Potential antidiabetic drugs of metformin with insulin-enhancing anions [VO2(dipic)]− and [VO2(dipic-OH)]−: Synthesis, characterization and X-ray crystal structure

• Published in: Polyhedron 2015-12, Vol.102, p.239-245
• Main Authors: Ghasemi, Khaled, Ghasemi, Fatemeh, Rezvani, Ali Reza, Graiff, Claudia, Notash, Behrouz
• Format: Article
• Language: English
• Subjects: 4-Hydroxypyridine-2,6-dicarboxylic acid; Crystal structure; Insulin-enhancing anions; Metformin; Vanadium complex
• ISSN: 0277-5387
• DOI: 10.1016/j.poly.2015.09.053

The synthesis and characterization of vanadium anionic complexes of a dipicolinic ligand with metformin as counter ion are described. These complexes can be interesting for biochemists in the potential, associative or synergistic antidiabetic effect because of the coexistence of metformin and insulin-enhancing anions [VO2(dipic)]− and [VO2(dipic-OH)]− as well as their solubility in water. [Display omitted] Two new complexes of antidiabetic drug metformin, [HMet][VO2(dipic)]·H2O (1) and [HMet][VO2(dipic-OH)]·H2O (2), where H2dipic=2,6-pyridinedicarboxylic acid, H2dipic-OH=4-hydroxy-2,6-pyridine dicarboxylic acid and Met=metformin, were synthesized. These complexes were characterized by elemental analysis, 1H and 13C NMR, FTIR, and UV–Vis spectroscopies. Solid-state structures of [HMet][VO2(dipic)]·H2O (monoclinic, P21/n) and [HMet][VO2(dipic-OH)]·H2O (monoclinic, P21/c) were determined by means of single crystal X-ray diffraction analysis. In these complexes, metformin is monoprotonated and acted as counter ion. These compounds are soluble in water and hydrogen bond interactions stabilize their crystal structures.