排序方式: 共有115条查询结果,搜索用时 296 毫秒
51.
52.
Costanza Vanni Anne Bodlenner Marco Marradi Jrmy P. Schneider Maria de los Angeles Ramirez Sergio Moya Andrea Goti Francesca Cardona Philippe Compain Camilla Matassini 《Molecules (Basel, Switzerland)》2021,26(19)
Among carbohydrate-processing enzymes, Jack bean α-mannosidase (JBα-man) is the glycosidase with the best responsiveness to the multivalent presentation of iminosugar inhitopes. We report, in this work, the preparation of water dispersible gold nanoparticles simultaneously coated with the iminosugar deoxynojirimycin (DNJ) inhitope and simple monosaccharides (β-d-gluco- or α-d-mannosides). The display of DNJ at the gold surface has been modulated (i) by using an amphiphilic linker longer than the aliphatic chain used for the monosaccharides and (ii) by presenting the inhitope, not only in monomeric form, but also in a trimeric fashion through combination of a dendron approach with glyconanotechnology. The latter strategy resulted in a strong enhancement of the inhibitory activity towards JBα-man, with a Ki in the nanomolar range (Ki = 84 nM), i.e., more than three orders of magnitude higher than the monovalent reference compound. 相似文献
53.
Benjamin Liet Dr. Eugénie Laigre Dr. David Goyard Biagio Todaro Claire Tiertant Dr. Didier Boturyn Dr. Nathalie Berthet Prof. Dr. Olivier Renaudet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(68):15508-15515
We have developed a fully synthetic and multifunctional antibody-recruiting molecule (ARM) to guide natural antibodies already present in the blood stream against cancer cells without pre-immunization. Our ARM is composed of antibody and tumor binding modules (i.e., ABM and TBM) displaying clustered rhamnose and cyclo-RGD, respectively. By using a stepwise approach, we have first demonstrated the importance of multivalency for efficient recognition with naturel IgM and αvβ3 integrin expressing M21 tumor cell line. Once covalently conjugated by click chemistry, we confirmed by flow cytometry and confocal microscopy that the recognition properties of both the ABM and TBM are conserved, and more importantly, that the resulting ARM promotes the formation of a ternary complex between natural IgM and cancer cells, which is required for the stimulation of the cytotoxic immune response in vivo. Due to the efficiency of the synthetic process, a larger diversity of heterovalent ligands could be easily explored by using the same multivalent approach and could open new perspectives in this field. 相似文献
54.
Rakesh Biswas Sumit Naskar Surya Ghosh Prof. Dr. Mousumi Das Prof. Dr. Supratim Banerjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(60):13595-13600
Signal transduction is essential for the survival of living organisms, because it allows them to respond to the changes in external environments. In artificial systems, signal transduction has been exploited for the highly sensitive detection of analytes. Herein, a remarkable signal transduction, upon ATP binding, in the multivalent fibrillar nanoaggregates of anthracene conjugated imidazolium receptors is reported. The aggregates of one particular amphiphilic receptor sensed ATP in high pm concentrations with one ATP molecule essentially quenching the emission of thousands of receptors. A cooperative merging of the multivalent binding and signal transduction led to this superquenching and translated to an outstanding enhancement of more than a millionfold in the sensitivity of ATP detection by the nanoaggregates; in comparison to the “molecular” imidazolium receptors. Furthermore, an exceptional selectivity to ATP over other nucleotides was demonstrated. 相似文献
55.
Dr. Arianna Pina Malika Kadri Dr. Daniela Arosio Dr. Alberto Dal Corso Dr. Jean-Luc Coll Prof. Dr. Cesare Gennari Dr. Didier Boturyn 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(33):7492-7496
The use of multimeric ligands is considered as a promising strategy to improve tumor targeting for diagnosis and therapy. Herein, tetrameric RGD (Arg-Gly-Asp) peptidomimetics were designed to target αvβ3 integrin-expressing tumor cells. These compounds were prepared by an oxime chemoselective assembly of cyclo(DKP-RGD) ligands and a cyclodecapeptide scaffold, which allows a tetrameric presentation. The resulting tetrameric RGD peptidomimetics were shown to improve αvβ3 integrin binding compared with the monomeric form. Interestingly, these compounds were also able to enhance tumor cell endocytosis in the same way as tetrameric RGD peptides. Altogether, the results show the potential of the tetrameric cyclo(DKP-RGD) ligands for in vivo imaging and drug delivery. 相似文献
56.
Taylor A. Neal Weikun Wang Dr. Lei Zhiquan Ruojing Peng Priti Soni Han Xie Prof. Jovica D. Badjić 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(5):1242-1248
Inspired by polyvalency and its prevalence in nature, we developed an efficient synthetic route for accessing a large variety of multivalent and dual-cavity baskets from inexpensive and abundant starting materials. First, the cycloaddition of vinyl acetate to anthracene was optimized to, upon hydrolysis, give dibenzobarrelene derivative 6 , which after five functional group transformations and then cyclotrimerization gave heptiptycene dodecaester 4 in an overall 17 % yield. Following that, compound 4 was converted into D3h symmetric 1 , composed of two fused cavitands each holding three terminal alkynes at the rim for conjugation to functional molecules using the highly efficient CuAAC reaction. To survey the reactivity of hexavalent 1 , we “clicked” 2-acetamido-2-deoxy-β-d -glucopyranosyl azide 3,4,6-triacetate (carbohydrate), methoxypolyethylene glycol azide (PEG, Mn=2000; polymer) and benzyl azide (aromatic) to obtain hexavalent conjugates 12 – 14 in 50–79 % yields. In summary, dual-cavity 1 is an accessible, structurally-unique and hexavalent host that can be “clicked” to a variety of functional molecules for (a) combinatorial lead identification of drugs, (b) preparation of hierarchical soft materials and (c) design of selective chemosensors, scavengers, or supramolecular catalysts. 相似文献
57.
Mechanistic Insight into Nanomolar Binding of Multivalent Neoglycopeptides to Wheat Germ Agglutinin
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Philipp Rohse Prof. Dr. Valentin Wittmann 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(28):9724-9733
Multivalent carbohydrate–protein interactions are frequently involved in essential biological recognition processes. Accordingly, multivalency is often also exploited for the design of high‐affinity lectin ligands aimed at the inhibition of such processes. In a previous study (D. Schwefel et al., J. Am. Chem. Soc. 2010 , 132, 8704–8719) we identified a tetravalent cyclopeptide‐based ligand with nanomolar affinity to the model lectin wheat germ agglutinin (WGA). To unravel the structural features of this ligand required for high‐affinity binding to WGA, we synthesized a series of cyclic and linear neoglycopeptides that differ in their conformational freedom as well as the number of GlcNAc residues. Combined evidence from isothermal titration calorimetry (ITC), enzyme‐linked lectin assays (ELLA), and dynamic light scattering (DLS) revealed different binding modes of tetra‐ and divalent ligands and that conformational preorganization of the ligands by cyclization is not a prerequisite for achieving high binding affinities. The high affinities of the tetravalent ligands rather stem from their ability to form crosslinks between several WGA molecules. The results illustrate that binding affinities and mechanisms are strongly dependent on the used multivalent system which offers opportunities to tune and control binding processes. 相似文献
58.
Cover Picture: Fluorescent Silica Nanoparticles with Multivalent Inhibitory Effects towards Carbonic Anhydrases (Chem. Eur. J. 29/2015)
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
59.
60.
Dr. Sven O. Krabbenborg Janneke Veerbeek Prof. Dr. Jurriaan Huskens 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(27):9638-9644
Self‐assembly to create molecular and nanostructures is typically performed at the thermodynamic minimum. To achieve dynamic functionalities, such as adaptability, internal feedback, and self‐replication, there is a growing focus on out‐of‐equilibrium systems. This report presents the dynamic self‐assembly of an artificial host–guest system at an interface, under control by a dissipative electrochemical process using (electrical) energy, resulting in an out‐of‐equilibrium system exhibiting a supramolecular surface gradient. The gradient, its steepness, rate of formation, and complex surface composition after backfilling, as well as the surface compositions after switching between the different states of the system, are assessed and supported by modelling. Our method shows for the first time an artificial surface‐confined out‐of‐equilibrium system. The electrochemical process parameters provide not only control over the system in time, but also in space. 相似文献