共查询到20条相似文献,搜索用时 15 毫秒
1.
Inside Back Cover: Clickable 5′‐γ‐Ferrocenyl Adenosine Triphosphate Bioconjugates in Kinase‐Catalyzed Phosphorylations (Chem. Eur. J. 13/2015) 下载免费PDF全文
Dr. Nan Wang Dr. Zhe She Yen‐Chun Lin Prof. Sanela Martić Dr. David J. Mann Prof. Heinz‐Bernhard Kraatz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(13):5255-5255
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Kuntrapakam Hema Kana M. Sureshan 《Angewandte Chemie (International ed. in English)》2020,59(23):8854-8859
Protein‐mimics are of great interest for their structure, stability, and properties. We are interested in the synthesis of protein‐mimics containing triazole linkages as peptide‐bond surrogate by topochemical azide‐alkyne cycloaddition (TAAC) polymerization of azide‐ and alkyne‐modified peptides. The rationally designed dipeptide N3‐CH2CO‐Phe‐NHCH2CCH ( 1 ) crystallized in a parallel β‐sheet arrangement and are head‐to‐tail aligned in a direction perpendicular to the β‐sheet‐direction. Upon heating, crystals of 1 underwent single‐crystal‐to‐single‐crystal polymerization forming a triazole‐linked pseudoprotein with Gly‐Phe‐Gly repeats. During TAAC polymerization, the pseudoprotein evolved as helical chains. These helical chains are laterally assembled by backbone hydrogen bonding in a direction perpendicular to the helical axis to form helical sheets. This interesting helical‐sheet orientation in the crystal resembles the cross‐α‐amyloids, where α‐helices are arranged laterally as sheets. 相似文献
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Omuralide and Vibralactone: Differences in the Proteasome‐ β‐Lactone‐γ‐Lactam Binding Scaffold Alter Target Preferences 下载免费PDF全文
Dr. Nerea Gallastegui Marion Rusch Dr. Christian Hedberg Prof. Dr. Stephan A. Sieber Prof. Dr. Michael Groll 《Angewandte Chemie (International ed. in English)》2014,53(2):571-574
Despite their structural similarity, the natural products omuralide and vibralactone have different biological targets. While omuralide blocks the chymotryptic activity of the proteasome with an IC50 value of 47 nM, vibralactone does not have any effect at this protease up to a concentration of 1 mM . Activity‐based protein profiling in HeLa cells revealed that the major targets of vibralactone are APT1 and APT2. 相似文献
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Jérémy Camponovo Jaime Ruiz Prof. Dr. Eric Cloutet Dr. Didier Astruc Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(12):2990-3002
Dendrimers for ion sensing : The synthesis and use of new tris‐alkynyl dendrons are reported. So‐called “click” reactions of the dendrimers described with azidomethylferrocene give 27‐ferrocenyl, 81‐ferrocenyl, and 243‐ferrocenyl dendrimers. Electrochemical recognition of oxo‐anions and Pd2+ cations has been compared using the three polyferrocenyl dendrimers.
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Prakash S. Sane Bhausaheb V. Tawade Indravadan Parmar Savita Kumari Samadhan Nagane Prakash P. Wadgaonkar 《Journal of polymer science. Part A, Polymer chemistry》2013,51(9):2091-2103
Two new initiators, namely, 4‐(4‐(2‐(4‐(allyloxy) phenyl)‐5‐hydroxypentane 2‐yl) phenoxy)benzaldehyde and 4‐(4‐(allyloxy) phenyl)‐4‐(4‐(4‐formylphenoxy) phenyl) pentyl 2‐bromo‐2‐methyl propanoate containing “clickable” hetero‐functionalities namely aldehyde and allyloxy were synthesized starting from commercially available 4,4′‐bis(4‐hydroxyphenyl) pentanoic acid. These initiators were utilized, respectively, for ring opening polymerization of ε‐caprolactone and atom transfer radical polymerization of methyl methacrylate. Well‐defined α‐aldehyde, α′‐allyloxy heterobifunctionalized poly(ε‐caprolactones) (Mn,GPC: 5900–29,000, PDI: 1.26–1.43) and poly(methyl methacrylate)s (Mn,GPC: 5300–28800, PDI: 1.19–1.25) were synthesized. The kinetic study of methyl methacrylate polymerization demonstrated controlled polymerization behavior. The presence of aldehyde and allyloxy functionality on polymers was confirmed by 1H NMR spectroscopy. Aldehyde‐aminooxy and thiol‐ene metal‐free double click strategy was used to demonstrate reactivity of functional groups on polymers. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
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Sarah El Habnouni Sébastien Blanquer Vincent Darcos Jean Coudane 《Journal of polymer science. Part A, Polymer chemistry》2009,47(22):6104-6115
A novel method is proposed to access to new poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) using poly(α‐iodo‐ε‐caprolactone‐co‐ε‐caprolactone) as polymeric substrate. First, ring‐opening (co)polymerizations of α‐iodo‐ε‐caprolactone (αIεCL) with ε‐caprolactone (εCL) are performed using tin 2‐ethylhexanoate (Sn(Oct)2) as catalyst. (Co)polymers are fully characterized by 1H NMR, 13C NMR, FTIR, SEC, DSC, and TGA. Then, these iodinated polyesters are used as polymeric substrates to access to poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) by two different strategies. The first one is the reaction of poly(αIεCL‐co‐εCL) with ammonia, the second one is the reduction of poly(αN3εCL‐co‐εCL) by hydrogenolysis. This poly(α‐amino‐ε‐caprolactone‐co‐ε‐caprolactone) (FαNH2εCL < 0.1) opens the way to new cationic and water‐soluble PCL‐based degradable polyesters. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6104–6115, 2009 相似文献
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Inhibition of Cu‐Amyloid‐β by using Bifunctional Peptides with β‐Sheet Breaker and Chelator Moieties
Madeleine Jensen Anne Canning Sabri Chiha Pierre Bouquerel Dr. Jeppe Trudslev Pedersen Prof. Dr. Jesper Østergaard Dr. Olivier Cuvillier Isabelle Sasaki Dr. Christelle Hureau Prof. Dr. Peter Faller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(16):4836-4839
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Efficient Atropodiastereoselective Access to 5,5′‐Bis‐1,2,3‐triazoles: Studies on 1‐Glucosylated 5‐Halogeno 1,2,3‐Triazoles and Their 5‐Substituted Derivatives as Glycogen Phosphorylase Inhibitors 下载免费PDF全文
David Goyard Aikaterini S. Chajistamatiou Anastasia I. Sotiropoulou Dr. Evangelia D. Chrysina Dr. Jean‐Pierre Praly Dr. Sébastien Vidal 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(18):5423-5432
Whereas copper‐catalyzed azide–alkyne cycloaddition (CuAAC) between acetylated β‐D ‐glucosyl azide and alkyl or phenyl acetylenes led to the corresponding 4‐substituted 1‐glucosyl‐1,2,3‐triazoles in good yields, use of similar conditions but with 2 equiv CuI or CuBr led to the 5‐halogeno analogues (>71 %). In contrast, with 2 equiv CuCl and either propargyl acetate or phenyl acetylene, the major products (>56 %) displayed two 5,5′‐linked triazole rings resulting from homocoupling of the 1‐glucosyl‐4‐substituted 1,2,3‐triazoles. The 4‐phenyl substituted compounds (acetylated, O‐unprotected) and the acetylated 4‐acetoxymethyl derivative existed in solution as a single form (d.r.>95:5), as shown by NMR spectroscopic analysis. The two 4‐phenyl substituted structures were unambiguously identified for the first time by X‐ray diffraction analysis, as atropisomers with aR stereochemistry. This represents one of the first efficient and highly atropodiastereoselective approaches to glucose‐based bis‐triazoles as single atropisomers. The products were purified by standard silica gel chromatography. Through Sonogashira or Suzuki cross‐couplings, the 1‐glucosyl‐5‐halogeno‐1,2,3‐triazoles were efficiently converted into a library of 1,2,3‐triazoles of the 1‐glucosyl‐5‐substituted (alkynyl, aryl) type. Attempts to achieve Heck coupling to methyl acrylate failed, but a stable palladium‐associated triazole was isolated and analyzed by 1H NMR and MS. O‐Unprotected derivatives were tested as inhibitors of glycogen phosphorylase. The modest inhibition activities measured showed that 4,5‐disubstituted 1‐glucosyl‐1,2,3‐triazoles bind weakly to the enzyme. This suggests that such ligands do not fit the catalytic site or any other binding site of the enzyme. 相似文献
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Dr. Matthias Stoop Dr. Geeta Meher Dr. Phaneendrasai Karri Prof. Dr. Ramanarayanan Krishnamurthy 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(45):15336-15345
Under potentially prebiotic scenarios, ribose (pentose), the component of RNA is formed in meager amounts, as opposed to ribulose and xylulose (pentuloses). Consequently, replacement of ribose in RNA, with pentulose sugars, gives rise to prospective oligonucleotide candidates that are potentially prebiotic structural variants of RNA that could be formed by the same type of chemical pathways that gave rise to RNA from ribose. The potentially natural alternative (1′→3′)‐ribulo oligonucleotides and (4′→3′)‐ and (1′→3′)‐xylulo oligonucleotides consisting of adenine and thymine were synthesized and found to exhibit no self‐pairing or cross‐pairing with RNA. This signifies that even though pentulose sugars may have been abundant in a prebiotic scenario, the pentulose nucleic acids (NAs), if and when formed, would not have been competitors of RNA, or interfered with the emergence of RNA as a functional informational system. The reason for the lack of base pairing in pentulose NA highlights the contrasting and central role played by the furanosyl ring in RNA and pentulose NA, enabling and optimizing the base pairing in RNA, while impeding it in pentulose NA. 相似文献
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Licheng Tan Samarendra Maji Claudia Mattheis Yiwang Chen Seema Agarwal 《Macromolecular bioscience》2012,12(12):1721-1730
Novel degradable and antibacterial polycaprolactone‐based polymers are reported in this work. The polyesters with pendent propargyl groups are successfully prepared by ring‐opening polymerization and subsequently used to graft antibacterial hydantoin moieties via click chemistry by a copper(I)‐catalyzed azide‐alkyne cycloaddition reaction. The well‐controlled chemical structures of the grafted copolymers and its precursors are verified by FT‐IR spectroscopy, NMR spectroscopy, and GPC characterizations. According to the DSC and XRD results, the polymorphisms of these grafted copolymers are mostly changed from semicrystalline to amorphous depending on the amount of grafted hydantoin. Antibacterial assays are carried out with Bacillus subtilis and two strains of Escherichia coli and show fast antibacterial action.
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Xiao‐Ding Xu Chang‐Sheng Chen Bo Lu Zong‐Chun Wang Si‐Xue Cheng Xian‐Zheng Zhang Ren‐Xi Zhuo 《Macromolecular rapid communications》2009,30(3):157-164
Two kinds of representative polymers, poly(N‐isopropylacrylamide) (PNIPAAm) and β‐cyclodextrin (β‐CD) were selected and modified with azide and alkyne fucntional groups, respectively. When the solutions of these two modified polymers were mixed together, a cross‐linking reaction, a type of Huisgen's 1,3‐dipolar azide‐alkyne cycloaddition, occurred in the presence of Cu(I) catalyst. The strategy described here provides several advantages for the hydrogel formation including mild reaction conditions and controllable gelation rate. The resulted hydrogels were studied in terms of scanning electric microscopy (SEM), equilibrium swelling ratio and swelling/shrinking kinetics. The data obtained demonstrated the hydrogels had a porous structure as well as favorable thermosensitivity.
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Bobby Happ Christian Friebe Andreas Winter Dr. Martin D. Hager Dr. Richard Hoogenboom Dr. Ulrich S. Schubert Prof. Dr. 《化学:亚洲杂志》2009,4(1):154-163
The synthesis of a variety of 2‐(1H‐1,2,3‐triazol‐4‐yl)‐pyridines by click chemistry is demonstrated to provide straightforward access to mono‐functionalized ligands. The ring‐opening polymerization of ε‐caprolactone initiated by such a mono‐functionalized ligand highlights the synthetic potential of this class of bidentate ligands with respect to polymer chemistry or the attachment onto surfaces and nanoparticles. The coordination to RuII ions results in homoleptic and heteroleptic complexes with the resultant photophysical and electrochemical properties strongly dependent on the number of these ligands attached to the RuII core. 相似文献
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Integrative Chemical Biology Approaches for Identification and Characterization of “Erasers” for Fatty‐Acid‐Acylated Lysine Residues within Proteins 下载免费PDF全文
Zheng Liu Tangpo Yang Xin Li Tao Peng Prof. Howard C. Hang Prof. Xiang David Li 《Angewandte Chemie (International ed. in English)》2015,54(4):1149-1152
Acylation of proteins with fatty acids is important for the regulation of membrane association, trafficking, subcellular localization, and activity of many cellular proteins. While significant progress has been made in our understanding of the two major forms of protein acylation with fatty acids, N‐myristoylation and S‐palmitoylation, studies of the acylation of lysine residues, within proteins, with fatty acids have lagged behind. Demonstrated here is the use of integrative chemical biology approaches to examine human sirtuins as de‐fatty‐acid acylases in vitro and in cells. Photo‐crosslinking chemistry is used to investigate enzymes which recognize fatty‐acid acylated lysine. Human Sirt2 was identified as a robust lysine de‐fatty‐acid acylase in vitro. The results also show that Sirt2 can regulate the acylation of lysine residues, of proteins, with fatty acids within cells. 相似文献
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Anion Recognition and Induced Self‐Assembly of an α,γ‐Cyclic Peptide To Form Spherical Clusters 下载免费PDF全文
Nuria Rodríguez‐Vázquez Dr. Manuel Amorín Dr. Ignacio Alfonso Prof. Dr. Juan R. Granja 《Angewandte Chemie (International ed. in English)》2016,55(14):4504-4508
A cyclic octapeptide composed of hydroxy‐functionalized γ‐amino acids folds in a “V‐shaped” conformation that allows the selective recognition of anions such as chloride, nitrate, and carbonate. The process involves the simultaneous self‐assembly of six peptide subunits and the recognition of four anions to form a tetrahedral structure, in which the anions are located at the corners of the resulting structure. Each anion is coordinated to three different peptides. The structure was fully characterized by several techniques, including NMR spectroscopy and X‐ray diffraction, and the material was able to facilitate the transmembrane transport of chloride ions. 相似文献
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Dr. Carlos Mas‐Moruno Roberta Fraioli Dr. Florian Rechenmacher Dr. Stefanie Neubauer Dr. Tobias G. Kapp Prof. Dr. Horst Kessler 《Angewandte Chemie (International ed. in English)》2016,55(25):7048-7067
Engineering biomaterials with integrin‐binding activity is a very powerful approach to promote cell adhesion, modulate cell behavior, and induce specific biological responses at the surface level. The aim of this Review is to illustrate the evolution of surface‐coating molecules in this field: from peptides and proteins with relatively low integrin‐binding activity and receptor selectivity to highly active and selective peptidomimetic ligands. In particular, we will bring into focus the difficult challenge of achieving selectivity between the two closely related integrin subtypes αvβ3 and α5β1. The functionalization of surfaces with such peptidomimetics opens the way for a new generation of highly specific cell‐instructive surfaces to dissect the biological role of integrin subtypes and for application in tissue engineering and regenerative medicine. 相似文献
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Frank Deubel Victor Bretzler Richard Holzner Tobias Helbich Oskar Nuyken Bernhard Rieger Rainer Jordan 《Macromolecular rapid communications》2013,34(12):1020-1025
The straightforward synthesis of a series of poly(thioether)s by photoinduced thiol‐ene click polyaddition of α,ω‐alkylene thiols is reported. It is found that linear and telechelic poly(thioether)s can be directly obtained from α,ω‐alkylene thiols with, for example, alkyl chain length of m = 1,2,3, and 9. The reaction proceeds without additives such as (radical) initiators or metal compounds and can simply be carried out by UV‐irradiation of the bulk monomer or monomer solution. Ex situ kinetic studies reveal that the reaction proceeds by a typical a step‐growth polyaddition mechanism. As the homologue series of poly(thioether)s are now synthetically accessible, new direct pathways to tailored poly(alkyl sulphoxide)s and poly(alkyl sulfone)s are now possible.