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排序方式: 共有662条查询结果,搜索用时 78 毫秒
31.
Benjamin D. Egleston Konstantin V. Luzyanin Michael C. Brand Rob Clowes Michael E. Briggs Rebecca L. Greenaway Andrew I. Cooper 《Angewandte Chemie (International ed. in English)》2020,59(19):7362-7366
Control of pore window size is the standard approach for tuning gas selectivity in porous solids. Here, we present the first example where this is translated into a molecular porous liquid formed from organic cage molecules. Reduction of the cage window size by chemical synthesis switches the selectivity from Xe‐selective to CH4‐selective, which is understood using 129Xe, 1H, and pulsed‐field gradient NMR spectroscopy. 相似文献
32.
The scalable, divergent synthesis of all four monomers required for the preparation of sulfonamide-based RNA mimetics is described. Such mimetics may combine excellent mimicry of the parent RNA with enhanced (bio)chemical robustness and convenient oligomerization. As a proof of principle, a dimer resulting from the monomers is described. 相似文献
33.
Rob G. Visser 《Accreditation and quality assurance》2016,21(3):237-238
The tentative arguments mentioned by Paul De Bievre are discussed and alternatives are given that may lead to different insights. 相似文献
34.
Linington RG Robertson M Gauthier A Finlay BB van Soest R Andersen RJ 《Organic letters》2002,4(23):4089-4092
Extracts of the marine sponge Caminus sphaeroconia showed potent activity in a screen for bacterial type III secretion inhibitors. Bioassay guided fractionation of the extract led to the isolation of the novel antimicrobial glycolipid caminoside A (1). The structure of caminoside A was elucidated by analysis of spectroscopic data and chemical degradation.[structure: see text] 相似文献
35.
Takada K Uehara T Nakao Y Matsunaga S van Soest RW Fusetani N 《Journal of the American Chemical Society》2004,126(1):187-193
Three new alpha-glucosidase inhibitors, schulzeines A-C (1-3), were isolated from the marine sponge Penares schulzei. Their structures were elucidated by spectral analysis and chemical degradations to be the isoquinoline alkaloids, encompassing two amino acids, and C(28) fatty acid, the last of which was sulfated. Absolute stereochemistry of schulzeines was determined by application of the modified Mosher analysis to fragments obtained by chemical degradation. Schulzeines A-C inhibit alpha-glucosidase with IC(50) values of 48-170 nM. 相似文献
36.
The sulfonamide moiety was introduced as a potential transition state isostere of the hydrolysis of the amide bond. Subsequently, the increased acidity of a sulfonamide N-H as compared to a regular amide N-H was explored in the development of peptidosulfonamide synthetic receptor molecules for binding and catalysis. The required building blocks for these compounds were accessible via an efficient synthesis, which also enabled the synthesis of oligopeptidosulfonamides as well as peptidosulfonamide-betapeptide hybrids. The structural consequences of the introduction of the peptidosulfonamide residues were studied and were further explored by the synthesis of cyclic peptidosulfonamides e.g. by ring-closing metathesis. 相似文献
37.
Nishimura S Matsunaga S Shibazaki M Suzuki K Furihata K van Soest RW Fusetani N 《Organic letters》2003,5(13):2255-2257
Massadine, a highly oxygenated alkaloid, was isolated from the marine sponge Stylissa aff. massa as an inhibitor of geranylgeranyltransferase type I (GGTase I). The structure of massadine has been deduced from spectral data. Massidine inhibited GGTase I from Candida albicans with an IC(50) value of 3.9 microM. [structure: see text] 相似文献
38.
M. Bandsept H. Rohrbeck Rob Meyer Wendt Peeschla F. Stolle Purrmann J. H. Büchler F. Allihn Schaller Alb Bruno F. Reiss und Rud Woy 《Fresenius' Journal of Analytical Chemistry》1903,42(4-5):314-318
Ohne Zusammenfassung 相似文献
39.
40.
Maik J. Geerken Max N.W. Groenendijk Rob G.H. Lammertink Matthias Wessling 《Journal of membrane science》2008,310(1-2):374-383
In this paper the fabrication and use of micro-structured metal nozzle plates as emulsification devices is investigated and discussed. These structured metal nozzle plates were fabricated via two distinct routes. Laser ablation, performed with a femtosecond laser, was used to drill micrometer-sized holes into stainless steel and aluminum foils. Also a conventional steel mesh with an average pore size of 2.4 μm fabricated by weaving and roll compaction of micrometer-sized steel wires was investigated. The perforated metal nozzle plates were used for oil-in-water and after hydrophobization with alkylchlorosilanes for water-in-oil emulsification as well. In both cases, two types of drop formation processes were observed. The first one is the shear-induced drop formation well known for cross-flow membrane emulsification. The second is the spontaneous drop formation known from microchannel emulsification. 相似文献