Synthesis of some transition metal complexes containing 6-methylpyridine-2-carboxylic acid, structural analyses, investigation of effects on α-glucosidase enzyme

In the scope of this study, the novel mixed ligand metal complexes containing 6‒methylpyridine‒2‒carboxylic acid (6-mpaH) was synthesized for the first time, and the antidiabetic properties of the obtained complexes were investigated by determining the α‒glucosidase enzyme activity. As a result of the synthesis studies, 10 of 28 new complex structures with mixed ligand were obtained as single crystal structure. Besides, Co metal complex containing the 3‒methylpyridine‒2‒carboxylic acid (3-mpaH) and Cr, Mn, Hg, Zn and Fe metal complexes of the 6-mpa were synthesized for the first time. Within the scope of this study, 17 of 37 complex structures obtained as single crystal were characterized by X‒ray diffraction method and the structures of remaining complexes obtained as powder structures were determined by mass spectroscopy. The structural, vibrational and electronic properties of these complexes were investigated in detail by using both the experimental and hybrid DFT/HSEh1PBE level. According to the results of α‒glucosidase enzyme activity, it was concluded that the best inhibitory structures between synthesized complexes were Hg metal‒containing complexes regardless of ligand. Activity results in all complex structures containing Cu (9, 17, 20, 29) were observed in 4(5)MeI>NCS>dipya>bpy by decreasing inhibition values depending on the ligands. It is determined that this change was not the same for the other metals used. According to the results, the in vitro results of the metal complexes containing Hg, Cu and Fe were found to be significant when the structure activity relationships of different metal‒containing ligands were compared.