Parcourir par sujet "Chemistry, Organic"
Voici les éléments 1-17 de 17
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Branched-chain sugar nucleosides: stereocontrolled synthesis and bioevaluation of novel 3 '-C-trifluoromethyl and 3 '-C-methyl pyranonucleosides
(2015)A new series of 3 '-C-trifluoromethyl- and 3 '-C-methyl-beta-D-allopyranonucleosides of 5-fluorouracil and their deoxy derivatives has been designed and synthesized. Treatment of ketosugar 1 with trifluoromethyltrimethylsilane ... -
A concise synthesis of 3-fluoro-5-thio-xylo- and glucopyranoses, useful precursors towards their corresponding pyranonucleoside derivatives
(2008)The chemical synthesis of 1,2,4-tri-O-acetyl-3-deoxy-3-fluoro-5-thio-D-xylopyranose, 1,2,4,6-tetra-O-acetyl-3-deoxy-3 -fluoro-5-thio-alpha(-D-glucopyranose and their corresponding nucleosides of thymine is described. ... -
Effect of sugars, galactose content and chainlength on freeze-thaw gelation of galactomannans
(2006)Cryogels of locust bean gum (LBG) were prepared by freezing and thawing 1.0 wt% solutions incorporating sucrose, glucose, fructose or sorbitol at concentrations of 40. 45, 50, 55 and 60 wt%, and were characterised by ... -
Efficient synthesis of exomethylene- and keto-exomethylene-D-glucopyranosyl nucleoside analogs as potential cytotoxic agents
(2011)A novel series of exomethylene- and keto-exomethylene-D-glucopyranonucleosides with thymine, uracil, and 5-fluorouracil as heterocyclic bases have been designed and synthesized. Wittig condensation of the 3-keto glucoside ... -
A facile, one-step conversion of 6-O-trityl and 6-O-TBDMS monosaccharides into the corresponding formate esters
(2006)A convenient method has been developed for a facile and high-yield conversion of 6-O-tertbutyldimethylsilyl and 6-O-trityl protected monosaccharides to their formate esters, which may serve as useful intermediates for the ... -
Gelation of high methoxy pectin by acidification with D-glucono-delta-lactone (GDL) at room temperature
(2009)Rheological comparisons have been made between preparations of high methoxy pectin (DE approximate to 70%) gelled by acidification with D-glucono-delta-lactone (GDL) on holding for 16 h at 25 degrees C in the presence of ... -
Keto-fluorothiopyranosyl nucleosides: a convenient synthesis of 2-and 4-keto-3-fluoro-5-thioxylopyranosyl thymine analogs
(2011)A novel series of fluorinated keto-beta-D-5-thioxylopyranonucleosides bearing thymine as the heterocyclic base have been designed and synthesized. Deprotection of 3-deoxy-3-fluoro-5-S-acetyl-5-thio-D-xylofuranose (1) and ... -
"Melt-in-the-mouth" gels from mixtures of xanthan and konjac glucomannan under acidic conditions: A rheological and calorimetric study of the mechanism of synergistic gelation
(2007)The effect of acidification on a typical commercial xanthan and on pyruvate-free xanthan (PFX), alone and in gelling mixtures with konjac glucomarman (KGM), has been studied by differential scanning calorimetry (DSC) and ... -
Molecular Cloning, Carbohydrate Specificity and the Crystal Structure of Two Sclerotium rolfsii Lectin Variants
(2015)SRL is a cell wall associated developmental-stage specific lectin secreted by Sclerotium rolfsii, a soil-born pathogenic fungus. SRL displays specificity for TF antigen (Gal13GalNAc--Ser//Thr) expressed in all cancer types ... -
A novel and easy two-step, microwave-assisted method for the synthesis of halophenyl pyrrolo 2,3-b quinoxalines via their pyrrolo precursors. Evaluation of their bioactivity
(2014)A novel, two-step, facile route for the synthesis of pyrrolo[2,3-b]quinoxalines via 2,3-dioxopyrroles, enhanced by microwave irradiation, is presented. The newly synthesized 2,3-dioxo-5-halophenyl pyrrolo precursors 4a-c ... -
Novel conformationally constrained pyrazole derivatives as potential anti-cancer agents
(2015)The synthesis of 17 novel conformationally constrained pyrazole derivatives is reported herein, along with the assessment of their anti-proliferative and anti-angiogenic activities. The evaluation of their inhibitory effect ... -
Preparation, authentication, rheology and conformation of theta carrageenan
(2010)Lambda carrageenan was extracted from hand-sorted tetrasporophytes of Gigartina skottsbergii. Theta carrageenan was prepared from it by treatment with alkaline borohydride. Infrared spectroscopy showed complete, or essentially ... -
Rapid microwave-enhanced synthesis of C5-alkynyl pyranonucleosides as novel cytotoxic antitumor agents
(2013)A microwave-assisted, one-pot, coupling reaction for the synthesis of C5-alkynyl-uracil and cytosine glucopyranonucleosides has been developed. The reaction is carried out under standard Sonogashira coupling conditions ... -
Stereocontrolled synthesis of 4 '-C-cyano and 4 '-C-cyano-4 '-deoxy pyrimidine pyranonucleosides as potential chemotherapeutic agents
(2012)A new series of 4'-C-cyano and 4'-C-cyano-4'-deoxy pyrimidine pyranonucleosides has been designed and synthesized. Commercially available 1,2,3,4,6-penta-O-acetyl-D-mannopyranose (1) was condensed with silylated 5-fluorouracil, ... -
Stereoselective facile synthesis of 2 '-spiro pyrimidine pyranonucleosides via their key intermediate 2 '-C-cyano analogues. Evaluation of their bioactivity
(2014)A novel series of 2'-spiro pyrimidine pyranonucleosides has been designed and synthesized. Their precursors, 2'-C-cyano nucleosides 5a,b and 6a,b, were obtained by subjecting 1a,b to the sequence of selective protection ... -
Synthesis of 3-fluoro-6-S-(2-S-pyridyl) nucleosides as potential lead cytostatic agents
(2010)The 3-deoxy-3-fluoro-6-S-(2-S-pyridyl)-6-thio-beta-D-glucopyranosyl nucleoside analogs 7 were prepared via two facile synthetic routes. Their precursors, 3-fluoro-6-thio-glucopyranosyl nucleosides 5a-e, were obtained by ... -
Synthesis of 4,6-dideoxy-3-fluoro-2-keto-beta-D-glucopyranosyl analogues of 5-fluorouracil, N-6-benzoyl adenine, uracil, thymine, N-4-benzoyl cytosine and evaluation of their antitumor activities
(2010)The synthesis of the unsaturated 4,6-dideoxy-3-fluoro-2-keto-beta-D-glucopyranosyl nucleosides of 5-fluorouracil (6a), N-6-benzoyl adenine (6b), uracil (6c), thymine (6d) and N-4-benzoyl cytosine (6e), is described. ...