13089-21-9Relevant articles and documents
Aromatic crown ethers as phase transfer catalysts in the synthesis of N-acetylglucosamine β-aryl glycosides
Chupakhina,Kur'yanov,Chirva,Grigorash,Kotlyar,Kamalov
, p. 301 - 303 (2004)
The crown ether-catalyzed glycosylation of phenol, 4-methoxyphenol, and 4-nitrophenol was studied under phase transfer conditions in solid-liquid system. The asymmetric dibenzocrown esters are superior to [3.3]dibenzo-18- crown-6 and 15-crown-5 in the cat
A phase-transfer glucosamination of phenols catalyzed by polyethylene glycol
Kur'yanov,Priskoka,Chupakhina,Chirva
, p. 300 - 301 (2005)
Glycosylation of phenols with α-D-glucosaminyl chloride peracetate catalyzed by polyethylene glycol (PEG) was carried out in a solid-liquid phase transfer system at room temperature. The results were compared with those previously obtained for the catalys
Copper-Catalyzed Anomeric O-Arylation of Carbohydrate Derivatives at Room Temperature
Verdelet, Tristan,Benmahdjoub, Sara,Benmerad, Belkacem,Alami, Mouad,Messaoudi, Samir
, p. 9226 - 9238 (2019/08/12)
Direct and practical anomeric O-arylation of sugar lactols with substituted arylboronic acids has been established. Using copper catalysis at room temperature under an air atmosphere, the protocol proved to be general, and a variety of aryl O-glycosides have been prepared in good to excellent yields. Furthermore, this approach was extended successfully to unprotected carbohydrates, including α-mannose, and it was demonstrated here how the interaction between carbohydrates and boronic acids can be combined with copper catalysis to achieve selective anomeric O-arylation.
Chemical synthesis of 4-azido-β-galactosamine derivatives for inhibitors of N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase
Hor, Seanghai,Kodama, Takumi,Sugiura, Nobuo,Kondou, Hikaru,Yanagida, Mio,Yanagisawa, Keiya,Shibasawa, Aoki,Tsuzuki, Bunta,Fukatsu, Naoto,Nagao, Kazuya,Yamana, Kenji,Hidari, Kazuya I. P. J.,Watanabe, Hideto,Habuchi, Osami,Nakano, Hirofumi
, p. 477 - 491 (2018/09/20)
Chondroitin sulfate E (CS-E) plays a crucial role in diverse processes ranging from viral infection to neuroregeneration. Its regiospecific sulfation pattern, generated by N-acetylgalactosamine 4-sulfate 6-O-sulfotransferase (GalNAc4S-6ST), is the main structural determinant of its biological activity. Inhibitors of GalNAc4S-6ST can serve as powerful tools for understanding physiological functions of CS-E and its potential therapeutic leads for human diseases. A family of new 4-acylamino-β-GalNAc derivatives and 4-azido-β-GalNAc derivatives were synthesized for their potential application as inhibitors of GalNAc4S-6ST. The target compounds were evaluated for their inhibitory activities against GalNAc4S-6ST. The results revealed that 4-pivaloylamino- and 4-azido-β-GalNAc derivatives displayed evident activities against GalNAc4S-6ST with IC50 value ranging from 0.800 to 0.828?mM. They showed higher activities than benzyl D-GalNAc4S that was used as control.
Facile synthesis of nitrophenyl 2-acetamido-2-deoxy-α-D- mannopyranosides from ManNAc-oxazoline
Krenek, Karel,Simon, Petr,Weignerova, Lenka,Fliedrova, Barbora,Kuzma, Marek,Kren, Vladimir
, p. 428 - 432 (2012/05/05)
The synthetic procedures for a large-scale preparation of o- and p-nitrophenyl 2-acetamido-2-deoxy-α-D-mannopyranoside are described. The synthetic pathway employs the glycosylation of phenol with ManNAc oxazoline, followed by nitration of the aromatic moiety yielding a separable mixture of the o- and p-nitrophenyl derivative in a 2:3 ratio.
Probing synergy between two catalytic strategies in the glycoside hydrolase O-GlcNAcase using multiple linear free energy relationships
Greig, Ian R.,Macauley, Matthew S.,Williams, Ian H.,Vocadlo, David J.
supporting information; experimental part, p. 13415 - 13422 (2010/01/16)
Human O-GlcNAcase plays an important role in regulating the post-translational modification of serine and threonine residues with β-O-linked N-acetylglucosamine monosaccharide unit (O-GlcNAc). The mechanism of O-GlcNAcase involves nucleophilic participation of the 2-acetamido group of the substrate to displace a glycosidically linked leaving group. The tolerance of this enzyme for variation in substrate structure has enabled us to characterize O-GlcNAcase transition states using several series of substrates to generate multiple simultaneous free-energy relationships. Patterns revealing changes in mechanism, transition state, and rate-determining step upon concomitant variation of both nucleophilic strength and leaving group abilities are observed. The observed changes in mechanism reflect the roles played by the enzymic general acid and the catalytic nucleophile. Significantly, these results illustrate how the enzyme synergistically harnesses both modes of catalysis; a feature that eludes many small molecule models of catalysis. These studies also suggest the kinetic significance of an oxocarbenium ion intermediate in the O-GlcNAcase-catalyzed hydrolysis of glucosaminides, probing the limits of what may be learned using nonatomistic investigations of enzymic transition-state structure and offering general insights into how the superfamily of retaining glycoside hydrolases act as efficient catalysts.
Hydration of Sugars in the gas phase: Regioselectivity and conformational choice in N-acetyl glucosamine and glucose
Cocinero, Emilio J.,Stanca-Kaposta, E. Cristina,Dethlefsen, Mark,Liu, Bo,Gamblin, David P.,Davis, Benjamin G.,Simons, John P.
supporting information; experimental part, p. 13427 - 13434 (2010/04/30)
The influence of an acetamido group in directing the preferred choice of hydration sites in glucosamine and a consequent extension of the working rules governing regioselective hydration and conformational choice, have been revealed through comparisons between the conformations and structures of "free" and multiply hydrated phenyl N-acetyl-β-D-glucosamine (sβpGlcNAc) and phenyl β-D-glucopyranoside (βpGlc), isolated in the gas phase at low temperatures. The structures have been assigned through infrared ion depletion spectroscopy conducted in a supersonic jet expansion, coupled with computational methods. The acetamido motif provides a hydration focus that overwhelms the directing role of the hydroxymethyl group; in multiply hydrated βpGlcNAc the water molecules are all located around the acetamido motif, on the "axial" faces of the pyranose ring rather than around its edge, despite the equatorial disposition of all the hydrophilic groups in the ring. The striking and unprecedented role of the C-2 acetamido group in controlling hydration structures may, in part, explain the differing and widespread roles of GlcNAc, and perhaps GalNAc, in nature.
O-GlcNAcase catalyzes cleavage of thioglycosides without general acid catalysis
Macauley, Matthew S.,Stubbs, Keith A.,Vocadlo, David J.
, p. 17202 - 17203 (2007/10/03)
O-GlcNAcase catalyzes the removal of N-acetylglucosamine residues from serine and threonine residues of post-translationally modified proteins using a catalytic mechanism involving substrate-assisted catalysis and general acid/base catalysis. Since thioglycosides are widely perceived as resistant to hydrolysis by glycosidases, it was surprising to find that O-GlcNAcase also catalyzes the efficient hydrolysis of S-glycosides. Bronsted analyses and pH-activity studies of the O-GlcNAcase-catalyzed hydrolysis of a series of aryl S- and O-glycosides reveal that O-GlcNAcase effects hydrolysis of thioglycosides without the assistance of general acid catalysis. α-Deuterium kinetic isotope effects for O- and S-glycosides, as well as Taft-like analyses using N-fluoroacetyl-β-glycosides, suggest that O-GlcNAcase accomplishes hydrolysis of thioglycosides by stabilizing late transition states. For S-glycosides this transition state shows greater nucleophilic participation from the 2-acetamido group than for O-glycosides. The rate constants governing the O-GlcNAcase-catalyzed hydrolysis of O- and S-glycosides as compared to those previously determined for the spontaneous hydrolysis of structurally similar O,O- and O,S-acetals show a similar ratio. O-GlcNAcase therefore demonstrates similar catalytic proficiency toward both O- and S-glycosides. We conclude that O-GlcNAcase is a bifunctional catalyst capable of efficiently cleaving thioglycosides without general acid catalysis, an observation that may have biological implications. Copyright
Synthesis of N-Acetylmuramyl-L-Alanyl-D-Isoglutamine Aryl β-Glycosides
Zemlyakov,Tsikalov,Kur'yanov,Chirva,Bovin
, p. 390 - 394 (2007/10/03)
Synthesis of N-acetylmuramyl-L-alanyl-D-isoglutamine phenyl and (2-naphthyl) β-glycosides, novel muramyl dipeptide derivatives with phenolic aglycons, was reported. The starting N-acetylglucosamine aryl glycosides were obtained by glycosylation of phenols with peracetylated α-glucosaminyl chloride under the conditions of phase-transfer catalysis and used for the synthesis of 4,6-O-isopropylidene-N-acetylmyramic acid aryl β-glycosides. Condensation of these derivatives with a dipeptide and subsequent deprotection resulted in the intended glycopeptides.
Synthesis of N-Acetylglucosamine Aryl β-Glycosides Catalyzed by Crown Compounds
Kur'yanov,Chupakhina,Zemlyakov,Kotlyar,Kamalov,Chirva
, p. 385 - 389 (2007/10/03)
Glycosylation of various phenols with α-D-glucosaminyl chloride peracetate in a solid phase-liquid system catalyzed by crown compounds was studied. The highest yields of aryl β-glycosides were observed at room temperature in acetonitrile using anhydrous p
