Aldose
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Selective Axial-to-Equatorial Epimerization of Carbohydrates Open
Radical-mediated transformations have emerged as powerful methods for the synthesis of rare and unnatural branched, deoxygenated, and isomeric sugars. Here, we describe a radical-mediated axial-to-equatorial alcohol epimerization method to…
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Aldose to ketose interconversion: galactose and arabinose isomerization over heterogeneous catalysts Open
Isomerization of glucose, galactose and arabinose to corresponding keto-sugars was studied in the present work over a range of heterogeneous catalysts.
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Production of Hydroxyl–rich Acids from Xylose and Glucose Using Sn‐BEA Zeolite Open
Sn‐BEA zeolite is known to catalyze the aldose‐to‐ketose isomerization of xylose and glucose; however, the selectivity to pentose and hexose isomers is not stoichiometric, suggesting the formation of other products. In the present study, w…
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Critical approaches in the catalytic transformation of sugar isomerization and epimerization after Fischer－History, challenges, and prospects Open
The transformation of aldose to ketose or common sugars into rare saccharides, including rare ketoses and aldoses, is of great value and interest to the food industry and for saccharidic biomass utilization, medicine, and the synthesis of …
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Effects of Hydrolysis Condition and Detection Method on the Monosaccharide Composition Analysis of Polysaccharides from Natural Sources Open
Monosaccharide composition analysis is essential to the structural characterization and research into the biological activity of polysaccharides. In this study, a systematic comparison was performed among commonly used monosaccharide compo…
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X-ray structure of <i>Arthrobacter globiformis</i> M30 ketose 3-epimerase for the production of <span>D</span>-allulose from <span>D</span>-fructose Open
The X-ray structure of ketose 3-epimerase from Arthrobacter globiformis M30, which was previously reported to be a D-allulose 3-epimerase (AgD-AE), was determined at 1.96 Å resolution. The crystal belonged to the hexagonal space group P 6 …
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Reactivities Involved in the Seliwanoff Reaction Open
The Seliwanoff Reaction, a well-known colour reaction for ketoses, is based in the fact that ketoses are dehydrated more rapidly than aldoses to give a furfural derivative. Further condensation with resorcinol in dilute hydrochloric acid g…
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Efficient Alkaline Isomerization of Lactose to Lactulose in the Presence of an Organogermanium Compound Open
Lactulose, a disaccharide widely used in pharmaceuticals and functional foods, is produced by lactose isomerization. Lactose and lactulose have an aldose-ketose relationship. Less than 25 % conversion of lactose into lactulose is achieved …
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Synthetic Approaches to Phosphasugars (2-oxo-1,2-oxaphosphacyclanes) Using the Anomeric Alkoxyl Radical β-Fragmentation Reaction as the Key Step Open
The anomeric alkoxyl radical β-fragmentation (ARF) of carbohydrates possessing an electron-withdrawing group (EWG) at C2, promoted by PhI(OAc)2/I2, gives rise to an acyclic iodide through which a pentavalent atom of phosphorus can be intro…
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Coupling of anhydro-aldose tosylhydrazones with hydroxy compounds and carboxylic acids: a new route for the synthesis of C-β-<span>d</span>-glycopyranosylmethyl ethers and esters Open
Cross couplings of O-peracylated 2,6-anhydro-aldose tosylhydrazones (C-(β-D-glycopyranosyl)formaldehyde tosylhydrazones) with alcohols, phenols, and carboxylic acids were studied under thermic or photolytic conditions in the presence of K3…
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<i>C</i>‐Glycosyl Styrene Type Compounds by Pd‐Catalyzed Cross‐Coupling Reactions of Anhydro‐Aldose Tosylhydrazones with Benzyl Bromides Open
C ‐Glycopyranosyl styrene type compounds are valuable synthetic intermediates whose syntheses are known in rather lengthy procedures. Herein palladium‐catalyzed cross‐couplings of O ‐peracylated 2,6‐anhydro‐aldose tosylhydrazones with benz…
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H3PMo12O40 Immobilized on Amine Functionalized SBA-15 as a Catalyst for Aldose Epimerization Open
In this work various amount of phosphomolybdic acid (PMo) were immobilized on amine functionalized SBA-15 and used as heterogeneous catalysts in the epimerization of glucose in aqueous solution. 13.3PMo/NH2-SBA-15 exhibited the best cataly…
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The mechanism of a one-substrate transketolase reaction Open
Transketolase catalyzes the transfer of a glycolaldehyde residue from ketose (the donor substrate) to aldose (the acceptor substrate). In the absence of aldose, transketolase catalyzes a one-substrate reaction that involves only ketose. Th…
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Novel 2-phenoxypyrido[3,2-<i>b</i>]pyrazin-3(4<i>H</i>)-one derivatives as potent and selective aldose reductase inhibitors with antioxidant activity Open
To develop multifunctional aldose reductase (AKR1B1) inhibitors for anti-diabetic complications, a novel series of 2-phenoxypyrido[3,2-b]pyrazin-3(4H)-one derivatives were designed and synthesised. Most of the derivatives were found to be …
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A halotolerant aldose reductase from Debaryomyces nepalensis: gene isolation, overexpression and biochemical characterization Open
Aldose reductase (AR) catalyzes the conversion of aldoses to polyols, the natural sugar substitutes. Here we provide gene sequence and characteristics of the first-ever halotolerant AR which could be exploited as a potential biocatalyst.
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Formation of Three Selected AGEs and their Corresponding Intermediates in Aldose‐ and Ketose‐lysine Systems Open
Advanced Glycation End Products (AGEs) could be formed with α ‐dicarbonyl compounds as intermediates; however, simultaneous determination of AGES as well as their precursors and intermediates have rarely been mentioned, so as to investigat…
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The gas phase aldose‐ketone isomerization mechanism: Direct interconversion of the model hydroxycarbonyls 2‐hydroxypropanal and hydroxyacetone Open
We report a novel mechanism for the interconversion of 2-hydroxypropanal with its more-stable ketone isomer hydroxyacetone. Reaction proceeds via concerted transfer of two H atoms, requires a barrier of only ∼40 kcal mol−1, bypasses the en…
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A new synthesis of C-β-<span>d</span>-glycopyranosylmethyl sulfides by metal-free coupling of anhydro-aldose tosylhydrazones with thiols Open
Cross-coupling of anhydro-aldose tosylhydrazones with thiols provided a new access to C-glycopyranosylmethyl sulfides.
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Lactulose: Significance in Milk and Milk Products Open
Many kinds of lactose derivatives can be obtained using various methods, including epimerization, oxidation and reduction. Lactulose is not only utilized as an indicator substance for milk heat treatment but it also represents one of the m…
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Aminopolyols from Carbohydrates: Amination of Sugars and Sugar‐Derived Tetrahydrofurans with Transaminases Open
Carbohydrates are the major component of biomass and have unique potential as a sustainable source of building blocks for chemicals, materials, and biofuels because of their low cost, ready availability, and stereochemical diversity. With …
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SYNTHESIS AND EVALUATION OF SOME NEW 2-(5-(4-BENZAMIDOBENZYLIDENE)-2,4DIOXOTHIAZOLIDIN-3-YL)ACETIC ACID ANALOGS AS ALDOSE REDUCTASE INHIBITORS Open
Objective: Aldose reductase (ALR) enzyme plays a significant role in conversion of excess amount of glucose into sorbitol in diabetic condition,inhibitors of which decrease the secondary complication of diabetes mellitus. Scarce treatment …
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Synthesis and photoinitiated thiol–ene reactions of <i>exo</i>-mannals – a new route to <i>C</i>-β-<span>d</span>-mannosyl derivatives Open
A synthetic procedure was elaborated for O-peracylated exo-mannals. Thiol-ene additions to pyranoid and furanoid exo-mannals gave mannosylmethyl sulfide type adducts with exclusive regio- and β(d)-stereoselectivities including disaccharide…
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Synthesis of Benzyl Tetra-O-acetyl-α-L-glucopyranoside from Benzyl 2,3-Dideoxy-β-D-erythro-hex-2-enopyranoside Open
Benzyl tetra-O-acetyl--L-glucopyranoside was synthesized from benzyl 2,3-dideoxy--D-erythro-hex-2-enopyranoside in six steps and 19% overall yield.Epoxidation from the -side of the double bond between C-2 and C-3 of the starting material a…
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Coupling Reactions of Anhydro-Aldose Tosylhydrazones with Boronic Acids Open
A catalyst-free coupling reaction between O-peracetylated, O-perbenzoylated, O-permethylated, and O-permethoxymethylated 2,6-anhydro-aldose tosylhydrazones (C-(β-d-glycopyranosyl)formaldehyde tosylhydrazones) and aromatic boronic acids is …
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One step aqueous synthesis of unprotected glycosyl C-sulfonates Open
A one-step reaction for the production of unprotected glycosyl C-sulfonates directly from reducing sugars in aqueous solution has been developed, avoiding the use of any protecting groups. The reaction is equally applicable to disaccharide…
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COMPARISON OF REDUCING SUGARS AS AGENT TO RETARD CORROSION RATES Open
This study reports the effect of adding sugars to prevent the corrosion of reinforcing bars.Various types of sugars, including reducing sugar aldose (sugar with an aldehyde group), ketose (sugar with a ketone group), and syrup with an expi…
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An Organogermanium Compound Enhances the Initial Reaction Rate of Alkaline Isomerization of an Aldose into a Ketose through Enediol Complex Formation Open
We previously demonstrated that the organogermanium compound 3-(trihydroxygermyl)propanoic acid (THGP) enhances the enzymatic and alkaline isomerization of an aldose to a ketose through cis-diol complex formation by multiple mechanisms. It…
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Synthesis and Aldose Reductase Inhibitory Activity of Botryllazine A Derivatives Open
Aldose reductase (AR) is associated with the onset of diabetic complications. Botryllazine A and its analogues were synthesized and evaluated for human AR inhibitory activity. Analogues possessing aromatic bicyclic systems at the C5 positi…
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Enzymatic Upgrading of Biomass‐Derived Aldoses to Rare Deoxy Ketoses Catalyzed by Transketolase Variants Open
A sustainable, convenient, scalable, one‐step method for the two‐carbon chain elongation of cheap and biomass‐derived pentoses ( l ‐arabinose, and 2‐deoxy‐ d ‐ribose) and hexose l ‐rhamnose was developed to produce C n+2 deoxy ketoses (C‐7…
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Rare Ketose Synthesis from Glycolaldehyde by C2 Elongation of Aldoses Catalyzed by Transketolase Variants Open
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