- PURINE AND PYRIMIDINE NUCLEOTIDES AS ECTO-5'-NUCLEOTIDASE INHIBITORS
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Disclosed is a compound of formula (I), wherein Q, U, T, A, a, b, c, and n are as defined herein. Also disclosed are methods of inhibiting ecto?5'?nucleotidase, inhibiting suppression of an antitumor immune response, inhibiting tumor growth of a cancerous
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Paragraph 0185; 0223
(2020/03/05)
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- A versatile synthesis of 5'-fenctionalized nucleosides through regioselective enzymatic hydrolysis of their peracetylated precursors
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We describe a chemo-enzymatic synthesis of modified nucleosides through lipase-catalyzed hydrolysis of their peracetylated precursors. It was found from screening of a large number of substrates that these enzymesregioselectivities were affected by the sugar and the nucleobase structures. By selecting the best enzyme for each substrate in terms of activity and regioselectivity, we prepared a small library of differently monodeprotecled purine and pyrimidine nucleosides useful as intermediates for the synthesis of high-value nucleosides and mononucleotides. By this approach, the chemo-enzymatic preparation of doxifluridine (14) and uridine 5'-monophosphate (5'-UMP, 15) from peracetylated uridine 1 was carried out. Elimination of many of the processing stages associated with existing methods was achieved, and higher yields and products of increased purity were generated. Wiley-VCH Verlag GmbH & Co. KGaA.
- Bavaro, Teodora,Rocchietti, Silvia,Ubiali,Filice, Marco,Terreni, Marco,Pregnolato, Massimo
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experimental part
p. 1967 - 1975
(2009/09/08)
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- Pyridine-free and solvent-free acetylation of nucleosides promoted by molecular sieves
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A practical method for the acetylation of purine and pyrimidine nucleosides employing a combination of acetic anhydride and potassium-exchanged molecular sieves is described. Besides the high yields obtained for the acylated nucleosides, the procedure is simple, inexpensive and environmentally benign, avoiding the use of pyridine or co-solvents as additives. Georg Thieme Verlag Stuttgart.
- Sá, Marcus Mandolesi,Meier, Lidiane
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p. 3474 - 3478
(2007/10/03)
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- Nucleic acid related compounds. 127. Selective N-deacylation of N,O-peracylated nucleosides in superheated methanol
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Solutions of peracylated adenosine, cytidine, and related nucleoside derivatives undergo selective N-deacylation upon heating at elevated temperatures (oil bath ≥ 105 °C) in methanol. An increase in the bulk of the N-acyl group has little effect on the rate of N-deacylation but increases the N/O selectivity ratio. Extended heating is required for N-deacylation with arylcarboxylic acid derivatives. Contamination with acidic or basic reagent residues is avoided.
- Nowak, Ireneusz,Conda-Sheridan, Martin,Robins, Morris J.
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p. 7455 - 7458
(2007/10/03)
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- Hydrothermal deamidation of 4-N-acylcytosine nucleoside derivatives: Efficient synthesis of uracil nucleoside esters
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(Chemical Equation Presented) N,O-Peracylated cytidine and 2′-deoxycytidine derivatives in superheated water/DME solutions (oil bath at 125°C) undergo hydrolytic deamidation (and/or N-deacylation). Acylated starting materials derived from arylcarboxylic acids give the corresponding uridine esters cleanly, and such derivatives crystallize selectively from the cooled reaction mixtures in high yields.
- Nowak, Ireneusz,Robins, Morris J.
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p. 4903 - 4905
(2007/10/03)
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- Synthesis of a new transition-state analog of the sialyl donor. Inhibition of sialyltransferases
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A new class of glycosyltransferase inhibitor has been designed and synthesized. The designed inhibitors 3a/3b provide conformational mimicry of the transition state in sialyltransfer reactions. The key synthetic steps involve a Meinwald rearrangement and a palladium-catalyzed carbonylation reaction. The results of kinetic studies show that 3a/3b exhibit significant inhibition on both 2,3- and 2,6-sialytransferases.
- Sun, Hongbin,Yang, Jingsong,Amaral, Katie E.,Horenstein, Benjamin A.
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p. 2451 - 2453
(2007/10/03)
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- Synthesis of regioselectively protected forms of cytidine based on enzyme-catalyzed deacetylation as the key step
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N4-Acetylcytidine (77%) and 2′,3′-O, N4-triacetylcytidine (95%) were obtained from the hydrolysis of a common precursor, the peracetylated form of cytidine with Aspergillus niger lipase (Amano A) and Burkholderia cepacia esterase (SC esterase S), respectively, under very mild conditions. The experimental procedure for the conversion of triacetylcytidine to a corresponding phosphoramidite (82%), an intermediate for sugar nucleotide synthesis, is also elaborated.
- Kuboki, Atsuhito,Ishihara, Takashi,Kobayashi, Eiko,Ohta, Hiromichi,Ishii, Takeshi,Inoue, Ayumu,Mitsuda, Satoshi,Miyazaki, Tatsuo,Kajihara, Yasuhiro,Sugai, Takeshi
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p. 363 - 368
(2007/10/03)
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- One-pot synthesis of nucleosides using bismuth (III) bromide as catalyst
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A peracetylated α-D-ribofuranosyl bromide reacted with silylated heterocyclic bases in the presence of bismuth (III) bromide (a non-toxic catalyst) in a one-pot procedure to give the corresponding β-D-nucleoside in good yield.
- Winum, Jean-Yves,Kamal, Mehrnaz,Barragan, Veronique,Leydet, Alain,Montero, Jean-Louis
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p. 603 - 606
(2007/10/03)
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- Nucleoside synthesis from thioglycosides
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Acetylated phenyl and methyl 1-thiofurano- and pyranosides react with silylated uracil, acetylcytosine, and benzoyladenine under the influence of NIS/triflic acid to generate the β-nucleoside derivatives in good yield.
- Knapp,Shieh
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p. 3627 - 3630
(2007/10/02)
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