Synthesis, structure analysis, anti-bacterial and in vitro anti-cancer activity of new Schiff base and its copper complex derived from sulfamethoxazole

Abstract

A new bidentate Schiff base ligand (HL1), containing O,N donors was prepared by the reaction of sulfamethoxazole with 5-nitrosalicylaldehyde and characterized by elemental analysis, FT-IR, 1H and13C NMR. The copper complex of this ligand was synthesised by treating DMF-ethanolic mixture solution of the ligand of two equivalents with one equivalent of copper acetate. The complex was characterized on the basis of UV, FT-IR, molar conductance, EPR, magnetic moment and single crystal X-ray diffraction. Interestingly, the crystal structure of the octahedral complex showed two solvent molecules (DMF) as ligands at their axial positions. The molar conductance data revealed that the complex is a non-electrolyte. The Schiff base and its copper complex have been investigated as anti-bacterial and anti-fungal agents against various microorganisms. The in vitro cytotoxicity tests of the ligand and its copper complex were carried out in two different human tumour cell lines, HCT-116 and MDA – MB - 231. The cytotoxicity studies showed that the complex exhibited higher activity than cisplatin and carboplatin towards MDA – MB – 231. A new Schiff base (HL1) is formed by condensation of sulfamethoxazole and 5–nitro salicylaldehyde, which on reaction with copper acetate in DMF–ethanol mixture gives [Cu(L1)2(DMF)2] complex. Analytical, structural, spectral and molar conductivity measurements were used to investigate the chemical structure of the ligand and its complex. The synthesized complex was screened for in vitro anti-microbial and anti-cancer activity.