451
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Buglyó P, Crans DC, Nagy EM, Lindo RL, Yang L, Smee JJ, Jin W, Chi LH, Godzala Iii ME, Willsky GR. Aqueous Chemistry of the VanadiumIII(VIII) and the VIII−Dipicolinate Systems and a Comparison of the Effect of Three Oxidation States of Vanadium Compounds on Diabetic Hyperglycemia in Rats. Inorg Chem 2005; 44:5416-27. [PMID: 16022540 DOI: 10.1021/ic048331q] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The aqueous vanadium(III) (V(III)) speciation chemistry of two dipicolinate-type complexes and the insulin-enhancing effects of V-dipicolinate (V-dipic) complexes in three different oxidation states (V(III), V(IV), and V(V)) have been studied in a chronic animal model system. The characterization of the V(III) species was carried out at low ionic strength to reflect physiological conditions and required an evaluation of the hydrolysis of V(III) at 0.20 M KCl. The aqueous V(III)-dipic and V(III)-dipic-OH systems were characterized, and complexes were observed from pH 2 to 7 at 0.2 M KCl. The V(III)-dipic system forms stable 1:2 complexes, whereas the V(III)-dipic-OH system forms stable 1:1 complexes. A comparison of these complexes with the V-pic system demonstrates that a second ligand has lower affinity for the V(III), presumably reflecting bidentate coordination of the second dipic(2)(-) to the V(III). The thermodynamic stability of the [V(III)(dipic)(2)](-) complex was compared to the stability of the corresponding V(IV) and V(V) complexes, and surprisingly, the V(III) complexes were found to be more stable than anticipated. Oral administration of three V-dipicolinate compounds in different oxidation states {H[V(III)(dipic)(2)H(2)O].3H(2)O, [V(IV)Odipic(H(2)O)(2)].2H(2)O, and NH(4)[V(V)O(2)dipic]} and the positive control, VOSO(4), significantly lowered diabetic hyperglycemia in rats with streptozotocin-induced diabetes. The diabetic animals treated with the V(III)- or V(IV)-dipic complexes had blood glucose levels that were statistically different from those of the diabetic group. The animals treated with the V(V)-dipic complex had the lowest blood glucose levels of the treated diabetic animals, which were statistically different from those of the diabetic group at all time points. Among the diabetic animals, complexation to dipic increased the serum levels of V after the administration of the V(V) and V(IV) complexes but not after the administration of the V(III) complex when data are normalized to the ingested dose of V. Because V compounds differing only in oxidation state have different biological properties, it is implied that redox processes must be important factors for the biological action of V compounds. We observe that the V(V)-dipic complex is the most effective insulin-enhancing agent, in contrast to previous studies in which the V(IV)-maltol complex is the most effective. We conclude that the effectiveness of complexed V is both ligand and oxidation state dependent.
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Affiliation(s)
- Péter Buglyó
- Department of Inorganic and Analytical Chemistry, University of Debrecen, P.O. Box 21, H-4010 Debrecen, Hungary
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452
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Yang XG, Yang XD, Yuan L, Wang K, Crans DC. The permeability and cytotoxicity of insulin-mimetic vanadium compounds. Pharm Res 2005; 21:1026-33. [PMID: 15212169 DOI: 10.1023/b:pham.0000029293.89113.d5] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE The aim of this study was to investigate the mechanism of permeation and cytotoxicity of vanadium compounds, [VO(acac)2], [VO(ma)2], and vanadate. METHODS Absorptive transport were carried out in Caco-2 monolayers grown on transwell inserts. Vanadium was quantified using inductively coupled plasma atomic emission spectrometry (ICP-AES). The change of Caco-2 cells in the microvilli morphology and F-actin structure was visualized by transmission electron microscopy and confocal laser scanning microscopy. RESULTS The three vanadium compounds were taken up by Caco-2 cells via simple passive diffusion. [VO(acac)2] were mainly transcellularly transported and exhibited the highest apparent permeabilty coefficients (8.2 x 10(-6) cm(-1)). The cell accumulation of [VO(acac)2] was found to be greater than that of [VO(ma)2], and vanadate caused much less accumulation than the other two compounds. Vanadium compounds induced intracellular reactive oxygen species, reduced the transepithelial electric resistance, caused morphological change in microvilli, and led to different perturbation of F-actin structure. CONCLUSIONS The three compounds exhibited different permeability due to different diffusion process and cellular uptake. The toxicity of vanadium complexes on Caco-2 monolayer involved F-actin-related change of tight junction and impairment of microvilli. The toxicity was also related to elevated intracellular reactive oxygen species (ROS) and their cellular accumulation.
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Affiliation(s)
- Xiao-Gai Yang
- Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing 100083, China.
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453
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Liboiron BD, Thompson KH, Hanson GR, Lam E, Aebischer N, Orvig C. New insights into the interactions of serum proteins with bis(maltolato)oxovanadium(IV): transport and biotransformation of insulin-enhancing vanadium pharmaceuticals. J Am Chem Soc 2005; 127:5104-15. [PMID: 15810845 DOI: 10.1021/ja043944n] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Significant new insights into the interactions of the potent insulin-enhancing compound bis(maltolato)oxovanadium(IV) (BMOV) with the serum proteins, apo-transferrin and albumin, are presented. Identical reaction products are observed by electron paramagnetic resonance (EPR) with either BMOV or vanadyl sulfate (VOSO4) in solutions of human serum apo-transferrin. Further detailed study rules out the presence of a ternary ligand-vanadyl-transferrin complex proposed previously. By contrast, differences in reaction products are observed for the interactions of BMOV and VOSO4 with human serum albumin (HSA), wherein adduct formation between albumin and BMOV is detected. In BMOV-albumin solutions, vanadyl ions are bound in a unique manner not observed in comparable solutions of VOSO4 and albumin. Presentation of chelated vanadyl ions precludes binding at the numerous nonspecific sites and produces a unique EPR spectrum which is assigned to a BMOV-HSA adduct. The adduct species cannot be produced, however, from a solution of VOSO4 and HSA titrated with maltol. Addition of maltol to a VOSO4-HSA solution instead results in formation of a different end product which has been assigned as a ternary complex, VO(ma)(HSA). Furthermore, analysis of solution equilibria using a model system of BMOV with 1-methylimidazole (formation constant log K1 = 4.5(1), by difference electronic absorption spectroscopy) lends support to an adduct binding mode (VO(ma)2-HSA) proposed herein for BMOV and HSA. This detailed report of an in vitro reactivity difference between VOSO4 and BMOV may have bearing on the form of active vanadium metabolites delivered to target tissues. Albumin binding of vanadium chelates is seen to have a potentially dramatic effect on pharmacokinetics, transport, and efficacy of these antidiabetic chelates.
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Affiliation(s)
- Barry D Liboiron
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, Canada, V6T 1Z1
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454
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Haratake M, Fukunaga M, Ono M, Nakayama M. Synthesis of vanadium(IV,V) hydroxamic acid complexes and in vivo assessment of their insulin-like activity. J Biol Inorg Chem 2005; 10:250-8. [PMID: 15806386 DOI: 10.1007/s00775-005-0634-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2004] [Accepted: 02/15/2005] [Indexed: 10/25/2022]
Abstract
We synthesized vanadyl (oxidation state +IV) and vanadate (oxidation state +V) complexes with the same hydroxamic acid derivative ligand, and assessed their glucose-lowering activities in relation to the vanadium biodistribution behavior in streptozotocin-induced diabetic mice. When the mice received an intraperitoneal injection of the complexes, the vanadate complex more effectively lowered the elevated glucose levels compared with the vanadyl one. The glucose-lowering effect of the vanadate complex was linearly related to its dose within the range from 2.5 to 7.5 mg V/kg. In addition, pretreatment of the vanadate complex induced a larger insulin-enhancing effect than the vanadyl complex. Both complexes were more effective than the corresponding inorganic vanadium compounds. The vanadyl and vanadate complexes, but not the inorganic vanadium compounds, resulted in almost the same organ vanadium distribution. Consequently, the observed differences in the insulin-like activity between the complexes would reflect the potency of the two compounds in the +IV and +V oxidation states in the subcellular region.
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Affiliation(s)
- Mamoru Haratake
- Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, 852-8521, Japan.
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455
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Preparation and characterisation of oxovanadium(IV) complexes derived from 2,6-diformyl-4-methylphenol and l-His and l-Ala. Spectroscopic study of the system VIVO2++BDF–His. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2004.11.050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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456
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Monga V, Thompson KH, Yuen VG, Sharma V, Patrick BO, McNeill JH, Orvig C. Vanadium Complexes with Mixed O,S Anionic Ligands Derived from Maltol: Synthesis, Characterization, and Biological Studies. Inorg Chem 2005; 44:2678-88. [PMID: 15819553 DOI: 10.1021/ic0486926] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Four mixed O,S binding bidentate ligand precursors derived from maltol (3-hydroxy-2-methyl-4-pyrone) have been chelated to vanadium to yield new bis(ligand)oxovanadium(IV) and tris(ligand)vanadium(III) complexes. The four ligand precursors include two pyranthiones, 3-hydroxy-2-methyl-4-pyranthione, commonly known as thiomaltol (Htma), and 2-ethyl-3-hydroxy-4-pyranthione, commonly known as ethylthiomaltol (Hetma), as well as two pyridinethiones, 3-hydroxy-2-methyl-4(H)-pyridinethione (Hmppt) and 3-hydroxy-1,2-dimethyl-4-pyridinethione (Hdppt). Vanadium complex formation was confirmed by elemental analysis, mass spectrometry, and IR and EPR (where possible) spectroscopies. The X-ray structure of oxobis(thiomaltolato)vanadium(IV),VO(tma)(2), was also determined; both cis and trans isomers were isolated in the same asymmetric unit. In both isomers, the two thiomaltolato ligands are arranged around the base of the square pyramid with the V=O linkage perpendicular; the vanadium atom is slightly displaced from the basal plane [V(1) = 0.656(3) A, V(2) = 0.664(2) A]. All of the new complexes were screened for insulin-enhancing effectiveness in streptozotocin-induced diabetes in rats, and VO(tma)(2) was profiled metabolically for urinary vanadium and ligand clearance by GFAAS and ESIMS, respectively. The new vanadium complexes did not lower blood glucose levels acutely, possibly because of rapid dissociation and excretion.
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Affiliation(s)
- Vishakha Monga
- Medicinal Inorganic Chemistry Group, Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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457
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Thompson KH, Chiles J, Yuen VG, Tse J, McNeill JH, Orvig C. Comparison of anti-hyperglycemic effect amongst vanadium, molybdenum and other metal maltol complexes. J Inorg Biochem 2005; 98:683-90. [PMID: 15134913 DOI: 10.1016/j.jinorgbio.2004.01.006] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2003] [Revised: 01/08/2004] [Accepted: 01/13/2004] [Indexed: 11/16/2022]
Abstract
A wide variety of vanadium-containing complexes have been tested, both in vivo and in vitro, as possible therapeutic agents for the oral treatment of type 2 diabetes mellitus. None so far has surpassed bis(maltolato)oxovanadium(IV) (BMOV) for glucose- and lipid-lowering in an orally available formulation. Ligand choice is clearly an important factor in pharmacological efficacy of vanadium compounds as insulin enhancing agents. In this study, we kept the ligand and dose the same, varying instead the metal ion bound to the maltolato ligand in a series of binary complexes of neutral charge. A requirement for vanadyl ion as the metal ion of choice was apparent; no other metal ion tested served as a suitable substitute. Amongst [MoO(2)](2+), Co(II), Cu(II), Cr(III), and Zn(II), only [MoO(2)](2+) and Co(II) showed any hypoglycemic activity at the ED(50) dose for bis(maltolato)oxovanadium(IV), 0.6 mmolkg(-1) by oral gavage in streptozotocin (STZ)-diabetic rats within 72 h of administration of compound.
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Affiliation(s)
- Katherine H Thompson
- Medicinal Inorganic Chemistry Group, Chemistry Department, University of British Columbia, Vancouver, BC, Canada V6T 1Z1.
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458
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Ghosh T, Bhattacharya S, Das A, Mukherjee G, Drew MG. Synthesis, structure and solution chemistry of mixed-ligand oxovanadium(IV) and oxovanadium(V) complexes incorporating tridentate ONO donor hydrazone ligands. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2004.11.015] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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459
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Mahroof-Tahir M, Brezina D, Fatima N, Choudhary MI. Synthesis and characterization of mononuclear oxovanadium(IV) complexes and their enzyme inhibition studies with a carbohydrate metabolic enzyme, phosphodiesterase I. J Inorg Biochem 2005; 99:589-99. [PMID: 15702518 DOI: 10.1016/j.jinorgbio.2004.11.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The increasing interest in vanadium coordination chemistry is based on its well-established chemical and biological functions. A beta-diketonato complex of oxovanadium(IV) is known to be having numerous catalytic applications and also exhibits promising insulin mimetic properties. In continuation of our structure activity relationship studies of metal complexes, we report herein the synthesis and characterization of the vanadium complexes of beta-diketonato ligand system with systematic variations of electronic and steric factors. Two complexes, VO(tmh)(2) (tmh = 2,2,6,6,-tetramethyl-3,5-heptanedione), and VO(hd)(2) (hd = 3,5-heptanedione) were synthesized and characterized by using different spectroscopic techniques. Elemental and mass spectral analysis supports the presence of two beta-diketonato ligands per VO(2+) unit. UV-Vis spectra in different solvents indicate coordination of coordinating solvent molecules at sixth position resulting in red shift of the band I transition. NMR and IR spectra reveal binding of coordinating solvent molecule at vacant sixth position trans to oxo group without releasing beta-diketonato ligands. Enzyme inhibition studies of these and other related oxovanadium(IV) complexes with beta-diketonato ligand system are conducted with snake venom phosphodiesterase I (SPVDE). All of these complexes showed significant inhibitory potential and were found to be non-competitive inhibitors against this enzyme.
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460
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Xie M, Gao L, Li L, Liu W, Yan S. A new orally active antidiabetic vanadyl complex – bis(α-furancarboxylato)oxovanadium(IV). J Inorg Biochem 2005; 99:546-51. [PMID: 15621288 DOI: 10.1016/j.jinorgbio.2004.10.033] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2004] [Revised: 10/21/2004] [Accepted: 10/22/2004] [Indexed: 11/20/2022]
Abstract
Bis(alpha-furancarboxylato)oxovanadium(IV)--a new orally active antidiabetic vanadyl complex has been synthesized, characterized, and tested for bioactivity as insulin-enhancing agents. The complex was administered intragastrically to both normal and STZ-diabetic rats for 4 weeks. The results show that the complex at a dose of 10.0 and 20.0 mg V kg(-1), could significantly lower the blood glucose level rats and ameliorated impaired glucose tolerance in STZ-diabetic, but not in normal rats. It was suggested that the complex exerted an antidiabetic effect in STZ-diabetic rats, which maybe was related to increasing the sensitivity to insulin.
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Affiliation(s)
- Mingjin Xie
- Deparment of Chemistry, Nankai University, Tianjin 300071, PR China.
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461
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Correia I, Pessoa JC, Duarte MT, da Piedade MFM, Jackush T, Kiss T, Castro MMCA, Geraldes CFGC, Avecilla F. Vanadium(IV andV) Complexes of Schiff Bases and Reduced Schiff Bases Derived from the Reaction of Aromatico-Hydroxyaldehydes and Diamines: Synthesis, Characterisation and Solution Studies. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400481] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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462
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Jin Y, Lee HI, Pyo M, Lah MS. A linear trinuclear mixed valence vanadium(v/iv/v) complex: synthesis, characterization, and solution behavior. Dalton Trans 2005:797-803. [PMID: 15702192 DOI: 10.1039/b500169m] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction between vanadium(III) acetylacetonate and N-hexanoylsalicylhydrazide (H3hshz) yields a linear trinuclear mixed valence vanadium(V/IV/V) complex, V3O3(hshz)2(OEt)2, 1 (where hshz3- is a triply deprotonated trianionic N-hexanoyl salicylichydrazidate), with a pseudo C2 symmetry. A V(IV)O2+ group is at the center of complex 1 and is spanned by two terminal vanadium(V) ions with a square pyramidal geometry bridged via hydrazido ligands. In the crystalline form, the oxo group of the central vanadium(IV) ion is weakly coordinated to one of the terminal square pyramidal vanadium(V) ions of the neighboring trinuclear complex to form a dimeric structure. These dimers are linked via bis mu-alkoxo bridges to form a one-dimensional zigzag chain structure. In chloroform or methylene dichloride, the weak linkages between the trinuclear complexes present in the crystalline form are broken, and only the mixed valence trinuclear complex can be identified. In dimethyl sulfoxide or dimethylformamide, the trinuclear complex partially dissociates, and the unligated ligands remain in equilibrium with the trinuclear complex.
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Affiliation(s)
- Yinshi Jin
- Department of Chemistry and Applied Chemistry, College of Science and Technology, Hanyang University, 1271 Sa-l0-dong, Ansan, Kyunggi-do, 426-791, Korea
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463
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Wong SY, Wai-Yin Sun R, Chung NPY, Lin CL, Che CM. Physiologically stable vanadium(iv) porphyrins as a new class of anti-HIV agents. Chem Commun (Camb) 2005:3544-6. [PMID: 16010318 DOI: 10.1039/b503535j] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The water soluble oxovanadium(IV) tetraarylporphyrin has demonstrated excellent solution stability against glutathione reduction and high potency (5 microM, 97% inhibition) in inhibiting HIV-1 replication in Hut/CCR5 cells.
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Affiliation(s)
- Suk-Yu Wong
- Department of Chemistry and Open Laboratory of Chemical Biology of the Institute of Molecular Technology for Drug Discovery and Synthesis, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, China
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464
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Zborowski K, Grybos R, Proniewicz LM. Molecular structures of oxovanadium(IV) complexes with maltol and kojic acid: a quantum mechanical study. INORG CHEM COMMUN 2005. [DOI: 10.1016/j.inoche.2004.11.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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465
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Maurya M, Agarwal S, Bader C, Rehder D. Dioxovanadium(V) Complexes of ONO Donor Ligands Derived from Pyridoxal and Hydrazides: Models of Vanadate-Dependent Haloperoxidases. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400211] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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466
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Majithiya JB, Balaraman R, Giridhar R, Yadav MR. Effect of bis[curcumino]oxovanadium complex on non-diabetic and streptozotocin-induced diabetic rats. J Trace Elem Med Biol 2005; 18:211-7. [PMID: 15966569 DOI: 10.1016/j.jtemb.2004.12.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
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.
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Affiliation(s)
- Jayesh B Majithiya
- Pharmacy Department, Faculty of Technology and Engineering, M.S. University of Baroda, Kalabhavan, Baroda-390001, Gujarat, India.
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467
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Sam M, Hwang JH, Chanfreau G, Abu-Omar MM. Hydroxyl Radical is the Active Species in Photochemical DNA Strand Scission by Bis(peroxo)vanadium(V) Phenanthroline. Inorg Chem 2004; 43:8447-55. [PMID: 15606193 DOI: 10.1021/ic0486419] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Bis(peroxo)vanadium(V) complexes are widely investigated as anticancer agents. They exert their antitumor and cyctotoxic effects through inhibition of tyrosine phosphatases and DNA cleavage, respectively. The latter process remains poorly understood. The mechanism of DNA cleavage by NH(4)[(phen)V(O)(eta(2)-O(2))(2)] (phen = 1,10-phenanthroline) was investigated. Kinetic studies on DNA cleavage revealed that the complex is a single-strand nicking agent with no specificity. EPR experiments using 2,2,6,6-tetramethyl-4-piperidone (TMP) and 5,5'-dimethyl-1-pyrroline-N-oxide (DMPO) as spin-traps for singlet oxygen and hydroxyl radical, respectively, implicated hydroxyl radical production upon photodecomposition of bis(peroxo)vanadium(V). This was corroborated by benzoate inhibition of DNA strand scission and stoichiometric oxidation of 2-propanol to acetone upon irradiation of bis(peroxo)vanadium(V) phenanthroline. High-resolution polyacrylamide gel analysis of the vanadium cleavage reaction and [Fe(II)EDTA](2)(-)/H(2)O(2) resulted in comigration of "ladder" pattern bands, which superimposed when both reactions were run on the same lane. These findings identify hydroxyl radical produced from the photooxidation of the peroxo ligand on vanadium as the active species in DNA cleavage.
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Affiliation(s)
- Mui Sam
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA
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468
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Kanamori K, Nishida K, Miyata N, Shimoyama T, Hata K, Mihara C, Okamoto KI, Abe Y, Hayakawa S, Matsugo S. Mononuclear and Dinuclear Monoperoxovanadium(V) Complexes with a Hetero Ligand. 1.1 Self-Decomposition Reaction, Detection of Reactive Oxygen Species, and Oxidizing Ability. Inorg Chem 2004; 43:7127-40. [PMID: 15500351 DOI: 10.1021/ic030292f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A mononuclear peroxovanadium(V) complex with histamine-N,N-diacetate (histada), K[VO(O(2))(histada)], and a dinuclear peroxovanadium(V) complex with 2-oxo-1,3-diaminopropane-N,N,N',N'-tetraacetate (dpot), Cs(3)[(VO)(2)(O(2))(2)(dpot)], were prepared and characterized. The self-decomposition reaction was examined for these peroxovanadium(V) complexes as well as for K[VO(O(2))(cmhist)] (cmhist = N-carboxymethylhistidinate). The reaction profiles depicted by the absorbance change in the UV-vis spectrum show a sigmoid shape with an induction period. The induction period is reduced by the addition of acid, fluoride, thiocyanate, VO(2+), VO(2)(+), and trolox compared to the solution containing perchlorate. On the other hand, the induction period was elongated by the addition of chloride, bromide, and 2-tert-butyl-p-cresol. These behaviors are discussed on the basis of a radical chain mechanism. The self-decomposition reactions have also been followed by the (1)H and (51)V NMR and EPR spectra. These spectral studies as well as the UV-vis spectral study indicate that vanadium(V) is partly reduced to vanadium(IV) in the self-decomposition process. The histada complex yields a mixed-valence dinuclear complex in a concentrated solution, and the dpot complex yields a mixed-valence tetranuclear complex. The reduction of vanadium ion suggests that the peroxo ligand may act as a reducing agent. In order to know the fate of the peroxo ligand, we tried to detect superoxide anion and hydroxyl radical, which were anticipated to be produced in the self-decomposition process. The formation of superoxide anion was spectrophotometrically confirmed using two independent methods, including the reduction of cytochrome c and the reduction of sodium 4-[3-(iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1). The formation of hydroxyl radical was confirmed by an EPR spin trapping technique. The oxidizing abilities of the peroxovanadium(V) complexes toward bovine serum albumin (BSA) were also evaluated. In the protein carbonyl assay, it was found that the total amount of protein carbonyl in BSA was increased by the reaction with the peroxovanadium complexes in the concentration-dependent manner. In addition, the oxidation of sulfhydryl group in BSA induced by the peroxovanadium complexes was confirmed.
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Affiliation(s)
- Kan Kanamori
- Department of Chemistry, Faculty of Science, Toyama University, Gofuku 3190, Toyama 930-8555, Japan.
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469
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Adachi Y, Yoshida J, Kodera Y, Kato A, Yoshikawa Y, Kojima Y, Sakurai H. A new insulin-mimetic bis(allixinato)zinc(II) complex: structure?activity relationship of zinc(II) complexes. J Biol Inorg Chem 2004; 9:885-93. [PMID: 15378407 DOI: 10.1007/s00775-004-0590-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2004] [Accepted: 07/30/2004] [Indexed: 10/26/2022]
Abstract
During the investigation of the development of insulin-mimetic zinc(II) complexes with a blood glucose-lowering effect in experimental diabetic animals, we found a potent bis(maltolato)zinc(II) complex, Zn(ma)(2), exhibiting significant insulin-mimetic effects in a type 2 diabetic animal model. By using this Zn(ma)(2) as the leading compound, we examined the in vitro and in vivo structure-activity relationships of Zn(ma)(2) and its related complexes. The in vitro insulin-mimetic activity of these complexes was determined by the inhibition of free fatty acid release and the enhancement of glucose uptake in isolated rat adipocytes treated with epinephrine. A new Zn(II) complex with allixin isolated from garlic, Zn(alx)(2), exhibited the highest insulin-mimetic activity among the complexes analyzed. The insulin-mimetic activity of the Zn(II) complexes examined strongly correlated (correlation coefficient=0.96) with the partition coefficient (log P) of the ligand, indicating that the activity of Zn(ma)(2)-related complexes depends on the lipophilicity of the ligand. The blood glucose-lowering effects of Zn(alx)(2) and Zn(ma)(2) were then compared, and both complexes were found to normalize hyperglycemia in KK- A(y) mice after a 14-day course of daily intraperitoneal injections. However, Zn(alx)(2) improved glucose tolerance in KK- A(y) mice much more than did Zn(ma)(2), indicating that Zn(alx)(2) possesses greater in vivo anti-diabetic activity than Zn(ma)(2). In addition, Zn(alx)(2) improved leptin resistance and suppressed the progress of obesity in type 2 diabetic KK- A(y) mice. On the basis of these observations, we conclude that the Zn(alx)(2) complex is a novel potent candidate for the treatment of type 2 diabetes mellitus.
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Affiliation(s)
- Yusuke Adachi
- Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, 607-8414 Kyoto, Japan
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470
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Bayot D, Tinant B, Devillers M. Spectroscopic and Structural Characterizations of Novel Water-Soluble Tetraperoxo and Diperoxo[polyaminocarboxylato bis(N-oxido)]tantalate(V) Complexes. Inorg Chem 2004; 43:5999-6005. [PMID: 15360249 DOI: 10.1021/ic049639k] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
New water-soluble homoleptic peroxo complexes and heteroleptic peroxo-polyaminocarboxylato (PAC) complexes of tantalum(V) have been prepared. In the case of the peroxo-PAC complexes, the synthesis in the presence of excess H2O2 leads to the oxidation of the nitrogen atoms of the ligand into N-oxides. The compounds correspond to the general formula (gu)3[Ta(O2)2(LO2)] x xH2O (gu = guanidinium, L = edta or pdta) in which H4LO2 refers to the bis(N-oxide) derivative of the PAC ligand. The TaV complexes have been characterized on the basis of elemental and thermal analysis and by IR and 13C and 15N NMR spectroscopy. These last two spectroscopic methods have been used to suggest the coordination mode of the PAC ligand in the complexes. ESI mass spectrometry measurements have also been carried out for the peroxo-PAC compounds. The crystal structures of the homoleptic tetraperoxotantalate, (gu)3[Ta(O2)4] (1), and the heteroleptic complex, (gu)3[Ta(O2)2(edtaO2)] x 2.32H2O x 0.68H2O2 (2b), have been determined, showing, for both cases, an 8-fold-coordinated Ta atom surrounded either by four bidentate peroxides or by two peroxides and one tetradentate edtaO2 ligand.
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Affiliation(s)
- Daisy Bayot
- Unité de Chimie des Matériaux Inorganiques et Organiques, Université Catholique de Louvain, Place Louis Pasteur 1, B-1348 Louvain-la-Neuve, Belgium
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471
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Gorzsás A, Getty K, Andersson I, Pettersson L. Speciation in the aqueous H+/H2VO4-/H2O2/citrate system of biomedical interest. Dalton Trans 2004:2873-82. [PMID: 15349160 DOI: 10.1039/b409429h] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The speciation in the quaternary aqueous H+/H2VO4-/H2O2/citrate (Cit3-) and H+/H2VO4-/Cit3-/L-(+)-lactate (Lac-) systems has been determined at 25 degrees C in the physiological medium of 0.150 M Na(Cl). A combination of 51V NMR integral intensities and chemical shift (Bruker AMX500) as well as potentiometric data (glass electrode) have been collected and evaluated with the computer program LAKE, which is able to treat multimethod data simultaneously. The pKa-values for citric acid have been determined as 2.94, 4.34 and 5.61. Altogether six vanadate-citrate species have been found in the ternary H+/H2VO4-/Cit3- system in the pH region 2-10, only two of which are mononuclear. Reduction of vanadium(V) becomes more pronounced at pH < 2. Solutions, in which reduction occurred to any extent, were excluded from all calculations. In the quaternary H+/H2VO4-/H2O2/Cit3- system, eight complexes have been found in addition to all binary and ternary complexes over the pH region 2-10, including three mononuclear species. Equilibria in general are fast, but the significant and rapid decomposition of peroxide in acidic solutions limited the final model to pH > 4. In the quaternary H+/H2VO4-/Cit3-/Lac- system, two mixed-ligand species have been determined, with the compositions V2CitLac2- and V2CitLac3- (pKa = 5.0). To our knowledge, this is the first time such complexes have been reported for vanadium(V). 51V NMR chemical shifts, compositions and formation constants are given, and equilibrium conditions are illustrated in distribution diagrams as well as the fit of the model to the experimental data. When suitable, structural proposals are given, based on 13C NMR measurements and available literature data of related compounds.
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Affiliation(s)
- András Gorzsás
- Department of Chemistry, Inorganic Chemistry, Umeå University, SE-90187, Umeå, Sweden.
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472
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Crans DC, Smee JJ, Gaidamauskas E, Yang L. The chemistry and biochemistry of vanadium and the biological activities exerted by vanadium compounds. Chem Rev 2004; 104:849-902. [PMID: 14871144 DOI: 10.1021/cr020607t] [Citation(s) in RCA: 989] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Debbie C Crans
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA.
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473
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Zhang Q, Lu C, Yang W, Chen S, Yu Y, He X, Yan Y, Liu J, Xu X, Xia C, Chen L, Wu X. Synthesis and characterization of vanadium(IV)–M (M=Mn, Zn) and vanadium(IV)–Ln (Ln=La, Nd) complexes with nitrilotriacetate ligands: {(NH4)2[(VIVO)2(μ2-O)(nta)2M(H2O)4]·2H2O}n and NH4[Ln(H2O)9][(VIVO)2 (μ2-O)(nta)2]. Polyhedron 2004. [DOI: 10.1016/j.poly.2004.05.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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474
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A three-dimensional structure of vanadium malonate: synthesis, characterization and X-ray structure of [Na2VO(C3H2O4)2(H2O)2]n. J Mol Struct 2004. [DOI: 10.1016/j.molstruc.2004.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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475
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Aznar CP, Deligiannakis Y, Tolis EJ, Kabanos T, Brynda M, Britt RD. ESE-ENDOR Study and DFT Calculations on Oxovanadium Compounds: Effect of Axial Anionic Ligands on the 51V Nuclear Quadrupolar Coupling Constant. J Phys Chem A 2004. [DOI: 10.1021/jp037560f] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Constantino P. Aznar
- Department of Chemistry, University of California, Davis, California, 95616, Department of Environmental and Natural Resources Management, Laboratory of Physical Chemistry, University of Ioannina, Pyllinis 9, 30100 Agrinio, Greece, and Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 451 10 Ioannina, Greece
| | - Yiannis Deligiannakis
- Department of Chemistry, University of California, Davis, California, 95616, Department of Environmental and Natural Resources Management, Laboratory of Physical Chemistry, University of Ioannina, Pyllinis 9, 30100 Agrinio, Greece, and Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 451 10 Ioannina, Greece
| | - Evangelos J. Tolis
- Department of Chemistry, University of California, Davis, California, 95616, Department of Environmental and Natural Resources Management, Laboratory of Physical Chemistry, University of Ioannina, Pyllinis 9, 30100 Agrinio, Greece, and Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 451 10 Ioannina, Greece
| | - Themistoklis Kabanos
- Department of Chemistry, University of California, Davis, California, 95616, Department of Environmental and Natural Resources Management, Laboratory of Physical Chemistry, University of Ioannina, Pyllinis 9, 30100 Agrinio, Greece, and Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 451 10 Ioannina, Greece
| | - Marcin Brynda
- Department of Chemistry, University of California, Davis, California, 95616, Department of Environmental and Natural Resources Management, Laboratory of Physical Chemistry, University of Ioannina, Pyllinis 9, 30100 Agrinio, Greece, and Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 451 10 Ioannina, Greece
| | - R. David Britt
- Department of Chemistry, University of California, Davis, California, 95616, Department of Environmental and Natural Resources Management, Laboratory of Physical Chemistry, University of Ioannina, Pyllinis 9, 30100 Agrinio, Greece, and Department of Chemistry, Section of Inorganic and Analytical Chemistry, University of Ioannina, 451 10 Ioannina, Greece
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476
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Synthesis of new dinuclear and mononuclear peroxovanadium(V) complexes containing biogenic co-ligands: a comparative study of some of their properties. Polyhedron 2004. [DOI: 10.1016/j.poly.2003.11.060] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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477
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Sakurai H, Inohara T, Adachi Y, Kawabe K, Yasui H, Takada J. A new candidate for insulinomimetic vanadium complex: synergism of oxovanadium(IV)porphyrin and sodium ascorbate. Bioorg Med Chem Lett 2004; 14:1093-6. [PMID: 14980642 DOI: 10.1016/j.bmcl.2003.12.081] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2003] [Revised: 12/18/2003] [Accepted: 12/26/2003] [Indexed: 10/26/2022]
Abstract
Vanadyl-meso-tetrakis(1-methylpyridinium-4-yl)porphyrin, VOTMpyP with the VO(N(4)) coordination mode, was found to have a potent insulinomimetic activity on the basis of in vitro and in vivo experiments. When the complex was given simultaneously with sodium ascorbate, the high blood glucose levels of type 1 diabetic model STZ-rats were lowered by synergistic effect, probably sustaining the vanadyl state by means of ascorbate distributed in the organs and tissues of animals. This is the first finding on not only the insulinomimetic vanadyl-porphyrin complex but also the occurrence of a synergistic effect of VOTMpyP and sodium ascorbate to lower the high blood glucose levels in diabetic animals.
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Affiliation(s)
- Hiromu Sakurai
- Kyoto Pharmaceutical University, Department of Analytical and Bioinorganic Chemistry, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan.
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478
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Bühl M, Schurhammer R, Imhof P. Peroxovanadate Imidazole Complexes as Catalysts for Olefin Epoxidation: Density Functional Study of Dynamics, 51V NMR Chemical Shifts, and Mechanism. J Am Chem Soc 2004; 126:3310-20. [PMID: 15012162 DOI: 10.1021/ja039436f] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A density functional study of [VO(O(2))(2)(Im)](-) (1, Im = imidazole) is presented, calling special attention to effects of dynamics and solvation on the (51)V chemical shift. According to Car-Parrinello molecular dynamics simulations, rotation of the Im ligand can be fast in the gas phase, but is more hindered in aqueous solution. In the latter, bonding between Im and V is reinforced, and dynamic averaging of GIAO-B3LYP magnetic shieldings affords a gas-to-liquid shift of ca. -100 ppm for delta((51)V). A complete catalytic cycle has been characterized for olefin epoxidation mediated by 1, using H(2)O(2) as oxidant. The rate-determining step is indicated to be initial oxygen atom transfer from 1 to the substrate via a spiro-like transition state. Substituent effects on this barrier are examined, and a significant decrease (by 2-6 kcal/mol) is revealed upon removal of the Im proton or upon complexation with a H-bond acceptor. Implications for the mechanism of the oxidative chemistry of vanadium-dependent haloperoxidases and requirements for prospective biomimetic analogues are discussed.
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Affiliation(s)
- Michael Bühl
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
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479
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Williams PAM, Barrio DA, Etcheverry SB, Baran EJ. Characterization of oxovanadium (IV) complexes of d-gluconic and d-saccharic acids and their bioactivity on osteoblast-like cells in culture. J Inorg Biochem 2004; 98:333-42. [PMID: 14729313 DOI: 10.1016/j.jinorgbio.2003.10.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Oxovanadium (IV) complexes of the alpha-hydroxycarboxylic ligands D-gluconic and D-saccharic acids of stoichiometry Na(2)[VO(gluconate)(2)].H(2)O, K(2)[VO(saccharate)(2)].4H(2)O, Na(4)[VO(gluconate)(2)].2H(2)O and K(5)[VO(saccharate)(2)].4H(2)O were obtained in aqueous solutions; the first two in acid, the other two in alkaline media. They were characterized by infrared and UV-Vis spectroscopies, thermoanalytical (thermogravimetric and differential thermal analysis) data and magnetic susceptibility measurements. The complexes were found to be mononuclear, possessing the VO(2+) moiety, and the thorough analysis of the spectral data allowed the determination of the characteristics of the metal-to-ligand interactions. The biological activities of these complexes on the proliferation, differentiation and glucose consumption were tested on osteoblast-like cells in culture. Comparisons of these effects and those of the oxovanadium (IV) cation and the free ligands were performed. Different behaviors could be observed for the complexes obtained at acidic or alkaline pH-values, as well as for the different cellular types. The free ligands did not show any biological effect.
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Affiliation(s)
- Patricia A M Williams
- Centro de Química Inorgánica, CONICET, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C. Correo 962, 1900 La Plata, Argentina
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480
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Ahmed M, Schwendt P, Marek J, Sivák M. Synthesis, solution and crystal structures of dinuclear vanadium(V) oxo monoperoxo complexes with mandelic acid: (NR4)2[V2O2(O2)2(mand)2]·xH2O [R=H, Me, Et; mand=mandelato(2−)=C8H6O32−]. Polyhedron 2004. [DOI: 10.1016/j.poly.2003.11.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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481
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Mono and oligonuclear vanadium complexes as catalysts for alkane oxidation: synthesis, molecular structure, and catalytic potential. Inorganica Chim Acta 2004. [DOI: 10.1016/j.ica.2003.05.005] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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482
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Nakai M, Obata M, Sekiguchi F, Kato M, Shiro M, Ichimura A, Kinoshita I, Mikuriya M, Inohara T, Kawabe K, Sakurai H, Orvig C, Yano S. Synthesis and insulinomimetic activities of novel mono- and tetranuclear oxovanadium(IV) complexes with 3-hydroxypyridine-2-carboxylic acid. J Inorg Biochem 2004; 98:105-12. [PMID: 14659639 DOI: 10.1016/j.jinorgbio.2003.09.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Two chargeless VO(IV) complexes with 3-hydroxypyridine-2-carboxylic acid (H2hpic), [VO(Hhpic-O,O)(Hhpic-O,N)(H2O)].3H2O (1) and the cyclic tetramer [(VO)4(mu-(hpic-O,O',N))4(H2O)4].8H3O (2), have been synthesized and characterized by elemental analysis, mass, infrared, electronic absorption, electron spin resonance (ESR) spectroscopies, and X-ray crystallography. Their coordination structures are similar to each other (and 1 is readily transformed into 2), but are quite different from that of bis(pyridine-2-carboxylato)oxovanadium(IV). The magnetic susceptibility of 2 indicates the presence of a weak ferromagnetic intramolecular interaction between the V atoms at low temperature, in addition to a weak antiferromagnetic intermolecular interaction. The ESR signal of 2 was broad, while 1 showed an eight-line hyperfine splitting pattern due to coupling of the unpaired electron with the 51V nucleus (I=7/2). The ESR spectrum and cyclic voltammogram of 2 clearly show that the cyclic tetramer remains intact in solution. The insulinomimetic activity of 1 and 2 was evaluated by means of in vitro measurements of the inhibition of free fatty acid release from epinephrine-treated isolated rat adipocytes. While 1 exerted higher insulinomimetic activity than VOSO4, the activity of 2 was significantly lower than that of VOSO4. Hence 2 appears to retain its cyclic structure during the in vitro test. These results indicate that the rational ligand design for VO complexes might be a promising approach to obtain superior insulinomimetic activity.
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Affiliation(s)
- Misaki Nakai
- Division of Material Science, Nara Women's University, Kitauoyanishimachi, Nara 630-8506, Japan
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483
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Yu X, Cai S, Chen Z. Spectroscopic studies on the interactions between a bioactive diperoxovanadate complex and pyridine. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2004; 60:391-396. [PMID: 14670503 DOI: 10.1016/s1386-1425(03)00236-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Interactions between a bioactive diperoxovanadate complex K3[OV(O2)2(C2O4)].H2O and pyridine in solution were studied by 2D NMR diffusion ordered spectroscopy (DOSY) as well as 1D 1H, 13C, 14N, and 51V NMR, variable temperature 1H NMR and spin-lattice relaxation time. Competitive coordination between C2O(4)(2-) and pyridine to [OV(O2)(2)](-) were observed in solution. A new species [OV(O2)2(Py)](-) was formed and its NMR data were reported for the first time. The experimental results indicated that both of the vanadium atom in species [OV(O2)2(C2O4)](3-) and [OV(O2)2(Py)](-) are six coordinated in solution. The conclusion was further supported by the results of ESI-MS. The newly-formed species is stable under the condition of near physiological pH value.
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Affiliation(s)
- Xianyong Yu
- Departments of Chemistry and Physics, State Key Laboratory for Physical Chemistry of Solid Surface, Xiamen University, Xiamen 361005, People's Republic of China
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484
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Maurya R, Rajput S. Oxovanadium(IV) complexes of bioinorganic and medicinal relevance: synthesis, characterization, and 3D molecular modeling and analysis of some oxovanadium(IV) complexes involving O,O-donor environment. J Mol Struct 2004. [DOI: 10.1016/j.molstruc.2003.08.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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485
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Andersson I, Gorzsás A, Pettersson L. Speciation in the aqueous H+/H2VO4-/H2O2/picolinate system relevant to diabetes research. Dalton Trans 2003:421-8. [PMID: 15252549 DOI: 10.1039/b313424e] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A detailed study of the quaternary aqueous H+/H2VO4-/H2O2/picolinate (Pi-) system has been performed at 25 degrees C in 0.150 M Na(Cl) medium using quantitative 51 V NMR (500 MHz) and potentiometric data (glass electrode). In the ternary H+/H2VO4-/Pi- system, six complexes have been found in the pH region 1-10. In the quaternary H+/H2VO4-/H2O2/Pi- system, eight additional complexes have been found. Generally, equilibria are fast in both systems. The rate of peroxide decomposition depends on the species in solution. Chemical shifts, compositions and formation constants for the species are given. Equilibrium conditions and the fit of the model to the experimental data are illustrated in distribution diagrams. Possible formation of mixed ligand species with imidazole, lactic acid and citric acid have been investigated and ruled out under the same experimental conditions. Structural proposals are given, based on 1)C NMR data and available crystal structures.
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Affiliation(s)
- Ingegärd Andersson
- Department of Chemistry, Inorganic Chemistry, Umeå University, SE-901 87 Umeå, Sweden
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486
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Preparation and characterisation of vanadium complexes derived from salicylaldehyde or pyridoxal and sugar derivatives. Inorganica Chim Acta 2003. [DOI: 10.1016/s0020-1693(03)00395-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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487
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Castro MC, Avecilla F, Geraldes CF, de Castro B, Rangel M. Study of the oxidation products of the VO(dmpp)2 complex in aqueous solution under aerobic conditions: comparison with the vanadate–dmpp system. Inorganica Chim Acta 2003. [DOI: 10.1016/s0020-1693(03)00473-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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488
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Yasui H, Kunori Y, Sakurai H. Specific Binding of Vanadyl Ion (VO2+) with Thiolate of the Cysteine-34 Residue in Serum Albumin, Demonstrated by CD Spectroscopy and Kinetic Property. CHEM LETT 2003. [DOI: 10.1246/cl.2003.1032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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489
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Hwang JH, Larson RK, Abu-Omar MM. Kinetics and Mechanistic Studies of Anticarcinogenic Bisperoxovanadium(V) Compounds: Ligand Substitution Reactions at Physiological pH and Relevance to DNA Interactions. Inorg Chem 2003; 42:7967-77. [PMID: 14632515 DOI: 10.1021/ic0350180] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bisperoxovanadium(V) compounds with bidentate ligands have shown tumor growth inhibition by cleaving DNA. The kinetics and mechanisms of ligand substitution reactions of two bisperoxovanadium(V) compounds [VO(O(2))(2)(bpy)](-) (bpVbpy) and [VO(O(2))(2)(phen)](-) (bpVphen) with entering ligands picolinic acid (pic) and dipicolinic acid (dipic) at physiological pH are reported, and its relevance to their DNA-cleavage activities are discussed. The products of the ligand substitution reactions with pic and dipic are the monoperoxo complexes [VO(O(2))(pic)(2)](-) and [VO(O(2))(dipic)(H(2)O)](-), respectively. (51)V NMR experiments indicate that bpVphen is substantially more inert in aqueous solution than bpVbpy. As a result, bpVbpy is more prone to ligand substitution and subsequent conversion to monoperoxo species. The rate of reaction for bpVbpy was faster than that of bpVphen by an order of magnitude, indicating that the ancillary ligand plays an important role in ligand substitution reactions. The ligand substitution reactions of bpVbpy feature first-order dependence on both [pic](T) and [dipic](T) whereas the substitution kinetics of bpVphen feature saturation behavior with dipic. The substitution reactions of both bpVbpy and bpVphen with pic showed first-order dependence on [H(+)] whereas no acid dependence was observed for the reactions with dipic. Hydrogen peroxide was determined to be a competitive inhibitor with respect to dipic. The ligand substitution reaction mechanisms and the rate laws consistent with these results are presented. The substitution reactions with pic and dipic proceed through different mechanisms; the substitution reactions with dipic proceed via solvolysis as the first step in the mechanisms whereas the reactions with pic bypass solvolysis to go through a mixed ligand monoperoxo vanadium intermediate.
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Affiliation(s)
- Jung H Hwang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA
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490
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Marzban L, McNeill JH. Insulin-like actions of vanadium: Potential as a therapeutic agent. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/jtra.10034] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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491
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Sakurai H, Yasui H. Structure-activity relationship of insulinomimetic vanadyl-picolinate complexes in view of their clinical use. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/jtra.10036] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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492
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Abstract
The wide use of the ligand 3-hydroxy-2-methyl-4-pyrone (maltol) in bioinorganic chemistry has prompted an effort to further exploit this ligand class by achieving an efficient, one-step synthesis of the chelator 3-hydroxy-2-methyl-4-thiopyrone (thiomaltol). Complexes of thiomaltol with nickel(II) and iron(III) have been prepared and studied by using UV-visible spectroscopy and electrochemical methods. In addition, both complexes as well as the free thiomaltol ligand have been structurally characterized by using single-crystal X-ray diffraction methods. The ligand is found to exert a strong trans influence on the structure of the complexes in the solid state with the nickel(II) and iron(III) complexes demonstrating a cis and fac geometry, respectively. The compounds described here should significantly expand the scope and utility of O,S-donor ligands derived from maltol and related precursors.
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Affiliation(s)
- Jana A Lewis
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, USA
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493
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Kawabe K, Sasagawa T, Yoshikawa Y, Ichimura A, Kumekawa K, Yanagihara N, Takino T, Sakurai H, Kojima Y. Synthesis, structure analysis, solution chemistry, and in vitro insulinomimetic activity of novel oxovanadium(IV) complexes with tripodal ligands containing an imidazole group derived from amino acids. J Biol Inorg Chem 2003; 8:893-906. [PMID: 14551811 DOI: 10.1007/s00775-003-0489-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2003] [Accepted: 08/19/2003] [Indexed: 10/26/2022]
Abstract
Structures, chemical properties, and in vitro insulinomimetic activities of new vanadyl [oxovanadium(IV), VO(2+)] complexes with five tripodal ligands containing an imidazole functionality were examined. The ligands, N-(carboxymethyl)- N-(4-imidazolylmethyl)amino acids, contain glycine, ( S)- and ( R)-alanine, and ( S)- and ( R)-leucine residues. The molecular structures of the latter four alanine- and leucine-containing complexes were determined by X-ray analysis. The coordination geometry around each vanadium center was octahedral, where an imino nitrogen occupied the apical site and two carboxylate oxygens, an imidazole nitrogen, and a water molecule coordinated in the equatorial plane. The spectroscopic properties of the complexes were characterized by means of IR, electronic absorption, and CD spectra. Acid dissociation constants (p K(a)) and protonation sites of the ligands were determined by a combination of potentiometric titrations and (1)H NMR spectra. The potentiometric study demonstrated that stability constants (log beta) were not so different among the present complexes (14.0-14.9) and a species of molecular complex with a 1:1 metal:ligand ratio existed predominantly at physiological pH 7.4. EPR parameters indicated that the species at pH 7.4 had an octahedral structure similar to the complex in the solid state. On the other hand, an EPR study in phosphate buffer (pH 7.4) suggested that inorganic phosphate coordinated to the vanadium center instead of the imidazole group in the presence of excess phosphate ion. Cyclic voltammograms in the phosphate buffer showed chemically reversible oxidation waves, whereas irreversible oxidation waves were observed in non-coordinating HEPES buffer. Moreover, the oxidation potential of each complex in phosphate buffer was more positive than that in HEPES buffer. Partition coefficients of the present complexes in a n-octanol/saline system were very low, probably due to hydrophilicity of the imidazole group. The in vitro insulinomimetic activities were estimated on the basis of the ability of the complexes to inhibit epinephrine-stimulated free fatty acid release from isolated rat adipocytes. The achiral glycine-derivative complex exhibited the highest insulinomimetic activity, which was higher than that of VOSO(4) as a positive control. Putting our previous observations together, it was found that the vanadyl complexes with tetradentate amino acid derivatives having no alkyl side chain tend to have high in vitro insulinomimetic activity.
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Affiliation(s)
- Kenji Kawabe
- Department of Chemistry, Graduate School of Science, Osaka City University, Japan
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494
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Sakurai H, Tamura A, Fugono J, Yasui H, Kiss T. New antidiabetic vanadyl–pyridone complexes: effect of equivalent transformation of coordinating atom in the ligand. Coord Chem Rev 2003. [DOI: 10.1016/s0010-8545(03)00031-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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495
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Sakurai H, Yasui H, Adachi Y. The therapeutic potential of insulin-mimetic vanadium complexes. Expert Opin Investig Drugs 2003; 12:1189-203. [PMID: 12831353 DOI: 10.1517/13543784.12.7.1189] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Throughout the world, the number of patients suffering from diabetes mellitus (DM) is increasing on a daily basis, probably due to change in lifestyle. DM is mainly classified as either insulin-dependent Type 1 or non-insulin-dependent Type 2, according to the definition of WHO. To treat DM, which has many severe complications, several types of insulin preparations and synthetic drugs for Type 1 and Type 2 DM, respectively, have been developed and are in clinical use. However, there are several problems concerning the insulin preparations and synthetic drugs, such as physical and mental pain due to daily insulin injections and defects involving side effects, respectively. Consequently, a new class of therapeutic agents is anticipated. For this purpose, vanadium-containing complexes are expected to treat or improve both types of DM by using unique characteristics of the transition metal. In this article, the current state of research on insulin-mimetic vanadium complexes are reviewed, with special focus on the paramagnetic vanadyl (+4 oxidation state of vanadium) complexes with different coordination modes. To analyse the blood glucose-lowering effects of the vanadyl complexes, new results on the organ distribution and pharmacokinetic analysis of the vanadyl state in the blood of rats are also described.
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Affiliation(s)
- Hiromu Sakurai
- Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, 5 Nakauchicho, Misasagi, Yamashinaku, Kyoto 607-8414, Japan.
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496
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Abstract
In the 21st century, patients suffering from diabetes mellitus (DM), a lifestyle-related disease, will increase more than in the 20th century. DM is threatening because of the development of many severe secondary complications, including atherosclerosis, microangiopathy, renal dysfunction and failure, cardiac abnormalities, diabetic retinopathy, and ocular disorders. Generally, DM is classified as either insulin-dependent type 1 or noninsulin-dependent type 2 DM. Type 1 DM is treated only by daily insulin injections; type 2 DM is treated by several types of synthetic therapeutic substances together with a controlled diet and physical exercise. Even with these measures, the daily necessity for several insulin injections can be painful both physically and mentally, whereas the synthetic therapeutic substances used over the long term often have side effects. For those reasons, the creation and development of a new class of pharmaceuticals for treatment of DM in the 21st century would be extremely desirable. In the last half of the 20th century, investigations of the relationships among diseases and micronutrients, such as iron, copper, zinc, and selenium, have been numerous. Research into the development of metallopharmaceuticals involving the platinum-containing anticancer drug, cisplatin, and the gold-containing rheumatoid arthritis drug, auranofin, has also been widespread. Such important findings prompted us to develop therapeutic reagents based on a new concept to replace either insulin injections or the use of synthetic drugs. After many trials, we noticed that vanadium might be very useful in the treatment of DM. Before the discovery of insulin by Banting and Best in 1921 and its clinical trial for treating DM, the findings in 1899, in which orally administered sodium vanadate (NaVO(3)) was reported to improve human DM, gave us the idea to use vanadium to treat DM. However, it has taken a long time to obtain a scientific explanation as to why the metal ion exhibits insulin-mimetic or blood-glucose lowering effects in in vitro and in vivo experiments. After investigations from many perspectives involving biochemistry and bioinorganic chemistry, vanadyl sulfate (VOSO(4)) and its complexes with several types of ligands have been proposed as useful for treating DM in experimental diabetic animals. On the basis of a mechanistic study, this article reports on recent progress regarding the development of antidiabetic vanadyl complexes, emphasizing that the vanadyl ion and its complexes are effective not only in treating or relieving both types of DM but also in preventing the onset of DM.
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Affiliation(s)
- Hiromu Sakurai
- Department of Analytical and Bioinorganic Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan.
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497
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Puerta DT, Cohen SM. Examination of novel zinc-binding groups for use in matrix metalloproteinase inhibitors. Inorg Chem 2003; 42:3423-30. [PMID: 12767177 DOI: 10.1021/ic026029g] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The tetrahedral zinc complex [(Tp(Ph,Me))ZnOH] (Tp(Ph,Me) = hydrotris(3,5-phenylmethylpyrazolyl)borate) was combined with 1-hydroxy-2(1H)-pyridinone, 3-hydroxy-2(1H)-pyridinone, 3-hydroxy-1-methyl-2(1H)-pyridinone, 3-hydroxy-1,2-dimethyl-4(1H)-pyridinone, 1-hydroxy-2(1H)-pyridinethione, and 3-hydroxy-2-methyl-4-pyrone to generate the complexes [(Tp(Ph,Me))Zn(ZBG)] (ZBG = zinc-binding group). These complexes were synthesized to explore the coordination geometry of potential novel zinc-binding groups for use in matrix metalloproteinase (MMP) inhibitors. The solid-state structures of all six metal complexes were determined by X-ray crystallography. These structures combined with IR and (1)H NMR data demonstrate that these ZBGs bind in a strong, bidentate fashion to the zinc(II) ion. Modeling studies indicate that these ZBGs can easily fit into the MMP active site. In an effort to develop more effective inhibitors of MMPs, this work has revealed molecular-level interactions for six potential new ZBGs.
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Affiliation(s)
- David T Puerta
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0358, USA
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498
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Turel I, Golobic A, Klavzar A, Pihlar B, Buglyó P, Tolis E, Rehder D, Sepcić K. Interactions of oxovanadium(IV) and the quinolone family member--ciprofloxacin. J Inorg Biochem 2003; 95:199-207. [PMID: 12763665 DOI: 10.1016/s0162-0134(03)00123-5] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The interactions of quinolone ciprofloxacin (cfH) and oxovanadium(IV) were studied by various methods. Green crystals of a complex [V(IV)O(cf)(2)(H(2)O)] were isolated and the molecular connectivities established, although the crystal structure was not perfectly refined due to the instability of the crystals. Based on a plausible interpretation of the data sets, two cf anions bidentately coordinate to a vanadyl cation through carboxylate and carbonyl oxygen atoms; in addition, there is a water molecule in the coordination sphere. Solution techniques (cyclic voltammetry, electronic and electron paramagnetic resonance spectroscopy, potentiometric measurements) confirmed the presence of various species in the solution, the composition of which strongly depends on the conditions in the system. The antibacterial activity of the complex against various microorganisms was tested and it was established that its activity is similar to that of free ciprofloxacin.
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Affiliation(s)
- Iztok Turel
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, 1000 Ljubljana, Slovenia.
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499
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Abstract
The growing awareness of the strong development of the toxicity of heavy metals upon their chemical forms has led to an increasing interest in the qualitative and quantitative determination of specific metal species. Speciation has therefore become an important topic of present-day analytical research. The development in the elemental speciation analysis by capillary electrophoresis (CE) is reviewed. Various CE separation modes and detection techniques applied are discussed. A comprehensive description of reported methods to date in CE speciation analysis including metals, metalloids and nonmetallic elements is demonstrated. Some examples are presented to demonstrate CE's ability to solve real-world speciation analysis with emphasis on the applications in biological and environmental samples. Further, some issues concerning the limitations and the future of CE with regard to speciation studies are also discussed.
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Affiliation(s)
- Yan-Ming Liu
- Department of Chemistry, Wuhan University, Wuhan, P. R. China
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500
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Kiss E, Kawabe K, Tamura A, Jakusch T, Sakurai H, Kiss T. Chemical speciation of insulinomimetic VO(IV) complexes of pyridine-N-oxide derivatives: binary and ternary systems. J Inorg Biochem 2003; 95:69-76. [PMID: 12763650 DOI: 10.1016/s0162-0134(03)00103-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In order to estimate the impact of the low-molecular-mass (l.m.m.) VO(IV) binders of blood serum on the potentially insulin-enhancing compound VO(HPO)(2) (HPO, 2-hydroxypyridine-N-oxide): and VO(MPO)(2) (MPO, 2-mercaptopyridine-N-oxide), the speciation in the binary system VO(IV)-HPO and VO(IV)-MPO and in the ternary systems VO(IV)-HPO(MPO)-ligand B (B=oxalate, lactate, citrate or phosphate) was studied by pH-potentiometry. The stability constants of the complexes formed were determined in aqueous solution at I=0.2 M (KCl) and T=25 degrees C. The most probable binding modes of the complexes were determined by EPR method. The pyridine-N-oxides were found to form very stable bis complexes, which are predominant in the pH range 2-7. The results in the ternary systems demonstrate that only the citrate is a strong enough VO(IV) binder to compete with the carrier ligands. The binding ability of the high-molecular-mass (h.m.m.) serum proteins albumin and transferrin were also assessed and transferrin was found to be an efficient binder molecule. The actual solution state of these compounds in blood serum is compared with that of other insulin-mimic VO(IV) complexes.
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Affiliation(s)
- Erzsébet Kiss
- Biocoordination Chemistry Research Group of Hungarian Academy of Sciences, University of Szeged, PO Box 440, H-6701 Szeged, Hungary
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