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1.
Marilyn M. Olmstead James C. Fettinger Soya Gamsey Jacob W. Clary Bakthan Singaram 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(6):o333-o335
The structures of three chiral vinyldioxazaborocanes are reported, namely (2E)‐ and (2Z)‐6‐benzyl‐2‐buten‐2‐yl‐1,3,6,2‐dioxazaborocane, C27H30BNO2, (II) and (III), respectively, and (2Z)‐2‐buten‐2‐yl‐6‐isobutyl‐1,3,6,2‐dioxazaborocane, C24H32BNO2, (IV). These compounds may be useful in asymmetric reactions. In the structures reported here, the N—B donor–acceptor bond is longer than in any previously reported analogous compounds. 相似文献
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Gamsey S Miller A Olmstead MM Beavers CM Hirayama LC Pradhan S Wessling RA Singaram B 《Journal of the American Chemical Society》2007,129(5):1278-1286
Several novel diboronic acid-substituted bipyridinium salts were prepared and, using a fluorescent reporter dye, were tested for their ability to selectively bind various monosaccharides and alpha-hydroxycarboxylates in an aqueous medium. The fluorescence sensing mechanism relies on the formation of a ground-state charge-transfer complex between the dye and bipyridinium. An X-ray crystal structure of this complex is described herein. Glucose selectivity over fructose and galactose was achieved by designing the bipyridinium-based receptors to be capable of attaining a 1:1 receptor/substrate stoichiometry via cooperative diboronic acid binding. 相似文献
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Gamsey S Suri JT Wessling RA Singaram B 《Langmuir : the ACS journal of surfaces and colloids》2006,22(21):9067-9074
A fluorescent anionic dye and a viologen appended with boronic acids, which serve as glucose receptors, have been synthesized and immobilized into a poly(2-hydroxyethyl methacrylate) hydrogel for use as a continuous glucose monitor. The fluorescence of the dye is modulated by the quenching efficiency of the viologen-based receptor, which in turn is dependent on the glucose concentration. Two monomeric versions of the quencher/receptor unit were prepared and their performance within the hydrogel evaluated. By tethering the quencher/receptor to the hydrogel matrix using a single-point attachment, slightly improved glucose sensing was observed. The hydrogels were tested for their ability to continuously and reversibly detect glucose over the course of several hours. The tests were carried out using a cuvette-based system, as well as a fiber-optic-based configuration. Under physiological conditions (0.1 M phosphate buffer, pH 7.4, 37 degrees C), the fluorescent hydrogels display an excellent dynamic response to glucose concentrations within the biologically significant range (2.5-20 mM). 相似文献
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T Kamei H Seto K Taki T Soya M Kakishita M Maeda T Honda S Koshimura 《Radioisotopes》1987,36(1):14-19
To compare accumulation of the 125I-labeled antibodies (anti-carcinoembryonic antigen (CEA) monoclonal antibody and polyclonal antibody) to a CEA-producing tumor (SC-2-JCK), an in vivo localization study was performed in nude mice. The tumor-to-blood ratio at 120 hours after injection rose to 4.6 for the monoclonal antibody, but remained at 1.3 for the polyclonal antibody. However, no differences were noted between the antibodies up to 72 hours after injection. In autoradiograms, selective accumulation of the tracer was noted in the tumor for both antibodies. However, no superiority or inferiority of imaging for either of the antibodies could be definitely determined. 相似文献
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Wei Zhou Soya Inoue Takashi Iwahashi Kaname Kanai Kazuhiko Seki Takayuki Miyamae Doseok Kim Yasushi Katayama Yukio Ouchi 《Electrochemistry communications》2010,12(5):672-675
The electrochemical interface between a polycrystalline Pt electrode and the ionic liquid 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim][OTf]) has been studied by in-situ IR-visible sum-frequency generation (SFG) spectroscopy. Potential dependent adsorption/desorption processes of OTf anions has been monitored within the electrochemical window. SFG results indicate that the ions form a double layer structure at the interface. Significant adsorption/desorption hysteresis has been observed for the anions on the Pt surface. 相似文献
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Nian Sun Naoto Soya Elena N. Kitova John S. Klassen 《Journal of the American Society for Mass Spectrometry》2010,21(3):472-481
An investigation of the nonspecific association of small charged biomolecules and proteins in electrospray ionization mass
spectrometry (ES-MS) is described. Aqueous solutions containing pairs of proteins and a small acidic or basic biomolecule
that does not interact specifically with either of the proteins were analyzed by ES-MS and the distributions of the biomolecules
bound nonspecifically to each pair of proteins compared. For the basic amino acid arginine and the peptide RGVFRR, nonequivalent
distributions were measured in positive ion mode, but equivalent distributions were measured in negative ion mode. In the
case of uridine 5′-diphosphate, nonequivalent distributions were measured in negative ion mode, but equivalent distributions
observed in positive ion mode. The results of dissociation experiments performed on the gaseous ions of the nonspecific complexes
suggest that the nonequivalent distributions result from differences in the extent to which the nonspecific complexes undergo
in-source dissociation. To test this hypothesis, the distributions of nonspecifically bound basic molecules measured in the
presence of imidazole, which protects complexes from in-source dissociation, were compared. In all cases, equivalent distributions
were obtained. The results indicate that nonspecific binding of charged molecules to proteins during ES is a statistical process,
independent of protein structure and size. However, the kinetic stabilities of the nonspecific interactions are sensitive
to the nature of the protein ions. It is concluded that the reference protein method for correcting ES mass spectra for nonspecific
ligand-protein binding can be applied to the analysis of ionic ligands, provided that in-source dissociation of the nonspecific
interactions is minimized. 相似文献
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[reaction: see text] Lithium aminoborohydride (LAB) reagents promote the amination of 2-fluoropyridine under mild reaction conditions, providing 2-(dialkylamino)pyridines in excellent yield and purity. Treatment of 2-fluoropyridine with 1.1 equiv of lithium aminoborohydride at room temperature affords complete conversion after 1 h. This is the first general way by which 2-(dialkylamino)pyridines may be directly obtained from fluoropyridines under ambient reaction conditions. 2-Chloropyridine can also be converted to 2-(dialkylamino)pyridine by simply increasing the number of LAB equivalents and the reaction temperature. 相似文献
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Kazuharu Sugawara Sora Ishizaki Soya Kikuchi Hideki Kuramitz Toshihiko Kadoya 《Electroanalysis》2021,33(4):975-986
A protein probe with an electron-transfer peptide and a His-tag was designed to electrochemically sense a target protein. We selected tyrosine-rich (Y4C) and tryptophan-rich (W4C) peptides for use as electron-transfer agents. The peak for oxidation was based on the oxidations of the phenolic hydroxy groups in Y4C and on the indole rings in W4C. Asialofetuin (ASF) with galactose residues was the protein probe, and a galactose recognition protein, soybean agglutinin (SBA), was the target protein. A protein probe composed of an amino acid and carbohydrate residue was expected to be biocompatible. When voltammetric measurements were performed using a glassy carbon electrode, the oxidation peaks of H6Y4C and ASF-H6Y4C appeared at the same potential. The peak current of ASF-H6Y4C was 4-fold that of H6Y4C because of the stronger adsorption of ASF-H6Y4C onto the electrode. The electrode response of ASF-H6Y4C with SBA was half that of ASF-H6Y4C alone. By contrast, the peak current of ASF-Y4CH6 was higher than that of ASF-H6Y4C, which was the result of a greater degree of contact between the Y4C moieties and an electrode. On the other hand, the voltammetric behaviors of ASF with W4C and a His-tag were similar to those with Y4C and a His-tag. The sensitivity of SBA using ASF-Y4CH6 was at the 10−13 M level. To confirm the function of the sensing system, measurements were performed in human serum with SBA and ASF-Y4CH6. When SBA was added, the serum had a concentration that ranged between 5.0×10−13 and 4.0×10−12 M, and the amount of SBA that could be recovered ranged from 97 to 101%. Consequently, this system could be applied to the detection of SBA in serum. 相似文献