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991.
Sou Kikuchi Kayo Okada Yuko Cho Shinichiro Yoshida Eunsang Kwon Mari Yotsu-Yamashita Keiichi Konoki 《Tetrahedron》2018,74(27):3742-3747
Marine sponge Halichondria okadai is a source of numerous toxic secondary metabolites, which are considered as products of the symbiotic species associated with the sponge. In this study, we tested 720 culture conditions and purified 48 sponge-associated microbes. The ethyl acetate extract from the liquid culture of each species was tested for cytotoxicity, hemolytic activity, and brine shrimp lethal activity. Lysiformine (1) was isolated from Lysinibacillus fusiformis and its structure was determined by HRMS and NMR. 相似文献
992.
Tomoko Okada Arisa Kimura Hiroshi Miura Toshinori Nishiyama Masako Mori Jyunya Suzuki 《Journal of carbohydrate chemistry》2013,32(7):584-592
Fusion of human immunodeficiency virus (HIV) to the cell membrane occurs by the specific binding of an envelope protein of HIV-1 (gp120 and gp160) and a glycosphingolipid of the cell membrane. In this study, quantitative and array-based affinity evaluation of gp120 and gp160 was performed by surface plasmon resonance (SPR) and the SPR imaging technique using a substrate immobilized with glycolipid-like compounds (Gb3, GM3, and Lac). Quantitative affinity evaluation showed that gp160 specifically bound to Gb3 and Lac compared with GM3, whereas gp120 showed lower binding affinity and specificity. Array-based evaluation showed that gp160 binds to Gb3 more favorably than Lac and GM3. 相似文献
993.
Dr. Yoko Sakata Masahiro Okada Munehiro Tamiya Prof. Shigehisa Akine 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(34):7595-7601
We propose post-metalation modification as a useful strategy to control the guest recognition behavior of a metal-containing macrocyclic host. This is based on the ligand exchange of the axial ligands of a cobalt(III) dinuclear macrocyclic host, [LCo2X4]2+ (X=axial amine ligand). Four piperidine ligands in [LCo2(pip)4]2+ (pip=piperidine) were site-selectively replaced with primary amines. The competitive experiments revealed that the order of the affinity toward the cobalt centers in [LCo2X4]2+ is primary amine > secondary amine > tertiary amine and that the piperidine-coordinating complex, [LCo2(pip)4]2+, was reasonably reactive among the isolable complexes. Indeed, two piperidine ligands at the diagonal positions in [LCo2(pip)4]2+ were site-selectively replaced with pyridine or acetate ion. The replacement of piperidine with acetate ion significantly enhanced the recognition ability towards Na+. 相似文献
994.
Yoshihiro Hayashiuchi Takeshi Hagihara Yusuke Kojima Takayoshi Yamamoto Sigehiro Owaki Toichi Okada 《辐射效应与固体损伤》2013,168(2):645-650
Abstract Deformation Luminescence(DL) is studied on KCl crystal colored by γ-irradiation. The spectra analysis of DL and thermoluminescence reveals that F-center plays a role as electron donor through the interaction with moving dislocation and V2-center is a probable luminescence center. A theory is presented for understanding the deformation rate and temperature dependences of DL intensity. 相似文献
995.
Dr. Hitoshi Kasai Dr. Tatsuya Murakami Yoshikazu Ikuta Yoshitaka Koseki Dr. Koichi Baba Prof. Hidetoshi Oikawa Prof. Hachiro Nakanishi Dr. Masahiro Okada Mitsuru Shoji Prof. Minoru Ueda Prof. Hiroshi Imahori Prof. Mitsuru Hashida 《Angewandte Chemie (International ed. in English)》2012,51(41):10315-10318
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997.
A Structurally Variable Porous Organic Salt Based on a Multidirectional Supramolecular Cluster
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Tetsuya Miyano Naoki Okada Ryunosuke Nishida Dr. Atsushi Yamamoto Dr. Ichiro Hisaki Prof. Dr. Norimitsu Tohnai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(43):15430-15436
A porous organic salt (POS) composed of 2‐sulfophenyl anthracene (2‐SPA) and triphenylmetylamine (TPMA) forms five types of porous crystals, POS‐a–e, by recognizing subtle differences in the molecular structure of incorporated guest molecules. This structurally variable POS was hierarchically designed on the basis of a supramolecular cluster with a directionally flexible linker formed by the organic salt. X‐ray crystallographic analysis reveals that the salt forms six conformers attributable to rocking and rotational motions of the phenylene group in 2‐SPA. The clusters form POS crystals through different porous networks according to the conformers. The POS crystals show a wide range of fluorescence spectra that are responsive to differences in the molecular and electronic structure of the guest molecule. This remarkable behavior has potential application in sensitive chemical sensors that are responsive to slight differences in molecular structures. 相似文献
998.
Modulated Luminescence of a Stable Open‐Shell Triarylmethyl Radical: Effects of Chemical Modification on Its Electronic Structure and Physical Properties
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Dr. Tetsuro Kusamoto Shun Kimura Yasuyo Ogino Chie Ohde Prof. Dr. Hiroshi Nishihara 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(49):17725-17733
The open‐shell luminescent (3,5‐dichloro‐4‐pyridyl)bis(2,4,6‐trichlorophenyl)methyl (PyBTM) radical contains a nitrogen atom that behaves as a stimulus‐responsive site. Chemical modification at this nitrogen atom, such as coordination of B(C6F5)3 or methylation, shifts the emission maximum to the low‐energy region and increases the reduction potential. The emission colour may be regulated by the reversible Lewis acid–base reaction between B(C6F5)3 and PyBTM. Comparison of the optical and electrochemical properties of the radicals with the electronic structures calculated by density functional theory has indicated that the chemical modification decreased the energy level of the β‐singly occupied molecular orbital, a key orbital in determining the optical and electrochemical properties of such systems. 相似文献
999.
1000.