- Iron(III) chloride catalyzed glycosylation of peracylated sugars with allyl/alkynyl alcohols
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In this work, the use of ferric chloride as an efficient catalyst in glycosylation reactions of sugars in the presence of allyl and alkynyl alcohols is described. The corresponding glycosides were obtained with moderate to good yields. This new procedure presented greater selectivity when compared to classic methods found in the literature. Principal features of this simple method include non-hazardous reaction conditions, low-catalyst loading, good yields and high anomeric selectivity.
- Narayanaperumal, Senthil,Da Silva, Rodrigo Ce?sar,Monteiro, Julia L.,Corre?a, Arlene G.,Paixa?o, Ma?rcio W.
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- Synthesis of a glycodendrimer incorporating multiple mannosides on a glucoside core
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The synthesis of a glycodendrimer by incorporating repetitive mannoside units onto a glucoside core was carried out to multivalently probe fundamental carbohydrate-protein interactions. The dendritic structure was constructed by a modified procedure that
- Wang, Chao,Sanders, Brian,Baker, David C.
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- Synthesis of the allelochemical alliarinoside present in garlic mustard (Alliaria petiolata), an invasive plant species in North America
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The allelochemical alliarinoside present in garlic mustard (Alliaria petiolata), an invasive plant species in North America, was chemically synthesized using an efficient and practical synthetic strategy based on a simple reaction sequence. Commercially available 1,2,3,4,6-penta-O-acetyl- β-d-glucopyranose was converted into prop-2-enyl 2,3,4,6-tetra-O-acetyl- β-d-glucopyranoside and subjected to epoxidation. In a one-pot reaction, ring-opening of the epoxide using TMSCN under solvent free conditions followed by treatment of the formed trimethylsilyloxy nitrile with pyridine and phosphoryl chloride, afforded the acetylated β-unsaturated nitriles (Z)-4-(2,3,4,6-tetra-O-β-d-glucopyranosyloxy)but-2-enenitrile and its isomer (E)-4-(23,4,6-tetra-O-β-d-glucopyranosyloxy)but-2-enenitrile. Deacetylation of Z- and/or E-isomers afforded the target molecules alliarinoside and its isomer.
- Olsen, Carl Erik,M?ller, Birger Lindberg,Motawia, Mohammed Saddik
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- A practical synthesis of 2,3,4,6-Tetra-O-acetyl-1-O-(2-propenyl)-β-D- glucopyranoside using ZnCl2
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2,3,4,6-Tetra-O-acetyl-1-O-(2-propenyl)-β-D-glucopyranoside (1a), which is a useful raw material in the synthesis of a bioactive agent, has been synthesized in 50% yield by reacting β-D-glucose pentaacetate and 3 mol equiv of an allyl alcohol with 0.9 mol equiv of ZnCl2 in toluene at 80°C for 2 h followed by recrystallization from diisopropyl ether. This method is suitable for the large-scale preparation of 1a due to its efficiency, safety, and cost-effectiveness.
- Yuasa, Yoko,Yuasa, Yoshifumi
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- Mannose/glucose-functionalized dendrimers to investigate the predictable tunability of multivalent interactions
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G4-, G5-, and G6-PAMAM dendrimers were functionalized with mixtures of mannose and glucose in varying ratios, and the relative affinities of these compounds for Concanavalin A (Con A) were evaluated using the hemagglutination assay. As the ratio of mannose to glucose increases, the relative activity in the hemagglutination assay (on a per sugar basis) increases linearly. Methyl mannose binds to Con A with an affinity 4-fold higher than that of methyl glucose; multivalency amplifies this trend. The mannose/glucose-functionalized dendrimer results reported here suggest that the affinity of multivalent associations can be attenuated in predictable, reliable ways based on monovalent affinities of the ligands. Copyright
- Wolfenden, Mark L.,Cloninger, Mary J.
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- A cyanoallyl glucoside from Alliaria petiolata, as a feeding deterrent for larvae of Pieris napi oleracea
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Alliarinoside, a feeding inhibitor against early instar larvae of Pieris napi oleracea, was isolated from the foliage of Alliaria petiolata and characterized as (2Z)-4-(β-D-glucopyranosyloxy)-2-butenenitrile (1) by spectroscopic methods. The structural assignment was confirmed by synthesis of peracetylated alliarinoside (2) and its 2E isomer (3). A sample of synthetic 1 was isolated by preparative HPLC from the hydrolysis of the 2Z acetate. Feeding inhibition assays showed comparable activity for the synthetic and natural glycosides.
- Haribal, Meena,Yang, Zhicai,Attygalle, Athula B.,Renwick, J. Alan A.,Meinwald, Jerrold
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- Preparation and characterization of N-chitosan derivatives
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Allyl glycosides of 8 simple sugars have been prepared and characterized, including 1H-and 13C-NMR assignments.Formylmethyl glycosides, obtained by reductive ozonolysis of the allyl glycosides, have been reductively N-alkylated to chitosan with typical yields of 80percent.The glycosides of α- and β-D-glucopyranose, α- and β-D-galactopyranose, 2-acetamido-2-deoxy-α- and β-D-glucopyranose, β-D-glucuronic acid, and β-lactose have been incorporated by this method.The degree of substitution (d.s.) of the products was controlled by varying the molar ratio of glycoside to free amine groups of chitosan by between 0.5 and 3.0.Derivatives of degree of substitution >0.3 were typically water soluble, and compounds of higher d.s. generally gave less-viscous aqueous solutions.Assignment of 13C-NMR chemical shifts verified the structure of these derivatives.The linewidths of the branch resonances (5-100 Hz) provided qualitative information about the relationship between d.s. and branch mobility.The resonances of high-d.s. products were narrower and more intense than analogous low-d.s. derivatives.The chitosan resonances of the backbone were generally broader (50-200 Hz) and less intense, and as a result were difficult to assign fully.
- Holme, Kevin R.,Hall, Laurance D.
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- Spin-labelled glycolipid analogues: D-glucose series
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Neoglycolipids bearing a paramagnetic probe in their lipophilic aglycon have been prepared. All belong to the D-glucose series, both anomers for the glucoside representatives, respectively β and α anomers in the S- and C-glucosyl series. Two different types of radical sites have been used, a relatively short-lived imino N-oxyl group for glucosides and a more stable N-acylamino N-oxyl moiety in the other cases. EPR spectra of these radical species afforded information on the conformation of the lipophilic chain in the vicinity of the paramagnetic probe.
- Tronchet,Zsely,Geoffroy
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- Photoinduced Thiol-ene Chemistry Applied to the Synthesis of Self-Assembling Elastin-Inspired Glycopeptides
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Synthetic (glyco)peptides inspired by proteins able to self-assemble are appealing biomaterials in the field of tissue engineering and regenerative medicine. Herein, for the first time, taking advantage of thiol-ene chemistry coupled to solid-phase peptide synthesis, a self-assembling peptide inspired by elastin protein was bioconjugated to three carbohydrates in order to obtain the corresponding glycopeptides. They were studied at the molecular and supramolecular level. The results show that the carbohydrate influences the molecular conformation of the glycopeptide and its self-aggregation properties as well. As future perspective, the results could enable us to tune the final self-aggregation properties of the glycopeptide by changing the sugar moiety.
- Piccirillo, Germano,Pepe, Antonietta,Bedini, Emiliano,Bochicchio, Brigida
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- A highly diastereoselective, practical synthesis of allyl, propargyl 2,3,4,6-tetra-O-acetyl-β-D-gluco, β-D-galactopyranosides and allyl, propargyl heptaacetyl-β-D-lactosides
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Commercially available β-D-glucopyranose pentaacetate, β-D- galactopyranose pentaacetate and β-D-lactose heptaacetate were reacted with propargyl alcohol in the presence of BF3-Et2O catalyst to obtain in high yield and selectivity, the corresponding propargyl derivatives, respectively. These were hydrogenated by use of Lindlar catalyst to give the corresponding allyl β-D-glycopyranosides in quantitative yield.
- Mereyala, Hari Babu,Gurrala, Srinivas Reddy
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- New modified single chained glycolipids. Part 1: Synthesis of deoxy and partially O-methylated glycolipids with or without a sulfur containing spacer
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A way to synthesize neoglycolipids with high yields and anomeric purity is described. Starting point of the synthesis strategy is the glycosylation of allyl alcohol with definite steric orientation. Introduction of the hydrophobic moiety was achieved by photoaddition of n-hexadecanethiol and 3-mercaptopropionic acid followed by amidation with n-hexadecylamine, respectively. In order to investigate the influence of different carbohydrate headgroups in the physicochemical behavior of the general glycolipid, especially the orientation of the alkyl chain, a range of neoglycolipids was synthesized. Beside the differences in the configuration between unfunctionalized glycopyranoses like D-glucose, D-galactose and D-mannose, a number of deoxy and partially O-methylated sugar derivatives was prepared. The divergences concerning the different carbohydrate headgroups and the hydrophobic moiety, respectively, can be compared to relatively simple structured glycolipids with hexadecyl residue and without spacer function.
- Schmidt,Chatterjee,Dobner,Nuhn
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- A high-yielding synthesis of allyl glycosides from peracetylated glycosyl donors
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β-Configured peracetylated sugars are often used as easily accessible glycosyl donors that are typically activated with common Lewis acids such as boron trifluoride or trimethylsilyltrifluoromethane sulfonate. Often these glycosylations occur with unsatisfactory yields due to incomplete reactions or extensive byproduct formation, primarily as a result of loss of an additional acetyl group generating partially unprotected glycosides. Here we report a simple glycosylation-reacetylation protocol for the generation of predominantly β-configured peracetylated allyl glucoside, -galactoside, -lactoside, and -maltoside with substantially improved reaction yields.
- Khamsi, Jamal,Ashmus, Roger A.,Schocker, Nathaniel S.,Michael, Katja
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- Increased Emulsion Stability for Reverse Y-Shaped Sugar-Based Surfactants
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A series of reverse Y-shaped surfactants containing aromatic and aliphatic linkers to combine two short hydrocarbon chains and one carbohydrate head group was prepared. Liquid crystalline behavior, air-water interfacial properties, and efficiency as an em
- Ali, Tammar Hussein,Tajuddin, Hairul Anuar Bin,Hussen, Rusnah Syahila Duali,Heidelberg, Thorsten
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- Synthesis of β-galactose-conjugated chlorins derived by enyne metathesis as galectin-specific photosensitizers for photodynamic therapy
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A first report on the synthesis and biological evaluation of the β-galactose-conjugated purpurinimides (a class of chlorins containing a six-membered fused imide ring system) as Gal-1 (galectin-1) recognized photosensitizers, prepared from purpurin-N-propargylimide via enyne metathesis, is discussed. On the basis of examination of the available crystal structure of the galectin-1 N-acetyllactose amine complex, it was considered that the chlorin-based photosensitizers could be introduced into a carbohydrate skeleton to expand the repertoire of the galectin-1-specific ligands. Preliminary molecular modeling analysis utilizing the modeled photosensitizers and the available crystal structures of galectin-carbohydrate complexes indicated that addition of the photosensitizer to the carbohydrate moiety at an appropriate position does not interfere with the galectin-carbohydrate recognition. Under similar drug and light doses, compared to the free purpurinimide analogue, the purpurinimides conjugated either with galactose or with lactose (Gal(β1-4)-Glc) produced a considerable increase in photosensitizing efficacy in vitro. This indicates the possibility for development of a new class of specific photosensitizers for photodynamic therapy (PDT) based on recognition of a cellular receptor.
- Zheng,Graham,Shibata,Missert,Oseroff,Dougherty,Pandey
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- Synthesis, kinetics and inhibition of Escherichia coli Heptosyltransferase I by monosaccharide analogues of Lipid A
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Gram-negative bacteria comprise the majority of microbes that cause infections that are resistant to pre-existing antibiotics. The complex cell wall architecture contributes to their ability to form biofilms, which are often implicated in hospital-acquired infections. Biofilms promote antibiotic resistance by enabling the bacteria to survive hostile environments such as UV radiation, pH shifts, and antibiotics. The outer membrane of Gram-negative bacteria contains lipopolysaccharide (LPS), which plays a role in adhesion to surfaces and formation of biofilms. The main focus of this work was the synthesis of a library of glycolipids designed to be simplified analogues of the Lipid A, the membrane embedded portion component of LPS, to be tested as substrates or inhibitors of Heptosyltransferase I (HepI or WaaC, a glycosyltransferase enzyme involved in the biosynthesis of LPS). Fourteen analogues were synthesized successfully and characterized. While these compounds were designed to function as nucleophilic substrates of HepI, they all demonstrated mild inhibition of HepI. Kinetic characterization of inhibition mechanism identified that the compounds exhibited uncompetitive and mixed inhibition of HepI. Since both uncompetitive and mixed inhibition result in the formation of an Enzyme-Substrate-inhibitor complex, molecular docking studies (using AutoDock Vina) were performed, to identify potential allosteric binding site for these compounds. The inhibitors were shown to bind to a pocket formed after undergoing a conformational change from an open to a closed active site state. Inhibition of HepI via an allosteric site suggest that disruption of protein dynamics might be a viable mechanism for the inhibition of HepI and potentially other enzymes of the GT-B structural class.
- Nkosana, Noreen K.,Czyzyk, Daniel J.,Siegel, Zarek S.,Cote, Joy M.,Taylor, Erika A.
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- Controlled In-Cell Generation of Active Palladium(0) Species for Bioorthogonal Decaging
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Owing to their bioorthogonality, transition metals have become very popular in the development of biocompatible bond-cleavage reactions. However, many approaches require design and synthesis of complex ligands or formulation of nanoparticles which often perform poorly in living cells. This work reports on a method for the generation of an active palladium species that triggers bond-cleaving reactions inside living cells. We utilized the water-soluble Na2PdCl4 as a simple source of PdII which can be intracellularly reduced by sodium ascorbate to the active Pd0 species. Once generated, Pd0 triggers the cleavage of allyl ether and carbamate caging groups leading to the release of biologically active molecules. These findings do not only expand the toolbox of available bioorthogonal dissociative reactions but also provide an additional strategy for controlling the reactivity of Pd species involved in Pd-mediated bioorthogonal reactions.
- Bernardes, Gon?alo J. L.,Day, Jason,Domingos, Josiel B.,Jiménez-Moreno, Ester,Kon?, Juraj,Latocheski, Eloah,Pérez, Laura Rodríguez,Sabatino, Valerio
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supporting information
(2022/01/11)
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- Synthesis, Conformational Analysis, and Complexation Study of an Iminosugar-Aza-Crown, a Sweet Chiral Cyclam Analog
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A new family of chiral C2 symmetric tetraazamacrocycles, coined ISAC for IminoSugar Aza-Crown, incorporating two iminosugars adopting a 4C1 conformation is disclosed. Multinuclear NMR experiments on the corresponding Cdsu
- Ardá, Ana,Blériot, Yves,Bordes, Alexandra,Désiré, Jér?me,Franconetti, Antonio,Guillard, Jer?me,Jiménez-Barbero, Jesús,Ménand, Micka?l,Perrin, Flavie,Poveda, Ana,Sollogoub, Matthieu,Tripier, Rapha?l,Troadec, Thibault
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supporting information
(2020/03/26)
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- Acid-Assisted Direct Olefin Metathesis of Unprotected Carbohydrates in Water
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The ability to use unprotected carbohydrates in olefin metathesis reactions in aqueous media is demonstrated. By using water-soluble, amine-functionalized Hoveyda–Grubbs catalysts under mildly acidic aqueous conditions, the self-metathesis of unprotected alkene-functionalized α-d-manno- and α-d-galactopyranosides could be achieved through minimization of nonproductive chelation and isomerization. Cross-metathesis with allyl alcohol could also be achieved with reasonable selectivity. The presence of small quantities (2.5 vol %) of acetic acid increased the formation of the self-metathesis product while significantly reducing the alkene isomerization process. The catalytic activity was furthermore retained in the presence of large amounts (0.01 mm) of protein, underlining the potential of this carbon–carbon bond-forming reaction under biological conditions. These results demonstrate the potential of directly using unprotected carbohydrate structures in olefin metathesis reactions under mild conditions compatible with biological systems, and thereby enabling their use in, for example, drug discovery and protein derivatization.
- Timmer, Brian J. J.,Ramstr?m, Olof
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supporting information
p. 14408 - 14413
(2019/11/11)
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- Glycosyl Aldehydes: New Scaffolds for the Synthesis of Neoglycoconjugates via Bioorthogonal Oxime Bond Formation
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The straightforward preparation of glycosyl neoconjugates by oxime (or hydrazone) bond formation represents a key bioorthogonal tool in chemical biology. However, when this strategy is employed by reacting the reducing end of the glycan moiety, the configuration and the stereochemical information is lost due to partial (or complete) opening of the glycan cyclic hemiacetal and the formation of the corresponding opened tautomers. We have completed the synthesis of a library of glycosyl aldehydes to be used as scaffold for the synthesis of neoglycoconjugates via oxime bond formation. These glycosyl aldehydes constitute a simple and accessible alternative to avoid loss of chiral information when conjugating, by oxime (or hydrazone) bonds, the aldehyde functionality present at the reducing end of natural carbohydrates.
- Reina, José J.,Rioboo, Alicia,Montenegro, Javier
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p. 831 - 845
(2018/01/11)
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- Chemical Synthesis of Modified Hyaluronic Acid Disaccharides
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Herein we report a chemical synthesis towards new modified hyaluronic acid oligomers by using only commercially available d-glucose and d-glucosamine hydrochloride. The various protected hyaluronic acid disaccharides were synthesized bearing new functional groups at C-6 of the β-d-glucuronic acid moiety with a view to structure-related biological activity tests. The orthogonal protecting group pattern allows ready access to the corresponding higher oligomers. Also, 1H NMR studies of the new derivatives demonstrated the effect of the various functional groups on the intramolecular electronic environment.
- Mende, Marco,Nieger, Martin,Br?se, Stefan
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supporting information
p. 12283 - 12296
(2017/09/14)
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- Sulfonated graphene oxide as highly efficient catalyst for glycosylation
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Heterogeneous sulfonated graphene oxide for the first time has been used as a green and efficient catalyst for atom-economic glycosylation of unprotected, unactivated glycosyl donors or 2,3,4,6-tetra-O-acetylglycosyltrichloroacetimidate with various accep
- Thombal, Raju S.,Jadhav, Vrushali H.
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- Polyvinyl trisulfonate ethylamine based solid acid catalyst for the efficient glycosylation of sugars under solvent free conditions
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Heterogeneous Bronsted solid acid catalysts have the potential to decrease the environmental impact related to chemical production. Herein, we have synthesized polyvinyl bound trisulfonate ethylamine chloride (PV-THEAC) and polyvinyl bound disulfonate ethylamine (PV-DSEA) as Bronsted solid acid catalysts which exhibited effective catalytic activity for acid catalyzed glycosylation reactions with sugar derivatives. In particular, 0.3 equiv. of the PV-THEAC catalyst was found to be the most efficient and a reusable catalyst for glycosylation reactions. A high density of the trisulfonic group (-OSO3H) contributed to the excellent catalytic activity during glycosylation. Moreover, glycosylation reactions with d-mannose, d-xylose and d-glucose have been studied with alcohol. Remarkable acceleration of the glycosylation reaction using a glycosyltrichloroacetimidate donor was obtained with the selective production of β-glycoside.
- Chaugule, Avinash A.,Jadhav, Amol R.,Kim, Hern
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p. 104715 - 104724
(2015/12/30)
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- AuCl3- and AuCl3-Phenylacetylene-Catalyzed Glycosylations by Using Glycosyl Trichloroacetimidates
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Glycosylations of armed and disarmed trichloroacetimidate-based glycosyl donors were carried out by using the AuCl3-phenylacetylene relay catalyst system. The effectiveness of this catalytic system was also compared with that of using AuCl3 alone as a catalyst. Glycosylations with these catalysts proceeded efficiently at room temperature within 5-45 min. Excellent diastereoselectivity was obtained for the glycosylation of 2-O-acetyl-protected disarmed glycosyl donors, whereas armed glycosyl trichloroacetimidates gave rise to a mixture of anomeric glycosides. Acid-sensitive nucleophiles such as Fmoc-serine tert-butyl ester or Fmoc-threonine tert-butyl ester successfully underwent the glycosylations, albeit in moderate yields, under mild conditions at room temperature. We have reported a convenient room temperature protocol that employs AuCl3 and phenylacetylene as a catalyst system to carry out the glycosylation of glycosyl trichloroacetimidates. The effectiveness of this relay catalyst system was also compared with that of using AuCl3 alone to catalyze the glycosylations.
- Roy, Rashmi,Palanivel, Ashok Kumar,Mallick, Asadulla,Vankar, Yashwant D.
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p. 4000 - 4005
(2015/06/30)
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- Carbohydrate-derived iminium salt organocatalysts for the asymmetric epoxidation of alkenes
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A new family of carbohydrate-based dihydroisoquinolinium salts has been prepared and tested for potential as asymmetric catalysts for the epoxidation of unfunctionalized alkene substrates, providing up to 57% ee in the product epoxides.
- Bulman Page, Philip C.,Chan, Yohan,Liddle, John,Elsegood, Mark R.J.
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p. 7283 - 7305
(2017/09/13)
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- Native chemical ligation, thiol-ene click: A methodology for the synthesis of functionalized peptides
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The sequential combination of native chemical ligation and thiol-ene radical chemistry (NCL-TEC) on the resulting cysteine thiol has been investigated as a methodology for rapidly accessing functionalized peptides. Three sequential cycles of native chemical ligation and subsequent thiyl radical reactions (including a free-radical-mediated desulfurization reaction) were carried out on a peptide backbone demonstrating the iterative nature of this process. The versatility of the thiyl radical reaction at cysteine was demonstrated through the introduction of a number of different side chains including an amino acid derivative, a carbohydrate group, and an alkyl azide. Conditions were developed that allowed the sequential NCL-TEC process to proceed in high yield.
- Markey, Lyn,Giordani, Silvia,Scanlan, Eoin M.
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p. 4270 - 4277
(2013/06/27)
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- Thiol-ene click chemistry for the synthesis of highly effective glycosyl sulfonamide carbonic anhydrase inhibitors
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Thiol-ene click chemistry has been applied for obtaining sulfonamide carbonic anhydrase (CA, EC 4.2.1.1) inhibitors incorporating sugar moieties. Most of these new compounds were moderate CA I inhibitors, effective CA II inhibitors, and low nanomolar/subn
- Saada, Mohamed-Chiheb,Ombouma, Joanna,Montero, Jean-Louis,Supuran, Claudiu T.,Winum, Jean-Yves
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supporting information
p. 5699 - 5701
(2013/07/25)
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- Structural Studies of the O-Acetyl-Containing O-Antigen from a Shigella flexneri Serotype 6 Strain and Synthesis of Oligosaccharide Fragments Thereof
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Extensive analysis by NMR spectroscopy of the delipidated lipopolysaccharide of Shigella flexneri serotype 6 strain MDC 2924-71 confirmed the most recently reported structure of the O-antigen repeating unit as {→4)-β-D-GalpA-(1→3)-β-D-GalpNAc-(1→2) -α-L-R
- Chassagne, Pierre,Fontana, Carolina,Guerreiro, Catherine,Gauthier, Charles,Phalipon, Armelle,Widmalm, Goeran,Mulard, Laurence A.
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p. 4085 - 4106
(2013/07/26)
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- Solvent-free mechanochemical glycosylation in ball mill
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Starting from acetobromosugars and an alcohol (alkyl/substituted alkyl/akenyl/alkynyl/glyceryl/cyclohexyl/steryl) various O-glycosides have been prepared mechanochemically under solvent-free conditions employing a planetary ball mill in the presence of metal carbonates (environmentally benign or otherwise) as promoters. The method was proven to be mild and efficient and applicable on preparative scale for the synthesis of various mono- and disaccharide glycosides. 4-Pentenyl glycoside so produced could, in four successive reactions in the same pot, be converted in high isolated yields into triazole-substituted pentyl glycoside that can find application in the area of medicinal chemistry.
- Tyagi, Mohit,Khurana, Darpan,Ravindranathan Kartha
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- Stereoselective dihydroxylation reaction of alkenyl β- D -hexopyranosides: A methodology for the synthesis of glycosylglycerol derivatives and 1-O-Acyl-3-O-β- D -glycosyl-sn-glycerol analogues
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A variety of new glycosylglycerol derivatives have been prepared by stereoselective dihydroxylation of a range of alkenyl β-D-hexopyanosides under Donohoe's conditions. We have studied the relationship between the diastereoisomeric excess and the structural features of the precursor (sugar and alkenyl moieties). The stereochemical yields demonstrated that the presence of a hydrogen-bond donor group (OH, NHAc) at the 2-position of the sugar moiety is required to obtain high levels of stereofacial discrimination. New 1-O-acyl-3-O-β-D-glycosyl-sn-glycerol analogues were obtained by functionalisation of the primary hydroxy group with a fatty acid. Preliminary cytotoxic activity assays of both glycosylglycerol and glycoglycerolipid analogues are also presented. An efficient asymmetric dihydroxylation reaction of alkenyl β-D-hexopyranoside derivatives is described. New glycosylglycerol and glycoglycerolipid analogues have been synthesised by this methodology. Preliminary cytotoxic activity assays are presented. Copyright
- Vega-Perez, Jose M.,Palo-Nieto, Carlos,Perinan, Ignacio,Vega-Holm, Margarita,Calderon-Montano, Jose M.,Lopez-Lazaro, Miguel,Iglesias-Guerra, Fernando
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experimental part
p. 1237 - 1252
(2012/04/10)
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- Saccharide-modified nanodiamond conjugates for the efficient detection and removal of pathogenic bacteria
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The detection and removal of bacteria, such as E. coli in aqueous environments by using safe and readily available means is of high importance. Here we report on the synthesis of nanodiamonds (ND) covalently modified with specific carbohydrates (glyco-ND) for the precipitation of type 1 fimbriated uropathogenic E. coli in solution by mechanically stable agglutination. The surface of the diamond nanoparticles was modified by using a Diels-Alder reaction followed by the covalent grafting of the respective glycosides. The resulting glyco-ND samples are fully dispersible in aqueous media and show a surface loading of typically 0.1 mmol g-1. To probe the adhesive properties of various ND samples we have developed a new sandwich assay employing layers of two bacterial strains in an array format. Agglutination experiments in solution were used to distinguish unspecific interactions of glyco-ND with bacteria from specific ones. Two types of precipitates in solution were observed and characterized in detail by light and electron microscopy. Only by specific interactions mechanically stable agglutinates were formed. Bacteria could be removed from water by filtration of these stable agglutinates through 10 μm pore-size filters and the ND conjugate could eventually be recovered by addition of the appropriate carbohydrate. The application of glycosylated ND allows versatile and facile detection of bacteria and their efficient removal by using an environmentally and biomedically benign material. Copyright
- Hartmann, Mirja,Betz, Patrick,Sun, Yuchen,Gorb, Stanislav N.,Lindhorst, Thisbe K.,Krueger, Anke
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supporting information; experimental part
p. 6485 - 6492
(2012/06/16)
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- Rapid-throughput competitive colorimetric assay based on monosaccharide-capped gold nanoparticles for detecting lectin-protein interactions
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Identification of protein binding partners is one of key challenges in proteomics. A rapid-throughput competitive colorimetric assay is presented that uses gold nanoparticles capped by sugars such as mannopyranoside (Man-GNPs), N-acetylglucosamine (GlcNAc-GNPs), glucose (Glc-GNPs), or N-acetylgalactosamine (GalNAc-GNPs). The assay expediently detects protein-protein interactions in solution, particularly protein-lectin interactions. The competitive assays were conducted in microtiter plates; ten proteins (two glycoproteins and eight lectins) and three sugar-binding lectins (concanavalin A (ConA), wheat germ agglutinin (WGA), and Ricinus communis agglutinin (RCA120)) were combinatorially arranged in a 30-well plate, and constant concentrations of the monosaccharide-capped GNPs (sugar-GNPs) were added to each well. If interactions occurred between the proteins, the sugar-GNPs retained their burgundy color. If no interactions occurred between the proteins, the sugar-GNPs were agglomerated by the corresponding binding lectin, thus producing a blue color. Several new binding pairs were identified for the first time by using this assay, and the binding constants and stoichiometric ratios were determined on the basis of the wavelength shifts. The results were further verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and fluorescence resonance energy transfer (FRET) spectroscopy. The assay is very sensitive, requiring only nanomolar protein concentrations.
- Tsai, Charng-Sheng,Chen, Chao-Tsen
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p. 314 - 322
(2014/01/17)
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- Synthesis of trisaccharides by hetero-diels-alder welding of two monosaccharide units
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A new strategy for the synthesis of di- and trisaccharides based on the de novo synthesis of the linking saccharide unit is presented. In this strategy, functionalized monosaccharide building blocks already incorporating the glycosidic linkages are welded together using a metal-catalyzed hetero-Diels-Alder (HDA) reaction to generate a new monosaccharide unit between them. The highest yields and selectivities in the HDA reaction were obtained by using chiral Schiff base chromium complexes. Disaccharide products were accessible by reaction of Danishefsky's diene with acetyl- and benzyl-protected galactoside aldehydes. For the synthesis of trisaccharide products, acetyl-protected glucose or galactose-derived dienes were fused with monosaccharide-derived aldehydes using chromium catalysts for the HDA reaction. The desired trisaccharide products were obtained in moderate to good yields with excellent stereoselectivity. The central pyranulose-ring generated in the process possessed an L-cis-enulose configuration according to NMR spectroscopy and modeling studies. 1 + 1 equals 3! The hetero-Diels-Alder union of two functionalized monosaccharide building blocks - one bearing an aldehyde and the other a readily accessible diene moiety - affords functionalized trisaccharide structures in moderate to good yields and excellent stereoselectivities when β-anomers of the aldehydes are used. Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
- Himanen, Jatta A.,Pihko, Petri M.
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experimental part
p. 3765 - 3780
(2012/09/25)
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- Structurally diverse disaccharide analogs of antifreeze glycoproteins and their ability to inhibit ice recrystallization
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The β-D-galactosyl-(1,3)-α-N-acetyl-D-galactosamine disaccharide is present in antifreeze glycoproteins (AFGPs). Analogs of this disaccharide including the β-linked (1,3)-, (1,4)-, and (1,6)-galactosyl-N-acetyl galactosamine and the β-(1,3)-galactosyl-galactoside were synthesized and evaluated for ice recrystallization inhibition (IRI) activity. The results from this study demonstrate that the b-linked-(1,4) disaccharide exhibits more potent IRI activity than the native b-linked-(1,3) disaccharide. The C2 N-acetyl group of the disaccharide does not affect IRI activity but in monosaccharides, the presence of the C2 N-acetyl group decreases IRI activity. The current study will facilitate the design of potent small-molecule ice recrystallization inhibitors.
- Balcerzak, Anna K.,Ferreira, Sandra S.,Trant, John F.,Ben, Robert N.
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supporting information; experimental part
p. 1719 - 1721
(2012/04/04)
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- Rapid-throughput competitive colorimetric assay based on monosaccharide-capped gold nanoparticles for detecting lectin-protein interactions
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Identification of protein binding partners is one of key challenges in proteomics. A rapid-throughput competitive colorimetric assay is presented that uses gold nanoparticles capped by sugars such as mannopyranoside (Man-GNPs), N-acetylglucosamine (GlcNAc-GNPs), glucose (Glc-GNPs), or N-acetylgalactosamine (GalNAc-GNPs). The assay expediently detects protein- protein interactions in solution, particularly protein-lectin interactions. The competitive assays were conducted in microtiter plates; ten proteins (two glycoproteins and eight lectins) and three sugar-binding lectins (concanavalin A (ConA), wheat germ agglutinin (WGA), and Ricinus communis agglutinin (RCA120)) were combinatorially arranged in a 30-well plate, and constant concentrations of the monosaccharide-capped GNPs (sugar-GNPs) were added to each well. If interactions occurred between the proteins, the sugar-GNPs retained their burgundy color. If no interactions occurred between the proteins, the sugar-GNPs were agglomerated by the corresponding binding lectin, thus producing a blue color. Several new binding pairs were identified for the first time by using this assay, and the binding constants and stoichiometric ratios were determined on the basis of the wavelength shifts. The results were further verified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and fluorescence resonance energy transfer (FRET) spectroscopy. The assay is very sensitive, requiring only nanomolar protein concentrations.
- Tsai, Charng-Sheng,Chen, Chao-Tsen
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p. 314 - 322
(2013/01/13)
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- OLEFIN METATHESIS REACTIONS OF AMINO ACIDS, PEPTIDES AND PROTEINS CONTAINING ALLYL SULFIDE GROUPS
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A method for the modification of an amino acid, protein or peptide is disclosed. The method comprises reacting a carbon-carbon double bond-containing compound with an amino acid, a protein or a peptide containing an allyl sulfide group in the presence of a catalyst which promotes olefin metathesis, to form a modified amino acid, protein or peptide. Preferred carbon-carbon double bond-containing compounds include carbohydrates.
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Page/Page column 7
(2012/07/27)
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- COMPOUND RETAINED IN TUMOR
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A novel compound which specifically resides in a tumor, a method for allowing it to reside in a tumor, and a method for detecting, diagnosing, and treating tumor with use thereof are provided. The present invention relates to a compound represented by chemical formula (I) wherein R is an anionic group binding to hydrogen, R1 is OH, OCOH, OCO(CH2)hCH3, or an acting group, h being an integer of 0 or more, R2 is H, OH, OCOH, OCO(CH2)iCH3, or an acting group, i being an integer of 0 or more, R3 is OH, SO3H, or an acting group, R4 is OH, SO3H, or an acting group, and R5 is OH, SO3H, or an acting group, at least one of R1, R2, R3, R4, and R5 containing an acting group, or pharmaceutically acceptable salts thereof.
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Page/Page column 48
(2011/12/03)
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- Synthesis of galactofuranose-based acceptor substrates for the study of the carbohydrate polymerase GlfT2
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Despite the prevalence and importance of carbohydrate polymers, the molecular details of their biosynthesis remain elusive. Many enzymes responsible for the synthesis of carbohydrate polymers require a 'primer' or 'initiator' carbohydrate sequence. One example of such an enzyme is the mycobacterial galactofuranosyltransferase GlfT2 (Rv3808c), which generates an essential cell wall building block. We recently demonstrated that recombinant GlfT2 is capable of producing a polymer composed of alternating β-(1,5) and β-(1,6)-linked galactofuranose (Galf) residues. Intriguingly, the length of the polymers produced from a synthetic glycosyl acceptor is consistent with those found in the cell wall. To probe the mechanism by which polymer length is controlled, a collection of initiator substrates has been assembled. The central feature of the synthetic route is a ruthenium-catalyzed cross-metathesis as the penultimate transformation. Access to synthetic substrates has led us to postulate a new mechanism for length control in this template-independent polymerization. Moreover, our investigations indicate that lipids possessing but a single galactofuranose residue can act as substrates for GlfT2.
- Splain, Rebecca A.,Kiessling, Laura L.
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experimental part
p. 3753 - 3759
(2010/08/03)
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- Alkenyl β-d-galactopyranoside derivatives as efficient chiral templates in stereoselective cyclopropanation and epoxidation reactions
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The synthesis of a wide range of alkenyl 4,6-O-(S)-benzylidene-β-d-galactopyranosides is described. The cyclopropanation and epoxidation reactions of these compounds were developed. Cyclopropanation reactions took place with high stereoselectivity giving diastereomeric excesses of up to 100%. As a part of our aim in studying hydroxyl-directed reactions, their epoxidation with m-CPBA was carried out. High diastereomeric excesses (80-100%) were obtained when the hydroxyl group at C-2 of the auxiliary was unprotected. The β-d-galactopyranoside moiety constitutes as an interesting auxiliary, due to its efficient chirality transfer capability as well as providing a way to obtain a variety of glycolipid derivatives.
- Vega-Perez, Jose M.,Perinan, Ignacio,Palo-Nieto, Carlos,Vega-Holm, Margarita,Iglesias-Guerra, Fernando
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experimental part
p. 81 - 95
(2010/04/06)
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- Olefin cross-metathesis on proteins: Investigation of allylic chalcogen effects and guiding principles in metathesis partner selection
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Olefin metathesis has recently emerged as a viable reaction for chemical protein modification. The scope and limitations of olefin metathesis in bioconjugation, however, remain unclear. Herein we report an assessment of various factors that contribute to productive cross-metathesis on protein substrates. Sterics, substrate scope, and linker selection are all considered. It was discovered during this investigation that allyl chalcogenides generally enhance the rate of alkene metathesis reactions. Allyl selenides were found to be exceptionally reactive olefin metathesis substrates, enabling a broad range of protein modifications not previously possible. The principles considered in this report are important not only for expanding the repertoire of bioconjugation but also for the application of olefin metathesis in general synthetic endeavors.
- Lin, Yuya A.,Chalker, Justin M.,Davis, Benjamin G.
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supporting information; experimental part
p. 16805 - 16811
(2011/02/17)
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- Variations on the SnCl4 and CF3CO2Ag-promoted glycosidation of sugar acetates: a direct, versatile and apparently simple method with either α or β stereocontrol
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Glycosidation of sugar peracetates (d-gluco, d-galacto) with SnCl4 and CF3CO2Ag led to either 1,2-cis-, or 1,2-trans-glycosides, depending primarily on the alcohols used. In particular, 1,2-trans-glycosides, expected from acyl-protected glycosyl donors, were formed in high yields with alcohols sharing specific features such as bulkiness, presence of electron-withdrawing groups or polyethoxy motifs. In contrast, simple alcohols afforded ～1:1 mixtures of 2,3,4,6-tetra-O-acetyl, and 3,4,6-tri-O-acetyl 1,2-cis-glycosides due to anomerization and/or acid-catalyzed fragmentation of 1,2-orthoester intermediates. After reacetylation or deacetylation, acetylated or fully deprotected 1,2-cis-glycosides (α-d-gluco, α-d-galacto) were obtained in ～90% yields by a simple and direct method.
- Xue, Jia Lu,Cecioni, Samy,He, Li,Vidal, Sébastien,Praly, Jean-Pierre
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experimental part
p. 1646 - 1653
(2009/12/24)
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- Sulfonated sugar compounds, pharmaceutical compositions which contain the same, and methods of treating tumors with the same
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Sulfoquinovosylacyl propanediol compounds represented by formula (I): wherein R1 is an acyl residue of a fatty acid, Y is a number of 1, 2 or 3, and M represents a cation having a positive charge equal to Y and pharmaceutically acceptable salts
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Page/Page column 20-21
(2009/09/05)
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- Hydration index-a better parameter for explaining small molecule hydration in inhibition of ice recrystallization
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Several simple mono- and disaccharides have been assessed for their ability to inhibit ice recrystallization. Two carbohydrates were found to be effective recrystallization inhibitors. D-Galactose (1) was the best monosaccharide and D-melibiose (5) was the most active disaccharide. The ability of each carbohydrate to inhibit ice growth was correlated to its respective hydration number reported in the literature. A hydration number reflects the number of tightly bound water molecules to the carbohydrate and is a function of carbohydrate stereochemistry. It was discovered that using the absolute hydration number of a carbohydrate does not allow one to accurately predict its ability to inhibit ice recrystallization. Consequently, we have defined a hydration index in which the hydration number is divided by the molar volume of the carbohydrate. This new parameter not only takes into account the number of water molecules tightly bound to a carbohydrate but also the size or volume of a particular solute and ultimately the concentration of hydrated water molecules. The hydration index of both mono- and disaccharides correlates well with experimentally measured Rl activity. C-Linked derivatives of the monosaccharides appear to have Rl activity comparable to that of their O-linked saccharides but a more thorough investigation is required. The relationship between carbohydrate concentration and Rl activity was shown to be noncolligative and a 0.022 M solution of D-galactose (1) and C-linked galactose derivative (10) inhibited recrystallization as well as a 3% DMSO solution. The carbohydrates examined in this study did not possess any thermal hysteresis activity (selective depression of freezing point relative to melting point) or dynamic ice shaping. As such, we propose that they are inhibiting recrystallization at the interface between bulk water and the quasi liquid layer (a semiordered interface between ice and bulk water) by disrupting the preordering of water.
- Tam, Roger Y.,Ferreira, Sandra S.,Czechura, Pawel,Ben, Robert N.,Chaytor, Jennifer L.
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supporting information; experimental part
p. 17494 - 17501
(2009/07/25)
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- Allyl sulfides are privileged substrates in aqueous cross-metathesis: Application to site-selective protein modification
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Allyl sulfides undergo efficient cross-metathesis in aqueous media with Hoveyda-Grubbs second generation catalyst 1. The high reactivity of allyl sulfides in cross-metathesis was exploited in the first examples of cross-metathesis on a protein surface. S-Allylcysteine was incorporated chemically into the protein, providing the requisite allyl sulfide handle. Preliminary efforts to genetically incorporate S-allylcysteine into proteins are also reported. Copyright
- Lin, Yuya A.,Chalker, Justin M.,Floyd, Nicola,Bernardes, Goncalo J. L.,Davis, Benjamin G.
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supporting information; experimental part
p. 9642 - 9643
(2009/02/04)
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- Synthetic routes to three novel scaffolds for potential glycosidase inhibitors
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Efficient syntheses of three novel scaffolds for potential β-glycosidase inhibitors were developed: The first consists of a 2,7-dioxabicyclo[2.2.1]heptane derivative, which was prepared by an intramolecular ketalisation. The second scaffold consists of a
- Rommel, Michael,Ernst, Alexander,Koert, Ulrich
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p. 4408 - 4430
(2008/09/17)
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- Synthesis of novel bicyclic ketals of galacturonic acid as potential glycosidase inhibitors
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A synthesis of novel bicyclic ketals of galacturonic acid is described. The key cyclisation step was realised under acidic anhydrous conditions in very good yield. X-ray crystal structure analysis determined the correct regio- and stereochemistry. Georg T
- Rommel, Michael,Ernst, Alexander,Harms, Klaus,Koert, Ulrich
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p. 1067 - 1070
(2007/10/03)
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- Simple preparation of phenylpropenoid β-D-glucopyranoside congeners by Mizoroki-Heck type reaction using organoboron reagents
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Palladium(II)-catalyzed carbon-carbon bond formation between allyl 2,3,4,6-tetra-O-acetyl-β-d-glucopyranoside (3) and arylboronic acid congeners gave the corresponding cinnamyl 2,3,4,6-tetra-O-acetyl- β-d-glucopyranosides (4a-m) in good yield. Among them, coupling products 4a-m were converted to not only the naturally occurring phenylpropenoid β-d-glucopyranoside analogues (1a-e) but also the unnaturally ones (1f-m).
- Kishida, Masashi,Akita, Hiroyuki
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p. 10559 - 10568
(2007/10/03)
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- InCl3.3H2O: An efficient Lewis acid catalyst for stereoselective O-glycosidation reactions of per-O-acetylglycopyranosyl trichloroacetimidates
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InCl3.3H2O catalysed highly stereoselective O-glycosidation of per-O-acetylglycopyranosyl trichloroacetimidates with a variety of aliphatic alcohols in dichloromethane at room temperature furnishes the corresponding glycosides in very good yields with excellent 1,2-trans stereoselectivity.
- Ghosh, Rina,Chakraborty, Arijit,Maiti, Dilip Kumar
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p. 602 - 604
(2007/10/03)
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- Synthesis of ω-unsaturated O-protected glucosides as precursors for unsaturated neutral bolaforms
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The Lewis acid catalyzed glycosylation reaction of βperacetylated sugar derivative (glucose) with terminally unsaturated C3-C11-alkenols is used in a synthesis of some C3-C11alkenyl glucopyranosides as precursors for unsaturated neutral bolaforms. The process occurs under the influence of tin(IV) chloride.
- Konstantinovi?,Predojevi?,Gojkovi?,Pavlovi?
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p. 666 - 669
(2007/10/03)
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- Galectin recognized photosensitizers for photodynamic therapy
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Purpurin-carbohydrate conjugates and their method of preparation and use for treatment of cancer cells. The conjugates have the general formula: where R6 and R7 taken together are -NR11 or are independently -OR11 where at least one R11 is preferably a mono or polysaccharide moiety and R1 - R8 are various groups formed from carbon and hydrogen and optionally oxygen and nitrogen where R3 and R4 may together form a covalent bond.
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- InCl3 - An efficient Lewis acid catalyst for stereoselective O-glycosidation reactions
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InCl3 catalysed O-glycosidation of acetobromoglucose with different primary alcohols in dichloromethane furnish mostly the corresponding β-D-glucopyranosides in very high yields and stereoselectivity. 3,4,6-tri-O-acetyl-2-bromo-2-deoxy-α-D-mann
- Ghosh, Rina,Chakraborty, Arijit,Maiti, Dilip K.,Maiti, Swaraj B.
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p. 583 - 585
(2007/10/03)
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- Synthesis of glycosides via indium(III) chloride mediated activation of glycosyl halide in neutral condition
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Various glycosides and disaccharides were synthesized through coupling of glycosyl bromides with acceptors in presence of indium chloride as a promoter. Glycosidation reactions proceeded with high stereoselectivity.
- Mukherjee, Debaraj,Kumar Ray, Pradip,Sankar Chowdhury, Uday
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p. 7701 - 7704
(2007/10/03)
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- A practical synthetic method for α- and β-glycosyloxyacetic acids
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Dihydroxylation of allyl 2,3,4-tri-O-benzyl-6-O-tritylglycosides provides diols, the anomers of which can easily be separated by column chromatography in a practical scale. These anomers can be cleanly transformed into α- and β-glycosyloxyacetic acids, respectively, via oxidative cleavage of the diol followed by oxidation.
- Mandai, Tadakatsu,Okumoto, Hiroshi,Oshitari, Tetsuta,Nakanishi, Katsuyoshi,Mikuni, Katsuhiko,Hara, Ko-Ji,Hara, Ko-Zo
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p. 129 - 132
(2007/10/03)
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- Efficient synthesis of the anticancer drug etoposide 4′-phosphate: Use of benzylic ether-protecting groups on the carbohydrate segment
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The prodrug etoposide phosphate 2 is synthesized efficiently in three steps in 54.6% overall yield from 4′-demethylepipodophyllotoxin 3. The strategy pursued in the synthesis of 2 places the phosphate on 3 prior to coupling with the sugar and employs benzyl ether-protecting groups on both the phosphate and the sugar, allowing easy removal in one step. The importance of solvent, steric effects, and electronic effects in the coupling reaction is demonstrated. Two features of the synthesis are an unusual thermal anomerization of the carbohydrate component 5a and completely diastereoselective, one-pot crystallization of the coupled product 6a-β. The process has been demonstrated on multi-kilogram scale.
- Silverberg, Lee J.,Dillon, John L.,Vemishetti, Purushotham,Sleezer, Paul D.,Discordia, Robert P.,Hartung, Kerry B.,Gao, Qi
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