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291.
Aiko Nakano Atsuhiro Osuka Iwao Yamazaki Tomoko Yamazaki Yoshinobu Nishimura 《Angewandte Chemie (International ed. in English)》1998,37(21):3023-3027
Up to 14 porphyrin rings are present in the title compounds 1 , which are readily available with high regioselectivity from linear nickel–zinc porphyrins. Upon irradiation with light a rapid energy transfer from the peripheral porphyrin rings to the diporphyrin core takes place. 相似文献
292.
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294.
Toru Shigematsu Nobuya Okada Kazuki Nomura Chihiro Kataoka Saori Hori Iwao Takahashi 《高压研究》2019,39(2):313-323
ABSTRACTUnpasteurized draft sake has a potentially high market value, due to its fresh flavor and fruity taste, compared with conventional thermal-pasteurized sake. However, the shelf life of draft sake is limited. To increase the shelf life of draft sake, it is necessary to suppress flavor and taste deterioration resulting from inactivation of enzymes produced by koji-mold. Draft sake was treated with high hydrostatic pressure (HHP) of 200 to 500?MPa at ?7 to 50°C to analyze the inactivation of α-amylases, glucose-forming enzymes, and acid carboxypeptidases. We found significant inactivation of enzymes produced by koji-mold in draft sake subjected to HHP treatment at both high and low temperature. However, HHP treatment at low temperature effectively inactivated enzymes while retaining the fresh flavor and fruity taste of draft sake. 相似文献
295.
Yukiko Uekaji Daisuke Nakata Hirokazu Shiga Ayako Jo Iwao Tachi Hiroshi Fukumi Akihito Urano Keiji Terao 《Journal of inclusion phenomena and macrocyclic chemistry》2011,70(3-4):447-451
We have already reported the enhancement of the stability and bioavailability of coenzyme Q10 (CoQ10) oxidized form by γ-cyclodextrin (γCD) complexation. In a series of the studies, we investigated an easy and economical conversion of CoQ10 oxidized form to its reduced form in complex powder, using inexpensive vitamin C (VC) as the reductant. CoQ10 oxidized form or its γCD complex and VC were physically mixed at the molar ratio of 1:0 to 1:50. The mixtures were stored at 60 °C and 75% RH. The sampling was made at certain interval, and both CoQ10 oxidized and reduced form contents were measured by high performance liquid chromatography (HPLC). The result shows that the conversion ratio to CoQ10 reduced form in γCD complex was significantly higher than that of non-inclusion compound (ca. 80% versus ca. 30% at the maximum). It was also confirmed that CoQ10 reduced form in γCD complex remains as stable as its oxidized form in γCD complex. Free radical scavenging potential of partially reduced CoQ10–γCD complex was assayed with 1,1-diphenyl-2-picrylhydrazyl (DPPH). 相似文献
296.
Misae Kanai Tomoya Hirano Isao Azumaya Iwao Okamoto Hiroyuki Kagechika Aya Tanatani 《Tetrahedron》2012,68(13):2778-2783
The conformation of N-phenylbenzohydroxamic acid has been reported to change depending on the solvent properties. Here, we newly synthesized N-phenylbenzohydroxamic acid derivative, which contains two pyrene moieties separated from the phenyl rings by ethylene linkers. It showed solvent-dependent conformational change, and its fluorescence was also solvent-dependent, that is, only monomer fluorescence of pyrene was observed in DMSO or DMF, whereas the excimer fluorescence was observed in CH2Cl2 or CHCl3. Thus, the structural characteristics could be converted to fluorescence change as output, which would be a good candidate as a fluorescent sensor. 相似文献
297.
Masatoshi Shibuya Fabio Pichierri Masaki Tomizawa Shota Nagasawa Iwao Suzuki Yoshiharu Iwabuchi 《Tetrahedron letters》2012,53(16):2070-2073
We have developed azaadamantane-type nitroxyl radicals (AZADOs) and azabicyclo-type nitroxyl radicals (ABNOs) as highly active alcohol oxidation catalysts. Herein, the electrochemical properties of these nitroxyl radicals were investigated by measuring their formal potentials using cyclic voltammetry (CV). The redox potentials were rationalized with the aid of density functional theory (DFT) calculations. A good correlation between the experimental redox potential and the DFT-computed energy differences (ΔE) between nitroxyl radicals and oxoammonium species was obtained, which shows the effectiveness of DFT in predicting the redox potentials of nitroxyl radicals. Redox potential appears to be an important factor of catalytic activity. 相似文献
298.
Iwao Sato 《Linear algebra and its applications》2011,435(5):943-952
Recently, Levine [9] expressed the vertex weighted complexity on spanning trees (with a fixed root) of the directed line graph of a digraph D in terms of the edge weighted complexity on spanning trees (with a fixed root) of D. We present new proofs for two Levine’s Theorems. Furthermore, we express the number of unicycles of the directed line graph of a digraph D in terms of the number of unicycles of D. 相似文献
299.
Shuji Noguchi Haruka Atsumi Yasunori Iwao Toshiyuki Kan Shigeru Itai 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(2):124-127
Nobiletin [systematic name: 2‐(3,4‐dimethoxyphenyl)‐5,6,7,8‐tetramethoxy‐4H‐chromen‐4‐one; C21H22O8] is a flavonoid found in citrus peels, and has been reported to show a wide range of physiological properties, including anti‐inflammatory, anticancer and antidementia activities. We have solved the crystal structure of nobiletin, which revealed that the chromene and arene rings of its flavone moiety, as well as the two methoxy groups bound to its arene ring, were coplanar. In contrast, the C atoms of the four methoxy groups bound to the chromene ring are out of the plane, making the molecule conformationally chiral. A comparison of the crystal structures of nobiletin revealed that it could adopt a variety of different conformations through rotation of the covalent bond between the chromene and arene rings, and the orientations of methoxy groups bound to the chromene ring. 相似文献
300.