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81.
Treatment of 1-chloro-2-methylalkenyl p-tolyl sulfoxides with N-lithio 2-piperidone in THF at room temperature resulted in the formation of 1-chloro-2-(hydroxymethyl)alkenyl p-tolyl sulfides in good yields. This reaction is the first example of the Mislow-Braverman-Evans rearrangement retaining the sulfur atom on the original carbon. 相似文献
82.
Hiroo Nakagawa Yoshiyuki Kani Masanobu Tsuchimoto Shigeru Ohba Hideaki Matsushima Tadashi Tokii 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(1):12-16
In the crystals of bis(pyridine‐N)tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II), [Cu2(C5H11O2Si)4(C5H5N)2], (I), the dinuclear CuII complexes have cage structures with Cu?Cu distances of 2.632 (1) and 2.635 (1) Å. In the crystals of bis(2‐methylpyridine‐N)tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II), [Cu2(C5H11O2Si)4(C6H7N)2], (II), bis(3‐methylpyridine‐N)tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II), [Cu2(C5H11O2Si)4(C6H7N)2], (III), and bis(quinoline‐N)tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II), [Cu2(C5H11O2Si)4(C9H7N)2], (IV), the centrosymmetric dinuclear CuII complexes have a cage structure with Cu?Cu distances of 2.664 (1), 2.638 (3) and 2.665 (1) Å, respectively. In the crystals of catena‐poly[tetrakis(μ‐trimethylsilylacetato‐O:O′)dicopper(II)], [Cu2(C5H11O2Si)4]n, (V), the dinuclear CuII units of a cage structure are linked by the cyclic Cu—O bonds at the apical positions to form a linear chain by use of a glide translation. 相似文献
83.
As plants lack a circulatory system and adaptive immune system, they have evolved their own defense systems distinct from animals, in which each plant cell is capable of defending itself from pathogens. Plants induce a number of defense responses, which are triggered by a variety of molecules derived from pathogenic microorganisms, referred to as microbe-associated molecular patterns (MAMPs), including peptides, proteins, lipopolysaccharide, beta-glucan, chitin, and ergosterol. The interaction between plants and chemicals in the context of plant defense represents a "natural" and simple model for chemogenomics, at the intersection between chemical and biological diversities. For protection of crop plants from diseases, it has been shown to be effective to stimulate the plant immunity by chemical compounds, the so-called "plant defense activators". Combinatorial chemistry techniques can be applied to the search for novel plant defense activators, but it is essential to establish an efficient and reliable screening system suitable for library screening. For studies of the plant immune system, it is difficult to use isolated proteins as biological targets because the receptors for MAMP recognition are largely unknown and even the receptors identified so far are transmembrane proteins. Therefore, screening for novel peptides acting on MAMP receptors from combinatorial libraries must rely on a solution-phase assay using cells as the biological targets. In this review, we introduce the cell-based lawn format assay for identification of peptides acting as plant defense activators from combinatorial peptide libraries. The requirements and limitations in constructing the screening system using combinatorial libraries in the studies of plant sciences are also discussed. 相似文献
84.
Centrifugal partition chromatography (CPC) was applied to separate amphiphilic glycolipids and pseudo-glycolipids synthesized by using cells. Neutral and acidic lipid fractions were isolated by CPC under suitable conditions respectively. Separation of neutral lipid, Gb3-type and Gb4-type oligosaccharide synthesized by using cells, was performed with a two-phase solvent system composed of chloroform-methanol-water at a volume ratio of 5:6:4. On the other hand, separation of acidic lipid, GM3-type oligosaccharide synthesized by using cells, and ganglioside extracted from rat brain were performed with a two-phase solvent system composed of butanol-ethanol-1% acetic acid at a volume ratio of 4:1:5. 8.3mg of Gb3 analogue, 5.1mg of Gb4 analogue, and 19.5mg of GM3 analogue were purified from 3.2l of culture medium obtained by incubation of African green-monkey kidney (Vero) cells with 50 microM n-dodecyl beta-lactoside using CPC. 相似文献
85.
Takatsugu Endo Shota Suzuki Nobukazu Miyagawa Shigeru Takahara 《Journal of photochemistry and photobiology. A, Chemistry》2008,200(2-3):181-186
We present N-(p-anilinesulfonyloxy)-1,8-naphthalimide (ASNI) as fluorescence imaging material based on a novel fluorescence imaging mechanism. ASNI is composed of two functional moieties in one molecule: an acid-reactive fluorescence probe and a photoacid generator (PAG). When ASNI is photoirradiated, a bond in the PAG moiety breaks and an acid is generated. The fluorescence probe moiety then detects the acid and fluoresces. We call this novel mechanism a self-contained photoreaction (SCP). The photophysical properties and photoreactivity of ASNI were measured and compared with those of a prototype PAG, N-(phenylsulfonyloxy)-1,8-naphthalimide. These were well represented by density functional theory calculations. SCP permits one-step fluorescence imaging without any wet or dry developing process. 相似文献
86.
Shimanouchi T Sasaki M Hiroiwa A Yoshimoto N Miyagawa K Umakoshi H Kuboi R 《Colloids and surfaces. B, Biointerfaces》2011,88(1):221-230
In this study, we investigated the dynamics of a membrane interface of liposomes prepared by eight zwitterionic phosphatidylcholines in terms of their headgroup mobility, with spectroscopic methods such as dielectric dispersion analysis (DDA), fluorescence spectroscopy. The DDA measurement is based on the response of the permanent dipole moment to a driving electric field and could give the information on the axial rotational Brownian motion of a headgroup with the permanent dipole moment. This motion depended on kinds of phospholipids, the diameter of the liposomes, and the temperature. The activation energy required to overcome the intermolecular force between headgroups of phospholipids depended on the strength of the interaction between headgroups such as hydrogen bonds and/or dipole-dipole interaction. Hydration at the phosphorous group of phospholipid and the molecular order of lipid membrane impaired the interaction between headgroups. Furthermore, the hydrophobicity of membrane surface increased parallel to the increase in headgroup mobility. It is, therefore, concluded that hydration of headgroup promoted its mobility to make the membrane surface hydrophobic. The lipid membrane in liquid crystalline phase or the lipid membrane with the larger curvature was more hydrophobic. 相似文献
87.
Furusho Y Goto H Itomi K Katagiri H Miyagawa T Yashima E 《Chemical communications (Cambridge, England)》2011,47(35):9795-9797
A tetranuclear Cu(I) double-stranded helicate was synthesized from ketimine-bridged tris(bipyridine) ligands and Cu(I) ions, and the racemate was successfully resolved by diastereomeric salt formation using an optically pure phosphate anion followed by anion exchange with NaPF(6) without racemization. 相似文献
88.
Kazuhiro Kobayashi Kenichi Hashimoto Hiroo Hashimoto Hideaki Kondo Hisatoshi Konishi 《Helvetica chimica acta》2011,94(7):1277-1282
A novel method is reported for the synthesis of 9,9‐disubstituted 9H‐pyrrolo[1,2‐a]indoles. Cyclization of 1‐[2‐(1‐aryl(or methyl)ethenyl)phenyl]‐1H‐pyrroles, which can be easily prepared from 2‐(1‐aryl(or methyl)ethenyl)anilines, proceeds smoothly, in general, at 0° in the presence of a catalytic (or an equimolar) amount of HI in MeCN to provide the desired products. 相似文献
89.
Pengju Pan Zhichao Liang Nobuo Nakamura Toshio Miyagawa Yoshio Inoue 《Macromolecular bioscience》2009,9(6):585-595
In this study, uracil has been introduced as the nucleating agent (NA) for bacterially synthesized poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyhexanoate)] (PHBHHx) copolymers with HHx content of 5, 10, 18 mol‐%, and poly(3‐hydroxybutyrate) (PHB) homopolymer for the first time. Its effect was compared with the conventional NA of PHB, that is, boron nitride (BN), and two other naturally occurring pyrimidine derivatives, i.e., thymine and cytosine. The effects of uracil on the crystallization kinetics, melting behavior, spherulite morphology, and crystalline structure of PHBHHx and PHB were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), and wide‐angle X‐ray diffraction (WAXD). Uracil and BN exhibit the comparable nucleation efficiency on the crystallization of PHB, whereas uracil shows much more effective nucleation ability than BN for PHBHHx copolymers. With incorporation of 1 wt.‐% uracil, PHBHHx with 0–10 mol‐% HHx units can finish crystallization upon cooling at 10 °C · min?1. The crystallization half‐times (t1/2) of all the PHB and PHBHHx samples decrease significantly with presence of uracil. The crystallization rate of polymers further enhances with increase in uracil concentration. With addition of 1 wt.‐% uracil, the t1/2 value of PHBHHx with 10 mol‐% HHx units melt‐crystallizing at 80 °C decreases to ≈4.0% of the neat polymer, and the nucleation density increases by 3–4 orders of magnitude. The incorporation of uracil has no discernable effect on the crystalline structure of PHBHHx, as evidenced by WAXD results. It was proposed that the nucleation mechanism of the uracil/PHBHHx (or PHB) system might be the epitaxial nucleation.
90.
Masahide Takahashi Masaru Suzuki Yuya Miyagawa Rie Ihara Yomei Tokuda Toshinobu Yoko Takashi Nemoto Seiji Isoda 《Journal of Sol-Gel Science and Technology》2010,54(3):319-324
Photo-curable vinyl modified silicate-phosphate alternating copolymers were prepared by a direct condensation of organochlorosilane and organophosphoric acid in a solvent-free condition. The obtained copolymers have complete alternating copolymer structure of silicate and phosphate unit, where the main oxo chain consist of –(Si–O–P–O) n -network. They exhibited an excellent solubility of ionic species such as ionic organic dyes. It was also demonstrated the photo-reduction of Au+ ions to form Au nano particles for plasmonics applications. Micro patterns were also fabricated by soft lithographic processes. These results indicate that the photo-curable alternating copolymers are one of promising materials for advanced optical information processing devices. 相似文献