Synthesis, Antimicrobial, Anticancer, and Molecular Docking Studies of Transition Metal Complexes of Thiadiazole‐Based Schiff Base

Abstract In the present work, four new metal complexes were synthesized using different metals such as Co(II), Ni(II), Cd(II), and Zr(IV), using Schiff base derived from 5‐bromosalicylaldehyde and 5‐amino‐1,3,4‐thiadiazole‐2‐thiol. The compounds were characterized using various analytical and spectroscopic techniques, including elemental analysis, molar conductance, magnetic moment measurements, mass spectral data, IR, 1 HNMR, and UV–vis spectra. The results confirmed the bidentate behavior of the ligand, leading to an octahedral geometry of the complexes. The antimicrobial potential of the synthesized compounds against three bacteria and three fungi was investigated by the disc‐diffusion method. The observed results demonstrate that the Ni(II) complex had the strongest antibacterial activity against B. subtilis and S. aureus , while the Co(II) complex had the highest antifungal activity against F. oxysporum and C. albicans . The DNA‐cleavage ability was explored using agarose gel electrophoresis. The anticancer activities of synthesized compounds were evaluated toward human neuroblastoma cell lines, i.e., SH‐SY‐5Y, where compound 3 exhibited the strongest anticancer activity against the cancer cell line. Additionally, density functional theory (DFT) calculations were performed to optimize the structures of the complexes. Furthermore, the molecular docking studies were conducted using AutoDock4 to explore the interaction mechanisms targeting both DNA and human serum albumin (HSA).