Synthesis and structural characterization of a zinc(II) complex of the mycobactericidal drug isoniazid - Toxicity against Artemia salina

A new zinc(II) complex of the mycobactericidal drug isoniazid (complex 1) was synthesized and characterized by XRD, vibrational spectroscopy (IR, Raman) and thermogravimetric analysis. The complex is constituted by two isoniazid (INH) molecules, six hydration water molecules and two perchlorate counter-ions for each metal center (C(12)H(26)N(6)Cl(2)O(16)Zn). Zinc(II) adopts a distorted octahedral geometry, where two INH molecules coordinate in a bidentate manner through the hydrazide group (N, O) and the other two isoniazid residues complete the coordination sphere of zinc(II) through their aromatic nitrogen atoms. This coordination pattern gives rise to a 2-D coordination polymer. Complex 1 belongs to the monoclinic system [a = 8.1190(2) angstrom, b = 17.977(4) angstrom. c = 9.1051(2) angstrom and beta = 100.87(3)degrees], space group P2(1). A biological assay with Artemia sauna was also performed. Complex 1 is almost 8.5 times more active than the free ligand. Its toxicity against A. sauna correlates well with the cytotoxic activity for some human solid tumors. Therefore, antitumoral properties could be expected from complex 1. (C) 2011 Elsevier Ltd. All rights reserved.