Synthesis, characterization and assessment of the cytotoxic activity of Cu(II), Fe(III) and Mn(III) complexes of camphoric acid-derived salen ligands.

Novel Cu(II), Fe(III) and Mn(III) salen-type metal complexes from (1 R,3 S)- N, N′-bis[salicylidene]-1,3-diamino-1,2,2-trimethylcyclopentane were synthesized and screened for their in vitro cytotoxic activity against three human cancer cell lines: melanoma, colorectal and breast. In vitro experiments carried out with the three metal complexes show that the copper complex exhibits the highest cytotoxic activity towards all cell lines studied, presenting IC50 values of 3.32-6.71 μM. A significant improvement in the anti-proliferative effect, by 20-fold, is observed with this complex when compared with conventional chemotherapy. The relationship between structure, redox characteristics and in human cancer cell lines was evaluated for the most efficient Cu(II) complex and associated with theoretical calculations. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]