal cells

This work describes a simple synthesis of complexes of the type [M(C32H28N4)Cl2], where M = Ni (II), Cu (II) and Fe (II) and a novel complex of magnetite nanoparticle (Fe3O4NP) inside (INS) tetraaza macrocyclic Schiff base ligand (C32H28N4): [Fe3O4NP‐INS‐(C32H28N4)], which was prepared by using a novel co‐precipitation method of coordinated ferric ion (Fe3+) in the complex [Fe(C32H28N4)Cl2] under mild conditions. The synthesized compounds were characterized and compared with a various physic‐chemical techniques like: Fourier transform infrared (FT‐IR), ultraviolet–visible spectroscopic techniques (UV–Vis), 1‐dimensional (1D) 1H‐NMR, 13C‐NMR spectroscopic techniques, mass spectra, Powder X‐ray diffraction (PXRD), Vibrating sample magnetometer (VSM), Scanning electron microscopy (SEM), elemental analysis and molar conductance measurements. Furthermore, the highest saturation magnetization was 26.56 emu.g−1 obtained from [Fe3O4NP‐INS‐(C32H28N4)] (diameter of Fe3O4NPs~20.87 nm) that prove easy separation by an external magnetic field. In vitro screening of all the compounds against different species of bacteria and fungi shows that [Fe3O4NP‐INS‐(C32H28N4)] is effective against the tested strains as compared to the tetraaza macrocyclic ligand and selected complexes. The cytotoxic activity of the all compounds was also examined in 3 human tumor cell lines as U87, MDA‐MB‐231 and LS‐174. The complex [Fe3O4NP‐INS‐(C32H28N4)] shows moderate and strong cytotoxic activity against brain cancer, colon cancer and breast cancer (U87, MDA‐MB‐231 and LS‐174 respectively), without showing cytotoxicity towards peripheral blood mononucleocyte (PBMC) cells.