New zinc(II) complexes of the Non-steroidal Anti-Inflammatory Drug (indomethacin) and various nitrogen donor ligands. Synthesis, characterization and biological activity

A series of complexes of Zn(II), [Zn2(Indo)4] 1, [Zn2(indo)4(pico)2] 2, [Zn(indo)2(apy)2] 3, [Zn(indo)2(ampy)] 4, [Zn(indo)2(phen)] 5, [Zn(indo)2(dmph)] 6, [Zn(indo)2(admp)2] 7, (indo = indomethacin, apy = 2-amino pyridine, dmph = 2,9-dimethyl-1,10-phenanthroline, pico = 3-picoline, ampy = 2-aminomethyl pyridine, phen = 1,10-phenanthroline, admp = 2-amino-4,6-dimethylpyrimidine) were synthesized and characterized using IR, UV–Vis, 1HNMR, 13C{1H}NMR spectroscopic techniques in order to examine their binding coordination modes in addition to their biological activity. The crystal structures of complex 2 was determined by single crystal X-ray diffraction, showing binuclear complex with two 3-picoline groups one for each Zn(II) center, and four indomethacin molecules, two of them were bidentate chelating, one was bidentate bridging, and the other was monodentate terminal bridging.In-vitro anti-bacterial activities of the complexes were screened using agar diffusion method against two gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes) and two gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa). Most of the complexes showed anti-bacterial effects against P. aeruginosa, and S. aureus while they were inactive toward E. coli and L. monocytogenes. Complexes 1–4 showed higher activity upon complexation against P. aeruginosa and S. aureus than their parent ligands. Complex 5 showed decreased activities upon complexation against all tested bacteria except against P. aeruginosa were it was inactive. Complex 6 showed decreased activity against S. aureus, but its activity was not affected by complexation against P. aeruginosa. Complex 7 showed higher activity against S. aureus, and no activity against P. aeruginosa.

This work report synthesis and spectroscopic characterization of mixed ligand Zn(II) complexes of indomethacin and aromatic nitrogen based ligands. The crystal structure of complex 2 was determined using single-crystal X-ray diffraction.In-vitro anti-bacterial activity of the prepared complexes and their parent ligands were investigated against different Gram-positive and Gram-negative bacteria using agar diffusion method.Figure optionsDownload as PowerPoint slide