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Click chemistry

Diego G Ghiano, Agustina de la Iglesia, Nina Liu, Peter J Tonge, Héctor R Morbidoni, Guillermo R Labadie
A collection of 1,2,3-triazoles unsaturated fatty acid mimics were efficiently synthesized by click chemistry. The 1,4-disubstituted analogs prepared covered different alkyl chain lengths and triazole positions. The compounds were subsequently tested against Mycobacterium tuberculosis, being most of them active with some of the analogs displaying activity at micromolar concentration. The most potent member of the series has the triazole moiety on the C-2 position with a carbon chain of eight or ten carbon atoms...
September 28, 2016: European Journal of Medicinal Chemistry
Christine Koehler, Paul F Sauter, Mirella Wawryszyn, Gemma Estrada Girona, Kapil Gupta, Jonathan J M Landry, Markus Hsi-Yang Fritz, Ksenija Radic, Jan-Erik Hoffmann, Zhuo A Chen, Juan Zou, Piau Siong Tan, Bence Galik, Sini Junttila, Peggy Stolt-Bergner, Giancarlo Pruneri, Attila Gyenesei, Carsten Schultz, Moritz Bosse Biskup, Hueseyin Besir, Vladimir Benes, Juri Rappsilber, Martin Jechlinger, Jan O Korbel, Imre Berger, Stefan Braese, Edward A Lemke
We present a baculovirus-based protein engineering method that enables site-specific introduction of unique functionalities in a eukaryotic protein complex recombinantly produced in insect cells. We demonstrate the versatility of this efficient and robust protein production platform, 'MultiBacTAG', (i) for the fluorescent labeling of target proteins and biologics using click chemistries, (ii) for glycoengineering of antibodies, and (iii) for structure-function studies of novel eukaryotic complexes using single-molecule Förster resonance energy transfer as well as site-specific crosslinking strategies...
October 17, 2016: Nature Methods
Sudath Hapuarachchige, Dmitri Artemov
Click chemistry provides fast, convenient, versatile, and reliable chemical reactions that take place between pairs of functional groups of small molecules that can be purified without chromatographic methods. Due to the fast kinetics and low or no elimination of byproducts, click chemistry is a promising approach that is rapidly gaining acceptance in drug discovery, radiochemistry, bioconjugation, and nanoscience applications. Increasing use of click chemistry in synthetic procedures or as a bioconjugation technique in diagnostic imaging is occurring because click reactions are fast, provide a quantitative yield, and produce a minimal amount of nontoxic byproducts...
October 2016: Topics in Magnetic Resonance Imaging: TMRI
Steven Silverman, John Moses, K Barry Sharpless
Vancomycin has long been considered a drug of last resort. Its efficiency in treating multiple drug-resistant bacterial infections, particularly methicillin resistant S. aureus (MRSA), has had a profound effect on the treatment of life-threatening infections. However, the emergence of resistance to vancomycin is a cause for significant world-wide concern, prompting the urgent development of new effective treatments for antibiotic resistant bacterial infections. Harnessing the benefits of multivalency and cooperativity against vancomycin-resistant strains, we report a Click Chemistry approach towards reengineered vancomycin derivatives and the synthesis of a number of dimers with increased potency against MRSA and vancomycin resistant Enterococci (VRE)...
October 16, 2016: Chemistry: a European Journal
James R Wright, James D Crowley, Nigel T Lucas
Hexaphenylbenzene (HPB) and hexa-peri-hexabenzocoronene-(HBC) functionalised 1,2,3-triazoles have been synthesised using an optimised copper(i)-catalysed azide-alkyne cycloaddition (CuAAC) reaction. The coordination chemistry of these ligands was explored through the synthesis of the respective palladium(ii) complexes and their activity as catalysts in the Suzuki-Miyaura reaction assessed.
October 17, 2016: Chemical Communications: Chem Comm
Siddiq Pasha Shaik, V Lakshma Nayak, Faria Sultana, A V Subba Rao, Anver Basha Shaik, Korrapati Suresh Babu, Ahmed Kamal
A series of imidazo[2,1-b]thiazole linked triazole conjugates were synthesized by using Huisgen 1,3-dipolar cyclo-addition reaction (click chemistry approach) and evaluated for their antiproliferative activity against some human cancer cell lines like, HeLa (cervical), DU-145 (prostate), A549 (lung), MCF-7 (breast) and HepG2 (liver). Among them, Conjugates 4g and 4h demonstrated a significant antiproliferative effect against human lung cancer cells (A549) with IC50 values of 0.92 and 0.78 μM respectively...
September 20, 2016: European Journal of Medicinal Chemistry
Luis M De Leon-Rodriguez, Yacine Hemar, Guang Mo, Alok K Mitra, Jillian Cornish, Margaret A Brimble
We report the synthesis and characterization of multifunctional peptides comprised of a hydrogel forming β-sheet peptide segment and a matrix metalloproteinase 2 substrate containing a propargylglycinyl linker that is further derivatized with a RGD peptide sequence via "click" chemistry. In contrast to currently known systems, these multifunctional peptides formed gels that are stiffer than those formed by their respective precursors. All the peptides showed reversible thermoresponsive properties, which render them as suitable lead systems for a variety of possible biomedical applications...
October 12, 2016: Acta Biomaterialia
Lei Wu, Ulrich Glebe, Alexander Böker
Binary polystyrene and poly(4-vinylpyridine) mixed grafted silica nanoparticles (PSt/P4VP-g-SNPs) are fabricated using Cu(I) -catalyzed azide-alkyne Huisgen cycloaddition (CuAAC) via grafting-to method. Azide-terminated PSt and P4VP are synthesized via post- and pre-atom transfer radical polymerization modification, respectively. Then, the polymers are simultaneously anchored onto alkyne-modified SNPs by CuAAC yielding mixed brushes as shown by Raman spectroscopy, dynamic light scattering, and thermogravimetric analysis...
October 13, 2016: Macromolecular Rapid Communications
Jorin Hoogenboom, Nathalja Berghuis, Dario Cramer, Rene Geurts, Han Zuilhof, Tom Wennekes
BACKGROUND: Carbohydrates, also called glycans, play a crucial but not fully understood role in plant health and development. The non-template driven formation of glycans makes it impossible to image them in vivo with genetically encoded fluorescent tags and related molecular biology approaches. A solution to this problem is the use of tailor-made glycan analogs that are metabolically incorporated by the plant into its glycans. These metabolically incorporated probes can be visualized, but techniques documented so far use toxic copper-catalyzed labeling...
October 10, 2016: BMC Plant Biology
Shan Yu, Ying Gao, Xu Mei, Tanchen Ren, Su Liang, Zhengwei Mao, Changyou Gao
The selective adhesion and migration of endothelial cells (ECs) over smooth muscle cells (SMCs) is very important in the rapid endothelialization of blood-contacting implants, to prevent vascular restenosis. In this study, a uniform cell-resistant layer of methacrylate-functionalized hyaluronic acid (HA) was first immobilized on a poly(ε-caprolactone) (PCL) film via polydopamine coupling. Then, a density gradient of thiol-functionalized Arg-Glu-Asp-Val (REDV) peptide was prepared on the HA layer via thiol-ene click chemistry and the continuous injection method...
October 10, 2016: ACS Applied Materials & Interfaces
Xiaowen Yan, Jinhua Li, Qingqing Liu, Hanyong Peng, Aleksandra Popowich, Zhixin Wang, Xing-Fang Li, X Chris Le
Identification of arsenic-binding proteins is important for understanding arsenic health effects and for developing arsenic-based therapeutics. We report here a strategy for the capture and identification of arsenic-binding proteins in living cells. We designed an azide-labeled arsenical, p-azidophenylarsenoxide (PAzPAO), to serve bio-orthogonal functions: the trivalent arsenical group binds to cellular proteins in situ, and the azide group facilitates click chemistry with dibenzylcyclooctyne. The selective and efficient capture of arsenic-binding proteins enables subsequent enrichment and identification by shotgun proteomics...
October 10, 2016: Angewandte Chemie
Hua-Li Qin, Qinheng Zheng, Grant A L Bare, Peng Wu, K Barry Sharpless
A Heck-Matsuda process for the synthesis of the otherwise difficult to access compounds, β-arylethenesulfonyl fluorides, is described. Ethenesulfonyl fluoride (i.e., vinylsulfonyl fluoride, or ESF) undergoes β-arylation with stable and readily prepared arenediazonium tetrafluoroborates in the presence of the catalyst palladium(II) acetate to afford the E-isomer sulfonyl analogues of cinnamoyl fluoride in 43-97 % yield. The β-arylethenesulfonyl fluorides are found to be selectively addressable bis-electrophiles for sulfur(VI) fluoride exchange (SuFEx) click chemistry, in which either the alkenyl moiety or the sulfonyl fluoride group can be the exclusive site of nucleophilic attack under defined conditions, making these rather simple cores attractive for covalent drug discovery...
October 10, 2016: Angewandte Chemie
Qianjin Li, Tripta Kamra, Lei Ye
Combining straightforward molecular imprinting with orthogonal click chemistry and accessible fluorescent dyes, a modular approach has been developed to assemble turn-on optical sensors based on fluorescence resonance energy transfer in molecularly imprinted nanoparticles.
October 6, 2016: Chemical Communications: Chem Comm
Ting Cao, Ji Nie, Liang-Yuan Cai, Xiao-Hui Zhang, De-Wen Zhang, Ying-Lin Zhou, Xin-Xiang Zhang
Based on click chemistry and DNAzyme, we constructed for the first time a cupric ion triggered DNA diode using a tandem linkage-cleavage process, which could occur in order in a programmable and autonomous manner. This DNA diode is a new DNA functional element and can precisely control the translation direction of information.
October 13, 2016: Chemical Communications: Chem Comm
Mark D Vaughan, Zhengding Su, Elisabeth Daub, J F Honek
Bioincorporation of the methionine analogue S-(2-fluoroethyl)-l-homocysteine (l-MFE) into bacteriophage lysozyme overproduced in Escherichia coli results not only in the expected l-MFE incorporation but surprisingly substantial l-vinthionine incorporation into the labeled lysozymes. Synthetic l-vinthionine itself however is not activated by purified Escherichia coli methionyl-tRNA synthetase. The indirect preparation of vinthionine-containing proteins has the potential to be an alternate strategy to prepare vinyl thioether moieties for click chemistry applications on proteins...
September 26, 2016: Organic & Biomolecular Chemistry
N-H Nguyen, N Bogliotti, R Chennoufi, E Henry, P Tauc, E Salas, L J Roman, A Slama-Schwok, E Deprez, J Xie
A new series of photoactivable NADPH mimics bearing one or two O-carboxymethyl groups on the adenosine moiety have been readily synthesized using click chemistry. These compounds display interesting one- or two-photon absorption properties. Their fluorescence emission wavelength and quantum yields (Φ) are dependent on the solvent polarity, with a red-shift in a more polar environment (λmax,em = 460-467 nm, Φ > 0.53 in DMSO, and λmax,em = 475-491 nm, Φ < 0.17 in Tris). These compounds show good binding affinity towards the constitutive nNOS and eNOS, confirming for the first time that the carboxymethyl group can be used as a surrogate of phosphate...
October 12, 2016: Organic & Biomolecular Chemistry
Sibaprasad Maity, Ekaterina Viazovkina, Alexander Gall, Yuri Lyubchenko
Probing of biomolecular complexes by single-molecule force spectroscopy (SMFS) methods including AFM requires proper and suitable coupling methods for immobilization of biomolecules onto the AFM tip and the surface. The use of flexible tethers for the coupling process has dual advantages. First, they allow the specific immobilization of interacting molecules, and second, their flexibility facilitates the proper orientation of the interacting partners. Recently, we developed an approach termed Flexible Nano Array (FNA) in which interacting partners are located on the same polymeric FNA molecule separated by a flexible segment with a defined length...
2016: Journal of Nature and Science
J Delavoipière, Y Tran, E Verneuil, A Chateauminois
We report on the poroelastic indentation response of hydrogel thin films geometrically confined within contacts with rigid spherical probes of radii in the millimeter range. Poly(PEGMA) (poly(ethylene glycol) methyl ether methacrylate), poly(DMA) (dimethylacrylamide) and poly(NIPAM) (N-isopropylacrylamide) gel films with thickness less than 15 μm were grafted onto glass substrates using a thiol-ene click chemistry route. Changes in the indentation depth under constant applied load were monitored over time as a function of the film thickness and the radius of curvature of the probe using an interferometric method...
September 28, 2016: Soft Matter
Q Fu, K Xie, S Tan, J M Ren, Q Zhao, P A Webley, G G Qiao
A reduced copper metal-organic framework (rCu-MOF) containing Cu(I) ions was prepared by reducing raw MOFs (Cu-BTC). A series of polymer functionalizations and coupling reactions could subsequently be achieved via CuAAC click chemistry, thus demonstrating the high activity, facile recyclability and good structural stability of rCu-MOFs for catalytic applications.
October 6, 2016: Chemical Communications: Chem Comm
Fang Wei, Weiguo Wang, Yudao Ma, Chen-Ho Tung, Zhenghu Xu
Copper(i)-catalyzed azide-alkyne cycloaddition (CuAAC) is an essential "click chemistry" reaction that is widely used in chemical biology, medicinal chemistry and materials science. The CuAAC reaction of terminal alkynes provides a mild and efficient synthesis of 1,4-disubstituted 1,2,3-triazoles. However, the click reaction of internal alkynes with azides, giving trisubstituted triazoles, is very challenging. This feature article highlights the recent progress addressing this fundamental problem. Particular emphasis is on the current and emerging strategies to introduce functional groups to the C-5 position of triazoles in a regioselective manner...
October 3, 2016: Chemical Communications: Chem Comm
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