Synthesis, characterization and biological analysis of the complex [VO(Hdhp)2] (H2dhp = 2,3-dihydroxypyridine)

• Published in: Transition metal chemistry (Weinheim) 2008-04, Vol.33 (3), p.301-309
• Main Authors: Pepato, Maria T., Alberconi, Mayara F., da Rocha, Michelle C., Vendramini, Regina C., Brunetti, Iguatemy L., Batista, Alzir A., de Souza, Elizeu J., Garcia, Edgardo, Deflon, Victor M.
• Format: Article
• Language: English
• Subjects: Catalysis; Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Organometallic Chemistry; Physical Chemistry
• ISSN: 0340-4285; 1572-901X
• DOI: 10.1007/s11243-007-9003-5

A new vanadium (IV) complex with the monoanion of 2,3-dihydroxypyridine (H 2 dhp), or 3-hydroxy-2-(1H)-pyridone, was synthesized, characterized by physicochemical techniques and tested biologically. The EPR data for the [VO(Hdhp) 2 ] complex in DMF are: g x  = 1.9768, g y  = 1.9768 and g z  = 1.9390; A values (10 −4  cm −1 ): A x , 59.4; A y // , 59.4; A z , 171.0. The νV=O band in the IR spectrum of the complex is at 986 cm −1 . The complex is paramagnetic, with μ eff  = 1.65 BM (d 1 , spin-only) at 25 °C. The irreversible oxidation process [V(V)/V(IV)] of the [VO(Hdhp) 2 ] complex, as revealed in a cyclic voltammogram, occurs at 876 mV. The calculated molecular structure of [VO(Hdhp) 2 ] shows the vanadium(IV) center in a distorted square pyramidal environment, with the oxo ligand in the apical position and the oxygen donor atoms of the Hdhp ligands in the basal positions. The ability of [VO(Hdhp) 2 ] to mimic insulin, and its toxicity to hepato-biliary functions, were investigated in streptozotocin-induced diabetic rats and it was concluded that the length of treatment and the amount of [VO(Hdhp) 2 ] administered were effective in reducing experimental diabetes.