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61.
Kazukiyo Kobayashi Hiroshi Sumitomo Akira Kobayashi Toshihiro Akaike 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5-7):655-667
Polystyrene derivatives with lactose, glucose, maltose, maltotriose, maltopentaose, and maltoheptaose on each benzene ring were prepared by the radical polymerization of a new class of macromers synthesized by coupling the corresponding oligosaccharide lactones with p-vinylbenzylamine. These polymers consisting of amphiphilic structural units were water-soluble, and organic solutes were bound to hydrophobic microenvironments of the polymers in water. α-D-Glucopyranose-carrying polymers were recognized and precipitated by concanavalin A. Cultivation of liver cells (hepatocytes) was attempted using culture dishes whose surface was coated with lactose-, glucose-, maltose-, and maltotriose-carrying polystyrenes. It has been found that a lactose-carrying polystyrene (PVLA) is a useful surface material for hepatocyte culture. 1) Highly specific adhesion of hepatocytes was attained for PVLA-coated dishes with or without serum supplement. 2) The cell adhesion was a threshold phenomenon with respect to the PVLA concentration on the dish. 3) The cell adhesion was effectively inhibited when hepatocytes were treated with PVLA molecules in the medium prior to culture. 4) The adhesion was not inhibited by albumin, an adhesion-inhibitory protein in serum. These findings suggest that pendent galactose residues of a PLVA molecule functioned as a strong recognition determinant for hepatocytes. We assume that multi-antennary, high-density galactose residues of PVLA are attributed to the specific adhesion of hepatocytes. 相似文献
62.
Nobuyuki Ichinose Masahide Hagiri Jun-ichiro Kinugasa Nobuyuki Shichi Toshihiro Nakayama 《Research on Chemical Intermediates》2013,39(1):425-435
A charge-transfer (CT) complex of NOBF4 and hexamethoxybenzene (HMB), which gives out HMB?+ as a “fluorescent radical cation probe,” upon one-electron oxidation, has been designed to explore the excited state dynamics of contact radical ion pairs by laser-induced fluorescence and femtosecond transient absorption spectroscopic techniques. The acetonitrile solution of the CT complex showed weak fluorescence with a similar spectrum to that observed for free excited HMB radical cation (HMB?+*), suggesting the formation of HMB?+* upon the one-photonic excitation of the CT complex. The laser-power dependence of the fluorescence intensity supported the one-photonic excitation event. We have also observed a short-lived transient species but no long-lived species by femtosecond laser flash photolysis of the CT complex. The lifetime (6.5 ps) was in good accordance with its fluorescence quantum yield (2.5 × 10?5) and was able to assign the transient species to the fluorescent state, an excited radical ion pair [HMB ?+*/NO?]. All the events were completed within the inner sphere and the short lifetime of the transient species could be attributed to rapid back-electron transfer. It is concluded that the excited radical cation character in the excited state of the CT complex originates from the radical ion character in the CT complex in the ground state and that a relatively long lifetime of HMB?+* facilitates its observation even in the contact ion pair. 相似文献
63.
Akika Futamura Asuka Uemura Takeshi Imoto Dr. Yusuke Kitamura Dr. Hirotaka Matsuura Dr. Chun‐Xia Wang Toshiki Ichihashi Dr. Yusuke Sato Prof. Dr. Norio Teramae Prof. Dr. Seiichi Nishizawa Prof. Dr. Toshihiro Ihara 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(32):10526-10535
We propose a binary fluorimetric method for DNA and RNA analysis by the combined use of two probes rationally designed to work cooperatively. One probe is an oligonucleotide (ODN) conjugate bearing a β‐cyclodextrin (β‐CyD). The other probe is a small reporter ligand, which comprises linked molecules of a nucleobase‐specific heterocycle and an environment‐sensitive fluorophore. The heterocycle of the reporter ligand recognizes a single nucleobase displayed in a gap on the target labeled with the conjugate and, at the same time, the fluorophore moiety forms a luminous inclusion complex with nearby β‐CyD. Three reporter ligands, MNDS (naphthyridine–dansyl linked ligand), MNDB (naphthyridine–DBD), and DPDB (pyridine–DBD), were used for DNA and RNA probing with 3′‐end or 5′‐end modified β‐CyD – ODN conjugates. For the DNA target, the β‐CyD tethered to the 3′‐end of the ODN facing into the gap interacted with the fluorophore sticking out into the major groove of the gap site ( MNDS and DPDB ). Meanwhile the β‐CyD on the 5′‐end of the ODN interacted with the fluorophore in the minor groove ( MNDB and DPDB ). The results obtained by this study could be a guideline for the design of binary DNA/RNA probe systems based on controlling the proximity of functional molecules. 相似文献
64.
Masahide Tominaga Hiroyuki Ukai Kosuke Katagiri Kazuaki Ohara Kentaro Yamaguchi Isao Azumaya 《Tetrahedron》2014
Five macrocyclic molecules (1–5) were efficiently synthesized from the dimerization and trimerization of di-substituted adamantane derivatives, which were composed of three different aromatic units and two different linker groups. Three single-crystals were obtained from these macrocyclic molecules, including a set of pseudopolymorphs (3a and 3b) of macrocycle 3 and another macrocycle 5 (5a). Single crystal X-ray analysis revealed that the three monocyclic compounds were rectangular or square in shape with solvent molecules in the cavity. Macrocycle 3 in 3a formed stacks to produce tubular structures with channels that assembled into three-dimensional networks through CH/π interactions. 相似文献
65.
Akemi Umeyama Chihiro Ohta Yukari Shino Minori Okada Yukari Nakamura Tatsuya Hamagaki Hiroshi Imagawa Masami Tanaka Aki Ishiyama Masato Iwatsuki Kazuhiko Otoguro Satoshi Ōmura Toshihiro Hashimoto 《Tetrahedron》2014
During the search for new antitrypanosomal drug leads, three new antitrypanosomal compounds, hexatenuins A–C (1–3), were isolated from the fruiting body of Hexagonia tenuis. 1 and 3 possessed an unusual malonate half-ester functional group at C-3 position, and 1 and 2 had a spirostructure in the side-chain. Their structures were elucidated using MS analyses, extensive 2D-heteronuclear NMR data interpretation. Compounds 1–3 showed in vitro antitrypanosomal activity against Trypanosoma brucei brucei with IC50 values of 0.57, 8.60 and 5.62 μg/ml, respectively. 相似文献
66.
Suenaga Yuma Kawano Hiroaki Takamatsu Toshihiro Matsumura Yuriko Ito Norihiko Iwasawa Atsuo Okino Akitoshi 《Plasma Chemistry and Plasma Processing》2022,42(3):575-586
Plasma Chemistry and Plasma Processing - Atmospheric low-temperature plasma has received attention for application in disinfection methods. In this study, we develop a plasma bubbling method as a... 相似文献
67.
68.
Seawater bittern (nigari) is a concentrated solution remaining after the crystallization process of salt that has been used as a coagulant for tofu. Recently, various nigari products are distributed in the East Asia. To clarify the properties of nigari products, major mineral composition of six nigari products was determined. Then, effects of the nigari on the browning and antioxidant activity during the glucose/lysine Maillard reaction were investigated. Though the predominant cation was Mg2+, the content was varied by each product (0.88–6.49 mol/L). The other major ion contents were also varied. Each 0.5 mol/L of d-glucose and l-lysine were incubated with the nigari (5–50 % (v/v)) or nigari-related salts (1 or 2 mol/L). The browning (OD at 465 nm) and antioxidant activity (1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging capacity and ferrous-reducing power) were increased remarkably by the nigari containing high Mg2+ content. The browning tended to be high with sulfates (Na2SO4, (NH4)2SO4). On the other hand, high content of MgCl2 decreased slightly the browning and antioxidant activity. These results suggest that the reaction and antioxidant activities were affected not only by salinity and cations but also by anions and other elements in the nigari. 相似文献
69.
70.
The stabilizing structure of cationic surfactant-protected platinum clusters in water and tertiary amine-protected rhodium clusters in chloroform, prepared by photo- and hydrogen-reduction, respectively, was investigated. These nanoscopic noble metal clusters present a narrow size distribution and are stable. The structural information of protective organic molecules on the surface of metal clusters was studied by transmission electron microscopy and hydrodynamic radius measurements according to the Taylor dispersion method. The size of the entire cluster with the protective layer surrounding the metal surface, obtained as Stokes' radii by the Taylor dispersion method, is considered to be fairly consistent with the sum of the naked particle size, obtained by transmission electron micrographs, and the size of the adsorbed protective layer, supporting the conformational information. 相似文献