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991.
Simultaneous determination of sarpogrelate and its active metabolite in human plasma by liquid chromatography with tandem mass spectrometry and its application to a pharmacokinetic study 下载免费PDF全文
Jung Bae Park Soo Kyung Bae Soo Hyeon Bae Euichaul Oh 《Journal of separation science》2015,38(1):42-49
We established a rapid and simple liquid chromatography with tandem mass spectrometry method for the simultaneous determination of sarpogrelate and its active metabolite, M‐1, in human plasma. Sarpogrelate, M‐1, and the internal standard, ketanserin, were extracted from a 50 μL aliquot of human plasma by protein precipitation using acetonitrile. Chromatographic separation was performed on a Shim‐pack GIS ODS C18 column (100 × 3.0 mm; 3 μm) with an isocratic mobile phase consisting of 10 mM ammonium acetate and acetonitrile (70:30, v/v) at a flow rate of 0.6 mL/min; the total run time was <2.5 min. Mass spectrometric detection was conducted in selected reaction‐monitoring mode with positive electrospray ionization at m/z 430.35 → 135.10 for sarpogrelate, m/z 330.30 → 58.10 for M‐1, and m/z 395.70 → 188.85 for ketanserin. The linear ranges of concentration for sarpogrelate and M‐1 were 1–1000 and 0.5–500 ng/mL, respectively. The coefficient of variation for the assay's precision was ≤9.95%, and the accuracy was 90.6–107%. All analytes were stable under various storage and handling conditions, and no relevant crosstalk and matrix effect was observed. This method was successfully applied to a pharmacokinetic study after oral administration of a 100 mg sarpogrelate tablet to healthy male Korean volunteers. 相似文献
992.
Nucleophilic Aromatic Substitution Reactions of meso‐Bromosubporphyrin: Synthesis of a Thiopyrane‐Fused Subporphyrin 下载免费PDF全文
Daiki Shimizu Hirotaka Mori Masaaki Kitano Won‐Young Cha Juwon Oh Dr. Takayuki Tanaka Prof. Dr. Dongho Kim Prof. Dr. Atsuhiro Osuka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(49):16194-16202
meso‐Bromosubporphyrin undergoes nucleophilic aromatic substitution (SNAr) reactions with arylamines, diarylamines, phenols, ethanol, thiophenols, and n‐butanethiol in the presence of suitable bases to provide the corresponding substitution products. The SNAr reactions also proceed well with pyrrole, indole, and carbazole to provide substitution products in moderate to good yields. Finally, the SNAr reaction with 2‐bromothiophenol and subsequent intramolecular peripheral arylation reaction affords a thiopyrane‐fused subporphyrin. 相似文献
993.
A Direct Hybridization between Isocharged Nanosheets of Layered Metal Oxide and Graphene through a Surface‐Modification Assembly Process 下载免费PDF全文
Kanyaporn Adpakpang Seung Mi Oh Xiaoyan Jin Prof. Dr. Seong‐Ju Hwang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15459-15466
An efficient and universal method to directly hybridize isocharged nanosheets of layered metal oxide and reduced graphene oxide (rGO) is developed on the basis of the surface modification and an electrostatically driven assembly process. On the basis of this synthetic method, the CoO2–rGO nanocomposite can be synthesized with exfoliated CoO2 and rGO nanosheets, and transformed into CoO–CoO2–rGO nanocomposites with excellent electrode performance for lithium‐ion batteries. Also, this surface‐modification assembly route is successfully applied for the synthesis of another mesoporous TiO2–rGO nanocomposite. This result provides clear evidence for the usefulness of the present method as a universal way of hybridizing isocharged anionic nanosheets of inorganic solids and graphene. 相似文献
994.
Nicky Chan Nathan Yee So Young An Jung Kwon Oh 《Journal of polymer science. Part A, Polymer chemistry》2014,52(14):2057-2067
New poly(ethylene oxide)‐based block copolymers (ssBCs) with a random copolymer block consisting of a reduction‐responsive disulfide‐labeled methacrylate (HMssEt) and a thermoresponsive di(ethylene glycol)‐containing methacrylate (MEO2MA) units were synthesized. The ratio of HMssEt/MEO2MA units in the random P(MEO2MA‐co‐HMssEt) copolymer block enables the characteristics of well‐defined ssBCs to be amphiphilic or thermoresponsive and double hydrophilic. Their amphiphilicity or temperature‐induced self‐assembly results in nanoaggregates with hydrophobic cores having different densities of pendant disulfide linkages. The effect of disulfide crosslinking density on morphological variation of disulfide‐crosslinked nanogels is investigated. In response to reductive reactions, the partial cleavage of pendant disulfide linkages in the hydrophobic cores converts the physically associated aggregates to disulfide‐crosslinked nanogels. The occurrence of in‐situ disulfide crosslinks provides colloidal stability upon dilution. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2057–2067 相似文献
995.
SoHyun Park Dong Sup Kwag Ung Yeol Lee Dong Jin Lee Kyung Taek Oh Yu Seok Youn Eun Seong Lee 《先进技术聚合物》2014,25(1):16-20
In this study, porous poly(lactide‐co‐glycolide) (PLGA) microparticles with low mass density and large particle size were developed for chronic obstructive pulmonary disease treatment using anticholinergic drug (tiotropium). The porous PLGA microparticles were prepared by the water‐in‐oil‐in‐water (W1/O/W2) multi‐emulsion method using PLGA polymer and ammonium bicarbonate (as a porogen). Herein, soluble starch was incorporated in porous PLGA microparticles for long‐term tiotropium release. In vitro drug release studies determined that the rapid release of tiotropium from porous PLGA microparticles was reduced because of the high viscosity of the incorporated starch. Tiotropium release from porous PLGA microparticles continued up to 3 days. Furthermore, the inhaled microparticles showed longer drug residence in in vivo lung epithelium. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
996.
Daiki Shimizu Juwon Oh Prof. Dr. Ko Furukawa Prof. Dr. Dongho Kim Prof. Dr. Atsuhiro Osuka 《Angewandte Chemie (International ed. in English)》2015,54(22):6613-6617
Treatment of meso‐chlorosubporphyrin with potassium hydroxide in DMSO followed by aqueous work up and recrystallization gave a cyclic trimer consisting of meso‐hydroxysubporphyrin units linked between the central boron atoms and meso‐hydroxy groups. Solutions of this trimer are nonfluorescent, but become fluorescent when exposed to acid or base, since hydrolytic cleavage of the axial B? O bonds generates the meso‐hydroxysubporphyrin monomer or its oxyanion. Ring cleavage of the trimer was also effected by reaction with phenylmagnesium bromide to produce meso‐hydroxy‐B‐phenyl subporphyrin, which can be quantitatively oxidized with PbO2 to furnish a subporphyrin meso‐oxy radical as a remarkably stable species as a result of spin delocalization over almost the entire molecule. 相似文献
997.
998.
999.
Cho DW Lee HY Oh SW Choi JH Park HJ Mariano PS Yoon UC 《The Journal of organic chemistry》2008,73(12):4539-4547
Photochemical reactions taking place between 1,2-diketones and silyl ketene acetals and their excited state reaction mechanisms have been explored. Irradiation of benzene, acetone, or acetonitrile solutions containing 1,2-diketones and silyl ketene acetals is observed to promote formation of 1,4-dioxenes, resulting from [4 + 2]-cycloaddition, oxetanes, arising by Paterno-Buchi processes, and beta-hydroxy-gamma-ketoesters, generated by SET-promoted Claisen-type condensation. These competitive pathways leading from the excited states of the 1,2-diketones to these products are influenced by solvent polarity and the nature of the silyl ketene acetal and 1,2-diketone. The Claisen-type condensation process, following an SET desilylation pathway and predominating when the photoreactions are carried out in the polar solvent acetonitrile, represents an efficient method to prepare a variety of diversely substituted beta-hydoxy-gamma-ketoesters. 相似文献
1000.
Velmurugan Palanivel Shim Jaehong Kim HaeWon Lim Jeong-Muk Kim Seol Ah Seo Young-Seok Kim Jin-Won Kim Kangmin Oh Byung-Taek 《Research on Chemical Intermediates》2020,46(2):999-1015
Research on Chemical Intermediates - We present a novel and in-situ strategy to synthesize silver nanoparticles (AgNPs) onto cotton, leather, and silk fabrics by three different methods: a green... 相似文献