A novel series of M(II) complexes of 6-methylpyridine-2-carboxylic acid with 4(5)methylimidazole: Synthesis, crystal structures, alpha-glucosidase activity, density functional theory calculations and molecular docking

Novel complexes of 6-methylpyridine-2-carboxylic acid and 4(5)methylimidazole, namely [Mn(6-mpa)(2)(4(5)MeI)(2)] (1), [Zn(6-mpa)(2)(4(5)MeI)(2)] (2), [Cd(6-mpa)(2)(4(5)MeI)(2)] (3), [Co(6-mpa)(2)(4(5)MeI)(2)] (4), [Ni(6-mpa)(2)(4(5)MeI)(OAc)] (5) and [Cu(6-mpa)(2)(4(5)MeI)] (6), were synthesized for the first time. The structures of complexes 1-4 and complexes 5 and 6 were determined using X-ray diffraction and mass spectrometric techniques, respectively. The experimental spectral analyses for these complexes were performed using Fourier transform infrared and UV-visible techniques. The alpha-glucosidase inhibition activity values (IC50) of complexes 1-6 were identified in view of genistein reference compound. Moreover, the DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level was used to obtain optimal molecular geometry and vibrational wavenumbers for complexes 1-6. Electronic spectral behaviours and major contributions to the electronic transitions were investigated using TD-DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level with conductor-like polarizable continuum model and SWizard program. Finally, in order to investigate interactions between the synthesized complexes (1-6) and target protein (template structure S. cerevisiae isomaltase), a molecular docking study was carried out.