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11.
12.
J. Nishimura Y. Ishida M. Mimura N. Nakazawa S. Yamashita 《Journal of polymer science. Part A, Polymer chemistry》1980,18(7):2061-2070
Polymerization of 1,3-bis(p-vinylphenyl) propane (St-C3-St) was investigated by using radical and anionic initiators. Radical polymerization yielded linear polymer with pendant styryl groups in pertinent conditions without gelation. Anionic polymerization with n-butyllithium and sodium naphthalene produced insoluble polymers that, according to infrared (IR) spectroscopy, had no cyclized units. On the other hand, phenylmagnesium bromide gave soluble polymer in HMPA-benzene mixed solvent. Zero-valent nickel catalyst also gave soluble polymer. The soluble polymers could be analyzed by several spectroscopies, and it was confirmed that those obtained by anionic and coordination polymerization had no [3.3]paracyclophane units in the main chain. From these results it was concluded that cationic propagation could be assumed if the polymer Of St-C3-St contained [3.3]paracyclophane units in the main chain. 相似文献
13.
The retention behavior of lymphocyte subpopulations, B cell, T cell and null cell, derived from rat spleen to polyamine-graft-poly(2-hydroxyethyl methacrylate) copolymer (HA) surface was investigated, focusing on the conformational transition of the polyamine side chain as well as the protonation of amino groups in the polyamine grafts. Furthermore, the availability of HA was discussed as a column adsorbent for separation of lymphocyte subpopulations derived from spleen. The conformational transition of polyamine grafts significantly influenced the mode of retention of lymphocyte subpopulations. When polyamine grafts existed in an aggregated conformation (protonatin degree α < 0.5), the retention of lymphocyte subpopulations was decreased in the order B cell> null cell> T cell. On the other hand, when polyamine existed in an extended conformation into the aqueous interior from the matrix interface (α > 0.5), T cell retention became greater than null cell retention, resulting in a decreased B cell> T cell> null cell order. These results indicate that the differential retention of spleen lymphocyte subpopulations is attributed to their differential responses to the change in matrix interface accompanied by the protonation of amino groups. Furthermore, spleen lymphocytes were compared with lymph node lymphocytes in terms of resolution efficacy by an HA copolymer column. 相似文献
14.
Solid sampling technique for direct detection of condensed tannins in bark by matrix-assisted laser desorption/ionization mass spectrometry 总被引:2,自引:0,他引:2
Ishida Y Kitagawa K Goto K Ohtani H 《Rapid communications in mass spectrometry : RCM》2005,19(5):706-710
A novel method for the direct analysis of condensed tannin components in bark was developed on the basis of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) combined with a simple solid sampling technique. The MALDI mass spectra obtained from the wood (bark) powder sample clearly showed a series of peaks corresponding to the sodium ion adducts of condensed tannin oligomers up to around m/z 3000. The results indicate that the condensed tannins in the bark sample used in this work mostly consist of combinations of flavan-3-ol units such as profisetinidin (PF), prorobinetinidin (PR) and prodelphinidin (PD), at least up to 10-mers (m/z approximately 3000). 相似文献
15.
A sensitive method for the determination of nicotinic acid in serum is described which employs high-performance liquid chromatography with fluorescence detection. Nicotinic acid and 2-chloronicotinic acid as an internal standard in deproteinized serum are reacted with N,N'-dicyclohexyl-O-(7-methoxycoumarin-4-yl)methylisourea in acetone to give the corresponding fluorescent 4-hydroxymethyl-7-methoxycoumarin esters. The compounds are separated by reversed-phase chromatography on LiChrosorb RP-18 with isocratic elution using aqueous acetonitrile containing a small amount of sodium 1-hexanesulphonate as a mobile phase. The detection limit of nicotinic acid in serum was 0.2 nmol/ml. The method requires only 100 microliters of serum. 相似文献
16.
Masatoshi Sakae Masanori Katsurada Mayumi Watanabe Fumio Yoneda Sadao Nishigaki Toshimasa Ishida 《Journal of heterocyclic chemistry》1997,34(1):157-160
The reaction of 2-bromoethylamine 1 with methylisothiocyanate 2 under mild condition gave 2-methyl-amino-2-thiazoline 3 as the major product together with two kinds of byproducts, 3-(N-methylthiocar-bamoyl)-2-methyliminothiazolidine 4 and N,N′-dimethyl-N-(2-thiazolin-2-yl)thiourea 5. Thermal isomer-ization of 5 to 4 was observed. The structures of the byproducts were confirmed by X-ray crystallography. 相似文献
17.
Structure-activity relationships of a new antifungal imidazole, AFK-108, and related compounds 总被引:1,自引:0,他引:1
Hori K Sakaguchi A Kudoh M Ishida K Aoyama Y Yoshida Y 《Chemical & pharmaceutical bulletin》2000,48(1):60-64
Fungicidal activity of widely used imidazole antifungal drugs in topical applications is not so strong in spite of their fungistatic activities against dermatophytes and pathogenic yeasts. In order to improve fungicidal activity of imidazole antifungal agents, a series of novel imidazole derivatives having a hydrophobic substituent derived from isoprenoid were synthesized. The efficacy of these compounds was evaluated with respect to direct cell-membrane damaging activity, ergosterol biosynthesis inhibition, minimum growth-inhibitory concentration (MIC) and therapeutic effect for experimental dermatophytosis of guinea pigs. Among the newly synthesized compounds, the geranyl derivative named AFK-108 (2a) showed the highest in vivo fungicidal activity with both cell membrane damaging activity and ergosterol biosynthesis inhibition in vitro. 相似文献
18.
T. Kobayashi I. Endo A. Fukumi T. Horiguchi Y. Ishida T. Kondo T. Kuwamoto N. Minamoto T. Nakamura T. Takahasi 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1997,39(3):209-216
Atomic-beam laser spectroscopy with fluorescence detection is applied to investigate the hyperfine structure (hfs), Stark and Zeeman effects of the electric dipole transitions of Sm i. The measurements are performed for the four transitions of 0 → 15650.55, 292.58 → 15650.55, 292.58 → 15567.32, and 1489.55 → 16890.59 cm-1. The hfs constants of the upper and lower levels and the isotope shifts of the transitions are determined. The tensor polarizability of the 15650.55 cm-1 level is found to be α2 = -556.2 ± 11.8 kHz/(kV/cm)2. Thanks to the accurate g values of the lower levels [Childs, W.J., Goodman, L.S.: Phys. Rev. A 6, 2011 (1972)], the g values of the upper levels are obtained from the observed Zeeman splittings. The values are found to be -0.115907(79), 2.22259(20) and 1.599968(51) for the 15650.55 cm-1 .1, 15567.32 cm-1 and 16890.59.cm-1 levels, respectively. 相似文献
19.
Apirat Laobuthee Hatsuo Ishida Suwabun Chirachanchai 《Journal of inclusion phenomena and macrocyclic chemistry》2003,46(3-4):179-185
This study was carried out with the aim to optimize the dissolution propertiesof diclofenac (DIC) – a non-steroidal anti-inflammatory drug sparingly solublein water – through association -with -cyclodextrin (CD). Theeffect of CD on the aqueous solubility of DIC was evaluated by thephase solubility method. The amount of DIC dissolved increased linearly withthe addition of CD according to an AL type plot and without precipitationof the complex. The apparent stability constant of the complex, calculated supposinga 1:1 stoichiometry, was 295 M-1; this value was confirmed by circulardichroism analysis. DIC/CD interactions were also studied in water by1H and 13C NMR spectroscopy. Equimolar DIC/CD solid systems were prepared by physical-mixing, kneading, co-evaporation andfreeze-drying, and their properties in the solid state studied by DifferentialScanning Calorimetry, X-ray powder diffractometry and Fourier-TransformInfrared analysis. For sake of comparison, the mixture of DIC and CDseparately lyophilized was investigated too. The results demonstrated that thefreeze-dried product had the highest degree of amorphization and they were inagreement with the existence of an inclusion complex in the solid state. Thedissolution profiles of the drug from each solid system were affected by its physico-chemical properties, the freeze-dried being the most rapidly dissolvingforms. 相似文献
20.
A. Fukumi I. Endo T. Horiguchi Y. Ishida T. Kondo T. Kuwamoto H. Matsuzaki T. Nakamura T. Takahashi 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1997,42(4):243-249
Systematic study of hyperfine structures, Zeeman and Stark effects in Sm I is performed for the lowest 7G1-6 levels belonging to the configuration 4f 66s6p by atomic-beam laser spectroscopy with fluorescence detection. The hyperfine coupling constants of 7G2-6 levels are determined. From the Zeeman splittings for the 4f 66s 2 7F2-6 ? 4f 66s6p 7G2-6 transitions, g-values are determined for the 7G2.6 levels and the precision is improved by several orders of magnitude. From the Stark splittings for the 7F0-3 ? 7G1-3 transitions, tensor polarizabilities α 2(J) are determined for the upper 7G1-3 levels. Particularly for the 7G1 level (15 650.55 cm?1) which has close-lying opposite-parity level, the isotope dependence of α 2(J) is clearly observed for the first time. 相似文献