Green synthesis and characterization of new carbothioamide complexes; cyclic voltammetry and DNA/methyl green assay supported by silico ways versus DNA-polymerase

Three novel complexes with the formulae of [Ni(L)2(H2O)2], [Zn(HL)2(OAc)2] and [UO2(L)2].2H2O were synthesized from simple thiosemicarbazide derivative. The ligand in such bis-form binds either as mononegative bidentate or neutral bindentate mode. The NS donors were the binding centers towards all central atoms inside an octahedral geometry. This geometry was supported by 3A2g?3T1g(P,t3) and 3A2g?3T1g(F,t2) transitions that assigned from the bands in UV-Vis spectrum of Ni(II) complex. All structures were optimized under DFT method by using B3LYP/6-31G (d) basis set to estimate valuable quantum data. The charges of N11 (-0.197790) and S14 (-0.067486) donors describe their sufficient nucleophilicity for coordination. Cyclic voltam-mograms of Ni+2 were studied in presence of the ligand to measure the shift in redox peak that affected by the Ni2+-ligand covalency. The elevated stability constants (bML) and Gibbs free ener-gies (DG) suggest the successive building to stable complex in solution. The antimicrobial screening showed an excellent inhibition role from the ligand towards the tested bacteria. Moreover, the geno-toxicity of the new compounds was assessed using DNA/ methyl green assay. The ligand exhibited the best decay for the green color results from DNA/ methyl green solution. This in vitro investiga-tion was strengthened by silico ways among that the interaction with DNA-polymerase proteins (1bpy, 5szt and 1zqa). A drug with code number MolPort-002-822-252 has high similarity to our ligand in its binding with DNA beside a low Root Mean Square Deviation value (RMSD = 0.266). Further, the ligand interacted perfectly to DG 6(T) residue in 1bpy protein via H-donor bond and the scoring energy value of the docking pose was excellent (S =-6.1512 kcal/mol). The BOILED -Egg indicates the ability of the ligand to absorb in brain barrier. While, there is no ability for such compound to absorb in gastrointestinal tract. Additionally, the ligand doesn't play as a substrate of P-gp protein, which is considered favorable for protecting tissues and organisms.(c) 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Three novel complexes were synthesized from a thiosemicarbazide derivative and characterized by their chemical structures and properties. The complexes exhibited strong binding to central atoms in an octahedral geometry with the ligand acting as mononegative bidentate or neutral bidentate. The complexes showed high stability and inhibition against bacteria, as well as good interaction with DNA-polymerase proteins.