- Non-natural aldofuranosides as substrates of a β-glucosidase
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Based on glycosidase inhibitory activities of some known 1,4-iminoalditols, four aldofuranosides, (4-nitro)phenyl β-d-glucofuranoside, -β-d-galactofuranoside, -α-l-idofuranoside and -α-l- altrofuranoside, were identified as possible substrates of glucosid
- Tauss, Andreas,Greimel, Peter,Rupitz, Karen,Steiner, Andreas J.,Stuetz, Arnold E.,Withers, Stephen G.,Wrodnigg, Tanja M.
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p. 159 - 165
(2007/10/03)
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- A mild and efficient method for the chemoselective deprotection of acetonides with lanthanum(III) nitrate hexahydrate
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Acetonides are hydrolyzed selectively and efficiently with lanthanum(III) nitrate hexahydrate in acetonitrile. The method has good compatibility with other sensitive hydroxyl protecting groups such as trityl, TBDMS, THP, OAc, OBz and OBn.
- Malla Reddy,Venkat Reddy,Venkateswarlu
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p. 7439 - 7441
(2007/10/03)
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- A Simple and Facile Chemo- and Regioselective Deprotection of Acetonides Using Silica Supported Sodium Hydrogen Sulfate as a Heterogeneous Catalyst
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Silica supported sodium hydrogen sulfate (NaHSO4·SiO 2) has been found to be an efficient heterogeneous catalyst for chemo- and regioselective deprotection of acetonides at room temperature to produce the corresponding diols in excellent yields.
- Mahender,Ramu,Ramesh,Das, Biswanath
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p. 734 - 735
(2007/10/03)
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- The role of the C-3 substituent in the asymmetric dihydroxylation of hexo-5-enofuranosides
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Asymmetric dihydroxylation of vinyl furanosides 1-6 by use of OsO4, AD-mix-α and β is described yielding the corresponding hexofuranose sugars. Vinyl furanosides 2 and 3, with an ester group at C-3, and vinyl manno furanoside 5 on asymmetric dihydroxylation with AD-mix α exhibited high R diastereoselectivity at C-5. Reversal in diastereoselectivity at C-5 was observed for the 3-deoxy vinyl furanoside 6 giving furanosaccharide 6S with the S configuration at C-5.
- Mereyala, Hari Babu,Goud, P. Mallikarjun,Gadikota, Rajendrakumar Reddy,Maddala, Rama Krishna,Reddy, K. Ramasubba
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p. 1201 - 1210
(2007/10/03)
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- Synthesis of 5-amino-5-deoxy-D-galactopyranose and 1,5-dideoxy-1,5-imino-D-galactitol, and their inhibition of alpha- and beta-D-galactosidases.
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A 12-step route is presented starting from 1,2:5,6-di-O-isopropylidene-alpha-D-glucofuranose for the preparation of the title compounds and their L-altro analogues. Their synthesis is based on the reduction with Raney nickel of a protected 5-hydroxyimino derivative of L-arabino-hexofuranos-5-ulose, with the following improvements for the preparation of a D-galactofuranose derivative: oxidation at C-3 with pyridinium dichromate-acetic anhydride, stereospecific reduction of a 3-O-acetyl-hex-3-enofuranose intermediate to the D-gulo derivative, and inversion at C-3 of its 3-tosylate with tetrabutylammonium acetate in chlorobenzene. alpha-D-Galactosidase from coffee beans and from Escherichia coli and beta-D-galactosidase from E. coli and Aspergillus wentii were inhibited with Ki values that ranged from 0.0007 to 8.2 microM. Formation of the enzyme-inhibitor complexes with the D-galactose analogue was on the time-scale of minutes, whereas the D-galactitol analogue showed a slow approach to the inhibition only with alpha-D-galactosidase from coffee beans and beta-D-galactosidase from A. wentii. N-Alkylation of the D-galactitol analogue was detrimental to the inhibition except for beta-D-galactosidase from E. coli and beta-D-glucosidase from almonds, but, even with these enzymes, the observed affinity enhancements were 10(2) to 10(3)-times smaller than those of N-alkylated D-galactosylamine and D-glucosylamine.
- Legler,Pohl
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p. 119 - 129
(2007/10/02)
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- Anthracyclinones, Part 4. The Use of DBN or DBU in a Novel Extension of the Marschalk Reaction leading to Hydroxyglycitylanthraquinones
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Leuco-quinizarin (1) with propanal, 3-O-(p-chlorobenzyl)-(or 3-O-acetyl)-1,2-O-isopropylidene-α-D-xylo-pentodialdo-1,4-furanose (6a) or (6c), or 3-O-acetyl-3-C-ethynyl-1,2-O-isopropylidene-α-D-ribo-pentodialdo-1,4-furanose (6b) in dimethylformamide soluti
- Qureshi, Shireen,Shaw, Gordon,Burgess, E. Gillian
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p. 1557 - 1564
(2007/10/02)
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