Chemistry Letters
Online ISSN : 1348-0715
Print ISSN : 0366-7022
ISSN-L : 0366-7022
Volume 49, Issue 12
Displaying 1-20 of 20 articles from this issue
Letter
Editor's Choice
Letter
Highlight Review
  • Takuhiro Otosu, Shoichi Yamaguchi
    2020 Volume 49 Issue 12 Pages 1473-1480
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    Cell membranes are fluidic, and the fluidic properties give unique biological functions to the membranes. Here, we review the application of fluorescence lifetime correlation analyses to elucidate the leaflet-specific lipid diffusion in a model cell membrane supported on a glass surface. Utilization of fluorescence lifetime enables us to discriminate the signals from each leaflet of the lipid bilayer and to analyze the lipid diffusion in a leaflet-specific manner. The results showed that the lipid diffusion in a proximal leaflet facing a glass surface is sensitive to the strength of the electrostatic interaction between the lipid headgroup and the glass surface whereas that in the distal one is insensitive to it. This clearly indicates that the interleaflet coupling is negligible. Because the strength of the interleaflet coupling is highly relevant to the cooperative formation of functional domains across the bilayer, this work provides an important insight into the lipid dynamics in cell membranes.

    We review the application of fluorescence lifetime correlation analyses to elucidate the leaflet-specific lipid diffusion in a model cell membrane supported on glass. The results showed that lipid diffusion in a proximal leaflet facing a glass surface is sensitive to the strength of the electrostatic interaction between the lipid headgroup and the glass surface whereas that in the distal one is insensitive to it. This suggests that the interleaflet coupling is negligible in mono-unsaturated lipids. Fullsize Image
     
Editor's Choice
Letter
  • Gargi Joshi, Kittima Amornwachirabodee, Maiko K. Okajima, Kosuke Okeyo ...
    2020 Volume 49 Issue 12 Pages 1484-1486
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    Bigels consist of a relatively new group of soft materials, developed using two or more networks to achieve synergistic multifunctionalities. Covalently crosslinked bi-hydrogels from two different polysaccharides were designed by employing a two-step process of crosslinking and drying. The individual hydrogels prepared by crosslinking with divinyl sulphone (DVS), were kept together and left to dry. The evaporation preceded the pendant DVS groups on the surface of the two hydrogels to react and bind. The finally obtained fused xerogel can be stored for a long time and used on demand as an uniaxially swelling bigel. We envision the potential use of such polysaccharide hydrogels to prepare cell-gel constructs or structurally compliant tissues as sensors.

  • Keita Hoshi, Yohei Sanagawa, Ryuta Umebayashi, Atsushi Tabata, Hideaki ...
    2020 Volume 49 Issue 12 Pages 1487-1489
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    We have synthesized and characterized an acceptor-π-donor-π-acceptor type pyridinium salt. The salt exhibited yellow emission with large Stokes shift in solution and was successfully excited by NIR irradiation via two-photon absorption process. In addition, it was found that the usage of the salt as a bioimaging agent for HeLa cells visualizes cell death. The combined use of the salt and a commercially available green fluorescent dye for the detection of live cell viability realized the one-shot fluorescence imaging of live and dead HeLa cells under the single blue excitation.

  • Catur Jatmika, Kazumo Wakabayashi, Ryosei Tamaki, Naoki Akiyama, Ibuki ...
    2020 Volume 49 Issue 12 Pages 1490-1493
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    Ligand exchange reactions between a Hoveyda–Grubbs-type complex and 2-alkoxybenzylidene in a biomolecule assist in the delivery of a ruthenium complex unit to the biomolecule. Complexes having an electron-withdrawing group in their ligands efficiently transfer a ruthenium complex unit onto peptides. This method is also applicable for adenylate kinase, an experimental model protein. The ligand exchange reaction originates from ruthenium-olefin specific interactions and potentially provides a bioorthogonal method for chemical modification of biomacromolecules with transition metal complexes.

  • Won-Young Cha, Jae-yeon Lee, Jinwoo Park, Yun Hee Koo, Juhyun Park, Sh ...
    2020 Volume 49 Issue 12 Pages 1494-1496
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    Conjugated polymer crystals enable us to realize an ideal platform for the highest density-of-state of electrons in valence and conduction bands. Herein we report a facile protocol to prepare crystalline particles (P3HT-CP) of poly(3-hexylthiophene) (P3HT) with clear cubic shapes. Long-range ordering of P3HT has been confirmed by microscopic techniques, suggesting extremely small contribution from amorphous domains in the cubic structures. The comparable electronic absorption spectra of P3HT-CP dispersion and the thin-film of P3HT-CP suggest the suppression of additional structural evolution during solvent evaporation and stable dispersion.

  • Masayuki Sano, Hiroyuki Shimaoka, Naoki Kohira, Yuki Murakami, Hitoshi ...
    2020 Volume 49 Issue 12 Pages 1497-1500
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    Third-generation cephalosporins possess broad spectrum and potent activities against Gram-positive and Gram-negative bacteria. In order to establish a general methodology for improving the oral bioavailability of third-generation cephalosporins, we designed and prepared a series of novel prodrugs of cefetamet using cefetamet pivoxil as a substrate by converting the amino group at the aminothiazole moiety into a series of acyloxymethyl carbamates. Several prodrugs showed higher oral bioavailability than an l-alanyl analogue of cefetamet pivoxil and comparable bioavailability to cefetamet pivoxil.

  • Masayuki Sano, Hiroyuki Shimaoka, Naoki Kohira, Yuki Murakami, Hitoshi ...
    2020 Volume 49 Issue 12 Pages 1501-1503
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    Macrocyclization can help improve pharmacological activity, metabolic stability, cell permeability and oral absorption to create better drug candidates. For example, enhancing the oral absorption of the compounds can allow a change in administration route. We tried to improve the oral bioavailability of ceftriaxone, a third-generation cephalosporin having a unique side chain with a 2,5-dihydro-6-hydroxy-2-methyl-5-oxo-as-triazin-3-yl group at the C-3 position of the cephem nucleus. We prepared novel macrocycles of ceftriaxone by valuable synthetic methods and confirmed their oral bioavailabilities.

  • Beibei Chen, Zhe Dong, Mengjie Zhang, Yuhan Jia, Jin Yang
    2020 Volume 49 Issue 12 Pages 1504-1506
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
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    The separation of oil-water mixtures has attracted widespread attention for addressing increased oil spillage and oil-polluted water. In this study, a novel and low-cost oil-water separation coating material composed of epoxy (EP) and modified sepiolite (SEP) by poly (diallyldimethylammonium chloride) (PDDA) and sodium perfluorooctanoate (SPFO) was fabricated. The as-prepared coating showed excellent superhydrophilic/superoleophobic properties, determined by its micro/nano rough microstructure, hydrophilic groups of PDDA, and oleophobic groups of SPFO, and it is not damaged by friction even after being wetted by water, which was mainly ascribed to EP with good adhesiveness. More importantly, the surface of stainless-steel mesh sprayed with SEP@PDDA-PFO/EP coating became superhydrophilic/superoleophobic, and showed excellent oil-water separation efficiency, which can avoid the deficits of traditional separation materials easily being polluted and difficult to recycle. This research could provide a novel modification method of SEP and promote its application in oil-water separation.

Award Highlight Review
  • Shinichi Komaba
    2020 Volume 49 Issue 12 Pages 1507-1516
    Published: December 05, 2020
    Released on J-STAGE: December 15, 2020
    JOURNAL RESTRICTED ACCESS

    Due to the crucial impact of Li-ion batteries commercialized in 1991, the author had an opportunity to contribute to the research development of lithium battery materials beginning in 1997. These research experiences further provided motivation and opened up a new research field targeting the demonstration of non-aqueous Na-ion batteries later in the career. In 2009, the author’s research group successfully demonstrated 3-volt class charge and discharge of a Na-ion battery, and the increased motivation led to a brand-new 4-volt class K-ion battery. This article overviews our systematic studies of lithium-, sodium-, and potassium-driven redox systems, which synergistically induce accelerated development of new materials for next-generation rechargeable batteries. Our achievement update of layered oxide and hard carbon electrode materials is also described as an effort towards high-energy Na-ion batteries.

    Progressive research of materials for Li-ion battery opened up a new research field targeting Na-ion and K-ion batteries. The author’s research group demonstrated 3-volt class Na-ion battery and 4-volt class brand-new K-ion battery. This article overviews our systematic studies of lithium-, sodium-, and potassium-driven redox systems along with an recent update towards high-energy Na-ion batteries. Fullsize Image
     
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