RESUMO
The coordination behavior of copper(II) with tricarballylic acid (H(3)TCA) and imidazole (Imz) is described. Speciation in aqueous solution has been determined at 25 degrees C and 0.15M NaCl ionic strength by potentiometric measurements and EPR characterization of the species. Two new compounds CuTCAH.3H(2)O and CuTCAHImz.2H(2)O were obtained and characterized by elemental analysis diffuse reflectance, FTIR (Fourier transform infrared spectroscopy), EPR and thermal behavior. Their in vitro superoxide dismutase-mimetic activities have been tested.
Assuntos
Cobre/química , Imidazóis/química , Compostos Organometálicos/química , Superóxido Dismutase/química , Ácidos Tricarboxílicos/química , Compostos Organometálicos/síntese química , Superóxido Dismutase/síntese químicaRESUMO
The synthesis, characterization and comparative biological study of a series of antibacterial copper complexes with heterocyclic sulfonamides were reported. Two kinds of complexes were obtained with the stoichiometries [Cu(L)2] . H2O and [Cu(L)2(H2O)4] . nH2O. They were characterized by infrared and electronic spectroscopies and the crystal structure of [Cu(sulfisoxazole)2(H2O)4] . 2H2O was determined by single crystal X-ray diffraction. It crystallized in the C2/c with Z = 8 monoclinic space group C2/c with Z = 8. The Cu(II) is in a slightly tetragonal distorted octahedron formed by four oxygen atoms from water molecules and two nitrogen atoms from two isoxazole rings. The antimicrobial activity was evaluated for all the synthesized complexes and ligands using the agar dilution test. The results showed that the complexes with five-membered heterocyclic rings were more active than the free sulfonamides while the pyrimidine, pyridine and pyridazine complexes had similar or less activity than the free ligands. In order to find an explanation for this behavior lipophilicity and superoxide dismutase-like activity were tested, showing that the [Cu(sulfamethoxazol)2(H2O)4] . 3H2O presented the highest antimicrobial potency and a superoxide dismutase-like activity comparable with pharmacological active compounds.