Synthesis, Characterization, Molecular Docking, and In Vitro Biological Activities of Schiff Base Metal Complexes With Furan Moiety

Herein, Cu(II), Zn(II), and Cd(II) complexes with furan-derived Schiff base ligand, (E)-N¹,N¹-diethyl-N²-(furan-2-ylmethylene)ethane-1,2-diamine(DEF), were synthesized. The synthesized ligand and M(II) (M = Cu, Zn, and Cd) complexes were characterized to confirm their purity and successful synthesis using ¹H NMR, ¹³C NMR, and FTIR spectroscopy. Thermal analysis demonstrated their stability, whereas UV-Vis spectroscopy and molar conductance studies provided insights into their electronic properties and coordination behavior. Additionally, X-ray diffraction studies indicated that the Zn(II) and Cd(II) complexes have distorted tetrahedral geometries, whereas the Cu(II) complex adopted distorted square planar geometry. The studied complexes showed remarkable free-radical scavenging activity. Furthermore, they exhibited good inhibitory activity against urease and α-amylose. In particular, [Cu(DEF)Cl₂] showed the best antioxidant activity, with an IC₅₀ of 3.21 ± 0.19 μM, and the highest α-amylose inhibitory activities, with an IC₅₀ of 6.11 ± 0.33 μM. Moreover, [Cd(DEF)Br₂] proved to be more potent against Jack bean and Bacillus pasteurii ureases, with IC₅₀ values of 3.90 ± 0.11 μM and 6.01 ± 0.10 μM, respectively. Molecular docking studies showed a good correlation between the biological activities of the synthesized [M(DEF)X₂] complexes. Thus, the proposed compounds can serve as promising candidates for the treatment of infectious diseases.