- Sulfatase-catalyzed assembly of regioselectively O-sulfonated p-nitrophenyl α-D-gluco- and α-D-mannopyranosides
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A chemoenzymic methodology is extended to the library synthesis of regioselectively O-sulfonated pNP D-gluco and D-mannopyranosides. The method involves the sequential reactions of chemical O-sulfonation and sulfatase-catalyzed O-desulfonation. pNP 2,6-di-O-sulfo-α-D- glucopyranoside and pNP 3,6-di-O-sulfo-α-D-mannopyranoside were obtained as sodium salts using chemical methods by way of dibutylstannylene acetals or tributylstannyl ethers. They were then applied to enzyme reactions using three molluscan enzymes (snail, limpet, and abalone). The sulfatase reactions cleaved a sulfate group at the secondary O-2 or O-3 position to yield the corresponding pNP 6-O-sulfo sugars. Neither pNP 6-O-sulfo-α-D-glucopyranoside nor 6-O-sulfo-α-D-mannopyranoside became the enzyme substrate. Evidently, the molluscan sulfatases have a tendency to cleave the secondary O-sulfo group with assistance from the 6-O-sulfo group.
- Uzawa, Hirotaka,Nishida, Yoshihiro,Sasaki, Kenji,Nagatsuka, Takehiro,Hiramatsu, Hideo,Kobayashi, Kazukiyo
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- Direct Synthesis of para-Nitrophenyl Glycosides from Reducing Sugars in Water
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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
- Fairbanks, Antony J.,Qiu, Xin
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- Post-photoaffinity labeling modification using aldehyde chemistry to produce a fluorescent lectin toward saccharide-biosensors
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A new method to construct a fluorescent saccharide biosensor based on a lectin protein is successfully proposed using post-photoaffinity labeling modification coupled to aldehyde chemistry.
- Nagase,Shinkai,Hamachi
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- Brain-targeting nano liposome carrying positively charged polymer/miR-195 compound, and preparation method and application thereof
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The invention relates to a brain-targeting nano liposome carrying a positively charged polymer/miR-195 compound, and a preparation method and application thereof, and belongs to the technical field oftargeting drug delivery. In order to improve stability of nucleic acid therapeutic drugs and penetration of blood brain barriers, the invention provides the brain targeting nano liposome carrying thepositively charged polymer/miR-195 compound, wherein the liposome containing a glycosyl modified polyethylene glycol phospholipid and a cell penetrating peptide modified polyethylene glycol phospholipid is taken as a drug carrier to envelop the positively charged polymer/miR-195 compound. According to the invention, stability of miR-195 is improved through the positively charged polymer and the drug carrier, and capability of the drug to target the brain and penetrate the cell membrane is improved through the glycosyl combined cell penetrating peptide modified brain targeting nano liposome, so that the carried drugs efficiently and specifically target brain tissues to treat Alzheimer's disease and vascular dementia, particularly cognitive dysfunction caused by Alzheimer's disease and cerebral ischemia.
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- Glycosyl-based united cell penetrating peptide-modified brain-targeted nano-liposome as well as preparation method and application thereof (by machine translation)
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The invention relates to a glycosyl combined cell penetrating peptide-modified brain-targeted nano-liposome and a preparation method and application thereof, and belongs to the technical field of targeted drug delivery. The liposome comprises EPC, CHO, glycosyl modified polyethylene glycol phospholipid and cell penetrating peptide modified polyethylene glycol phospholipid with a certain molar ratio. By simultaneously modifying the glycosyl and the cell penetrating peptide on the surface of the nano liposome, the nano lipidosome has the capability of actively targeting brain and penetrating cell membranes. The drug carrier is used for a drug carrier, so that the carried medicines can efficiently and specifically target brain tissues and enter into brain cells to play a role. The in-vitro cell test and the in-vivo distribution experiment prove that the brain-targeted nano-liposome provided by the invention can reach the brain smoothly and accumulate in brain cells to exert efficacy. (by machine translation)
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Paragraph 0072; 0076
(2020/06/30)
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- A process for preparing nitro phenyl - α - D - pyran honeydews glycoside method
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The invention discloses a p-nitrophenyl-alpha-D-mannopyranoside preparation method. The p-nitrophenyl-alpha-D-mannopyranoside preparation method is characterized by including (1), in the presence of catalysts, enabling alpha-D-mannose under protection to contact with p-nitrophenol under the coupling reaction condition so as to obtain p-nitrophenyl-alpha-D-mannoside under protection; (2), subjecting the p-nitrophenyl-alpha-D-mannoside under protection, obtained in the step (1), to deprotection so as to obtain p-nitrophenyl-alpha-D-mannopyranoside. The p-nitrophenyl-alpha-D-mannopyranoside preparation method has the advantages of short reaction route, simplicity and convenience in operation, high yield, short reaction time and low cost.
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Paragraph 0053; 0056; 0059
(2018/03/01)
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- COMPOUNDS AND METHODS FOR TREATING BACTERIAL INFECTIONS
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The present invention encompasses compounds and methods for treating urinary tract infections.
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Page/Page column 69-70
(2011/05/06)
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- Syntheses of p-nitrophenyl 3- and 4-thio-β-d-glycopyranosides
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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
- Chen, Hong-Ming,Withers, Stephen G.
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experimental part
p. 2596 - 2604
(2011/01/12)
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- Stereospecific α-D-mannosylation
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The stereospecific formation of α-D-mannosyl glycosidic linkages has been achieved in high yield using tetra-O-pivaloyl-α-D-mannopyranosyl fluoride and boron trifluoride diethyl etherate in dichloromethane. Examples of the α-D-mannosylation of primary, secondary, benzylic and phenolic hydroxyl groups are described. Copyright (C) 1999 Elsevier Science Ltd.
- Scott, Ian L.,Market, Robert V.,DeOrazio, Russell J.,Meckler, Harold,Kogan, Timothy P.
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p. 210 - 216
(2007/10/03)
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- Carbohydrate-carbohydrate interactions in water with glycophanes as model systems
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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.
- Morales, Juan Carlos,Zurita, Dacil,Penades, Soledad
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p. 9212 - 9222
(2007/10/03)
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