Crystal structure, anti-Trypanosoma cruzi and cytotoxic activities of Cu(II) complexes bearing β-diketone and α-diimine ligands

Abstract

Three novel copper(II) complexes were synthesized: [Cu(tfa)2] (I), [Cu(tfa)(dmb)(NO3)].1.5H2O (II) and [Cu(tfa)(nphen)(NO3)] (III), where tfa = 4,4,4-trifluoro-1-(2-furyl)-1,3-butanedione, nphen = 5-nitro-1,10-phenanthroline and dmb = 4,4-dimethoxy-2,2-bipyridine. They were characterized by elemental analysis, conductivity measurements, FT-IR, UV–Vis and single-crystal X-ray diffraction. The X-ray crystal structures of I, II and III reveal that the β-diketone coordinates via the oxygen atoms, while the heterocyclic bases coordinate via their two nitrogen atoms. The cytotoxic activity of I, II and III was investigated in two tumor cell lines (Ehrlich tumor and sarcoma 180) and in a non-tumor cell line (myoblast C2C12). Complex III exhibited good activity (IC50 Ehrlich = 15.75 μM and IC50 sarcoma 180 = 16.90 μM) and selectivity (SI > 4) in both tumor cell lines. Subsequently, it was found that III also present good activity against Trypanosoma cruzi.