- Regiospecific synthesis of lactose analog Gal-(β 1,4)-Xyl by transgalactosylation
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A short enzymatic synthesis of disaccharide 4-O-β-D-galactopyranosyl-D-xylose (1) has been developed, which is of interest as a lactose analog for a non-invasive medicinal determination of lactose intolerance. The starting material, benzyl α-D-xyloside, was obtained by a Fischer-type glycosidation of D-xylose with benzyl alcohol, followed by anomeric differentiation of mixed glycosides using a glycosidase from Aspergillus oryzae. From several commercial β-galactosidases, which were screened for their transgalactosylation capacity, the enzyme from Escherichia coli was found to catalyze a virtually regio- and stereospecific galactosyl transfer from donor compounds o-nitrophenyl β-D-galactoside or lactose to the α-D-xyloside. Subsequent hydrogenolytic deprotection furnished desired disaccharide 1.
- Fessner, Wolf-Dieter,Juarez Ruiz, Juan Manuel
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- Anomeric alkylations and acylations of unprotected mono- and disaccharides mediated by pyridoneimine in aqueous solutions
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A site-specific deprotonation followed by alkylations and acylations of sugar hemiacetals to the corresponding alkyl glycosides and acylated sugars in aqueous solutions is disclosed herein. Pyridoneimine as a new base is developed to mediate the deprotonation of readily available sugar hemiacetals and further reactions with alkylation and acylation agents.
- Dey, Kalyan,Jayaraman, Narayanaswamy
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supporting information
p. 2224 - 2227
(2022/02/17)
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- A Rapid and Mild Sulfation Strategy Reveals Conformational Preferences in Therapeutically Relevant Sulfated Xylooligosaccharides
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Although sulfated xylooligosaccharides are promising therapeutic leads for a multitude of afflictions, the structural complexity and heterogeneity of commercially deployed forms (e. g. Pentosan polysulfate 1) complicates their path to further clinical development. We describe herein the synthesis of the largest homogeneous persulfated xylooligomers prepared to date, comprising up to eight xylose residues, as standards for biological studies. Near quantitative sulfation was accomplished using a remarkably mild and operationally simple protocol which avoids the need for high temperatures and a large excess of the sulfating reagent. Moreover, the sulfated xylooligomer standards so obtained enabled definitive identification of a pyridinium contaminant in a sample of a commercially prepared Pentosan drug and provided significant insights into the conformational preferences of the constituent persulfated monosaccharide residues. As the spatial distribution of sulfates is a key determinant of the binding of sulfated oligosaccharides to endogenous targets, these findings have broad implications for the advancement of Pentosan-based treatments.
- Vo, Yen,Schwartz, Brett D.,Onagi, Hideki,Ward, Jas S.,Gardiner, Michael G.,Banwell, Martin G.,Nelms, Keats,Malins, Lara R.
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supporting information
p. 9830 - 9838
(2021/06/01)
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- Synthesis, conformational analysis and SAR research of OSW-1 analogues
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A series of novel OSW-1 analogues were synthesized by coupling disaccharides (2-O-4-methoxylbenzoyl-β-D-xylopyranosyl-(1→3)-2-O-acetyl-α-L-arabinopyranosyl) or (2-O-4-(E)-cinnamoyl-β-D-xylopyranosyl-(1→3)-2-O-acetyl-α-L-arabinopyranosyl) and their 1→4 lin
- Liu, Chao,Wang, A-peng,Jin, Longlong,Guo, Yanshen,Li, Yan,Zhao, Zhehui,Lei, Pingsheng
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p. 4091 - 4102
(2016/07/06)
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- Novel D-xylose derivatives stimulate muscle glucose uptake by activating AMP-activated protein kinase α
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Type 2 diabetes mellitus has reached epidemic proportions; therefore, the search for novel antihyperglycemic drugs is intense. We have discovered that D-xylose increases the rate of glucose transport in a non-insulin-dependent manner in rat and human myot
- Gruzman, Arie,Shamni, Ofer,Yakir, Moriya Ben,Sandovski, Daphna,Elgart, Anna,Alpert, Evgenia,Cohen, Guy,Hoffman, Amnon,Katzhendler, Yehoshua,Cerasi, Erol,Sasson, Shlomo
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supporting information; experimental part
p. 8096 - 8108
(2009/12/07)
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- Synthesis of pentose-containing disahharides using a thermostable α-L-arabinofuranosidase
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To date, the enzymatically-catalysed synthesis of pentose-containing compounds has been limited to the production of oligo-β-(1->3)- and oligo-β-(1->4)-linked xylopyranosides. To our knowledge, no such syntheses have involved arabinofuranose or, indeed, a
- Remond, Caroline,Plantier-Royon, Richard,Aubry, Nathalie,Maes, Emmanuel,Bliard, Christophe,O'Donuhue, Michael J.
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p. 2018 - 2026
(2007/10/03)
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- First total synthesis of an exceptionally potent antitumor saponin, OSW- 1
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OSW-1 (1), an acylated disaccharide cholestane saponin from Ornithogalum saudersiae with exceptionally potent antitumor activity, was first synthesized from commercially available dehydroisoandrosterone, L-arabinose, and D-xylose in total 27 steps with the longest linear sequence of 14 steps and in 6% yield.
- Deng, Shaojiang,Yu, Biao,Lou, Yun,Hui, Yongzheng
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p. 202 - 208
(2007/10/03)
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- Stereoselective Syntheses of α-Glucuronides Using Dehydrative Glycosylation
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Methyl and benzyl 2,3,4-tri-O-benzyl-D-glucopyranuronates, prepared from D-glucurono-6,3-lactone, afforded selectively the corresponding α-glucopyranosiduronates by the aid of the condensing reagent system composed of p-nitrobenzenesulfonyl chloride, silver trifluoromethanesulfonate, and triethylamine. Using this method, O-α-D-glucopyranuronosyl-(1→3)-O-α-L-arabinofuranosyl- (1→3)-D-xylopyranose, one of the minimal component units in the structure of plantago-mucilage A from the seeds of Plantago asiatica Linne constituting a Chinese medicine : chegianzi [HU~P].
- Koto, Shinkiti,Miura, Teruhisa,Hirooka, Motoko,Tomaru, Aya,Iida, Mika,Kanemitsu, Masanori,Takenaka, Kazuhiro,Masuzawa, Shinichi,Miyaji, Saeko,Kuroyanagi, Naoko,Yagishita, Miki,Zen, Shonosuke,Yago, Kazuo,Tomonaga, Fumiya
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p. 3247 - 3259
(2007/10/03)
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- Regioselective Protection Strategies for D-Xylopyranosides
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The acylation of D-xylopyranosides can be effected at any position by selective hydroxyl activation with dibutyltin oxide in refluxing benzene and proper choice of starting anomer.Methyl 4-O-benzyl-β-D-xylopyranoside, available from methyl 2,3-O-isopropyl
- Helm, Richard F.,Ralph, John,Anderson, Laurens
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p. 7015 - 7021
(2007/10/02)
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- Pseudomonic Acid C from L-Lyxose
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Full details of the total synthesis of pseudomonic acid C from L-lyxose are described.Key features of the approach involve feee-radical allylation for stereoselective C-C bond formation at C4 of lyxose, Frater alkylation to generate correct stereochemistry at C12 and C13, and stereoselective intramolecular Michael addition to establish the correct stereochemistry of the "anomeric" appendage.
- Keck, Garry E.,Kachensky, David F.,Enholm, Eric J.
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p. 4317 - 4325
(2007/10/02)
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- Pentoside Synthesis by Dehydrative Glykosylation. Synthesis of O-α-L-Arabinofuranosyl-(1-3)-O-β-D-xylopyranosyl-(1-4)-D-xylopyranose
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O-α-L-Arabinofuranosyl-(1-3)-O-β-D-xylopyranosyl-(1-4)-D-xylopyranose isolated from the hydrolyzate of corncobs arabinoxylan was synthesized by way of dehydrative glycosylation.
- Koto, Shinkiti,Morishima, Naohiko,Takenaka, Kazuhiro,Uchida, Chisa,Zen, Shonosuke
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p. 1464 - 1468
(2007/10/02)
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- Total Synthesis of Pseudomonic Acid C
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A convergent total synthesis of pseudomonic acid C from L-lyxose is described in which a highly stereoselective free-radical C-C bond construction plays a key role.
- Keck, Gary E.,Kachensky, David F.,Enholm, Eric J.
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p. 1462 - 1464
(2007/10/02)
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