- Catalytic wet air oxidation of D-glucose by perovskite type oxides (Fe, Co, Mn) for the synthesis of value-added chemicals
-
The conversion of common biomasses derived, as D-glucose, into value-added chemicals has received highest attention in the last few years. Among all processes, the catalytic wet air oxidation (CWAO) of derived biomasses using noble metal-based heterogeneo
- Geobaldo, Francesco,Pirone, Raffaele,Russo, Nunzio,Scelfo, Simone
-
-
- Boosting electrocatalytic nitrogen fixation: Via energy-efficient anodic oxidation of sodium gluconate
-
Here, we report an anodic replacement of the water oxidation reaction with more readily oxidizable species to facilitate ambient electrocatalytic nitrogen reduction reaction (NRR). A self-supported catalyst, CuII-MOF on carbon cloth (JUC-1000/CC), acts as a versatile cathode and anode for both NRR and electro-oxidation of sodium gluconate to glucaric acid. Impressively, the two-electrode system requires a potential of only 0.4 V to achieve an NH3 yield rate of 24.7 μg h-1 mgcat-1, an FE of 11.90% and an SA selectivity of 96.96%, and shows strong electrochemical stability. This study reveals that the strategy avoids the sacrifice of the NH3 yield to increase FE, and offers an efficient and simultaneous electrosynthesis of NH3 and SA.
- Zhao, Lu,Kuang, Xuan,Chen, Cheng,Sun, Xu,Wang, Zhiling,Wei, Qin
-
supporting information
p. 10170 - 10173
(2019/08/30)
-
- Efficient Bioconversion of Sucrose to High-Value-Added Glucaric Acid by In Vitro Metabolic Engineering
-
Glucaric acid (GA) is a major value-added chemicals feedstock and additive, especially in the food, cosmetics, and pharmaceutical industries. The increasing demand for GA is driving the search for a more efficient and less costly production pathway. In this study, a new in vitro multi-enzyme cascade system was developed, which converts sucrose efficiently to GA in a single vessel. The in vitro system, which does not require adenosine triphosphate (ATP) or nicotinamide adenine dinucleotide (NAD+) supplementation, contains seven enzymes. All enzymes were chosen from the BRENDA and NCBI databases and were expressed efficiently in Escherichia coli BL21(DE3). All seven enzymes were combined in an in vitro cascade system, and the reaction conditions were optimized. Under the optimized conditions, the in vitro seven-enzyme cascade system converted 50 mm sucrose to 34.8 mm GA with high efficiency (75 % of the theoretical yield). This system represents an alternative pathway for more efficient and less costly production of GA, which could be adapted for the synthesis of other value-added chemicals.
- Su, Hui-Hui,Guo, Ze-Wang,Wu, Xiao-Ling,Xu, Pei,Li, Ning,Zong, Min-Hua,Lou, Wen-Yong
-
p. 2278 - 2285
(2019/04/17)
-
- Enhanced photocatalytic performance for oxidation of glucose to value-added organic acids in water using iron thioporphyrazine modified SnO2
-
The selective conversion of glucose into value-added chemicals in the presence of only water is a challenging topic. In this work, selective photocatalytic oxidation of glucose in water was studied using iron thioporphyrazine modified SnO2 (SnO2/FePz(SBu)8) as the catalyst and atmospheric air as the oxidant under simulated sunlight irradiation. It was found that value-added organic acids including glucaric acid, gluconic acid and formic acid could be obtained from the oxidation of glucose under such conditions. The effects of the FePz(SBu)8 content, glucose concentration and additional addition on the conversion of glucose and the selectivity of the organic acids were further explored. Under the optimized conditions, the total selectivity for the organic acids on the SnO2/FePz(SBu)8 photocatalyst reached up to 52.2% at 34.2% glucose conversion. More importantly, it has been demonstrated that the presence of FePz(SBu)8 on the surface of SnO2 can keep the selectivity of the organic acids unchanged under conditions of increasing the glucose conversion. To illustrate the synergistic effect for the enhanced photocatalytic activity between FePz(SBu)8 and SnO2, surface photocurrent, electron spin resonance (ESR) spectra and adsorption behavior experiments were carried out on pure SnO2 and SnO2/FePz(SBu)8. It was found that the introduction of FePz(SBu)8 could enhance the separation of photogenerated charge, promote the generation of active species for photocatalysis and improve the adsorption capacity of glucose, which are beneficial to the enhancement of photocatalytic activity. Additionally, a possible pathway of glucose oxidation was proposed through both detailed analysis of the oxidation intermediate of glucose and comparative experiments with different organic acids as the substrates, indicating that the formation of organic acids were fulfilled by two parallel and subsequent reactions at the beginning of the reaction.
- Zhang, Quanquan,Ge, Yanchun,Yang, Changjun,Zhang, Bingguang,Deng, Kejian
-
supporting information
p. 5019 - 5029
(2019/09/30)
-
- Quantitative Determination of Pt- Catalyzed d -Glucose Oxidation Products Using 2D NMR
-
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
-
p. 325 - 335
(2019/01/04)
-
- Visible-light-driven selective oxidation of glucose in water with H-ZSM-5 zeolite supported biomimetic photocatalyst
-
A new iron tetra(2,3-bis(butylthio)maleonitrile)porphyrazine (FePz(SBu)8)has been synthesized, then it was loaded on H-ZSM-5 zeolite to obtain a supported biomimetic photocatalyst H-ZSM-5/FePz(SBu)8. Using H2O2 as oxidant, the photocatalytic selective oxidation of glucose in water under visible light (λ ≥ 420 nm)irradiation was carried out in presence of H-ZSM-5/FePz(SBu)8. Under such conditions, the glucose can be efficiently converted into value-added chemicals such as glucaric acid, gluconic acid, arabinose, glycerol and formic acid. More importantly, in comparison with pure FePz(SBu)8 and pure H-ZSM-5 zeolite, the H-ZSM-5/FePz(SBu)8 exhibited a higher photocatalytic activity for glucose oxidation and the formation of glucaric acid was observed only when H-ZSM-5/FePz(SBu)8 was used, deriving from the synergistic effect between FePz(SBu)8 and H-ZSM-5 zeolite. Some reaction parameters of glucose oxidation catalyzed by the H-ZSM-5/FePz(SBu)8 were discussed, such as loading amount of FePz(SBu)8, H2O2:glucose ratio, glucose concentration, and so on. It was demonstrated that the Soret-band of FePz(SBu)8 contributed more to the visible light photocatalytic activity than the Q-band during the photocatalytic process. The stability of H-ZSM-5/FePz(SBu)8 during the photocatalytic process was further evaluated by the reusability test. In addition, the generation of reactive oxygen species was determined by electron spin resonance (ESR)technology and scavenger experiments. A possible reaction pathway of glucose oxidation was also discussed.
- Chen, Rui,Yang, Changjun,Zhang, Quanquan,Zhang, Bingguang,Deng, Kejian
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p. 297 - 305
(2019/05/24)
-
- POROUS SHAPED METAL-CARBON PRODUCTS
-
The present invention provides a porous metal-containing carbon-based material that is stable at high temperatures under aqueous conditions. The porous metal-containing carbon-based materials are particularly useful in catalytic applications. Also provided, are methods for making and using porous shaped metal-carbon products prepared from these materials.
- -
-
Paragraph 0242
(2017/05/17)
-
- Oxidation of d-Glucose to Glucaric Acid Using Au/C Catalysts
-
The reactivity of Au and AuBi nanoparticles supported on activated carbon AC was investigated in the direct oxidation of glucose to glucaric acid. The catalysts were very active, regardless of the Au nanoparticles size, but the catalyst with the smallest average particle diameter was the least selective to glucaric acid because of the enhanced consecutive oxidative degradation of the intermediately formed gluconic acid. The reaction network included the fast oxidation of glucose to gluconic acid, which was the only primary product, and its consecutive oxidation into either glucaric acid or lighter mono and dicarboxylic acids. The best glucaric acid yield obtained with a AuBi/AC catalyst (Au/Bi 3:1) was 31 %, with 18 % residual gluconic acid. The control of reaction parameters was essential to achieving the best selectivity. Specifically, the glucose concentration turned out to be a critical parameter in relation to O2 pressure and to glucose/metal ratio.
- Solmi, Stefania,Morreale, Calogero,Ospitali, Francesca,Agnoli, Stefano,Cavani, Fabrizio
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p. 2797 - 2806
(2017/07/28)
-
- SHAPED POROUS CARBON PRODUCTS
-
Shaped porous carbon products and processes for preparing these products are provided. The shaped porous carbon products can be used, for example, as catalyst supports and adsorbents. Catalyst compositions including these shaped porous carbon products, processes of preparing the catalyst compositions, and various processes of using the shaped porous carbon products and catalyst compositions are also provided.
- -
-
Paragraph 0327-0328
(2017/05/21)
-
- Pt catalysts for efficient aerobic oxidation of glucose to glucaric acid in water
-
Glucaric acid, a promising bio-based chemical for the production of adipic acid, is produced on a commercial Pt/C catalyst via aerobic oxidation of glucose in water. Facile oxidation of gluconic acid, an intermediate oxidation product of glucose, under optimal conditions of an initial pH of 7.2, 80 °C, 13.8 bar O2 and a glucose/Pt molar ratio of 54, enabled a maximum glucaric acid yield of 74%, the highest yield reported to date. It is found that in an acidic solution, gluconic acid is the major product while in a highly basic solution, selectivity to glucaric acid is poor due to its C-C bond cleavage to low carbon chain carboxylic acids. High temperatures and high Pt loadings result in lower selectivity to glucaric acid. Recyclability and characterization studies reveal that the catalyst is stable after five cycles with no sign of Pt leaching into the solution.
- Lee, Jechan,Saha, Basudeb,Vlachos, Dionisios G.
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p. 3815 - 3822
(2016/07/07)
-
- Method for producing glucaric acid
-
The present disclosure relates to a method for producing glucaric acid, and more particularly, to a method for producing glucaric acid including the steps of: (1) inputting aldohexose and potassium hydroxide to an aqueous solution; and (2) deriving a catalytic oxidation reaction after adding a supported noble metal catalyst to the aqueous solution under the presence of oxygen gas.
- -
-
Page/Page column 8: 10
(2016/02/03)
-
- Influence of the ionic liquid presence on the selective oxidation of glucose over molybdenum based catalysts
-
Two different approaches are proposed in this work in order to study the influence of the ionic liquid presence in the reaction of glucose oxidation by H2O2 in mild conditions. The ionic liquids are applied either as a solvent by using homogeneous Mo based catalyst, [Mo(O)(O2)2(H2O)n] complex, or by using it as an integral part of a heterogeneous catalyst, organic inorganic hybrids based on Mo Keggin structure. Both catalytic strategies resulted in acceptable glucose transformation degrees but lead to different oxidation products depending on the role of the ionic liquid. The hybrid approach restrains the number of the received products being the most selective one. A detailed study of the effect of the hybrid nature and reaction conditions is proposed in the second part of this study.
- Megías-Sayago,Carrasco,Ivanova,Montilla,Galindo,Odriozola
-
-
- Conformation analysis of d-glucaric acid in deuterium oxide by NMR based on its JHH and JCH coupling constants
-
d-Glucaric acid (GA) is an aldaric acid and consists of an asymmetric acyclic sugar backbone with a carboxyl group positioned at either end of its structure (i.e., the C1 and C6 positions). The purpose of this study was to conduct a conformation analysis of flexible GA as a solution in deuterium oxide by NMR spectroscopy, based on J-resolved conformation analysis using protonproton (3JHH) and protoncarbon (2JCH and 3JCH) coupling constants, as well as nuclear overhauser effect spectroscopy (NOESY). The 2JCH and 3JCH coupling constants were measured using the J-resolved heteronuclear multiple bond correlation (HMBC) NMR technique. NOESY correlation experiments indicated that H2 and H5 were in close proximity, despite the fact that these protons were separated by too large distance in the fully extended form of the chain structure to provide a NOESY correlation. The validities of the three possible conformers along the three different bonds (i.e., C2C3, C3C4, and C4C5) were evaluated sequentially based on the J-coupling values and the NOESY correlations. The results of these analyses suggested that there were three dominant conformers of GA, including conformer 1, which was H2H3:gauche, H3H4:anti, and H4H5:gauche; conformer 2, which was H2H3:gauche, H3H4:anti, and H4H5:anti; and conformer 3, which was H2H3:gauche, H3H4: gauche, and H4H5:anti. These results also suggested that all three of these conformers exist in equilibrium with each other. Lastly, the results of the current study suggested that the conformational structures of GA in solution were bent rather than being fully extended. Copyright
- Enomoto-Rogers, Yukiko,Iwata, Tadahisa,Masaki, Hisaharu,Ito, Tetsuya,Furihata, Kazuo
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p. 561 - 567
(2016/07/10)
-
- Ruthenium(III) catalyzed oxidation of sugar alcohols by dichloroisocyanuric acid - A kinetic study
-
Kinetics of ruthenium(III) catalyzed oxidation of biologically important sugar alcohols (myo-inositol, D-sorbitol, and D-mannitol) by dichloroisocyanuric acid was carried out in aqueous acetic acid - perchloric medium. The reactions were found to be first order in case of oxidant and ruthenium(III). Zero order was observed with the concentrations of sorbitol and mannitol whereas, a positive fractional order was found in the case of inositol concentration. An inverse fractional order was observed with perchloric acid in oxidation of three substrates. Arrhenius parameters were calculated and a plausible mechanism was proposed.
- Lakshman Kumar,Venkata Nadh,Radhakrishnamurti
-
p. 300 - 307
(2016/01/15)
-
- Oxidation of Glycerol to Dicarboxylic Acids Using Cobalt Catalysts
-
In this paper, the performance of cobalt-based catalysts was reported for oxidation of glycerol to dicarboxylic acids such as tartronic and oxalic acids. Cobalt catalysts supported on Mg3Al(OH)y(CO3)z structures prepared by a two-step modified sol-gel method showed 100% glycerol conversion with 64% and 24% selectivity toward tartronic and oxalic acids under mild conditions (55-70 °C and 0.1 MPa O2). Surface and bulk characterization by N2 adsorption/desorption, X-ray diffraction, and temperature-programmed reduction reveals that the cobalt sites interacting with surface hydroxides are catalytically more active than those incorporated into a framework leading to selective glycerol oxidation to dicarboxylic acids in one pot. On the basis of the experiments at different cobalt contents, temperatures, and concentration-time profiles, possible reaction pathways are discussed to explain the selectivity profile. Deactivation of the catalyst under certain conditions has been discussed as a result of loss of surface area due to structural changes.
- Jin, Xin,Zhao, Meng,Zeng, Chun,Yan, Wenjuan,Song, Ziwei,Thapa, Prem S.,Subramaniam, Bala,Chaudhari, Raghunath V.
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p. 4576 - 4583
(2016/07/12)
-
- Selective oxidation of uronic acids into aldaric acids over gold catalyst
-
Herein, uronic acids available from hemicelluloses and pectin were used as raw material for the synthesis of aldaric acids. Au/Al2O3 catalyst oxidized glucuronic and galacturonic acids quantitatively to the corresponding glucaric and galactaric acids at pH 8-10 and 40-60 °C with oxygen as oxidant. The pH has a significant effect on the initial reaction rate as well as desorption of acid from the catalyst surface. At pH 10, a TOF value close to 8000 h-1 was measured for glucuronic acid oxidation. The apparent activation energy Ea for glucuronic acid oxidation is dependent on the pH which can be attributed to the higher energy barrier for desorption of acids at lower pH. This journal is
- Rautiainen, Sari,Lehtinen, Petra,Chen, Jingjing,Vehkam?ki, Marko,Niemel?, Klaus,Leskel?, Markku,Repo, Timo
-
p. 19502 - 19507
(2015/04/28)
-
- OXIDATION PROCESS
-
A process utilizing nitric acid and oxygen as co-oxidants to oxidize aldehydes, alcohols, polyols, preferably carbohydrates, specifically reducing sugars to produce the corresponding carboxylic acids.
- -
-
Paragraph 0061
(2014/09/30)
-
- Modifications in the nitric acid oxidation of D-mannose: X-ray crystal structure of N,N0-dimethyl D-mannaramide
-
Nitric acid oxidation of D-mannose was carried out under an oxygen atmosphere using a computer controlled reactor. The process represents a catalytic oxidation of D-mannose with oxygen as the terminal oxidant. The crude oxidation product was esterified with methanolic HCl and the esterified product directly converted to crystalline N,N0-dimethyl-D-mannaramide with methylamine. Treatment of the diamide in aqueous sodium hydroxide gave solid disodium D-mannarate. The X-ray crystal structure of N,N0-dimethyl-D-mannaramide was determined as a model for the repeating D-mannaramide units of stereoregular poly(alkylene-D-mannaramides). Disodium D-mannarate was prepared as a precursor of esterified D-mannaric acid for use as a reactive diacid monomer to prepare poly-D-mannaramides.
- Carpenter, Chrissie A.,Hardcastle, Kenneth I.,Kiely, Donald E.
-
-
- Sonication-assisted low-temperature routes for the synthesis of supported Fe-TiO2 econanomaterials: Partial photooxidation of glucose and phenol aqueous degradation
-
Fe-doped TiO2-supported photocatalytic materials prepared by the use of a mild ultrasound-assisted protocol have been found to possess excellent selectivities in glucose oxidation and total phenol mineralization. These materials were characterized by a number of techniques such as XRD, diffuse reflectance UV/Vis spectroscopy, N2 physisorption, X-ray photoelectron spectroscopy, SEM with X-ray microanalysis, HRTEM, and flame atomic absorption spectroscopy. The proposed synthesis method was found to have a significant effect on textural properties, morphology, and visible-light responsiveness of nanophotocatalysts. The dopant agent was found to be in the form of Fe3+ ions. The effects of the textural properties, together with the Fe presence and the adsorption ability of the material (acidic properties), seem to be involved in the optimum photocatalytic activities found for Fe-TiO2 supported on zeolite. In phenol photodegradation, although Fe doping demonstrated the detrimental effect on the conversion rate, an improvement in the direct mineralization of phenol to CO2 and water, particularly for the SiO2-supported photocatalyst, with a negligible content of toxic byproducts in water has been observed in comparison with commercially available Evonik P25.
- Colmenares, Juan C.,Magdziarz, Agnieszka,Chernyayeva, Olga,Lisovytskiy, Dmytro,Kurzydlowski, Krzysztof,Grzonka, Justyna
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p. 2270 - 2277
(2013/08/23)
-
- Room temperature versatile conversion of biomass-derived compounds by means of supported TiO2 photocatalysts
-
The selective oxidation of glucose and degradation of phenol in liquid phase were studied in the presence of supported TiO2 photocatalysts. Photocatalysts were synthesized by a modified ultrasound-assisted sol-gel method. The fact of supporting TiO2 on zeolite type Y is giving more selective photocatalyst in glucose oxidation toward glucaric acid (GUA) and gluconic acid (GA) (total selectivity approx. 68%, after 10 min illumination time and 50%H2O/50%acetonitrile solvent composition) than the unsupported TiO2 and the commercially available photocatalyst Evonik P-25. Photocatalysts worked at room temperature, atmospheric pressure and very short reaction times (up to 15 min). Additionally, these photocatalysts were investigated in the mineralization of phenol as a cellulosic industries water contaminant. It was observed that fumed silica is a better option than zeolite as titania support in phenol aqueous degradation. Ultrasound-promoted sol-gel methodology is giving promising supported TiO2 photocatalysts for water purification and solar chemicals production.
- Colmenares, Juan C.,Magdziarz, Agnieszka
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p. 156 - 162
(2013/02/23)
-
- Modifications in the nitric acid oxidation of d-glucose
-
The nitric acid oxidation of d-glucose was reinvestigated in an effort to better understand and improve the oxidation and subsequent work up steps. The oxidation was carried out using a computer controlled reactor employing a closed reaction flask under an atmosphere of oxygen which allowed for a catalytic oxidation process with oxygen as the terminal oxidant. Removal of nitric acid from product included the use of both diffusion dialysis and nanofiltration methodologies. Product analysis protocols were developed using ion chromatography.
- Smith, Tyler N.,Hash, Kirk,Davey, Cara-Lee,Mills, Heidi,Williams, Holly,Kiely, Donald E.
-
experimental part
p. 6 - 13
(2012/03/12)
-
- Characterization of D-glucaric acid using NMR, X-ray crystal structure, and MM3 molecular modeling analyses
-
D-Glucaric acid was characterized in solution by comparing NMR spectra from the isotopically unlabeled molecule with those from d-glucaric acid labeled with deuterium or carbon-13 atoms. The NMR studies provided unequivocal assignments for all carbon atoms and non-hydroxyl protons of the molecule. The crystal structure of d-glucaric acid was obtained by X-ray diffraction techniques and the structure was a close match to the low energy conformation generated from a Monte-Carlo-based searching protocol employing the mm3 molecular mechanics program. The molecule adopts a bent structure in both the crystalline and computationally generated lowest-energy structure, a conformation that is devoid of destabilizing eclipsed 1,3-hydroxyl interactions.
- Denton, Travis T.,Hardcastle, Kenneth I.,Dowd, Michael K.,Kiely, Donald E.
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experimental part
p. 2551 - 2557
(2011/12/02)
-
- Improved preparative electrochemical oxidation of d-glucose to d-glucaric acid
-
The 2,2,6,6-tetramethyl-1-piperidinyloxy free radical (TEMPO) mediated electrochemical oxidation of d-glucose to d-glucaric acid on a synthetically useful scale is reported. Using TEMPO and a graphite felt anode combined with a stainless steel cathode, d-glucose was oxidized under different conditions (pH, temperature, co-oxidant), and the reaction outcomes were analyzed. Optimized conditions for such oxidation are provided along with few new interesting results unique to this reaction, such as the appearance of a novel triacid.
- Ibert, Mathias,Fuertès, Patrick,Merbouh, Nabyl,Fiol-Petit, Catherine,Feasson, Christian,Marsais, Francis
-
experimental part
p. 3589 - 3594
(2010/07/08)
-
- Genome-wide screening reveals the genetic determinants of an antibiotic insecticide in Bacillus thuringiensis
-
Thuringiensin is a thermostable secondary metabolite in Bacillus thuringiensis and has insecticidal activity against a wide range of insects. Until now, the regulatory mechanisms and genetic determinants involved in thuringiensin production have remained unclear. Here, we successfully used heterologous expression-guided screening in an Escherichia coli-Bacillus thuringiensis shuttle bacterial artificial chromosome library, to clone the intact thuringiensin synthesis (thu) cluster. Then the thu cluster was located on a 110-kb endogenous plasmid bearing insecticide crystal protein gene cry1Ba in strain CT-43. Furthermore, the plasmid, named pBMB0558, was indirectly cloned and sequenced. The gene functions on pBMB0558 were annotated by BLAST based on the GenBank and KEGG databases. The genes on pBMB0558 could be classified into three functional modules: a thuringiensin synthesis cluster, a type IV secretion system-like module, and mobile genetic elements. By HPLC coupling mass spectrometer, atmospheric pressure ionization with ion trap, and TOF technologies, biosynthetic intermediates of thuringiensin were detected. The thuE gene is proved to be responsible for the phosphorylation of thuringiensin at the last step by vivo and vitro activity assays. The thuringiensin biosynthesis pathway was deduced and clarified. We propose that thuringiensin is an adenine nucleoside oligosaccharide rather than an adenine nucleotide analog, as is traditionally believed, based on the predicted functions of the key enzymes, glycosyltransferase (ThuF) and exopolysaccharide polymerization protein (Thu1).
- Liu, Xiao-Yan,Ruan, Li-Fang,Hu, Zhen-Fei,Peng, Dong-Hai,Cao, Shi-Yun,Yu, Zi-Niu,Liu, Yao,Zheng, Jin-Shui,Sun, Ming
-
scheme or table
p. 39191 - 39200
(2011/10/09)
-
- Convenient large-scale synthesis of D-glucaro-1,4:6,3-dilactone
-
(Chemical Equation Presented) Calcium D-glucarate was converted into D-glucaro-1,4:6,3-dilactone on 32-g, 1-kg, and 22-kg scale, using azeotropic distillation with methyl isobutyl ketone to drive the dehydration. The crystalline product was g99.5% pure by
- Gehret, Troy C.,Frobese, A. Stephen,Zerbe, James S.,Chenault, H. Keith
-
scheme or table
p. 8373 - 8376
(2010/02/28)
-
- Myo-inositol oxygenases
-
The invention provides methods and materials related to the production of organic products such as glucuronic acid, ascorbic acid, and glucaric acid. Specifically, the invention provides cells, methods for culturing cells, isolated nucleic acid molecules, and methods and materials for producing various organic products such as glucuronic acid, ascorbic acid, and glucaric acid.
- -
-
-
- Development of a transient response technique for heterogeneous catalysis in the liquid phase, Part 1: Applying an electrospray ionization mass spectrometry (ESI-MS) detector
-
We have developed a novel, transient response technique for liquid-phase heterogeneous catalytic studies, equipped with an electrospray ionization mass spectrometry (ESI-MS) detector. The technique was successfully applied as an online method for real-time detection of species dissolved in aqueous product streams at the exit of a catalytic reactor. Two test reactions, nitrite reduction with Pt/SiO2 and glucose oxidation with Pt/CNF/Ni, were used to demonstrate semi-quantitative monitoring of reactants, intermediates, and products. The capability of the novel technique is demonstrated by the fact that the ESI-MS detector is sufficiently sensitive to determine quantitatively extreme small amounts of physisorbing nitrite, down to 0.5% of a monolayer on the Pt surface. Nitrite also reacts with preadsorbed hydrogen, and the quantitative experimental results agree with the formation of both nitrogen and ammonia. The ESI-MS detector is able to distinguish between different components simultaneously, as in the case of glucose oxidation; this is its most significant advantage over existing transient techniques. A limitation of ESI-MS is its inability to detect gases dissolved in liquids, due to the relatively mild ionization process through electrospray. The second part of this article discusses an alternative detector to satisfy this deficiency.
- Radivojevic,Ruitenbeek,Seshan,Lefferts
-
experimental part
p. 244 - 254
(2009/02/05)
-
- SYNTHESIS OF ALDONOLACTONES, ALDAROLACTONES, AND ALDARODILACTONES USING GAS SPARGING
-
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 13-14
(2008/06/13)
-
- Method for the separation of carbohydrate acids
-
Separating a carbohydrate carboxylic acid (I) from a mixture containing at least one other such acid (Ia) by single-step reactive extraction with an extractant (A) that comprises at least one alcohol (II) with more than 3C and at least one alkylamine (III), is new.
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-
Page/Page column 4-5
(2008/06/13)
-
- METHOD FOR SELECTIVE CARBOHYDRATE OXIDATION USING SUPPORTED GOLD CATALYSTS
-
The invention relates to a method for the selective oxidation of a carbohydrate in the presence of a gold catalyst comprising gold particles distributed in a nanodispersed manner on a metal oxide support, and to a method for the selective oxidation of an oligosaccharide in the presence of a gold catalyst comprising gold particles distributed in a nanodispersed manner on a carbon or metal oxide support. The invention also relates to aldonic acid oxidation products produced using said method.
- -
-
Page/Page column 40-42
(2010/02/09)
-
- 4-AcNH-Tempo-catalyzed oxidation of aldoses to aldaric acids using chlorine or bromine as terminal oxidants
-
The 4-AcNH-TEMPO-catalyzed oxidation of D-glucose to D-glucaric acid using elemental chlorine or bromine as the terminal oxidant is reported. The pH and temperature of the reactions were closely controlled to be between 0-5 deg C and pH 11.5, respectively. Spectroscopically (1H NMR) determined yields of glucarate were greater than 90 percent; yields of crystalline monopotassium D-glucarate (or disodium D-glucarate), isolated and purified by precipitation, were between 70 and 85 percent. Oxidations of mannose to mannaric acid and galactose to mucic acid were also demonstrated.
- Merbouh, Nabyl,Bobbitt, James M.,Brueckner, Christian
-
-
- Determination of the side-products formed during the nitroxide-mediated bleach oxidation of glucose to glucaric acid
-
The side products formed in the TEMPO-mediated oxidation of glucose to glucaric acid were determined by GC. Next to glucaric acid, gluconic acid, the intermediate in the oxidation, the degradation products, oxalic acid, tartronic acid, meso-(erythraric) a
- Ibert, Mathias,Marsais, Francis,Merbouh, Nabyl,Brückner, Christian
-
p. 1059 - 1063
(2007/10/03)
-
- Kinetic and mechanistic investigation of oxidation of uronic acids by sodium N-bromoarylsulfonamides in alkaline medium
-
The kinetics of oxidation of uronic acids (UAs), D-glucuronic acid and D-galacturonic acid, by sodium N-bromo-p-toluenesulfonamide or bromamine-T (BAT) and sodium N-bromobenzenesulfonamide or bromamine-B (BAB) in alkaline medium at 30°C have been investigated and the rate law, rate=k [OX] [UA] [HO-] where [OX][BAT] or [BAB] was observed. The product p-toluenesulfonamide (PTS) or benzenesulfonamide (BSA) and ionic strength have no influence on the rate. The rate decreased when the dielectric constant (ε) of the medium was decreased. The rate increased in D2O medium. Proton inventory studies were made in D2O-H2O mixtures. Effect of temperature was studied and from the Arrhenius plots, activation parameters were computed. A mechanism involving the formation of enediol anion, which reacts with positive bromine of the bromamine in the rate-limiting step is suggested.
- Shashikala,Rangappa
-
p. 491 - 499
(2007/10/03)
-
- Oxidation of D-glucose to D-gluconic and D-glucaric acids catalyzed by sodium nitrite
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Kinetics of catalytic oxidation of D-glucose in the HClO4-H2O-sulfolane system containing NaNO2 was studied. Kinetic equations of the process were derived. A scheme for oxidation of D-glucose with oxygen in the presence of NaNO2 was proposed.
- Grigor'eva,Chernaya,Trusov
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p. 2021 - 2026
(2007/10/03)
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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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- Nitric acid removal from oxidation products
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A method for synthesizing and isolating an oxidation product is disclosed wherein nitric acid is reacted with an oxidizable reactant and the desired oxidized product is extracted using an organic solvent such as a dialkyl ether. The method permits the direct crystallization of aldaric acids such as glucaric acid and mannaric acid and eliminates the necessity of employing complicated, time consuming and wasteful neutralization/acidification steps.
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- The reaction of hyaluronic acid and its monomers, glucuronic acid and N- acetylglucosamine, with reactive oxygen species
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Synovial fluid is a ~0.15% (w/v) aqueous solution of hyaluronic acid (HA), a polysaccharide consisting of alternating units of GlcA and GlcNAc. In synovial fluid of patients suffering from rheumatoid arthritis, HA is thought to be degraded either by radicals generated by Fenton chemistry (Fe2+/H2O2) or by NaOCl generated by myeloperoxidase. We investigated the course of model reactions of these two reactants in physiological buffer with HA, and with the corresponding monomers GlcA and GlcNAc. meso-Tartaric acid, arabinuronic acid, arabinaric acid and glucaric acid were identified by GC-MS as oxidation products of glucuronic acid. When GlcNAc was oxidised, erythronic acid, arabinonic acid, 2-acetamido-2-deoxy-gluconic acid, glyceric acid, erythrose and arabinose were formed. NaOCl oxidation of HA yielded meso-tartaric acid; in addition, arabinaric acid and glucaric acid were obtained by oxidation with Fe2+/H2O2. These results indicate that oxidative degradation of HA proceeds primarily at glucuronic acid residues. meso-Tartaric acid may be a useful biomarker of hyaluronate oxidation since it is produced by both NaOCl and Fenton chemistry.
- Jahn, Michael,Baynes, John W.,Spiteller, Gerhard
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p. 228 - 234
(2007/10/03)
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- Kinetics and mechanism of the oxidation of ethyl glycol, D-mannitol and D-sorbitol by hexacyanoferrate(III) ion in aqueous alkaline medium
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The rate of oxidation of ethyl glycol, D-mannitoI and D-sorbitol by hexacyanoferrate(III) ion in aqueous alkaline medium is directly proportional to the organic substrate and hydroxide ion concentrations. The dependence of rate on hexa-cyanoferrate(III) ion is nearly first order at lower concentrations and tends towards zero order at higher concentrations. A probable reaction mechanism has been suggested.
- Singh,Verma,Gupta, Arti,Mittal, Anjali
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p. 392 - 394
(2007/10/03)
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- Kinetics and mechanism of the oxidation of uronic acdis by sodium N-chlorobenzenesulphonamide in alkaline medium
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The kinetics of oxidation of D-glucuronic acid and D-galacturonic acid (UA) by sodium N-chlorobenzenesulphonamide or chloramine-B (CAB) in alkaline medium at 35°C has been investigated and the rate law, rate = k [CAB][UA][HO-] was observed. The product, benzenesulphonamide had no influence. Increase of ionic strength increased the rate and when the dielectric constant of the medium was decreased, the rate was decreased. The rate increased in D2O medium and the inverse solvent isotope effect k (D2O)/k (H2O) was 2.00. Proton inventory was studied for the reactions in H2O-D2O mixtures. Activation parameters have been determined from the Arrhenius plots. The mechanism assumes the formation of an enediol anion followed by its oxidation by the positive halogen in a rate limiting step.
- Rangappa,Raghavendra,Mahadevappa
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p. 359 - 371
(2007/10/03)
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- Oxidation of methyl and n-octyl α-D-glucopyranoside over graphite-supported platinum catalysts: Effect of the alkyl substituent on activity and selectivity
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The oxidation of methyl and n-octyl α-D-glucopyranoside to methyl and n-octyl α-D-glucopyranosiduronate with molecular oxygen over a graphite-supported platinum catalyst was investigated. An increase of the length of the n-alkyl substituent from methyl to n-octyl resulted in a ten-fold decrease of the catalyst activity and an increase of the selectivity at pH 8.0 and 323 K. The selectivity decreased with increasing pH. The lower activity for a longer n-alkyl substituent is attributed to steric effects upon adsorption on the platinum surface and not to internal diffusion limitations. A tentative reaction scheme is presented, which describes the formation of side products through oxidation of secondary hydroxyl groups, ring cleavage and hydrolysis. Major side products are mono- and di-carboxylates with 2, 4, and 6 carbon atoms and mono-carboxylates, resulting from the oxidation of the alkyl substituent. C-C-Bond cleavage mainly occurs between C-2 and C-3 or C-4 and C-5, the former being less important for a longer alkyl substituent. The higher selectivity for a longer alkyl substituent is attributed to its protecting ability against hydrolysis and the exposition of neighboring hydroxyl groups to the platinum surface.
- Vleeming, Johannes H.,Kuster, Ben F.M.,Marin, Guy B.
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p. 175 - 183
(2007/10/03)
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- Oxidation of uronic acids by sodium N-chloro-p-toluenesulphonamide in alkaline medium : A kinetic study
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Kinetics of oxidation of D-glucuronic acid and D-galacturonic acid (S) by sodium N-chioro-p-toluenesulphonamide or chloramine-T (CAT) in the presence of alkali at 35° has been investigated and the rate=k [CAT][S][HO-]. The product, p-toluenesulphonamide has no influence. Increase in ionic strength increases the rate and the rate decreases when the dielectric constant of the medium is decreased; The rate increases in D2O medium. Activation parameters have been determined from the Arrhenius plots. The mechanism involves the formation of an enediol anion followed by its oxidation by the positive halogen in a rate limiting step.
- Raghavendra,Mahadevappa,Rangappa
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p. 1079 - 1083
(2007/10/03)
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- Synthesis of stereoregular head,tail hydroxylated nylons derived from D-glucose
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A simple procedure for the preparation of stereoregular polyhydroxypolyamides, i.e., head,tail hydroxylated nylons, derived from D-glucaric acid and alkylenediamines is described. Sodium D-glucarate 6,3-lactone was made in two steps from monopotassium D-glucarate by way of D-glucaro-6,3-lactone. Methanol insoluble salt of sodium 6-[N-(aminoalkyl)]-D-glucaramide monomer precursors were conveniently prepared by refluxing methanol solutions of even-numbered C2 to C12 aliphatic diamines with insoluble sodium D-glucarate-6,3-lactone. Each of the resulting salts was esterified/lactonized at the C-1 carboxylate terminus with HCl/methanol, and the products were made basic to give the corresponding free base amino acid ester/lactone mixture. The latter spontaneously underwent self-polymerization to give the target polyamides. An important feature of this general procedure for stereoregular polyamides from chiral D-glucaric acid is that it does not require any carbohydrate hydroxyl group protection/deprotection steps.
- Chen, Liang,Kiely, Donald E.
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p. 5847 - 5851
(2007/10/03)
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- BIOSYNTHESIS OF D-GLUCARIC ACID IN MAMMALS: A FREE-RADICAL MECHANISM?
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In the presence of iron salts and hydrogen peroxide, D-glucuronic acid was converted into D-glucaric acid.The reaction was strongly inhibited by free-radical scavengers and is ascribed to the action of the hydroxyl radical.The formation of D-glucarate was dependent upon pH and occurred in the presence of some iron-complexing agents.The first product of oxidation was a lactone that was a strong inhibitor of β-D-glucuronidase and assumed to be D-glucaro-1,5-lactone.Microsomal preparations in the presence of NADPH also produced D-glucarate from D-glucuronic acid, presumably due to formation of hydrogen peroxide, and the product was an inhibitor of β-D-glucuronidase.Superoxide did not produce D-glucarate from D-glucuronate.The cytochrome P450 system is more likely than "glucuronolactone dehydrogenase" to be responsible for the production of D-glucaric acid in vivo.
- Marsh, Charles A.
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p. 119 - 131
(2007/10/02)
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- THE SELECTIVE OXIDATION OF ALDOSES AND ALDONIC ACIDS TO 2-KETOALDONIC ACIDS WITH LEAD-MODIFIED PLATINUM-ON-CARBON CATALYSTS
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Aldoses and aldonic acids have been oxidised with oxygen and air at 55 deg in water, using Pt/C catalysts.After oxidation of the reducing group, if available, the primary hydroxyl group is preferentially oxidised using an unmodified catalyst.Addition of a lead(II) salt changes the preference dramatically towards oxidation at the position α to the carboxyl group.Provided that oxygen transfer to the liquid phase is carefully controlled in order to prevent deactivation of the catalyst, 2-ketoaldonic acids can be prepared in high yields.
- Smits, Pierre C. C.,Kuster, Ben F. M.,Wiele, Kees van der,Baan, Hessel S. van der
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p. 227 - 236
(2007/10/02)
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- Glycosides of N-Hydroxy-N-arylamine Derivatives. Part 3. Kinetic and Mechanistic Studies on the Degradation Reaction of O-Glycosides of N-Hydroxy-N-arylamines and their Acetohydroxamic Acids in Acidic and Alkaline Media
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Good first-order kinetics of the degradation reaction of 1--1-deoxy-β-D-glucopyranoses (1a-d), 1-(N-arylamino)oxy-1-deoxy-β-D-glucopyranose (2a) and sodium 1--1-deoxy-β-D-glucopyranuronate (3a) in aqueous acidic solutions have been observed.Compounds (1a-d) and (3a) were fairly stable in neutral solution, but in aqueous acidic solutions at 20 deg C these compounds decomposed to the corresponding arylamino derivatives (4a-d) and D-gluconic acid (5) .The compound (2a) decomposed ca. 7400 times faster than compound (1a) to the same products (4a) and (5) in the same conditions.In an alkaline solution, compounds (1a)-(3a) gave the corresponding azoxybenzene.In the acid-catalysed redox degradation reaction, the hydrolysis of the N-acetyl group of compounds (1a-d) and (3a) is considered to be the rate-determining step.The effects of pH and additives on the reaction rate are reported.The mechanism of the acid-catalysed redox fission of the N-O linkage in the above O-glycosides is discussed.
- Yoshioka, Tadao,Uematsu, Takayoshi
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p. 1377 - 1382
(2007/10/02)
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