- 1 -Ethyl-3-methylimidazolium ethylsulfate/copper catalyst for the enhancement of glucose chemiluminescent detection: Effects on light emission and enzyme activity
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The effect of the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate ([Emim][EtSO4]) on the copper-catalyzed luminol chemiluminescence (CL) is reported. A drastic light emission enhancement is observed, related to a strong interaction between Cu2+ and the imidazolium ring. In these conditions, the CL reaction was able to produce light efficiently at pH as low as 6.5 (amplification factor: Intensity+IL/Intensity-IL = 2900). Interesting effects of [Emim] [EtSO4] on the enzyme glucose oxidase activity were also evidenced, and advantages were taken from this enhancement to perform sensitive chemiluminescent glucose detection (LOD = 4 M) at pH 8.0.
- Santafe, Aurelie A.-M.,Doumeche, Bastian,Blum, Loic J.,Girard-Egrot, Agnes P.,Marquette, Christophe A.
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- MAOS of D-gluconic acid, D-glucono-1,4- and 1,5-lactones, esters, hydrazides, and benzimidazoles thereof
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Microwave-assisted organic synthesis (MAOS) of D-gluconic acid can be efficiently done by oxidation of D-glucose with bromine water, upon irradiation with microwave (MW). It was also used for the conversion of D-gluconic acid to ethyl D-gluconate, D-glucono-1,4- and 1,5-lactones, gluconyl hydrazide, and gluconyl phenylhydrazide in yields comparable to those obtained by conventional methods, but in much shorter times. A convenient microwave-mediated condensation of D-gluconic acid with o-phenylenediamines provided the respective acyclonucleoside benzimidazole in short time and good yield.
- El Ashry,Awad,Abdel Hamid,Atta
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- A NEW AND DIRECT ACCESS TO GLYCONO-1,4-LACTONES FROM GLYCOPYRANOSES BY REGIOSELECTIVE OXIDATION AND SUBSEQUENT RING RESTRICTION
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Treatment of partially protected or unprotected carbohydrates with the RhH(PPh3)4-benzalacetone system leads exclusively to glycono-1,4-lactones by regioselective oxidation and subsequent ring restriction.
- Isaac, Isabelle,Stasik, Imane,Beaupere, Daniel,Uzan, Raoul
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- Oxidation of D-glucose in the presence of 2,2′-bipyridine by Cr VI in aqueous micellar media: A kinetic study
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The kinetics of CrVI oxidation of d-glucose to the corresponding lactone in the presence and absence of 2,2′-bipyridine (bipy) has been carried out under the conditions, [d-glucose]T Gt; [Cr VI]T at different temperatures in aqueous micellar media. The monomeric CrVI species has been found to be kinetically active in the absence of bipy whereas in the bipy-catalysed path, the Cr VI-bipy complex has been found to be the active oxidant. In the bipy-catalysed path, the CrVI-bipy complex undergoes nucleophilic attack by the substrate to form a ternary complex. The ternary complex spontaneously experiences a redox decomposition (through two-electron transfer) in the rate-determining step leading to the product lactone and Cr IV-bipy complex. The CrIV-bipy complex then takes part in faster steps in the further oxidation of d-glucose and is ultimately converted into a CrIII-bipy complex. In the uncatalysed path, the Cr VI-substrate ester experiences acid catalysed redox decomposition (two-electron transfer) in the rate-determining step. The uncatalysed path shows a second order dependence on [H+] and a first order dependence on each of the reactants [d-glucose]T and [CrVI]T. In contrast, the bipy-catalysed path shows a first order dependence on each of the reactants [H+], [d-glucose]T and [Cr VI]T. The bipy-catalysed path is first order in [bipy]T. These observations remain unaltered in the presence of externally added surfactants. The effect of the cationic surfactant, N-cetylpyridinium chloride (CPC) and anionic surfactant, sodium dodecyl sulfate (SDS) on both the uncatalysed and bipy-catalysed path has been studied. CPC inhibits both the uncatalysed and bipy-catalysed path, while SDS catalyses these reactions. The observed micellar effects have been explained by considering hydrophobic and electrostatic interactions between the surfactants and reactants.
- Bayen, Ruhidas,Islam, Monirul,Saha, Bidyut,Das, Asim K.
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- Preparation method of D-gluconic acid-gamma-lactone and intermediate thereof
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The invention discloses a preparation method of D-gluconic acid-gamma-lactone and an intermediate thereof, and belongs to the technical field of pharmaceutical chemicals, and the method comprises thefollowing steps: reacting glucolactone serving as a starting material with a silane reagent under the condition of an alkaline reagent to obtain a high-purity solid D-gluconic acid-gamma-lactone intermediate; and then under the condition of acidity or fluoride, removing a silane protecting group to obtain the D-gluconic acid-gamma-lactone. The preparation method provided by the invention is cheapin required raw materials and reagents, low in cost, simple and safe to operate, high in yield, stable in yield, low in environmental pollution, good in economic effect and suitable for industrial production.
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Paragraph 0047-0065; 0069-0070; 0075
(2020/02/17)
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- Quantitative Determination of Pt- Catalyzed d -Glucose Oxidation Products Using 2D NMR
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Quantitative correlative 1H-13C NMR has long been discussed as a potential method for quantifying the components of complex reaction mixtures. Here, we show that quantitative HMBC NMR can be applied to understand the complexity of the catalytic oxidation of glucose to glucaric acid, which is a promising bio-derived precursor to adipic acid, under aqueous aerobic conditions. It is shown through 2D NMR analysis that the product streams of this increasingly studied reaction contain lactone and dilactone derivatives of acid products, including glucaric acid, which are not observable/quantifiable using traditional chromatographic techniques. At 98% glucose conversion, total C6 lactone yield reaches 44%. Furthermore, a study of catalyst stability shows that all Pt catalysts undergo product-mediated chemical leaching. Through catalyst development studies, it is shown that sequestration of leached Pt can be achieved through use of carbon supports.
- Armstrong,Hirayama,Knight,Hutchings
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p. 325 - 335
(2019/01/04)
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- SYNTHESIS OF ALDONOLACTONES, ALDAROLACTONES, AND ALDARODILACTONES USING GAS SPARGING
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Aldaric acids, aldonic acids, and their corresponding salts are cyclized to the corresponding lactone or dilactone using gas sparging to remove water.
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Page/Page column 14
(2008/06/13)
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- A new efficient access to glycono-1,4-lactones by oxidation of unprotected itols by catalytic hydrogen transfer with RhH(PPh3)4-benzalacetone system
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Treatment of unprotected pentitols and hexitols with RhH(PPh3)4-benzalacetone system leads exclusively to glycono-1,4-lactones in 60-96% yield.
- Isaac,Aizel,Stasik,Wadouachi,Beaupère
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p. 475 - 476
(2007/10/03)
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- 2-Acetamido-2-deoxyaldonolactones from sugar formazans
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A new approach towards simple aldonic acid derivatives starting from the corresponding aldoses via the 2-acetamido-2-deoxy formazans resulted in the synthesis of 2-acetamido-2-deoxy-D-galactono-1,4-lactone (8), and its 6-deoxy (11) and 6-azido-6-deoxy (14) analogues on treatment with trifluoroacetic acid.The five-membered ring structure of the lactones and that of the intermediate lactone phenylhydrazone (7) was proved by 1H and 13C NMR studies, including deuterium-induced differential isotope shift (DIS) measurements.With sodium borohydride, lactones 8 and 11 were converted into 2-acetamido-2-deoxy-D-galactitol (15) and its 6-deoxy analogue (17), respectively.
- Zsoldos-Mady, Virag,Pinter, Istvan,Neszmelyi, Andras,Messmer, Andras,Perczel, Andras
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- PHOTOINDUCED GENERATION OF GLYCOSYL CATIONS FROM THIOGLYCOSIDES
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Photochemically induced cleavage of thioaryl β-D-glucopyranosides using 1,4-dicyanonaphthalene as an electron-transfer agent, produces glycosyl cations potentially useful in glycosylation reactions.
- Griffin, Gary W.,Bandara, Nayanie C.,Clarke, Margaret A.,Tsang, Wing-Sum,Garegg, Per J.,et al.
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p. 939 - 947
(2007/10/02)
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- Decarbonylation of Unprotected Aldose Sugars by Chlorotris(triphenylphosphine)rhodium(I). A New Descent of Series Approach to Alditols, Deoxyalditols, and Glycosylalditols
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Unprotected Cn aldose sugars are cleanly decarbonylated by 1 equiv of chlorotris(triphenylphosphine)rhodium(I) in 1-24 h at 130 deg C in N-methyl-2-pyrrolidinone solution to give the corresponding Cn-1 alditol in about 75-95percent yields.This technique represents a useful variation on traditional carbohydrate "descent of series" reactions.The procedure is quite general and also works on a number of aldose derivatives, such as deoxy sugars, N-acetylated amino sugars, and disaccharides, providing convenient small-scale syntheses of deoxyalditols, (acetylamino)deoxyalditols, and glycosylalditols, respectively.The reactions proceed with complete retention of stereochemistry, the only side products observed being a few percent of the Cn lactones and the Cn-2 alditol.Attempts to make the reactions catalytic have not yet been very successful.
- Andrews, Mark A.,Gould, George L.,Klaeren, Stephen A.
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p. 5257 - 5264
(2007/10/02)
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- Metal-mediated decarbonylation and dehydration of ketose sugars
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Ketose sugars can be decarbonylated and/or dehydrated by the action of certain metal complexes. Fructose reacts with 1 equiv of RhCl(PPh3)3 (1) in N-methyl-2-pyrrolidinone (NMP) at 130°C to give furfuryl alcohol, Rh(CO)Cl(PPh3)2 (2), and a small amount of 1-deoxyerythritol. 1,3-Dihydroxyacetone consumes 2 equiv of 1, giving methane and ca. 2 mol of 2. With manno-2-heptulose the primary product is 2,7-anhydromanno-2-heptulopyranose. The mechanisms of these unusual reactions have been studied by using 13C-labeling experiments and model reactions employing Pd(II) and HCl. Attempts to make the reactions catalytic using [Rh(Ph2PCH2CH2CH2PPh 2)2]+[BF4]- in place of 1 were not successful. The use of NMP as a solvent offers some advantages in the acid-catalyzed synthesis of certain carbohydrate dehydration products, as exemplified by the conversion of manno-2-heptulose to its 2,7-anhydride and of 2-deoxyglucose to 1-(2-furanyl)-1,2-ethanediol.
- Andrews, Mark A.
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p. 2703 - 2708
(2008/10/08)
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- The chemistry of D-gluconic acid derivatives. Part II: the formation of (R)-O-isopropylideneglyceraldehyde from D-glucono-1,5-lactone
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Reaction of D-glucono-1,4-lactone, obtained from the 1,5-lactone by a modified procedure, with 2,2-dimethoxypropane-tin(II) chloride yields the corresponding 5,6-O-isopropylidene derivative.The preparation of the title compound from this acetal by periodate oxidation together with the characterisation of products and intermediates is described.
- Chittenden, Gordon J. F.
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p. 455 - 458
(2007/10/02)
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