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21.
Ultramicroelectrode sensor arrays in which each electrode, or groups of electrodes, are individually addressable are of particular interest for detection of several species concomitantly, by using specific sensing chemistry for each analyte, or for mapping of one analyte to achieve spatio–temporal analysis. Microfabrication technology, for example photolitography, is usually used for fabrication of these arrays. The most widespread geometries produced by photolithography are thin-film microdisc electrode arrays with different electrode distributions (square, hexagonal, or random). In this paper we review different electrochemical sensor arrays developed to monitor, in vivo, NO levels produced by cultured cells or sliced tissues. Simultaneous detection of NO and analytes interacting with or released at the same time as NO is also discussed. 相似文献
22.
Qiuqin Zhou Florian Grundmann Marcel Kaiser Matthias Schiell Dr. Sophie Gaudriault Dr. Andreas Batzer Dr. Michael Kurz Prof. Dr. Helge B. Bode 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(49):16772-16779
During the search for novel natural products from entomopathogenic Xenorhabdus doucetiae DSM17909 and X. mauleonii DSM17908 novel peptides named xenoamicins were identified in addition to the already known antibiotics xenocoumacin and xenorhabdin. Xenoamicins are acylated tridecadepsipeptides consisting of mainly hydrophobic amino acids. The main derivative xenoamicin A ( 1 ) was isolated from X. mauleonii DSM17908, and its structure elucidated by detailed 1 D and 2 D NMR experiments. Detailed MS experiments, also in combination with labeling experiments, confirmed the determined structure and allowed structure elucidation of additional derivatives. Moreover, the xenoamicin biosynthesis gene cluster was identified and analyzed in X. doucetiae DSM17909, and its participation in xenoamicin biosynthesis was confirmed by mutagenesis. Advanced Marfey’s analysis of 1 showed that the absolute configuration of the amino acids is in agreement with the predicted stereochemistry deduced from the nonribosomal peptide synthetase XabABCD. Biological testing revealed activity of 1 against Plasmodium falciparum and other neglected tropical diseases but no antibacterial activity. 相似文献
23.
In the present work a modular pathway towards the synthesis of a new versatile MRI contrast agent is reported and its physico-chemical properties are described. Two different functional groups were attached on two arms of the gadolinium 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) in order to get a platform able to bind one probe designed to target specific biological marker and a fluorescent molecule likely to be used for optical imaging. The nuclear magnetic relaxation dispersion (NMRD) profile, the oxygen-17 relaxometric NMR study and stability assessment versus transmetalation of the Gd-complex show that this new contrast agent has a relaxivity and transmetalation stability similar to Gd–DOTA. 相似文献
24.
Leblond Sylvain Fichet Pascal Laumonier Rmi Billon Sophie Sardini Paul Colas Kimberly 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):1075-1089
Journal of Radioanalytical and Nuclear Chemistry - A new method has been developed to image surface contamination on-site by short range radiation emitters (such as alpha or beta particle... 相似文献
25.
Dr. Alberto Lena Dr. Alessandra Benassi Michele Stasi Christine Saint-Pierre Prof. Mauro Freccero Dr. Didier Gasparutto Dr. Sophie Bombard Prof. Filippo Doria Dr. Daniela Verga 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(35):e202200734
Combining the selectivity of G-quadruplex (G4) ligands with the spatial and temporal control of photochemistry is an emerging strategy to elucidate the biological relevance of these structures. In this work, we developed six novel V-shaped G4 ligands that can, upon irradiation, form stable covalent adducts with G4 structures via the reactive intermediate, quinone methide (QM). We thoroughly investigated the photochemical properties of the ligands and their ability to generate QMs. Subsequently, we analyzed their specificity for various topologies of G4 and discovered a preferential binding towards the human telomeric sequence. Finally, we tested the ligand ability to act as photochemical alkylating agents, identifying the covalent adducts with G4 structures. This work introduces a novel molecular tool in the chemical biology toolkit for G4s. 相似文献
26.
Ugo Authesserre Sophie Hameury Aymeric Dajnak Nathalie Saffon-Merceron Antoine Baceiredo David Madec Eddy Maerten 《Molecules (Basel, Switzerland)》2021,26(7)
Due to their remarkable electronic features, recent years have witnessed the emergence of carbones L2C, which consist in two donating L ligands coordinating a central carbon atom bearing two lone pairs. In this context, the phosphine/sulfoxide-supported carbone 4 exhibits a strong nucleophilic character, and here, we describe its ability to coordinate dichlorogermylene. Two original stable coordination complexes were obtained and fully characterized in solution and in the solid state by NMR spectroscopy and X-ray diffraction analysis, respectively. At 60 °C, in the presence of 4, the Ge(II)-complex 5 undergoes a slow isomerization that transforms the bis-ylide ligand into an yldiide. 相似文献
27.
Ivan Limachi Mariela Gonzalez-Ramirez Sophie Manner Juan C. Ticona Efrain Salamanca Alberto Gimenez Olov Sterner 《Molecules (Basel, Switzerland)》2021,26(4)
The fractionation of an ethanol extract of the bark of Trichilia adolfi yielded four novel limonoids (trichilinones A-D, 1–4), with five fused rings and related to the hortiolide-type limonoids. Starting with an ε-lactone, which is α,β-unsaturated in trichilinones A and D (1 and 4), attached to a tetrahydrofuran ring that is connected to an unusual bicyclo [5.1.0] hexane system, joined with a cyclopentanone with a 3-furanyl substituent [(2-oxo)-furan-(5H)-3-yl in trichilinone D (4)], the four compounds isolated display a new 7/5/3/5/5 limonoid ring system. Their structures were established based on extensive analysis of NMR spectroscopic data. As the crude extract possessed anti-leishmanial properties, the compounds were assayed for cytotoxic and anti-parasitic activities in vitro in murine macrophages cells (Raw 264.7) and leishmania promastigotes (L. amazoniensis and L. braziliensis), respectively. The compounds showed moderate cytotoxicity (approximately 70 μg/mL), but are not responsible for the leishmanicidal effect of the extract. 相似文献
28.
Max Kronenwerth Kenan A. J. Bozhüyük Dr. Astrid S. Kahnt Prof. Dr. Dieter Steinhilber Dr. Sophie Gaudriault Marcel Kaiser Prof. Dr. Helge B. Bode 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(52):17478-17487
Six new lipodepsipeptides and an additional linear derivative named taxlllaids A–G ( 1 – 7 ) have been identified in the entomopathogenic bacterium Xenorhabdus indica. The structures of the main compounds have been solved by detailed NMR spectroscopic analysis and the structures of minor derivatives were elucidated by a combination of labelling experiments and detailed MS experiments. The absolute configuration of the taxlllaids was deduced by using the advanced Marfey method and analysis of the biosynthesis gene cluster showing the presence of epimerisation domains, which was subsequently proved to be correct by solid‐phase peptide synthesis of all taxlllaids. The exchange of a single amino acid in the adenylation domain was shown to be responsible for substrate promiscuity of the third A domain, resulting in the incorporation of leucine, phenylalanine or tyrosine. Bioactivity testing revealed the taxlllaids to be weakly active against Plasmodium falciparum and against a number of eukaryotic cell lines. 相似文献
29.
Miriana Kfoury Lizette Auezova Sophie Fourmentin Hélène Greige-Gerges 《Journal of inclusion phenomena and macrocyclic chemistry》2014,80(1-2):51-60
In this study, we investigated the inclusion complexation of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and eight monoterpenes (eucalyptol, geraniol, limonene, linalool, α-pinene, β-pinene, pulegone, and thymol) in aqueous solution and solid state. The formation constants (K f) of inclusion complexes were determined using fluorescence spectroscopy and static headspace gas chromatography. The results indicated the formation of 1:1 inclusion complexes between HP-β-CD and all studied guests. A linear relationship was found between K f values and the hydrophobic character of the monoterpenes expressed as logP. Solid complexes were prepared by the freeze-drying method in a 1:1 (HP-β-CD:monoterpene) molar ratio. Physicochemical characterization of solid inclusion complexes was carried out using Fourier transform infrared spectroscopy and differential scanning calorimetry. Finally, the encapsulation efficiency (EE%) of HP-β-CD was determined using HPLC analysis. Noticeable difference in the EE% was observed between monoterpene hydrocarbons and oxygenated monoterpenes. These results suggested that complexation with HP-β-CD could be a promising strategy to enlarge the application of monoterpenes in cosmetic, pharmaceutical and food industries. 相似文献
30.
Dr. Viktor Pfeifer Marie Certiat Dr. Donia Bouzouita Dr. Alberto Palazzolo Sébastien Garcia-Argote Elodie Marcon David-Alexandre Buisson Dr. Philippe Lesot Prof. Laurent Maron Dr. Bruno Chaudret Dr. Simon Tricard Dr. Iker del Rosal Prof. Romuald Poteau Dr. Sophie Feuillastre Dr. Grégory Pieters 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):4988-4996
Ruthenium nanocatalysis can provide effective deuteration and tritiation of oxazole, imidazole, triazole and carbazole substructures in complex molecules using D2 or T2 gas as isotopic sources. Depending on the substructure considered, this approach does not only represent a significant step forward in practice, with notably higher isotope uptakes, a broader substrate scope and a higher solvent applicability compared to existing procedures, but also the unique way to label important heterocycles using hydrogen isotope exchange. In terms of applications, the high incorporation of deuterium atoms, allows the synthesis of internal standards for LC-MS quantification. Moreover, the efficacy of the catalyst permits, even under subatmospheric pressure of T2 gas, the preparation of complex radiolabeled drugs owning high molar activities. From a fundamental point of view, a detailed DFT-based mechanistic study identifying undisclosed key intermediates, allowed a deeper understanding of C−H (and N−H) activation processes occurring at the surface of metallic nanoclusters. 相似文献