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91.
Design of Ratiometric Fluorescent Probes Based on Arene–Metal‐Ion Interactions and Their Application to CdII and Hydrogen Sulfide Imaging in Living Cells
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Ippei Takashima Miyuki Kinoshita Ryosuke Kawagoe Saika Nakagawa Prof. Dr. Manabu Sugimoto Prof. Dr. Itaru Hamachi Prof. Dr. Akio Ojida 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(8):2184-2192
Non‐coordinative interactions between a metal ion and the aromatic ring of a fluorophore can act as a versatile sensing mechanism for the detection of metal ions with a large emission change of fluorophores. We report the design of fluorescent probes based on arene–metal‐ion interactions and their biological applications. This study found that various probes having different fluorophores and metal binding units displayed significant emission redshift upon complexation with metal ions, such as AgI, CdII, HgII, and PbII. X‐ray crystallography of the complexes confirmed that the metal ions were held in close proximity to the fluorophore to form an arene–metal‐ion interaction. Electronic structure calculations based on TDDFT offered a theoretical basis for the sensing mechanism, thus showing that metal ions electrostatically modulate the energy levels of the molecular orbitals of the fluorophore. A fluorescent probe was successfully applied to the ratiometric detection of the uptake of CdII ions and hydrogen sulfide (H2S) in living cells. These results highlight the utility of interactions between arene groups and metal ions in biological analyses. 相似文献
92.
Kenji Yoshikawa Miki Shimizu Toshiro Matsumura Akio Sakuragawa 《International journal of environmental analytical chemistry》2018,98(8):789-798
Capillary zone electrophoresis with indirect UV detection was developed for the simultaneous analysis of inorganic anions and organic acids using a mixed solution of 2,6-pyridinedicarboxylic acid and cetyltrimethylammonium hydroxide as the background electrolyte (BGE). The parameters which influence the separation, such as indirect UV detection wavelength, BGE conditions, applied voltage and extraction conditions were investigated. Thirteen inorganic anions and organic acids were detected within 20 min. The calibration curves of each analyte were linear with correlation coefficients greater than 0.991. The relative standard deviations (n = 10) of the peak areas ranged from 0.6% to 3.3%. The detection limits for these species ranged from 0.4 to 1.4 mg/L at a signal-to-noise ratio of 3. The recovery rate of each analyte was more than 80% under optimised extraction conditions, except for nitrite. The proposed method was applied towards the analysis of inorganic anions and organic acids in the atmospheric particulate matter using an Andersen sampler. The particle size of the particulate matter was determined, but not the size of the anions. 相似文献
93.
Kenshu Fujiwara Masanori Kobayashi Fuyuki Yamamoto Yu-ichi Aki Mariko Kawamura Daisuke Awakura Seiji Amano Azusa Okano Akio Murai Hidetoshi Kawai Takanori Suzuki 《Tetrahedron letters》2005,46(30):5067-5069
The common left-half [C31-C33(OC1-C7)-C40] part of pectenotoxins has been synthesized convergently from the C31-C35, C36-C40, and C1-C7 parts. The C31-C35 part, prepared via a new route shorter than our previous route, was coupled with the C36-C40 part through reductive lithiation and addition reactions to give an adduct stereoselectively, which was converted to a cyclic acetal corresponding to the C31-C40 part. The left-half was synthesized by a three-step process including esterification of the C31-C40 part with the C1-C7 part. 相似文献
94.
Akio Saito 《Tetrahedron letters》2007,48(39):6852-6855
Cationic rhodium(I) catalyst derived from [RhCl(cod)]2 and AgSbF6 in hexafluoroisopropanol (HFIP) efficiently catalyzed the formation of bicyclic pyridine derivatives by intramolecular hetero-[4+2] cycloadditions of ω-alkynyl-vinyl oximes. 相似文献
95.
Rate constant measurements for initial addition reactions of radicals at the propagation step of photo‐polymerization as studied by pulsed EPR spectroscopy
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Yusuke Miyake Yutaka Marushima Hirona Takahashi Nobuyuki Akai Kazuhiko Shibuya Akio Kawai 《Journal of Physical Organic Chemistry》2016,29(9):468-475
Pulsed EPR spectroscopy was employed to determine reaction rate constants at an early stage of addition reactions in radical polymerizations triggered by four initiator radicals, which were generated by photodissociation of four parent molecules. Two monomers (tert‐butylacrylate and tert‐butylmethacrylate) were examined as reactant. Stern–Volmer analysis on the measured decay time of electron spin echo intensity of reacting radicals provides rate constants for addition reactions. We focused on rate constants for the second step reaction between monomer and adduct radical that is produced by the first step addition reaction between initiator radical and monomer. The rate constant measured by pulsed EPR was evaluated by theoretical calculations in the light of (1) enthalpy difference between product radical and reactants and (2) charge transfer interaction between reacting radical and monomer. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
96.
97.
Hisanori Yamane Ryouji Tanimura Junichi Takahashi Masahiko Shimada 《Journal of solid state chemistry》2006,179(1):289-295
New compounds CaY2Ge3O10 and CaY2Ge4O12 were prepared by heating mixtures of CaCO3, Y2O3 and GeO2 at 1200 °C. CaY2Ge3O10 is stable at 1300 °C, while CaY2Ge4O12 decomposes into a melt and CaY2Ge3O10 at approximately 1250 °C. We obtained single crystals of CaY2Ge3O10 by cooling a sample with an initial composition of Ca:Y:Ge=1:2:8 from 1300 °C with a rate of −6 °C/h. The crystal structure of CaY2Ge3O10 was determined by single crystal X-ray diffraction. CaY2Ge3O10 crystallizes in the monoclinic space group P21/c with a=6.0906(8), b=6.8329(8), and β=109.140(3)°, Z=4, and R1=0.029 for I>2σ(I). In the structure of CaY2Ge3O10, Ca and Y atoms are situated disorderly in three 7-fold coordination sites between isolated germanate groups of triple GeO4 tetrahedra, Ge3O10. The structural formula of CaY2Ge3O10 is expressed as (Ca0.45Y0.55)(Ca0.46Y0.54)(Ca0.09Y0.91)Ge3O10. The crystal structure of CaY2Ge4O12 was analyzed by the Rietveld method for the X-ray powder diffraction pattern. CaY2Ge4O12 is isotypic with SrNa2P4O12, crystallizing in the orthorhombic space group P4/nbm, a=9.99282(6), , Z=2, Rwp=0.092, Rp=0.067. CaY2Ge4O12 contains four-membered GeO4-tetrahedra rings, Ge4O12. Eight-fold coordinated square-anitiprism sites and 6-fold octahedral sites between the layers of the Ge4O12 rings are occupied by Y atom and Ca/Y atoms, respectively The structural formula is Y(Ca0.5Y0.5)2Ge4O12. 相似文献
98.
Ming-Qing Chen Takeshi Serizawa Akio Kishida Mitsuru Akashi 《Journal of polymer science. Part A, Polymer chemistry》1999,37(13):2155-2166
Monodisperse polymeric nanospheres, which consist of polystyrene cores and poly(ethylene glycol) (PEG) branches on their surfaces, were prepared by the dispersion copolymerization of styrene (St) with PEG macromonomers that had a methacryloyl (MMA-PEG) or p-vinylbenzyl (St-PEG) end group in various organic solvent/water media. Electron spectroscopy for chemical analysis (ESCA) of the nanosphere surfaces indicated that PEG macromonomer chains were favorably located on their surfaces. The morphologies of the nanospheres were observed via a scanning electron micrograph (SEM), and particle sizes were estimated by a submicron particle analyzer. When both the concentration of macromonomers and molecular weight were higher, small nanospheres in diameter were obtained. Larger nanospheres in diameter were obtained using macromonomers with low molecular weight at lower concentration. The functions that correlate the diameter (Dn) on different concentration units were Dn = K[St]0.64[MMA-PEG]−0.53±0.01[I]−0.49 and Dn = K[St]0.80[St-PEG]−0.69±0.01[I]−0.22, where [I], [St], [MMA-PEG], and [St-PEG] are initiator, styrene, MMA-PEG, and St-PEG macromonomer concentration in feed, respectively. When the reaction parameters such as the molecular weight of the macromonomers were properly chosen, the particle size could be controlled in a range from ca. 80 to 3100 nm. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2155–2166, 1999 相似文献
99.
Ojida A Mito-Oka Y Inoue MA Hamachi I 《Journal of the American Chemical Society》2002,124(22):6256-6258
The first fluorescent chemosensors toward a native phosphorylated peptide are successfully synthesized. Dinuclear zinc(II)-dipicolylamine-based anthracene (1, 2) can selectively recognize and sense phosphorylated species with an increase in the fluorescence intensity. We also demonstrated that these artificial receptors fluorometrically detect a phosphorylated peptide with high affinity (>107 M-1) in aqueous solution. 相似文献
100.