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1.
The spin content of the proton is investigated by studying the flavor singlet axial structure of the nucleon in a non-topological chiral soliton model. In order to construct a nucleon state we used the generator coordinate projection method as well as a coherent state for the meson wave function. Using a standard set of parameters we found the value g A 0 ? 0.44 for the flavor singlet axial vector coupling constant. This result is not far from that of a typical valence quark model. 相似文献
2.
Hiroyuki Higuchi Kazuhiro Takatsu Tetsuo Otsubo Yoshiteru Sakata Soichi Misumi 《Tetrahedron letters》1982,23(6):671-672
A novel cage compound was obtained by irradiation of a quadruple-layered dithiacyclophane and showed thermally reverse reaction. 相似文献
3.
Nishida H Miyazaki Y Kitamura Y Ohashi M Matsusue T Okamoto A Hosaka Y Ohnishi S Mochizuki H 《Chemical & pharmaceutical bulletin》2001,49(10):1237-1244
Intravascular clot formation is an important factor in a number of cardiovascular diseases. Therefore, the prevention of blood coagulation has become a major target for new therapeutic agents. One attractive approach is the inhibition of factor Xa (FXa), which is a key enzyme in coagulation cascade responsible for the generation of thrombin by limited proteolysis of its zymogen, prothrombin. We have investigated 1-arylsulfonyl-3-piperazinone derivatives, containing a 4-(piperidino)pyridine group in place of guanidino and/or amidino groups, and discovered compound M55113 (30a: 4-[(6-Chloro-2-naphthalenyl)sulfonyl]-1-[[1-(4-pyridinyl)-4-piperidinyl]methyl]piperazinone), as a potent inhibitor of FXa (IC50=0.06 microM) with high selectivity for FXa over trypsin and thrombin. 相似文献
4.
Synthesis and structures of the title compounds 2a–d are described. In spite of non-parallel orientation of the two base rings, fairly large hypochromism was observed for 2a–d. 相似文献
5.
6.
Victor V. Borovkov Michael Anikin Kiyotaka Wasa Yoshiteru Sakata 《Photochemistry and photobiology》1996,63(4):477-482
Abstract— Structurally controlled aggregation course for five porphyrins (etioporphyrin [EP], 5-mono- and 5,15-di-[ p -tol-yl]etioporphyrin [TP and DTP], 5,10,15,20-tetrakis[ p -tol-y1]porphin [TTP], and 5,10,15,20-tetrakis[3,5-di- tert -bu-tylphenyl]porphin [TBP]) in dipalmitoyl-phosphatidyl-choline liposomes has been monitored by fluorescence and absorption spectroscopy. While TBP shows no tendency to aggregate in liposomes, EP, TP, DTP and TTP form a porphyrin-enriched domain in membrane interior with time. The further aggregation steps within porphyrin clusters resulting in formation of stacked porphyrin aggregates have been observed for EP, TP and DTP. 相似文献
7.
Yoshihisa Kurasawa Tomoyoshi Hosaka Yuko Matsumoto Aiko Ishikura Kazue Ikeda Atsushi Takada Ho Sik Kim Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1994,31(6):1697-1700
The reaction of 7-chlorotetrazolo[1,5-α]quinoxaline 5-oxide 6a with acetic anhydride gave 7-chloro-5-(7-chlorotetrazolo[1,5-α]quinoxalin-4-yl)-4,5-dihydro-4-oxotetrazolo[1,5-α]quinoxaline 7a , while the reaction of 7-chloro-1,2,4-triazolo[4,3-α]quinoxaline 5-oxide 6b with acetic anhydride afforded 7-chloro-5-(7-chloro-1,2,4-triazolo[4,3-α]quinoxalin-4-yl)-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 7b and 7-chloro-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 8b . The reaction of compound 6a or 6b with acetic anhydride/acetic acid provided 7-chloro-4,5-dihydro-4-oxo-tetrazolo[1,5-α]quinoxaline 8a or compound 8b , respectively. 相似文献
8.
Haruhisa Kikuchi Yuko Sahashi Asami Haganuma Yoshiteru Oshima 《Tetrahedron letters》2004,45(33):6225-6228
Paecilomycine A (1), B (2), and C (3) were isolated from cultivated fruiting bodies of Paecilomyces tenuipes (Isaria japonica), which is a popular entomopathogenic fungus used in folk medicine and health foods in China, Korea, and Japan. The structures of 1-3 were deduced from their spectroscopic data and their absolute configurations were elucidated by preparing their MPA esters. Compound 1 showed activity in the neurotrophic factor biosynthesis in glial cells. 相似文献
9.
Hosaka S Sato M Ozawa Y Hamada C Takahashi Y Kitamori N 《Chemical & pharmaceutical bulletin》2005,53(5):503-507
Manidipine dihydrochloride or benidipine hydrochloride will change to hydrate form in part, when differential scanning calorimetric (DSC) measurement is carried out together with lactose monohydrate. This interaction was accelerated by compressing their mixture. It can be suggested that the interaction may cause by the disruption of crystal structure of lactose monohydrate due to compression to set free of water molecules. A new DSC peak at 170 degrees C, which was not observed in each component, appeared in DSC measurement of a mixture. This will be based on hydrate formed by the interaction, i.e., movement of water molecules. The profile of the plotting of the DSC peak area ratio before and after compression against the compression force changed by the molar ratio of lactose monohydrate in a mixture. In the case of low molar ratio of lactose monohydrate, profiles for manidipine dihydrochloride and benidipine hydrochloride differed from each other. This will be because manidipine dihydrochloride is stickier than benidipine hydrochloride. The profile for manidipine dihydrochloride became more gradual and showed lag compression force region when the amount of addition of the lubricant, magnesium stearate in a mixture increased. The endothermic peak area at 170 degrees C for manidipine dihydrochloride was larger than that for benidipine hydrochloride. It should be suggested that benidipine hydrochloride is easier to be transformed to its hydrate than manidipine dihydrochloride. 相似文献
10.