Synthesis of vanadium/propylene glycol complexes - …

The samples were synthesized by chemical synthesis according to the following manner. At First, 0.1g sodium metavanadate was completely dissolved in 100 mL pure water with stirring at room temperature. Ammonium chloride (1.2g) was then added to the solution until dissolve completely. The color of solution changed from muddy color to transparent color which after a few minutes changed to fuggy color. After 10 minutes, 0.5g, Cetyl trimethylammonium bromide (CTAB) was added to the solution and synthesis temperature was increased to 80oC. The color of solution changed from orange color to dark brown color. The pH was between 6 and 8 during the synthesis. After one hour, the color of solution changed to transparent yellow color. The product were evaporated for 2 hours, cooled to room temperature and finally calcined at 600oC for 4 hours. All analyses were done for samples without any washing and more purification. The specification of the size, structure and optical properties of the as-synthesis and annealed vanadium oxide nanoparticles were carried out. X-ray diffractometer (XRD) was used to identify the crystalline phase and to estimate the crystalline size. The XRD pattern were recorded with 2θ in the range of 4-85o with type X-Pert Pro MPD, Cu-Kα: λ = 1.54 Å. The morphology was characterized by field emission scanning electron microscopy (SEM) with type KYKY-EM3200, 25 kV and transmission electron microscopy (TEM) with type Zeiss EM-900, 80 kV. All the measurements were carried out at room temperature.

Synthesis of vanadium/propylene glycol complexes. - …

T1 - Synthesis, immunomodulation and cytotoxic effects of vanadium (IV) complexes

Synthesis of (Imido)vanadium(V) Complexes Containing …

Five coordination complexes of vanadium were synthesized and tested in vivo for their hypoglycemic activities and toxicity and were compared with the predictive data. Reasonable correspondence between the experimental and predicted values of toxicity and hypoglycemic activity for vanadium compounds indicates that GUSAR software may be successfully applied to explore the structure-activity relationships of metal complexes. Bis{tert-butyl[amino(imino)methyl]carbamato}oxovanadium(IV) which IC50 value was almost twice less than those obtained by vanadyl sulfate was identified as the most potent hypoglycemic agent among the synthesized compounds. We have shown that it may be possible to develop some vanadium compounds which have stronger selectivity against FFAs.

Synthesis of Mono- and Dinuclear Vanadium Complexes …

The most intense bands in the IR spectrum of the synthesized complex I correspond to vibrations of crystal water molecules (3450–3200 cm–1) and to the stretching vibrations of the oxodiperoxovanadium moiety: the band at 926 cm–1 is due to the V=O vibrations, the bands at 879 and 858 cm–1 correspond to O–O bond vibrations. The broad band at 586 cm–1 and the medium-intensity band at 624 cm–1 are produced by the symmetric and antisymmetric vibrations of the VO2 fragment, respectively. The positions of these bands coincide with published data to within 4 cm–1. The band at 766 cm–1, which virtually retains its position in the spectrum of crystalline 2, 2′-Bipy, and a number of weak bands in the region of 1200–950 cm–1 can be attributed to ligand vibrations. The positions and intensities of most of the 2, 2-Bipy bands in the IR spectrum of complex I, primarily in the region of 1700–1300 cm–1, are markedly different from those observed for ligand-free form 2, 2-Bipy (see abbreviation in), which is due to the conformational change that takes place in the 2, 2-Bipy molecule upon complexation: the trans-arrangement of the pyridine rings in the free ligand is changed for the cis-arrangement in the complex.

Synthetic, Structural, and Physical Studies of Vanadium(III) and Oxovanadium(IV/V) Complexes with Amidate Ligands

the Lewis acid character of the vanadium centers

N2 - Vanadium is known to exhibit several bioactivities and shows potential as a pharmaceutical drug. The current studies were conducted with the goal of synthesizing a new generation of oxovanadium(IV) complexes, investigating their effects on cancer cell proliferation and their immunomodulatory properties, and predicting possible structure activity relationships. The elucidation of the structures of the synthesized complexes was achieved using elemental analysis, conductivity measurements, magnetic property measurements, and IR and electronic spectroscopies. These studies suggest that the synthesized complexes have a binuclear structure. All of the complexes were evaluated on different cancer cell lines, including HeLa, PC-3, and C33A, and on the normal 3T3 fibroblast cells. Some of the compounds exhibited prominent inhibitory activities on the cervical cancer cell lines and the prostate cancer PC-3 cells. The immunomodulatory activity of the vanadium compounds was evaluated on human phagocytes for ROS (reactive oxygen species) production using luminol- and lucigenin-based chemiluminescence assays. No potent effect was exerted by the majority of the tested compounds on whole blood oxidative burst activity. A study of human T-cells proliferation in vitro on vanadium complexes was also conducted. The majority of the compounds were observed to exhibit potent inhibitory effects. The superoxide, nitric oxide and DPPH (2,2-diphenyl-1- picrylhydrazyl) radical scavenging properties were also determined.

[The vanadium compounds: chemistry, synthesis, insulinomimetic ..

AB - Vanadium is known to exhibit several bioactivities and shows potential as a pharmaceutical drug. The current studies were conducted with the goal of synthesizing a new generation of oxovanadium(IV) complexes, investigating their effects on cancer cell proliferation and their immunomodulatory properties, and predicting possible structure activity relationships. The elucidation of the structures of the synthesized complexes was achieved using elemental analysis, conductivity measurements, magnetic property measurements, and IR and electronic spectroscopies. These studies suggest that the synthesized complexes have a binuclear structure. All of the complexes were evaluated on different cancer cell lines, including HeLa, PC-3, and C33A, and on the normal 3T3 fibroblast cells. Some of the compounds exhibited prominent inhibitory activities on the cervical cancer cell lines and the prostate cancer PC-3 cells. The immunomodulatory activity of the vanadium compounds was evaluated on human phagocytes for ROS (reactive oxygen species) production using luminol- and lucigenin-based chemiluminescence assays. No potent effect was exerted by the majority of the tested compounds on whole blood oxidative burst activity. A study of human T-cells proliferation in vitro on vanadium complexes was also conducted. The majority of the compounds were observed to exhibit potent inhibitory effects. The superoxide, nitric oxide and DPPH (2,2-diphenyl-1- picrylhydrazyl) radical scavenging properties were also determined.

Vanadium Complexes with Mixed O,S Anionic Ligands …

N2 - The stoichiometry and thermodynamic stability of vanadium(IV/V) complexes of Triapine and two related α(N)-heterocyclic thiosemicarbazones (TSCs) with potential antitumor activity have been determined by pH-potentiometry, EPR and 51V NMR spectroscopy in 30% (w/w) dimethyl sulfoxide/water solvent mixtures. In all cases, mono-ligand complexes in different protonation states were identified. Dimethylation of the terminal amino group resulted in the formation of vanadium(IV/V) complexes with considerably higher stability. Three of the most stable complexes were also synthesized in solid state and comprehensively characterized. The biological evaluation of the synthesized vanadium complexes in comparison to the metal-free ligands in different human cancer cell lines revealed only minimal influence of the metal ion. Thus, in addition the coordination ability of salicylaldehyde thiosemicarbazone (STSC) to vanadium(IV/V) ions was investigated. The exchange of the pyridine nitrogen of the α(N)-heterocyclic TSCs to a phenolate oxygen in STSC significantly increased the stability of the complexes in solution. Finally, this also resulted in increased cytotoxicity activity of a vanadium(V) complex of STSC compared to the metal-free ligand.