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81.
Tsukasa Ikeda Ryoichi Kojin Chul-joong Yoon Hiroshi Ikeda Masao Iijima Kenjiro Hattori Fujio Toda 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(3-4):669-674
Cyclodextrin (CD) has a hydrophobic cavity which acts like a binding site of an actual enzyme. But enzymatic turnover reaction did not occur in CD-catalyzed reactions. -CD was modified by a histamine group to attach a reactive functional group. -CD-histamine accelerates the hydrolysis of p-nitrophenyl acetate. Catalytic rate constant of this reaction is close to an actual enzyme, -chymotrypsin. Enzymatic turnover reaction is realized with this compound at around neutral pH value. 相似文献
82.
The cw dye laser excitation spectrum of the vibronic band of HCCl was observed between 16 539 and 16 656 cm?1 with the Doppler-limited resolution, 0.03 cm?1. The HCCl molecule was generated by the reaction of discharged CF4 with CH3Cl. The observed spectra were assigned to c-type transitions with ΔKa = ±1 and also to axis-switching transitions with ΔKa = 0 or ?2, but all with K′a = 0, both for HC35Cl and HC37Cl. A rotational analysis yielded the rotational constants and quartic centrifugal distortion constants for the ground vibronic state and the band origin. A weak vibronic band, about one-third as intense as the main band, was found at about 57 cm?1 to the violet of the main band for both isotopic species, and was ascribed to a transition from the ground vibronic state to a vibrational level, possibly (041), of the à state. The rotational levels of HC35Cl in the à state showed a large perturbation; the J′ = 8, 9, and 10 levels were found to be split into two components. A normal coordinate analysis was carried out to calculate the centrifugal distortion constants and the inertia defect, which were in fair agreement with the observed values. The molecular structure of HCCl in the ground vibronic state was recalculated from the rotational constants of the two isotopic species combined with the 0.75B0 + 0.25C0 value previously reported for DC35Cl. 相似文献
83.
The title compounds and were synthesized by the usual dithia[3.3]phane coupling and photodesulfurization route. Investigation of their physical properties established their molecular dimension and conformation. Transannular interaction disclosed by their electronic spectra was explained by MO calculations. 相似文献
84.
Yoshihiro Takahashi Takashi Kitamura Kenji Uchida Masao Tomura 《Journal of luminescence》1980,21(3):269-275
Emission spectra and decay times of the fluorescence excited at the absorption edge region in pyrene crystals were measured. At liquid nitrogen temperature, the fluorescence under the excitation at 390 nm is considered as the excimer emission and its band peak shifts a little to the short wavelength in comparison with that of the excimer emission under the excitation at 360 nm. The emission decay times under the excitation at the 390 nm and 360 nm are about 155 ns and 180 ns, respectively, at liquid nitrogen temperature. The former decay time changes its value abruptly near 127 K. This abrupt change of the decay time may be due to the phase transition in pyrene crystals. 相似文献
85.
86.
Green oxidation with aqueous hydrogen peroxide 总被引:2,自引:0,他引:2
Aqueous H2O2 is an ideal oxidant, when coupled with a tungstate complex and a quaternary ammonium hydrogensulfate as an acidic phase-transfer catalyst. It oxidizes alcohols, olefins, and sulfides under organic solvent- and halide-free conditions in an economically, technically, and environmentally satisfying manner. 相似文献
87.
Machida K Takehara E Kobayashi H Kikuchi M 《Chemical & pharmaceutical bulletin》2003,51(12):1417-1419
Two new iridoid glycosides, 7 beta,8 beta-epoxy-8 alpha-dihydrogeniposide (1) and 8-epiapodantheroside (2), were isolated, together with six known (3-8) and three artifact (9-11) iridoids, from the leaves of Gardenia jasminoides cv. fortuneana Hara. Their structures were established based on chemical and spectral data. 相似文献
88.
Russulanorol (1), a new norsesquiterpenoid with a novel carbon skeleton, was isolated from the fruiting bodies of Russula delica FR. (Russulaceae) together with three known sesquiterpenoids. The structure of 1 was elucidated on the basis of spectral data and chemical transformation. Compound 1 is an equilibrium mixture of two stereoisomers (1a, b) on the C-11 acetal carbon. 相似文献
89.
Density functional calculations have been used to investigate the (0 0 1) surface of cubic SrZrO3 with both SrO and ZrO2 termination. Surface structure and electronic structure have been obtained. The SrO surface is found to be similar to its counterpart in SrTiO3, while there are marked differences between the ZrO2 and TiO2 terminations in SrZrO3 and SrTiO3, respectively, concerning surface relaxation and rumpling. For the ZrO2-terminated surface of SrZrO3, the covalency of the interaction between the outmost Zr and the O beneath is enhanced as a result of their bond contraction. The band gap reduction and the presence of the surface states are also discussed in relation with the behavior of the electrostatic potential. 相似文献
90.
Hidemasa Hidaka Masao Hirayama Kazuhiko Yamada 《Journal of carbohydrate chemistry》2013,32(4):509-522
I. INTRODUCTION Recently the study of oligosaccharides has been extensively pursued in Japan after the findings of the remarkable biofunctions and usefulness of fructooligosac-charides for human health, improving the intestinal microflora and importance in livestock nutrition. 相似文献