Copper(II) monohelix complexes with pyrazine-modulated long-chain oligo-α-aminopyridine ligand: synthesis, crystal structures, and bioactivity studies

Ismayilova S. Z., Ismayilov R. H., Tagiyev D. B., ŞENOL H., Medjidov A. A., Huseynova M. T., ...Daha Fazla

Journal of Molecular Structure, cilt.1347, 2025 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1347
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.molstruc.2025.143295
  • Dergi Adı: Journal of Molecular Structure
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Anahtar Kelimeler: Copper complex, Enzyme inhibition, Hydrogen bonds, Modulated oligo-α-aminopyridine ligand, Supramolecular networks
  • Marmara Üniversitesi Adresli: Evet

Özet

Using the pyrazine-modulated pentapyridyltetraamine ligand N2,N2′-(pyridine-2,6-diyl)bis(N6-(pyrazin-2-yl)pyridine-2,6-diamine) H4N9-2pz, three new mononuclear complexes [Cu(H4N9-2pz)](NO3)2∙(CH3CN) 1, [Cu(H4N9-2pz)]Cl2∙2(H2O) 2 and [Cu(H3N9-2pz)] (CH3COO)∙2.5(H2O) 3 have been synthesized, structurally characterized, and their bioactivity properties studied. In vitro analysis of complexes 1-3 revealed that they inhibited AChE and BChE more effectively than the widely available inhibitor tacrine (IC50: 123.58 ± 6.80 and 146.18 ± 7.91 µM). Additionally, their IC50 values for AChE and BChE ranged from 32.87 to 68.15 and 14.60 to 31.68 µM, respectively. The g|| and g┴ components of the g factor have similar values in the EPR spectrum of complexes 1-3 (g|| = 2.0179 and g┴ = 2.1246 for 1; g|| = 2.0044 and g┴ = 2.1425 for 2; g|| = 2.0118 and g┴ = 2.1356 for 3). The single crystal X-ray approach revealed a distorted trigonal bipyramidal geometry of the complexes, which is consistent with the "inverted type" of EPR spectra (g┴ > g||∼ ge), measured magnetic moment susceptibility, and electronic spectrum studies. The comparable structures of complexes 1–3 suggest that the H4N9-2pz ligand, rather than the nitrate, carboxylate, or chloride counterions, is critical for complex formation.