Transition metal(II) complexes with the non-steroidal anti-inflammatory drug oxaprozin: Characterization and biological profile.

A series of copper(II), nickel(II) and cobalt(II) complexes with the non-steroidal anti-inflammatory drug oxaprozin (Hoxa) have been synthesized and characterized by diverse techniques. The crystal structures of two copper(II) complexes, namely the dinuclear complex [Cu2(oxa)4(DMF)2] (1) and the polymeric complex {[Cu2(oxa)4]·2MeOH·0.5MeOH}2 (12) were determined by single-crystal X-ray diffraction studies. In order to evaluate in vitro the antioxidant activity of the resultant complexes, their scavenging ability towards 1,1-diphenyl-picrylhydrazyl (DPPH), hydroxyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals was investigated revealing their high effectiveness against these radicals. The binding of the complexes to bovine serum albumin and human serum albumin was examined and the corresponding determined albumin-binding constants showed a tight and reversible interaction. The interaction of the complexes with calf-thymus DNA was monitored by diverse techniques including UV-vis spectroscopy, cyclic voltammetry, DNA-viscosity measurements and competitive studies with ethidium bromide. Intercalation may be proposed as the most possible DNA-interaction mode of the complexes.

Metal Complexes with Naphthalene-Based Acetic Acids as Ligands: Structure and Biological Activity.

Naproxen (6-methoxy-α-methyl-2-naphthaleneacetic acid), 1-naphthylacetic acid, 2-naphthylacetic acid and 1-pyreneacetic acid are derivatives of acetic acid bearing a naphthalene-based ring. In the present review, the coordination compounds of naproxen, 1- or 2-naphthylacetato and 1-pyreneacetato ligands are discussed in regard to their structural features (nature and nuclearity of metal ions and coordination mode of ligands), their spectroscopic and physicochemical properties and their biological activities.

Transition metal complexes with a novel guanine-based (E)-2-(2-(pyridin-2-ylmethylene)hydrazinyl)quinazolin-4(3H)-one: Synthesis, characterization, interaction with DNA and albumins and antioxidant activity.

A novel guanine-inspired 2-hydrazinyl-4(3H)-quinazolinone derivative (HL) has been synthesized and characterized. The reaction of HL with Cu(II) in a 1:1 M:L ratio and with Cu(II), Ni(II) and Zn(II) in a 1:2 M:L ratio resulted in the formation of complexes, [Cu(L)(H2O)2](NO3), 1 and [M(L)2] (M = Cu for 2, Ni for 3 and Zn for 4), respectively. In all these complexes, the ligand L is tridentately bound to the corresponding metal. The affinity of the complexes for calf-thymus DNA was examined by diverse techniques and the complexes can intercalate between the DNA-bases. The cleavage ability of the complexes towards supercoiled circular pBR322 plasmid DNA was examined via agarose gel electrophoresis experiments in the absence or presence of UVA, UVB or visible light and the DNA-cleavage was found to depend on the concentration and light wavelength used. The binding of the complexes for bovine and human serum albumins was also investigated in order to determine the binding constants and the binding subdomain. The scavenging activity of the compounds was evaluated towards free radicals 1,1-diphenyl-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid).

Manganese(II) coordination compounds of carboxylate non-steroidal anti-inflammatory drugs.

Upon the interaction of MnCl2 with the non-steroidal anti-inflammatory drugs oxaprozin or flufenamic acid in the presence of the nitrogen-donors 2,2'-bipyridine or 1,10-phenanthroline as co-ligands, one dinuclear and two trinuclear Mn(II) complexes were isolated. The complexes were characterized by diverse techniques. The complexes were evaluated for their scavenging activity against free radicals such as hydroxyl, 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid). The in vitro binding affinity of the complexes to calf-thymus (CT) DNA and serum albumins was also monitored. In total, we may suggest that the complexes present promising scavenging activity against the radicals tested, and they may bind to CT DNA via intercalation and reversibly to serum albumins.

Organometallic rhenium tricarbonyl-enrofloxacin and -levofloxacin complexes: synthesis, albumin-binding, DNA-interaction and cell viability studies.

Organometallic rhenium complexes have recently been considered in the development of novel antitumor agents due to their suitable properties. A series of rhenium(I) tricarbonyl complexes was synthesized with the quinolone antimicrobial agents enrofloxacin (Herx) and levofloxacin (Hlfx) and solvent (e.g., methanol), imidazole (im) or pyridine (py) as co-ligands. The complexes were characterized by spectroscopic methods. The interaction of the rhenium complexes with bovine serum albumin was investigated by fluorescence emission spectroscopy and the corresponding binding constants were determined. The binding of the rhenium complexes to calf-thymus DNA was monitored by UV-Vis spectroscopy, viscosity measurements and competitive studies with ethidium bromide. These studies indicated that intercalation is the most possible mode of action and the corresponding DNA-binding constants of the complexes were calculated. The cytotoxicity of the Re-complexes against human K-562 erythroleukemia cells was found to be moderate to high. These preliminary results are promising and warrant the design of new Re-complexes with improved properties in future studies.

Zinc-oxaprozin compounds: Synthesis, structure and biological activity.

Four novel zinc complexes, namely [Zn(oxa)2(MeOH)4] (1), [Zn(oxa)2(H2O)(bipy)]·MeOH·2.5H2O (2·MeOH·2.5H2O), [Zn(oxa)2(bipyam)]·1.25MeOH (3·1.25MeOH) and [Zn(oxa)2(phen)] (4), with the non-steroidal anti-inflammatory drug oxaprozin (Hoxa) and a N,N'-donor heterocyclic ligand, such as 2,2'­bipyridylamine (bipyam), 1,10­phenanthroline (phen) or 2,2'­bipyridine (bipy), were characterized with physicochemical techniques, various spectroscopies and single-crystal X-ray crystallography. In these coordination compounds, the oxaprozin ligands are coordinated to zinc ion in a monodentate or a bidentate chelating binding mode. The antioxidant activity of the complexes was evaluated via their ability to scavenge in vitro 1,1­diphenyl­2­picrylhydrazyl, hydroxyl and 2,2'­azinobis­(3­ethylbenzothiazoline­6­sulfonic acid) radicals. The complexes bind to calf-thymus DNA via intercalation as suggested via a series of studies employing UV-vis spectroscopy, DNA-viscosity measurements and competition with ethidium bromide. The complexes may bind to serum albumins tightly and reversibly in order to get transferred through the bloodstream.