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151.
152.
Noda K Narayama Y Goto Y Kobayashi M Kuronuma H Iwai S Itoh K Katoh N Tadano K 《Journal of chromatographic science》2011,49(7):519-523
A modified method for the quantitative determination of bepridil hydrochloride in human plasma is described. This method is unrelated to chemical methods currently in use. The mobile phase is 50 mM phosphate buffer (pH3.0)-methanol-acetonitrile-triethylamine (57:3:40:1, v/v), and the samples are fractionated on a C8-3 column (150 × 4.6 mm, 5 μm) using a flow rate of 0.9 mL/min. Bepridil was detected by UV spectroscopy at 254 nm. The retention times of bepridil and 1-naphthol were 12.6 min and 7.5 min, respectively; there was no interference originating from human plasma. We confirmed that the bepridil and 1-naphthol peaks were not influenced by the presence of 32 commercial medicines frequently co-administered with bepridil. Additionally, the concentration of bepridil in the plasma of five patients treated with bepridil for atrial fibrillation was measured. These samples were collected just before each dosage of bepridil. Their rhythm and rate control were well maintained. Trough concentrations ranged from 233.9 to 347.4 ng/mL, similar to previously reported values. 相似文献
153.
A new direct conversion of O,O-acetals to esters via O,P-acetal intermediates was developed. The regioselective cleavage of unsymmetrical cyclic acetals occurred to give the more crowded esters as single isomers. 相似文献
154.
155.
Okada T Yamanaka K Hirose Y Goto Y Tani T Inagaki S 《Physical chemistry chemical physics : PCCP》2011,13(17):7961-7967
The excited state characteristics of phenylene (Ph)-bridged periodic mesoporous organosilica (PMO) powders with crystal-like and amorphous wall structures are investigated. Crystal-like Ph-PMO has a molecular ordering of the bridging organic moieties with intervals of 0.76 and 0.44 nm parallel and perpendicular to the mesochannel direction, respectively, whereas amorphous Ph-PMO has no molecular-level periodicity in the wall. Fluorescence from the exciton and excimer of the Ph moieties and the defect center in the silicate network were detected at room temperature, but fluorescence from the excimer and the defect center were not detected at 77 K for crystal-like Ph-PMO dispersed in a methanol/ethanol mixed solvent. The decay curve of the exciton fluorescence of crystal-like Ph-PMO at room temperature was analyzed successfully using a one-dimensional diffusion model quenched by the defect center and the excimer site. The results were discussed in comparison with those for the crystal-like biphenylene-bridged PMO reported in the preceding paper (Yamanaka et al., Phys. Chem. Chem. Phys., 2010, 12, 11688-11696). The existence of excited states with various conformations including ground state dimers or aggregates of the Ph moieties was suggested for amorphous Ph-PMO. It was clearly apparent that the differences in the excited state dynamics reflected the differences in the molecular-level structure in the wall. 相似文献
156.
We have succeeded in the total synthesis of siomycin A, a representative compound of the thiostrepton family of peptide antibiotics, featuring the one-pot cyclization-elongation of our strategic intermediates and the late-stage formations of the thiazoline and dehydroamino acid moieties. 相似文献
157.
Hiromasa Kurosaki Rakesh K Sharma Masami Otsuka Masafumi Goto 《Analytical sciences》2003,19(4):647-648
The structure of 7,8-dihydroxy-4-methylcoumarin was determined by an X-ray diffraction method. The compound crystallized in the triclinic space group P1, Z = 2, with a = 7.631(2), b = 9.456(5), c = 7.075(3)A, alpha = 103.13(3), beta = 91.84(3), gamma= 68.21(3) degrees, and V= 460.9(3)A3. The X-ray crystal structure was also compared with those of 5,7-dihydroxy-4-methylcoumarin and 7-hydroxy-4-methylcoumarin. 相似文献
158.
Capillary gas chromatography of hydroxylated bile acid stereoisomers of the allo and normal series 总被引:1,自引:0,他引:1
T Iida T Momose T Tamura T Matsumoto J Goto T Nambara F C Chang 《Journal of chromatography. A》1987,389(1):155-164
Relative retention times and methylene unit (MU) values were determined for 56 bile acids of the allo (5 alpha, A/B-trans) and normal (5 beta, A/B-cis) series, which differ from one another in the number, position and configuration of the hydroxyl groups at positions C-3, C-6, C-7 and/or C-12. The bile acids were derivatized to their methyl ester O-trimethylsilyl ethers (Me-TMS) and methyl ester O-dimethylethylsilyl ethers (Me-DMES), and chromatographed on fused-silica capillary columns, chemically bonded with non-selective OV-1 and selective PEG-20M liquid phases. Of the four possible combinations of derivatives and columns examined, Me-DMES on OV-1 and Me-TMS on PEG-20M were most suitable. The differences in the MU values between the 5 alpha- and 5 beta-series, and between the Me-DMES and Me-TMS ether derivatives, are also summarized. These retention data would be helpful in the identification of closely related bile acid stereoisomers or for estimation of their structures. photolysis. 相似文献
159.
M. Fujita T. Endo A. Yamazaki T. Sonada T. Miyake E. Tanaka T. Shinozuka T. Suzuki A. Goto Y. Miyashita N. Sato Y. Wakabayashi N. Hokoiwa M. Kibe Y. Gono T. Fukuchi A. Odahara 《Hyperfine Interactions》2004,159(1-4):245-249
The g-factor of the 27− isomer state of 152Dy has been measured using the Time-Integral Perturbed Angular Distribution (TIPAD) method. The high-spin states of 152Dy have been populated by 141Pr(16O,p4n)152Dy reaction at E = 115 MeV from the AVF cyclotron at CYRIC. The paramagnetic correction factor of Dy ions in Pr has been determined to be
4.2(5) by the Time-Differential Perturbed Angular Distribution (TDPAD) measurement of the 21− state of 152Dy. As a result, the g-factor of the 27− isomer state of 152Dy has been obtained to be +0.09(5). This shows the smaller value than the expected one of +0.39 deduced from a fully aligned
configuration of π(h
11/2
2) ⊗ ν(f
7/2
2
h
9/2
i
13/2). 相似文献
160.
Conjugated polymers consisting of pyrrole or an N‐substituted pyrrole bridged by methine with a mesogenic group were synthesized. Chemical structures of the products were confirmed with IR, NMR, UV–visible (UV–vis) spectroscopy, and gel permeation chromatography analysis. Liquid crystallinity was examined with differential scanning calorimetry measurements and polarizing optical microscopy observations. Liquid crystal domains of the polymer were macroscopically oriented in one direction by an external magnetic force (10 Tesla). The polymer orientation was confirmed by optical microscopy and X‐ray analysis. One of the polymers exhibited a striated fan‐shaped texture when observed with a polarizing optical microscope. This is attributed to the formation of a chiral smectic C (SmC*) phase, which is a property of ferroelectricity. Spontaneous polarization of the polymer occurred at 110 nC/cm2. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 616–629, 2005 相似文献