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31.
A validated LC‐MS/MS method for the determination of canagliflozin,a sodium–glucose co‐transporter 2 (SGLT‐2) inhibitor,in a lower volume of rat plasma: application to pharmacokinetic studies in rats
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Shinji Kobuchi Kyoka Yano Yukako Ito Toshiyuki Sakaeda 《Biomedical chromatography : BMC》2016,30(10):1549-1555
Canagliflozin is a novel, orally selective inhibitor of sodium‐dependent glucose co‐transporter‐2 (SGLT2) for the treatment of patients with type 2 diabetes mellitus. In this study, a validated liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for the quantitative analysis of canagliflozin in a lower volume of rat plasma (0.1 mL) was established and applied to a pharmacokinetic study in rats. Following liquid–liquid extraction by tert‐butyl methyl ether, chromatographic separation of canagliflozin was performed on a Quicksorb ODS (2.1 mm i.d. × 150 mm, 5 µm size) using acetonitrile–0.1% formic acid (90:10, v/v) as the mobile phase at a flow rate of 0.2 mL/min. The detection was carried out using an API 3200 triple‐quadrupole mass spectrometer operating in the positive electrospray ionization mode. Selected ion monitoring transitions of m/z = 462.0 [M + NH4]+ → 191.0 for canagliflozin and m/z = 451.2 [M + H]+ → 71.0 for empagliflozin (internal standard) were obtained. The validation of the method was investigated, and it was found to be of sufficient specificity, accuracy and precision. Canagliflozin in rat plasma was stable under the analytical conditions used. This validated method was successfully applied to assess the pharmacokinetics of canagliflozin in rats using 0.1 mL rat plasma. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Stochastic equations indexed by negative integers and taking values in compact groups are studied. Extremal solutions of the equations are characterized in terms of infinite products of independent random variables. This result is applied to characterize several properties of the set of all solutions in terms of the law of the driving noise. 相似文献
34.
Unmodified and SiCl4-modified spherical zirconia-supported methylaluminoxane were used as cocatalyst for propylene polymerization as well as ethylene/1-hexene copolymerization in combined with Me2Si(η3-C13H8)(η1-NtBu)TiMe2 (1) at 0 °C. The modification with SiCl4 improved the catalytic activity. The improvement was clearer in ethylene/1-hexene copolymerization than in propylene polymerization. The number average molecular weight (Mn) of polypropylenes increased linearly against the polymerization time regardless the cocatalyst used to give polymers with narrow molecular weight distribution (Mw/Mn < 1.32), indicating the living nature of the catalytic systems. Thus, propagation rate constant (kp) and the number of active centers (C*) were evaluated from Mn and the number of polymer-chains. When the zirconia was modified with SiCl4, the kp value decreased and the C* increased. The latter effect was more significant to enhance the catalytic activity. 相似文献
35.
Ayako Yano Nobuyuki Akai Hiroshi Ishii Chikahiro Satoh Takayuki Hironiwa Keith R. Millington Munetaka Nakata 《Polymer Degradation and Stability》2013
Thermal oxidative degradation of additive-free polypropylene pellets heated isothermally in dry air at 150 and 180 °C (below and above the melting point of 163 °C) was investigated by multichannel Fourier-transform chemiluminescence spectroscopy. The initial peak wavelength of chemiluminescence emission at 490 nm remained constant during the early stages of thermal degradation, but new emissions developed with time in the red spectral region over an extended oxidation period. The time-dependent luminescence spectra were deconvoluted into three emission bands by least-squares fitting using Gaussian curves. We concluded that at least three groups of luminescent species (luminophores), having different conjugation lengths, were generated by thermal oxidation over extended periods and show luminescence around 490, 660, and 740 nm. 相似文献
36.
Abstract Hexakis(4-(4′-heptyloxy)biphenoxy)cyclotriphosphazene (HHCP) was synthesized from hexachlorocyclotriphosphazene and 4-heptyloxy-4′-hydroxybiphenyl. The mesogenicity of HHCP was studied by DSC, FTIR spectroscopy and polarizing microscopy. Enantiotropic smectic C and nematic phases were observed between 450 and 455 K and 455 and 456 K, respectively, on heating, and between 456 and 455 K (nematic) and 455 and 440 K (smectic C) on cooling from the isotropic liquid phase. The introduction of the heptyloxybiphenoxy groups as side chains into cyclotriphosphazene has generated the liquid crystalline phase. FTIR spectroscopy showed that the P=N and P-O-(C) stretching vibrations converted to lower frequencies from 1224 to 1210 cm?1 and from 920 to 910cm?1, respectively, at the crystalline (C)-Sc phase transition. This result suggests that the state of the cyclotriphosphazene ring dramatically changes near the C-Sc phase transition. 相似文献
37.
Katsuhito Suzuki Hiroaki Okumura Kazuo Kitagawa Shinji Sato Antonio Norio Nakagaito Hiroyuki Yano 《Cellulose (London, England)》2013,20(1):201-210
Microfibrillated cellulose (MFC), a mechanically fibrillated pulp mostly consisting of nanofibrils, is a very attractive material because of its high elastic modulus and strength. Although much research has been done on composites of MFC and polypropylene (PP), it has been difficult to produce such composites at an industrial level because of the difficulties in using MFC in such composites are not only connected to the polarity (that can be improved with compatibilizers), but also with the challenge to make a homogeneous blend of the components, and also the low temperature stability of cellulose that could cause problems during processing. We developed a new processing method which enables continuous microfibrillation of pulp and its melt compounding with PP. Never-dried kraft pulp and powdered PP were used as raw materials to obtain MFC by kneading via a twin-screw extruder. Scanning electron microscopy showed nano to submicron wide fibers entangled in the powdered PP. MFC did not aggregate during the melt compounding process, during which the water content was evaporated. Maleic anhydride polypropylene (MAPP) was used as a compatibilizer to reinforce interfacial adhesion between the polar hydroxyl groups of MFC and non-polar PP. We investigated the effect of MAPP content on the mechanical properties of the composite, which were drastically improved by MAPP addition. Needle-leaf unbleached kraft pulp (NUKP)-derived MFC composites had better mechanical properties than needle-leaf bleached kraft pulp (NBKP)-derived MFC composites. Injection molded NUKP-derived MFC composites had good mechanical and thermal properties. The tensile modulus of 50 wt% MFC composite was two times, and the tensile strength 1.5 times higher than that of neat PP. The heat distortion temperature of 50 wt% MFC content composite under 1.82 MPa flexural load was increased by 53 °C, from 69 to 122 °C. This newly developed continuous process using powder resin has the potential for application at an industrial level. 相似文献
38.
Kuniaki Marui Yuuki Higashiura Shintaro Kodama Suguru Hashidate Akihiro Nomoto Shigenobu Yano Michio Ueshima Akiya Ogawa 《Tetrahedron》2014
The oxidation of alcohols using catalytic amounts of metal complexes is highly attractive from the viewpoint of green chemistry principles. However, examples of metal complex-catalyzed oxidations of alcohols with O2 using water as the solvent are still rare, and precious metals, high-pressure O2 or air, and a stoichiometric amount of base are often required. In this study, it was found that an oxovanadium-4,4′-t-Bubpy (4,4′-di-tert-butyl-2,2′-bipyridyl) complex exhibited high catalytic activity in the oxidation of benzhydrols under an atmosphere of O2 in water as the sole solvent. Interestingly, this catalytic oxidation method could be applied to the gram-scale aerobic oxidation of alcohols in water under the atmosphere. 相似文献
39.
Yutaka Aoyagi Kei Ozawa Tatsuya Kobayashi Tomoyo Hasuda Ming-Yu Gui Yong-Ri Jin Xu-Wen Li Haruhiko Fukaya Reiko Yano Yukio Hitotsuyanagi Koichi Takeya 《Tetrahedron》2014
Transformation of plant-origin 7,14-dihydroxy-ent-kaurenes to ent-abietanes having a cis-fused α-methylene γ-lactones was accomplished efficiently under the Mitsunobu reaction conditions. The yields of the desired products were apparently influenced by the steric hindrance at C-1. The cytotoxic activity on P388 murine leukemia cells of the ent-abietanes having cis-fused α-methylene γ-lactones produced were assayed. 相似文献
40.
H. Kuboki H. Okuno A. Hershcovitch T. Dantsuka H. Hasebe K. Ikegami H. Imao O. Kamigaito M. Kase T. Maie T. Nakagawa Y. Yano 《Journal of Radioanalytical and Nuclear Chemistry》2014,299(2):1029-1034
A differential pumping system with a Plasma Window (PW) has been developed for an application to a window-less He gas charge stripper. A PW with Southern Methodist University design was newly fabricated and tested off-line for evaluation of differential pumping efficiency. Switching gases for plasma seed from Ar to He was tested. It was found that the PW reduced the pressure at the first differential pumping section to 1/13 for Ar and to 1/17 for He, comparing with differential pumping without PW. At the second pumping section, the pressures were drastically reduced to 1/160 and to 1/4,520 for Ar and He, respectively. These pressure reduction factors indicate that one differentially pumped stage could be removed from a conventional differential pumping system. 相似文献