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101.
Srinivasan A Ishizuka T Osuka A Furuta H 《Journal of the American Chemical Society》2003,125(4):878-879
Meso-hexakis(pentafluorophenyl)-substituted doubly N-confused hexaphyrins and their metal complexes were synthesized for the first time, and the structures were elucidated by X-ray single-crystal analyses. The free base form of oxidized hexaphyrin (5) had two preorganized N3O pockets in the macrocyclic core, where a hydrogen-bonding network was formed to keep the molecule planar (the mean plane deviation is 0.054 A). The formation of a planar bis-Cu(II) complex was confirmed by UV/vis, magnetic susceptibility measurements, and X-ray crystallography. The bis-Ni(II) complex (7), on the other hand, was distored from planarity, but it changed to the planar structure upon solvent (acetonitrile) coordination as judged by the observation of a sharp Soret-like band in absorption spectra and the X-ray structures of the complexes. 相似文献
102.
L-[5'-2H2]Histidine was used as a substrate to investigate the enzymatic reaction mechanism with histidine ammonia-lyase from Pseudomonas fluorescens. The study was performed to determine the exchange rate of deuterium at C-5' of the imidazole ring with solvent hydrogen relative to the net urocanic acid production. The extent of hydrogen exchange at C-5' of histidine or urocanic acid was measured by gas chromatography-mass spectrometry-selected ion monitoring, monitoring the molecular ion intensities of the respective gas chromatographic derivatives, at m/z 380 and 379 for histidine and at m/z 267 and 266 for urocanic acid. The observed hydrogen exchange at C-5' suggested a reversible mechanism via a carbanion intermediate in the reaction with histidine ammonia-lyase. 相似文献
103.
Shu?KobayashiEmail author Ryo?Akiyama Takayuki?Furuta Mitsuhiro?Moriwaki 《Molecules Online》1998,2(1):35-39
Michael reactions of α,β-unsaturated ketones and aldol-type reactions of acetals with polymer- supported silyl enol ethers (PSSEEs) proceeded smoothly using a rare earth triflate as a catalyst. The Swollen-Resin Magic Angle Spinning (SR-MAS) NMR technique has been successfully used for the development of the reactions. 相似文献
104.
[reaction: see text] N-alkyl-substituted meso-tetrapyrrolylporphyrin (TPyrP) and its derivatives were synthesized for the first time via an acid-catalyzed condensation between N-alkyl-2,4-diformylpyrrole and unsubstituted pyrrole and a subsequent deformylation reaction. X-ray structural analysis of formyl-substituted TPyrP shows the tilting of meso pyrrole rings ca. 60 degrees to the porphyrin plane. Formyl groups of meso pyrrole rings were removed by treatment with trifluoroacetic acid (TFA) in pyrrole. 相似文献
105.
106.
Takeshi Furuta Youko Kusuya Tze-loon Neoh Lars Rehmann Sun-hwa Beak Hidefumi Yoshii 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(1-2):107-111
The potential for surface modification of paper by modified cyclodextrins was demonstrated by the model system of Japanese washi paper and monochlorotriazinyl-β-cyclodextrin (MCT-β-CD). MCT-β-CD was covalently bonded to the paper. The optimal bonded reaction conditions were found to be 10 min at 150 °C with a moisture content of less than 2.5 (g water/g dry paper). The bounded MCT-β-CD on the paper was able to include and release hinokitiol representing the group of antibacterial agents. The maximum molar inclusion ratio of hinokitiol in the immobilized MCT-β-CD was around 0.8. The release rates of hinokitiol, included in the fixed MCT-β-CD, were monitored at 50 °C for different relative humidities. The release rate was strongly influenced by the relative humidity. These results demonstrate that the antibacterial agent can be included and released from MCT-β-CD fixed on the paper. The antibacterial activity of the fixed hinokitiol against airborne microorganisms was demonstrated. 相似文献
107.
108.
Furuta T Sakai M Hayashi H Asakawa T Kataoka F Fujii S Suzuki T Suzuki Y Tanaka K Fishkin N Nakanishi K 《Chemical communications (Cambridge, England)》2005,(36):4575-4577
An artificial phospholipid, possessing saturated alkyl chains as a membrane anchor and protein recognition site as well as an Fe(III)-EDTA moiety as a protein cleavable polar head group, was designed and synthesized based on the amidite method for the purpose of examination of cleavage of integral membrane proteins. 相似文献
109.
A capillary gas chromatographic-mass spectrometric method for the simultaneous determination of androstenedione and testosterone in human plasma using [19,19,19-2H3]androstenedione and [19,19,19-2H3]testosterone as internal standards is described. For calculation of plasma androstenedione and testosterone, peak heights were measured by selected-ion monitoring of the molecular ions of the heptafluorobutyryl derivatives of androstenedione and [2H3]androstenedione (m/z 482 and 485) and of testosterone and [2H3]testosterone (m/z 680 and 683). The isotope dilution method needed no complex corrections for contributions and provides a sensitive and reliable technique with good accuracy, precision and reproducibility. 相似文献
110.
H Ueki K Furuta T Funakoshi Y Matsunami Y Kubota 《Chemical & pharmaceutical bulletin》1982,30(3):1054-1058