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81.
Dr. Taku Kitanosono Prof. Dr. Shū Kobayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(43):9408-9429
Ever-evolving catalyst advances in synthetic protocols using water as a reaction medium have enriched the understanding of sustainable organic chemistry. Because conventional classification and definitions were ambivalent, it is proposed here that catalytic reactions using water be collectively called to be “in water”, with further classification into seven types. When accelerated in water as heterogeneous mixtures, the reactions can be regarded as following an “on-water” mechanism. The original term “on water” coined by Sharpless is incongruous with catalytic reactions, whereas on-water used in this review covers all the interfaces involving water where chemical reactions are accelerated. As a result of the unconcluded dispute on the antiquated catalyst-free “on water” model, the modified model defines three water layers: water molecules that are oriented to extrude protons toward the oil phase in the inner layer, those enwrapped by a secondary layer, and finally the bulk water layer. In light of the latitudinous outlook on the role of water at the interface, selected examples of reactions, in particular those reported over the past decade, that follow an “on-water” mechanism are reviewed herein. 相似文献
82.
Prof. Dr. Frank Heinrich Aria Salyapongse Akari Kumagai Dr. Fernando G. Dupuy Karpur Shukla Dr. Anja Penk Prof. Dr. Daniel Huster Prof. Dr. Robert K. Ernst Dr. Anna Pavlova Prof. Dr. James C. Gumbart Prof. Dr. Berthony Deslouches Prof. Dr. Y. Peter Di Prof. Dr. Stephanie Tristram-Nagle 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(28):6247-6256
In the quest for new antibiotics, two novel engineered cationic antimicrobial peptides (eCAPs) have been rationally designed. WLBU2 and D8 (all 8 valines are the d -enantiomer) efficiently kill both Gram-negative and -positive bacteria, but WLBU2 is toxic and D8 nontoxic to eukaryotic cells. We explore protein secondary structure, location of peptides in six lipid model membranes, changes in membrane structure and pore evidence. We suggest that protein secondary structure is not a critical determinant of bactericidal activity, but that membrane thinning and dual location of WLBU2 and D8 in the membrane headgroup and hydrocarbon region may be important. While neither peptide thins the Gram-negative lipopolysaccharide outer membrane model, both locate deep into its hydrocarbon region where they are primed for self-promoted uptake into the periplasm. The partially α-helical secondary structure of WLBU2 in a red blood cell (RBC) membrane model containing 50 % cholesterol, could play a role in destabilizing this RBC membrane model causing pore formation that is not observed with the D8 random coil, which correlates with RBC hemolysis caused by WLBU2 but not by D8. 相似文献
83.
Nobutaka Yoshimura Dr. Atsushi Kobayashi Dr. Masaki Yoshida Prof. Masako Kato 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(70):16939-16946
To investigate the effect of the surface structure of dye-sensitized photocatalyst nanoparticles, we prepared three types of RuII-photosensitizer (PS)-double-layered Pt-cocatalyst-loaded TiO2 nanoparticles with different surface structures, Zr- RuCP6 -Zr- RuP6 @N wt %Pt-TiO2, RuCP6 -Zr- RuP6 @N wt %Pt-TiO2, and RuCP2 -Zr- RuP6 @N wt %Pt-TiO2 (N=0.2, 1, and 5), and evaluated their photocatalytic H2 evolution activity in the presence of redox-reversible iodide as the electron donor. Although the driving force of the electron injection from I− to the photo-oxidized RuIII PS is comparable, the activity increased in the following order: RuCP2 -Zr- RuP6 @1 wt %Pt-TiO2 < RuCP6 -Zr- RuP6 @1 wt %Pt-TiO2 < Zr- RuCP6 -Zr- RuP6 @1 wt %Pt-TiO2. The apparent quantum yield of Zr- RuCP6 -Zr- RuP6 @1 wt %Pt-TiO2 in the first hour reached 1 %. Zeta-potential measurements suggest that the surface Zr4+-phosphate groups attracted I− anions to the nanoparticle–solution interface. Our results indicate that the surface modification of dye-sensitized photocatalysts is a promising approach to enhance photocatalytic activity with various redox mediators. 相似文献
84.
85.
Nagwa Abo El-Maali Asmaa Y. Wahman Aref A.M. Aly Ahmed Y. Nassar Douaa M. Sayed 《应用有机金属化学》2020,34(6):e5594
Lanthanide complexes are of increasing importance in cancer diagnosis and therapy. In the present study 1:1 and 1:3 solid complexes of La (III)–5-FU (5-fluorouracil) were prepared and characterized. In solution, the formation of 1:1 La (III) and Eu (III) complexes enabled the enhancement of 5-FU's effectiveness. Binding constants of the 1:1 complexes of both metals were estimated using spectrophotometry and HPLC with fluorescence detection methods. The thermodynamic parameters ΔG ° , ΔH ° and ΔS ° were calculated using differential scanning calorimetry. Evaluation of the cytotoxic activity of the 1:1 La (III)- and Eu (III)–5-FU complexes was performed through two methodologies, trypan blue for cell viability where La (III)- and Eu (III)–5-FU complexes were found to have 52,000 and 80,000 dead cells, respectively, and via flow cytometric analysis to measure the apoptotic values, which were found to be 59.87 and 86.86% respectively. 相似文献
86.
Obydennov Dmitrii L. Simbirtseva Alena E. Sosnovskikh Vyacheslav Y. 《Research on Chemical Intermediates》2022,48(5):2155-2179
Research on Chemical Intermediates - Synthesis of 2-cyano-6-styryl-4-pyrones has been developed on the basis of 6-metylcomanic acid via modifications of the methyl and carboxyl groups. Reactions of... 相似文献
87.
Chehab S. Merroun Y. Ghailane T. Ghailane R. Boukhris S. Akhazzane M. Kerbal A. Souizi A. 《Russian Journal of Organic Chemistry》2019,55(9):1380-1386
Russian Journal of Organic Chemistry - A new strategy has been proposed for the synthesis of 9-arylhexahydroacridine-1,8-diones by three-component condensation of aromatic aldehydes with... 相似文献
88.
Experimental Mechanics - Simulating the deformations of soft tissues has gained importance in recent years due to the development of 3D patient-specific biomechanical models in the context of... 相似文献
89.
90.
Achieving tunable band gaps in a structure by external stimuli is of great importance in acoustic applications. This paper aims to investigate the tunability of band gaps in square-lattice-like elastic periodic structures that are usually not featured with notable band gaps.Endowed with chirality, the periodic structures here are able to undergo imperfection-insensitive large deformation under extension or compression. The influences of geometric parameters on band gaps are discussed via the nonlinear finite element method. It is shown that the band gaps in such structures with curved beams can be very rich and, more importantly, can be efficiently and robustly tuned by applying appropriate mechanical loadings without inducing buckling. As expected, geometry plays a more significant role than material nonlinearity does in the evolution of band gaps. The dynamic tunability of band gaps through mechanical loading is further studied. Results show that closing, opening, and shifting of band gaps can be realized by exerting real-time global extension or compression on the structure. The proposed periodic structure with well-designed chiral symmetry can be useful in the design of particular acoustic devices. 相似文献