Synthesis, spectroscopic, DFT calculations, antimicrobial, cytotoxicity, and DNA binding studies of novel Cu (II), Ni (II), Zn (II), and VO (II) Schiff base complexes based on ibuprofen

The ibuprofen Schiff base ligand (HL) [HL=2-(4-Isobutyl-phenyl)-propionic acid (3-hydroxy-naphthalen-2-ylmethylene)-hydrazide] and its Cu (II), Ni (II), Zn (II), and VO (II) chelates were synthesized and characterized. The spectral data revealed that the Schiff base ligand HL coordinated to Cu (II), Ni (II), Zn (II), and VO (II) via azomethine nitrogen and phenolic oxygen. NiL and CuL have square planar geometry, ZnL has octahedral geometry, and VOL has square pyramidal geometry. Density functional calculations (DFT) were performed to examine the molecular geometry. The results of continuous variation and molar ratio methods supported the ratio of (M:L) to be (1:1). The antimicrobial activity of the new Ibuprofen Schiff base ligand and its metal complexes was tested in vitro against bacterial pathogens and fungi. The results revealed that the antimicrobial efficacy follows the order: CuL is the highly inhibitor complex compared with ketoconazole and gentamicin as reference drugs. The in vitro cytotoxic activity of the new ligand and its complexes was also investigated against Hep-G2, MCF-7, and HCT-116 cell lines. The results showed again that CuL is the highest active agent compared with Vinblastine drug. The CT-DNA binding ability of the studied complexes was evaluated by absorption spectroscopic titrations and gel electrophoresis. The results showed that the complexes have good binding propensity, and their binding constant values were from 3.1 x 10(5) to 6.1 x 10(5) M-1.