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A novel metal–organic framework functionalized with amino and triazole moieties, namely Zn-TDA, has been synthesized. It represents the first example of a MOF-based sensor for highly selective sensing of cellobiose over other saccharides. Furthermore, Zn-TDA was used as a catalyst for the conversion of cellobiose to 5-hydroxymethylfurfural (5-HMF), achieving an excellent yield of 68.7% within 90 min under mild conditions. [ABSTRACT FROM AUTHOR]

Synthesis of Galβ1 → 3GlcNAc-repeating saccharides is limited mainly by the formation of less-reactive oxazolines. We herein report an expeditious approach that requires trichloroacetyloxazolines as reactive glycosyl donors. Using only two disaccharide building blocks, the iterative oxazoline formation and glycosylation synthesized hexa- and octasaccharides with overall yields of 47% and 26% in four and six steps, respectively. [ABSTRACT FROM AUTHOR]

We here describe the synthesis and biological evaluation of glycan shields for cell penetrating peptides. A new benzyl alkoxyamine connector was employed for the coupling of two saccharides units in the lateral side chain of individual amino acids in a peptide sequence. The oxyme bond formation with the corresponding glycan aldehydes allowed the preparation of highly glycosylated penetrating peptides with a minimal synthetic effort. Surprisingly, it was found that a four to six saccharide substitution did not decrease uptake efficiency in cells, whereas it significantly improved the toxicity profile of the penetrating peptide. In particular, glucose substitution was confirmed as an optimal glycan shield that showed an excellent in vitro uptake and intracellular localization as well as a superior in vivo biodistribution. [ABSTRACT FROM AUTHOR]

We synthesized "glyco-arylopeptides", whose folding structure significantly changes depending on the kind of saccharide in their side chain. The saccharide moiety interacts with the main chain via hydrogen bonding, and the non-natural polypeptides form two well-defined architectures—(P)-31- and (M)-41-helices—depending on the length of the saccharide chains and even the configuration of a single stereo-genic center in the epimers. [ABSTRACT FROM AUTHOR]

Carbohydrates (glycans, saccharides, sugars) are everywhere. In fact, glycan–protein interactions are involved in many essential processes of life and disease. The understanding of the key structural details at the atomic and molecular level is of paramount importance to effectively design molecules for therapeutic purposes. Different approximations may be employed to decipher these molecular recognition processes with high resolution. Advances in cryo-electron microscopy are providing exquisite details on different biological mechanisms involving sugars, while better and better protocols for structural refinement in the application of X-ray methods for protein–sugar complexes and glycoproteins are also permitting fantastic advances in the glycoscience arena. Alternatively, NMR spectroscopy remains as one of the most rewarding techniques to explore protein–carbohydrate interactions. In fact, given the intrinsic dynamic nature of saccharides, NMR can afford exquisite structural information at the atomic detail, not accessible by other techniques. However, the access to this information is sometimes intricate, and requires careful analysis and well-defined strategies. In this review, we have highlighted these issues and presented an overview of different modern NMR approaches with a focus on the latest developments and challenges. [ABSTRACT FROM AUTHOR]

Selective glucose binding was identified through five generations of monoboronic acid-functionalized PAMAM dendrimers. The best selectivity obtained when using G3 dendrimers (1b) generated 71.1, 94.9, and 1309 times stronger binding than when using galactose, fructose, and lactose, respectively. Further experiments using dendrimer analogues and glucose derivatives suggested that two nearby monoboronic acids cooperatively bound one glucose. [ABSTRACT FROM AUTHOR]

A new simple protocol, using TMSNTf2 or Tf2NH as the catalyst, for the activation of trichloroacetimidate donors is described. This O-glycosylation proceeds with stereospecific inversion of the donor configuration. The scope of the protocol has been investigated using common glycosyl donors reacting with simple alcohols as well as sugar acceptors. [ABSTRACT FROM AUTHOR]

We present a concept to modulate near infrared photoluminescence (NIR-PL) from locally-functionalized single-walled carbon nanotubes (local-f-SWNTs) based on a molecular recognition approach using newly synthesized phenylboronic acid (PB)-functionalized local-f-SWNTs (PB-SWNTs) and saccharides, in which a selective PL spectral shift is observed by addition of the saccharides. [ABSTRACT FROM AUTHOR]

C-Glycosylation of glycosyl ortho-hexynylbenzoates with allyltrimethylsilane or silyl enol ethers could proceed smoothly under the catalysis of Ph3PAuNTf2 to provide the corresponding C-glycosides in high yields and stereoselectivity, wherein the moisture sequestered by the molecular sieves was disclosed to play a critical role in the gold(i)-catalytic cycle. [ABSTRACT FROM AUTHOR]

Low temperature 1H- and 19F-DOSY have been used for analyzing reactive intermediates in glycosylation reactions, where a glycosyl trichloroacetimidate donor has been activated using different catalysts. The DOSY protocols have been optimized for low temperature experiments and provided new insight into acid catalyzed glycosylation chemistry. From the study a new glycosylation intermediate was characterized. [ABSTRACT FROM AUTHOR]

Mono-, di- and trisaccharide derivatives of 1,2-unsaturated N-acetyl-d-glucal have been synthesized and shown to function as tight-binding inhibitors/slow substrates of representative hexosaminidases. Turnover is slow and not observed in the thioamide analogue, allowing determination of the 3-dimensional structure of the complex. Inhibition is insensitive to pH and to mutation of key catalytic residues, consistent with the uncharged character of the inhibitor. These properties could render this inhibitor class less prone to development of resistance. [ABSTRACT FROM AUTHOR]

Transmission electron microscopy, mass spectrometry, and drift tube ion mobility-mass spectrometry are used to study the assemblies formed by the metamorphic chemokine lymphotactin in the presence of a model pentameric glycosaminoglycan, fondaparinux. This combination of techniques delineates significant differences in the complexes observed for two forms of the full length protein as well as a truncated form, without the intrinsically disordered C-terminal tail, over a length scale from few nm to μm assemblies. [ABSTRACT FROM AUTHOR]

The fabrication of a molecularly tailored surface functionalised with a saccharide binding motif, a phenyl boronic acid derivative is reported. The functionalised surface facilitated the transfer of electrons, via unique electronic interactions mediated by the presence of the boronic acid, from a macrophage cell line. This is the first example of eukaryotic cellular-electrical communication mediated by the binding of cells via their cell–surface saccharide units. [ABSTRACT FROM AUTHOR]

A new strategy for the fabrication of glycosaminoglycan (GAG) analogs was proposed by copolymerizing the sulfonated unit and the glyco unit, ‘splitted’ from the sulfated saccharide building blocks of GAGs. The synthetic polymers can promote cell proliferation and neural differentiation of embryonic stem cells with the effects even better than those of heparin. [ABSTRACT FROM AUTHOR]

The multigram-scale synthesis of a sulfation-site programmed heparin-like dodecasaccharide is described. Evaluation alongside dodecasaccharides lacking this single glucosamine O6-sulfation, or having per-O6-sulfation, shows that site-specific modification of the terminal glucosamine dramatically interconverts regulation of in vitro and in vivo biology mediated by the two important chemokines, CXCL12 (SDF1α) or CXCL8 (IL-8). [ABSTRACT FROM AUTHOR]

This work describes a novel mono-boronic acid derivative of a tricarbocyanine. The probe is a genuine near-infrared fluorescence emitter with improved properties such as a large Stokes shift, excellent water solubility and sensitive fluorogenicity upon binding to carbohydrates under physiological conditions. [ABSTRACT FROM AUTHOR]

Saccharides and temperature dual-responsive hydrogels have been prepared based on PNIPAAm copolymers containing phenylboronic acid (PBA) groups and used for harvesting cell sheets. The cell sheet could be released from the hydrogel layer at 37 °C simply by increasing sugar concentration, and could be more efficiently released at a lower temperature and elevated sugar concentration. [ABSTRACT FROM AUTHOR]

The glycosylation reactions of glycosyl trichloroacetimidates and several alcohols using an organophotoacid as an activator under photoirradiation proceeded smoothly to give the corresponding glycosides in high yields. The organophotoacid was recovered and reused without any loss of efficiency. [ABSTRACT FROM AUTHOR]

Synthesis of amphiphilic, cyclic di- and tetrasaccharides, which incorporate a methylene moiety at the inter-glycosidic bond, is reported. The amphiphilic properties of the new cyclic tetrasaccharide host were identified through assessing the solubilities of guests in aqueous and in organic solvents. The glycosidic bond stability of the cyclic tetrasaccharide under aqueous acidic condition was also verified. [ABSTRACT FROM AUTHOR]

Corrections to articles including "A reassessment of the association between azulene and [60]fullerene. Possible pitfalls in the determination of binding constants through fluorescence spectroscopy" in the 2008 issue, "A facile surfactant critical micelle concentration determination" in the 2011 issue, and "Sweet (hetero)aromatics: glycosylated templates for the construction of saccharide mimetics" in the 2011 issue, are presented.

In this feature article the use of boronic acids to monitor, identify and isolate analytes within physiological, environmental and industrial scenarios is discussed. Boronic acids recognise diol motifs through boronic ester formation and interact with anions generating boronates, as such they have been exploited in sensing and separation protocols for diol appended molecules such as saccharides and anions alike. Therefore robust molecular sensors with the capacity to detect chosen molecules selectively and signal their presence continues to attract substantial attention, and boronic acids have been exploited with some success to monitor the presence of various analytes. Reversible boronic acid-diol interactions have also been exploited in boron affinity chromatography realising new separation domains through the same binding events. Boronic acid diol and anion interactions pertaining to sensing and separation are surveyed. [ABSTRACT FROM AUTHOR]

A coordination network composed of a mannose-based organic ligand and a sodium ion, ‘sugar sponge’, was synthesized for the crystalline sponge analysis of hydrophilic compounds. Owing to multiple hydrogen-bonding interactions, hydrophilic guests are firmly trapped in the 1-dimensional channel. The sugar sponge was utilized to analyze the structures of flexible alcohol and absolute configurations of chiral epoxides. [ABSTRACT FROM AUTHOR]

We report a saccharide recognition system by modifying responsive copolymers on the solid-based multiple nanochannels. The ion transport through nanochannels can be regulated by ultra-low concentration of saccharides, which can switch nanochannels between the “on” and “off” states. [ABSTRACT FROM AUTHOR]

Saccharides in water are detected electrically using an extendedgate type organic field effect transistor (OFET) functionalised by a phenylboronic acid monolayer. The response patterns of the monosaccharides are significantly different, suggesting that OFET devices can successfully read out the saccharide recognition behaviour of boronic acids and be potentially applied to healthcare devices modified with supramolecular receptors. [ABSTRACT FROM AUTHOR]

A novel thiol fluorophore was synthesized to be selectively attached to the non-reducing end of low molecular weight heparin (LMWH) via a Michael addition. Double labeling of LMWH was demonstrated to be a feasible approach for the determination of heparinase II activity by FRET. [ABSTRACT FROM AUTHOR]

A concise and highly efficient strategy for the synthesis of N-glycosyl imidazole analogues is reported. This reaction is based on a palladium catalysed decarboxylative allylation and three steps, namely, carbamation, decarboxylation and allylation are involved. All the substrates can afford the desired products with excellent yields and selectivities. [ABSTRACT FROM AUTHOR]

Integrated and insulated boronate-based fluorescent probes have been evaluated for the detection of hydrogen peroxide in the presence of saccharides. [ABSTRACT FROM AUTHOR]

Metabolic chemical reporters of glycosylation allow for the visualization and identification of a variety of glycoconjugates by taking advantage of the promiscuity of carbohydrate metabolism. Here we describe the synthesis and characterization of metabolic chemical reporters bearing an N-propargyloxycarbamate (Poc) group that creates discrimination between glycosylation pathways. [ABSTRACT FROM AUTHOR]

A combinatorial ionic-liquid-supported “catch-and-release” strategy for oligosaccharide synthesis (combi-ICROS) is reported. A series of β-(1→6) glucan di-, tri- and tetra-saccharides were synthesized in one pot to showcase the versatility of the strategy. [ABSTRACT FROM AUTHOR]

The structure of the pentasaccharide S259-1in the Consortium for Functional Glycomics was investigated using a variety of techniques. Surprisingly, the structure differs from the structure assumed from the previously established specificity of the human fucosyltransferase FUT-III used in the last step of chemoenzymatic synthesis. When presented with a tetrasaccharide substrate containing both type I and type II disaccharide moieties, the enzyme generates a pentasaccharide in which the type II moiety is preferentially fucosylated. The unexpected product generated by FUT-III in this case highlights the importance of performing detailed structural analysis on products generated by enzymes. [ABSTRACT FROM AUTHOR]

By incorporating NOO tridentate chelators into rationally designed ligand systems, a well-defined molecular cube Ce-TBDS and a bicoronal trigonal prism Ce-TBBS were achieved viaself-assembly and the luminescence recognition of natural saccharides with Ce-TBBS were also investigated. [ABSTRACT FROM AUTHOR]

Mono- and diglycosylated aromatics and heteroaromatics may serve as building blocks for the construction of metabolically stable mimetics of oligosaccharides. Methods for their preparation from monosaccharidic precursors by direct C-glycosylation, dipolar cycloaddition or Larock cyclization are described. [ABSTRACT FROM AUTHOR]

A Pd-based indicator displacement assay for the fluorimetric sensing of carbohydrates has been developed. The assay allows the detection of saccharides in the low millimolar concentration range in water at neutral pH. [ABSTRACT FROM AUTHOR]

A new solid acid, based on tantalum hydroxide, was used to catalyze saccharide dehydration into 5-hydroxymethylfurfural (HMF) with high catalytic activity and excellent stability in a water–2-butanol biphasic system. Furthermore, good results were also obtained from Jerusalem artichoke juice with the catalyst under the same conditions. [ABSTRACT FROM AUTHOR]

We report that dye-doped fluorescent silica nanoparticles (FSNPs) are highly efficient labels for glycans. Mono- and oligo-saccharides were conjugated to FSNPs using a general photocoupling chemistry. FSNP-labeled glycans were applied to image and detect bacteria, and to study carbohydrate–lectin interactions on a lectin microarray. [ABSTRACT FROM AUTHOR]

In this report, we describe the convergent synthesis of β(1,3) oligosaccharides containing an aminoalkyl group. The branched heptadecasaccharide and linear hexadecasaccharide acted as ligands of dectin-1 whose binding affinity was only 10-fold weaker than that of natural SPG and exhibited dectin-1 agonist activity. [ABSTRACT FROM AUTHOR]

Substantially enhanced monosaccharide fluorescent sensing in aqueous solutions using a simple phenylboronic acid receptor is achieved by coupling the classic strategy based on saccharide–boronic acid interaction with catalytic Suzuki homocoupling reaction. [ABSTRACT FROM AUTHOR]

The article offers information on the copper-catalyzed 1,3-dipolar cycloaddition (CLICK) reaction which is used for synthesis of saccharide decorated hard core of sugar balls. It includes reaction of an alkyne- functionalised metal complex with an organic azide to analyze the CLICK methodology. It mentions that nuclear magnetic resonance spectrum was employed for analyzing the acetyl signals.

New Ce-based Werner type tetrahedrons were achieved for sizeselectively luminescent detection of natural carbohydrates through incorporating amide groups as both the multiple hydrogen bonding triggers and binding-signalling transductor. [ABSTRACT FROM AUTHOR]

5-Hydroxymethylfurfural (HMF), one of the most important intermediates derived from biomass, was directly produced from monosaccharides (fructose and glucose) and disaccharides (sucrose and cellobiose) by a simple one-pot reaction including hydrolysis, isomerization and dehydration using solid acid and base catalysts under mild conditions. [ABSTRACT FROM AUTHOR]

Stable methyl glycosides are identified as glycosyl donors in the presence of AuBr3 in acetonitrile; a panel of aglycones comprising aliphatic, alicyclic, steroidal and sugar alcohols are examined successfully for the glycosylation reaction and methyl glycosides of di- and tri- saccharides are converted to corresponding tri- and tetra-saccharides exploiting salient features of our novel activation protocol. [ABSTRACT FROM AUTHOR]

Polymeric synthetic host 2, azacrown-attached 2,6-pyridylene ethynylene polymer, was investigated for its saccharide recognition and the additive effect of triethylene tetramine–trifluoroacetic acid; heteroallosteric effects were observed on the basis of CD and UVVis analyses, which indicated saccharide-dependent stabilization and destabilization of helical complexes by the formation of pseudopolyrotaxanes. [ABSTRACT FROM AUTHOR]

Stable methyl glycosides are identified as glycosyl donors in the presence of AuBr3in acetonitrile; a panel of aglycones comprising aliphatic, alicyclic, steroidal and sugar alcohols are examined successfully for the glycosylation reaction and methyl glycosides of di- and tri- saccharides are converted to corresponding tri- and tetra-saccharides exploiting salient features of our novel activation protocol. [ABSTRACT FROM AUTHOR]

The fluorescence resonance energy transfer (FRET) between CdSe-ZnS QDs and fluorophore-labeled galactose or fluorophore-labeled dopamine linked to phenyl boronic acid-functionalized QDs is used to develop competitive assays for the optical detection of galactose, glucose, or dopamine. [ABSTRACT FROM AUTHOR]

Hydrogel spheres, fashioned from an operationally simple mould, that incorporate boronate units were shown to function as saccharide sensors. [ABSTRACT FROM AUTHOR]

The fluorescence resonance energy transfer (FRET) between CdSe–ZnS QDs and fluorophore-labeled galactose or fluorophore-labeled dopamine linked to phenyl boronic acid-functionalized QDs is used to develop competitive assays for the optical detection of galactose, glucose, or dopamine. [ABSTRACT FROM AUTHOR]

Hyperbranched polyglycerols (HPGs) are ideal scaffolds for the multivalent presentation of saccharides, due to their biocompatible, carbohydrate-like properties; here, we report the conjugation of galactosesugar moieties to HPG, and the multivalent effect of these constructs on selectin binding. [ABSTRACT FROM AUTHOR]

The layered transition-metal oxide HNbMoO6is demonstrated to exhibit remarkable catalytic performance for the hydrolysis of saccharides such as sucrose, cellobiose, starch, and cellulose, attributable to water tolerance and the facile accessibility of saccharides into the strong acidic interlayer gallery of the solid. [ABSTRACT FROM AUTHOR]

Various β-glycosyl azides have been synthesized directly in water by the reaction of unprotected sugars and sodium azide mediated by 2-chloro-1,3-dimethylimidazolinium chloride (DMC). [ABSTRACT FROM AUTHOR]

Correction for ‘Glycosylation enhances the aqueous sensitivity and lowers the cytotoxicity of a naphthalimide zinc ion fluorescence probe’ by Lei Dong et al., Chem. Commun., 2015, DOI: 10.1039/c5cc04357c. [ABSTRACT FROM AUTHOR]