bluuebunny/crossref_metadata_2025_split huggingface dataset:
Syntheses and biological activities of novel diheterocyclic compounds containing 1,2,4‐triazolo[1,5‐a]pyrimidine and 1,3,4‐oxadiazole
Authors: Liu Zuming , Yang Guangfu , Qin Xianghua 
Published: January 2005

AbstractIn a search for novel agrochemicals with high activity and low toxicity, a series of diheterocyclic compounds containing 1,2,4‐triazolo[1,5‐a]pyrimidine and 1,3,4‐oxadiazole rings were designed and synthesized by a four‐step synthetic route starting from 2‐mercapto‐5,7‐dimethyl‐1,2,4‐triazolo[1,5‐a]pyrimidine. The structures of all the compounds synthesized were confirmed by 1H NMR, mass spectroscopy and elemental analysis. The preliminary bioassay against Brassica campestris L and Echinochloa crusgalli Beavu indicated that the title compounds displayed herbicidal activity at the concentration of 100 ppm and that compounds 5a (R = CH3), 5d (R = C2H5) and 5f (R = i‐Bu) were found to have particularly high activities. In addition, the results of an in vivo test at a concentration of 50 ppm showed that all the compounds prepared were highly active against Rhizoctonia slain, but not active against Fusarium oxysporum, Gibberella zeave and Phoma sparagi. A further in vivo test showed that compound 5j possessed better fungicidal activity against Rhizoctonia solani at a concentration of 200 ppm than Carbendazim and Validamycin A, which are well known for their fungicidal activity against Rhizoctonia solani. To our knowledge, this is the first report that 1,2,4‐triazolo[1,5‐a]pyrimidine derivatives display fungicidal activity against Rhizoctonia solani.© 2001 Society of Chemical Industry
Electrokinetic remediation of lead‐, zinc‐ and cadmium‐contaminated soil
Authors: Vengris Tomas , Binkienė Rima , Sveikauskaitė Aušra 
Published: January 2005

AbstractElectrokinetic remediation of lead‐, zinc‐ and cadmium‐contaminated sand and clayey soils has been investigated under laboratory‐scale conditions. Soil extracts of heavy metals (by 1 M HCl solution) were analysed by optical emission spectrometry. The efficiency of electrochemical remediation was partially dependent on the pH of the soil media. With pH increase, the migration of heavy metal ions toward the cathode was limited. When acetic acid was added to the sandy soil, almost complete remediation was achieved. A clay layer inserted in the cathode area did enhance the remediation rate. The most effective clean‐up was achieved for zinc and cadmium, with less effective clean‐up being achieved for lead. The effectiveness of the electrokinetic remediation of heavy metal‐contaminated clayey soil was low. The appropriate acidity was not achieved using acetic acid because of the high buffering capacity of clay, and metal ion migration was impeded by its sorption onto some clay components. The conclusion was made that clays could be used as immobilizing media for heavy metal ions by electrokinetic remediation of various soils.© 2001 Society of Chemical Industry
Partitioning behaviour of cephalexin and 7‐aminodeacetoxicephalosporanic acid in PEG/ammonium sulfate aqueous two‐phase systems
Authors: Zhu Jian‐Hang , Wei Dong‐Zhi , Cao Xue‐Jun , Liu Ye‐Qing , Yuan Zhong‐Yi 
Published: January 2005

AbstractIn order to develop an aqueous two‐phase system (ATPS) for cephalexin synthesis with extractive bioconversion, the partitioning behaviour of cephalexin and 7‐aminodeacetoxicephalosporanic acid (7‐ADCA) in poly(ethylene glycol) (PEG)/salt ATPS were examined. Parameters such as PEG size, salt type and tie line length were investigated to find a primary extraction system. In PEG400/ammonium sulfate and PEG400/magnesium sulfate systems, the partition coefficient of cephalexin (KC) was larger than 1 while that of 7‐ADCA (KA) deviated about 1.5. Addition of neutral salts, surfactants and water‐miscible solvents were also investigated in the primary ATPS in order to improve the separation efficiency.KCgreatly increased when neutral salts and surfactants were added to the PEG400/ammonium sulfate primary systems whereasKAwas only slightly higher than that of the additive‐free ATPS. In an improved ATPS for extractive bioconversion, consisting of PEG400 (20% w/w), ammonium sulfate (17.5% w/w), methanol (5% w/w) and NaCl (3% w/w), aKCvalue of up to 15.2 was achieved;KAwas 1.8;KP(partition coefficient of phenylglycine methyl ester) was 1.2 and the recovery yield of cephalexin was 94.2%. The results obtained from the extractive bioconversion of cephalexin in the improved ATPS showed that it is feasible to perform such an enzymatic process in an ATPS and the system offers the potential as a model for enzymatic synthesis of some water soluble products.© 2001 Society of Chemical Industry
Prediction of functional tertiary interactions and intermolecular interfaces from primary sequence data
Authors: Pang Phillip S. , Jankowsky Eckhard , Wadley Leven M. , Pyle Anna Marie 
Published: January 2005

AbstractGiven the availability of sequence information for many species, one can examine how the sequence of a gene varies among different organisms. This is accomplished by aligning the sequences and observing patterns of conservation, mutation and counter‐mutation at different positions in the gene. Imbedded in these patterns is information on energetic coupling and macromolecular interactions, which can be deciphered by application of statistical algorithms. Here we report a robust approach for predicting interactions within (or between) any type of biopolymer, including proteins, RNAs and RNA‐protein complexes. Rather than maximize the number of predictions, this approach is designed to detect a limited number of highly significant interactions, thereby providing accurate results from alignments that contain a modest number of sequences (20–60). The versatility and accuracy of the algorithm is demonstrated by the successful prediction of important intramolecular interactions within RNAs, modified RNAs, and proteins, as well as the prediction of RNA‐protein and protein‐protein interactions. J. Exp. Zool. (Mol. Dev. Evol.) 304B:000000, 2005. © 2005 Wiley‐Liss, Inc.
N,N′,N″,N‴‐tetraalkylcyclam derivatives: synthesis, 99mTc‐labelling and biological properties
Authors: Jeong Jae Min , Hong Sung Hyun , Kim Young Joo , Lee Dong Soo , Chung June‐Key , Cho Jung‐Hyuck , Lee Myung Chul 
Published: January 2005

AbstractWe synthesized N,N′,N″,N‴‐tetraalkylcyclam derivatives in which alkyl groups were ethyl, propyl, butyl, methoxyethyl, and ethoxyethyl. We attempted to label the compounds with 99mTc. The cyclams with methyl, ethyl, and propyl could be labelled. The labelled N,N′,N″,N‴‐tetraalkylcyclam derivatives showed +1 charge. They excreted rapidly through the kidney in mice. The liver‐uptake increased slightly as the lipophilicity increased. However, the myocardial uptake was low unlikely with the +1 charged myocardial imaging agents. Copyright © 2001 John Wiley & Sons, Ltd.
Hydrogen‐deuterium exchange during the reductive deuteration of α‐ and γ‐tocopherol chromenes
Authors: Lei Huangshu , Atkinson Jeffrey 
Published: January 2005

AbstractReduction of tocopherol chromenes with heterogeneous catalysts and deuterium gas resulted in various degrees of deuterium incorporation despite the use of high purity deuterium gas. Exchange of hydrogens on C‐7 of γ‐tocopherol was evident by 2H‐NMR and could be controlled by consideration of the substrate (chromene) to catalyst ratio, concentration and temperature. Tocopherols deuterated at C3 and C4 were prepared with 94% d2 incorporation using 10% Pd/C at 0°C in ethyl acetate. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of 13C3,15N4‐labeled factor Xa inhibitor
Authors: Guilford William J. , Dallas Jerry , Arnaiz Damian 
Published: January 2005

AbstractThe synthesis of an isotopically‐labeled, diphenoxypyridine factor Xa inhibitor, 3‐[[6‐[3‐(4,5‐dihydro‐1‐(13C)‐methyl‐1H‐(4‐13C,15N2‐imidazol‐2‐yl)phenoxy)‐3,5‐difluoro‐4‐(4‐morpholinyl)‐2‐pyridinyl]oxy]‐4‐hydroxybenzene‐13C‐carbox‐15N‐imid‐15N‐amide, is reported for use in factor Xa binding studies using REDOR NMR. N‐benzyl protected tetralabeled N‐methylethylene diamine was an intermediate in the preparation of 3‐[4,5‐1‐(13C)‐methyl‐1H‐(4‐13C,15N2‐imidazol‐2‐yl)]phenol. Copyright © 2001 John Wiley & Sons, Ltd.
Enzyme catalysed synthesis of L‐[4‐11C]aspartate and L‐[5‐11C]glutamate
Authors: Antoni G. , Omura H. , Ikemoto M. , Moulder R. , Watanabe Y. , Långström B. 
Published: January 2005

AbstractThe nitriles β‐[11C]cyano‐L‐alanine 1 and γ‐[11C]cyano‐α‐amino‐L‐butyric acid 2 were obtained by enzymatic catalysis from O‐acetyl‐L‐serine and O‐acetyl‐L‐homoserine with carrier added hydrogen [11C]cyanide (0.1 µmol), using O‐acetyl‐L‐serine sulfhydrylase [EC.4.2.99.8] and O‐acetyl‐L‐homoserine sulfhydrylase [EC.4.2.99.10], respectively. L‐[4‐11C]Aspartate 3 and L‐[5‐11C]glutamate 4 were then obtained by alkaline hydrolysis of 1 and 2, respectively. Purification by semi‐preparative HPLC yielded 3 and 4 with radiochemical purities higher than 95% and with decay corrected radiochemical yields of 60–70% and 50–60%, respectively based on the total amount of collected hydrogen [11C]cyanide. The enantiomeric purities were determined, after derivatisation with N‐α‐(2,4‐dinitrophenyl‐5‐fluoro‐)‐L‐alaninamide, by HPLC to be higher than 97.5%. The total reaction times for 3 and 4, counted from end of bombardment, were 50–55 min. The specific radioactivity of 3 and 4 were approximately 30 GBq/µmol at end of synthesis starting from 20 GBq hydrogen [11C]cyanide. Copyright © 2001 John Wiley & Sons, Ltd.
Comparative evaluation of 99mTc‐ethylene bis‐l‐cysteine and 99mTc‐ethylene bis‐l‐β‐homocysteine during reversed phase HPLC analysis and electrophoresis at various pH conditions
Authors: Mang'era K.O. , Tassaert S. , Cleynhens B. , Verbruggen A. , Verbeke K. 
Published: January 2005

AbstractEthylene bis‐L‐β‐homocysteine (L,L‐EH) differs from ethylene bis‐L‐cysteine (L,L‐EC) in having an extra methylene group between each pair of amine and carboxyl groups. The objective of this study was to determine the effect of the extra methylene groups on the characteristics of the complex of these compounds with technetium‐99m during analysis by reversed phase HPLC and by electrophoresis at various pH values. Up to pH 5.5, 99mTc‐L,L‐EH exhibits a substantially longer retention time during reversed phase HPLC than 99mTc‐L,L‐EC, suggesting a more lipophilic character for 99mTc‐L,L‐EH under these conditions. On the other hand, 99mTc‐L,L‐EH clearly possesses a higher negative charge in the pH range 3‐6.5 as shown by the markedly greater migration towards the anode in electrophoresis experiments. A rational explanation for these seemingly opposing observations can not yet be offered. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of N‐protected 14C‐Labelled (2E)‐5‐amino‐5‐methylhex‐2‐enoic acid analogues
Authors: Jessen Claus U. , Selvig Helle , Valsborg Jacob S. 
Published: January 2005

AbstractA novel method of preparing N‐protected (2E)‐5‐amino‐5‐methylhex‐2‐enoic acids has been developed based on the synthesis of 3‐methyl‐3‐amino‐butanol. The method was used to synthesise 14C‐labelled compounds of (1) via synthesis of triethylphosphono[1‐14C]acetate. Copyright © 2001 John Wiley & Sons, Ltd.
International Isotope Society. Abstracts of the Xth I.I.S. (UK Group) Symposium. Current themes in Isotopic chemistry.
Authors: Pringle Paul G , Olsen Henrik , Lemoucheux Laurent , Rouden Jacques , Lasne Marie‐Claire , Rayner Christopher M. , Antoni G. , Björkman M. , Kihlberg Tor , Ögren M. , Långström Bengt , Wiltshire H. R. , Buss N. , Hill Alison M. , Shipley Nick , Kingston L. P. , Lockley W. J. S. , Mather A. N. , Thompson S. P. , Wilkinson D. J. , Booth H. , Dedinas R. F. , Harding J. R. , White D. F. 
Published: January 2005

AbstractThe tenth annual symposium of the International Isotope Society's United Kingdom Group took place at the Alderley Park site of AstraZeneca plc. The symposium was attended by over 80 delegates from academia, the pharmaceutical and agrochemical industries, life science and fine chemical companies. Delegates were welcomed to the site by Dr Peter Warner of the Medicinal Chemistry Department.The scientific programme consisted of presentations on isotopic chemistry and applications of labelled compounds, or of chemistry with significant implications for isotopic synthesis. Both short‐lived and long‐lived isotopes were represented, as were stable isotopes. The programme was split into a morning and afternoon session chaired by Dr John Harding (AstraZeneca, who also organised the excellent domestic programme) and Dr Karl Cable (Glaxo Wellcome). The meeting ended with concluding remarks from Dr Ken Lawrie (SmithKline Beecham), chairman of the UK Group. This years symposium had a larger attendance from other European countries, an excellent level of sponsorship was achieved, and the symposium proved self‐financing.The next UK group symposium is planned for early October 2001.Meeting Programme

Paul Pringle [University of Bristol, UK] To what extent can Homogeneous Catalysts be Designed?
Henrick Olsen [Novo Nordisk, Denmark] Mapping of Pharmaceutical Degradation Products in the Solid Dosage Form using Radiotracers.
Marie‐Claire Lasne [University of Caen, France] Synthesis of New Ligands of Cholinergic Receptors. Strategies for their Radiolabelling with Positron Emitters, Carbon‐11 or Fluorine‐18.
Christopher Rayner [University of Leeds, UK] Catalysis in Supercritical Carbon Dioxide ‐ What advantages does it have to Offer?
Gunnar Antoni, [University of Uppsala, Sweden] Position Specific Labelling of Biomedically Interesting Compounds using Short‐Lived Radionuclides.
Hugh Wiltshire [Hoffmann‐La Roche, UK] The Use of Stable‐Labelled Isotopes in Bioequivalence Studies with the HIV‐Protease inhibitor Saquinavir.
Alison Hill [Kings College, UK] Elucidation of Soraphen A Biosynthesis using 2H, 13C and 18O‐Labelled Precursors.
Nick Shipley [Glaxo Wellcome, UK] Preparation of P450 Substrates for use in Drug‐drug Interactions
Andrew Mather [AstraZeneca, UK] Aspects of Isotopic Labelling by Parallel Chemistry.
Helen Booth [Astra Zeneca, UK] Synthesis of 14C‐labelled forms of a series of Human Leukocyte Elastase Inhibitors.
Synthesis of tritium labeled [3R‐3H]‐, and [3S‐3H]‐L‐phenylalanine
Authors: Jemielity J. , Kanski R. , Kanska M. 
Published: January 2005

AbstractThe synthesis of two selectively labeled isotopomers of L‐phenylalanine, (Phe), using chemical and enzymatic methods is reported. The [3R‐3H]‐L‐Phe isotopomer has been obtained from [3‐3H]cinnamic acid prepared from benzaldehyde and malonic acid using tritiated water as a source of radioactive label, and by addition of ammonia in the presence of enzyme PAL. The [3S‐3H]‐L‐Phe isotopomer has been synthesized by addition of ammonia to cinnamic acid in a buffered medium containing PAL and tritiated water. Copyright © 2001 John Wiley & Sons, Ltd.
Simultaneous preparation of 16α‐[18F]fluoroestradiol‐sulphamates in an automated module. A high‐yield procedure for 16α‐[18F]fluoroestradiol‐17β‐sulphamate
Authors: Römer J. , Füchtner F. , Steinbach J. , Kasch H. 
Published: January 2005

AbstractAfter successfully synthesizing 16α‐[18F]fluoroestradiol‐3,17β‐disulphamate in an automatic procedure, we studied the conditions for obtaining 16α‐[18F]fluoroestradiol‐monosulphamates in a similar manner. The described procedure can simultaneously provide approximately 3 GBq of 16α‐[18F]fluoroestradiol‐3‐sulphamate and 1 GBq of 16α‐[18F]fluoroestradiol‐17β‐sulphamate of high radiochemical purity. By treating 16α‐[18F]fluoroestradiol‐3,17β‐disulphamate with Kryptofix 2.2.2 and potassium carbonate, 16α‐[18F]fluoroestradiol‐17β‐sulphamate also becomes available at high radioactivity. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of 3H and fluorescence‐labelled poly (DL‐Lactic acid)
Authors: Ponsart S. , Coudane J. , Morgat J.‐L. , Vert M. 
Published: January 2005

AbstractThe novel polymer modification method based on the activation of an aliphatic polyester chain by using lithium diisopropylamide at low temperature to form a polycarbanion bearing nucleophilic sites in a position α to the carbonyl groups was applied to rac‐poly (lactic acid), PLA50, to label this polymer with radioactive tritium atoms or with a fluorescent dye. Despite simultaneous partial chain degradation, radioactive PLA50 and fluorescent PLA50 with Mn=14000 g mol−1, Mw/Mn=1.9 and Mn=32 000 g mol−1, Mw/Mn=2.4, respectively, were obtained. The specific activity of the final compound was 3.7 µCi g−1 that squared with 0.3‰ substitution reaction. The fluorescent polymer was substituted with 0.25% ratio. This work shows that the LDA activation method appears to have considerable potential. Copyright © 2001 John Wiley & Sons, Ltd.
Isotopic methylation
Authors: Bolton R. 
Published: January 2005

AbstractThis review reports recent methods by which organic compounds, and especially pharmaceuticals, have been isotopically labelled by the incorporation of carbon or hydrogen isotopes in methylation processes. Particular attention is paid to the incorporation of carbon‐11; both the synthesis of such labelled methylating agents and applications of their use are discussed. The review has reported reagents and conditions by which a number of organic compounds have been obtained recently. It also assesses the limitations of reported methods and proposes some alternative techniques and innovations.The application of catalysts such as Ag+ and conditions such as microwave irradiation to encourage these reactions are also included, with suggestions of other, potentially beneficial, ways to assist them.In many cases, the radio‐chemical yield and purity of the labelled product are given along with an estimate of the total reaction time. Copyright © 2001 John Wiley & Sons, Ltd.
[6, 7, 10, 11‐13C4]‐Labelled leukotriene B4 synthesis: standard for mass spectrometry determination and metabolic studies
Authors: Treilhou Michel , Couderc François 
Published: January 2005

AbstractThe mass spectrometry quantification and metabolic studies of leukotriene B4 (LTB4) in biological fluids require standards labelled with stable isotopes. This paper describes the synthesis of LTB4 labelled with 13C in positions 6, 7, 10 and 11 (1). These labelled carbons come from 13C2‐acetylene. A labelled LTB4 is obtained with an isotopic enrichment of 99%. Copyright © 2001 John Wiley & Sons, Ltd.
Carbon‐14 labeling of a trifluoromethoxy group: synthesis of a substance P antagonist
Authors: Raab Conrad E. , Dean Dennis C. , Melillo David G. 
Published: January 2005

AbstractSynthesis of a carbon‐14 labeled trifluoromethoxy group has been accomplished using the stepwise oxidative fluorination–desulfurization of a readily prepared [14C]xanthate (5). This novel labeling procedure allowed a rapid synthesis of substance P antagonist candidate 1 that avoided potentially more complex ring‐labeling procedures. Similar procedures have been used to prepare C‐14 labeled trifluoromethyl and trifluoromethylamine groups. Copyright © 2001 John Wiley & Sons, Ltd.
Improved specific Synthesis of [1′‐15N]‐ and [3′‐15N]L‐histidine
Authors: Soede‐Huijbregts C. , van Laren M. , Hulsbergen F. B. , Raap J. , Lugtenburg J. 
Published: January 2005

AbstractSpecifically, 15N‐enriched L‐histidines have been prepared. The labelling methodology involves introduction of labels in its precursor 1‐benzyl‐5‐hydroxy methyl imidazole, which is converted into L‐histidine via the Schöllkopf method. The procedure allows the preparation of the intermediates and finally histidine with high 15N enrichment (99%) at each position, in 29% overall yield starting with 15NH4Cl and 56% with KSC15N, respectively. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and in vitro evaluation of iodine labelled pyrazolo[1,5‐a]pyridines as highly selective dopamine D4 receptor ligands
Authors: Prante O. , Löber S. , Hübner H. , Gmeiner P. , Kuwert T. 
Published: January 2005

AbstractTwo 131I‐labelled radioligands, namely 3‐(4‐[131I]iodophenylpiperazin‐1‐ylmethyl)‐pyrazolo[1,5‐a]pyridine and 3‐(4‐chlorophenylpiperazin‐1‐ylmethyl)‐7‐[131I]iodopyrazolo[1,5‐a]pyridine, which are required for studies or binding of these ligands to the D4 receptor, have been synthesized in 80% and 32% radiochemical yields, respectively; the radiochemical purity in each case was >97%. For the second radioligand a kit preparation, based on iododestannylation followed by solid‐phase extraction, was possible. In vitro characterization using CHO‐cells expressing different dopamine receptor subtypes gave Ki values of 3.1 and 2.6 nM. Both radioligands are highly selective for the D4 subtype as compared to other dopamine subtypes. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of [11C]levofloxacin
Authors: Berridge M. S. , Burnazi E. M. 
Published: January 2005

AbstractLevofloxacin, the pure S enantiomer of the fluoroquinolone antibiotic ofloxacin, was labeled via methylation of the corresponding, des‐methyl, secondary amine with N.C.A. [11C]methyl iodide. The methylation reaction was regioselective, giving predominantly the preferred methyl amine at high temperature in DMF, while otherwise giving predominantly the methyl ester of a free carboxylic acid also present in the molecule. Levofloxacin was obtained in 80% chemical yield after a 45 min synthesis. Copyright © 2001 John Wiley & Sons, Ltd.
Investigations into the regioselective deuteriation of enolates derived from silyl enol ethers and enolacetates
Authors: Coumbarides Gregory S. , Eames Jason , Weerasooriya Neluka 
Published: January 2005

AbstractResults are reported on the regioselective C‐deuteriation of a series of enolates derived from the addition of MeLi to the related enolacetate and silyl enol ether and discussed in terms of the similarity between these methods; comments are made on the possible role of the additive, lithium tert‐butoxide. Copyright © 2001 John Wiley & Sons, Ltd.
Magnetic resonance imaging of in vivo kinematics after total knee arthroplasty
Authors: Lee Keh‐Yang , Slavinsky John P. , Ries Michael D. , Blumenkrantz Gabrielle , Majumdar Sharmila 
Published: January 2005

AbstractPurposeTo improve the quality of magnetic resonance imaging (MRI) on knees after total knee arthroplasty (TKA) by minimizing image artifacts caused by metallic implants, and to establish a method determining in vivo kinematics of TKA knees using MRI.Materials and MethodsTwo knee implants made of cobalt‐chrome and oxidized zirconium were tested with different pulse sequences and imaging parameters. Then, in vivo kinematic MRI was performed on five well‐functioning TKAs under simulated weight‐bearing conditions. Kinematic measurements were made and a linear correlation test was run between the tibio‐ and patellofemoral measurements.ResultsThe best images with minimum metallic artifacts were observed using oxidized zirconium implants, a fast spin echo sequence (FSE), thin slice thickness, and high readout gradient. TKA kinematics exhibited a large deviation from the normal kinematics and considerable patient‐to‐patient variability. However, significant linear correlations between tibiofemoral and patellofemoral kinematics were observed (R = −0.96, 0.92, 0.88).ConclusionMetallic artifacts due to orthopedic implants can be reduced in MR images for some materials, appropriate pulse sequence, and imaging parameters selection, enabling MR quantification of knee kinematics. Tibiofemoral kinematics appears to affect patellofemoral position after total knee arthroplasty. J. Magn. Reson. Imaging 2005;21:172–178. © 2005 Wiley‐Liss, Inc.