3150-24-1Relevant articles and documents
Direct Synthesis of para-Nitrophenyl Glycosides from Reducing Sugars in Water
Fairbanks, Antony J.,Qiu, Xin
supporting information, (2020/03/24)
Reducing sugars may be directly converted into the corresponding para-nitrophenyl (pNP) glycosides using 2-chloro-1,3-dimethylimidazolinium chloride (DMC), para-nitrophenol, and a suitable base in aqueous solution. The reaction is stereoselective for sugars with either a hydroxyl or an acetamido group at position 2, yielding the 1,2-trans pNP glycosides. A judicious choice of base allows extension to di-and oligosaccharide substrates, including a complex N-glycan oligosaccharide isolated from natural sources, without the requirement of any protecting group manipulations
Chemo-enzymatic synthesis of p-nitrophenyl β-D-galactofuranosyl disaccharides from Aspergillus sp. fungal-type galactomannan
Ota, Ryo,Okamoto, Yumi,Vavricka, Christopher J.,Oka, Takuji,Matsunaga, Emiko,Takegawa, Kaoru,Kiyota, Hiromasa,Izumi, Minoru
, p. 99 - 103 (2019/01/16)
β-D-Galactofuranose (Galf) is a component of polysaccharides and glycoconjugates. There are few reports about the involvement of galactofuranosyltransferases and galactofuranosidases (Galf-ases) in the synthesis and degradation of galactofuranose-containing glycans. The cell walls of filamentous fungi in the genus Aspergillus include galactofuranose-containing polysaccharides and glycoconjugates, such as O-glycans, N-glycans, and fungal-type galactomannan, which are important for cell wall integrity. In this study, we investigated the synthesis of p-nitrophenyl β-D-galactofuranoside and its disaccharides by chemo-enzymatic methods including use of galactosidase. The key step was selective removal of the concomitant pyranoside by enzymatic hydrolysis to purify p-nitrophenyl β-D-galactofuranoside, a promising substrate for β-D-galactofuranosidase from Streptomyces species.
Development and optimization of a competitive binding assay for the galactophilic low affinity lectin LecA from: Pseudomonas aeruginosa
Joachim, Ines,Rikker, Sebastian,Hauck, Dirk,Ponader, Daniela,Boden, Sophia,Sommer, Roman,Hartmann, Laura,Titz, Alexander
, p. 7933 - 7948 (2016/08/30)
Infections with the Gram-negative bacterium Pseudomonas aeruginosa result in a high mortality among immunocompromised patients and those with cystic fibrosis. The pathogen can switch from planktonic life to biofilms, and thereby shields itself against antibiotic treatment and host immune defense to establish chronic infections. The bacterial protein LecA, a C-type lectin, is a virulence factor and an integral component for biofilm formation. Inhibition of LecA with its carbohydrate ligands results in reduced biofilm mass, a potential Achilles heel for treatment. Here, we report the development and optimization of a fluorescence polarization-based competitive binding assay with LecA for application in screening of potential inhibitors. As a consequence of the low affinity of d-galactose for LecA, the fluorescent ligand was optimized to reduce protein consumption in the assay. The assay was validated using a set of known inhibitors of LecA and IC50 values in good agreement with the known Kd values were obtained. Finally, we employed the optimized assay to screen sets of synthetic thio-galactosides and natural blood group antigens and report their structure-activity relationship. In addition, we evaluated a multivalent fluorescent assay probe for LecA and report its applicability in an inhibition assay.
CARBOHYDRATE FUNCTIONALISED SURFACES
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, (2014/09/29)
Carbohydrates are biomolecules that are involved in a range of biological processes and play key roles in, for instance, host immune response and cellular adhesion. Accordingly, functionalisation of medical devices such as stents, valves, catheters, prostheses and other devices for in vivoimplantation with carbohydrates is an area in which considerable interest is developing. Disclosed herein are surfaces having carbohydrates immobilised thereon. The carbohydrate has a linker moiety covalently bound thereto and the linker moiety has a carbon atom that forms a covalent bond with an atom on the target surface. The carbon based bond is a strong, non-hydrolysable covalent bond. Diazonium salts are utilised to produce the functionalised surfaces and they are particularly advantageous as they result in non-toxic readily escapable by-products
Glycosynthase with broad substrate specificity-an efficient biocatalyst for the construction of oligosaccharide library
Wei, Jinhua,Lv, Xun,Lue, Yang,Yang, Gangzhu,Fu, Lifeng,Yang, Liu,Wang, Jianjun,Gao, Jianhui,Cheng, Shuihong,Duan, Qian,Jin, Cheng,Li, Xuebing
, p. 2414 - 2419 (2013/05/23)
A versatile glycosynthase (TnG-E338A) with strikingly broad substrate scope has been developed from Thermus nonproteolyticus β-glycosidase (TnG) by using site-directed mutagenesis. The practical utility of this biocatalyst has been demonstrated by the facile generation of a small library containing various oligosaccharides and a steroidal glycoside (total 25 compounds) in up to 100 % isolated yield. Moreover, an array of eight gluco-oligosaccharides has been readily synthesized by the enzyme in a one-pot, parallel reaction, which highlights its potential in the combinatorial construction of a carbohydrate library that will assist glycomic and glycotherapeutic research. Significantly, the enzyme provides a means by which glycosynthase technology may be extended to combinatorial chemistry.
Syntheses of p-nitrophenyl 3- and 4-thio-β-d-glycopyranosides
Chen, Hong-Ming,Withers, Stephen G.
experimental part, p. 2596 - 2604 (2011/01/12)
Thioglycosides have proved to be useful, enzymatically stable analogs of glycosides for structural and mechanistic studies and their synthesis is considerably simplified through the use of thioglycoligases. As part of an investigation into the use of thio
Single-crystal and powder X-ray diffraction and solid-state 13C NMR of p-nitrophenyl glycopyranosides, the derivatives of d-galactose, d-glucose, and d-mannose
Gubica, Tomasz,Temeriusz, Andrzej,Paradowska, Katarzyna,Ostrowski, Andrzej,Klimentowska, Paulina,Cyranski, Michal K.
experimental part, p. 1734 - 1744 (2009/12/09)
The X-ray diffraction patterns, 13C CP MAS NMR spectra, and powder X-ray diffraction analyses were obtained for selected p-nitrophenyl glycosides: α- and β-d-galactopyranosides (1 and 2), α- and β-d-glucopyranosides (3 and 4), and α- and β-d-mannopyranosides (5 and 6). In X-ray diffraction analysis of 1 and 2, characteristic shortening and lengthening of selected bonds were observed in the molecules of 1 due to anomeric effect, and in the crystal lattice of 1 and 2, hydrogen bonds of complex network were detected. In the crystal asymmetric unit of 1 there were two independent molecules, whereas in 2 there was one molecule. For 1 and 3-6 the number of resonances in solid-state 13C NMR spectra exceeded the number of the carbon atoms in the molecules, while for 2 there were distinct singlet resonances in its solid-state NMR spectrum. Furthermore, the powder X-ray diffraction (PXRD) performed for 1-3 and 5 revealed that 1, 3, and 5 existed as single polymorphs proving that the doublets observed in appropriate solid-state NMR spectra were connected with two non-equivalent molecules in the crystal asymmetric unit. On the other hand 2 existed as a mixture of two polymorphs, one of them was almost in agreement with the calculated pattern obtained from XRD (the difference in volumes of the unit cells), and the subsequent unknown polymorph existed in small amounts and therefore it was not observed in solid-state NMR measurements.
Carbohydrate-carbohydrate interactions in water with glycophanes as model systems
Morales, Juan Carlos,Zurita, Dacil,Penades, Soledad
, p. 9212 - 9222 (2007/10/03)
The synthesis and conformational properties of glycophanes 2 and 3 (cyclodextrin-cyclophane hybrid receptors containing two maltose units linked by (4-hydroxymethyl) benzoic acid spacer) are described. The binding properties in water of these receptors with a series of 4-nitrophenyl glycosides with α- and β-configurations at the anomeric center have been studied using 1H NMR spectroscopy and molecular mechanics calculations. A comparison of these properties with those of glycophane 1 (an α,α-trehalose containing glycophane) and α-cyclodextrin (αCD) using the same glycosides shows the existence of a stabilizing contribution to the free energy of binding in the case of of glycophanes but not in the case of the αCD system. This contribution is due to carbohydrate-carbohydrate interactions between both host and guest lipophilic sugar surfaces. Glycophanes 1, 2, and 3 show similar α/β selectivity on binding the ligands, despite the great flexibility of 3 related to 1 and 2. Parallels are drawn between the thermodynamic behavior of these model systems and that proposed for sugar- protein interactions.
Synthesis of linkage-specific sialoside substrates for colorimetric assay of neuraminidases
Kodama,Baum,Paulson
, p. 111 - 119 (2007/10/02)
Neuraminidase substrates suitable for analysis of linkage specificity were enzymically synthesized in good yield by linking N-acetylneuraminic acid (Neup5Ac) to O-6 and O-3 of 4-nitrophenyl-β-D-galactopyranoside with β-D-galactoside-α-(2 → 6)-sialyltransf
Immobilization of Enzymes in Protein Films Prepared Using Transglutaminase
Motoki, Masao,Aso, Hiroshi,Seguro, Katsuya,Nio, Noriki
, p. 997 - 1002 (2007/10/02)
An Αs1-casein film prepared using transglutaminase was applied as a support for immobilized enzymes.That is, the enzyme to be immobilized was added to a mixture of 5percent αs1-casein and transglutaminase.Before gelation by means of the transglutaminase-reaction, the reaction mixture was quickly spread on a horizontal plate.The immobilized enzyme film was removed from the plate after air-drying.Attempts were made to immobilize several enzymes, such as β-glucosidase, α-mannosidase, β-galactosidase and glucose oxidase.None of the immobilized enzymes lost activity on repeated usage.The enzymes tested were evidently immobilized through entrapment in the lattice of the protein film.Some enzymic characteristics of the immobilized enzymes showed that this new technique was as good as other known immobilization methods.
