Hijazi Abu Ali

Synthesis, characterization and antimicrobial activity of zinc(II) ibuprofen complexes with nitrogen-based ligands

Abstract Metal carboxylate complexes possess different carboxylate coordination modes, e.g. monodentate, bidentate, and bridging bidentate. Five Zn(II) complexes were prepared and characterized in order to examine their coordination modes in addition to their biological activity. The syntheses were started by preparation of [Zn(ibup)2(H2O)2] (1). Then, different nitrogen-donor ligands reacted with 1 to produce [Zn(ibup)2(2-ampy)2] (2), [Zn(ibup)(2-ammethylpy)] (3), [Zn(ibup)(2,2′-bipy)] (4), and [Zn2(ibup)4(2-methylampy)2] (5) (ibup = ibuprofen, 2-ampy = 2-aminopyridine, 2-ammethylpy = 2-aminomethylpyridine, 2,2′-bipy = 2,2′-bipyridine, 2-methylampy = 2-(methylamino)pyridine). IR, 1H NMR, 13C{1H}-NMR and UV–vis spectroscopies were used for characterization. The crystal structures of 2 and 5 were determined by single-crystal X-ray diffraction. Investigation of in vitro antibacterial activities for the complexes against Gram-positive (Micrococcus luteus, Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis) bacteria were done using agar well-diffusion method. Complex 1 showed antibacterial activity against Gram-positive bacteria. Complexes 2 and 3 did not exhibit antibacterial activity. Complex 4 showed antibacterial activity and was chosen for further studies to determine the inhibition zone diameter for different concentrations and to set the minimum inhibitory concentration. The antibacterial activity against most of the bacteria was minimized as a result of the complexation of zinc ibuprofen with 2,2′-bipy in 4.

Dichloro-bis-(pyridine-2-yl-undecyl-amine)zinc(II), [ZnCl2(C16N2H26)2]: Synthesis, characterization and antimalarial activity

Abstract A nitrogen-based ligand (pyridine-2-yl-undecyl-amine) (1) was synthesized and used for the synthesis of a Zn(II) compound (dichloro-bis(pyridine-2-yl-undecyl-amine)zinc(II)) (2). Compound 2 was synthesized and characterized using IR, 1H NMR, and 13C{1H} NMR spectroscopy. The crystal structure of 2 was determined using single-crystal X-ray crystallography. The compound was tested for its anti-malarial activity using two methods, a semi-quantitative micro-assay and a previously self-developed quantitative in vitro method. Both methods were used to study the efficiency of 2 to inhibit the formation of the malaria pigment considered an important target of many anti-malarial drugs such as chloroquine and amodaquine. The efficiency of 2 to prevent the formation of β-hematin was 71.4%. The efficiency of amodiaquine as a standard drug was reported at 93.8%.

New Zn(II) complexes based on biologically active substituted acetic acid and nitrogen donor ligands: synthesis, crystal structure and biological applications

Abstract The complexes [Zn(phenylacetato)2(2-aminopyridin)2] (3), [Zn(phenylacetato)2(1,10-phenanthroline)]·H2O (4), and [Zn(phenylacetato)2(2,9-dimethyl-1,10-phenanthroline)]·0.5 H2O (5) were prepared and characterized by IR-, UV–Visible, 1H and 13C NMR spectroscopy, and single crystal X-ray diffraction. BNPP hydrolysis of the complexes and their parent nitrogen ligands showed that the hydrolysis rate of bis-(4-nitrophenyl) phosphate (BNPP) was 1.7 × 105 L mol−1 s−1 for 3, 3.1 × 105 L mol−1 s−1 for 4 and 4.3 × 104 L mol−1 s−1 for 5. Antibacterial activities show the effect of complexation on activity against Gram-positive (S. epidermidis, S. aureus, E. faecalis, M. luteus and B. subtilis) and Gram-negative (K. pneumonia, E. coli, P. mirabilis and P. aeruginosa) bacteria using the agar well diffusion method. Complex 4 showed good activity against G− bacteria except P. aeruginosa, and against G+ bacteria except E. ferabis. Complex 5 showed no activity against G− bacteria, low activity against M. luteus and B. subtilis bacteria and high activity against S. epidemidis and S. aureus. Complex 3 did not show any activity against G− or G+ bacteria.

New complexes of Zn(II) with the anti-inflammatory non-steroidal drug, ibuprofen and nitrogen donor ligands. Synthesis, characterization and biological activity

Abstract Complexes of [Zn(ibup)2(4,4′-bipy)]n 1, [Zn(ibup)2(phen)] 2, [Zn(ibup)2(2,9-dmphen)] 3, [Zn(ibup)2(1,2-dmimidazole)2] 4, and [Zn(ibup)2(2-am-6-picoline)2] 5 (ibu = ibuprofen, 4,4′-bipy = 4,4′-bipypyridine, phen = 1,10-phenanthroline, 2,9-dmephen = 2,9-dimethyl-1,10-phenanthroline, 1,2-dmimidazole = 1,2-dimethylimidazole, and 2-am-6-picoline = 2-amino-6-picoline) were prepared and characterized. The crystal structure of 1 was determined by single-crystal X-ray diffraction. The in vitro anti-bacterial activities for the complexes against Gram-positive (Micrococcus luteus, Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli, Klebsiella pneumonia and Proteus mirabilis) bacteria were done using the agar well-diffusion method. Complexes 1–3 showed anti-bacterial activity against Gram-positive bacteria, while 4 and 5 did not exhibit anti-bacterial activity. Complexes 2 and 3 were selected for further studies. Complexation of zinc-ibuprofen with phen as in 2 decreased the anti-bacterial activity against most of the bacteria used. The complexation in 3 decreased the anti-bacterial activity in Gram-positive bacteria but for Gram-negative bacteria, the overall anti-bacterial activity of uncoordinated 2,9-dmphen was enhanced upon coordination with zinc ibuprofen.