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

Abstract

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 mV=O band in the IR spectrum of the complex is at 986 cm -1 . The complex is paramagnetic, with l 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.

3D coordination polymers with vanadyl fragments and alkaline earth metal ions

“…Many of these compounds serve as models of biological systems that are present in the organism or have biological activity (biological clusters, metalloporphyrins, heterovalent and heteronuclear com pounds). 1- 3 Numerous examples of oxovanadium(IV) coordination compounds exhibiting high catalytic activity were reported. 4-7 In addition, due to the presence of one unpaired electron on the metal center in VO 2+ complexes (S = 1/2), these compounds are convenient magnetic blocks for the synthesis of magnetically active complex structures, as well as for investigation of the nature of spin spin exchange interactions.…”