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61.
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Sharvan Kumar Kohshi Yoshida Yusuke Hattori Tomohiro Higashino Hiroshi Imahori Shu Seki 《Chemical science》2022,13(6):1594
The stability of singly or multiply negatively charged π-conjugated organic compounds is greatly influenced by their electronic delocalization. Herein, we report a strategic methodology for isolation of a mysterious compound. The isolated compounds, a pyreno[4,5-b]pyrrole monoanion and pyreno[4,5-b:9,10-b′]dipyrrole dianion, were highly stable under ambient conditions due to high delocalization of the negative charge over multiple electron deficient C N groups and pyrene π-scaffolds and allowed purification by column chromatography. To our knowledge, this is the first report on TCNE type reductive condensation of malononitrile involving pyrene di- and tetraone and formation of pyrenopyrrole. All compounds were characterized by spectroscopic methods and X-ray crystallography. A UV-vis spectroscopic study shows an intense low energy absorption band with a large absorption coefficient (ε).An ambient stable pyreno[4,5-b]pyrrole monoanion and pyreno[4,5-b:9,10-b′]dipyrrole dianion have been isolated and characterized, showing a low energy intense absorption band with the absorption coefficient reaching 7.1 × 104 dm3 mol−1 cm−1. 相似文献
63.
Hongyan Chen Rui Wang Miao Miao Xiaocan Liu Yonghui Ma Katsumi Hattori Peng Han 《Entropy (Basel, Switzerland)》2020,22(11)
In order to find out whether the geomagnetic storms and large-mega earthquakes are correlated or not, statistical studies based on Superposed Epoch Analysis (SEA), significance analysis, and Z test have been applied to the Dst index data and M ≥ 7.0 global earthquakes during 1957–2020. The results indicate that before M ≥ 7.0 global earthquakes, there are clearly higher probabilities of geomagnetic storms than after them. Geomagnetic storms are more likely to be related with shallow earthquakes rather than deep ones. Further statistical investigations of the results based on cumulative storm hours show consistency with those based on storm days, suggesting that the high probability of geomagnetic storms prior to large-mega earthquakes is significant and robust. Some possible mechanisms such as a reverse piezoelectric effect and/or electroosmotic flow are discussed to explain the statistical correlation. The result might open new perspectives in the complex process of earthquakes and the Lithosphere-Atmosphere-Ionosphere (LAI) coupling. 相似文献
64.
Hironao Nakayama Masako Nakahara Erina Matsugi Midori Soda Tomoka Hattori Koki Hara Ayuki Usami Chiaki Kusumoto Shigeki Higashiyama Kiyoyuki Kitaichi 《Molecules (Basel, Switzerland)》2021,26(1)
Ferulic Acid (FA) is a highly abundant phenolic phytochemical which is present in plant tissues. FA has biological effects on physiological and pathological processes due to its anti-apoptotic and anti-oxidative properties, however, the detailed mechanism(s) of function is poorly understood. We have identified FA as a molecule that inhibits apoptosis induced by hydrogen peroxide (H2O2) or actinomycin D (ActD) in rat pheochromocytoma, PC12 cell. We also found that FA reduces H2O2-induced reactive oxygen species (ROS) production in PC12 cell, thereby acting as an anti-oxidant. Then, we analyzed FA-mediated signaling responses in rat pheochromocytoma, PC12 cells using antibody arrays for phosphokinase and apoptosis related proteins. This FA signaling pathway in PC12 cells includes inactivation of pro-apoptotic proteins, SMAC/Diablo and Bad. In addition, FA attenuates the cell injury by H2O2 through the inhibition of phosphorylation of the extracellular signal-regulated kinase (ERK). Importantly, we find that FA restores expression levels of brain-derived neurotrophic factor (BDNF), a key neuroprotective effector, in H2O2-treated PC12 cells. As a possible mechanism, FA increases BDNF by regulating microRNA-10b expression following H2O2 stimulation. Taken together, FA has broad biological effects as a neuroprotective modulator to regulate the expression of phosphokinases, apoptosis-related proteins and microRNAs against oxidative stress in PC12 cells. 相似文献
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Keika Hattori Kazuya Yamaguchi Junichiro Yamaguchi Kenichiro Itami 《Tetrahedron》2012,68(37):7605-7612
The palladium- and copper-catalyzed C–H arylation reactions of 1H- and 2H-indazoles with haloarenes are described. A PdCl2/phen/Ag2CO3/K3PO4 catalytic system is effective for the C–H arylation of 1H- and 2H-indazoles with haloarenes, whereas a less expensive CuI/phen/LiOt-Bu catalytic system is applicable to the C–H coupling of substituted 2H-indazoles and iodoarenes. The utility of newly developed catalyst was demonstrated in the rapid synthesis of YC-1 (an antitumor agent) and YD-3 (platelet anti-aggregating agent). These new reactions represent important direct functionalization tools of indazoles, well-known bioisosteres of pharmaceutically important indole core. 相似文献
69.
Grossman RB Hattori K Parkin S Patrick BO Varner MA 《Journal of the American Chemical Society》2002,124(46):13686-13687
A cage-shaped N,N'-diacylaminal crystallizes from some aromatic solvents as "supramolecular chair cyclohexanes", squat cylindrical hexamers with approximate D3d symmetry containing two arene molecules, and from other aromatic and nonaromatic solvents as infinite tapes. A homologous diacylaminal crystallizes only as an infinite tape. The hexamers represent the first examples of cyclic hexamers held together by %@mt;sys@%%@bold@%R%@rsf@%%@sx@%2%@be@%2%@sxx@%%@fn;(;vis;full;auto@%8%@fnx;);vis;full@%-type%@mx@% hydrogen bonds in which the hydrogen-bonded atoms are not coplanar. The diacylaminal represents a new supramolecular synthon, one perhaps more suited to the design of three-dimensional architectures. 相似文献
70.
Assuming naturalness that the quantum corrections to the mass should not exceed the order of the observed mass, we derive and apply model-independent bounds on the anomalous magnetic moments and electric dipole moments of leptons and quarks due to new physics. 相似文献