Fe(II), Cu(II), Ni(II) and Co(II) metal complexes of sulfonamide ligand derived from sulfadiazine: synthesis, characterization, cytotoxic activity and DNA/BSA binding properties

A novel sulfonamide ligand (HL) has been synthesized by reacting 4-benzoyl-5-phenyl-2,3-furandione with sulfadiazine, a pyrimidine ring and sulfonamide derivative. The ligand was analyzed using elemental analysis, mass spectrometry (LC-MS/MS), FT-IR, NMR, and UV-Vis spectroscopy. Furthermore, the sulfonamide ligand 2-benzoyl-3-hydroxy-3-phenyl-N-(4-(N-(pyrimidin-2-yl)sulfamoyl)phenyl)acrylamide (HL) and its metal complexes with Cu(II), Fe(II), Co(II) and Ni(II) chlorine salts have been formed, and their structures were characterized. The metal complexes were studied by elemental analysis, IR, LC-MS/MS, UV-Vis, magnetic moment, and molar conductivity. Based on the magnetic moment data, it can be concluded that all complex compounds exhibit octahedral geometry. Additionally, the molar conductivity values (ranging from 1.92 to 3.62 µS/cm) indicate that the complexes do not possess any molar conductivity. The synthesized metal complexes were found to exhibit strong binding to FSdsDNA in UV-visible absorption titration and ethidium bromide (EB) displacement experiments. In comparison with the EB viscosity curve, the tested compounds showed a minor groove binding mode in their interaction with FSdsDNA. A ligand and its new metal complexes were tested in colon (DLD-1) and lung (A549) cancer cell lines for a 48 h incubation period. The results demonstrated that compounds except L-Fe had cytotoxic effects against both cancer cell types. Particularly, complex L-Cu demonstrated very high cytotoxic effects with IC₅₀ values of 50.65 and 22.84 µM in DLD-1 and A549, respectively.