- Expanding the scope of laccase-mediator systems
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The laccase-mediator system (LMS) for the regeneration of oxidised nicotinamide co-factors was revisited to broaden the mediator scope. Among the 18 mediators screened, acetosyringone, syringaldehyde and caffeic acid excelled with respect to activity and stability under process conditions. The LMS based on the laccase from Myceliophthora thermophila and acetosyringone was further investigated and applied to promote the nicotinamide adenine dinucleotide (NAD+)-dependent oxidation of glucose as well as the oxidative lactonisation of 1,4-butanediol to the corresponding γ-butyrolactone. Laccase gets a look-in: The laccase-mediator system (LMS) for the regeneration of oxidized nicotinamide co-factors is revisited to broaden the mediator scope. The LMS based on the laccase from Myceliophthora thermophila and acetosyringone is applied to promote the oxidation of glucose and the oxidative lactonization of 1,4-butanediol to the corresponding γ-butyrolactone.
- Koenst, Paul,Kara, Selin,Kochius, Svenja,Holtmann, Dirk,Arends, Isabel W. C. E.,Ludwig, Roland,Hollmann, Frank
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- Aerobic oxidation of glucose over gold nanoparticles deposited on cellulose
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Gold nanoparticles (NPs) with mean diameters of around 2 nm could be deposited directly onto a bio-polymer, cellulose, by the solid grinding method with volatile dimethyl Au(III)acetylacetonate followed by the reduction with H2. Gold NPs on cellulose showed appreciably high catalytic activity with a turnover frequency (TOF) of 11 s-1 for the aerobic oxidation of glucose to produce sodium gluconate at 60 °C and at pH 9.5. The catalytic activity of Au/cellulose was comparable to that of Au/C provided the size of the Au particles was similar.
- Ishida, Tamao,Watanabe, Hiroto,Bebeko, Takao,Akita, Tomoki,Haruta, Masatake
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- Nonenzymatic and metal-free organocatalysis for in situ regeneration of oxidized cofactors by activation and reduction of molecular oxygen
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The application of synthetic flavinium organocatalysts for the in situ regeneration of oxidized cofactors NAD(P)+ using O2 as the terminal oxidant without any special illumination or equipment is reported. With the aid of the highly active bridged flavinium catalyst, the rate of NAD(P)H oxidation is accelerated by 3 orders of magnitude. The results show that the catalytic activity of the bridged flavinium catalyst is not dependent on light but on only oxygen. Furthermore, this catalyst is compatible with various preparative enzymatic oxidation reactions. A hydride transfer mechanism is proposed for the presented system.
- Zhu, Chenjie,Li, Qing,Pu, Lingling,Tan, Zhuotao,Guo, Kai,Ying, Hanjie,Ouyang, Pingkai
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- Efficient Oxidation of Glucose into Sodium Gluconate Catalyzed by Hydroxyapatite Supported Au Catalyst
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Abstract: Gold nanoparticles (NPs) with mean diameters of around 2?nm were successfully deposited onto the inorganic support hydroxyapatite to give the Au/HAP catalyst. The Au/HAP catalyst showed appreciably high catalytic activity for the aerobic oxidation of glucose to produce sodium gluconate at room temperature. Glucose conversions of 100% and sodium gluconate yield of 90.9% were achieved after 1?h at room temperature by the use of 0.5 equiv. Na2CO3. The developed catalytic system was easily-handed for the production of sodium gluconate. In addition, the Au/HAP catalyst was stable and could be reused for several times without the loss of its catalytic activity. Graphical Abstract: Au/HAP catalyst showed high activity and stability on the aerobic oxidation of glucose. [Figure not available: see fulltext.]
- Liu, Xianxiang,Yang, Yongjun,Su, Shengpei,Yin, Dulin
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- Gold Catalysis and Photoactivation: A Fast and Selective Procedure for the Oxidation of Free Sugars
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A fast and efficient methodology for the selective oxidation of sugars into corresponding sodium aldonates is herein reported. Hydrogen peroxide was used as a cheap oxidant and electron scavenger, in the presence of only 0.003-0.006 mol % of gold in basic conditions. Three photocatalysts were studied, namely Au/Al2O3, Au/TiO2, and Au/CeO2, the latter being the most efficient (TOF > 750 000 h-1) and perfectly selective. Only a 10 min exposition under standard incident sunlight irradiation (A.M.1.5G conditions, 100 mW/cm2) affords total conversion of glucose into the corresponding sodium gluconate. Demonstrating its versatility, this methodology was successfully applied to a variety of oligosaccharides leading to the corresponding aldonates in quantitative yield and high purity (>95%) without any purification step. The photocatalyst was recovered by simple filtration and reused 5 times leading to the same conversion and selectivity after 10 min of illumination.
- Omri, Mehdi,Sauvage, Frédéric,Busby, Yan,Becuwe, Matthieu,Pourceau, Gwladys,Wadouachi, Anne
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- Crystal and molecular structure of N-(n-octyl)-6-deoxy-D-gluconamide: a novel packing of amphiphilic molecules
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N-(n-octyl)-6-deoxy-D-gluconamide crystallizes in the orthorhombic space group P212121, with a = 5.4524(5), b = 16.662(3), and c = 36.897(5) Angstroem.The structure was determined by X-ray diffraction and refined to R = 9.2percent.The asymmetric crystal unit contains two molecules (A, B) with significantly different conformations.In contrast to the crystal structures of the N-(n-alkyl)-D-gluconamide family, in which the molecules were found arranged in head-to-tail monolayers, molecules A and B form a complex motif with pairwise alternating orientations andinterdigitating antiparallel aliphatic chains.The two symmetry independent molecules form considerably different hydrogen bond patterns.Keywords: Alkyl-gluconamides; Amphiphilic molecules; Aliphatic chain packing; Crystal packing; Hydrogen bonding
- Herbst, Roswitha,Steiner, Thomas,Pfannemueller, Beate,Saenger, Wolfram
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- Effect of reduction method on the performance of Pd catalysts supported on activated carbon for the selective oxidation of glucose
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The effect of the reduction method on the catalytic properties of palladium catalysts supported on activated carbon for the oxidation of D-glucose was examined. The reduction methods investigated include argon glow discharge plasma reduction at room temperature, reduction by flowing hydrogen at elevated temperature, and reduction by formaldehyde at room temperature. The plasma-reduced catalyst shows the smallest metal particles with a narrow size distribution that leads to a much higher activity. The catalyst characteristics show that the plasma reduction increases the amount of oxygen-containing functional groups, which significantly enhances the hydrophilic property of the activated carbon and improves the dispersion of the metal.
- Chen, Kangcheng,Pan, Yunxiang,Liu, Changjun
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- TEMPO-mediated oxidation of maltodextrins and D-glucose: Effect of pH on the selectivity and sequestering ability of the resulting polycarboxylates
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Maltodextrins were oxidized to polyglucuronic acids with the ternary oxidation system: NaOCl-NaBr-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). The chemoselective oxidation at the primary alcohol groups was shown to be strongly pH dependent. Oxidation of
- Thaburet, Jean-Francois,Merbouh, Nabyl,Ibert, Mathias,Marsais, Francis,Queguiner, Guy
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- C1 Oxidation/C2 Reduction Isomerization of Unprotected Aldoses Induced by Light/Ketone
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Unprotected aldoses in water undergo an isomerization reaction via a radical pathway when irradiated with light in the presence of water-soluble benzophenone. Whereas its anomeric carbon (C1) is oxidized to a carboxy group, the hydroxy group on the C2 carbon is replaced by hydrogen. The generated 2-deoxy lactones are readily reduced to the corresponding 2-deoxy aldoses, which are often contained in bioactive compounds.
- Masuda, Yusuke,Tsuda, Hiromu,Murakami, Masahiro
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supporting information
p. 2755 - 2759
(2020/01/25)
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- Efficient and Bio-inspired Conversion of Cellulose to Formic Acid Catalyzed by Metalloporphyrins in Alkaline Solution
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A bio-inspired approach for efficient conversion of cellulose to formic acid (FA) was developed in an aqueous alkaline medium. Metalloporphyrins mimicking cytochrome P450 exhibit efficiently and selectively catalytic performance in catalytic conversion of cellulose. High yield of FA about 63.7% was obtained by using sulfonated iron(III) porphyrin as the catalyst and O2 as the oxidant. Iron(III)-peroxo species, TSPPFeIIIOO?, was involved to cleave the C-C bonds of gluconic acid to FA in this catalytic system. This approach used relatively high concentration of cellulose and ppm concentration of catalyst. This work may provide a bio-inspired route to efficient conversion of cellulose to FA.
- Liu, Qiang,Zhou, Doudou,Li, Zongxiang,Luo, Weiping,Guo, Cancheng
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supporting information
p. 1063 - 1068
(2017/07/24)
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- Method for preparing sodium gluconate through catalytically oxidating glucose by carbon loading type transition-metal catalyst
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The invention discloses a method for preparing sodium gluconate through catalytically oxidating glucose by a carbon loading type transition-metal catalyst. The method comprises the specific steps of thoroughly mixing an X/C catalyst and an aqueous solution of the glucose, controlling the reaction temperature to 45 DEG C to 65 DEG C, continuously introducing oxygen gas into a mixture system during reaction, adding a 30% (mass concentration) NaOH aqueous solution into the mixture system with stirring, maintaining the pH value of the reaction system to 7.5 to 9.0, carrying out an isothermal reaction until the pH value of the system remains constant in 30 minutes, subjecting the obtained solution to standing and filtrating so as to separate out the catalyst for reuse, and subjecting the filtrate to concentrating, crystallizing and air-drying treatment, thereby obtaining the product, i.e., sodium gluconate, wherein in the X/C catalyst, X is a main active ingredient and is one or two selected from Co, Ag, Cu and Ni, the atomic ratio of the X to activated carbon is 1: (2.5 to 10), C is a carrier and is pretreated activated carbon which has the specific surface area of 500m/g to 2,000m/g. According to the method, the production process is simple, the product is easy to separate, the catalyst is low in cost and easy to regenerate and can be recycled, and no waste gases, waste water and waste residues is discharged.
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Paragraph 0013-0014
(2017/06/02)
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- Method for preparing sodium gluconate through carbon-loaded multielement noble metal catalyst catalytic oxidation of glucose
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The invention discloses a method for preparing sodium gluconate through carbon-loaded multielement noble metal catalyst catalytic oxidation of glucose. The method comprises fully mixing a Pd-X/C catalyst and a glucose aqueous solution, carrying out a thermostatic reaction process under conditions of a reaction temperature of 45-65 DEG C, continuous feeding of oxygen into the mixture system in the reaction, addition of a NaOH aqueous solution along with stirring and reaction system pH of 7.5-9.0 until the system pH is constant in 30min, standing the reaction solution, filtering the precipitated catalyst for reuse and carrying out condensation, crystallization and air drying on the filtrate to obtain sodium gluconate. The Pd-X/C catalyst comprises Pd as a main active ingredient and has granularity of 2-20nm. A mass ratio of Pd to activated carbon is 0.25-2: 100. X represents other active ingredients selected from Mo, Co, Fe, Ag, Bi, Cu and Ni. An atomic ratio of X to Pd is 0.1-1: 1. Pretreated activated carbon is used as a catalyst carrier and has a specific surface area of 500-2000 m/g. The method is simple. The product can be easily separated. The catalyst does not lose activity after long-term recycling.
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Paragraph 0014
(2017/06/03)
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- A method for producing sodium gluconate
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The invention relates to a production method of sodium gluconate, the method is as follows: using a glucose solution or a mother liquid for production of crystalline glucose, as a raw material, using activated carbon as a catalyst, using ozone for oxidation in a gas-liquid-solid three phase reactor to produce the sodium gluconate. Compared with traditional noble metal catalysts, the catalyst used in the method greatly reduces the cost and may not deactivate; the ozone oxidation reaction is high in speed and high in efficiency; the catalyst is free of pollution, so that the mother liquid for production of the crystalline glucose can be used as the raw material to produce the sodium gluconate, the product quality is high, resources are saved, the efficiency is improved, and the production process is free of waste discharge.
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Paragraph 0036-0037
(2017/02/09)
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- Highly efficient room-temperature oxidation of cyclohexene and d-glucose over nanogold Au/SiO2 in water
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Silica-supported nanogold catalysts suspended in 30% hydrogen peroxide using ultrasound are highly active and selective for cyclohexene and d-glucose oxidation at room temperature. In these conditions a polar reactant, D-glucose, can be efficiently and directly converted with 100% yield using this system, while a conversion of apolar cyclohexene is limited by the addition of a surfactant improving cosolubility in the system and/or catalyst/support wettability. To our best knowledge this is the first time that hydrogen peroxide has been used efficiently in association with a gold catalyst for the selective oxidation of cyclohexene in a biphasic system.
- Bujak, Piotr,Bartczak, Piotr,Polanski, Jaroslaw
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- Iron catalysis for in situ regeneration of oxidized cofactors by activation and reduction of molecular oxygen: A synthetic metalloporphyrin as a biomimetic NAD(P)H oxidase
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(Figure Presented) An enzyme substitute: A synthetic FeIII porphyrin was used as a catalyst for the activation and reduction of O 2 into H2O with the cofactor NAD(P)H in aqueous solution. The catalyst is compatible with different preparative enzymatic oxidation reactions. Thus, a new method is provided for the in situ regeneration of the oxidized cofactor NAD(P)+ with help from a nonenzymatic, synthetic catalyst (see scheme).
- Maid, Harald,Boehm, Philipp,Huber, Stefan M.,Bauer, Walter,Hummel, Werner,Jux, Norbert,Groeger, Harald
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supporting information; experimental part
p. 2397 - 2400
(2011/04/22)
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- Facile nitroxide-mediated oxidations of D-glucose to D-glucaric acid
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The oxidation of D-(+)-glucose to D-glucaric acid using the TEMPO-like nitroxide oxidation catalyst, 4-acetamido-2,2,6,6-tetramethyl-1-piperidinyloxy (4-acetamido-TEMPO) was carried out using several oxidizing agents and co-catalyst. The pH and temperature of the reactions were closely monitored to decrease degradations during the oxidation, and several isolation methods were explored.
- Merbouh, Nabyl,Francois Thaburet, Jean,Ibert, Mathias,Marsais, Francis,Bobbitt, James M
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- Catalytic Oxidation of Glucose on Bismuth-Promoted Palladium Catalysts
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Water solutions of glucose (1.66 mol liter-1) were oxidized with air at 313 K on palladium catalysts supported on active charcoal.High gluconate yields (99.3percent) were obtained in the presence of bismuth-promoted catalysis.Bismuth was deposited via a surface redox reaction on Pd/C catalysts containing 1- to 2-nm Pd particles.A STEM-EDX study showed that bismuth atoms are selectively and homogeneously deposited on the palladium particles.The catalyst can be recycled without loss of activity and selectivity.Bismuth was not leached from the catalyst during reaction and recycling.Bismuth adatoms prevent oxygen poisoning of the palladium surface by acting as a co-catalyst in the oxidative dehydrogenation mechanism.It was determined by calorimetric measurements that oxygen should adsorb preferentially on bismuth rather than on palladium.
- Besson, Michele,Lahmer, Faousy,Gallezot, Pierre,Fuertes, Patrick,Fleche, Guy
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p. 116 - 121
(2007/10/02)
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- THE EFFECT OF BROMIDE IONS ON THE KINETICS OF THE ELECTROCHEMICAL PROCESS OF GLUCOSE OXIDATION
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Chronovoltammetric investigations on the kinetics of the electrochemical oxidation of glucose in NaHCO3 aqueous solutions have shown an inhibiting effect of bromide ions on the rate of this process resulting from their adsorption on the anode surface.
- Jankiewicz, Barbara,Soloniewicz, Rajmund,Teodorczyk, Maria
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p. 665 - 674
(2007/10/02)
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- Process for producing gluconic acid
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Gluconic acid is produced by oxidizing glucose with an oxygen-containing gas in an aqueous alkali solution in the presence of a palladium-bismuth/carbon catalyst which has adsorbed firstly bismuth and secondly palladium. The catalyst has an improved activity, selectivity and durability.
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- Depilating composition and method
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A composition for removing hair from full hair whole carcasses, skins, hides and pelts comprising: ______________________________________ Approx. Wt. (%)______________________________________Water 78.00-94.00Sodium Hydroxide 2.00-6.00Sodium Gluconate 0.10-0.50Trisodium Phosphate 1.00-3.00Triethanolamine Lauryl Sulfate 0.50-2.00Cocodiethanolamide 0.05-0.10Sodium Metasilicate 0.50-0.20Sodium Thioglycolate 0.45-5.00Triethonolamine Dodecyl Benzene 0.50-1.50SulfonateCalcium Hydroxide 1.00-4.00______________________________________
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- Platinum(II) complexes
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Platinum(II) complexes comprising platinum(II), a diamine, a ligand of D-gluconic acid and an inorganic or organic anion or ligand, and effecting superior antineoplastic activity at a smaller dose.
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