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), 1,10‑phenanthroline (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 1,1‑diphenyl‑2‑picrylhydrazyl, hydroxyl and 2,2'‑azinobis‑(3‑ethylbenzothiazoline‑6‑sulfonic 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.