Antioxidant capacity of binuclear Cu(II)‐cyclophanes, insights from two synthetic bioactive molecules

The compounds 2,9,25,32‐tetraoxo‐4,7,27,30‐tetrakis(carboxymethyl)‐1,4,7,10,24,27,30,33‐octaaza‐17,40‐dioxa[10.1.10.1]paracyclophane and 2,9,25,32‐tetraoxo‐4,7,27,30‐tetrakis(carboxymethyl)‐1,4,7,10,24,27,30,33‐octaaza[10.1.10.1]paracyclophane binuclear copper complexes (Cu 2 PO and Cu 2 PC, respectively) were studied by determining their antioxidant capacity using the TROLOX equivalent antioxidant capacity (TEAC) assay, and their cytotoxicity on cultured cells, as well as the superoxide dismutase (SOD)‐like activity. Cu 2 PO had an antioxidant capacity (0.1 g eq TROLOX mol −1 ) within the order of magnitude of ascorbic acid, and both, Cu 2 PO and Cu 2 PC were nontoxic to cultured peripheral mononuclear blood cells. The SOD‐like activity was evaluated using the nitroblue tetrazolium assay, and both compounds presented an excellent activity: for Cu 2 PO, the IC 50 was 52 nM and for Cu 2 PC an IC 50 of 0.5 μM was obtained comparable to CuZn SOD IC 50 17 nM (Fernandes et al., J Inorg Biochem 2007;101:849–858). These results suggest that synthetic binuclear macrocycles are good candidates to be used as synthetic bioactive molecules with applications in biomedicine. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:379–383, 2010; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.20350