Design and synthesis of amino sugar-based Schiff base Zn(II) and Cu(II) complexes: structural elucidation, DFT studies, antimicrobial evaluation, and in silico ADMET profiling

Schiff-bases derived from amino sugar represent good candidates for use as ligands owing to their biocompatibility, structural diversity, and superior metal chelating property. In the current work, new ligands (Schiff-base) were prepared by condensing amino sugar derivatives with aromatic aldehydes, followed by metal complexation with Zn(II) and Cu(II) metal ions under optimized conditions. The newly synthesized ligands and their zinc and copper complexes were analyzed using FTIR, UV-visible, NMR, XRPD, and FESEM-EDX methods. Spectroscopic evidence obtained from FTIR and UV-visible studies confirmed the involvement of the azomethine nitrogen in coordination with the metal ion. Based on XRD and FESEM-EDX findings, the data clearly demonstrate that the complexes have crystalline structure, chemical composition, and unique surface morphology. Structural and DFT studies suggested distorted tetrahedral geometries around the metal centers. Biological evaluation showed that the metal complexes exhibited enhanced antibacterial activity compared with the free ligands. ADMET analysis indicated favorable drug-like properties, supporting metal complexation as an effective approach for improving the biological potential of amino sugar-derived Schiff bases. Overall, the findings highlight the potential of metal complexation as an effective strategy for enhancing the biological and pharmacokinetic properties of amino sugar-derived Schiff base compounds.