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101.
Suzuki T Horie Y Koike K Satake M Oshima Y Iwataki M Yoshimatsu S 《Journal of chromatography. A》2007,1142(2):172-177
Several strains of Protoceratium reticulatum, one of the dinoflagellates producing yessotoxins (YTXs), were collected from various shellfish producing areas in Japan. YTXs in the cultured strains were analyzed by liquid chromatography-mass spectrometry (LC-MS). Neutral loss scan monitoring, multiple reaction monitoring (MRM) for more than 20 YTX analogues, and full-scan MS/MS spectra obtained with a hybrid triple quadrupole/linear ion trap mass spectrometer showed that yessotoxin (YTX), 45,46,47-trinoryessotoxin (trinorYTX), 1-homoyessotoxin (homoYTX), and 45,46,47-trinor-1-homoyessotoxin (trinor-1-homoYTX) were the dominant toxins in these strains of P. reticulatum. Enone isomer of 42,43,44,45,46,47,55-heptanor-41-oxoyessotoxin (noroxoYTX enone) was also detected in some strains. Toxin profiles and contents were different among the strains. Some strains produced YTX, trinorYTX, 1-homoYTX, trinor-1-homoYTX, and noroxoYTX enone, whereas other strains produced only YTX or 1-homoYTX. This is the first identification of 1-homoYTX and noroxoYTX enone in P. reticulutum in Japan. Some strains did not produce any detectable YTX analogues. 相似文献
102.
Nobuo Yamada Dr. Hiroki Noguchi Yoshifumi Orimoto Dr. Yutaka Kuwahara Prof. Dr. Makoto Takafuji Shaheen Pathan Dr. Reiko Oda Almara Mahammadali Rahimli Prof. Dr. Mahammadali Ahmed Ramazanov Prof. Dr. Hirotaka Ihara 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(43):10141-10148
In this work, a new class of totally organic fluorescent nanogel particles and their exceptionally specific behaviors based on their unique structures are introduced, which draws a sharp line from conventional fluorophore-doped and fluorophore-branched-type particles. The nanogel particles, the diameter of which could be controlled by adjusting reaction conditions, such as the solvent system, were spontaneously fabricated with a spherical shape by direct polymerization of non-heterocyclic aromatic compounds, such as 2,6-dihydroxyanthracene, 2,6-dihydroxynaphthalene, and 9,9-bis(4-hydroxyphenyl)fluorene with triazinane as the cross-linker. A fluorophoric moiety formed from a polymer main chain was realized in the particle, and consequently, the resultant content of the fluorophoric moiety was around 70–80 wt % per particle. The uniqueness and versatility of the particles can be emphasized by their good compatibility with various solvents due to their amphiphilic and ampholytic swelling properties, but also by their remarkable fluorescent solvatochromism in the dispersion state. Furthermore, these behaviors were preserved even in their polymer composite system. This study also demonstrates that various fluorescent polymer films can be fabricated with emission color control due to memorization of the solvatochromism phenomenon of the dispersed fluorescent nanoparticles. 相似文献
103.
Aromatic aldehydes or ketones which have electron-withdrawing groups on the benzene ring were selectively reduced to the corresponding alcohols in good yields by sodium hydrogentelluride; common aldehydes such as benzaldehyde and tolualdehyde were inert. 相似文献
104.
Toshiyasu Inuzuka Yutaka Yamamoto Kaoru Yamada Daisuke Uemura 《Tetrahedron letters》2012,53(2):239-242
A polyol compound, amdigenol A, was isolated from the dinoflagellate Amphidinium sp. that adhered to the surface of the marine alga Digenea simplex. A structural elucidation was performed by 2D-NMR spectroscopy, degradation with a second generation Hoveyda–Grubbs catalyst and ESI-CID-MS/MS analyses. Amdigenol A consists of a C98-linear carbon backbone including two core structures of amphidinol analogs and is likely formed linearly by two amphidinol analogs. 相似文献
105.
We realize simultaneous quantum degeneracy in mixtures consisting of the alkali and alkaline-earth-like atoms Li and Yb. This is accomplished within an optical trap by sympathetic cooling of the fermionic isotope ?Li with evaporatively cooled bosonic 1??Yb and, separately, fermionic 1?3Yb. Using cross-thermalization studies, we also measure the elastic s-wave scattering lengths of both Li-Yb combinations, |a(?Li-1??Yb)| = 1.0 ± 0.2 nm and |a(?Li-1?3Yb)| = 0.9 ± 0.2 nm. The equality of these lengths is found to be consistent with mass-scaling analysis. The quantum degenerate mixtures of Li and Yb, as realized here, can be the basis for creation of ultracold molecules with electron spin degrees of freedom, studies of novel Efimov trimers, and impurity probes of superfluid systems. 相似文献
106.
Nicholas J. Turro Yoshifumi Tanimoto Gavriella Gabor 《Photochemistry and photobiology》1980,31(6):527-532
Abstract— The absorption and fluorescence spectra of two functional ionic detergents containing an indole chromophore have been studied as micelle probes and have been compared to the corresponding spectra of 1-methylindole. The quenching of the fluorescence of the probes by NO- 2 and Co2+ has also been investigated. Based on the results obtained, it is concluded that 1-methylindole is associated with the surface of HDTBr micelles, whereas it is located in the interior of SDS micelles. The chromophore of the indole detergents is considered to be located in the interior of HDTBr and SDS micelles. 相似文献
107.
108.
Nicolai E. Polyakov Masaharu Okazaki Yoshihisa Fujiwara Yoshifumi Tanimoto Haruhiko Fukaya 《Photochemistry and photobiology》1995,61(6):545-551
The electron spin resonance (ESR) spectra of the transient radical pairs in the photoreduction of 1,5-diphenyl-1,4-pentadiyn-3-one ( I ) and 1,3-diphenyl-2-propyn-1-one ( II ) in sodium dodecyl sulfate (SDS) micellar solutions have been obtained by using the product-yield-detected ESR (PYESR) technique. The PYESR spectra, detected by tracing the microwave effect on the spin-adduct yield as functions of the magnetic field, show the ESR spectra of the ketyl radical of the ketone and SDS radical as the components of the radical pairs. In addition, the growth and the decay processes of the radical pair were observed through detecting the effect of microwave pulse as functions of the delay period between a laser pulse and the off and on time, respectively, of a microwave pulse. The absorption spectra of transient species have also been obtained by using the laser flash photolysis technique. Through the analysis of these data and molecular orbital calculations, the role of acetylenic groups in the photoreactivity of acetylenic ketones is discussed. 相似文献
109.
Vanadium(V) is quantitatively precipitated from aqueous solution with 4-caprinoyl-3-methyl-1-phenyl-5-pyrazolone at pH 1, and collected as a film on a membrane for x-ray fluorescence spectrometry. The limit of detection is ca. 2 μg of vanadium. The procedure gave satisfactory results on standard steels containing 0.003–0.091% vanadium. 相似文献
110.
Stereochemically and functionally rich polycyclic compounds are obtained by the first crossed aldehyde-ketone benzoin reaction in excellent yield under mild reaction conditions (5-20 mol % thiazolium salt, 10-70 mol % DBU, tBuOH, 40 degrees C, 30 min). This novel catalytic methodology offers a convenient approach to sophisticated molecular architectures useful for the stereocontrolled construction of polycyclic compounds as well as the fully regiocontrolled synthesis of anthra- and naphthoquinones. 相似文献