排序方式: 共有180条查询结果,搜索用时 15 毫秒
171.
Ono M Takara Y Egami M Uranaka K Yoshimitsu H Matsushita S Fujiwara Y Ikeda T Nohara T 《Chemical & pharmaceutical bulletin》2006,54(2):237-239
Two new steroidal alkaloid glycosides, esculeosides C and D, have been isolated from the ripe fruit of Cherry tomato [Lycopersicon esculentum var. cerasiforme (DUNAL) ALEF.], along with three known steroidal alkaloid glycosides, esculeoside A, esculeoiside B, and lycoperoside G. Their chemical structures were determined on the basis of spectroscopic data. 相似文献
172.
Yamana K Fukunaga Y Ohtani Y Sato S Nakamura M Kim WJ Akaike T Maruyama A 《Chemical communications (Cambridge, England)》2005,(19):2509-2511
A pyrene-excimer-forming probe allowed the easy and sensitive detection of a single base mismatch in target DNA. This was due to the faster strand exchange rate compared to a fully-matched target. 相似文献
173.
Matsushita S Yanai Y Fusyuku A Ikeda T Ono M Nohara T 《Chemical & pharmaceutical bulletin》2007,55(7):1079-1081
It has been revealed that the absolute configurations at C-22 of 23-hydroxyspirostane and 23-hydroxyspirosolane could be unambiguouly judged by the (1)H- and (13)C-NMR spectroscopies. 相似文献
174.
Mitsunori Oda Kazutaka Ogura Sayaka Kishi Kunihide Fujimori Noritaka Abe 《Tetrahedron letters》2007,48(26):4471-4475
The title azaazulene 3 was synthesized either by reaction of tropone with N-{(2-pyridyl)acetyl}pyridinium iodide in the presence of ammonium acetate or by palladium-catalyzed cross-coupling between 2-halo-1-azaazulene and 2-substituted pyridine. The compound shows relatively stronger basicity compared with 2,2′-bipyridyl. While 3 showed no emission from the S1 state but from the S2 state like azulene does, the protonated species of 3 exhibited emission from the S1 state. Cationic metal-dependent absorption and emission relating to complexation were also studied. 相似文献
175.
Shibata S Zhang Z Korotkov KV Delarosa J Napuli A Kelley AM Mueller N Ross J Zucker FH Buckner FS Merritt EA Verlinde CL Van Voorhis WC Hol WG Fan E 《Analytical and bioanalytical chemistry》2011,401(5):1585-1591
Ultrafiltration provides a generic method to discover ligands for protein drug targets with millimolar to micromolar K(d), the typical range of fragment-based drug discovery. This method was tailored to a 96-well format, and cocktails of fragment-sized molecules, with molecular masses between 150 and 300 Da, were screened against medical structural genomics target proteins. The validity of the method was confirmed through competitive binding assays in the presence of ligands known to bind the target proteins. 相似文献
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177.
Akine S Hotate S Matsumoto T Nabeshima T 《Chemical communications (Cambridge, England)》2011,47(10):2925-2927
The left-handed isomer of the helical complex [LZn(3)La(OAc)(3)] was spontaneously enriched from 50 : 50 to 87 : 13 when the quasiracemate crystals were dissolved. The invertible helicity of [LZn(3)La(OAc)(3)] (global chirality) helps the quasiracemate formation and the fixed point chirality of the R,R-cyclohexanediamine moiety (local chirality) effectively controls the global chirality in solution. 相似文献
178.
Dr. Tomohiro Seki Sayaka Kurenuma Prof. Dr. Hajime Ito 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(48):16214-16220
We report the luminescent color tuning of a new complex, 2‐benzothiophenyl(4‐methoxyphenyl isocyanide)gold(I) ( 1 ), by using a new “polymorph doping” approach. The slow crystallization of the complex 1 afforded three different pure polymorphic crystals with blue, green, and orange emission under UV‐light irradiation. The crystal structures of pure polymorphs of 1 were investigated in detail by means of single‐crystal X‐ray analyses. Theoretical calculations based on the single‐crystal structures provided qualitative explanation of the difference in the excited energy‐levels of the three polymorphs of 1 . In sharp contrast, the rapid precipitation of 1 , with the optimized conditions reproducibly afforded homogeneous powder materials showing solid‐state white‐emission with Commission Internationale de l’Éclairage (CIE) 1931 chromaticity coordinates of (0.33, 0.35), which is similar to pure white. New “polymorphic doping” has been revealed to be critical to this white emission through spectroscopic and X‐ray diffraction analyses. The coexistence of the multiple polymorphs of 1 within the homogeneous powder materials and the ideal mixing of multiple luminescent colors gave its white emission accompanied with energy transfer from the predominant green‐emitting polymorph to the minor orange‐emitting polymorph. 相似文献
179.
Dr. Tomoyuki Ikai Namiki Mishima Takehiro Matsumoto Sayaka Miyoshi Dr. Kosuke Oki Prof. Eiji Yashima 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2024,136(10):e202318712
Synthetic breakthroughs diversify the molecules and polymers available to chemists. We now report the first successful synthesis of a series of optically-pure 2,2′-tethered binaphthyl-embedded helical ladder polymers based on quantitative and chemoselective ladderization by the modified alkyne benzannulations using the 4-alkoxy-2,6-dimethylphenylethynyl group as the alkyne source, inaccessible by the conventional approach lacking the 2,6-dimethyl substituents. Due to the defect-free helix formation, the circular dichroism signal increased by more than 6 times the previously reported value. The resulting helical secondary structure can be fine-tuned by controlling the binaphthyl dihedral angle in the repeating unit with variations in the 2,2′-alkylenedioxy tethering groups by one carbon atom at a time. The optimization of the helical ladder structures led to a strong circularly polarized luminescence with a high fluorescence quantum yield (28 %) and luminescence dissymmetry factor (2.6×10−3). 相似文献
180.