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排序方式: 共有383条查询结果,搜索用时 15 毫秒
301.
Taku Aiga Yoshiyuki Manabe Keita Ito Tsung‐Che Chang Kazuya Kabayama Shino Ohshima Yoshie Kametani Ayane Miura Hiroto Furukawa Hiroshi Inaba Kazunori Matsuura Koichi Fukase 《Angewandte Chemie (International ed. in English)》2020,59(40):17705-17711
Co‐assembling vaccines composed of a lipidated HER2‐derived antigenic CH401 peptide and either a lipophilic adjuvant, Pam3CSK4, α‐GalCer, or lipid A 506, were evaluated as breast cancer vaccine candidates. This vaccine design was aimed to inherit both antigen multivalency and antigen‐specific immunostimulation properties, observed in reported self‐adjuvanting vaccine candidates, by using self‐assembly and adjuvant‐conjugated antigens. Under vaccination concentrations, respective lipophilic adjuvants underwent co‐assembly with lipidated CH401, which boosted the anti‐CH401 IgG and IgM production. In particular, α‐GalCer was responsible for the most significant immune activation. Therefore, the newly developed vaccine design enabled the optimization of adjuvants against the antigenic CH401 peptide in a simple preparatory manner. Overall, the co‐assembling vaccine design opens the door for efficient and practical self‐adjuvanting vaccine development. 相似文献
302.
303.
Keita Sakamoto Akihiro Hakamata Dr. Arihiro Iwasaki Prof. Dr. Kiyotake Suenaga Prof. Dr. Masashi Tsuda Prof. Dr. Haruhiko Fuwa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(36):8528-8542
Iriomoteolide-2a is a marine macrolide metabolite isolated from a cultured broth of the benthic dinoflagellate Amphidinium sp. HYA024 strain. This naturally occurring substance was reported to show remarkable cytotoxic activity against human cancer cell lines HeLa and DG-75 and in vivo antitumor activity against murine leukemia P388 cell line. Herein, the total synthesis, stereochemical revision, and biological assessment of iriomoteolide-2a are reported in detail. Total synthesis of the proposed structure 1 of iriomoteolide-2a featured a late-stage convergent assembly of three components by a Suzuki–Miyaura coupling, an esterification, and a ring-closing metathesis. However, the NMR data of synthetic 1 were not identical to those of the natural product. Careful analysis of the NMR data of the authentic material and synthesis/NMR analysis of appropriately designed model compounds led to consideration of four possible stereoisomers 2 – 5 as candidates for the correct structure. Accordingly, total syntheses of 2 – 5 were achieved by taking advantage of the convergent strategy, and comparison of the NMR spectra of synthetic 2 – 5 with those of the natural product led to the conclusion that 5 shows the correct relative configuration of iriomoteolide-2a. The absolute configuration of this natural product was finally established through chiral HPLC analysis of synthetic 5 /ent- 5 with the authentic sample. The antiproliferative activity of the synthetic compounds was assessed against HeLa and A549 cells to show that, in contrast to expectation, synthetic 5 and ent- 5 were only marginally active in these cell lines. This work clearly underscores the vital role of total synthesis in the establishment of the structure and biological activity of natural products. 相似文献
304.
Ueyama Kohei Hatta Takuya Okemoto Atsushi Taniya Keita Ichihashi Yuichi Nishiyama Satoru 《Research on Chemical Intermediates》2018,44(1):629-638
Research on Chemical Intermediates - Cyclohexane photocatalytic oxidation was performed over WO3 photocatalysts under visible light irradiation with molecular oxygen. Cyclohexanone and cyclohexanol... 相似文献
305.
Yuichi Ichihashi Megumi Yamaguchi Yo-hei Nishikawa Keita Taniya Shigeru Tsuruya Satoru Nishiyama 《Research on Chemical Intermediates》2010,36(5):463-472
Metal-loaded titanium oxide photocatalysts produced hydrogen in the photodecomposition of water vapor with methane in the
flow reactor. Ag/TiO2 has the highest activity in comparison with other metal-loaded catalysts. The experiment in the absence of methane indicated
that methane could effectively function as a reducing reagent of water. The significant decrease in the hydrogen formation
rate with the time on stream was observed under all reaction conditions. The recalcination and the hydrogen rereduction of
the used catalyst led to the restoration of the activity of the hydrogen formation. The adsorption of products and/or reactants
on the catalyst surface seemed to cause these deactivations of the hydrogen formation. 相似文献
306.
Anne Dolbecq Dr. Jean‐Daniel Compain Pierre Mialane Dr. Jérôme Marrot Dr. Francis Sécheresse Prof. Bineta Keita Dr. Luis Roberto Brudna Holzle Dr. Frédéric Miserque Dr. Louis Nadjo Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(3):733-741
Two new compounds based on O3PCH2PO34? ligands and {MoV2O4} dimeric units have been synthesized and structurally characterized. The dodecanuclear MoV polyoxomolybdate species in (NH4)18[(MoV2O4)6(OH)6(O3PCH2PO3)6]?33 H2O ( 1 ) is a cyclohexane‐like ring in a chair conformation with pseudo S6 symmetry. In the solid state, the wheels align side by side, thus delimiting large rectangular voids. The hexanuclear anion in Na8[(MoV2O4)3(O3PCH2PO3)3(CH3AsO3)]? 19 H2O ( 2 ) has a triangular framework and encapsulates a methylarsenato ligand. 31P NMR spectroscopic analysis revealed the stability of 2 in various aqueous media, whereas the stability of 1 depends on the nature of the cations present in solution. It has been evidenced that the transformation of 1 into 2 occurs in the presence of CH3AsO32? ions. This behavior shows that 1 can be used as a new precursor for the synthesis of MoV/diphosphonate systems. The two complexes were very efficient both as reductants of Pt and Pd metallic salts and as capping agents for the resulting Pt0 and Pd0 nanoparticles. The size of the obtained nanoparticles depends both on the nature of the polyoxometalate (POM; i.e., 1 or 2 ) and on the [metallic salt]/[POM] ratio. In all cases, X‐ray photoelectron spectroscopy (XPS) measurements have revealed the presence of MoVI species that stabilize the nanoparticles and the absence of MoV moieties. Diffuse‐reflectance FTIR spectra of the Pt nanoparticles show that the capping MoVI POMs are identical for both systems and contain the diphosphonato ligand. The colloidal solutions do not show any precipitate and the nanoparticles remain well‐dispersed for several months. The electrochemical reduction of MoV species was studied for 2 . Cyclic voltammetry alone and electrochemical quartz crystal microbalance coupled with cyclic voltammetry show the deposition of a film on the electrode surface during this reduction. 相似文献
307.
308.
Yuki Kitahara Ko Okuyama Keita Ozawa Takuya Suga Seiji Takahashi Toshihiro Fujii 《Journal of Thermal Analysis and Calorimetry》2012,110(1):423-429
Ion-attachment mass spectrometry with a temperature-programed direct probe allows the detection of intact pyrolysis products. It, therefore, offers the opportunity to monitor directly thermal byproducts on a real-time basis and potentially to detect thermally unstable products. With this technique, we investigated the thermal decomposition of polyacrylamide (PAA). Pyrolysis of PAA at around 450?°C produces many products (e.g., amides, imides, nitriles, ketones, aldehydes, and acrylamide oligomers). Acrylamide, which is a possible carcinogen, is produced abundantly in various industries, and, therefore, continues to be a cause for concern. We also investigated the kinetics of the thermal decomposition of PAA, and observed that the degradation of acrylamide obeys Arrhenius kinetics, which allowed us to correlate the rate constant with the absolute temperature and the activation energy. The activation energy of thermal decomposition was calculated from selected ion-monitoring curves of acrylamide. 相似文献
309.
310.