- β-D-glucosyl and α-D-galactosyl yariv reagents: Syntheses from p-nitrophenyl-D-glycosides by transfer reduction using ammonium formate
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Yariv β-D-glucosyl (4a) and Yariv α-D-galactosyl (4b) reagents are multivalent phenylglycosides. The β-D-glucosyl reagent is considered diagnostic for arabinogalactan proteins (AGPs) to which it can reversibly bind, stain, and precipitate. The α-D-galacto
- Basile, Dominick V.,Ganjian, Iraj
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- Self-assembling structures of long-chain phenyl glucoside influenced by the introduction of double bonds
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Four long-chain phenyl glucoside amphiphiles possessing a saturated or unsaturated long alkyl chain group as the self-assembling unit of a highly organized molecular architecture were synthesized. Their self-assembling properties were investigated by EF-T
- Jung, Jong Hwa,John, George,Yoshida, Kaname,Shimizu, Toshimi
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- Molecularly Imprinted Synthetic Glucosidase for the Hydrolysis of Cellulose in Aqueous and Nonaqueous Solutions
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Molecular imprinting is a powerful and yet simple method to create multifunctional binding sites within a cross-linked polymer network. We report a new class of synthetic glucosidase prepared through molecular imprinting and postfunctionalization of cross-linked surfactant micelles. These catalysts are protein-sized water-soluble nanoparticles that can be modified in multiple ways. As their natural counterparts, they bind a glucose-containing oligo- or polysaccharide. They contain acidic groups near the glycosidic bond to be cleaved, with the number and distance of the acid groups tuned systematically. Hydrolysis of cellulose in a key step in biomass conversion but is hampered by the incalcitrance of the highly crystalline cellulose fibers. The synthetic glucosidases are shown to hydrolyze cellobiose and cellulose under a variety of conditions. The best catalyst, with a biomimetic double acid catalytic motif, can hydrolyze cellulose with one-fifth of the activity of commercial cellulases in aqueous buffer. As a highly cross-linked polymeric nanoparticle, the synthetic catalyst is stable at elevated temperatures in both aqueous and nonaqueous solvents. In a polar aprotic solvent/ionic liquid mixture, it hydrolyzes cellulose several times faster than commercial cellulases in aqueous buffer. When deposited on magnetic nanoparticles, it retains 75% of its activity after 10 cycles of usage.
- Li, Xiaowei,Zangiabadi, Milad,Zhao, Yan
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- Direct sol-gel replication of the self-assembled nanostructure modified with H-bond functionalities
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The glucopyranoside-based amphiphile 1 formed nanofiber structures with 25-100 nm of diameters and several micrometer lengths in the presence of aminophenyl glucopyranoside 2, and their self-assembled nanostructures were successfully replicated into the s
- Jung, Jong Hwa,Shimizu, Toshimi
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- Enzymatic Synthesis of a Series of Thioglycosides: Analogs of Arbutin with Efficient Antipigmentation Properties
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Arbutin, a natural glycoside, is well known as a commercial tyrosinase inhibitor, and thus, to prevent pigmentary disorders of skin. In fact, tyrosinase is involved in the biosynthesis of melanin, the skin main pigment. However, arbutin is subject to hydr
- Daniellou, Richard,Didak, Blanka,Guillotin, Laure,Lafite, Pierre,Landemarre, Ludovic,Lemiègre, Lo?c,Peyrot, Cédric
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p. 3812 - 3818
(2021/08/24)
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- An Improved Protocol for the Synthesis and Purification of Yariv Reagents
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Yariv reagents are glycoconjugate tris-azo dyes widely used in plant biology. These reagents are synthesized by diazo coupling between phloroglucinol and a para-diazophenyl glycoside. Despite their synthetic accessibility, well-defined protocols for obtai
- Hoshing, Raghuraj,Saladino, Michael,Kuhn, Helene,Caianiello, David,Lusi, Robert F.,Basu, Amit
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p. 16236 - 16242
(2020/11/20)
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- Rapid phenolic O-glycosylation of small molecules and complex unprotected peptides in aqueous solvent
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Glycosylated natural products and synthetic glycopeptides represent a significant and growing source of biochemical probes and therapeutic agents. However, methods that enable the aqueous glycosylation of endogenous amino acid functionality in peptides without the use of protecting groups are scarce. Here, we report a transformation that facilitates the efficient aqueous O-glycosylation of phenolic functionality in a wide range of small molecules, unprotected tyrosine, and tyrosine residues embedded within a range of complex, fully unprotected peptides. The transformation, which uses glycosyl fluoride donors and is promoted by Ca(OH)2, proceeds rapidly at room temperature in water, with good yields and selective formation of unique anomeric products depending on the stereochemistry of the glycosyl donor. High functional group tolerance is observed, and the phenol glycosylation occurs selectively in the presence of virtually all side chains of the proteinogenic amino acids with the singular exception of Cys. This method offers a highly selective, efficient, and operationally simple approach for the protecting-group-free synthesis of O-aryl glycosides and Tyr-O-glycosylated peptides in water.
- Wadzinski, Tyler J.,Steinauer, Angela,Hie, Liana,Pelletier, Guillaume,Schepartz, Alanna,Miller, Scott J.
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p. 644 - 652
(2018/05/04)
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- Iron and palladium(II) phthalocyanines as recyclable catalysts for reduction of nitroarenes
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Iron(II) and palladium(II) phthalocyanines have been established as recyclable heterogeneous catalysts for the reduction of aromatic nitro compounds to corresponding amines using diphenylsilane/sodium borohydride as hydrogen sources in ethanol. Various reducible functional groups, such as acetyl, ester, cyano, amide, sulphonamide and carboxylic acid etc. were well tolerated, and the methods were applicable up to gram scale. Mechanistic studies showed that reduction of nitro group proceed through direct (nitroso) pathway and possibly iron or palladium phthalocyanines activates nitro group for reduction. FePc and PdPc also catalyzed the generation of hydrogen from the combination of diphenylsilane/sodium borohydride and ethanol.
- Verma, Praveen Kumar,Bala, Manju,Thakur, Kavita,Sharma, Upendra,Kumar, Neeraj,Singh, Bikram
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p. 1258 - 1267
(2014/07/21)
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- Carbohydrate coatings via aryldiazonium chemistry for surface biomimicry
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Carbohydrates are extremely important biomolecules and their immobilization onto solid surfaces is of interest for the development of new biomimetic materials and of new methods for understanding processes in glycobiology. We have developed an efficient surface modification methodology for the functionalization of a range of materials with biologically active carbohydrates based on aryldiazonium chemistry. We describe the synthesis and characterization of carbohydrate reagents, which were subsequently employed for the one-step, solution-based modification of carbon, metals, and alloys with monosaccharides. We used a combination of spectroscopic and nanogravimetric methods to characterize the structure of the carbohydrate layers; we report an average surface coverage of 7.8 × 10-10 mol cm-2 under our experimental conditions. Concanavalin A, a mannose-binding lectin, and Peanut Agglutinin, a galactose-binding lectin, were found to bind from solution to their respective monosaccharide binding partners immobilized at the surface. This result suggests that the spontaneous chemisorption of aryldiazonium monosaccharide precursors leads to the formation of monosaccharide layers that retain the biological recognition specificity of the parent carbohydrate molecule. Finally, we carried out measurements using fluorescently labeled Bovine Serum Albumin (BSA) and found that these carbohydrate coatings reduce unspecific adsorption of this protein at carbon surfaces. These results suggest that aryldiazonium-derived carbohydrate coatings may offer a promising strategy for preventing undesirable protein accumulation onto surfaces.
- Jayasundara, Dilushan R.,Duff, Thomas,Angione, M. Daniela,Bourke, Jean,Murphy, Deirdre M.,Scanlan, Eoin M.,Colavita, Paula E.
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p. 4122 - 4128
(2013/11/19)
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- A novel d-glucose derivative radiolabeled with technetium-99m: Synthesis, biodistribution studies and scintigraphic images in an experimental model of Ehrlich tumor
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A d-glucose-MAG3 derivative was successfully synthesized and radiolabeled in high labeling yield. Biodistribution studies and scintigraphic images in Ehrlich tumor-bearing mice were performed. This compound showed high accumulation in tumor tis
- de Barros, André Luís Branco,Cardoso, Valbert Nascimento,Mota, Luciene das Gra?as,Leite, Elaine Amaral,de Oliveira, M?nica Cristina,Alves, Ricardo José
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p. 2478 - 2480
(2010/07/06)
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- Synthesis and biodistribution studies of carbohydrate derivatives radiolabeled with technetium-99m
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Three carbohydrate derivatives, MAG3-Gl, MAG3-Ga, MAG3-NG, were synthesized and radiolabeled in high yields. These substances were injected in health Swiss mice and their biodistribution were evaluated. Among them, 99
- de Barros, Andre Luis Branco,Cardoso, Valbert Nascimento,Mota, Luciene das Gracas,Alves, Ricardo Jose
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scheme or table
p. 315 - 317
(2010/04/05)
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- Self-assembling structures of long-chain sugar-based amphiphiles influenced by the introduction of double bonds
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Nine phenyl glucoside or galactoside amphiphiles possessing a saturated or unsaturated long alkyl-chain group as the self-assembling unit of a highly organized molecular architecture were synthesized. Their self-assembly properties were investigated by using energy-filtering TEM (EF-TEM), SEM, CD, XRD, and FT-IR techniques. Compound 2, possessing one cis double bond in the lipophilic portion, exhibited twisted helical fibers, which formed a bilayered structure with a 3.59 nm period, while 3 exhibited helical ribbons and left-handed nanotubu-lar structures with 150-200 nm inner diameters and a wall thickness of approximately 20 nm. Very interestingly, 4, possessing three cis double bonds, exhibited a nanotubular structure with an inner diameter of approximately 70 nm and a d spacing value of 4.62 nm. On the other hand, 7, possessing two trans double bonds in the lipophilic region, exhibited crystal- or plate-like structures, which formed a bilayer structure with a d spacing value of 3.93 nm. These results indicate that the self-assembly properties are strongly dependent on the type of double bond. Furthermore, 8 and 9, with the galactopyr anose moiety, revealed helical ribbon and well-defined double helical fiber structures, respectively. These findings support the view that the orientation of the intermolecular hydrogen-bonding interaction between the sugar moieties plays a critical role in producing the nanotubular structures. According to CD and powder XRD experiments, the relatively strong intermolecular hydrogen-bonding interaction of the glucopyranoside moiety in 3 and 4 provided a highly ordered chiral packing structure. Even though these compounds formed a weak hydrophobic interaction between lipophilic groups, it led to the formation of the nanotubular structure.
- Jung, Jong Hwa,Do, Youngkyu,Lee, Young-A.,Shimizu, Toshimi
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p. 5538 - 5544
(2007/10/03)
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- Sugar-derived gellant for hydrogel formation
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A gelatinizer having gel-forming capability in both organic solvents and water, is provided. This invention is a hydrogelatinizer represented by: (where, A is a sugar residue, and R is an alkyl group).
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Page/Page column 2
(2008/06/13)
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- Solid-phase oligosaccharide and glycopeptide synthesis using glycosynthases
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Enzymatic approaches for the preparation of oligosaccharides are interesting alternatives to traditional chemical synthesis, the main advantage being the regio- and stereoselectivity offered without the need for protecting groups. The use of solid-phase techniques offers easy workup procedures and the prospect of automatability. Here, we report the first application of glycosynthases to solid-phase oligosaccharide synthesis by use of the 51 kDa serine and glycine mutants of Agrobacterium sp. β-glucosidase, Abg E358S and E358G. Acceptors were linked to PEGA resin through a backbone amide linker (BAL), and using these mutated enzymes, a galactose moiety was transferred from a donor sugar, α-D-galactosyl fluoride, with high efficiency (>90%) together with excellent recovery of material. Furthermore, it was demonstrated that a resin-bound model glycopeptide was also an acceptor for the glycosynthase.
- Tolborg, Jakob F.,Petersen, Lars,Jensen, Knud J.,Mayer, Christoph,Jakeman, David L.,Warren, R. Antony J.,Withers, Stephen G.
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p. 4143 - 4149
(2007/10/03)
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- Spectral characterization of self-assemblies of aldopyranoside amphiphilic gelators: What is the essential structural difference between simple amphiphiles and bolaamphiphiles?
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An aldopyranoside-based gelators (dodecanoyl-p-aminophenyl-β-D-aldopyranoside)s and [1,12-dodecanedicarboxylic-bis(p-aminophenyl-β-D-aldopyranoside)]s 1-4 were synthesized, and their gelation ability was evaluated in organic solvents and water. Simple ald
- Jung, Jong Hwa,Shinkai, Seiji,Shimizu, Toshimi
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p. 2684 - 2690
(2007/10/03)
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- New organogelators bearing both sugar and cholesterol units: An approach toward molecular design of universal gelators
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The gelators of organic solvents are classified into two categories on the basis of their basic intermolecular forces: hydrogen-bonded or nonhydrogen-bonded. To utilize these two interactions cooperatively for organogel formation we newly synthesized seven gelators (1-7) and two reference compounds (8 and 9) which have both a cholesterol moiety and a saccharide moiety within one molecule. The solubility of 1-7 changed drastically from totally insoluble one to very soluble one depending on the saccharide absolute configuration. In general, the gelator became very insoluble when it includes many equatorial OH groups, whereas it became very soluble when it includes many axial OH groups. Gelators 2 and 5 bearing two equatorial OH groups and one axial OH group acted as good gelators and in several cases the sol-gel phase-transition temperatures (measured in a sealed tube) were higher than the boiling points. The SEM observations of the xerogels established that the stable gels contain the entangled fibrous network. These results indicate that a very stable organogel can be designed by a cooperative coagulative effect of a cholesterol-cholesterol interaction and a saccharide-saccharide interaction.
- Amaike,Kobayashi,Shinkai
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p. 2553 - 2558
(2007/10/03)
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- Incorporation of carbohydrates and peptides into large triazine-based screening libraries using automated parallel synthesis
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A procedure for the sequential, selective derivatization of cyanuric chloride that allows for the incorporation of carbohydrates and peptides has been elucidated. As a result, large combinatorial arrays of individual derivatives, over 40,000 in all, have
- Gustafson, Gary R.,Baldino, Carmen M.,O'Donnell, Mary-Margaret E.,Sheldon, Adrian,Tarsa, Robert J.,Verni, Christopher J.,Coffen, David L.
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p. 4051 - 4065
(2007/10/03)
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- Syntheses and Transformations of Glycohydrolase Substrates into Protein Conjugates Based on Michael Additions
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The glycosyl chloride 1 and bromides 2 and 3 were stereospecifically transformed into p-nitrophenyl glycosides by phase transfer catalysis; these glycohydrolase substrates were reduced and N-acryloylated to afford Michael acceptors which reacted with amine functions of proteins.
- Roy, Rene,Tropper, Francois D.,Morrison, Tara,Boratynski, Janusz
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p. 536 - 538
(2007/10/02)
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