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991.
4-(2'-Hydroxyethyl)azetidin-2-one, an important synthetic intermediate for carbapenem, and its substituted derivatives have been synthesized from 4-acetoxy-2-pyridones by photolysis, catalytic hydrogenation, followed by basic hydrolysis in the presence of sodium borohydride. 相似文献
992.
Mitsuyoshi Matsuo Shigenobu Matsumoto Toshihiko Ozawa 《Magnetic resonance in chemistry : MRC》1983,21(4):261-264
Highly resolved electron spin resonance spectra of the α-tocopheroxyl or 2,2,5,7,8-pentamethylchroman-6-oxyl radicals were obtained from the oxidation of α-tocopherol (vitamin E) or its model compound, 2,2,5,7,8-pentamethylchroman-6-ol, with 2,2-diphenyl-1-picrylhydrazyl or superoxide ion. Complete assignments of the hyperfine coupling constants of these radicals were made on the basis of the spectra of the deuterated isotopomers of the 2,2,5,7,8-pentamethylchroman-6-oxyl radical. The large coupling constant due to the methyl group at C-5 in the α-tocopheroxyl radical may have implications for the high reactivity toward radicals of C-5 in α-tocopherol. 相似文献
993.
Taishiro Nakagawa Takashi Ishihara Hideaki Yoshida Takashi Yoneya Kaori Wakamatsu Toshihiko Kadoya 《Journal of separation science》2010,33(14):2045-2051
Accurate prediction of the elution tendency of monoclonal antibodies in column chromatography would be beneficial for the efficient setup of purification procedures. Hydroxyapatite chromatography experiments using 37 recombinant human monoclonal antibodies were performed by sodium chloride gradient elution with 5 mM sodium phosphate to correlate the retention times with antibody structures (subclass and light‐chain isotypes). The contribution of metal affinity interactions in the interaction of antibodies with hydroxyapatite was investigated by (i) eliminating 5 mM sodium phosphate in buffers, (ii) comparing sodium chloride versus sodium phosphate gradient elutions, and (iii) using IgG4 antibodies with a leucine→glutamate mutation. By using antibodies of different subclasses but with identical Fab regions, the elution behavior in sodium chloride elution could be classified by subclass and type of light chain. It is considered that the retention of monoclonal antibodies to hydroxyapatite is affected by the cooperation of phosphoryl cation exchange and metal affinity interactions. The contribution of the metal affinity interactions is greater in the sodium chloride gradient elution method than in the sodium phosphate gradient elution method. 相似文献
994.
995.
Hanamoto T Koga Y Kido E Kawanami T Furuno H Inanaga J 《Chemical communications (Cambridge, England)》2005,(15):2041-2043
The palladium catalyzed cross-coupling reactions of aryl iodides and 5-tributylstannyl-4-fluoropyrazole prepared from fluoro(tributylstannyl)acetylene proceeded smoothly giving the corresponding 5-aryl-4-fluoropyrazole in good yields. 相似文献
996.
A novel fluorescent probe, the detection mechanism of which is based on the 'on-off' switching of a FRET triggered by the *OH-induced cleavage of a DNA strand, has been developed for the ratiometric imaging of *OH. 相似文献
997.
Moriguchi I Koga Y Matsukura R Teraoka Y Kodama M 《Chemical communications (Cambridge, England)》2002,(17):1844-1845
Mesoporous carbonaceous materials with relatively high surface area have been synthesized by a new method composed of in situ polymerization of divinylbenzene in the hydrophobic phase of a hexagonally arrayed micelle/silicate nanocomposite and subsequent carbonization and hydrofluoric acid treatments, while rod-like carbons were obtained from a direct incorporation of divinylbenzene into the mesopores of MCM-41. 相似文献
998.
The annulation method based on 2H-cyclohepta[b]furan-2-ones was applied for the synthesis of 2-alkylazulenes; 2-R-azulene (R = Et, i-Pr, n-Pr, i-Bu). Tropolone p-toluenesulfonate was used as a starting compound. By the two step synthesis, 1-carboxylic-3-cyanoazulene derivatives were obtained. Treatment of 1-carboxylic-3-cyanoazulene derivatives with aq H2SO4 resulted in decarboxylation and elimination of cyano group to give 2-alkylazulenes in good yields. 相似文献
999.
Eugene S. Kryachko Eduardo V. Ludeña Toshikatsu Koga 《Journal of mathematical chemistry》1992,11(1):325-339
The local-scaling transformation version of density functional theory is extended to the treatment of excited states. This is accomplished in the context of the super-particle formulation of Katriel [Int. J. Quant. Chem. 23(19$3)1767]. It is shown that for a given superparticle generating wave function, the energy density functional corresponding to the excited-state super-system may be explicitly constructed. The derivation of an Euler-Lagrange equation for the composite excited-state density is discussed. A preliminary calculation for the 21S state of helium is reported. 相似文献
1000.
Toshihiko Hanai Hiroyuki Hatano Noriyuki Nimura Toshio Kinoshita 《Journal of separation science》1991,14(7):481-483
The electroosmotic migration times of fructose, water, and phenol have been measured in several solutions. The electroosmotic flow rate was fundamentally dependent on buffer concentration and on the concentration of additives such as sodium chloride; additives such as methanol and sodium dodecylsulfate did not influence the flow rate, yet tetrabutylammonium bromide had a significant effect. 相似文献