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51.
The synthesis of 2′,6′-diazafolic acid was accomplished by the condensation of 2-acetylamino-4(3H)pteridinone-6-earboxaldehyde (XIV) with diethyl N-[(5-amino-2-pyrimidinyl)carbonyl]-L-glutamate (XIII) followed by reduction of the anil double bond and alkaline hydrolylic cleavage of the N2-acetyl and ethyl ester protecting groups. Intermediate XIII was prepared by starling with 5-nitro-2-styrylpyrimidine (VI) and proceeding via 5-arnino-2-styrylpyrimidine (IX). The henzyloxycarbonyl derivative of IX was prepared and oxidized to the corresponding 5-benzyloxycarbonylaminopyrimidine-2-carboxylic acid (XI). The coupling of XI with diethyl L-glutamate followed by hydrogenolysis of the henzyloxycarbonyl function afforded the desired intermediate XIII. 2′,6′-Diazafolic acid was a potent inhibitor of Streptococcus faecium and displayed marginal activity against leukemia 1,1210 in mice. 相似文献
52.
[reaction: see text] Copper(I)-mediated C-N bond formation has been employed to prepare both N-acyl vinylogous carbamic acids and ureas. The novel N-acyl vinylogous carbamic acid antibiotic, CJ-15,801, was synthesized using this methodology. 相似文献
53.
Thiam Seong Chong 《Journal of organometallic chemistry》2006,691(4):687-692
The rate constant for the methyl abstraction reaction of CpFe(CO)2Me has been measured with the benzyl radical clock as (1.1 ± 0.2) × 105 M−1 s−1 at room temperature. Time-resolved Fourier-transform Infrared (FTIR) absorption spectroscopy pointed towards the formation of the CpFe(CO)2 radical upon benzyl abstraction. The main stable product has been established by a linear scan of the reaction mixture as Cp2Fe2(CO)4 produced by the dimerization of the CpFe(CO)2 radicals. The transition state structure for the abstraction process was also found at UB3LYP/6-311+G* level of theory to contain a planar CH3 group. 相似文献
54.
A quantitative compressed pellet infrared method used together with a micro-distillation to effect separation of the isomer has been developed and reported here for the analysis of ortho-, meta-, and para-terphonyl. The terphenyl content is determined on fractions isolated by distillation from radiation damaged samples. The compressed pellet infrared method is preferred instead of the more conventional solution technique since smaller quantities of isolated terphcnyl are required. The pellet method is applicable also to polyphenyls higher than the terphenyls. The solution technique is not due to the insolubility of the polyphenyls. It is expected that the compressed pellet spectral method developed here might well find application in the analysis of compounds other than polyphenyls. Results presented here appear to be the, first quantitative infrared data reported in the literaturu on polyphenyl compounds. 相似文献
55.
A study of the reaction of Me3SnCu·.Me2S (1) and [Me3SnCuSPh]Li (2) with α,β - acetylenic N,N-dimethylamides 3 shows (a) that the overall process can be controlled experimentally so as to produce either N,N-dimethyl ()-(4) or ()-3-trimethylstannyl-2-alkenamides (5), (b) that the initially formed intermediate derived from interaction of 2 and 3 is significantly more stable than that obtained by reaction of 2 and α,β-acetylenic esters, and (c) that the intermediate produced by treating 3 with 1 can be trapped with electrophiles other than proton. 相似文献
56.
Adsorption of NH3 onto activated carbon prepared from palm shells impregnated with H2SO4 总被引:3,自引:0,他引:3
Adsorption of ammonia (NH3) onto activated carbons prepared from palm shells impregnated with sulfuric acid (H2SO4) was investigated. The effects of activation temperature and acid concentration on pore surface area development were studied. The relatively large micropore surface areas of the palm-shell activated carbons prepared by H2SO4 activation suggest their potential applications in gas adsorption. Adsorption experiments at a fixed temperature showed that the amounts of NH3 adsorbed onto the chemically activated carbons, unlike those prepared by CO2 thermal activation, were not solely dependent on the specific pore surface areas of the adsorbents. Further adsorption tests for a wide range of temperatures suggested combined physisorption and chemisorption of NH3. Desorption tests at the same temperature as adsorption and at an elevated temperature were carried out to confirm the occurrence of chemisorption due to the interaction between NH3 and some oxygen functional groups via hydrogen bonding. The surface functional groups on the adsorbent surface were detected by Fourier transform infrared spectroscopy. The amounts of NH3 adsorbed by chemisorption were correlated with the contents of elemental oxygen present in the adsorbents. Mechanisms for chemical activation and adsorption processes are proposed based on the observed phenomena. 相似文献
57.
Chong BE Lubman DM Rosenspire A Miller F 《Rapid communications in mass spectrometry : RCM》1998,12(24):1986-1993
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) has been used to rapidly profile the protein content of human cell lysates from MCF-10 cell and variant lines. The method was used to study the protein profiles of these cells as they progressed from normal breast epithelium to fully malignant cells. Distinct differences in the protein profiles were observed with progression, and specific proteins associated with carcinogenesis (p53, c-myc, and c-erbB-2) were heavily expressed in these cells as detected by MALDI-TOFMS. These proteins were also isolated using non-porous reversed-phase high performance liquid chromatography (NP-RP-HPLC) and mass analyzed by MALDI-TOFMS to provide molecular weight information without interference from other proteins in the whole cell lysates, and to avoid suppression effects in mixtures of proteins detected by MALDI-TOFMS. In order to confirm the identity of these oncoproteins, the cell lysates were subjected to one-dimensional (1-D) gel separation and subsequently electroblotted onto a poly(vinylidene difluoride) (PVDF) membrane for further analysis. Trypsin and cyanogen bromide digestions were performed on these proteins eluted from excised PVDF bands which were then analyzed by MALDI-TOFMS. The identity of these proteins was confirmed by database matching procedures. 相似文献
58.
Chong BE Yan F Lubman DM Miller FR 《Rapid communications in mass spectrometry : RCM》2001,15(4):291-296
A novel two-dimensional two-column liquid chromatography/mass spectrometry (LC/MS) technique is described in this work, where chromatofocusing (CF) has been coupled to nonporous reversed-phase (NPS-RP) HPLC to separate proteins from human breast epithelial whole cell lysates. The liquid fractions from NPS-RP-HPLC are readily amenable to direct on-line analysis using electrospray ionization orthogonal acceleration time-of-flight mass spectrometry (ESI-TOFMS). A key advantage of this technique is that proteins can be 'peeled off' in the liquid phase from the CF column according to their isoelectric points (pI) in the first chromatographic separation dimension. The NPS-RP-HPLC column further separates these pI-focused fractions based upon protein hydrophobicity as the second chromatographic dimension. The third dimension involves on-line molecular weight determination using ESI-TOFMS. As a result, this method has the potential to be fully automated. In addition, a 2-D protein map of pI versus molecular weight is generated, which is analogous to a 2-D gel image. Thus, this technique may provide a means to study differential expression of proteins from whole cell lysates. 相似文献
59.
Eugene A. Komissarov Yuri I. Baukov Eugeniya P. Kramarova Sergey Yu. Bylikin Vadim V. Negrebetsky Alexander A. Korlyukov 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(4):m144-m146
In the title compound, [Ge(C8H14NO)2Cl]CF3SO3, which is the first complex containing an eight‐membered lactam (enantholactam) as ligand, the coordination polyhedron of the GeIV atom is intermediate between trigonal–bipyramidal and square‐pyramidal. Quantum chemical calculations of the crystal structure indicate the absence of additional coordination bonding between the GeIV atom and the trifluoromethanesulfonate anion. 相似文献
60.
James P. Kutney Eugene Dimitriadis Gary M. Hewitt Philip J. Salisbury Mahatam Singh James A. Servizi Dennis W. Martens Robert W. Gordon 《Helvetica chimica acta》1982,65(5):1343-1350
One of the fish-toxic chlorinated resin acids, 14-chlorodehydroabietic acid ( 5 ), found in kraft mill effluent is examined. When exposed to the fungus Mortierella isabellina, 5 is converted into a number of hydroxylated derivatives which show low levels of toxicity to fish. These biotransformation products were isolated and characterized. 相似文献