Synthesis and structural characterization of Cu(II)/Pd(II) complexes derived from FDA-approved sulfonamide Schiff bases: In vitro and in silico evaluation of CA II inhibition and antibacterial activity

Alyar S., ÖZDEMİR ÖZMEN Ü., Adem Ş., Öztürk A., Gündüzalp A. B., Alyar H.

Journal of Molecular Structure, cilt.1369, 2026 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1369
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1016/j.molstruc.2026.146405
  • Dergi Adı: Journal of Molecular Structure
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Anahtar Kelimeler: Anti-bacterial activity, CA II, DFT, Molecular docking, Sulfa drugs
  • Gazi Üniversitesi Adresli: Evet

Özet

In this study, Cu(II) and Pd(II) complexes were synthesized using previously prepared FDA-approved sulfonamide Schiff base ligands (S1M–S3 and S2M–S3), and their structures were characterized by elemental analysis, FT-IR, LC-MS, and TGA, along with magnetic susceptibility and molar conductivity measurements. The ligands were optimized at the DFT/B3LYP (6-311++G(d,p)) level, whereas the synthesized complexes were optimized at the DFT/B3LYP/LANL2DZ level. CA II inhibitory assays showed that the Cu(S2M–S3)₂ complex exhibited strong inhibitory potential with an IC₅₀ value of 0.73 μM, while the S1M–S3 ligand showed moderate inhibition and the S2M–S3 ligand was inactive at the tested concentrations. Regarding antibacterial activity, S1M–S3 and Pd(S1M–S3)₂ demonstrated superior performance, particularly against Gram-positive bacteria, compared to reference antibiotics. Based on the CA II inhibitory and antibacterial results, the possible interaction mechanisms of all compounds were investigated through molecular docking studies. The relationships between the calculated parameters and biological activities were evaluated. These findings highlight both the impact of metal coordination on biological activities and the pharmacological potential of the Schiff base ligands.