Abstract
Five novel nanometric homo-binuclear complexes have been synthesized by the reaction of Cu(II), Co(II), Ni(II), Mn(II) and Zn(II) salts with a new azo dye 4-(2,4-dihydroxy-phenylazo)-
N
-thiazol-2-yl-benzenesulfonamide (H
2
L) with the aim to develop neoteric antitumor drugs. H
2
L has been prepared by coupling of sulfathiazole with resorcinol in order to comprise the bioactivities of sulfonamide part and azo group in the formed metal complexes which greatly enhance their bio-efficiencies. The ligand and complexes have been fully characterized using various spectral and analytical techniques. The obtained data indicated a dibasic tetradentate nature of ligand which coordinated via deprotonated phenolic oxygen, one azo group nitrogen, N-atom of thiazole ring, and sulfonamide oxygen forming tetrahedral geometry around the central metal ions. XRD data confirmed the crystalline nature of ligand and amorphous nature of the complexes. TEM images proved nanometeric size of complexes particles. The data of antimicrobial screening revealed that metal complexes are more potent than the azo dye ligand against varies micro-organisms. Anticancer activities of all compounds were evaluated against human liver carcinoma cells (HepG-2) and breast carcinoma cells (MCF-7). Cu(II) complex showed the highest anticancer activity (IC
50
= 23.6 µg/ml) against HepG-2 cells. Co(II) complex displayed the greatest anticancer activity (IC
50
of 7.67 µg/ml) contra MCF-7 cells. Electronic absorption and viscosity studies proved that H
2
L and complexes interact with DNA by intercalation binding and electrostatic force groove binding modes, respectively. The results of this study ascertain that Cu(II) and Co(II) complexes are very favorable candidates for further applications in cancer therapy.