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51.
Shino Manabe Dr. Kazuyuki Ishii Dr. Daisuke Hashizume Dr. Hiroyuki Koshino Dr. Yukishige Ito Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(28):6894-6901
2,3‐trans‐carbamate‐ and ‐carbonate‐carrying pyranosides were very easily anomerised from the β to the α direction in the presence of a Lewis acid compared to other pyranosides. This reaction is caused by endocyclic cleavage of the pyranosides. Evidence for endocyclic cleavage of conformationally restricted pyranosides in the chair form was obtained by intra‐ and intermolecular Friedel–Crafts reactions, chloride addition, and reduction of the generated cation. On the other hand, pyranosides with the distorted conformation were never cleaved in an endocyclic manner. 相似文献
52.
Shunichi Manabe Kazumasa Wakamatsu Yoshimasa Hirata Kiyoyuki Yamada 《Tetrahedron》1979,35(16):1925-1929
13C NMR spectra are reported for derivatives of toxic sesquiterpenes, anisatin (I) and neoanisatin (II). Chemical shifts for each compound have been assigned on the basis of off-resonance decoupling experiments, known chemical shift rules, and comparison of the spectra among the compounds examined. Toxic anisatin (I) is known to isomerize under mild conditions to a non-toxic compound, anisatinic acid. The structure of anisatinic acid has been determined unambiguously to be IIIa by the 13C NMR spectral analysis of a derivative 8 of anisatinic acid. Some aspects of the substituent effects on the 13C chemical shifts obtained in the present investigation are described. 相似文献
53.
S. Shinkai M. Ishihara K. Ueda O. Manabe 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(1-2):111-118
New photoresponsive crown ethers (1H+) having a crown ring and an ammoniumalkyl (H3N+(CH2)n
–, n=4,6,10) group attached to the two sides of an azobenzene have been synthesized. Photoresponsive properties (thermal isomerization, metal extraction, membrane transport, etc.) were examined, and the results were compared with those of other photoresponsive crown ethers and complexons. 相似文献
54.
Le Hoang Lam Tomoko Shimamura Sachiyo Manabe Munetaka Ishiyama Hiroyuki Ukeda 《Analytical sciences》2008,24(8):1057-1060
A newly synthesized substrate, 3-hydroxybutyrylglycyl-glycyl-glycine (3HB-GGG), was applied to the assay of ACE-inhibiting activity to overcome the smaller selectivity and sensitivity of the conventional method. In this study, an ACE-inhibiting assay was improved by the use of a water-soluble tetrazolium salt, 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt (WST-1), for the detection of 3-hydroxybutyrate, derived from 3HB-GGG. The optimized conditions were as follows: 0.333 mM NAD(+), 0.333 mM WST-1, 0.1 mM EDTA, 0.633 U ml(-1) diaphorase, and 0.700 U ml(-1) 3-hydroxybutyrate dehydrogenase. The developed assay was efficiently applicable to evaluate the ACE-inhibiting activity of practical ACE inhibitors. 相似文献
55.
Wenlei Shan Yoshihisa Irimajiri Shengcai Shi Takeshi Manabe 《International Journal of Infrared and Millimeter Waves》2004,25(2):383-391
A fitting method is presented here for the accurate characterization of the IF noise contribution of a sub-millimeter SIS receiver. By fitting the mixer's IF output power response and junction's IV curve of an SIS mixer without LO pumping, we can obtain the IF noise contribution, the physical temperature of the isolator connected just behind the SIS mixer, the output mismatching of the mixer, and the total gain of the IF chain. Differing from a conventional method, which only uses the normal-state (linear) branch of the junction's IV curve, the method proposed here also includes the nonlinear portion around the gap voltage. The dynamic resistance in this portion is varied dramatically, providing us a good probe to characterize the output mismatching of the mixer, as well as other parameters. 相似文献
56.
Self-diffusion coefficients of oxygen in both polycrystalline and single crystal 2MgO·TiO2 have been measured at an ambient oxygen pressure of about 40 mm Hg over the temperature range 1080–1450°C. A convenient method to estimate the volume diffusion coefficient, D1, of this polycrystal in which the relative magnitude in Dg (grain boundary diffusion coefficient) with respect to D1 falls between two extremes, i.e., Dg = D1 and Dg D1, is newly proposed, and its plausibility is examined by comparing the resultant D1 with that of single crystal 2MgO·TiO2. Not only the magnitude but also the temperature dependence of the “apparent” diffusivity of these polycrystalline particles considerably varied with their particle size. The reason for this semiquantitatively interpreted in terms of the relative magnitude of Dg with respect to D1. 相似文献
57.
58.
Yamashita M Yokoyama K Furukawa S Manabe T Ono T Nakata K Kachi-Terajima C Iwahori F Ishii T Miyasaka H Sugiura K Matsuzaki H Kishida H Okamoto H Tanaka H Hasegawa Y Marumoto K Ito H Kuroda S 《Inorganic chemistry》2002,41(8):1998-2000
We have succeeded in synthesizing the Ni(III) complexes doped by Co(III) ions, [Ni(1-x)Co(x)(chxn)(2)Br]Br(2) (x = 0, 0.043, 0.093, and 0.118) by using an electrochemical oxidation method. The single-crystal reflectance spectrum of x = 0.118 shows an intense CT band about 0.5 eV, which is lower than that of [Ni(chxn)(2)Br]Br(2) (1.3 eV). The single-crystal electrical conductivities at room temperature of these compounds increase with increase of the amounts of doping of Co(III) ions. In the ESR spectra, peak-to-peak line widths DeltaH(pp) at room temperature change about 600 G in [Ni(chxn)(2)Br]Br(2) to 200 G in x = 0.118. Such a large x dependence of DeltaH(pp) seems to be ascribed to the increasing contribution from the increasing Curie spins which have smaller line width. Therefore, we have tuned the electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes with strong electron correlations by doping of Co(III) ions. 相似文献
59.
K. Bannai T. Tanaka N. Okamura A. Hazato S. Sugiura K. Manabe K. Tomimori S. Kurozumi 《Tetrahedron letters》1986,27(52):6353-6356
Two efficient syntheses of isocarbacyclin (1) have been realized using highly regioselective direct alkylation of both
- and
-allylic alcohols (2 and 3) 相似文献
60.