Synthesis, characterization, in-silico, and in-vitro biological studies of Cu(II), Zn(II) complexes of semicarbazone, thiosemicarbazone derivatives of dehydrozingerone

Abstract

Treatment of multidrug resistance pathogens has been a challenge for several decades. Herein, we report a novel Cu(II) and Zn(II) complexes of dehydrozingerone derivatives of semicarbazone and thiosemicarbazone. The semicarbazone and thiosemicarbazone derivative ligands were prepared by a modified method with better yield using aldol condensation. The prepared ligands and their metal complexes were characterized with spectroscopic methods (UV, IR, 1H-NMR, 13C-NMR, and DEPT-135), molar conductivity measurements, and thermogravimetric analysis (TGA). The compounds were assessed for antibacterial and antioxidant potential by following the disk diffusion and DPPH methods, respectively. The antimicrobial assay results show that ligands (L1 & L2) show lower to medium mean inhibition zones from 3.5 ± 0.00 -10.86 ± 0.82 mm at 100 µg/mL and 200 µg/mL. The complexes exhibited better antibacterial potential (7.44 ± 0.55 -15.44 ± 0.31 mm) as compared to ligands alone. Also, the complexes exhibited better percent antioxidant potential than both ligands. Furthermore, in silico docking data of compounds on Staphylococcus aureus gyrase confirms the prepared compounds are potential molecules with minimum interaction energy from – 7.6 to – 9.1 kcal/mol. The highest result was achieved by [Zn(L1)2(H2O)2] complex (– 9.1 kcal/mol). Therefore, the structural modification of dehydrozingerone to semicarbazone and thiosemicarbazone derivatives, and subsequent complexation with metals can enhance biological potentials.