Novel metal complexes containing 6-methylpyridine-2-carboxylic acid as potent α-glucosidase inhibitor: synthesis, crystal structures, DFT calculations, and molecular docking.

The World Health Organization (WHO) report shows that diabetes mellitus (DM) will be one of the ten deadly diseases in the near future. The best way to prevent DM is to decrease blood glucose levels and keep under control; therefore, it is important to design and synthesize the effective inhibitors that can be used in the treatment of DM disease. In this respect, a series of ten metal complexes containing 6-methylpyridine-2-carboxylic acid {[Cr(6-mpa)2(H2O)2]·H2O·NO3, (1), [Mn(6-mpa)2(H2O)2], (2), [Ni(6-mpa)2(H2O)2]·2H2O, (3), [Hg(6-mpa)2(H2O)], (4), [Cu(6-mpa)2(Py)], (5), [Cu(6-mpa)2(H2O)]·H2O, (6), [Zn(6-mpa)2(H2O)]·H2O, (7), [Fe(6-mpa)3], (8), [Cd(6-mpa)2(H2O)2]·2H2O, (9), and [Co(6-mpa)2(H2O)2]·2H2O, (10)} were synthesized as α-glucosidase inhibitors. We found that the IC50 values of the synthesized complexes ranged from 0.247 ± 0.10 to > 600 µM against α-glucosidase. The spectral analyses for these complexes characterized by XRD and LC-MS/MS were also carried out by FT-IR and UV-Vis spectra. Additionally, the DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level was applied to obtain optimal molecular geometries and spectral behaviors as well as significant contributions to the electronic transitions for the complexes. The molecular docking study was also performed to display interactions between the target protein (the template structure Saccharomyces cerevisiae isomaltase) and the synthesized complexes (1-10).

A novel series of mixed-ligand M(II) complexes containing 2,2'-bipyridyl as potent α-glucosidase inhibitor: synthesis, crystal structure, DFT calculations, and molecular docking.

Diabetes mellitus (DM) is a common degenerative disease and characterized by high blood glucose levels. Since the effective antidiabetic treatments attempt to decrease blood glucose levels, keeping glucose under control is very important. Recent studies have demonstrated that α-glucosidase inhibitor improves postprandial hyperglycemia and then reduces the risk of developing type 2 diabetes in patients. Therefore, the design and synthesis of high affinity glucosidase inhibitors are of great importance. In this regard, novel series of mixed-ligand M(II) complexes containing 2,2'-bipyridyl {[Hg(6-mpa)2(bpy)(OAc)]·2H2O, (1), [Co(6-mpa)2(bpy)2], (2), [Cu(6-mpa)(bpy)(NO3)]·3H2O, (3), [Mn(6-mpa)(bpy)(H2O)2], (4), [Ni(6-mpa)(bpy)(H2O)2]·H2O, (5), [Fe(6-mpa)(bpy)(H2O)2]·2H2O, (6), [Fe(3-mpa)(bpy)(H2O)2]·H2O, (7)} were synthesized as potential α-glucosidase inhibitors. Their effects on α-glucosidase activity were evaluated. All synthesized complexes displayed α-glucosidase inhibitory activity with IC50 values ranging from 0.184 ± 0.015 to > 600 µM. The experimental spectral analyses were carried out using FT-IR and UV-Vis spectroscopic techniques for these complexes characterized by XRD and LC-MS/MS. Moreover, the calculations at density functional theory approximation were used to obtain optimal molecular geometries, vibrational wavenumbers, electronic spectral behaviors, and major contributions to the electronic transitions for the complexes 1-7. Finally, to display interactions between the synthesized complexes and target protein (the template structure Saccharomyces cerevisiae isomaltase), the molecular docking study was carried out.

Copper(II) complex with 6-methylpyridine-2-carboxyclic acid: Experimental and computational study on the XRD, FT-IR and UV-Vis spectra, refractive index, band gap and NLO parameters.

Crystal structure of the synthesized copper(II) complex with 6-methylpyridine-2-carboxylic acid, [Cu(6-Mepic)2·H2O]·H2O, was determined by XRD, FT-IR and UV-Vis spectroscopic techniques. Furthermore, the geometry optimization, harmonic vibration frequencies for the Cu(II) complex were carried out by using Density Functional Theory calculations with HSEh1PBE/6-311G(d,p)/LanL2DZ level. Electronic absorption wavelengths were obtained by using TD-DFT/HSEh1PBE/6-311G(d,p)/LanL2DZ level with CPCM model and major contributions were determined via Swizard/Chemissian program. Additionally, the refractive index, linear optical (LO) and non-nonlinear optical (NLO) parameters of the Cu(II) complex were calculated at HSEh1PBE/6-311G(d,p) level. The experimental and computed small energy gap shows the charge transfer in the Cu(II) complex. Finally, the hyperconjugative interactions and intramolecular charge transfer (ICT) were studied by performing of natural bond orbital (NBO) analysis.