Copper(II) complexes based on 1,3,4-thiadiazolethiosemicarbazone NNS donor ligands: synthesis, molecular structure, DNA binding and <i>in silico</i> molecular docking approach
Fatmah Alkhatib, Thoraya A. Farghaly, Marwa F. Harras, Hoda A. El‐Ghamry
Abstract
Two derivatives of 1,3,4-thiadiazolethiosemicarbazone were used to synthesize Cu(II) complexes in 1:1 (M:L) molar ratio using chloride and acetate copper salts. The formulae of the obtained complexes were confirmed to be [L1CuCl(H2O)2]‧H2O, [L1Cu(OAc)(H2O)2]‧0.5H2O, [L2CuCl] and [L2Cu(OAc)(H2O)2]‧0.5CH3OH; where HL1 and HL2 are p-methylphenyl and p-nitrophenyl derivatives of 1,3,4-thiadiazolethiosemicarbazone. In the copper complexes, the two ligands act as monovalent anionic tridentate NNS donors. The geometries around the Cu(II) centers were concluded to be square planar and octahedral based on thermal analysis, electronic spectra and magnetic moment values. Evaluation of the binding mode of the ligands and their copper chelates with DNA; salmon sperm type (SS-DNA), were assessed applying UV-Vis spectral titration and viscosity measurements. The binding extent and binding mode of the organic ligands and their copper chelates with DNA was evaluated from calculation of the binding constant (kb) and compared with ethidium bromide. The binding energies of the obtained compounds with DNA were calculated by performing molecular docking studies in order to recognize the drug-DNA interactions ability. Molecular docking studies of the synthesized compounds were studied and revealed their intercalative binding potential into the DNA