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Search for "glycoconjugates" in Full Text gives 86 result(s) in Beilstein Journal of Organic Chemistry.
Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles
Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2
- system was then used for the detection of amyloid-β peptides [74], whose aggregation is responsible for Alzheimer’s disease [75]. In 2014, Fairbanks and co-workers reported a one-pot aqueous compatible method for making various triazole-linked glycoconjugates via intermediate glycosyl azides, which then
Electron-deficient pyridinium salts/thiourea cooperative catalyzed O-glycosylation via activation of O-glycosyl trichloroacetimidate donors
Beilstein J. Org. Chem. 2017, 13, 2385–2395, doi:10.3762/bjoc.13.236
- crucial class of biomolecules such as oligosaccharides and glycoconjugates, where one sugar unit is linked with another sugar unit or any other molecules (aglycons) [1][2][3][4]. Owing to their high importance, several efficient protocols have been developed for the stereoselective glycosylation in the
Preactivation-based chemoselective glycosylations: A powerful strategy for oligosaccharide assembly
Beilstein J. Org. Chem. 2017, 13, 2094–2114, doi:10.3762/bjoc.13.207
- insight into the reaction mechanism, which is critical for efforts to enhance the glycosylation yield. The preactivation strategy is a powerful method for glycoassembly, which is evident from the successful synthesis of many complex oligosaccharides and glycoconjugates. However, glycosylation reactions
Intramolecular glycosylation
Beilstein J. Org. Chem. 2017, 13, 2028–2048, doi:10.3762/bjoc.13.201
- synthesis of a variety of oligosaccharides and glycoconjugates containing challenging β-mannosides [95][96]. A very impressive application of the IAD in polymer-supported reactions has also emerged [97]. Interestingly, the PMB tether was although used as the linker for the attachment to the polymer support
Enzymatic synthesis of glycosides: from natural O- and N-glycosides to rare C- and S-glycosides
Beilstein J. Org. Chem. 2017, 13, 1857–1865, doi:10.3762/bjoc.13.180
- of rare or unnatural glycosidic linkages. Keywords: enzyme; glycochemistry; glycoside hydrolase; glycosyltransferase; mechanism; Introduction The role of glycoconjugates is of prime importance, as they are nowadays well known to mediate many biological processes [1]. As a consequence, in a recently
- this goal, the glycoscientists will have to collaborate strongly to obtain pure and well-defined glycoconjugates. Indeed, even if during the last century, the chemists have engaged great efforts to successfully develop efficient means of synthesis of carbohydrate derivatives, through the use of
- the fast screening of their activities, as well as powerful molecular modelling and crystallization of proteins. No doubt then that such biocatalysts will represent a competitive tool for glycosylation so to obtain complex O-, S- or C-glycoconjugates of biological interests. Mechanisms of O-GTs
Strategies toward protecting group-free glycosylation through selective activation of the anomeric center
Beilstein J. Org. Chem. 2017, 13, 1239–1279, doi:10.3762/bjoc.13.123
- unactivated carbohydrates to form glycoconjugates. Furthermore, this reaction operates under neutral conditions further increasing its power and potential for widespread application in protecting-group-free glycosylations. However, there are mainly two obvious drawbacks of the operation: First, the formation
Aqueous semisynthesis of C-glycoside glycamines from agarose
Beilstein J. Org. Chem. 2017, 13, 1222–1229, doi:10.3762/bjoc.13.121
- employed in drug discovery. A part of our group has utilized this type of approach for the synthesis of dihydropyridine glycoconjugates [9] and antiviral sulfated alkylglycosides [10]. In an effort to amplify the utility of AnGal as a starting material for the synthesis of bioactive compounds, we have
Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience
Beilstein J. Org. Chem. 2017, 13, 1145–1167, doi:10.3762/bjoc.13.114
- characterization, the lectin, BC2L-C was shown to be composed of two distinct domains, each displaying unique specificities and biological activities. The protein is a super lectin that binds independently to fucosylated human histo-blood group epitopes and to mannose/heptose glycoconjugates. The N-terminal domain
An eco-compatible strategy for the diversity-oriented synthesis of macrocycles exploiting carbohydrate-derived building blocks
Beilstein J. Org. Chem. 2017, 13, 1106–1118, doi:10.3762/bjoc.13.110
- ][47][48]. There are several reports wherein different strategies have been developed and used for the synthesis of glycoconjugates [9][49][50][51], however, the combination of a CuAAC and a RCM reaction has been used very little and rarely combinations of these reactions have been used for the
- synthesis of sugar-embedded glycoconjugates [52][53]. Further, the linear syntheses of macrocycles based on multistep protocols are not cost-effective and the development of efficient, sustainable, greener and economical methods is highly desired. Synthetic methods to produce a diverse collection of
Glyco-gold nanoparticles: synthesis and applications
Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100
- highly immunogenic proteins. Another example on the importance of the way in which glycoconjugates are presented through NPs, regards the design and construction of GAuNPs decorated with mucin-related glycans for cancer immunotherapy [57]. A monomolecular sugar coating do not represent well the structure
O-Alkylated heavy atom carbohydrate probes for protein X-ray crystallography: Studies towards the synthesis of methyl 2-O-methyl-L-selenofucopyranoside
Beilstein J. Org. Chem. 2016, 12, 2828–2833, doi:10.3762/bjoc.12.282
- fucosides are generally α-linked across all kingdoms of life, in glycoproteins, glycolipids, bacterial lipopolysaccharides, or low-molecular weight glycoconjugates such as glycosylated natural products. β-Linked fucosides are rarely observed, for example in the bacterial polysaccharide colanic acid [39][40
Synthesis and NMR studies of malonyl-linked glycoconjugates of N-(2-aminoethyl)glycine. Building blocks for the construction of combinatorial glycopeptide libraries
Beilstein J. Org. Chem. 2016, 12, 1939–1948, doi:10.3762/bjoc.12.183
- ) and 3-oxo-3-(2-acetamido-2-deoxy-3,4,6-tetra-O-acetyl-β-D-galactopyranosylamino)propanoic acid (6d), respectively. The resulting AEG glycoconjugates 1a–d were converted into the corresponding free acids 2a–d in 97–98% yield by treatment with aqueous formic acid. The Fmoc group of compound 1c was
- determine the coalescence temperature which resulted in calculated rotation barriers of 17.9–18.3 kcal/mol for the rotamers. Keywords: amino acids; carbohydrates; glycoconjugates; glycopeptides; N-(2-aminoethyl)glycine; Introduction The glycocalyx is a fringy or fuzzy polysaccharide layer coating most
- specific glycoconjugates from natural sources remains a difficult, sometimes even an unrealizable task, for naturally occurring saccharides exhibit micro-heterogenity which makes it nearly impossible to obtain pure material from such sources. Chemical or chemoenzymatic syntheses of complex oligosaccharides
Synthesis and in vitro cytotoxicity of acetylated 3-fluoro, 4-fluoro and 3,4-difluoro analogs of D-glucosamine and D-galactosamine
Beilstein J. Org. Chem. 2016, 12, 750–759, doi:10.3762/bjoc.12.75
- analogs 6–8 are new compounds and their influence on the cell-surface glycan biosynthesis is currently being studied. We anticipate that 1,6-anhydro-2-azido-fluorohydrins 20, 21, 26 and 31 will find use as building blocks for the synthesis of fluorinated oligosaccharides and other glycoconjugates because
Towards inhibitors of glycosyltransferases: A novel approach to the synthesis of 3-acetamido-3-deoxy-D-psicofuranose derivatives
Beilstein J. Org. Chem. 2015, 11, 1547–1552, doi:10.3762/bjoc.11.170
- of enzymes that are responsible for the biosynthesis of complex oligosaccharides, glycoproteins and other glycoconjugates in mammalian biological systems. These glycoconjugates are operating in the cell and on the cell surface, particularly as glycoproteins, and are involved in many vital biological
- processes, such as cell–cell communication, signal transduction, activation and response of the immune system etc. [1][2]. On the other hand, an uncontrolled glycosylation caused by genetic mutations of GTs leads to structural changes in various glycoconjugates which contribute to many mammalian diseases [3
- ][4]. In addition, the role played by the glycoconjugates changes markedly during disease development such as malignant transformation [5], cancer cell proliferation and metastases spreading [6]. Since glycosyltransferases (GTs) are entailed in the biosynthesis of glycans and glycoconjugates, which
Are D-manno-configured Amadori products ligands of the bacterial lectin FimH?
Beilstein J. Org. Chem. 2015, 11, 1096–1104, doi:10.3762/bjoc.11.123
- ]. However, we could show that the Amadori rearrangement, when applied to selected aldoses as starting materials, is a high yielding and efficient synthetic approach towards C-glycosyl-type glycoconjugates. For example, when aldoheptoses are employed as starting material for the Amadori rearrangement, the
- in one step and without the need of protecting group manipulations. This is intriguing in light of biorthogonal ligation methodology as Amadori products are structurally closely related to naturally occurring D-hexopyranosides. In addition, C-glycosyl glycoconjugates are believed to bear great
- efficient and versatile approach towards D-manno-configured C-glycosyl-type glycoconjugates. In our study, we have employed two different amines in the Amadori rearrangement with 8, propargylamine and aniline. Under typical conditions for this reaction [2] 1-progargylamino-1-deoxy-D-manno-heptulose 9 and 1
Glycodendrimers: tools to explore multivalent galectin-1 interactions
Beilstein J. Org. Chem. 2015, 11, 739–747, doi:10.3762/bjoc.11.84
- activity through multivalent interactions with cell surface glycoconjugates [1][2][3][4]. Galectin-1 is a non-covalent homodimer that belongs to a family of β-galactoside binding proteins called galectins [5][6][7]. The monomeric units are oriented such that the two carbohydrate recognition domains are
- glycoconjugates to mediate biological activity [10][11][12][13][14][15][16]. Specifically, galectin-1 has been reported to be involved in multivalent mechanisms that cluster cell surface glycoproteins [10][17], cross-link receptors [13][18], and form lattices and larger aggregates [12][19][20]. Synthetic
- of glycoconjugates (TF antigen Mucin-1) on adjacent cells which directly facilitates aggregation; and (ii) clustering of receptors (TF antigen Mucin-1) which exposes adhesion molecules that interact with adhesion molecules on neighboring cells to cause aggregation. All four generations of the
DNA display of glycoconjugates to emulate oligomeric interactions of glycans
Beilstein J. Org. Chem. 2015, 11, 707–719, doi:10.3762/bjoc.11.81
- co-workers elegantly extended the utility of SELEX [30] to generate aptamers functionalized with glycans through CuAAC [31][32]. Their approach, termed SELMA (selection with modified aptamers), is a multistep procedure that allows screening, selection and amplification of DNA glycoconjugates (Scheme
- instructions. To this end a pilot library of fourteen PNA-tagged glycoconjugates that included mannose disaccharides joined by linkers of different lengths were paired through hybridization, varying the ligand combinations and interligand distances. Measuring the affinity of 32 different assemblies against
- in the glycans. DC-SIGN is a tetrameric lectin implicated in interactions with a broad array of pathogens including HIV. A library of 37,485 assemblies was prepared by hybridization of two sets of PNA-tagged glycoconjugates onto a library of DNA templates (Figure 4). Screening the library by affinity
Synthesis of carbohydrate-scaffolded thymine glycoconjugates to organize multivalency
Beilstein J. Org. Chem. 2015, 11, 668–674, doi:10.3762/bjoc.11.75
- on the cell surface. Thus many synthetic multivalent glycoconjugates have been developed as important tools for glycobiological research. We are expanding this collection of molecules by the introduction of carbohydrate-scaffolded divalent glycothymine derivatives that can be intramolecularily
- ] photocycloaddition; carbohydrate scaffolds; multivalency; thymine glycoconjugates; Introduction Multivalency of molecular interactions is a fundamental principle in carbohydrate recognition. It influences the avidity and specificity of carbohydrate–protein interactions as well as it enables supramolecular changes
- galectin-mediated organization of cell surface glycoconjugates influences glycan dynamics and essential biological processes like signaling [8]. Therefore, in order to advance our understanding of carbohydrate-mediated biological response, we are seeking further molecular architectures that allow us
Electrochemical oxidation of cholesterol
Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45
- reaction carried out with 1,2:3,4-di-O-diisopropylidene-α-D-galactopyranose yielded glycoconjugate 23 with an ether bond between the sugar and steroid molecules. In further studies on the preparation of glycoconjugates from 3β-hydroxy-Δ5-steroids, various derivatives were applied, such as thioethers [44
- electrochemical acetoxylation of cholesterol at the allylic position. Direct anodic oxidation of cholesterol in dichloromethane. A plausible mechanism of the electrochemical oxidation of cholesterol in dichloromethane. The electrochemical formation of glycosides and glycoconjugates. Efficient electrochemical
3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates
Beilstein J. Org. Chem. 2015, 11, 162–168, doi:10.3762/bjoc.11.16
- /bjoc.11.16 Abstract 3α,5α-Cyclocholestan-6β-yl alkyl and aryl ethers were proved to be efficient cholesteryl donors in the electrochemical synthesis of glycoconjugates. 3α,5α-Cyclocholestan-6β-ol (i-cholesterol) and its tert-butyldimethylsilyl ether can also be used for this purpose. The i-cholesterol
- glycoconjugates from 3β-hydroxy-Δ5-steroids (sterols). The method consists of electrooxidation of a proper cholesterol derivative in the presence of an unactivated sugar with a free hydroxy group at the anomeric position (formation of glycosides) or at any other position (preferentially a primary position) that
- leads to sterol glycoconjugates. Initially, the reaction of cholesterol (1) with various sugars was studied. During anodic oxidation of cholesterol in dichloromethane (the choice of solvent is crucial as the reaction course may be different in other solvents) [1], splitting of the carbon–oxygen bond in
Synthesis and biological evaluation of a novel MUC1 glycopeptide conjugate vaccine candidate comprising a 4’-deoxy-4’-fluoro-Thomsen–Friedenreich epitope
Beilstein J. Org. Chem. 2015, 11, 155–161, doi:10.3762/bjoc.11.15
- selective IgG antibodies that are cross-reactive with native MUC1 epitopes on MCF-7 human cancer cells. Keywords: cancer immunotherapy; fluorinated carbohydrates; glycoconjugates; MUC1; TACA; Introduction Since cancer has advanced to one of the leading causes of death in economical developed countries
- tumor cells [32]. In this context and as part of ongoing research devoted to the development of selectively fluorinated MUC1 glycopeptide-based vaccines, we report herein on the successful preparation of two novel MUC1 glycoconjugates comprising 4’-deoxy-4’-fluoro-TF antigen side chains in their B cell
Synthesis of divalent ligands of β-thio- and β-N-galactopyranosides and related lactosides and their evaluation as substrates and inhibitors of Trypanosoma cruzi trans-sialidase
Beilstein J. Org. Chem. 2014, 10, 3073–3086, doi:10.3762/bjoc.10.324
- -sialic acid [10]. Although TcTS can be considered as “promiscuous” with respect to the sialyl donor and the β-galactopyranoside acceptor, it should be noted that the reaction is in fact specific in vivo. Only sialic acid-linked α(2→3) to β-galactopyranosides in glycoconjugates is transferred to terminal
Synthesis of aromatic glycoconjugates. Building blocks for the construction of combinatorial glycopeptide libraries
Beilstein J. Org. Chem. 2014, 10, 2453–2460, doi:10.3762/bjoc.10.256
- linked to the backbone by a malonyl moiety were prepared via peptide coupling. The orthogonally protected glycoconjugates, bearing an acetyl-protected glycoside, were converted into their corresponding acids which are suitable building blocks for combinatorial glycopeptide synthesis. Keywords: amino
- acids; aniline; carbohydrates; glycoconjugates; glycopeptides; Introduction Glycans or other complex oligosaccharide structures, present on the surface of every prokaryotic and eukaryotic cell, are important for a large number of biological recognition processes like, for example, intercellular
Synthesis and immunological evaluation of protein conjugates of Neisseria meningitidis X capsular polysaccharide fragments
Beilstein J. Org. Chem. 2014, 10, 2367–2376, doi:10.3762/bjoc.10.247
- the native polymer and conjugated to the same protein. This finding suggests that oligomers longer than three repeating units are possibly needed to mimic the activity of the native polysaccharide. Keywords: carbohydrates; glycoconjugates; immunology; multivalent glycosystems Neisseria meningitidis
- in vivo immunological evaluation of neo-glycoconjugates from the fragments 1–3. In this context, we describe the significant improvements recently achieved in some crucial steps of our previously reported synthesis [25] that will render more expeditious the preparation of this type of oligomers. The
- be efficiently utilized for the conjugation of short synthetic antigens bearing an amino spacer [26][27]. The synthesized CRM197 glycoconjugates were first tested for their capability of eliciting anti MenX CPS antibodies in mice. The functional activity of the generated antibodies was then assessed
Multivalent glycosystems for nanoscience
Beilstein J. Org. Chem. 2014, 10, 2345–2347, doi:10.3762/bjoc.10.244
- molecular shaping. They adopt more forms and shapes than one can conceive in 24 hours. They exist as small mono- or oligo-saccharides, as large and highly complex polysaccharides, and in conjugation with, for example, proteins and lipids, forming a kingdom of glycoconjugates that are found on every cell
- disease. Consequently, the glycosciences have gained great respect in chemistry and biology. It is now generally considered important to be able to synthesize carbohydrates and glycoconjugates, to purify and analyze their structures, and to advance our understanding of the biology of carbohydrates in
- to achieve potential innovations offered by glycoconjugates. Since 2011, approximately 70 group leaders from 21 countries have gathered in an international COST (European Cooperation in Science and Technology) Action, funded by the European Union (EU) to address the challenges and opportunities in
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