Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Vanadium Compounds”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
PubMed2005

Effect of bis[curcumino]oxovanadium complex on non-diabetic and streptozotocin-induced diabetic rats.

The effect of the vanadium complex bis[curcumino]oxovanadium (BCOV) on blood glucose level, serum lipid levels, blood pressure and vascular reactivity were studied in non-diabetic and streptozotocin-induced diabetic (STZ-diabetic) rats and compared to that of vanadyl sulfate. Blood glucose level, serum lipid levels, and blood pressure were significantly increased in STZ-diabetic rats. Vascular reactivity to various agonists such as noradrenaline and acetylcholine were significantly increased in STZ-diabetic rats. Blood glucose and serum lipid levels were restored to normal in STZ-diabetic animals treated with vanadyl sulfate at a concentration of 0.5 mmol/kg/day (p.o.). However, vanadyl sulfate at a concentration of 0.2 mmol/kg/day (p.o.) did not produce any significant change in blood glucose and lipid levels. There was no significant effect of vanadyl sulfate (0.2 or 0.5 mmol/kg/day) treatment on blood pressure and vascular reactivity in STZ-diabetic rats. Vanadyl sulfate significantly reduced the body weight of non-diabetic and STZ-diabetic rats. Moreover, it also caused severe diarrhea in both groups of animals. Treatment with BCOV (0.05, 0.1 and 0.2mmol/kg/day, p.o.) significantly decreased blood glucose level and serum lipids in STZ-diabetic rats. Furthermore, administration of BCOV to STZ-diabetic rats restored the blood pressure and vascular reactivity to agonists to normal. There was no significant change in the body weight of BCOV treated non-diabetic and STZ-diabetic rats. Diarrhea was not observed in both BCOV treated groups. In conclusion, the present study shows that the vanadium complex BCOV has antidiabetic and hypolipedimic effects. In addition, it improves the cardiovascular complications associated with diabetes.

Animals↗
PubMed2005

Amelioration of diabetic dyslipidemia by macrocyclic binuclear oxovanadium complex on streptozotocin induced diabetic rats.

Diabetic dyslipidemia, the main causative factor for the progression of vascular complications in diabetes, is caused due to hyperglycemia and excess mobilisation of fatty acids. Recently we have reported on a novel macrocyclic binuclear oxovanadium (MBOV) complex synthesized by us with significant hypoglycemic efficacy and without any apparent toxicity on streptozotocin induced diabetic rats. In the present study, streptozotocin induced diabetic rats were treated with the vanadium complex (5 mg/kg body weight/day) for a period of 30 days and at the end of the treatment period the status of the lipid profile in the plasma, liver and kidney was evaluated. Also the fatty acid composition of liver and kidney were analysed by gas chromatography. The increased levels of lipid contents in plasma and tissues observed in diabetic rats were reverted back to near normal levels by the administration of the vanadium complex. Also the decreased levels of HDL cholesterol and increased levels of LDL cholesterol in plasma of diabetic rats were restored to near normal levels by the treatment with the vanadium complex. The altered fatty acid composition in liver and kidney were restored by the treatment. The results enhance the claim for the macrocyclic binuclear oxovanadium complex as a potent anti-diabetogenic drug.

Animals↗
PubMed2000

Biochemical and morphological alterations in rat liver Golgi complexes after treatment with bis(maltolato)oxovanadium(IV) [BMOV] or maltol alone.

Oral treatment with maltol or bis(maltolato)oxovanadium(IV) [BMOV] alters the biochemical activity of the rat liver Golgi marker enzyme, i.e., galactosyltransferase (GalT), and the organelle morphology in a relatively short time. Four groups of rats were investigated: control (C), treated with BMOV for 2 days (pVC), treated with BMOV for 7 days (C+V), and treated with maltol alone for 7 days (C+M). All drugs were administered as drinking solutions. These conditions were used, because normalization of galactosyltransferase activity (GalT) and morphology of rat liver Golgi complexes were previously found by us in streptozotocin-induced diabetes. In this paper, we present the influence of BMOV or maltol alone (as a vanadium ligand in BMOV compound) on rat liver Golgi complexes. The lowest statistically significant enzyme activity, in comparison with three other groups of rats (p < 0.01), was found in rats treated with BMOV solution for two days (pVC). Liver Golgi complexes in these rats showed relatively slight changes as compared with controls. The activity of GalT was similar to controls of the C+V and C+M groups. Morphological examinations of the Golgi apparatus in rats treated with vanadium salts revealed a slightly increased secretory activity. In response to various agents used in experiments, the Golgi complexes were generally reduced in size, except for the (C+M) group. Not only cisternae, but also vacuoles and associated vesicles on both sides of stacks were reduced in almost all Golgi structures. Ultrastructural findings were generally in agreement (except for pVC group) with biochemical results (yields of liver Golgi-rich fractions, activity of galactosyltransferase) obtained in the same rats.

Administration, Oral↗
PubMed1992

Interaction of porcine uterine fluid purple acid phosphatase with vanadate and vanadyl cation.

Uteroferrin, the purple acid phosphatase from porcine uterine fluid, is noncompetitively inhibited by vanadate in a time-dependent manner under both aerobic and anaerobic conditions. This time-dependent inhibition is observed only with the diiron enzyme and is absent when the FeZn enzyme is used. The observations are attributed to the sequential formation of two uteroferrin-vanadium complexes. The first complex forms rapidly and reversibly, while the second complex forms slowly and results in the production of catalytically inactive oxidized uteroferrin and V(IV), which is observed by EPR. The redox reaction can be reversed by treatment of the oxidized enzyme first with (V(IV)) and then EDTA to generate a catalytically active uteroferrin. Multiple inhibition kinetics suggests that vanadate is mutually exclusive with molybdate, tungstate, and vanadyl cation. The binding site for each of these anions is distinct from the site to which the competitive inhibitors phosphate and arsenate bind. The time-dependent inhibition by vanadate of uteroferrin containing the diiron core represents a new type of mechanism by which vanadium can interact with proteins and gives additional insight into the binding of anions to uteroferrin.

Acid Phosphatase↗
PubMed2005

Characterization of novel vanadium(III)/acetate clusters formed in aqueous solution.

We report the first structures of simple acetate complexes of vanadium(III) formed in aqueous solution. Paramagnetic (1)H NMR spectroscopy titration experiments indicate the formation of two major V(III)/acetate complexes in acidic aqueous solution for acetate/V(III) < or =4, pD 3.50. A novel tetranuclear cluster and a trinuclear cluster have been characterized by X-ray diffraction studies. Mass spectrometry measurements show these clusters retain their integrity in solution.

Acetates↗
PubMed1986

Vanadium metabolism in wild type and respiratory-deficient strains of S. cerevisiae.

Vanadium metabolism was studied in a wild type and respiratory-deficient strain of S. cerevisiae. Inhibition of growth by vanadate [V(+5)], vanadate accumulation, and conversion of medium vanadate [V(+5)] to both cell-associated and medium vanadyl [V(+4)] and vanadate [V(+5)] were compared. The growth of both the parental and respiratory-deficient strains was inhibited by vanadate at concentrations greater than or equal to 1 mM. Both parental and respiratory-deficient strains accumulated vanadate and converted medium vanadate to cellular vanadyl as detected using electron spin resonance (ESR). The accumulation of cell-associated vanadyl was correlated with the loss of medium vanadate in both strains using a chemical assay. In contrast, the respiratory-deficient strain showed a greater amount of a cell-associated vanadate compound, as detected with vanadium-51 nuclear magnetic resonance (51V-NMR), than the wild type strain or a representative respiratory-competent vanadate-resistant mutant. These data imply that mitochondrial function may be directly involved in vanadium metabolism.

Cell Division↗
PubMed2006

Polynuclear vanadium complexes from thermal decomposition of [V3O(O2CPh)6(H2O)3]Cl.

Solid-state decomposition of [V3O(O2CPh)6(H2O)3]Cl at 300 degrees C followed by alcoholysis of the product gives the new vanadium complexes [V6O6(PhCO2)6(CH3O)6(CH3OH)3] (1), [V6O6(PhCO2)6(C2H5O)6(C2H5OH)3] (2), [V6O6(PhCO2)6(C3H7O)6(C3H7OH)3] (3), [V6O6(PhCO2)6(C4H9O)6(C4H9OH)3] (4) and [V4O4(OCH3)6(O2CPh)2(HOCH3)2] (5). Complexes 2, 3 and 5 have been crystallographically characterised. DC magnetic susceptibility studies on complex shows antiferromagnetic coupling leading to a S = 0 spin ground state.

Benzoic Acid↗
PubMed2005

Effects of supercoiling on the sequence-specific photo-modification of DNA by a vanadium(V)-peroxo complex.

Sequence-specific photo-modification of DNA has been demonstrated, for the first time, in a vanadium(V)-peroxo complex, NH4[VO(O2)2(5,6-Me2phen)] (where 5,6-Me2phen = 5,6-dimethyl-1,10-phenanthroline). Using molecular cloning technique, a consensus sequence motif of 5'-G(A/G)TA(T/C)C was identified associated with the two specific photo-modification sites, 5'-ATC and 5'-TACC found on a plasmid DNA, pBluescript, by a modified Sanger sequencing technique. DNA supercoiling was shown to be a critical prerequisite for this observed sequence-specific photo-modification activity.

Base Sequence↗
PubMed1983

Tumor inhibition by metallocenes: ultrastructural localization of titanium and vanadium in treated tumor cells by electron energy loss spectroscopy.

The intracellular distribution patterns of the metal atoms titanium and vanadium after in vivo as well as in vitro treatment of Ehrlich ascites tumor with the antitumor agents titanocene dichloride (TDC) or vanadocene dichloride (VDC) have been investigated by use of electron energy loss spectroscopy (EELS). The metals were found mainly accumulated in the nuclear heterochromatin and, to a minor extent, in the nucleolus and in the cytoplasmic ribosomes. In connection with other experimental results it is argued that this accumulation is indicative of the molecular interaction of the metal-containing species with the nucleic acids, especially with the DNA.

Animals↗
PubMed2002

[Spectrophotometric determination of vanadium(V) through the formation of a tungstovanadophosphate-TMBPS charge transfer complex].

A new spectrophotometric method was developed for the determination of vanadium(V). The method was based on the formation of tungstovanadophosphate-3,3',5,5'-tetramethylbenzidine-N-propanesulfonic (TMBPS) charge transfer complex. The spectrophotometric measurements were directly carried out at 450 nm and the apparent molar absorptivity was 2.74 x 10(4) L.mol-1cm-1. The linear range of the determination was 0.02-1 microgram.mL-1. The sensitivity was enhancement with a flotation-extraction preconcentration method and the apparent molar absorptivity was 3.10 x 10(5) L.mol-1cm-1.

Alkanesulfonic Acids↗
PubMed1998

Stepwise Cluster Assembly Using VO(2)(acac) as a Precursor: cis-[VO(OCH(CH(3))(2))(acac)(2)], [V(2)O(2)(&mgr;-OCH(3))(2)(acac)(2)(OCH(3))(2)], [V(3)O(3){&mgr;,&mgr;-(OCH(2))(3)CCH(3)}(2)(acac)(2)(OC(2)H(5))], and [V(4)O(4)(&mgr;-O)(2)(&mgr;-OCH(3))(2)(&mgr;(3)-OCH(3))(2)(acac)(2)(OCH(3))(2)].2CH(3)CN(1).

The studies of an underexplored synthetic reagent, VO(2)(acac) (Hacac = acetylacetone) and semirational strategies for the formation of a complete series of simple vanadium(V) alkoxide clusters in alcohol-containing solvents. The neutral mono-, di-, tri-, and tetranuclear oxovanadium(V) complexes [V(2)O(2)(&mgr;-OCH(3))(2)(acac)(2)(OCH(3))(2)] (1), [V(4)O(4)(&mgr;-O)(2)(&mgr;-OCH(3))(2)(&mgr;(3)-OCH(3))(2)(acac)(2)(OCH(3))(2)].2CH(3)CN (2), [V(4)O(4)(&mgr;-O)(2)(&mgr;-OCH(3))(2)(&mgr;(3)-OCH(3))(2)(acac)(2)(OCH(3))(2)] (3), [V(3)O(3){&mgr;,&mgr;-(OCH(2))(3)CCH(3)}(2)(acac)(2)(OR)] (R = CH(3) (4), C(2)H(5) (5)), and cis-[VO(OCH(CH(3))(2))(acac)(2)] (6) with alkoxide and acac(-) ligands were obtained by reaction of VO(2)(acac) with a monoalcohol and/or a tridentate alcohol. The structures of complexes 1-3, 5, and 6 were determined by X-ray diffraction methods. Complex 1 crystallized in the monoclinic system, P2(1)/n, with a = 7.8668(5) Å, b = 15.1037(9) Å, c = 8.5879(5) Å, beta = 106.150(1) degrees, V = 980.1(1) Å(3), Z = 2, and R (wR2) = 0.040 (0.121). Complex 2 crystallized in the monoclinic system, P2(1)/n, with a = 8.531(2) Å, b = 14.703(3) Å, c = 12.574(2) Å, beta = 95.95(2) degrees, V = 1568.7(5) Å(3), Z = 2, and R (wR2) = 0.052 (0.127). Complex 3 crystallized in the triclinic system, P&onemacr;, with a = 8.5100(8) Å, b = 8.9714(8) Å, c = 10.3708(10) Å, alpha = 110.761(1) degrees, beta = 103.104(1) degrees, gamma = 100.155(1) degrees, V = 691.85(11) Å(3), Z = 1, and R (wR2) = 0.040 (0.105). Complex 5 crystallized in the monoclinic system, P2(1)/n, with a = 14.019(2) Å, b = 11.171(2) Å, c = 19.447(3) Å, beta = 109.18(1) degrees, V = 2876.5(8) Å(3), Z = 4, and R (wR2) = 0.062 (0.157). Complex 6 crystallized in the monoclinic system, P2(1)/n, with a = 15.0023(8) Å, b = 8.1368(1) Å, c = 26.5598(2) Å, beta = 95.744(1) degrees, V = 3225.89(8) Å(3), Z = 8, and R (wR2) = 0.060 (0.154). Complex 1 is a discrete, centrosymmetric dimer in which two vanadium atoms are bridged by two methoxide ligands. Compound 2 contains a V(4)O(4) eight-membered ring with both &mgr;-oxo and &mgr;-alkoxo bridging ligands; the ring is capped above and below by two triply bridging methoxo ligands. Compound 3 has the same structure as 2. The three vanadium atoms in complex 5 are linked by four bridging oxygen atoms from two tridentate thme(3)(-) ligands to form a V(3)O(4) chain in which V-O bonds alternate in length. The V-O(isopropoxo) bond in 6 is cis to V=O, and the V-O(acac) bond trans to the oxo group is relatively long. The V(2)O(2) rings of complex 1 and the mononuclear 1:2 complex can be considered to be the basic building block of the trinuclear complexes 4 and 5 and the tetranuclear complex 2, acting to extend the vanadium-oxide framework. (51)V and (1)H NMR spectroscopic studies of the solution state of complexes 1-6 revealed dramatic differences in structural and hydrolytic stability of these complexes. Compounds 1 and 3 only remained intact at low temperature in CDCl(3) solution, whereas the mononuclear compound 6 could remain at ambient temperature for approximately 10 h. Compound 4 only maintained its solid-state structure at low temperature in CDCl(3) solution, whereas compound 5 was significantly more stable. The structural integrity of oligomeric vanadium-oxygen frameworks increased significantly when the coordinating alkoxide group showed more resistance to exchange reactions than the methoxide group. The solid state and solution properties of this new group of complexes not only testify to the versatility of VO(2)(acac) as a vanadium(V) precursor but also raise questions relating to solution structure and properties of related vanadium complexes with insulin-mimetic properties and catalytic properties.

Journal Article↗
PubMed2001

Reaction of oxygen with 6-hydroxydopamine catalyzed by Cu, Fe, Mn, and V complexes: identification of a thermodynamic window for effective metal catalysis.

In the autoxidation of 6-hydroxydopamine, we investigated the reactivity of metals and metal complexes with a range of abilities to catalyse the reaction with oxygen. Comparing the catalytic effectiveness of aquo metals at pH 7.4, copper accelerated autoxidation 61-fold, iron 24-fold, manganese 7.3-fold, and vanadium 5.7-fold. Copper was thus the most effective catalyst despite being the weakest oxidant, indicating reduction of oxygen as rate limiting. EDTA, which decreases the reduction potential of Fe(III)/Fe(II), increased catalysis by iron 74% to almost that of aquo copper. Conversely, EDTA inhibited catalysis by copper, manganese, and vanadium. Desferrioxamine strongly inhibited catalysis by all of the metals. Histidine prevented catalysis by copper, accelerated catalysis by iron (43%), and had little effect on catalysis by manganese or vanadium. ADP and phytate inhibited catalysis by iron and manganese (50% or more), accelerated catalysis by vanadium (10-27%), and had no effect on catalysis by copper. The effects of the ligands largely reflected their influence on the reduction potential of the metal. Accordingly, addition of NaBr, which increases the reduction potential of Cu(II)/Cu(I), inhibited by 50%. In contrast, Na2SO4 augmented catalysis by copper 3-fold. Consistent with effects of OH- on reduction potentials and on metal coordination to 6-hydroxydopamine, an increase in pH to 8.0 decreased catalysis by copper and iron, but increased that of manganese 10-fold. In conclusion, the catalytic effectiveness of the metal-ligand complexes are largely attributable to their reduction potential, with steric accessibility playing secondary roles. The results delineate a window of catalytically effective potentials suitable for facile reduction and reoxidation by oxygen. By extension the results identify factors determining the pro- and antioxidant roles of ligands in metal mediated reduction of oxygen.

Adenosine Diphosphate↗
PubMed1997

Vanadium-mediated oxidation of NADH is enhanced by aluminium and inhibited by vitamin E and some copper (II) complexes.

The effect of aluminium on vanadium-mediated oxidation of NADH was examined. The oxidation of NADH was enhanced in the presence of aluminium. The effect was concentration dependent. Vitamin E and copper (II) complexes with superoxide dismutase (SOD)-like activities containing isobutyric acid hydrazine were tested for their effect on the vanadium-mediated oxidation of NADH. The stimulatory effect of aluminium was decreased upon addition of different concentrations of vitamin E and copper (II) complexes. These results indicate that the biological toxicity of aluminium may be attributed to its enhancement of the production of superoxide radicals (O2.-) in association with the accumulation of other trace elements such as vanadium.

Aluminum Compounds↗
PubMed2002

Supramol--a program for structure analysis of intercalates using molecular simulations: the structure of VOPO4*C6H4O2.

A method of structure analysis of intercalates has been developed that uses a combination of molecular simulations with powder diffraction. The program Supramol for the determination of intercalated structures uses crystal energy minimization in conjunction with powder diffraction data. The program solves the multiple minima problem in molecular mechanics, generating initial models systematically and searching for the global energy minimum by comparing the experimental and calculated diffraction patterns. The program is compatible with the Cerius2 modeling environment. Two intercalated crystal structures solved by Supramol are presented in the present paper: vanadyl phosphate intercalated with p-benzoquinone and the high temperature phase of vanadyl phosphate intercalated with dioxane. The structure of vanadyl phosphate intercalated with p-benzochinone is tetragonal, space group I4/ m, the unit cell parameters a=6.21 A, b=6.21 A, c=20.18 A and the density is rho=2.30 g x cm(-3), Z=4. The crystal structure of vanadyl phosphate intercalated with dioxane (high temperature phase) is monoclinic, space group C2/ m, unit cell parameters are: a= b=8.94 A, c=8.22 A, alpha=gamma=90 degrees, beta=106.30 degrees, Z=4, density 2.248 g x cm(-3).

Computer Simulation↗
PubMed1985

Vanadate, tungstate and molybdate activate rod outer segment phosphodiesterase in the dark.

Anionic activation of rod outer segment phosphodiesterase by vanadate, molybdate and tungstate is demonstrated. Comparisons are made to adenylate cyclase, which is known to be activated by vanadate and molybdate but not by tungstate. In view of the differences in anionic activation between these two important enzymatic regulators of intracellular cyclic nucleotide metabolism, it is possible that tungstate can be used as a selective probe for the effects of phosphodiesterase activity in photoreceptors and other cells. The known electrophysiological stimulation of Limulus photoreceptors by these anions is also interpreted in light of our results. If anionic production of quantum bumps in Limulus photoreceptors is mediated by changes in cyclic nucleotides, then the electrophysiological response of Limulus photoreceptors to tungstate may indicate a role for phosphodiesterase rather than adenylate cyclase in mediating light-induced cyclic nucleotide alterations in this cell.

3',5'-Cyclic-GMP Phosphodiesterases↗