14581-78-3Relevant academic research and scientific papers
A 4 - hydroxy methyl phenyl - beta - D glucopyranoside synthesis method (by machine translation)
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Paragraph 0026, (2017/07/19)
A 4 - hydroxy methyl phenyl - beta - D glucopyranoside synthetic method, comprises the following steps, step 1. The glycosidation reaction: five acetyl glucose, cresol, montmorillonite, Lewis acid in an organic solvent in the glycosidation reaction, and getting the middle raw material 1, and then in order to methanol recrystallization; step 2. Oxidation reaction: step 1 obtained in the middle of the raw material 1 in an organic solvent is added, by nitric acid ammonium oxidation intermediate raw material 1 obtained after the aldehyde group of the intermediate raw material 2, and then the ethanol solution is recrystallized; step 3. Ester exchange and reduction reaction: the step 2 to obtain the intermediate raw material 2 with methanol catalyst under the action of the ester exchange reaction, to obtain the 4 - formyl phenyl - beta - D - glucopyranoside, adding the borohydride reduction, to obtain the final product; the invention effectively solves the current Gastrodin synthesis in present technology; with more economic, environmental protection, safe and convenient operation, industrialization with stronger adaptability characteristics. (by machine translation)
Multiplex detection of enzymatic activity with responsive lanthanide-based luminescent probes
Pershagen, Elias,Borbas, K. Eszter
supporting information, p. 1787 - 1790 (2015/02/19)
Multiplex analyte detection in complex dynamic systems is desirable for the investigation of cellular communication networks as well as in medical diagnostics. A family of lanthanide-based responsive luminescent probes for multiplex detection is reported. The high modularity of the probe design enabled the rapid assembly of both green and red emitters for a large variety of analytes by the simple exchange of the lanthanide or an analyte-cleavable caging group, respectively. The real-time three-color detection of up to three analytes was demonstrated, thus setting the stage for the non-invasive investigation of interconnected biological processes. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA , Weinheim.
Improved synthesis of gastrodin, a bioactive component of a traditional chinese medicine
Li, Yu-Wen,Ma, Cui-Li
, p. 1205 - 1212 (2015/01/30)
Highly practical, four-step synthesis of gastrodin was developed using penta- O-acetyl-β-D-glucopyranose and p-cresol as glycosyl donor and glycosyl acceptor, respectively, in 58.1% overall yield. As the initial step, the penta-O-acetyl-β-D-glucopyranose was treated with p-cresol in the presence of BF3 ?Et2O as catalyst to generate 4-methylphenyl 2,3,4,6-tetra-O-acetyl-β-D- -glucopyranoside in 76.3% yield. Further, this product was subjected to radical bromination with N-bromosuccinimide (NBS) to provide 4-(bromomethyl)phenyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside in 91% yield. Subsequently, reaction of 4-(bromomethyl)phenyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside with a solution of acetone and saturated aqueous sodium bicarbonate led to 4-(hydroxymethyl)phenyl 2,3,4,6-tetra-O-acetyl-β-D-glucopyranoside in 93% yield. Finally, global deprotection of 4-(hydroxymethyl)phenyl 2,3,4,6-tetra-O- -acetyl-β- D-glucopyranoside under Zemplen conditions furnished gastrodin in 90% yield. Compared to the previously reported methods, this protocol has the advantages of operational simplicity, chromatography-free separation, high overall yield, inexpensive and common reagents as well as less waste pollutants, rendering it an alternative suitable for industrial production.
Revisit of the phenol O-glycosylation with glycosyl imidates, BF 3·OEt2 is a better catalyst than TMSOTf
Li, Yali,Mo, Huaping,Lian, Gaoyan,Yu, Biao
, p. 14 - 22 (2013/01/15)
With BF3·OEt2 as the catalyst, the glycosylation of phenols with glycosyl trichloroacetimidates (or N-phenyl trifluoroacetimidates) bearing 2-O-participating groups leads to the desired 1,2-trans-O-glycosides in generally excellent yields without formation of the 1,2-cis-anomers. However, with TMSOTf as the catalyst, the outcomes of the corresponding phenol O-glycosylation are highly dependent on the nucleophilicity of the phenols; less nucleophilic is the phenol, higher amounts of the 1,2-cis-O-glycoside together with more side-products are generated. 1,2-Orthoesters have been found to be the major products at a low temperature (a higher temperature. BF 3·OEt2 is an effective catalyst to promote the conversion of 1,2-orthoesters into the corresponding 1,2-trans-O-glycosides. However, the 1,2-orthoesters could be converted into the dioxolenium triflate and glycosyl triflate in the presence of TMSOTf, these intermediates which might be in equilibrium with the glycosyl oxocarbenium related species lead to the final mixture of the α/β-O-glycosides and side-products.
Mechanistic evaluation of MelA α-galactosidase from citrobacter freundii: A family 4 glycosyl hydrolase in which oxidation is rate-limiting
Chakladar, Saswati,Cheng, Lydia,Choi, Mary,Liu, James,Bennet, Andrew J.
experimental part, p. 4298 - 4308 (2012/03/22)
The MelA gene from Citrobacter freundii, which encodes a glycosyl hydrolase family 4 (GH4) α-galactosidase, has been cloned and expressed in Escherichia coli. The recombinant enzyme catalyzes the hydrolysis of phenyl α-galactosides via a redox elimination-addition mechanism involving oxidation of the hydroxyl group at C-3 and elimination of phenol across the C-1-C-2 bond to give an enzyme-bound glycal intermediate. For optimal activity, the MelA enzyme requires two cofactors, NAD+ and Mn2+, and the addition of a reducing agent, such as mercaptoethanol. To delineate the mechanism of action for this GH4 enzyme, we measured leaving group effects, and the derived βlg values on V and V/K are indistinguishable from zero (-0.01 ± 0.02 and 0.02 ± 0.04, respectively). Deuterium kinetic isotope effects (KIEs) were measured for the weakly activated substrate phenyl α-d-galactopyranoside in which isotopic substitution was incorporated at C-1, C-2, or C-3. KIEs of 1.06 ± 0.07, 0.91 ± 0.04, and 1.02 ± 0.06 were measured on V for the 1-2H, 2- 2H, and 3-2H isotopic substrates, respectively. The corresponding values on V/K were 1.13 ± 0.07, 1.74 ± 0.06, and 1.74 ± 0.05, respectively. To determine if the KIEs report on a single step or on a virtual transition state, we measured KIEs using doubly deuterated substrates. The measured DV/K KIEs for MelA-catalyzed hydrolysis of phenyl α-d-galactopyranoside on the dideuterated substrates, DV/K(3-D)/(2-D,3-D) and DV/K (2-D)/(2-D,3-D), are 1.71 ± 0.12 and 1.71 ± 0.13, respectively. In addition, the corresponding values on V, DV (3-D)/(2-D,3-D) and DV(2-D)/(2-D,3-D), are 0.91 ± 0.06 and 1.01 ± 0.06, respectively. These observations are consistent with oxidation at C-3, which occurs via the transfer of a hydride to the on-board NAD+, being concerted with proton removal at C-2 and the fact that this step is the first irreversible step for the MelA α-galactosidase-catalyzed reactions of aryl substrates. In addition, the rate-limiting step for Vmax must come after this irreversible step in the reaction mechanism.
Gold catalysis in glycosylation reactions
G?tze, Sebastian,Fitzner, Roland,Kunz, Horst
scheme or table, p. 3346 - 3348 (2010/03/04)
Glycosylation of alcohols containing acid-sensitive groups, as for example 1,2-5,6-di-O-isopropylidene-glucofuranose, Fmoc-threonine tert-butyl ester or farnesol, is achieved using gly-cosyl trichloroacetimidates activated by gold(I) chloride (5-10 mol%). While glycosylation with 2-O-acyl protected glycosyl donors proceeds with 1,2-trans-selectivity, non-neighboring group active glycosyldonors give mixtures of anomeric glycosides or -glycosides depending upon their structure and the reactivity of the glycosyl acceptor. Georg Thieme Verlag Stuttgart New York.
Stereoselective single-step synthesis and X-ray crystallographic investigation of acetylated aryl 1,2-trans glycopyranosides and aryl 1,2-cis C2-hydroxy-glycopyranosides
Aich, Udayanath,Loganathan, Duraikkannu
, p. 19 - 28 (2007/10/03)
Reported is an attractive and environmentally friendly method for the synthesis of the title compounds in moderate yield using inexpensive 1,2,3,4,6-penta-O-acetyl-β-d-gluco- and galactopyranoses as sugar donors, five different phenols as acceptors and H-β zeolite as the catalyst. The yield (23-28%) of aryl 3,4,6-tri-O-acetyl-α-d-glycopyranosides obtained in this single-step procedure is considerably higher than that obtained using previously reported methods. Treatment of an orthoacetate, 3,4,6-tri-O-acetyl- [1,2-O-(1-p-fluorophenoxyethylidene)]-α-d-glucopyranose, with p-fluorophenol under the same solvent-free reaction conditions also led to the formation of the title compounds in similar yield and composition. X-ray crystallographic analysis of phenyl 3,4,6-tri-O-acetyl-α-d-glucopyranoside and p-fluorophenyl 3,4,6-tri-O-acetyl-α-d-glucopyranoside showed that the molecular packing is stabilized by C-H...O, C-H...π and C-H...F interactions, in addition to regular hydrogen bonding patterns.
TEMPO-Mediated Regiospecific Oxidation of Glucosides to Glucuronides
Desai, Rakesh N.,Blackwell, Len F.
, p. 1981 - 1984 (2007/10/03)
A TEMPO/hypochlorite/bromide oxidant has been used for the conversion of aryl and steroidal glucosides to the corresponding glucuronide conjugates in good (48-74%) yield. An isoflavone glucoside failed to undergo this transformation.
Solid-liquid phase transfer catalyzed novel glycosylation reaction of phenols
Hongu, Mitsuya,Saito, Kunio,Tsujihara, Kenji
, p. 2775 - 2781 (2007/10/03)
A facile and mild glycosylation reaction in solid-liquid two-phase system (powdered K2CO3/CHCl3) containing phase transfer catalyst was found to be efficient for preparation of glucosides of 2', 6'-dihydroxyacetophenone (1) and other various substituted phenols.
Glycosylated prodrugs, their method of preparation and their uses
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, (2008/06/13)
Glycosylated prodrugs, a preparation method therefor, and their use with tumor-specific immunoenzymatic conjugates for the treatment of cancer, are described. These anthracycline prodrugs have formula (I). STR1
