Synthesis, characterization, and biological activity of oxovanadium(IV) complexes with polyalcohols

Oxovanadium(IV) complexes of carbohydrates: A brief overview

“…Using one of the general synthetic procedures described above, i.e. interaction of the polyols with VOCl 2 in aqueous solutions at pH 12 and precipitation of the complexes by addition of absolute ethanol, complex species of composition Na 2 [VO(polyol) 2 ]ÁH 2 O were obtained in all cases in the form of green microcrystalline powders [30]. The IR spectra confirm that metal/ligand interaction occurs by pairs of deprotonated ligand OH-groups.…”

Impact of Vanadium Complexes Treatment on the Oxidative Stress Factors in Wistar Rats Plasma

“…Vanadate does inhibit the transport of iron-siderophore complexes [9], showing that there is an interaction of vanadium with iron transport systems. Many natural metabolites, including glutathione, cysteine, ascorbic acid, nucleotides, and carbohydrates, form complexes with vanadium that have been characterized by the different authors in [10–12]. The interactions of vanadium and antioxidant like reduced glutathione or superoxide dismutase, a particularly well-defined system, could be intimately involved in the interactions of cellular vanadium and redox properties [13].…”

Two galactomannan preparations from seeds from Mimosa scabrella (bracatinga): Complexation with oxovanadium(IV/V) and cytotoxicity on HeLa cells

“…The main regions Table 1 Binding constants of GALMAN (A, B) (L) with VO 2+ /VO 3+ (M). where modifications in absorption due to complexation were expected are near to 1370-1380 cm À1 , which is due to C-C-O and C-O-H deformations [66], where there was a major displacement for the complexed and non-complexed galactomannan. These differences can be explained due to complexation of VO 2+ /VO 3+ ions through oxygen atoms, modifying the angles of the C-C-O-H of the non-complexing and the C-C-O atoms involved in the complexation.…”

“…Although no great displacements in the wave numbers were observed, the shape of the three absorptions at approximately 1025, 1079 and 1150 cm À1 of the biopolymers alone and the spectra of the complexes with oxovanadium ions, were completely different, also confirming that the secondary carbon -OH groups were also involved in formation of complexes. This set of alcohol absorptions are combined into broad bands, different from those of simple alcohols in spectra of carbohydrates, with no aldehyde carbonyl absorption, due to their cyclic hemiacetal structure [66,67]. It is significant that the lack of absorptions found in the spectra at approximately 1730 cm À1 showed that oxidation of the galactomannans did not occur during the complexation process [68].…”

“…Barrio et al [37] confirmed these effects in GluVO complexes, however, complexes of vanadyl with other monosaccharides caused stimulation of URM106 proliferation. Complexes of oxovanadium(IV) with linear polyalcohols inhibited cell proliferation in tumour osteoblasts [66]. The different and frequently opposing effects of organic and inorganic vanadium compounds are dependent on factors such as cell type, concentration, and in the case of organic complexes, of the ligand bound to the metal [19].…”