Inhibition behavior on alkaline phosphatase activity, antibacterial and antioxidant activities of ternary methimazole-phenanthroline-copper(II) complex

NORA M. URQUIZA; M. SOLEDAD ISLAS; MARÍA LAURA DITTLER; MARÍA A. MOYANO; SILVIA G. MANCA; LUIS LEZAMA; TEÓFILO ROJO; JUAN J. MARTÍNEZ MEDINA; MAXIMILIANO DIEZ; LEONOR LÓPEZ TÉVEZ; PATRICIA A.M. WILLIAMS; EVELINA G. FERRER

INORGANICA CHIMICA ACTA

ELSEVIER SCIENCE SA

Lugar: Amsterdam ; Año: 2013 vol. 405 p. 243 - 251

0020-1693

Methimazole (MetimzH), is a sulfur containing ligand which is an antithyroid drug commonly used to treat Graves´ disease acting as an inhibitor of the enzyme thyroid peroxidase. A new ternary Cu(MeimzH)2(phen)(H2O)2]Cl2 (Cu-Met) complex of this drug containing also phenanthroline as a second ligand (phen) was synthesized and characterized by elemental analysis, dissolution behavior, thermogravimetric analysis, UV-vis, diffuse reflectance, FTIR and EPR spectroscopies. As it is previously reported, the binary [Cu(MeimzH)2(H2O)2](NO3)2.H2O (Cu-Met) complex can act as an inhibitor of alkaline phosphatase (ALP). In this work, the inhibitory effect of methimazole, phenanthroline, [Cu(phen)2Cl]Cl (Cu-phen) and the new ternary complex has also been investigated and compared with Cu-Met together with in vitro test of susceptibility against E. coli, P. aeruginosa, S. aureus, S. epidermidis and E. faecalis bacteria. To our knowledge, the antibacterial activity of methimazole, is determined for the first time. For the ternary complex, results show that coordination increased the antibacterial effect especially against E. faecalis demonstrating a strong effect against S. aureus and S. epidermidis. The antibacterial assays also indicate that in same strains the new complex show better activity than their ligands. ALP inhibition ability was lower than the binary complex (Cu-Met) probably due to the absence of labile ligands around the metal center. Moreover, the antioxidant activity determinations show that for the copper complexes the effect decreases as follow: Cu-Met> Cu-Phen> Cu-Met-Phen.