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991.
Bioisosteric Exchange of C
‐Chloro and Methyl Substituents: Synthesis and Initial Biological Studies of Atpenin A5 Analogues 下载免费PDF全文
Simon Krautwald Dr. Christian Nilewski Dr. Mihoko Mori Prof. Dr. Kazuro Shiomi Prof. Dr. Satoshi Ōmura Prof. Dr. Erick M. Carreira 《Angewandte Chemie (International ed. in English)》2016,55(12):4049-4053
Asymmetric synthesis and initial biological studies of two analogues of a naturally occurring chlorinated antifungal agent, atpenin A5, are described. These analogues were selected on the basis of Cl→CH3 or H3C→Cl exchanges in the side‐chain of atpenin A5. The interchange of chloro and methyl substituents led to complex II inhibitors with equal IC50 values. This suggests that Cl?Me bioisosteric exchange can be realized in aliphatic settings. 相似文献
992.
Nico Schwarze Dr. Simon Steinhauer Beate Neumann Dr. Hans‐Georg Stammler Prof. Dr. Berthold Hoge 《Angewandte Chemie (International ed. in English)》2016,55(52):16156-16160
Tris(pentafluoroethyl)silane, which is conveniently accessible by the treatment of Si(C2F5)3X (X=Cl, Br) with Bu3SnH, was successfully employed for hydrosilylation reactions. In the presence of a palladium catalyst, hydrosilylation of phenylacetylene with Si(C2F5)3H affords the product of an α‐addition whereas the reaction of trimethylsilylacetylene with the silane leads to the β‐trans product. Tris(pentafluoroethyl)silane can be deprotonated by sterically demanding bases such as lithium diisopropylamide at low temperatures to give the corresponding silanide ion. The addition of crown ethers or cryptands to this highly reactive species enabled the isolation and characterization of salt‐like tris(pentafluoroethyl)silanide at room temperature. 相似文献
993.
994.
995.
We study the isomorphism and bi-embeddability relations on the spaces of Kazhdan groups and finitely generated simple groups. 相似文献
996.
We prove that certain means of the quadratical partial sums of the two‐dimensional Vilenkin‐Fourier series are uniformly bounded operators from the Hardy space to the space for We also prove that the sequence in the denominator cannot be improved. 相似文献
997.
The use of 2H NMR spectroscopy as a tool for the analysis of enantiomeric purity is reported. Enantiopure isotopically chiral substrates bearing a monodeuterated methylene unit were prepared; introduction of an additional asymmetric center leads to diastereomers which can be distinguished by 2H NMR on a standard spectrometer. The assays allow for simple semiquantitative analysis of asymmetric transformations. 相似文献
998.
Polgar T Magyar C Simon I Keserü GM 《Journal of chemical information and modeling》2007,47(6):2366-2373
Structure-based virtual screens were carried out against beta-secretase (BACE1) to investigate the impact of ligand protonation on screening efficacy. A comparative evaluation of the performance and its dependence on ligand protonation states docking by Surflex, eHiTS, GOLD, and FlexX-Pharm was performed. Virtual screening performed by FlexX-Pharm (EF(1%)=69) and Surflex (EF(1%)=58) provided the best efficiency. Screening protocols by FlexX-Pharm and GOLD were affected by ligand protonation, while performance of Surflex did not depend on ligand protonation. 相似文献
999.
Grombe R Gouzy MF Maitz MF Freundenberg U Zschoche S Simon F Pompe T Sperling C Werner C 《Macromolecular bioscience》2007,7(2):195-200
The impact of heparinoid characteristics on model surfaces obtained from immobilization of sole sulfate groups as well as sulfated glycosides, sulfated cellulose, and definite heparin has been investigated. The obtained layers were physico-chemically characterized regarding film thickness, chemical composition, wettability, and surface morphology. Antithrombin adsorption, studied by fluorescence labeling, revealed a strong dependence on the presence of glycosidic structures and on the molecular weight of the grafted saccharide. On contact with whole blood, the coatings resulted in a diminished plasmatic and cellular coagulation in vitro, which did not reflect well the antithrombin binding. Therefore, more complex activating pathways are discussed. 相似文献
1000.