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31.
Hideyuki Yoshida Junichiro Sonoda Junichi Ishida Masatoshi Yamaguchi 《Analytica chimica acta》2005,534(2):177-183
A simple screening method of organic aciduria by spectrofluorometric measurement of total dicarboxylic acids in human urine is described. This method is based on an intramolecular excimer-forming fluorescence derivatization with a pyrene reagent, 4-(1-pyrene)butanoic acid hydrazide (PBH). Dicarboxylic acids in urine were converted to the corresponding dipyrene-labeled derivatives by reaction with PBH in the presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and pyridine, and the derivatives afforded intramolecular excimer fluorescence (420-540 nm) which can clearly be discriminated from the normal fluorescence (360-420 nm) emitted from reagent blanks. The technique is so selective that it permits spectrofluorometric measurement of total amount of dicarboxylic acids by the direct derivatization of diluted urine samples. The same reaction mixture has also served as a liquid chromatographic (LC) sample for the separative determination of individual dicarboxylic acids. The spectrofluorometric data did not contradict with the LC data. These methods were usefully applied to preliminary screening test of glutaric aciduria. In conclusion, the present derivatization method allows rapid and direct determination of total amount of dicarboxylic acids in human urine samples. 相似文献
32.
Three new metabolites, kunzeanones A (1), B (2), and C (3), along with three known compounds, cryptostrobin (4), (+)-spathulenol (5), and (−)-globulol (6), were isolated from the non-polar fraction of the dried leaves of Kunzea ambigua (Myrtaceae), which shows ichthyotoxicity toward a small fish, medaka. The structures of these new compounds were elucidated as condensates of alkylated phloroglucinol with methylflavanone and germacrane-type sesquiterpene, respectively, on the basis of spectral analyses including 1-D and 2-D NMR spectra. The stereochemistries of kunzeanones A and B were determined by X-ray crystallographic analysis. A sesquiterpene, (+)-spathulenol (5), among the isolates was characterized as the ichthyotoxic principle of the extract. 相似文献
33.
Supawan Joonwichien Eiji Yamasue Hideyuki Okumura Keiichi N. Ishihara 《Applied magnetic resonance》2012,42(1):17-28
Magnetic field effects (MFEs) on photocatalytic degradation of methylene blue (MB) solution over ZnO and TiO2 powders are investigated under static magnetic field up to 0.7 T with light irradiation by ultraviolet (UV) light emitting
diode. The UV–visible-near-infrared spectrometer is used to monitor the MB concentrations. The positive MFE is observed for
ZnO, while the negative MFE for TiO2, and both MFEs are increased with the increase in the magnetic field applied. By increasing the settling time (the time interval
between the preparation of MB solution and the powder dispersion into the MB solution), the photodegradation abilities under
MFEs are decreased for both the catalysts. The cause of MFE is discussed in terms of dissolved oxygen in the MB solution and
magnetic adsorption of the constituent molecules. 相似文献
34.
35.
Fujiko Iwasaki Hideyuki Nishiyama Noriko Manabe Masanori Yasui Noboru Matsumura 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):429-430
Abstract Novel metal-carbene complexes (4) with a metallapentalene framework have been obtained from hypervalent diazadiselenathiapentalenes (3) by treating with Pt(PPh3)4, Pd(PPh3)4 and RhCl(PPh3)3. X-Ray investigations revealed that the central hypervalent sulfur atom in 3 was substituted by a metal atom to form M-Se bonds in the resultant metallapentalene framework. 相似文献
36.
Toshio Shimizu Kazuko Iwata Hideyuki Murakami Nobumasa Kamigata 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):457-458
Sulfur-containing cycloalkenes possessing disulfide units 1, 2, and 3 were obtained by oxidation of cis-disodium ethene-1,2-dithiolate, and their crystal structures were determined by the X-ray crystallographic analyses. Compound 1 was found to give the ring expansion product 3 in acetonitrile even at room temperature and also form reactive thioaldehyde under irradiation. 相似文献
37.
Tatsunori Iwamura Takashi Ichikawa Hiroshi Shimizu Tadashi Kataoka 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):471-472
Abstract Reactions of thiazolo[3,2-b]-1,2,4-triazolium N-methylides with electron-deficient acetylenes gave the thiazole ring-opened products as a mixture of the E-and Z-isomers. In contrast, the N-phenacylides reacted with dimethyl acetylenedicarboxylate to give the thiobenzoates together with the thiazole ring-opened products. The mechanism for formation of these compounds is described. 相似文献
38.
Kenichiro Todoroki Hiroki Hashimoto Kazuyuki Machida Miki Itoyama Tadashi Hayama Hideyuki Yoshida Hitoshi Nohta Manabu Nakashima Masatoshi Yamaguchi 《Journal of separation science》2013,36(2):232-238
In this study, we combined a column‐switching system with a fluorous scavenging derivatization method to develop a fully automated reagent peak‐free LC fluorescence detection protocol for the analysis of highly polar carboxylic acids. In this method, highly polar carboxylic acids were derivatized with fluorescent 1‐pyrenemethylamine in the presence of 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide and 1‐hydroxy‐1H‐benzotriazole. Residual excess of the unreacted reagent was tagged with 2‐(perfluorooctyl)ethyl isocyanate and then removed selectively using a fluorous column‐switching system placed in front of an analytical reversed‐phase column. The signal of the fluorous‐tagged unreacted reagent was completely absent in the resulting chromatograms; therefore, it did not interfere with the quantification of each acid especially those eluted before 20 min. The detection limits (S/N = 3) for the examined acids were in the range from 4.0 to 22 fmol per injection. We have applied this method to comparative analysis of highly polar carboxylic acids in urine samples obtained from diabetes mellitus type‐II model mice and their control. 相似文献
39.
Satoshi Kaneco Kensuke Hayashi Hideyuki Katsumata Tohru Suzuki 《International journal of environmental analytical chemistry》2013,93(13):1381-1388
A preconcentration method by adsorption of cadmium on a niobium wire was developed for the environmental waters, followed by electrothermal atomic absorption spectrometry with a tungsten tube atomizer. After the preconcentration, the niobium wire was directly inserted into the tungsten tube atomizer. In the preconcentration (adsorption) process of cadmium, the optimal immersing time was 60?s. The effects of large amounts of concomitants on the preconcentration of cadmium were evaluated. When 103–104 fold excess of matrix elements existed in aqueous solution at pH 4 and 9, the cadmium response was profoundly affected by the matrix elements. However, the cadmium absorption signal was not significantly influenced at pH 7. Therefore, pH 7 was selected for the application into the real environmental samples. Under the optimal conditions, the detection limit (3S/N) for cadmium by the niobium wire preconcentration method was 7.0?pg?mL?1 and the relative standard deviation was 6.8%. The method with preconcentration on a niobium wire was applied to the determination of cadmium in water and proved to be sensitive, simple and convenient. Because this preconcentration method can be utilized in the in situ treatment of trace cadmium in environmental water samples, it was unnecessary to carry the water samples to the analytical work place. The technique was shown to be useful for the determination of cadmium in environmental water samples at 0.1–1?µg?L?1 levels. 相似文献
40.
Synthesis,Crystal Packing,and Ambipolar Carrier Transport Property of Twisted Dibenzo[g,p]chrysenes 下载免费PDF全文
Dr. Yasuyuki Ueda Dr. Hayato Tsuji Dr. Hideyuki Tanaka Prof. Dr. Eiichi Nakamura 《化学:亚洲杂志》2014,9(6):1623-1628
A versatile method for the synthesis of dibenzo[g,p]chrysene (DBC) derivatives based on regio‐ and stereoselective stannyllithiation to diarylacetylenes is described. This method affords a variety of DBCs possessing both electron‐donating and electron‐withdrawing functional groups. These twisted molecules take brickwork packing structures in single crystals. Thus, ambipolar carrier transport properties with mobility values of up to 10?3 cm2 V?1 s?1 in the amorphous state were achieved. Functional groups on DBC frameworks are considered to increase carrier mobility through the enhancement of intermolecular interactions in the brickwork packing structures. 相似文献