Synthesis, biological-pharmacological evaluation and molecular docking studies of Schiff base analogues of transition metal (II) complexes of 4-amino-1,5dimethyl-2-phenylpyrazol-3-one

Novel tridentate Schiff base [CuL2], [NiL2], [CoL2], [MnL2] and [ZnL2] complexes have been prepared with Schiff base resulting from acetophenylidene-4-iminoantipyrine and tyrosine. Microanalytical data, IR, UV-vis, 1H, 13C-NMR, powder XRD, SEM, cyclic voltammetry, ESR, and mass spectral techniques confirmed the structural features of the chelates. The general formula of the complexes [ML2] was confirmed from elemental analysis, mass and 1H-NMR spectral studies. Octahedral geometry of the chelates is confirmed by electronic absorption spectra and FT-IR spectra. The magnetic susceptibility and low conductance values reveal that the complexes are monomeric and non-electrolytic nature, respectively. Powder XRD and SEM images confirm the crystalline structure of the complexes. At 300 and 77 K, the X-band ESR spectra of [CuL2] complex in DMSO solution were recorded and their salient features have been reported. The binding of [CuL2] with CT-DNA study reveals that interactions occur through intercalation. Analgesic, anti-inflammatory and CNS activities and antimicrobial activities of Schiff base and its complexes reveal that the chelates have higher potent than free ligand. The molecular docking studies have been performed with DNA and 6COX enzyme using Hex 8.0 software which recognizes the biological activities and nature of binding of the complexes.

Automated summary

A series of novel tridentate Schiff base complexes were synthesized and characterized. The complexes exhibited higher biological activities and showed potential for drug development. Furthermore, the study on the binding properties of the complexes with DNA and enzymes can provide insights into their mechanisms of action in vivo.