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排序方式: 共有121条查询结果,搜索用时 859 毫秒
1.
Functional Binding Surface of a β‐Hairpin VEGF Receptor Targeting Peptide Determined by NMR Spectroscopy in Living Cells 下载免费PDF全文
Dr. Donatella Diana Anna Russomanno Dr. Lucia De Rosa Dr. Rossella Di Stasi Dr. Domenica Capasso Dr. Sonia Di Gaetano Dr. Alessandra Romanelli Dr. Luigi Russo Dr. Luca D. D'Andrea Prof. Roberto Fattorusso 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):91-95
In this study, the functional interaction of HPLW peptide with VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) was determined by using fast 15N‐edited NMR spectroscopic experiments. To this aim, 15N uniformly labelled HPLW has been added to Porcine Aortic Endothelial Cells. The acquisition of isotope‐edited NMR spectroscopic experiments, including 15N relaxation measurements, allowed a precise characterization of the in‐cell HPLW epitope recognized by VEGFR2. 相似文献
2.
G.P. Romanelli D. Bennardi D.M. Ruiz G. Baronetti H.J. Thomas 《Tetrahedron letters》2004,45(48):8935-8939
Substituted coumarins are synthesized from phenols and β-ketoesters by the Pechmann reaction, using a Wells-Dawson heteropolyacid (H6P2W18O62·24H2O) as catalyst by a solvent-free procedure. This one requires low reaction times, 130 °C temperature and as little as 1 mol % of Wells-Dawson acid, obtaining good to excellent yields of coumarins. The catalyst showed to be reusable with no differences in the yields. The results are compared with those of the reactions performed in toluene solution. The presented synthetic procedure is a convenient, clean and fast alternative for synthesizing 4-substituted coumarins (17 examples). 相似文献
3.
A method for detecting carbonate in marine solid samples (sediments, corals) by Fourier transform infrared spectroscopy (FTIR) coupled to the total attenuated reflectance (ATR) technique is described. Compared to other techniques, the proposed method is not based on the measurement of CO2 evolved by combustion or acidification of the sample, but on the direct measurement of carbonate present in the sample. For this reason, the method by FTIR-ATR spectroscopy does not require any chemical pre-treatment. The proposed method allows determination of carbonate in the range 6-100% (w/w) as Na2CO3 and gives comparable results with the determination of inorganic carbon by elemental analysis. 相似文献
4.
Deerenberg S Schrekker HS van Strijdonck GP Kamer PC van Leeuwen PW Fraanje J Goubitz K 《The Journal of organic chemistry》2000,65(16):4810-4817
A series of chiral phosphine-phosphite ligands 1-6 have been synthesized and used in the enantioselective palladium-catalyzed reaction of rac-1,3-diphenyl-2-propenyl acetate with dimethyl malonate as nucleophile. Ligands 1a, 2, 3, 5a, 6a, and 6b have been synthesized starting from racemic tert-butylphenylphosphinoborane. The use of dynamically resolved Li phosphide (-)-sparteine provided the optically pure ligands. Crystals of the allylpalladium (6a) complex were obtained, suitable for X-ray crystal structure determination. The X-ray crystal structure of the allylpalladium (6a) complex revealed a longer palladium-carbon bond distance trans to the phosphine moiety indicating that the attack of the nucleophile takes place at the carbon trans to the phosphine moiety. This was confirmed by the fact that the phosphine moiety did not affect the enantioselectivity directly. Under mild reaction conditions, enantioselectivities up to 83% were obtained (25 degrees C) with ligand 1e. Systematic variation of the ligand bridge and the phosphite moiety showed that the configuration of the product is controlled by the atropisomerism of the biphenyl substituent at the phosphite moiety. The conformation of the biphenyl group, in turn, is controlled by the substituent at the chiral carbon in the bridge. Ligands with large bite angles yielded higher enantioselectivities. 相似文献
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At S-band (≈ 3 GHz) the modulation amplitude of the Electron Spin Echo patterns is increased with respect to the amplitude at X-band: as a consequence, it is possible to reveal the presence of nuclei not detectable at X-band. In this paper the results obtained by running ESE experiments at S-band on a C60 powder sample containing radicals are shown and discussed. The two- and three-pulse Electron Spin Echo patterns exhibit both13C modulation and proton modulation not detected at X-band. The experimental data are quantitatively analyzed by simulating the time-domain patterns and their Fourier transforms. It results that a noticeable amount of proton nuclei surrounds the intrinsic paramagnetic centers. On the basis of the analysis, a possible explanation of their existence is given. 相似文献
7.
Gardolinski JE Ramos LP de Souza GP Wypych F 《Journal of colloid and interface science》2000,221(2):284-290
Well-crystallized kaolinite (K) was initially reacted at 60 degrees C with a water/dimethylsulfoxide (DMSO) mixture and the resulting intercalation derivative (K-DMSO) was characterized by powder X-ray diffractometry (PXRD), thermal analysis (simultaneous TG and DSC), and Fourier-transformed infrared spectroscopy (FTIR). Benzamide crystals were then melted with the K-DMSO derivative at 140 degrees C for 4 days, when a gradual displacement of DMSO by benzamide was observed within the interlayer spacing of the modified kaolinite. The resulting material, after extensive washing with acetone, was characterized and compared to the results obtained previously for the K-DMSO composite. Benzamide intercalation proceeded by gradual displacement of DMSO molecules until completion. The structural stabilization of the K-BZ derivative was explained through the establishment of hydrogen bonds between the carbonyl oxygen atoms of the intercalated benzamide and aluminol groups present at the surface of the kaolinite layer. The interlamellar spacing of K-BZ was shown to be possibly occupied by benzamide molecules that were located at a 68 degrees orientation in relation to the layer surface. Unlike most intercalation molecules such as DMSO, variations in the interplanar spacing of kaolinite were consistent with the nonkeying of any other part of the molecule between the aluminosilicate interlayers. Copyright 2000 Academic Press. 相似文献
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Gregory B. Kharas Sonia E. Chavez Harrison S. Browning Jennifer A. Sepe Mario E. Romanelli Melissa K. Susnis 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):751-755
Electrophilic trisubstituted ethylenes, ring-disubstituted methyl 2-cyano-3-phenyl-2-propenoates, RPhCH?C(CN)CO2CH3, where R is 2,5-dichloro, 3,5-dichloro, 2,3-difluoro, 3-chloro-2-fluoro, 3-chloro-4-fluoro, 4-chloro-3-fluoro, 2-chloro-5-nitro, and 2-chloro-6-nitro were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-disubstituted benzaldehydes and methyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C-NMR. All the ethylenes were copolymerized with styrene (M1) in solution with radical initiation (ABCN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r1) for the monomers is 4-Cl-3-F (4.87) > 2,3-F2 (4.49) > 3-Cl-4-F (3.50) > 3-Cl-2-F (2.96) > 2-Cl-5-NO2 (2.02) > 2,5-Cl2 (1.54) > 2-Cl-6-NO2 (1.00) > 3,5-Cl2 (0.41). Relatively high Tg of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500ºC range with residue (1.5–34.5% wt), which then decomposed in the 500-800ºC range. 相似文献