@article {2370, title = {Glucosamine conjugates bearing N,N,O-donors: potential imaging agents utilizing the [M(CO)(3)](+) core (M = Re, Tc)}, journal = {Dalton Transactions}, number = {42}, year = {2009}, note = {ISI Document Delivery No.: 508YBTimes Cited: 2Cited Reference Count: 32Bowen, Meryn L. Lim, Nathaniel C. Ewart, Charles B. Misri, Ripen Ferreira, Cara L. Haefeli, Urs Adam, Michael J. Orvig, Chris}, pages = {9216-9227}, type = {Article}, abstract = {The design rationale, synthesis and radiolabeling evaluation of four glucosamine conjugated ligands for the [Tc-99m(CO)(3)](+) core is described. The capability to bind the tricarbonyl core is initially demonstrated using the cold surrogate [Re(CO)(3)](+). The four compounds are competent chelates in binding [Tc-99m(CO)(3)](+) as labeling studies show, with yields ranging from 79 to 96\% and the resulting complexes showing stability in the presence of competing chelates for 24 h at 37 degrees C. The rhenium complexes were tested for hexokinase-catalysed phosphorylation, and the technetium complexes were tested for GLUT-1 mediated cell uptake - they showed a small amount of uptake but it was not glucose dependent, suggesting that it was not via the GLUT-1 transporters.}, keywords = {BIOMOLECULES, EXPRESSION, GLUT-1, HEXOKINASE, IN-VITRO, METAL-COMPLEXES, TC-99M, technetium, TRANSPORTERS, TRICARBONYL COMPLEXES}, isbn = {1477-9226}, url = {://000270973800020}, author = {Bowen, M. L. and Lim, N. C. and Ewart, C. B. and Misri, R. and Ferreira, C. L. and Hafeli, U. and Adam,Michael J. and Orvig, Chris} } @article {2370, title = {Glucosamine conjugates bearing N,N,O-donors: potential imaging agents utilizing the [M(CO)(3)](+) core (M = Re, Tc)}, journal = {Dalton Transactions}, number = {42}, year = {2009}, note = {ISI Document Delivery No.: 508YBTimes Cited: 2Cited Reference Count: 32Bowen, Meryn L. Lim, Nathaniel C. Ewart, Charles B. Misri, Ripen Ferreira, Cara L. Haefeli, Urs Adam, Michael J. Orvig, Chris}, pages = {9216-9227}, type = {Article}, abstract = {The design rationale, synthesis and radiolabeling evaluation of four glucosamine conjugated ligands for the [Tc-99m(CO)(3)](+) core is described. The capability to bind the tricarbonyl core is initially demonstrated using the cold surrogate [Re(CO)(3)](+). The four compounds are competent chelates in binding [Tc-99m(CO)(3)](+) as labeling studies show, with yields ranging from 79 to 96\% and the resulting complexes showing stability in the presence of competing chelates for 24 h at 37 degrees C. The rhenium complexes were tested for hexokinase-catalysed phosphorylation, and the technetium complexes were tested for GLUT-1 mediated cell uptake - they showed a small amount of uptake but it was not glucose dependent, suggesting that it was not via the GLUT-1 transporters.}, keywords = {BIOMOLECULES, EXPRESSION, GLUT-1, HEXOKINASE, IN-VITRO, METAL-COMPLEXES, TC-99M, technetium, TRANSPORTERS, TRICARBONYL COMPLEXES}, isbn = {1477-9226}, url = {://000270973800020}, author = {Bowen, M. L. and Lim, N. C. and Ewart, C. B. and Misri, R. and Ferreira, C. L. and Hafeli, U. and Adam,Michael J. and Orvig, Chris} } @article {2628, title = {Glycosylated tetrahydrosalens as multifunctional molecules for Alzheimer{\textquoteright}s therapy}, journal = {Dalton Transactions}, number = {16}, year = {2009}, note = {ISI Document Delivery No.: 430GYTimes Cited: 8Cited Reference Count: 65Storr, Tim Scott, Lauren E. Bowen, Meryn L. Green, David E. Thompson, Katherine H. Schugar, Harvey J. Orvig, Chris}, pages = {3034-3043}, type = {Article}, abstract = {The tetrahydrosalens N,N{\textquoteright}-bis(2-hydroxybenzyl)-ethane-1,2-diamine (H2L1), N, N{\textquoteright}-bis(2-hydroxybenzyl)-(-)-1,2-cyclohexane-(1R, 2R)-diamine (H2L2), N,N{\textquoteright}-bis(2-hydroxybenzyl)-N,N{\textquoteright}-dimethyl-ethane-1,2-diamine (H2L3), N,N{\textquoteright}-bis(2-hydroxybenzyl)-N,N{\textquoteright}-dibenzyl-ethane-1,2diamine (H2L4), and N,N{\textquoteright}-bis(2-(4-tert-butyl) hydroxybenzyl)-ethane-1,2-diamine (H2L5), as well as their prodrug glycosylated forms, GL(1-5), have been prepared and evaluated in vitro for their potential use as Alzheimer{\textquoteright}s disease (AD) therapeutics. Dysfunctional interactions of metal ions, especially those of Cu, Zn, and Fe, with the amyloid-beta (A beta) peptide are hypothesised to play an important role in the aetiology of AD, and disruption of these aberrant metal-peptide interactions via chelation therapy holds considerable promise as a therapeutic strategy. Tetrahydrosalens such as H2L1-5 have a significant affinity for metal ions, and thus should be able to compete with the A beta peptide for Cu, Zn, and Fe in the brain. This activity was assayed in vitro via a turbidity assay; H2L1 and H2L3 were found to attenuate A beta(1-40) aggregation after exposure to Cu2+ and Zn2+. In addition, H2L1-5 were determined to be potent antioxidants on the basis of an in vitro antioxidant assay. GL(1-5) were prepared as metal binding prodrugs; glycosylation is intended to prevent systemic metal binding, improve solubility, and enhance brain uptake. Enzymatic (beta-glucosidase) deprotection of the carbohydrate moieties was facile, with the exception of GL(4), demonstrating the general feasibility of this prodrug approach. Finally, a representative prodrug, GL(3), was determined to be non-toxic over a large concentration range in a cell viability assay.}, keywords = {A-BETA, ACTIVITY, antioxidant, COMPLEXES, DISEASE, HYDROGEN-PEROXIDE, IN-VITRO, NEURODEGENERATIVE DISORDERS, OXIDATIVE STRESS, TRANSGENIC MICE, zinc}, isbn = {1477-9226}, url = {://000264978300018}, author = {Storr, T. and Scott, L. E. and Bowen, M. L. and Green, D. E. and Thompson, K. H. and Schugar, H. J. and Orvig, Chris} } @article {2369, title = {Long-chain rhenium and technetium glucosamine conjugates}, journal = {Dalton Transactions}, number = {42}, year = {2009}, note = {ISI Document Delivery No.: 508YBTimes Cited: 0Cited Reference Count: 44Bowen, Meryn L. Chen, Zhen-Feng Roos, Adrienne M. Misri, Ripen Haefeli, Urs Adam, Michael J. Orvig, Chris}, pages = {9228-9236}, type = {Article}, abstract = {A series of five glucosamine-conjugated organometallic complexes of the tricarbonyl cores of technetium-99m and rhenium were made. Glucosamine was derivatized at the C-2 nitrogen with long chain alkyl spacers linked to either pyridyl-tert-nitrogen-phenol tridentate chelates or cyclopentadienyl ligating groups. The metal complexes of the tridentate ligands were formed by refluxing with [Re(CO)(3)(H2O)(3)]Br, or with a base and [Tc-99m(CO)(3)(H2O)(3)](+). These ligands were found to be competent chelates in binding the [Tc-99m(CO)(3)](+) core as radiolabeling yields ranged from 87 to 93\% and the resulting complexes are stable to cysteine and histidine challenges for 24 h. The cyclopentadienyl analogues were formed using a double ligand transfer reaction for the rhenium complexes and a single ligand transfer for the technetium-99m complexes. All five rhenium complexes were tested as substrates of hexokinase; two of these complexes were tested as hexokinase inhibitors and they were found to be competent inhibitors, suggesting that they may be able to interact with hexokinase. MTT cytotoxicity studies were performed and the complexes tested were found to be non-toxic to the concentrations tested (100 mu M or 1 mM). GLUT-1 mediated cell uptake studies were performed on all five technetium-99m complexes, and their cell entry was found to parallel their lipophilicities, suggesting that cellular uptake is by passive diffusion and is not mediated by GLUT-1.}, keywords = {99M-TECHNETIUM, BIOMOLECULES, BREAST-CANCER, DERIVATIVES, HEXOKINASE, IN-VITRO, METAL-COMPLEXES, RE, TC-99M, TRANSPORT}, isbn = {1477-9226}, url = {://000270973800021}, author = {Bowen, M. L. and Chen, Z. F. and Roos, A. M. and Misri, R. and Hafeli, U. and Adam,Michael J. and Orvig, Chris} } @article {2369, title = {Long-chain rhenium and technetium glucosamine conjugates}, journal = {Dalton Transactions}, number = {42}, year = {2009}, note = {ISI Document Delivery No.: 508YBTimes Cited: 0Cited Reference Count: 44Bowen, Meryn L. Chen, Zhen-Feng Roos, Adrienne M. Misri, Ripen Haefeli, Urs Adam, Michael J. Orvig, Chris}, pages = {9228-9236}, type = {Article}, abstract = {A series of five glucosamine-conjugated organometallic complexes of the tricarbonyl cores of technetium-99m and rhenium were made. Glucosamine was derivatized at the C-2 nitrogen with long chain alkyl spacers linked to either pyridyl-tert-nitrogen-phenol tridentate chelates or cyclopentadienyl ligating groups. The metal complexes of the tridentate ligands were formed by refluxing with [Re(CO)(3)(H2O)(3)]Br, or with a base and [Tc-99m(CO)(3)(H2O)(3)](+). These ligands were found to be competent chelates in binding the [Tc-99m(CO)(3)](+) core as radiolabeling yields ranged from 87 to 93\% and the resulting complexes are stable to cysteine and histidine challenges for 24 h. The cyclopentadienyl analogues were formed using a double ligand transfer reaction for the rhenium complexes and a single ligand transfer for the technetium-99m complexes. All five rhenium complexes were tested as substrates of hexokinase; two of these complexes were tested as hexokinase inhibitors and they were found to be competent inhibitors, suggesting that they may be able to interact with hexokinase. MTT cytotoxicity studies were performed and the complexes tested were found to be non-toxic to the concentrations tested (100 mu M or 1 mM). GLUT-1 mediated cell uptake studies were performed on all five technetium-99m complexes, and their cell entry was found to parallel their lipophilicities, suggesting that cellular uptake is by passive diffusion and is not mediated by GLUT-1.}, keywords = {99M-TECHNETIUM, BIOMOLECULES, BREAST-CANCER, DERIVATIVES, HEXOKINASE, IN-VITRO, METAL-COMPLEXES, RE, TC-99M, TRANSPORT}, isbn = {1477-9226}, url = {://000270973800021}, author = {Bowen, M. L. and Chen, Z. F. and Roos, A. M. and Misri, R. and Hafeli, U. and Adam,Michael J. and Orvig, Chris} } @article {2388, title = {Potential new inorganic antitumour agents from combining the anticancer traditional Chinese medicine (TCM) liriodenine with metal ions, and DNA binding studies}, journal = {Dalton Transactions}, number = {2}, year = {2009}, note = {ISI Document Delivery No.: 385IHTimes Cited: 6Cited Reference Count: 68Chen, Zhen-Feng Liu, Yan-Cheng Liu, Li-Min Wang, Heng-Shan Qin, San-Hai Wang, Bo-Long Bian, He-Dong Yang, Bin Fun, Hoong-Kun Liu, Hua-Gang Liang, Hong Orvig, Chris}, pages = {262-272}, type = {Article}, abstract = {Liriodenine (L), an active component of the anticancer traditional Chinese medicine (TCM), was isolated from Zanthoxylum nitidum. Its reactions with Pt(II) and Ru(II) afforded three metal complexes: cis-[PtCl2(L)] (1), cis-[PtCl2(L)(DMSO)] (2), and cis-[RuCl2(L)(DMSO)(2)]center dot 1.5H(2)O (3), the crystal structures of L, 2 and 3 were determined by single-crystal X-ray diffraction methods. These complexes were fully characterized by elemental analysis, IR spectrophotometry, H-1 and C-13 NMR spectroscopies, and ES mass spectrometry. The in vitro cytotoxicity of L and complexes 1-3 against 11 human tumour cell lines was assayed. The metal-based compounds exhibit enhanced cytotoxicity vs. free L, suggesting that these compounds display synergy in the combination of metal ions and liriodenine. The binding properties of L and its complexes 1-3 to ct-DNA were investigated through UV-vis, fluorescence, CD spectra, viscosity and agarose gels electrophoretic measurements.}, keywords = {AFFINITY, ALKALOIDS, CISPLATIN, CYTOTOXIC ACTIVITY, DRUGS, FLUORESCENCE, IN-VITRO, PLATINUM(II) COMPLEXES, RUTHENIUM(II) COMPLEXES, TOPOISOMERASE-II}, isbn = {1477-9226}, url = {://000261807400006}, author = {Chen, Z. F. and Liu, Y. C. and Liu, L. M. and Wang, H. S. and Qin, S. H. and Wang, B. L. and Bian, H. D. and Yang, B. and Fun, H. K. and Liu, H. G. and Liang, H. and Orvig, Chris} } @article {2024, title = {99m-Technetium carbohydrate conjugates as potential agents in molecular imaging}, journal = {Chemical Communications}, number = {41}, year = {2008}, note = {ISI Document Delivery No.: 365LHTimes Cited: 19Cited Reference Count: 97Bowen, Meryn L. Orvig, Chris}, pages = {5077-5091}, type = {Article}, abstract = {This feature article covers recent reports of work towards the development of Tc-99m-carbohydrate based agents for use in SPECT imaging, particularly of cancerous tissue. An outline of some of the key biological functions and coordination chemistry of carbohydrates is given, along with an introduction to bioconjugation and molecular imaging. Technetium coordination chemistry and the subset of this involving bioconjugates are discussed before moving into the focus of the article: glycoconjugates of Tc-99m(v) and the more recently developed [Tc-99m(I)(CO)(3)](+). Significant work in the last decade has featured the very attractive [Tc-99m(CO)(3)](+) core, and the ligand sets designed for this core are discussed in detail.}, keywords = {ANTITUMOR-ACTIVITY, BIFUNCTIONAL CHELATORS, BIOLOGICAL EVALUATION, D-GLUCOSE, IN-VITRO, ISOSTRUCTURAL RE, METAL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TC-99M COMPLEXES, TRICARBONYL COMPLEXES}, isbn = {1359-7345}, url = {://000260407400002}, author = {Bowen, M. L. and Orvig, Chris} } @article {1428, title = {Blood compatibility of novel water soluble hyperbranched polyglycerol-based multivalent cationic polymers and their interaction with DNA}, journal = {Biomaterials}, volume = {27}, number = {31}, year = {2006}, note = {ISI Document Delivery No.: 085NOTimes Cited: 48Cited Reference Count: 41Kainthan, Rajesh Kumar Gnanamani, Muthiah Ganguli, Munia Ghosh, Tanay Brooks, Donald E. Maiti, Souvik Kizhakkedathu, Jayachandran N.}, month = {Nov}, pages = {5377-5390}, type = {Article}, abstract = {A novel class of hyperbranched polymers based on polyglycerol (PG) and poly(ethylene glycol) (PEG) are synthesized by multibranching anionic ring opening polymerization. Multivalent cationic sites are added to these polymers by a post-amination and quarternization reactions. Blood compatibility studies using these polymers at different concentrations showed insignificant effects on complement activation, platelet activation, coagulation, erythrocyte aggregation and hemolysis compared to branched cationic polyethyleneimine (PEI). The degree of quarternization does not have large influence on the blood compatibility of the new polymers. Cytotoxicity of these polymers is significantly lower than that of PEI and is a function of quarternized nitrogen present in the polymer. Also, these polymers bind DNA in the nanomolar range and are able to condense DNA to highly compact, stable, water soluble nanoparticles in the range of 60-80 nm. Gel electrophoresis studies showed that they form electroneutral complexes with DNA around N/P ratio 1 irrespective of the percentage of quarternization under the conditions studied. (c) 2006 Elsevier Ltd. All rights reserved.}, keywords = {AFM, blood-compatibility, cationic polymers, COAGULATION, COMPLEXES, delivery, DNA, drug, GENE DELIVERY, hyperbranched polymers, IN-VITRO, MOLECULAR-WEIGHT, NANOPARTICLES, OPPOSITELY CHARGED SURFACTANT, PLATELETS, RANDOM COPOLYMER, therapy}, isbn = {0142-9612}, url = {://000240611000005}, author = {Kainthan, R. K. and Gnanamani, M. and Ganguli, M. and Ghosh, T. and Brooks, D. E. and Maiti, S. and Kizhakkedathu, J. N.} } @article {1390, title = {Carbohydrate-appended 3-hydroxy-4-pyridinone complexes of the [M(CO)(3)](+) core (M) Re, Tc-99m, Re-186)}, journal = {Bioconjugate Chemistry}, volume = {17}, number = {5}, year = {2006}, note = {ISI Document Delivery No.: 085LXTimes Cited: 21Cited Reference Count: 69Ferreira, Cara L. Bayly, Simon R. Green, David E. Storr, Tim Barta, Cheri A. Steele, Jennifer Adam, Michael J. Orvig, Chris}, month = {Sep}, pages = {1321-1329}, type = {Article}, abstract = {This work describes the use of 3-hydroxy-4-pyridinone ligands for binding the [M(CO)(3)](+) core ( M) Re, Tc) in the context of preparing novel Tc( I) and Re( I) glucose conjugates. Five pyridinone ligands bearing pendent carbohydrate moieties, HL1-5, were coordinated to the [M(CO)(3)](+0) core on the macroscopic scale ( M) Re) and on the tracer scale (M) = Tc-99m, Re-186). On the macroscopic scale the complexes, ReL1-5(CO)(3)(H{\O}-2), were thoroughly characterized by mass spectrometry, IR spectroscopy, UV-visible spectroscopy, elemental analysis, and 1D/2D NMR spectroscopy. Characterization confirmed the bidentate coordination of the pyridinone and the pendent nature of the carbohydrate and suggests the presence of a water molecule in the sixth coordination site. In preliminary biological evaluation, both the ligands and complexes were assessed as potential substrates or inhibitors of hexokinase, but showed no activity. Labeling via the [Tc-99m(CO)(3)(H2O)(3)](+) precursor gave the tracer species (TcL1-5)-Tc-99m(CO)(3)(H2O) in high radiochemical yields. Similar high radiochemical yields when labeling with Re-186 were facilitated by in situ preparation of the [Re-186( CO)(3)(H2O)(3)](+) species in the presence of HL1-5 to give (ReL1-5)-Re-186(CO)(3)(H2O). Stability challenges, incubating (TcL1-5)-Tc-99m(CO)(3)(H2O) in the presence of excess cysteine and histidine, confirmed complex stability up to 24 h.}, keywords = {5-HT1A RECEPTOR, BIFUNCTIONAL LIGAND, BIOMOLECULES, GLUCOSE, IMAGING AGENTS, IN-VITRO, METAL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRICARBONYL COMPLEXES, TRIDENTATE LIGANDS}, isbn = {1043-1802}, url = {://000240606700027}, author = {Ferreira, C. L. and Bayly, S. R. and Green, D. E. and Storr, T. and Barta, C. A. and Steele, J. and Adam,Michael J. and Orvig, Chris} } @article {1390, title = {Carbohydrate-appended 3-hydroxy-4-pyridinone complexes of the [M(CO)(3)](+) core (M) Re, Tc-99m, Re-186)}, journal = {Bioconjugate Chemistry}, volume = {17}, number = {5}, year = {2006}, note = {ISI Document Delivery No.: 085LXTimes Cited: 21Cited Reference Count: 69Ferreira, Cara L. Bayly, Simon R. Green, David E. Storr, Tim Barta, Cheri A. Steele, Jennifer Adam, Michael J. Orvig, Chris}, month = {Sep}, pages = {1321-1329}, type = {Article}, abstract = {This work describes the use of 3-hydroxy-4-pyridinone ligands for binding the [M(CO)(3)](+) core ( M) Re, Tc) in the context of preparing novel Tc( I) and Re( I) glucose conjugates. Five pyridinone ligands bearing pendent carbohydrate moieties, HL1-5, were coordinated to the [M(CO)(3)](+0) core on the macroscopic scale ( M) Re) and on the tracer scale (M) = Tc-99m, Re-186). On the macroscopic scale the complexes, ReL1-5(CO)(3)(H{\O}-2), were thoroughly characterized by mass spectrometry, IR spectroscopy, UV-visible spectroscopy, elemental analysis, and 1D/2D NMR spectroscopy. Characterization confirmed the bidentate coordination of the pyridinone and the pendent nature of the carbohydrate and suggests the presence of a water molecule in the sixth coordination site. In preliminary biological evaluation, both the ligands and complexes were assessed as potential substrates or inhibitors of hexokinase, but showed no activity. Labeling via the [Tc-99m(CO)(3)(H2O)(3)](+) precursor gave the tracer species (TcL1-5)-Tc-99m(CO)(3)(H2O) in high radiochemical yields. Similar high radiochemical yields when labeling with Re-186 were facilitated by in situ preparation of the [Re-186( CO)(3)(H2O)(3)](+) species in the presence of HL1-5 to give (ReL1-5)-Re-186(CO)(3)(H2O). Stability challenges, incubating (TcL1-5)-Tc-99m(CO)(3)(H2O) in the presence of excess cysteine and histidine, confirmed complex stability up to 24 h.}, keywords = {5-HT1A RECEPTOR, BIFUNCTIONAL LIGAND, BIOMOLECULES, GLUCOSE, IMAGING AGENTS, IN-VITRO, METAL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRICARBONYL COMPLEXES, TRIDENTATE LIGANDS}, isbn = {1043-1802}, url = {://000240606700027}, author = {Ferreira, C. L. and Bayly, S. R. and Green, D. E. and Storr, T. and Barta, C. A. and Steele, J. and Adam,Michael J. and Orvig, Chris} } @article {1577, title = {Design of targeting ligands in medicinal inorganic chemistry}, journal = {Chemical Society Reviews}, volume = {35}, number = {6}, year = {2006}, note = {ISI Document Delivery No.: 047UHTimes Cited: 58Cited Reference Count: 51}, pages = {534-544}, type = {Review}, abstract = {This tutorial review will highlight recent advances in medicinal inorganic chemistry pertaining to the use of multifunctional ligands for enhanced effect. Ligands that adequately bind metal ions and also include specific targeting features are gaining in popularity due to their ability to enhance the efficacy of less complicated metal-based agents. Moving beyond the traditional view of ligands modifying reactivity, stabilizing specific oxidation states, and contributing to substitution inertness, we will discuss recent work involving metal complexes with multifunctional ligands that target specific tissues, membrane receptors, or endogenous molecules, including enzymes.}, keywords = {CANCER, COMPLEXES, FLUORESCENCE, GADOLINIUM, IN-VITRO, PARACEST AGENTS, PROTEINS, RECEPTOR, therapy, TRANSPORT}, isbn = {0306-0012}, url = {://000237903700005}, author = {Storr, T. and Thompson, K. H. and Orvig, Chris} } @article {1392, title = {Glucosamine conjugates of tricarbonylcyclopentadienyl rhenium(I) and technetium(I) cores}, journal = {Inorganic Chemistry}, volume = {45}, number = {17}, year = {2006}, note = {ISI Document Delivery No.: 073DPTimes Cited: 13Cited Reference Count: 43Ferreira, Cara L. Ewart, Charles B. Bayly, Simon R. Patrick, Brian O. Steele, Jennifer Adam, Michael J. Orvig, Chris}, month = {Aug}, pages = {6979-6987}, type = {Article}, abstract = {To obtain a Tc-99m glucose conjugate for imaging, double-ligand transfer (DLT) and related reactions were examined for the preparation of CpM(CO)(3) (Cp = cyclopentadienyl; M = Re, Tc) complexes with pendant carbohydrates at Cp. Tricarbonyl {N-(1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranose) cyclopentadienyl carboxamide} rhenium(I) (1a) and tricarbonyl {N-(2-amino-2-deoxy-beta-D-glucopyranose) cyclopentadienyl carboxamide} rhenium(I) (2a) were prepared. The compounds were fully characterized by mass spectrometry, elemental analysis, IR, and NMR spectroscopy. Full assignment of the NMR spectra verified the pendant nature of the glucosamine moieties in the solution state and that 2a exists as both anomers. The solid-state structure of 2a was determined by X-ray crystallography, again confirming the pendant nature of the glucosamine, but differing from the solution state in that the, anomer crystallized preferentially (93\%). Compound 2a was determined to be a high-affinity competitive inhibitor (K-i = 330 +/- 70 mu M) of the glucose metabolism enzyme hexokinase, demonstrating that it retains certain biological activity. The Tc-99m analogues 1b and 2b were prepared in moderate radiochemical yields by means of the single-ligand transfer (SLT) route, which is more pertinent to radiopharmaceutical synthesis.}, keywords = {BIOMOLECULES, COORDINATION, CYCLOPENTADIENYL-TRICARBONYL COMPLEXES, DERIVATIVES, FUNCTIONALIZATION, IN-VITRO, METAL-COMPLEXES, RE-186(I), RECEPTOR, TC-99M}, isbn = {0020-1669}, url = {://000239723300060}, author = {Ferreira, C. L. and Ewart, C. B. and Bayly, S. R. and Patrick, B. O. and Steele, J. and Adam,Michael J. and Orvig, Chris} } @article {1392, title = {Glucosamine conjugates of tricarbonylcyclopentadienyl rhenium(I) and technetium(I) cores}, journal = {Inorganic Chemistry}, volume = {45}, number = {17}, year = {2006}, note = {ISI Document Delivery No.: 073DPTimes Cited: 13Cited Reference Count: 43Ferreira, Cara L. Ewart, Charles B. Bayly, Simon R. Patrick, Brian O. Steele, Jennifer Adam, Michael J. Orvig, Chris}, month = {Aug}, pages = {6979-6987}, type = {Article}, abstract = {To obtain a Tc-99m glucose conjugate for imaging, double-ligand transfer (DLT) and related reactions were examined for the preparation of CpM(CO)(3) (Cp = cyclopentadienyl; M = Re, Tc) complexes with pendant carbohydrates at Cp. Tricarbonyl {N-(1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-beta-D-glucopyranose) cyclopentadienyl carboxamide} rhenium(I) (1a) and tricarbonyl {N-(2-amino-2-deoxy-beta-D-glucopyranose) cyclopentadienyl carboxamide} rhenium(I) (2a) were prepared. The compounds were fully characterized by mass spectrometry, elemental analysis, IR, and NMR spectroscopy. Full assignment of the NMR spectra verified the pendant nature of the glucosamine moieties in the solution state and that 2a exists as both anomers. The solid-state structure of 2a was determined by X-ray crystallography, again confirming the pendant nature of the glucosamine, but differing from the solution state in that the, anomer crystallized preferentially (93\%). Compound 2a was determined to be a high-affinity competitive inhibitor (K-i = 330 +/- 70 mu M) of the glucose metabolism enzyme hexokinase, demonstrating that it retains certain biological activity. The Tc-99m analogues 1b and 2b were prepared in moderate radiochemical yields by means of the single-ligand transfer (SLT) route, which is more pertinent to radiopharmaceutical synthesis.}, keywords = {BIOMOLECULES, COORDINATION, CYCLOPENTADIENYL-TRICARBONYL COMPLEXES, DERIVATIVES, FUNCTIONALIZATION, IN-VITRO, METAL-COMPLEXES, RE-186(I), RECEPTOR, TC-99M}, isbn = {0020-1669}, url = {://000239723300060}, author = {Ferreira, C. L. and Ewart, C. B. and Bayly, S. R. and Patrick, B. O. and Steele, J. and Adam,Michael J. and Orvig, Chris} } @article {1505, title = {Identification of sokotrasterol sulfate as a novel proangiogenic steroid}, journal = {Circulation Research}, volume = {99}, number = {3}, year = {2006}, note = {ISI Document Delivery No.: 070DTTimes Cited: 3Cited Reference Count: 39Murphy, Siun Larrivee, Bruno Pollet, Ingrid Craig, Kyle S. Williams, David E. Huang, Xin-Hui Abbott, Megan Wong, Fred Curtis, Cameron Conrads, Thomas P. Veenstra, Timothy Puri, Mira Hsiang, York Roberge, Michel Andersen, Raymond J. Karsan, Aly}, month = {Aug}, pages = {257-265}, type = {Article}, abstract = {The potential to promote neovascularization in ischemic tissues using exogenous agents has become an exciting area of therapeutics. In an attempt to identify novel small molecules with angiogenesis promoting activity, we screened a library of natural products and identified a sulfated steroid, sokotrasterol sulfate, that induces angiogenesis in vitro and in vivo. We show that sokotrasterol sulfate promotes endothelial sprouting in vitro, new blood vessel formation on the chick chorioallantoic membrane, and accelerates angiogenesis and reperfusion in a mouse hindlimb ischemia model. We demonstrate that sulfation of the steroid is critical for promoting angiogenesis, as the desulfated steroid exhibited no endothelial sprouting activity. We thus developed a chemically synthesized sokotrasterol sulfate analog, 2 beta,3 alpha,6 alpha-cholestanetrisulfate, that demonstrated equivalent activity in the hindlimb ischemia model and resulted in the generation of stable vessels that persisted following cessation of therapy. The function of sokotrasterol sulfate was dependent on cyclooxygenase-2 activity and vascular endothelial growth factor induction, as inhibition of either cyclooxygenase-2 or vascular endothelial growth factor blocked angiogenesis. Surface expression of alpha(v)beta(3) integrin was also necessary for function, as neutralization of alpha(v)beta(3) integrin, but not beta(1) integrin, binding abrogated endothelial sprouting and antiapoptotic activity in response to sokotrasterol sulfate. Our findings indicate that sokotrasterol sulfate and its analogs can promote angiogenesis in vitro and in vivo and could potentially be used for promoting neovascularization to relieve the sequelae of vasoocclusive diseases.}, keywords = {ACTIVATION, ANGIOGENESIS, apoptosis, ARTERIOGENESIS, ENDOTHELIAL-CELLS, endothelium, IN-VITRO, INHIBITION, INTEGRIN ALPHA(V)BETA(3), ischemia, MARINE NATURAL-PRODUCTS, NF-KAPPA-B}, isbn = {0009-7330}, url = {://000239501200009}, author = {Murphy, S. and Larrivee, B. and Pollet, I. and Craig, K. S. and Williams, D. E. and Huang, X. H. and Abbott, M. and Wong, F. and Curtis, C. and Conrads, T. P. and Veenstra, T. and Puri, M. and Hsiang, Y. and Roberge, M. and Andersen, R. J. and Karsan, A.} } @article {1267, title = {Carbohydrate-appended 2,2 {\textquoteright}-dipicolylamine metal complexes as potential imaging agents}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 44Cited Reference Count: 58}, month = {Apr}, pages = {2698-2705}, type = {Article}, abstract = {Three discrete carbohydrate-appended 2,2{\textquoteright}-dipicolylamine ligands were complexed to the {M(CO)3}(+) (M = Tc-99m/ Re) core: 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-D-glucopyranoside (L-1), 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-Dxylopyranoside (L-2), and 2-(bis(2-pyridinylmethyl)amino)ethyl-alpha-D-mannopyranoside (L-3). An ethylene spacer is used to separate the carbohydrate moiety and the dipicolylamine (DPA) function in all three ligands. The Re complexes [Re(L1-3)(CO)(3)]Br were characterized by H-1 and C-13 1D/2D NMR spectroscopies, which confirmed the pendant nature of the carbohydrate moieties in solution. NMR measurements also established the long-range asymmetric effect of the carbohydrate functions on the chelating portion of the ligand. One analogue, [Re(L-1)(CO)(3)]Cl, was characterized in the solid state by X-ray crystallography. Further characterization was provided by IR spectroscopy, elemental analysis, conductivity, and mass spectrometry. Radiolabeling of L-1-L-3 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded high yield compounds of identical character to the Re analogues. The radiolabeled compounds were found to be stable toward ligand exchange in the presence of a large excess of either cysteine or histidine over a 24-h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, BOMBESIN ANALOG, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, LIGANDS, PALLADIUM(II) COMPLEXES, RHENIUM CARBONYL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRIDENTATE}, isbn = {0020-1669}, url = {://000228374400020}, author = {Storr, T. and Sugai, Y. and Barta, C. A. and Mikata, Y. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1267, title = {Carbohydrate-appended 2,2 {\textquoteright}-dipicolylamine metal complexes as potential imaging agents}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 44Cited Reference Count: 58}, month = {Apr}, pages = {2698-2705}, type = {Article}, abstract = {Three discrete carbohydrate-appended 2,2{\textquoteright}-dipicolylamine ligands were complexed to the {M(CO)3}(+) (M = Tc-99m/ Re) core: 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-D-glucopyranoside (L-1), 2-(bis(2-pyridinylmethyl)amino)ethyl-beta-Dxylopyranoside (L-2), and 2-(bis(2-pyridinylmethyl)amino)ethyl-alpha-D-mannopyranoside (L-3). An ethylene spacer is used to separate the carbohydrate moiety and the dipicolylamine (DPA) function in all three ligands. The Re complexes [Re(L1-3)(CO)(3)]Br were characterized by H-1 and C-13 1D/2D NMR spectroscopies, which confirmed the pendant nature of the carbohydrate moieties in solution. NMR measurements also established the long-range asymmetric effect of the carbohydrate functions on the chelating portion of the ligand. One analogue, [Re(L-1)(CO)(3)]Cl, was characterized in the solid state by X-ray crystallography. Further characterization was provided by IR spectroscopy, elemental analysis, conductivity, and mass spectrometry. Radiolabeling of L-1-L-3 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded high yield compounds of identical character to the Re analogues. The radiolabeled compounds were found to be stable toward ligand exchange in the presence of a large excess of either cysteine or histidine over a 24-h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, BOMBESIN ANALOG, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, LIGANDS, PALLADIUM(II) COMPLEXES, RHENIUM CARBONYL-COMPLEXES, STRUCTURAL-CHARACTERIZATION, TRIDENTATE}, isbn = {0020-1669}, url = {://000228374400020}, author = {Storr, T. and Sugai, Y. and Barta, C. A. and Mikata, Y. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1266, title = {Novel carbohydrate-appended metal complexes for potential use in molecular imaging}, journal = {Chemistry-a European Journal}, volume = {11}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 887BZTimes Cited: 27Cited Reference Count: 60}, month = {Dec}, pages = {195-203}, type = {Article}, abstract = {Seven discrete sugar-pendant diamines were complexed to the {M(CO)(3)}(+) (Tc-99m/Re) core: 1,3-diamino-2-propyl beta-D-glucopyranoside (L-1), 1,3-diamino-2-propyl beta-D-xylopyranoside (L-2), 1,3-diamino-2-propyl alpha-D-mannopyranoside (L-3), 1,3-diamino-2-propyl alpha-D-galactopyranoside (L-4), 1,3diamino-2-propyl beta-D-galactopyranoside (L-5), 1,3-diamino-2-propyl beta-(alpha-D-glucopyranosyl-(1,4)-D-glucopyrano- side) (L-6), and bis(aminomethyl)bis[(beta-D-glucopyranosyloxy)methyl]methane (L-7). The Re complexes [Re((LL7)-L-1)(Br)(CO)(3)] were characterized by H-1 and C-13 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L-2)(CO)(3)Br] and [Re(L-3)(CO)(3)Br], were characterized in the solid state by X-ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H2O established that the complexes exist as [Re(L-1-L-7)- (H2O)(CO)(3)]Br in aqueous conditions. Radiolabelling of V-L 7 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, carbohydrates, CRYSTAL-STRUCTURES, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, molecular imaging, PALLADIUM(II) COMPLEXES, RADIOPHARMACEUTICALS, rhenium, STRUCTURAL-CHARACTERIZATION, SUGAR-PENDANT, TC-99M, technetium}, isbn = {0947-6539}, url = {://000226278700018}, author = {Storr, T. and Obata, M. and Fisher, C. L. and Bayly, S. R. and Green, D. E. and Brudzinska, I. and Mikata, Y. and Patrick, B. O. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1266, title = {Novel carbohydrate-appended metal complexes for potential use in molecular imaging}, journal = {Chemistry-a European Journal}, volume = {11}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 887BZTimes Cited: 27Cited Reference Count: 60}, month = {Dec}, pages = {195-203}, type = {Article}, abstract = {Seven discrete sugar-pendant diamines were complexed to the {M(CO)(3)}(+) (Tc-99m/Re) core: 1,3-diamino-2-propyl beta-D-glucopyranoside (L-1), 1,3-diamino-2-propyl beta-D-xylopyranoside (L-2), 1,3-diamino-2-propyl alpha-D-mannopyranoside (L-3), 1,3-diamino-2-propyl alpha-D-galactopyranoside (L-4), 1,3diamino-2-propyl beta-D-galactopyranoside (L-5), 1,3-diamino-2-propyl beta-(alpha-D-glucopyranosyl-(1,4)-D-glucopyrano- side) (L-6), and bis(aminomethyl)bis[(beta-D-glucopyranosyloxy)methyl]methane (L-7). The Re complexes [Re((LL7)-L-1)(Br)(CO)(3)] were characterized by H-1 and C-13 1D/2D NMR spectroscopy which confirmed the pendant nature of the carbohydrate moieties in solution. Additional characterization was provided by IR spectroscopy, elemental analysis, and mass spectrometry. Two analogues, [Re(L-2)(CO)(3)Br] and [Re(L-3)(CO)(3)Br], were characterized in the solid state by X-ray crystallography and represent the first reported structures of Re organometallic carbohydrate compounds. Conductivity measurements in H2O established that the complexes exist as [Re(L-1-L-7)- (H2O)(CO)(3)]Br in aqueous conditions. Radiolabelling of V-L 7 with [Tc-99m(H2O)(3)(CO)(3)](+) afforded in high yield compounds of identical character to the Re analogues. The radiolabelled compounds were determined to exhibit high in vitro stability towards ligand exchange in the presence of an excess of either cysteine or histidine over a 24 h period.}, keywords = {AMINO-SUGARS, ANTITUMOR-ACTIVITY, carbohydrates, CRYSTAL-STRUCTURES, D-GLUCOSE, HIGH-AFFINITY, IN-VITRO, molecular imaging, PALLADIUM(II) COMPLEXES, RADIOPHARMACEUTICALS, rhenium, STRUCTURAL-CHARACTERIZATION, SUGAR-PENDANT, TC-99M, technetium}, isbn = {0947-6539}, url = {://000226278700018}, author = {Storr, T. and Obata, M. and Fisher, C. L. and Bayly, S. R. and Green, D. E. and Brudzinska, I. and Mikata, Y. and Patrick, B. O. and Adam,Michael J. and Yano, S. and Orvig, Chris} } @article {1091, title = {The toxicity of trimethylarsine: an urban myth}, journal = {Journal of Environmental Monitoring}, volume = {7}, number = {1}, year = {2005}, note = {ISI Document Delivery No.: 896IBTimes Cited: 7Cited Reference Count: 50}, month = {Jan}, pages = {11-15}, type = {News Item}, keywords = {DISEASE, IN-VITRO, METHYLATION, MICE, STACHYBOTRYS-CHARTARUM}, isbn = {1464-0325}, url = {://000226926700007}, author = {Cullen, W. R. and Bentley, R.} } @article {1209, title = {Vanadium complexes with mixed O,S anionic ligands derived from maltol: Synthesis, characterization, and biological studies}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 32Cited Reference Count: 45}, month = {Apr}, pages = {2678-2688}, type = {Article}, 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- m ethyl-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-dimethyi-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) angstrom, V(2) = 0.664(2) angstrom]. 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.}, keywords = {BIOCHEMISTRY, BIS(MALTOLATO)OXOVANADIUM(IV), COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, EPR, IN-VITRO, METAL, OXOVANADIUM(IV)}, isbn = {0020-1669}, url = {://000228374400018}, author = {Monga, V. and Thompson, K. H. and Yuen, V. G. and Sharma, V. and Patrick, B. O. and McNeill, J. H. and Orvig, Chris} } @article {1209, title = {Vanadium complexes with mixed O,S anionic ligands derived from maltol: Synthesis, characterization, and biological studies}, journal = {Inorganic Chemistry}, volume = {44}, number = {8}, year = {2005}, note = {ISI Document Delivery No.: 916GWTimes Cited: 32Cited Reference Count: 45}, month = {Apr}, pages = {2678-2688}, type = {Article}, 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- m ethyl-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-dimethyi-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) angstrom, V(2) = 0.664(2) angstrom]. 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.}, keywords = {BIOCHEMISTRY, BIS(MALTOLATO)OXOVANADIUM(IV), COORDINATION CHEMISTRY, CRYSTAL-STRUCTURE, EPR, IN-VITRO, METAL, OXOVANADIUM(IV)}, isbn = {0020-1669}, url = {://000228374400018}, author = {Monga, V. and Thompson, K. H. and Yuen, V. G. and Sharma, V. and Patrick, B. O. and McNeill, J. H. and Orvig, Chris} } @article {797, title = {Do arsenosugars pose a risk to human health? The comparative toxicities of a trivalent and pentavalent arsenosugar}, journal = {Environmental Science \& Technology}, volume = {38}, number = {15}, year = {2004}, note = {ISI Document Delivery No.: 842WOTimes Cited: 23Cited Reference Count: 54}, month = {Aug}, pages = {4140-4148}, type = {Article}, abstract = {Seafood frequently contains high concentrations of arsenic (similar to10-100 mg/kg dry weight). In marine algae (seaweed), this arsenic occurs predominantly as ribose derivatives known collectively as arsenosugars. Although it is clear that arsenosugars are not acutely toxic, there is a possibility of arsenosugars having slight chronic toxicity. In general, trivalent arsenicals are more toxic than their pentavalent counterparts, so in this work we examine the hypothesis that trivalent arsenosugars might be significantly more toxic than pentavalent arsenosugars in vitro. We compared the in vitro toxicity of (R)-2,3-dihydroxypropyl-5-deoxy-5-dimethylarsinoyl-beta-D-riboside, a pentavalent arsenosugar, to that of its trivalent counterpart, (R)-2,3-dihydroxypropyl-5-deoxy-5-dimethylarsino-beta-D- riboside. The trivalent arsenosugar nicked plasmid DNA, whereas the pentavalent arsenosugar did not. The trivalent arsenosugar was more cytotoxic (IC50 = 200 muM, 48 h exposure) than its pentavalent counterpart (IC50 > 6000 muM, 48 h exposure) in normal human epidermal keratinocytes in vitro as determined via the neutral red uptake assay. However, both the trivalent and the pentavalent arsenosugars were significantly less toxic than MMA(III), DMA(III), and arsenate. Neither the pentavalent arsenosugar nor the trivalent arsenosugar were mutagenic in Salmonella TA104. The trivalent arsenosugar was readily formed by reaction of the pentavalent arsenosugar with thiol compounds, including, cysteine, glutathione, and dithioerythritol. This work suggests that the reduction of pentavalent arsenosugars to trivalent arsenosugars in biology might have environmental consequences, especially because seaweed consumption is a significant environmental source for human exposure to arsenicals.}, keywords = {DIMETHYLARSINIC ACID, DNA-DAMAGE, HUMAN-CELLS, IN-VITRO, INORGANIC ARSENICS, METABOLISM, METHYLATED ARSENICALS, MONOMETHYLARSONOUS ACID MMA(III), ORGANIC ARSENIC COMPOUNDS, SEAWEED}, isbn = {0013-936X}, url = {://000223035400022}, author = {Andrewes, P. and Demarini, D. M. and Funasaka, K. and Wallace, K. and Lai, V. W. M. and Sun, H. S. and Cullen, W. R. and Kitchin, K. T.} } @article {757, title = {Preparation and characterization of vanadyl complexes with bidentate maltol-type ligands; in vivo comparisons of anti-diabetic therapeutic potential}, journal = {Journal of Biological Inorganic Chemistry}, volume = {8}, number = {1-2}, year = {2003}, note = {ISI Document Delivery No.: 638ACTimes Cited: 62Cited Reference Count: 52}, month = {Jan}, pages = {66-74}, type = {Article}, abstract = {A series of 2-alkyl-3-hydroxy-4-pyrone oxovanadium(IV) compounds has been synthesized, characterized, and tested for bioactivity as potential insulin-enhancing agents. The vanadyl complexes, bis(maltolato)oxovanadium(IV), BMOV, bis(ethylmaltolato)oxovanadium(IV), BEOV, and bis(isopropylmaltolato) oxovanadium(IV), BIOV, were compared against vanadyl sulfate for glucose-lowering ability, when administered i.p. to STZ-diabetic rats, at a one-time dose of 0.1 mmol kg(-1) body weight. Blood levels of vanadium were determined at regular intervals, to 72 h, following i.p. injection. All complexes tested exceeded vanadyl sulfate in glucose-lowering ability; this effect was not correlated, however, with blood vanadium levels. Analysis of the pharmacokinetics of the disappearance of [ethyl-1-C-14]BEOV after an oral gavage dose (50 mg kg(-1), 0.144 mmol kg(-1), in a 10 mL kg(-1) volume of 1\% CMC solution) indicated clearly that metal ion-ligand dissociation took place relatively soon after oral ingestion of the complex. Half-lives of fast phase uptake and slow phase disappearance for C-14 and V were calculated from a two-compartment model for whole blood, plasma, liver, kidney, bone, small intestine, and lung, ranging from 17 min (t(1/2)alpha for C-14, liver) to 30 days (t(1/2)beta for V, bone). Curves of disappearance of plasma and whole blood C-14 and V diverged dramatically within the first hour after administration of the vanadium complex.}, keywords = {ABSORPTION, BIS(MALTOLATO)OXOVANADIUM(IV) BMOV, CHEMISTRY, COORDINATION MODE, ETHYL MALTOL, IN-VITRO, INSULIN MIMETIC AGENT, insulin-enhancing activity, pharmacokinetics, PHOSPHATIDYLINOSITOL 3-KINASE, POLYMORPHIC FORMS, RATS, STZ-diabetic rat, vanadyl pyrone complexes}, isbn = {0949-8257}, url = {://000180545000008}, author = {Thompson, K. H. and Liboiron, B. D. and Bellman, Yskdd and Setyawati, I. A. and Patrick, B. O. and Karunaratne, V. and Rawji, G. and Wheeler, J. and Sutton, K. and Bhanot, S. and Cassidy, C. and McNeill, J. H. and Yuen, V. G. and Orvig, Chris} } @article {774, title = {Ruthenium(II) sulfoxide-maltolato and -nitroimidazole complexes: Synthesis and MTT assay}, journal = {Inorganic Chemistry}, volume = {42}, number = {23}, year = {2003}, note = {ISI Document Delivery No.: 743FZTimes Cited: 14Cited Reference Count: 52}, month = {Nov}, pages = {7579-7586}, type = {Article}, abstract = {{Ru-II sulfoxide-maltolato complexes, Ru(ma)(2)(L)(2) (L = DMSO (1a) and TMSO (1b) or L-2 = BESE (1c)), were synthesized, as well as the analogous ethylmaltolato derivatives, Ru(etma)(2)(L)(2) (2a-c) (ma = 3-hydroxy-2-methylpyran-4-onate}, keywords = {CISPLATIN, CRYSTAL-STRUCTURE, EXPERIMENTAL-TUMORS, IN-VITRO, MOLECULAR-STRUCTURE, NAMI-A, RADIOSENSITIZING ACTIVITY, RAY STRUCTURAL CHARACTERIZATION, SOLUTION CHEMISTRY, SULFOXIDE)RUTHENIUM(II)}, isbn = {0020-1669}, url = {://000186562900037}, author = {Wu, A. and Kennedy, David C and Patrick, B. O. and James, Brian R.} } @article {499, title = {Effects of diabetes, vanadium, and insulin on glycogen synthase activation in Wistar rats}, journal = {Molecular and Cellular Biochemistry}, volume = {231}, number = {1-2}, year = {2002}, note = {ISI Document Delivery No.: 527LATimes Cited: 21Cited Reference Count: 51}, month = {Feb}, pages = {23-35}, type = {Article}, abstract = {In vivo effects of insulin and vanadium treatment on glycogen synthase (GS), glycogen synthase kinase-3 (GSK-3) and protein phosphatase-1 (PP1) activity were determined in Wistar rats with streptozotocin (STZ)-induced diabetes. The skeletal muscle was freeze-clamped before or following an insulin injection (5 U/kg i.v.). Diabetes, vanadium, and insulin in vivo treatment did not affect muscle GSK-3beta activity as compared to controls. Following insulin stimulation in 4-week STZ-diabetic rats muscle GS fractional activity (GSFA) was increased 3 fold (p < 0.05), while in 7-week diabetic rats it remained unchanged, suggesting development of insulin resistance in longer term diabetes. Muscle PP1 activity was increased in diabetic rats and returned to normal after vanadium treatment, while muscle GSFA remained unchanged. Therefore, it is possible that PP1 is involved in the regulation of some other cellular events of vanadium (other than regulation of glycogen synthesis). The lack of effect of vanadium treatment in stimulating glycogen synthesis in skeletal muscle suggests the involvement of other metabolic pathways in the observed glucoregulatory effect of vanadium.}, keywords = {BLOOD-GLUCOSE, GLUCOSE-TRANSPORT, glycogen, IN-VITRO, insulin resistance, MELLITUS, MOLECULAR MECHANISM, PHOSPHORYLATION, PROTEIN-KINASE-B, RABBIT SKELETAL-MUSCLE, S6 KINASE, serine/threonine kinases and phosphatases, streptozotocin-induced diabetes, SYNTHESIS, VANADATE}, isbn = {0300-8177}, url = {://000174186500004}, author = {Semiz, S. and Orvig, Chris and McNeill, J. H.} } @article {524, title = {Influence of chelation and oxidation state on vanadium bioavailability, and their effects on tissue concentrations of zinc, copper, and iron}, journal = {Biological Trace Element Research}, volume = {86}, number = {1}, year = {2002}, note = {ISI Document Delivery No.: 541ZTTimes Cited: 27Cited Reference Count: 45}, month = {Apr}, pages = {31-44}, type = {Article}, abstract = {Today, vanadium compounds are frequently included in nutritional supplements and are also being developed for therapeutic use in diabetes mellitus. Previously, tissue uptake of vanadium from bis(maltolato)oxovanadium(IV) (BMOV) was shown to be increased compared to its uptake from vanadyl sulfate (VS). Our primary objective was to test the hypothesis that complexation increases vanadium uptake and that this effect is independent of oxidation state. A secondary objective was to compare the effects of vanadium complexation and oxidation state on tissue iron, copper, and zinc. Wistar rats were fed either ammonium metavanadate (AMV), VS, or BMOV (1.2 mM each in the drinking water). Tissue uptake of V following 12 wk of BMOV or AMV was higher than that from VS (p < 0.05). BMOV led to decreased tissue Zn and increased bone Fe content. The same three compounds were compared in a cellular model of absorption (Caco-2 cells). Vanadium uptake from VS was higher than that from BMOV or AMV at 10 min, but from BMOV (250 \μM only, 60 min), uptake was far greater than from AMV or VS. These results show that neither complexation nor oxidation state alone are adequate predictors of relative absorption, tissue accumulation, or trace element interactions.}, keywords = {ABSORPTION, BIS(MALTOLATO)OXOVANADIUM(IV), bone, CACO-2, Caco-2 cells, COMPLEXES, DIABETIC RATS, GLUCOSE-METABOLISM, IN-VITRO, INSULIN, kidney, ORTHO-VANADATE, skeletal muscle, SULFATE, VANADIUM, zinc}, isbn = {0163-4984}, url = {://000175018100004}, author = {Thompson, K. H. and Tsukada, Y. and Xu, Z. M. and Battell, M. and McNeill, J. H. and Orvig, Chris} } @article {4873, title = {Zinc-bundle structure of the essential RNA polymerase subunit RPB10 from Methanobacterium thermoautotrophicum}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {97}, number = {12}, year = {2000}, note = {ISI Document Delivery No.: 322UATimes Cited: 14Cited Reference Count: 34}, month = {Jun}, pages = {6316-6321}, type = {Article}, abstract = {The RNA polymerase subunit RPB10 displays a high level of conservation across archaea and eukarya and is required for cell viability in yeast, Structure determination of this RNA polymerase subunit from Methanobacterium thermoautotrophicum reveals a topology, which we term a zinc-bundle, consisting of three cu-helices stabilized by a zinc ion. The metal ion is bound within an atypical CX2CXnCC sequence motif and serves to bridge an N-terminal loop with helix 3, This represents an example of two adjacent zinc-binding Cys residues within an alpha-helix conformation. Conserved surface features of RPB10 include discrete regions of neutral, acidic, and basic residues, the latter being located around the zinc-binding site. One or more of these regions may contribute to the role of this subunit as a scaffold protein within the polymerase holoenzyme.}, keywords = {ABC10-BETA, ARCHAEA, COMMON SUBUNITS, DOMAIN, genomics, IN-VITRO, PROTEINS, RESOLUTION, SEQUENCE, transcription}, isbn = {0027-8424}, url = {://000087526300018}, author = {Mackereth, C. D. and Arrowsmith, C. H. and Edwards, A. M. and McIntosh, L. P.} } @article {4711, title = {Enzymatic methylation of arsenic compounds. VII. Monomethylarsonous acid (MMA(III)) is the substrate for MMA methyltransferase of rabbit liver and human hepatocytes}, journal = {Toxicology and Applied Pharmacology}, volume = {158}, number = {1}, year = {1999}, note = {ISI Document Delivery No.: 216QCTimes Cited: 80Cited Reference Count: 33}, month = {Jul}, pages = {9-15}, type = {Article}, abstract = {Inorganic arsenite is methylated by some, but not all, animal species to dimethylarsinic acid (DMA), The monomethyl compound containing arsenic in an oxidation state of +3 has been proposed as an intermediate. Using highly purified arsenic methyltransferase from rabbit liver and the partially purified enzyme from Chang human liver hepatocytes, the activity of methylarsonic acid (MMA(V)) and methylarsonous acid (MMA(III)) as a substrate has been characterized by Michaelis-Menten kinetics. The rabbit liver enzyme has a greater affinity for MMA(III) (K-m = 0.92 x 10(-5) M) than MMA(V) (K-m = 7.0 x 10(-5) M) since the smaller the K, the greater the affinity. In addition, a dithiol, reduced lipoic acid or dithiothreitol, appears to be more active than GSH in satisfying the thiol requirement of the enzyme. Although investigators have been unable to detect the arsenic methyltransferase in surgically removed human liver, its presence in Chang human hepatocytes now has been established. The K-m for MMA(III), 3.04 x 10(-6), using MMAIII methyltransferase from Chang human hepatocytes was not greatly different from that of the rabbit liver enzyme, (C) 1999 Academic Press.}, keywords = {BINDING, CYTOSOL, IN-VITRO, INVITRO, METABOLISM, TOXICITY, WATER, WEST-BENGAL}, isbn = {0041-008X}, url = {://000081452500002}, author = {Zakharyan, R. A. and Ayala-Fierro, F. and Cullen, W. R. and Carter, D. M. and Aposhian, H. V.} } @article {4673, title = {Metabolism of arsenic in primary cultures of human and rat hepatocytes}, journal = {Chemical Research in Toxicology}, volume = {12}, number = {7}, year = {1999}, note = {ISI Document Delivery No.: 219JCTimes Cited: 81Cited Reference Count: 26}, month = {Jul}, pages = {560-565}, type = {Article}, abstract = {The liver is considered a major site for methylation of inorganic arsenic (iAs). However, there is Little data on the capacity of human liver to methylate iAs. This work examined the metabolism of arsenite (iAs(III)), arsenate (iAs(v)), methylarsine oxide ((MAsO)-O-III), methylarsonic acid (MAsv), dimethylarsinous acid (DMAsIII), and dimethylarsinic acid (DMAsV) in primary cultures of normal human hepatocytes. Primary rat hepatocytes were used as methylating controls, iAs(III) and (MAsO)-O-III were metabolized more extensively than iAs(v) and MAsv by either cell type. Neither human nor rat hepatocytes metabolized DMAsIII or DMAsV. Methylation of iAs(III) by human hepatocytes yielded methylarsenic (MAs) and dimethylarsenic (DMAs) species; (MAsO)-O-III was converted to DMAs. The total methylation yield (MAs and DMAs) increased over the range of 0.1 to 4 mu M iAs(III). However, DMAs production was inhibited by iAs(III) in a concentration-dependent manner, and the DMAs/MAs ratio decreased. iAs(III) (10 and 20 mu M) inhibited both methylation reactions. Inhibition of DMAs synthesis resulted in accumulation of iAs and MAs in human hepatocytes, suggesting that dimethylation is required for iAs clearance from cells. Methylation capacities of human hepatocytes obtained from four donors ranged from 3.1 to 35.7 pmol of iAs(III) per 10(6) cells per hour and were substantially lower than the methylation capacity of rat hepatocytes (387 pmol of iAs(III) per 10(6) cells per hour). The maximal methylation rates for either rat or human hepatocytes were attained between 0.4 and 4 mu M iAs(III). In summary, (i) human hepatocytes methylate iAs, (ii) the capacities for iAs methylation vary among individuals and are saturable, and (iii) moderate concentrations of iAs inhibit DMAs synthesis, resulting in an accumulation of iAs and MAs in cells.}, keywords = {ASSAY, ENZYMATIC METHYLATION, IN-VITRO, INGESTION, LIVER, PURIFICATION, TOXICITY, URINARY-EXCRETION}, isbn = {0893-228X}, url = {://000081603300003}, author = {Styblo, M. and Del Razo, L. M. and LeCluyse, E. L. and Hamilton, G. A. and Wang, C. Q. and Cullen, W. R. and Thomas, D. J.} }