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41.
42.
An automated analyzer for vancomycin in rat plasma by column-switching high-performance liquid chromatography (HPLC) with UV detection was developed. The method includes in-line extraction of vancomycin by ion-exchange cartridge column and a separation on a reversed-phase column with UV detection at 215 nm. Plasma samples were diluted by mobile phase solution and directly injected to HPLC. Vancomycin was quantitatively recovered from rat plasma samples. The separation was completed within 15 min. The calibration curve was linear over the range from 0.5 to 100 microg/mL with the detection and quantification limits of 0.5 microg/mL (2.5 ng on column; signal-to-noise ratio = 3). The values of precision in intra- and inter-day assays (n = 3) were less than 1.92 and 3.69%, respectively. This method does not require time-consuming pre-treatment and is suitable for the routine assay of plasma samples. 相似文献
43.
Y. Saito-Kokubu K. Yasuda M. Magara Y. Miyamoto S. Sakurai S. Usuda H. Yamazaki S. Yoshikawa 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(1):183-186
In order to know the distribution of plutonium derived from the Nagasaki atomic bomb, soil samples were measured to determine
the 240Pu/239Pu isotope ratio of and concentrations of 239+240Pu and 137Cs. The 239+240Pu concentrations in soils, except for Nishiyama area, were close to the average concentration of soil collected in Japan.
In soils collected at the Nishiyama area and at the eastern area of Nagasaki Prefecture and at part of northern area in Kumamoto
Prefecture, the 240Pu/239Pu ratios were lower than the global fallout values. This suggests that plutonium from the atomic bomb was deposited in the
eastern area from the hypocenter reaching up to 100 km eastwards. 相似文献
44.
Toshima K Jyojima T Miyamoto N Katohno M Nakata M Matsumura S 《The Journal of organic chemistry》2001,66(5):1708-1715
A highly stereoselective total synthesis of the macrolide antibiotic concanamycin F (1), a specific and potent inhibitor of vacuolar H(+)-ATPase, has been achieved by a convergent route involving the synthesis and coupling of its 18-membered tetraenic lactone and beta-hydroxyl hemiacetal side chain subunits. The C1-C19 18-membered lactone aldehyde 4 was synthesized through the intermolecular Stille coupling of the C5-C13 vinyl iodide 24 and the C14-C19 vinyl stannane 25, followed by construction of the C1-C4 diene and macrolactonization. Synthesis of 4 via a second convergent route including the esterification of the C1-C13 vinyl iodide 45 and the C14-C19 vinyl stannane 47 followed by the intramolecular Stille coupling was also realized. The highly stereoselective aldol coupling of 4 and the C20-C28 ethyl ketone 5 followed by desilylation provided 1 which was identical with natural concanamycin F. 相似文献
45.
L. Renee Ruhaak Sandra L. Taylor Suzanne Miyamoto Karen Kelly Gary S. Leiserowitz David Gandara Carlito B. Lebrilla Kyoungmi Kim 《Analytical and bioanalytical chemistry》2013,405(14):4953-4958
Many studies focused on the discovery of novel biomarkers for the diagnosis and treatment of disease states are facilitated by mass spectrometry-based technology. HPLC coupled to mass spectrometry is widely used; miniaturization of this technique using nano-liquid chromatography (LC)-mass spectrometry (MS) usually results in better sensitivity, but is associated with limited repeatability. The recent introduction of chip-based technology has significantly improved the stability of nano-LC-MS, but no substantial studies to verify this have been performed. To evaluate the temporal repeatability of chip-based nano-LC-MS analyses, N-glycans released from a serum sample were repeatedly analyzed using nLC-PGC-chip-TOF-MS on three non-consecutive days. With an average inter-day coefficient of variation of 4 %, determined on log10-transformed integrals, the repeatability of the system is very high. Overall, chip-based nano-LC-MS appears to be a highly stable technology, which is suitable for the profiling of large numbers of clinical samples for biomarker discovery. 相似文献
46.
Cross‐Coupling of Organolithium with Ethers or Aryl Ammonium Salts by C−O or C−N Bond Cleavage 下载免费PDF全文
Ze‐Kun Yang Dong‐Yu Wang Hiroki Minami Hiroyuki Ogawa Takashi Ozaki Dr. Tatsuo Saito Dr. Kazunori Miyamoto Dr. Chao Wang Prof. Dr. Masanobu Uchiyama 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(44):15693-15699
Various aryl‐, alkenyl‐, and/or alkyllithium species reacted smoothly with aryl and/or benzyl ethers with cleavage of the inert C?O bond to afford cross‐coupled products, catalyzed by commercially available [Ni(cod)2] (cod=1,5‐cyclooctadiene) catalysts with N‐heterocyclic carbene (NHC) ligands. Furthermore, the coupling reaction between the aryllithium compounds and aryl ammonium salts proceeded under mild conditions with C?N bond cleavage in the presence of a [Pd(PPh3)2Cl2] catalyst. These methods enable selective sequential functionalizations of arenes having both C?N and C?O bonds in one pot. 相似文献
47.
48.
49.
Yoshiaki Miyamoto Norihiro Wada Dr. Takahiro Soeta Dr. Shuhei Fujinami Prof. Dr. Katsuhiko Inomata Prof. Dr. Yutaka Ukaji 《化学:亚洲杂志》2013,8(4):824-831
The stereoselective direct transformation of N‐(propargylic)hydroxylamines into cis‐2‐acylaziridines was achieved by the combined use of AgBF4 and CuCl. Copper salts were found to promote the transformation of the intermediary 4‐isoxazolines into 2‐acylaziridines and both 3‐aryl‐ and 3‐alkyl‐substituted 2‐acylaziridines could be prepared by using this method. Furthermore, subsequent 1,3‐dipolar cycloaddition of azomethine ylides that were generated in situ from the intermediary 2‐acylaziridines with maleimides was achieved in a stereoselective one‐pot procedure to afford the corresponding 2‐acylpyrrolidines, which consisted of an octahydropyrrolo[3,4‐c]pyrrole skeleton. 相似文献
50.