排序方式: 共有124条查询结果,搜索用时 15 毫秒
61.
α,α-Difluorophosphonohydroxamic Acid Derivatives among the Best Antibacterial Fosmidomycin Analogues
Aurore Dreneau Fanny S. Krebs Mathilde Munier Chheng Ngov Denis Tritsch Didier Livremont Michel Rohmer Catherine Grosdemange-Billiard 《Molecules (Basel, Switzerland)》2021,26(16)
Three α,α-difluorophosphonate derivatives of fosmidomycin were synthesized from diethyl 1,1-difluorobut-3-enylphosphonate and were evaluated on Escherichia coli. Two of them are among the best 1-deoxy-d-xylulose 5-phosphate reductoisomerase inhibitors, with IC50 in the nM range, much better than fosmidomycin, the reference compound. They also showed an enhanced antimicrobial activity against E. coli on Petri dishes in comparison with the corresponding phosphates and the non-fluorinated phosphonate. 相似文献
62.
We report on the behavior of micron-sized prolate ellipsoids trapped at an oil-water interface. The particles experience strong, anisotropic, and long-ranged attractive capillary interactions which greatly exceed the thermal energy k(B)T. Depending on surface chemistry, the particles aggregate into open structures or chains. Using video microscopy, we extract the pair interaction potential between ellipsoids and show it exhibits a power law behavior over the length scales probed. Our observations can be explained using recent calculations, if we describe the interfacial ellipsoids as capillary quadrupoles. 相似文献
63.
CNDO/2 calculations were performed on cyclohexane, cyclohexyl fluoride and 1,1-difluorocyclohexane. The electronic structure is discussed and compared with experimental data. 相似文献
64.
Dr. Eduard Badarau Dr. K. Harsha Vardhan Reddy Dr. Aurore Loudet Dr. Charles Simon Dr. Laurent Trembleau Dr. Stijn Claerhout Dr. Etienne Pair Stéphane Massip Dr. Philippe Breton Dr. Brigitte Lesur Dr. Solo Goldstein Dr. Jean-Marie Fourquez Dr. Jean Michel Henlin Prof. Léon Ghosez 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15477-15481
Identification of a common Diels–Alder pattern in three classes of bioactive natural products led us to study the synthesis and cycloaddition of a new class of cyclic dienes readily available from β,γ-unsaturated lactams. A practical and readily scalable route to the parent p-methoxybenzyl-protected 6- and 7-membered β,γ-unsaturated lactams was developed. These were readily transformed into the corresponding O-silylated dienes, which were reacted with dimethyl and diethyl fumarate to yield stereoselectively highly functionalized bicyclic adducts. These exhibited unexpected and versatile transformations upon acid hydrolysis depending on the nature of the dienophile substituents and the acid catalyst. All reactions have been performed on multigram quantities. These transformations provide a convenient, economical, and easily scalable pathway for the rapid construction of functionally and stereochemically dense privileged scaffolds for the construction of libraries of natural products-inspired molecules of pharmacological relevance. 相似文献
65.
1H‐NMR relaxometric studies of interaction between apoptosis specific MRI paramagnetic contrast agents and micellar models of apoptotic cells 下载免费PDF全文
Aurore Van Koninckxloo Céline Henoumont Sophie Laurent Robert N. Muller Luce Vander Elst 《Magnetic resonance in chemistry : MRC》2016,54(7):568-574
1H‐NMR was previously used to analyze the interaction between peptides (E3 and R826) selected by phage display to target apoptotic cells and phospholipidic models of these cells. In order to avoid the use of apoptotic cells and to obtain a fast evaluation of the efficiency of the potential MRI contrast agents obtained by grafting these peptides and their scramble analogs on a paramagnetic gadolinium complex, their proton relaxometric behavior was investigated in the presence of micelles mimicking healthy and apoptotic cells. Their preferential interaction with 1,2‐dipalmitoyl‐sn‐glycero‐3‐phospho‐l ‐serine micelles mimicking apoptotic cells as compared with 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine micelles modeling healthy cells was shown by nuclear magnetic relaxation dispersion profiles and the enhancement of the transverse proton relaxation rates at 60 MHz. The association constant values confirm the stronger interaction of the selected conjugated peptides (Ka Gd‐PMN‐E3(gadolinium 2,2′,2′′,2′′′‐[((4‐carboxy)pyridine‐2,6‐diyl)bis(methylenenitrilo)]‐tetrakis acetate) grafted with E3 peptide): 2.43 104 m ?1; Ka Gd‐DTPA‐R826(gadolinium ((1‐p‐isothiocyanatobenzyl)‐diethylenetriaminepentaacetate) grafted with R826 peptide): 2.91 104 m ?1) as compared with their conjugated scrambles (Ka Gd‐PMN‐E3sc(gadolinium 2,2′,2′′,2′′′‐[((4‐carboxy)pyridine‐2,6‐diyl)bis(methylenenitrilo)]‐tetrakis acetate) grafted with E3 scramble peptide): 0.18 104 m ?1; Ka Gd‐DTPA‐R826sc(gadolinium ((1‐p‐isothiocyanatobenzyl)‐diethylenetriaminepentaacetate) grafted with R826 scramble peptide): 0.32 104 m ?1) even if the conjugation of E3 and R826 seems to decrease their interaction. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
66.
Olivier C Perzyna A Coffinier Y Grandidier B Stiévenard D Melnyk O Durand JO 《Langmuir : the ACS journal of surfaces and colloids》2006,22(16):7059-7065
While fluorescent-based methods are generally used to detect the immobilization and the interactions of biomolecules to solid supports, recent studies have shown their limitations in the case of silicon surfaces. As an alternative, we investigated the synthesis of peptides labeled with a metal transition complex and their subsequent immobilization to the silicon surfaces. The feasibility of using such probes has been explored by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). By starting with hydrogen-terminated or oxidized silicon surfaces, we functionalized those surfaces with semicarbazide groups and showed the site-specific linkage of glyoxylyl peptides labeled with a Co2(CO)6 moiety. 相似文献
67.
Schneider A Francius G Obeid R Schwinté P Hemmerlé J Frisch B Schaaf P Voegel JC Senger B Picart C 《Langmuir : the ACS journal of surfaces and colloids》2006,22(3):1193-1200
Mechanical properties of model and natural gels have recently been demonstrated to play an important role in various cellular processes such as adhesion, proliferation, and differentiation, besides events triggered by chemical ligands. Understanding the biomaterial/cell interface is particularly important in many tissue engineering applications and in implant surgery. One of the final goals would be to control cellular processes precisely at the biomaterial surface and to guide tissue regeneration. In this work, we investigate the substrate mechanical effect on cell adhesion for thin polyelectrolyte multilayer (PEM) films, which can be easily deposited on any type of material. The films were cross linked by means of a water-soluble carbodiimide (EDC), and the film elastic modulus was determined using the AFM nanoindentation technique with a colloidal probe. The Young's modulus could be varied over 2 orders of magnitude (from 3 to 400 kPa) for wet poly(L-lysine)/hyaluronan (PLL/HA) films by changing the EDC concentration. The chemical changes upon cross linking were characterized by means of Fourier transform infrared spectroscopy (FTIR). We demonstrated that the adhesion and spreading of human chondrosarcoma cells directly depend on the Young's modulus. These data indicate that, besides the chemical properties of the polyelectrolytes, the substrate mechanics of PEM films is an important parameter influencing cell adhesion and that PEM offer a new way to prepare thin films of tunable mechanical properties with large potential biomedical applications including drug release. 相似文献
68.
Kim TG Castro JC Loudet A Jiao JG Hochstrasser RM Burgess K Topp MR 《The journal of physical chemistry. A》2006,110(1):20-27
Fluorescent DNA-labeling cassettes are designed to have a common absorbing chromophore matched to a single exciting laser wavelength, but up to four different emitters. Experiments reported here have examined the energy-transfer rates and fluorescence polarization characteristics for two different types of cassette, involving three distinct relative orientations of the donor and acceptor transition moments and the axis of the rigid linker. Energy-transfer times range from <200 fs to approximately 20 ps, the fastest transfer times occurring when the transition moments of the donor and acceptor species are aligned parallel to the linker axis. Experimental evidence is presented that supports a through-bond energy-transfer mechanism, in contrast with a commercial DNA-labeling agent, which exhibits much slower transfer times controlled by FRET. These rigid cassettes also exhibit polarized fluorescence from the acceptor species, so that this particular type of DNA-labeling probe has some of the advantages of single-molecule probes such as rhodamine and coumarin dyes. 相似文献
69.
Dr. Aurore De Rache Nassima Meriem Gueddouda Dr. Anne Bourdoncle Dr. Paul Hommes Prof. Dr. Hans‐Ulrich Reissig Dr. Jean‐Louis Mergny 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(36):12651-12654
G‐quadruplexes formed by nucleic acids are implicated in pathologies ranging from cancers to neurodegenerative diseases. We evaluated interactions of 29 bi‐ and terpyridine derivatives with G‐quadruplexes and duplexes. FRET‐melting, circular dichroism, and 1H NMR spectroscopy showed that one terpyridine derivative interacted very selectively with G‐quadruplexes. This G‐quadruplex ligand inhibited helicase activity and should influence G‐quadruplex‐related biological processes. 相似文献