Neutral and cationic manganese(II)-diclofenac complexes: structure and biological evaluation

The interaction of MnCl2 with the non-steroidal anti-inflammatory drug sodium diclofenac in the presence of 2,2-bipyridine and pyridine resulted in the formation of cationic and neutral mononuclear complexes [Mn(diclofenac)(2,2-bipyridine)(H2O)(2)] (diclofenac) (1) and [Mn(diclofenac)(2)(pyridine)(2)(H2O)(2)] (2), respectively. The structure of 1 was characterized by X-ray crystallography. In a preliminary attempt to evaluate the biological properties and possible application, the interaction of the complexes with calf-thymus DNA and human or bovine serum albumins was monitored. Additionally, the ability of the compounds to scavenge radicals such as 1,1-diphenyl-picrylhydrazyl, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and hydroxyl radicals was evaluated; the complexes were more potent scavengers than free sodium diclofenac.