Title : Explorative study of Schiff base and its Co2+, Mn2+ and Fe3+ complexes: Synthesis, characterization, antimicrobial, anticancer, DNA cleavage activities and DFT calculations
Abstract:
This study reports the synthesis, characterization, and biological investigation of Schiff base ligand 2-decanone thiosemicarbazone, and its complexes with Co(II), Mn(II), and Fe(III) ions. The structures of the compounds were confirmed using Fourier-transform infrared spectroscopy (FTIR), proton and carbon-13 nuclear magnetic resonance (1H and 13C NMR), mass spectrometry, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and elemental analysis. Biological activities were investigated through antimicrobial assays against S. aureus, E. coli, A. fumigatus, and C. albicans, DNA cleavage studies, and cytotoxic tests on human cancer cell lines, including K562 (leukaemia), HeLa (cervical), MCF-7 (breast), HT-29 (colon), and HOP-62 (lung). The complexes displayed stronger antimicrobial activity than the free ligand; notably, the Co(II) complex produced a 24mm inhibition zone against S. aureus, and the Fe(III) complex showed highest antifungal effect with a 40mm zone of inhibition against A. fumigatus. DNA cleavage experiments indicated efficient interaction with microbial DNA. Anticancer evaluation revealed broad cytotoxic activity, with the Fe(III) complex most effective against K562 leukaemia cells, and Co(II) and Mn(II) demonstrating significant effects against HeLa and MCF-7 cells. Density Functional Theory (DFT) computations were performed to analyse the electronic structure, stability, and reactivity profiles of the complexes. These comprehensive findings suggest that the synthesized Schiff base metal complexes are promising candidates for antimicrobial and anticancer drug development.
