@article {2512, title = {Ab Initio Studies of Vacancy-Defected Fullerenes and Single-Walled Carbon Nanotubes}, journal = {Int. J. Quantum Chem.}, volume = {109}, number = {14}, year = {2009}, note = {ISI Document Delivery No.: 507VUTimes Cited: 1Cited Reference Count: 51Liu, Lei Vincent Tian, Wei Quan Wang, Yan Alexander6th Congress of the International-Society-for-Theoretical-Chemical-PhysicsJUL 19-24, 2008Vancouver, CANADAInt Soc Theoret Chem PhysSp. Iss. SI}, month = {Nov}, pages = {3441-3456}, type = {Proceedings Paper}, abstract = {

The structures, stabilities, and electronic properties of the single-vacancy-defected fullerenes, C-60 and C-70, and the single- and double-vacancy-defected single-walled carbon nanotubes (SWCNTs) were studied within density functional theory. The isomerization barriers for the single-vacancy-defected C,, on the triplet potential energy surface (PES) are lower than those on the singlet PES. The symmetric double-vacancy-defected (10,0) SWCNT is the most stable one among the models investigated. According to the analyses of frontier molecular orbitals (FMOs), nature bond orbitals, and local density of states, introduction of vacancy on the SWCNT decreases the band gap of semiconducting SWCNT, increases the band gap of conducting SWCNT, destructs the pi conjugation of the FMOs, and gives rise to enhanced chemical activity. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 3441-3456, 2009

}, keywords = {BUCKMINSTERFULLERENE, C-60, COMPUTATIONS, CONDUCTANCE, density, EXCHANGE, FULLERENE, GENERALIZED GRADIENT APPROXIMATION, GROWTH, INHIBITION, OXIDES, single-walled carbon nanotube, vacancy defect}, isbn = {0020-7608}, url = {://000270884200026}, author = {Liu, L. V. and Tian, W. Q. and Y. A. Wang*} } @article {2513, title = {Divalent later transition metal complexes of the traditional chinese medicine (TCM) liriodenine: coordination chemistry, cytotoxicity and DNA binding studies}, journal = {Dalton Transactions}, number = {48}, year = {2009}, note = {ISI Document Delivery No.: 527IETimes Cited: 1Cited Reference Count: 91Liu, Yan-Cheng Chen, Zhen-Feng Liu, Li-Min Peng, Yan Hong, Xue Yang, Bin Liu, Hua-Gang Liang, Hong Orvig, Chris}, pages = {10813-10823}, type = {Article}, abstract = {Liriodenine (L), a natural alkaloid, was isolated as an active component from the anticancer traditional Chinese medicine (TCM), Zanthoxylum nitidum. It reacted with Mn-II, Fe-II, Co-II and Zn-II to afford four metal complexes: [MnCl2(L)(2)] (1), [FeCl2(L)(2)] (2), [Co(L)(2)(H2O)(2)center dot Co(L)(2)(CH3CH2OH)(2)](ClO4)(4) (3), and [Zn-2(L)(2)(mu(2)-Cl)(2)Cl-2] (4), which were characterized by elemental analysis, IR, ESI-MS. Their crystal structures were determined by the single crystal X-ray diffraction method. The in vitro cytotoxicity of L and complexes 1-4 against 10 human tumour cell lines was assayed. Some of these metal-based compounds exhibited enhanced cytotoxicity vs. free L to selected tumour cell lines. The binding properties of L and its complexes 1-4 to ct-DNA were investigated by spectroscopic methods and viscosity measurements. Agarose gel electrophoresis experiments were also carried out to evaluate their unwinding ability towards plasmid DNA and their inhibition towards Topoisomerase I. All the results indicate that complexes 1-4 may bind more intensively to the DNA helix than does L, and intercalative binding for complexes 1-4 and electrostatic interactions for complexes 3-4 to DNA should be considered. For complex 4, covalent binding to DNA may exist. Of special note, all these metal complexes effectively inhibit Topoisomerase I even at low concentration (<= 10 mu M).}, keywords = {antitumor agents, CISPLATIN, CRYSTAL-STRUCTURE, GEL-ELECTROPHORESIS, INHIBITION, INNOVATIVE COMBINATION, INTERCALATION, PLATINUM ANTICANCER AGENTS, RUTHENIUM(II) COMPLEXES, TOPOISOMERASE-I}, isbn = {1477-9226}, url = {://000272359900023}, author = {Liu, Y. C. and Chen, Z. F. and Liu, L. M. and Peng, Y. and Hong, X. and Yang, B. and Liu, H. G. and Liang, H. and Orvig, Chris} } @article {2092, title = {Mechanistic Studies on N-Acetylmuramic Acid 6-Phosphate Hydrolase (MurQ): An Etherase Involved in Peptidoglycan Recycling}, journal = {Biochemistry}, volume = {47}, number = {44}, year = {2008}, note = {ISI Document Delivery No.: 366TUTimes Cited: 4Cited Reference Count: 37Hadi, Timin Dahl, Ulrike Mayer, Christoph Tanner, Martin E.}, month = {Nov}, pages = {11547-11558}, type = {Article}, abstract = {Peptidoglycan recycling is a process in which bacteria import cell wall degradation products and incorporate them back into either peptidoglycan biosynthesis or basic metabolic pathways. The enzyme MurQ is an N-acetylmuramic acid 6-phosphate (MurNAc 6-phosphate) hydrolase (or etherase) that hydrolyzes the lactyl side chain from MurNAc 6-phosphate and generates GlcNAc 6-phosphate. This study supports a mechanism involving the syn elimination of lactate to give an alpha,beta-unsaturated aldehyde with (E)-stereochemistry, followed by the syn addition of water to give product. The observation of both a kinetic isotope effect slowing the reaction of [2-H-2]MurNAc 6-phosphate and the incorporation of solvent-derived deuterium into C2 of the product indicates that the C2-H bond is cleaved during catalysis. The observation that the solvent-derived 180 isotope is incorporated into the C3 position of the product, but not the C1 position, provides evidence of the cleavage of the C3-O bond and argues against imine formation. The finding that 3-chloro-3-deoxy-GlcNAc 6-phosphate serves as an alternate substrate is also consistent with an elimination-addition mechanism. Upon extended incubations of MurQ with GlcNAc 6-phosphate, the alpha,beta-unsaturated aldehydic intermediate accumulates in solution, and H-1 NMR analysis indicates it exists as the ring-closed form of the (E)-alkene. A structural model is developed for the Escherichia coli MurQ and is compared to that of the structural homologue glucosamine-6-phosphate synthase. Putative active site acid/base residues are probed by mutagenesis, and Glu83 and Glu114 are found to be crucial for catalysis. The Glu83Ala mutant is essentially inactive as an etherase yet is capable of exchanging the C2 proton of substrate with solvent-derived deuterium. This suggests that Glu83 may function as the acidic residue that protonates the departing lactate.}, keywords = {CATALYSIS, CELL-WALL, COLI GLUCOSAMINE-6-PHOSPHATE SYNTHASE, DERIVATIVES, ELIMINATION, ENOYL-COA HYDRATASE, ENVIRONMENT, ESCHERICHIA-COLI, INHIBITION, PHOSPHATE}, isbn = {0006-2960}, url = {://000260507100019}, author = {Hadi, T. and Dahl, U. and Mayer, C. and Tanner, M. E.} } @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.} } @inbook {1104, title = {Catalytic hydrogenation and hydrogenolysis of lignin model compounds using in-situ, water-soluble Ru/P(CH2OH)(3) systems}, booktitle = {Catalysis of Organic Reactions}, series = {Chemical Industries : A Series of Reference Books and Textbooks}, volume = {104}, year = {2005}, note = {ISI Document Delivery No.: BCH39Times Cited: 7Cited Reference Count: 32Proceedings Paper20th Conference on Catalysis of Organic ReactionsMAR 21-25, 2004Hilton Head Isl, SCOrgan React Catalysis Soc, WR GraceDavison, Parr Instrument, N Amer Catalysis Soc, ACS PRF, Engelhard, Degussa, AMC PMC, Merck \& Co, Eli Lilly \& Co, CRI Catalysts, Catalyst Grp, Umicore, Sud Chemie, Nova Mol Technologies Inc, Rohm \& Haas6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA}, pages = {135-143}, publisher = {Crc Press-Taylor \& Francis Group}, organization = {Crc Press-Taylor \& Francis Group}, address = {Boca Raton}, abstract = {Chemical modification of lignin without degradation of its polymeric structure could lower the production cost of higher quality paper, particularly with regard to stabilization toward light-induced yellowing, where the presence of so-called alpha-carbonyls and alpha-hydroxyl groups is of key importance. In order to explore which chromophore groups can be modified, hydrogenation of aromatic lignin model compounds has been tested, using as catalysts in-situ, water-soluble ruthenium species containing tris(hydroxymethyl)phosphine, P(CH2OH)(3). Such systems are active for hydrogenation of activated alkenes, carbonyl groups and, of more interest, hydrogenolysis of some aromatic alcohols. Catalyst activity depends on the phosphine/Ru ratio, the nature of the substrate (particularly substituents of the aromatic ring), and the solvents used. Thus, hydrogenation of a > C=O functionality can give either > CH(OH) or > CH2 depending on the nature of the arene fragment.}, keywords = {COMPLEXES, INHIBITION, mechanical pulps, MILD CONDITIONS}, isbn = {0-8247-2729-0}, url = {://000229314000016}, author = {Ezhova, M. B. and Lu, A. Z. and James, Brian R. and Hu, Thomas Q.}, editor = {Sowa, J. R.} } @inbook {1104, title = {Catalytic hydrogenation and hydrogenolysis of lignin model compounds using in-situ, water-soluble Ru/P(CH2OH)(3) systems}, booktitle = {Catalysis of Organic Reactions}, series = {Chemical Industries : A Series of Reference Books and Textbooks}, volume = {104}, year = {2005}, note = {ISI Document Delivery No.: BCH39Times Cited: 7Cited Reference Count: 32Proceedings Paper20th Conference on Catalysis of Organic ReactionsMAR 21-25, 2004Hilton Head Isl, SCOrgan React Catalysis Soc, WR GraceDavison, Parr Instrument, N Amer Catalysis Soc, ACS PRF, Engelhard, Degussa, AMC PMC, Merck \& Co, Eli Lilly \& Co, CRI Catalysts, Catalyst Grp, Umicore, Sud Chemie, Nova Mol Technologies Inc, Rohm \& Haas6000 BROKEN SOUND PARKWAY NW, STE 300, BOCA RATON, FL 33487-2742 USA}, pages = {135-143}, publisher = {Crc Press-Taylor \& Francis Group}, organization = {Crc Press-Taylor \& Francis Group}, address = {Boca Raton}, abstract = {Chemical modification of lignin without degradation of its polymeric structure could lower the production cost of higher quality paper, particularly with regard to stabilization toward light-induced yellowing, where the presence of so-called alpha-carbonyls and alpha-hydroxyl groups is of key importance. In order to explore which chromophore groups can be modified, hydrogenation of aromatic lignin model compounds has been tested, using as catalysts in-situ, water-soluble ruthenium species containing tris(hydroxymethyl)phosphine, P(CH2OH)(3). Such systems are active for hydrogenation of activated alkenes, carbonyl groups and, of more interest, hydrogenolysis of some aromatic alcohols. Catalyst activity depends on the phosphine/Ru ratio, the nature of the substrate (particularly substituents of the aromatic ring), and the solvents used. Thus, hydrogenation of a > C=O functionality can give either > CH(OH) or > CH2 depending on the nature of the arene fragment.}, keywords = {COMPLEXES, INHIBITION, mechanical pulps, MILD CONDITIONS}, isbn = {0-8247-2729-0}, url = {://000229314000016}, author = {Ezhova, M. B. and Lu, A. Z. and James, Brian R. and Hu, Thomas Q.}, editor = {Sowa, J. R.} } @article {1271, title = {Modulation of the G(2) cell cycle checkpoint by sesquiterpene lactones psilostachyins A and C isolated from the common ragweed Ambrosia artemisiifolia}, journal = {Planta Medica}, volume = {71}, number = {10}, year = {2005}, note = {ISI Document Delivery No.: 985TLTimes Cited: 8Cited Reference Count: 30}, month = {Oct}, pages = {938-943}, type = {Article}, abstract = {A phenotypic cell-based assay for inhibitors of the G(2) DNA damage checkpoint was used to screen plant extracts from the US National Cancer Institute Natural Products Repository. It revealed activity in a methanol extract from the common ragweed Ambrosia artemisiifolia. Assay-guided fractionation led to the identification of the sesquiterpene lactones psilostachyins A and C as novel checkpoint inhibitors. Elimination of their alpha,beta-unsaturated carbonyl group caused a loss of activity, suggesting that the compounds can bind covalently to target proteins through Michael addition. Psilostachyins A and C also blocked cells in mitosis and caused the formation of aberrant microtubule spindles. However, the compounds did not interfere with microtubule polymerization in vitro. The related sesquiterpene lactones psilostachyin 13, paulitin and isopaulitin were also isolated from the same extract but showed no checkpoint inhibition. The identification of the target(s) of psilostachyins A and C may provide further insight into the signalling pathways involved in cell cycle arrest and mitotic progression.}, keywords = {Ambrosia artemisiffolia, CAFFEINE, CANCER, cell cycle, checkpoint, CHK1, DILACTONE, DNA-DAMAGE CHECKPOINT, G(2) phase, INHIBITION, KINASE, MCF-7 CELLS, mitosis, P53, PROTEIN, UCN-01}, isbn = {0032-0943}, url = {://000233401400009}, author = {Sturgeon, C. M. and Craig, K. and Brown, C. and Rundle, N. T. and Andersen, R. J. and Roberge, M.} } @article {668, title = {Latonduines A and B, new alkaloids isolated from the marine sponge Stylissa carteri: Structure elucidation, synthesis, and biogenetic implications}, journal = {Organic Letters}, volume = {5}, number = {15}, year = {2003}, note = {ISI Document Delivery No.: 703AJTimes Cited: 17Cited Reference Count: 18}, month = {Jul}, pages = {2735-2738}, type = {Article}, abstract = {Latonduines A (6) and B (7), two new alkaloids with unprecedented heterocyclic skeletons, have been isolated from the Indonesian marine sponge Stylissa carted. The structures of the, latonduines were elucidated by analysis of spectroscopic data and confirmed by the total synthesis of latonduine A (6). It is proposed that ornithine is the biogenetic precursor to the aminopyrimidine fragment of the latonduines.}, keywords = {COMPOUND, DEBROMOHYMENIALDISINE, HYMENIALDISINE, INHIBITION, STEVENSINE}, isbn = {1523-7060}, url = {://000184257600039}, author = {Linington, R. G. and Williams, D. E. and Tahir, A. and Van Soest, R. and Andersen, R. J.} } @article {572, title = {New okadaic acid analogues from the marine sponge Merriamum oxeato and their effect on mitosis}, journal = {Journal of Natural Products}, volume = {66}, number = {6}, year = {2003}, note = {ISI Document Delivery No.: 695CYTimes Cited: 4Cited Reference Count: 25}, month = {Jun}, pages = {838-843}, type = {Article}, abstract = {Inhibitors of the G2 DNA damage checkpoint can selectively sensitize cancer cells with impaired p53 tumor suppressor activity to killing by DNA-damaging drugs or ionizing radiation and have been proposed as a promising therapeutic strategy. An extract from the Northeastern Pacific marine sponge Merriamum. oxeato showed G2 checkpoint inhibitory activity, and fractionation identified the known dinoflagellate toxin dinophysistoxin 1 (1) and the two novel analogues 27-O-acetylokadaic acid (2) and 27-O-acetyldinophysistoxin 1 (3) as the active compounds. The mixture of 1, 2, and 3 was extremely potent at inhibiting the G2 checkpoint (IC50 = 1 ng/mL) and cellular protein Ser/Thr phosphatases (IC50 = 1 ng/mL), and it radiosensitized MCF-7 breast cancer cells expressing mutated p53 at all concentrations tested. However, the mixture of 1, 2, and 3 was also very toxic to cells not exposed to DNA damage (IC50 = 1 ng/mL), making these compounds poor candidates for therapeutic agents to augment the effectiveness of DNA-damaging therapies.}, keywords = {CELL-CYCLE CHECKPOINTS, DNA-DAMAGE CHECKPOINT, ELUCIDATION, INHIBITION, ISOGRANULATIMIDE, P53, PROTEIN-KINASES, TRANSFORMATION}, isbn = {0163-3864}, url = {://000183814600019}, author = {Britton, R. and Roberge, M. and Brown, C. and Van Soest, R. and Andersen, R. J.} } @article {641, title = {The synthesis, structural characterization, and in vitro anti-cancer activity of chloro(p-cymene) complexes of ruthenium(II) containing a disulfoxide ligand}, journal = {Inorganica Chimica Acta}, volume = {352}, year = {2003}, note = {ISI Document Delivery No.: 711FATimes Cited: 39Cited Reference Count: 47}, month = {Aug}, pages = {238-246}, type = {Article}, abstract = {Two diruthenium(II) complexes [RuCl2(p-cymene)](2)(mu-BESE) (1), [RuCl2(p-cymene)](2)(mu-BESP) (2), and the mononuclear salt [RuCl(p-cymene)(BESE)]PF6 (3), containing the disulfoxides BESE and BESP, were synthesized and characterized by elemental analysis, and NMR and IR spectroscopies, and were shown to contain S-bound sulfoxide groups; the disulfoxides are EtS(O)(CH2)(n) S(O)Et, where n = 2 (BESE) or 3 (BESP). Complexes 1 and 3 were also characterized by X-ray crystallography. Preliminary in vitro tests of I and 3 were conducted using the MTT assay, which measures mitochondrial dehydrogenase activity as an indication of cell viability; these complexes showed in vitro anti-cancer activity against a human mammary cancer cell line (MDA-MB-435s) with IC50 values of 360 and 55 muM, respectively. (C) 2003 Elsevier B.V. All rights reserved.}, keywords = {anti-cancer activity, arene complexes, CANCER, cell, COMPLEX, COORDINATION, crystal structures, CRYSTAL-STRUCTURE, DIMETHYL-SULFOXIDE LIGAND, DIRUTHENIUM(II), disulfoxide ligands, INHIBITION, p-Cymene complexes, RADIOSENSITIZING ACTIVITY, ruthenium complexes, SOLUTION CHEMISTRY}, isbn = {0020-1693}, url = {://000184727900029}, author = {Huxham, L. A. and Cheu, E. L. S. and Patrick, B. O. and James, Brian R.} } @article {760, title = {Trisphaerolide A, a novel polyketide from the Dominican sponge Erylus trisphaerus}, journal = {Journal of Natural Products}, volume = {66}, number = {4}, year = {2003}, note = {ISI Document Delivery No.: 673CVTimes Cited: 4Cited Reference Count: 14}, month = {Apr}, pages = {561-563}, type = {Article}, abstract = {The structure of trisphaerolide A (1), a mildly cytotoxic metabolite isolated from extracts of the marine sponge Erylus trisphaerus collected in Dominica, has been elucidated by detailed analysis of spectroscopic data. Trisphaerolide A (1) has a putative polyketide biogenesis, incorporating a rare variant on the standard pathway, which involves the addition of methyl branches arising from C-2 carbons of acetate units to chain carbons that arise from C-1 of acetate units.}, keywords = {biosynthesis, CELL-CYCLE, DNA-DAMAGE CHECKPOINT, INHIBITION, ISOGRANULATIMIDE}, isbn = {0163-3864}, url = {://000182562800025}, author = {van Altena, I. and Van Soest, R. and Roberge, M. and Andersen, R. J.} } @article {5144, title = {Methylated trivalent arsenic species are genotoxic}, journal = {Chemical Research in Toxicology}, volume = {14}, number = {4}, year = {2001}, note = {ISI Document Delivery No.: 424XZTimes Cited: 253Cited Reference Count: 55}, month = {Apr}, pages = {355-361}, type = {Article}, abstract = {The reactivities of methyloxoarsine (MAsIII) and iododimethylarsine (DMAsIII), two methylated trivalent arsenicals, toward supercoiled phi X174 RFI DNA were assessed using a DNA nicking assay. The induction of DNA damage by these compounds in vitro in human peripheral lymphocytes was assessed using a single-cell gel (SCG, "comet") assay. Both methylated trivalent arsenicals were able to nick and/or completely degrade phi X174 DNA in vitro in 2 h incubations at 37 degreesC (pH 7.4) depending on concentration. MAsIII was effective at nicking phi X174 DNA at 30 mM; however, at 150 muM DMAsIII, nicking could be observed. Exposure of (phi X174 DNA to sodium arsenite (iAs(III); from 1 nM up to 300 mM), sodium arsenate (from 1 muM to 1 M), and the pentavalent arsenicals, monomethylarsonic acid (from 1 muM to 3 M) and dimethylarsinic acid (from 0.1 to 300 mM), did not nick or degrade phi X174 DNA under these conditions. In the SCG assay in human lymphocytes, methylated trivalent arsenicals were much more potent than any other arsenicals that were tested. On the basis of the slopes of the concentration-response curve for the tail moment in the SCG assay, MAsIII and DMAsIII were 77 and 386 times more potent than iAs(III), respectively. Because methylated trivalent arsenicals were the only arsenic compounds that were observed to damage naked DNA and required no exogenously added enzymatic or chemical activation systems, they are considered here to be direct-acting forms of arsenic that are genotoxic, though they are not, necessarily, the only genotoxic species of arsenic that could exist.}, keywords = {CELLS, DIMETHYLARSINIC ACID, DRINKING-WATER, ENZYMATIC METHYLATION, FIBROBLASTS, GLUTATHIONE-REDUCTASE, HUMAN, HUMAN URINE, INHIBITION, MONOMETHYLARSONOUS ACID, SODIUM ARSENITE}, isbn = {0893-228X}, url = {://000168260400005}, author = {Mass, M. J. and Tennant, A. and Roop, B. C. and Cullen, W. R. and Styblo, M. and Thomas, D. J. and Kligerman, A. D.} } @article {4916, title = {Cell-based screen for antimitotic agents and identification of analogues of rhizoxin, eleutherobin, and paclitaxel in natural extracts}, journal = {Cancer Research}, volume = {60}, number = {18}, year = {2000}, note = {ISI Document Delivery No.: 358GQTimes Cited: 62Cited Reference Count: 55}, month = {Sep}, pages = {5052-5058}, type = {Article}, abstract = {We describe a cell-based assay for antimitotic compounds that is suitable for drug discovery and for quantitative determination of antimitotic activity, In the assay, cells arrested in mitosis as a result of exposure to antimitotic agents in pure form or in crude natural extracts are detected by ELISA using the monoclonal antibody TG-3, The assay was used to screen >24,000 extracts of marine microorganisms and invertebrates and terrestrial plants and to guide the purification of active compounds from 5 of 119 positive extracts. A new rhizoxin analogue was found in a Pseudomonas species, six new eleutherobin analogues were identified from the octocoral Erythropodium caribaeorum, and two paclitaxel analogues were found in the stem bark of the tree Ilex macrophylla. The assay was also used for quantitative comparison of the antimitotic activity of different analogues. It revealed the importance of the C-11 to C-13 segment of the diterpene core of eleutherobin for its antimitotic activity. The identification of antimitotic compounds in very low abundance and their high (0.5\%) occurrence in natural extracts indicates that drug discovery efforts using this cell-based assay may lead to the identification of structurally novel antimitotic agents.}, keywords = {AGENT, ANTITUMOR, BINDING, fungus, INHIBITION, MACROCYCLIC LACTONE ANTIBIOTICS, MICROTUBULE-STABILIZING AGENTS, MITOTIC SPINDLES, RHIZOPUS-CHINENSIS, TAXOL, TUBULIN POLYMERIZATION}, isbn = {0008-5472}, url = {://000089550600013}, author = {Roberge, M. and Cinel, B. and Anderson, H. J. and Lim, L. and Jiang, X. X. and Xu, L. and Bigg, C. M. and Kelly, M. T. and Andersen, R. J.} } @article {4571, title = {Towards inhibition of yellowing of mechanical pulps. Part III. Hydrogenation of milled wood lignin}, journal = {Journal of Pulp and Paper Science}, volume = {25}, number = {9}, year = {1999}, note = {ISI Document Delivery No.: 235YETimes Cited: 10Cited Reference Count: 18}, month = {Sep}, pages = {312-317}, type = {Article}, abstract = {Oxygenation of hexadecacarbonylhexarhodium(0), Rh-6(CO)(16), in dimethylformamide (DMF) generates nn active catalyst, formulated as Rh-6(mu(3)-O)(4)(OH)(12) (DMF)(n), far the hydrogenation of the aromatic rings of milled wood lignin at similar to 20 degrees C under I atm H-2 in aqueous methyl cellosolve. Partial hydrogenation of the aromatic rings in lignin was confirmed by H-1 NMR spectroscopy. The ability of the catalyst to hydrogenate the lignin model compound 2-methoxy-4-propylphenol is critically dependent on the reaction medium: hydrogenation proceeds faster in aqueous ethanol than in aqueous dioxane, aqueous methyl cellosolve or anhydrous ethanol while no hydrogenation occurs in aqueous DMF.}, keywords = {aromatic compounds, CATALYSTS, CATALYTIC-HYDROGENATION, COMPOUNDS, HYDROGENATION, INHIBITION, lignin model, milled wood lignins, model compounds, OXYGENATION, rhodium compounds, yellowing}, isbn = {0826-6220}, url = {://000082570800002}, author = {Hu, Thomas Q. and James, Brian R. and Wang, Y.} } @article {4571, title = {Towards inhibition of yellowing of mechanical pulps. Part III. Hydrogenation of milled wood lignin}, journal = {Journal of Pulp and Paper Science}, volume = {25}, number = {9}, year = {1999}, note = {ISI Document Delivery No.: 235YETimes Cited: 10Cited Reference Count: 18}, month = {Sep}, pages = {312-317}, type = {Article}, abstract = {Oxygenation of hexadecacarbonylhexarhodium(0), Rh-6(CO)(16), in dimethylformamide (DMF) generates nn active catalyst, formulated as Rh-6(mu(3)-O)(4)(OH)(12) (DMF)(n), far the hydrogenation of the aromatic rings of milled wood lignin at similar to 20 degrees C under I atm H-2 in aqueous methyl cellosolve. Partial hydrogenation of the aromatic rings in lignin was confirmed by H-1 NMR spectroscopy. The ability of the catalyst to hydrogenate the lignin model compound 2-methoxy-4-propylphenol is critically dependent on the reaction medium: hydrogenation proceeds faster in aqueous ethanol than in aqueous dioxane, aqueous methyl cellosolve or anhydrous ethanol while no hydrogenation occurs in aqueous DMF.}, keywords = {aromatic compounds, CATALYSTS, CATALYTIC-HYDROGENATION, COMPOUNDS, HYDROGENATION, INHIBITION, lignin model, milled wood lignins, model compounds, OXYGENATION, rhodium compounds, yellowing}, isbn = {0826-6220}, url = {://000082570800002}, author = {Hu, Thomas Q. and James, Brian R. and Wang, Y.} } @article {3876, title = {Cytotoxic peptides hemiasterlin, hemiasterlin A and hemiasterlin B induce mitotic arrest and abnormal spindle formation}, journal = {Cancer Chemotherapy and Pharmacology}, volume = {39}, number = {3}, year = {1997}, note = {ISI Document Delivery No.: VZ251Times Cited: 66Cited Reference Count: 17}, month = {Jan}, pages = {223-226}, type = {Article}, abstract = {Purpose: Hemiasterlin, hemiasterlin A and hemiasterlin B are newly isolated cytotoxic tripeptides with potential as antitumor drugs. We wished to determine their mechanism of cytotoxicity. Methods: We studied their effect on cell survival, cell cycle progression, and microtubule morphology in MCF-7 human mammary carcinoma cells. Results: At the nanomolar concentrations at which they were cytotoxic, the peptides induced arrest in mitotic metaphase. Hemiasterlin A produced abnormal mitotic spindles like those produced by the microtubule inhibitors taxol, nocodazole and vinblastine at low concentrations. At high concentrations hemiasterlin A did not cause microtubule bundling like taxol, but caused microtubule depolymerization like nocodazole and vinblastine. Conclusions: The hemiasterlins probably exert their cytotoxic effect by inhibiting spindle microtubule dynamics.}, keywords = {CANCER, COLCHICINE SITE, FOSTRIECIN, INHIBITION, microtubules, mitosis, NATURAL-PRODUCTS, OKADAIC ACID, PHOSPHATASE-2A, PODOPHYLLOTOXIN, TAXOL, TUBULIN, VINBLASTINE, VINCA DOMAIN}, isbn = {0344-5704}, url = {://A1997VZ25100008}, author = {Anderson, H. J. and Coleman, J. E. and Andersen, R. J. and Roberge, M.} } @article {4002, title = {Towards inhibition of yellowing of mechanical pulps .1. Catalytic hydrogenation of lignin model compounds under mild conditions}, journal = {Journal of Pulp and Paper Science}, volume = {23}, number = {4}, year = {1997}, note = {ISI Document Delivery No.: WU947Times Cited: 19Cited Reference Count: 19}, month = {Apr}, pages = {J153-J156}, type = {Article}, abstract = {Di-mu-chloro-bis(eta(4)-1,5-hexadiene) dirhodium(I) effectively catalyzed the hydrogenation of the aromatic rings of the lignin model compounds 4-propylphenol, eugenol, 1,2-dimethoxy-4-propylbenzene and 2,6-dimethoxy-4-propyl-phenol under extremely mild conditions (25 degrees C, I atm H-2) in a two-phase, hexane/aqueous pH 7.5 medium. This catalyst was more active than di-mu-chloro-bis(eta(4)-1,5-cyclooctadiene)-dirhodium(I), rhodium(III) trichloride trihydrate and ruthenium(III) trichloride trihydrate. The reactivity of three predominant functional groups in lignin toward the rhodium(I) catalyzed hydrogenation followed the descending order of carbon-carbon double bond > aromatic ring > carbonyl group. The hydrogenation reactions were sensitive to steric and electronic effects of the substituent(s) on the aromatic rings. Moderate to extremely high diastereoselectivities were observed for the hydrogenated products.}, keywords = {aromatic groups, carbonyl groups, CATALYSTS, CHROMOPHORES, eugenol, HYDROGENATION, HYDROGENOLYSIS, INHIBITION, LIGNIN MODEL COMPOUNDS, mechanical pulps, QUINONES, yellowing}, isbn = {0826-6220}, url = {://A1997WU94700002}, author = {Hu, Thomas Q. and James, Brian R. and Lee, C. L.} } @article {4002, title = {Towards inhibition of yellowing of mechanical pulps .1. Catalytic hydrogenation of lignin model compounds under mild conditions}, journal = {Journal of Pulp and Paper Science}, volume = {23}, number = {4}, year = {1997}, note = {ISI Document Delivery No.: WU947Times Cited: 19Cited Reference Count: 19}, month = {Apr}, pages = {J153-J156}, type = {Article}, abstract = {Di-mu-chloro-bis(eta(4)-1,5-hexadiene) dirhodium(I) effectively catalyzed the hydrogenation of the aromatic rings of the lignin model compounds 4-propylphenol, eugenol, 1,2-dimethoxy-4-propylbenzene and 2,6-dimethoxy-4-propyl-phenol under extremely mild conditions (25 degrees C, I atm H-2) in a two-phase, hexane/aqueous pH 7.5 medium. This catalyst was more active than di-mu-chloro-bis(eta(4)-1,5-cyclooctadiene)-dirhodium(I), rhodium(III) trichloride trihydrate and ruthenium(III) trichloride trihydrate. The reactivity of three predominant functional groups in lignin toward the rhodium(I) catalyzed hydrogenation followed the descending order of carbon-carbon double bond > aromatic ring > carbonyl group. The hydrogenation reactions were sensitive to steric and electronic effects of the substituent(s) on the aromatic rings. Moderate to extremely high diastereoselectivities were observed for the hydrogenated products.}, keywords = {aromatic groups, carbonyl groups, CATALYSTS, CHROMOPHORES, eugenol, HYDROGENATION, HYDROGENOLYSIS, INHIBITION, LIGNIN MODEL COMPOUNDS, mechanical pulps, QUINONES, yellowing}, isbn = {0826-6220}, url = {://A1997WU94700002}, author = {Hu, Thomas Q. and James, Brian R. and Lee, C. L.} } @article {4001, title = {Towards inhibition of yellowing of mechanical pulps .2. Water-soluble catalysts for the hydrogenation of lignin model compounds}, journal = {Journal of Pulp and Paper Science}, volume = {23}, number = {5}, year = {1997}, note = {ISI Document Delivery No.: WY102Times Cited: 18Cited Reference Count: 32}, month = {May}, pages = {J200-J205}, type = {Article}, abstract = {Water-soluble, polymer-stabilized, colloidal rhodium is an effective catalyst for the hydrogenation of the aromatic rings of the lignin model compounds 4-propylphenol, 2-methoxy-4-propylphenol, and 1,2-dimethoxy-4-propylbenzene under extremely mild conditions (25 degrees C, 1 atm H-2) in a one-phase, aqueous ethanol medium. The water-soluble catalyst is prepared by reducing rhodium trichloride trihydrate with ethanol in the presence of polyvinylpyrrolidone (PVP) and triethylamine, The reactivity of various chromophore precursors in lignin toward hydrogenation catalyzed by water-soluble, colloidal rhodium follows the descending order of carbon-carbon double bond > aromatic ring in 4-propylphenol > carbonyl group and the aromatic rings in 2-methoxy-4-propylphenol and 1,2-dimethoxy-4-propylbenzene, The hydrogenation of 2-methoxy-4-propylphenol and 1,2-dimethoxy-4-propylbenzene is accompanied by some hydrogenolysis and removal of the OMe group.}, keywords = {aromatic compounds, aromatic groups, CARBON-MONOXIDE, CARBONYL, CATALYSTS, CHROMOPHORES, CLUSTERS, colloids, GROUPS, HIGH-YIELD PULPS, HYDROGENATION, HYDROGENOLYSIS, INHIBITION, LIGNIN, mechanical pulps, model compounds, water solubles, yellowing}, isbn = {0826-6220}, url = {://A1997WY10200002}, author = {Hu, Thomas Q. and James, Brian R. and Lee, C. L.} } @article {4001, title = {Towards inhibition of yellowing of mechanical pulps .2. Water-soluble catalysts for the hydrogenation of lignin model compounds}, journal = {Journal of Pulp and Paper Science}, volume = {23}, number = {5}, year = {1997}, note = {ISI Document Delivery No.: WY102Times Cited: 18Cited Reference Count: 32}, month = {May}, pages = {J200-J205}, type = {Article}, abstract = {Water-soluble, polymer-stabilized, colloidal rhodium is an effective catalyst for the hydrogenation of the aromatic rings of the lignin model compounds 4-propylphenol, 2-methoxy-4-propylphenol, and 1,2-dimethoxy-4-propylbenzene under extremely mild conditions (25 degrees C, 1 atm H-2) in a one-phase, aqueous ethanol medium. The water-soluble catalyst is prepared by reducing rhodium trichloride trihydrate with ethanol in the presence of polyvinylpyrrolidone (PVP) and triethylamine, The reactivity of various chromophore precursors in lignin toward hydrogenation catalyzed by water-soluble, colloidal rhodium follows the descending order of carbon-carbon double bond > aromatic ring in 4-propylphenol > carbonyl group and the aromatic rings in 2-methoxy-4-propylphenol and 1,2-dimethoxy-4-propylbenzene, The hydrogenation of 2-methoxy-4-propylphenol and 1,2-dimethoxy-4-propylbenzene is accompanied by some hydrogenolysis and removal of the OMe group.}, keywords = {aromatic compounds, aromatic groups, CARBON-MONOXIDE, CARBONYL, CATALYSTS, CHROMOPHORES, CLUSTERS, colloids, GROUPS, HIGH-YIELD PULPS, HYDROGENATION, HYDROGENOLYSIS, INHIBITION, LIGNIN, mechanical pulps, model compounds, water solubles, yellowing}, isbn = {0826-6220}, url = {://A1997WY10200002}, author = {Hu, Thomas Q. and James, Brian R. and Lee, C. L.} } @article {3819, title = {Structural coupling of the inhibitory regions flanking the ETS domain of murine Ets-1}, journal = {Protein Science}, volume = {5}, number = {2}, year = {1996}, note = {ISI Document Delivery No.: TU724Times Cited: 46Cited Reference Count: 66}, month = {Feb}, pages = {296-309}, type = {Article}, abstract = {Several members of the ets gene family of transcription factors show negative regulation of DNA binding by intramolecular interactions. A structural mechanism for this auto-inhibition is investigated using a 161-residue N-terminal deletion mutant of murine Ets-1, Ets-1 Delta N280. This protein shows a similar reduced affinity for DNA as native Ets-1 because it contains the ETS domain in context of the flanking amino- and carboxy-terminal regions that together mediate repression of DNA binding. The secondary structure of Ets-1 Delta N280 was determined using NMR chemical shift, NOE, J coupling, and amide hydrogen exchange information. In addition to the winged helix-turn-helix ETS domain, Ets-1 Delta N280 contains two alpha-helices in the amino-terminal inhibitory region and one alpha-helix in the carboxy-terminal inhibitory region. Chemical shift comparisons were made between this protein and an activated form of Ets-1 lacking the amino-terminal inhibitory region. The spectral differences demonstrate that the amino- and carboxy-terminal inhibitory sequences are structurally coupled to one another, thus explaining the observation that both regions are required for the repression of DNA binding. Furthermore, these data show that the inhibitory sequences also interact directly with the first helix of the intervening ETS domain, thereby providing a pathway for the repression of DNA binding. These results lead to a model of an inhibitory module in Ets-1 composed of both the amino- and carboxy-terminal regions interfaced with the ETS domain. This establishes the structural framework for understanding the intramolecular inhibition of Ets-1 DNA binding.}, keywords = {3-DIMENSIONAL NMR-SPECTROSCOPY, allosteric, ASSIGNMENT, CRYSTAL-STRUCTURE, DNA binding, DNA-BINDING MOTIF, ETS domain, Ets-1 and Ets-2, FACTORS, H-1, INHIBITION, INTRAMOLECULAR, LARGER PROTEINS, N-15 NMR, NMR, protein structure, SPECTRA, transcription, V-ETS, winged helix-turn-helix}, isbn = {0961-8368}, url = {://A1996TU72400014}, author = {Skalicky, J. J. and Donaldson, L. W. and Petersen, J. M. and Graves, B. J. and McIntosh, L. P.} }