The complex of zinc with N-(5,6-dihydro-4H-1,3-thiazine-2-yl)benzamide

A complex of zinc with N-(5,6-dihydro-4H-1,3-thiazin-2-yl)benzamide (L) ligand, LZnCl₂, was synthesized for subsequent medical trials. The molar extinction coefficients were determined for LHBr solutions in water and physiological saline, and for LZnCl₂ ethanol solution. The ligand stability in various solvents was evaluated and the value of its protonation constant was found for the physiological saline solution, logK = 5.3±0.2. The impossibility of determination of the complex stability constant by the potentiometric titration method was demonstrated. The complex exhibited an insufficient stability in aqueous and physiological saline solutions, but was stable as the solution in alcohol. There was no sorption observed upon the treatment of ligand with hydroxyapatite nanoparticles, which could be a potential carrier for the therapeutic form of LZnCl₂, providing additional degrees of freedom for the interaction of ligand with cell membranes and a prolonged action of zinc ions.