Novel series of nanosized mono- and homobi-nuclear metal complexes of sulfathiazole azo dye ligand: Synthesis, characterization, DNA-binding affinity, and anticancer activity

Novel five nanosized mono- and homobi-nuclear complexes of 4-(2,4-dihydroxy-5-formylphen-1-ylazo)-N-thiazol-2-yl-benzenesulfonamide (H2L) ligand were synthesized for developing new anticancer agents. H2L was prepared by coupling the diazonium salt of 2-(p-aminobenzenesulfonamido)thiazole with 2,4-dihydroxybenzaldehyde in order to integrate the bio-effectiveness of both azo group and sulfonamide part in the synthesized metal chelates which strongly increase their bio-activities. H2L and synthesized Cu, Co, Ni, Mn and Zn complexes were characterized applying different analytical and spectral methods. The obtained results revealed that H2L coordinated with divalent metal ions of copper, cobalt and nickel in a monobasic bidentate mode through the azo group nitrogen, and deprotonated phenolic oxygen whereas H2L coordinates with Mn(II), and Zn (II) in dibasic tetradentate mode via the azo group nitrogen, deprotonated phenolic oxygen, sulfonamide oxygen, and N-atom of thiazole ring. All metal complexes had a tetrahedral geometry around the metal centers. XRD patterns denoted the ligand crystalline and the complexes amorphous natures. TEM images proved the nanosized range of all complex's particles. UV-Vis spectra and viscosity techniques revealed that H2L and complexes exhibited groove binding mode interactions with DNA. Anticancer efficiency of the ligand and complexes were examined against breast carcinoma cells (MCF-7) and human liver carcinoma cells (HepG-2). Co(II) and Zn(II) complexes displayed the greatest anticancer activity and are very promising candidates for future applications in cancer therapy.