A 11b and 13c nmr determination of the structures of borate complexes of pentoses and related sugars

Chapelle, Stella; Verchère, Jean‐François

doi:10.1016/s0040-4020(01)86149-4

Cited by 129 publications

(65 citation statements)

References 20 publications

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“…The syntheses of 2-APB, [24] 3-APB [25] and 4-APB [15] have been reported previously. For each compound the 1 H NMR 13 C NMR, 11 B NMR and MS data obtained was consistent with that published.…”

Section: Methodsmentioning

confidence: 97%

Complexation of L‐Lactate with Boronic Acids: A Solution and Holographic Analysis

Sartain

Yang

Lowe

2008

Chemistry A European J

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Boronic acids have been used as receptors for the detection of diols and alpha-hydroxy acids. The incorporation of 3-acrylamide phenyl boronic acid (3-APB) into a hydrogel generates a suitably responsive and fully reversible holographic sensor for L-lactate. However, it was also found that the use of 3-APB resulted in the sensor being responsive towards a number of other compounds containing two hydroxy groups. This report details the further investigation into the reaction between L-lactate and three boronic acid-based receptors, both in the holograms and in solution, in order to establish the mechanism of binding. A novel boronate receptor is proposed based on this understanding.

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Section: Methodsmentioning

confidence: 97%

Complexation of L‐Lactate with Boronic Acids: A Solution and Holographic Analysis

Sartain

Yang

Lowe

2008

Chemistry A European J

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“…It is well known that carbohydrates form stable chelate complexes with boric acid [19][20][21] of the form shown in Scheme 2 and catalyze the isomerization of aldohexoses to ketohexoses in aqueous basic environment. [22,23] Abstract: The dehydration of glucose and other hexose carbohydrates to 5-(hydroxymethyl)furfural (HMF) was investigated in imidazolium-based ionic liquids with boric acid as a promoter.…”

Section: Introductionmentioning

confidence: 99%

Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter

Ståhlberg

Rodríguez-Rodríguez

Fristrup

et al. 2011

Chemistry A European J

192

139

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The dehydration of glucose and other hexose carbohydrates to 5-(hydroxymethyl)furfural (HMF) was investigated in imidazolium-based ionic liquids with boric acid as a promoter. A yield of up to 42% from glucose and as much as 66% from sucrose was obtained. The yield of HMF decreased as the concentration of boric acid exceeded one equivalent, most likely as a consequence of stronger fructose-borate chelate complexes being formed. Computational modeling with DFT calculations confirmed that the formation of 1:1 glucose-borate complexes facilitated the conversion pathway from glucose to fructose. Deuterium-labeling studies elucidated that the isomerization proceeded via an ene-diol mechanism, which is different to that of the enzyme-catalyzed isomerization of glucose to fructose. The introduced non-metal system containing boric acid provides a new direction in the search for catalyst systems allowing efficient HMF formation from biorenewable sources.

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“…LuxS cleaves the intermediate S-ribosylhomocysteine into homocysteine and (S)-4,5-dihydroxy-2,3-pentanedione [(S)-DPD, 1], the metabolic precursor of AI-2. [4] Through the processes of cyclization (2,3), hydration (4,5,10,11), and borate ester formation if enough borate is present in solution (6)(7)(8)(9), [5] DPD exists as an equilibrium mixture of several compounds (Scheme 1), some of which function as signaling molecules.…”

Section: Introductionmentioning

confidence: 99%

Identification, Quantification, and Determination of the Absolute Configuration of the Bacterial Quorum‐Sensing Signal Autoinducer‐2 by Gas Chromatography–Mass Spectrometry

et al. 2009

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SENSING THE SIGNAL: A gas chromatography-mass spectrometry (GC-MS) method for the analysis of the quorum-sensing autoinducer-2 is described. It allows, for the first time, the direct analysis and accurate determination of this highly water soluble signaling compound, which exists in complex equilibria. The application on the caries-causing bacterium Streptococcus mutans is described. Autoinducer-2 (AI-2) is an important, small extracellular signaling molecule that is used by many bacteria. It is part of the AI-2 pool, a group of equilibrium-connected compounds derived from (S)-4,5-dihydroxy-2,3-pentanedione [(S)-DPD, 1]. Currently, these compounds are analyzed by indirect methods relying on the luminescence of sensor strains, the fluorescence of receptor proteins modified with fluorophores, or by isolation procedures not practical for quantitative analysis. Herein, we report a direct analytical procedure that allows for the unambiguous identification and quantification of molecular species by mass spectrometry. Phenylenediamine reacts readily and quantitatively with 1 to form the quinoxalinediol 12 under aqueous conditions. The extraction and silylation of this compound results in the formation of a silyl ether (13), which is amenable for analysis by gas chromatography-mass spectrometry. The use of an isotopically labeled variant (16) of 12 as an internal standard opens the possibility for the accurate quantification of samples containing AI-2 or its equilibrium products. The analysis of cell-free culture supernatants of Vibrio harveyi and Streptococcus mutans allowed for the accurate quantification of the AI-2 concentration above the limit of detection (0.7 ng mL(-1)). No compounds were detected in mutants lacking the capability to produce AI-2. In addition, the absolute configuration of 1 can be analyzed using the derivative 13 by chiral gas chromatography.

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A 11b and 13c nmr determination of the structures of borate complexes of pentoses and related sugars

Cited by 129 publications

References 20 publications

Complexation of L‐Lactate with Boronic Acids: A Solution and Holographic Analysis

Complexation of L‐Lactate with Boronic Acids: A Solution and Holographic Analysis

Metal‐Free Dehydration of Glucose to 5‐(Hydroxymethyl)furfural in Ionic Liquids with Boric Acid as a Promoter

Identification, Quantification, and Determination of the Absolute Configuration of the Bacterial Quorum‐Sensing Signal Autoinducer‐2 by Gas Chromatography–Mass Spectrometry

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