- Hybrid Organic–Inorganic Anatase as a Bifunctional Catalyst for Enhanced Production of 5-Hydroxymethylfurfural from Glucose in Water
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Hybrid organic–inorganic anatase (hybrid-TiO2) is prepared by a facile hydrothermal synthesis method employing citric acid. The synthetic approach results in a high surface-area nanocrystalline anatase polymorph of TiO2. The uncalcin
- Lanziano, Carlos A. S.,Moya, Silvia F.,Barrett, Dean. H.,Teixeira-Neto, Erico,Guirardello, Reginaldo,de Souto da Silva, Felipe,Rinaldi, Roberto,Rodella, Cristiane B.
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- Analysis of the hydrolysis of inulin using real time 1H NMR spectroscopy
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The hydrolysis of various carbohydrates was investigated under acidic conditions in real time by 1H NMR spectroscopy, with a focus on the polysaccharide inulin. Sucrose was used as a model compound to illustrate the applicability of this technique. The hydrolysis of sucrose was shown to follow pseudo first order kinetics and have an activation energy of 107.0 kJ mol -1 (SD 1.7 kJ mol-1). Inulin, pullulan and glycogen also all followed pseudo first order kinetics, but had an initiation phase at least partially generated by the protonation of the glycosidic bonds. It was also demonstrated that polysaccharide chain length has an effect on the hydrolysis of inulin. For short chain inulin (DPn 18, SD 0.70) the activation energy calculated for the hydrolytic cleavage of glucose was similar to sucrose at 108.5 kJ mol-1 (SD 0.60). For long chain inulin (DPn 30, SD 1.3) the activation energy for the hydrolytic cleavage of glucose was reduced to 80.5 kJ mol-1 (SD 2.3 kJ mol-1). This anomaly has been attributed to varied conformations for the two different lengths of inulin chain in solution.
- Barclay, Thomas,Ginic-Markovic, Milena,Johnston, Martin R.,Cooper, Peter D.,Petrovsky, Nikolai
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- Direct conversion of inulin to 5-hydroxymethylfurfural in biorenewable ionic liquids
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In this work, we found that inulin is soluble in ionic liquids (ILs) choline chloride (ChoCl)/oxalic acid and ChoCl/citric acid, which are prepared entirely from cheap and renewable materials. On the basis of this discovery, we conducted the one pot react
- Hu, Suqin,Zhang, Zhaofu,Zhou, Yinxi,Song, Jinliang,Fan, Honglei,Han, Buxing
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- Exceptionally Efficient and Recyclable Heterogeneous Metal–Organic Framework Catalyst for Glucose Isomerization in Water
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Heterogeneous catalysts are desired for the conversion of glucose, the most abundant sugar in renewable biomass, but presently their synthesis requires highly toxic chemicals with long synthesis times. We report the conversion of glucose into fructose and 5-hydroxymethylfurfural on a heterogeneous catalyst that is stable and selective and operates in the most environmentally benign solvent, water. We used a bifunctional solid with Lewis and Br?nsted acid sites by partially replacing the organic linker of the zirconium organic framework UiO-66 with 2-monosulfo-benzene-1,4-dicarboxylate. This catalyst showed high product selectivity (90 %) to 5-hydroxymethylfurfural and fructose at 140 °C in water after a reaction time of 3 h. It was recyclable and showed only a minor loss in activity after the third recycle, offering a realistic solution for the bottleneck glucose isomerization reaction for scale-up and industrial application of biomass utilization.
- Oozeerally, Ryan,Burnett, David L.,Chamberlain, Thomas W.,Walton, Richard I.,Degirmenci, Volkan
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- Cs-substituted tungstophosphate-supported ruthenium nanoparticles as efficient and robust bifunctional catalysts for the conversion of inulin and cellulose into hexitols in water in the presence of H2
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Cellulose and inulin, two important biomasses, can be transformed to polyols using bifunctional catalysts combining acid sites for hydrolysis and metal nanoparticles for hydrogenation. Here, we report that Ru nanoparticles loaded on a Keggin-type polyoxometalate, i.e., Cs3PW12O40, without intrinsic Bronsted acidity exhibit superior catalytic performances for the transformation of inulin and cellulose into hexitols in water in the presence of H2. We demonstrated that new Bronsted acid sites were generated from H2 on the Ru/Cs3PW12O40 catalyst. The H2-originated reversible Bronsted acid sites were robust during the transformation of biomass under hydrothermal conditions. We further found that the mean size of Ru nanoparticles determined the product selectivity in the conversion of inulin under H2. The catalyst with larger Ru nanoparticles favoured the formation of fructose, the hydrolysis product, while the major products were hexitols over the catalyst with a smaller Ru particle size. We clarified that, as compared to that of inulin hydrolysis, the rate of fructose hydrogenation increased more rapidly upon decreasing the Ru particle size.
- Deng, Weiping,Zhu, Enze,Liu, Mi,Zhang, Qinghong,Wang, Ye
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- OSDA-Free Zeolite Beta with High Aluminum Content Efficiently Catalyzes a Tandem Reaction for Conversion of Glucose to 5-Hydroxymethylfurfural
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Organic structure-directing agent (OSDA)-free zeolite Beta with high Al content exhibit remarkably high catalytic performance in the conversion of glucose to 5-hydroxymethylfurfural (HMF) by virtue of their appropriate acid properties; specifically, a sufficient number of Lewis acid sites were generated by calcination of the NH4-form zeolite, while the original Bronsted acid sites were substantially maintained, with both acid sites being in close proximity. The OSDA-free Beta catalyst, having a large number of Bronsted acid sites and sufficient Lewis acid sites, showed superior catalytic performance to a physical mixture of each type of acid catalyst with a similar number of each acid site. This behavior could be ascribed to the high reactivity and slow intrazeolitic diffusion of fructose. The structure of the Al species active in the isomerization of glucose to fructose is discussed based on relationships between catalytic activities and changes in Al species by the calcination, changes that were observed by 27Al magic-angle spinning (MAS) NMR and IR spectroscopies. Lewis and Bronsted, working together: Organic structure-directing agent (OSDA)-free zeolite Beta with high Al content effectively promotes conversion of glucose to 5-hydroxymethylfurfural (HMF). The high aluminum content of the zeolite provides suitable acid properties; specifically, a large number of Bronsted acid sites with a sufficient number of Lewis acid sites in close proximity. The zeolite calcined at 773 K showed >70 % yield of HMF.
- Otomo, Ryoichi,Yokoi, Toshiyuki,Tatsumi, Takashi
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- Effect of CO2 on conversion of inulin to 5-hydroxymethylfurfural and propylene oxide to 1,2-propanediol in water
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The CO2-water system has the potential to serve as a substitute for mineral acids for some reactions in acidic media. In this work, two reactions under hydrothermal conditions with and without CO2 were studied - the conversion of inulin to 5-hydroxymethylfurfural (5-HMF), and the hydrolysis of propylene oxide to 1,2-propanediol (1,2-PDO). The effects of CO2 pressure, reaction temperature and reactant concentration on the yield of 5-HMF and 1,2-PDO were examined. It was demonstrated that CO 2 could increase the yields of 5-HMF and 1,2-PDO considerably under optimized conditions. The methods to prepare 5-HMF and 1,2-PDO are greener, in that conventional acids are not required and the solution is neutralized automatically after depressurization. The Royal Society of Chemistry 2010.
- Wu, Suxiang,Fan, Honglei,Xie, Ye,Cheng, Yan,Wang, Qian,Zhang, Zhaofu,Han, Buxing
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- Glucosylation of acetic acid by sucrose phosphorylase
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Transglucosylation from sucrose to acetic acid by sucrose phosphorylase (EC 2.4.1.7) was studied. 1-O-Acetyl-α-D-glucopyranose was isolated as the main product of the enzyme reaction. We also compared the pH-dependence of transglycosylation catalyzed by sucrose phosphorylase toward carboxyl and hydroxyl groups. With hydroquinone as an acceptor molecule, the transfer ratio of glucose residue was higher at neutral pH. This pH-activity profile was similar to that of the phosphorolysis of sucrose by sucrose phosphorylase, but with acetic acid as an acceptor molecule, the transfer ratio of glucose residue was higher at low pH. These findings suggest that the undissociated carboxyl group is essential to the acceptor molecule for the transglycosylation reaction of sucrose phosphorylase. In a sensory test, the sour taste of acetic acid was markedly reduced by glucosylation. The threshold value of the sour taste of acetic acid glucosides was approximately 100 times greater than that of acetic acid.
- Nomura, Koji,Sugimoto, Kazuhisa,Nishiura, Hiromi,Ohdan, Kohji,Nishimura, Takahisa,Hayashi, Hideo,Kuriki, Takashi
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- NMR for direct determination of Km and Vmax of enzyme reactions based on the Lambert W function-analysis of progress curves
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1H NMR spectroscopy was used to follow the cleavage of sucrose by invertase. The parameters of the enzyme's kinetics, Km and V max, were directly determined from progress curves at only one concentration of the substrate. For comparison with the classical Michaelis-Menten analysis, the reaction progress was also monitored at various initial concentrations of 3.5 to 41.8 mM. Using the Lambert W function the parameters Km and Vmax were fitted to obtain the experimental progress curve and resulted in Km = 28 mM and V max = 13 μM/s. The result is almost identical to an initial rate analysis that, however, costs much more time and experimental effort. The effect of product inhibition was also investigated. Furthermore, we analyzed a much more complex reaction, the conversion of farnesyl diphosphate into (+)-germacrene D by the enzyme germacrene D synthase, yielding Km = 379 μM and kcat = 0.04 s- 1. The reaction involves an amphiphilic substrate forming micelles and a water insoluble product; using proper controls, the conversion can well be analyzed by the progress curve approach using the Lambert W function.
- Exnowitz, Franziska,Meyer, Bernd,Hackl, Thomas
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- Bifunctional heterogeneous catalysts derived from the coordination of adenosine monophosphate to Sn(iv) for effective conversion of sucrose to 5-hydroxymethylfurfural
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Adenosine 5′-monophosphate (AMP) with multiple functional groups can bind to various metal ions. In this work, AMP has been used as a ligand to coordinate Sn(iv) for the synthesis of porous coordination polymers (Sn-AMPs). The Sn-AMPs have both Br?nsted acid (BA) and Lewis acid (LA) sites and have been used as bifunctional heterogeneous catalysts for catalyzing the conversion of sucrose to 5-hydroxymethylfurfural (HMF), involving hydrolysis of sucrose to glucose and fructose, isomerization of glucose to fructose, and dehydration of fructose to HMF. The protonated N1 and OH–P of the coordinated AMP can form hydrogen bonds with glucose and fructose. This can promote the conversion of the sugars. Sn-AMP has exhibited a superior capability for the conversion of biomass-derived sugars into HMF. The HMF yields of 76.1%, 67.5% and 62.9% were achieved from fructose, glucose, and sucrose, respectively.
- Ji, Peijun,Jiao, Lutong,Meng, Han,Wang, Chenyu
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p. 630 - 640
(2022/02/09)
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- Two-step biosynthesis of D-allulose via a multienzyme cascade for the bioconversion of fruit juices
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D-Allulose, a low-calorie rare sugar with potential as sucrose substitute for diabetics, can be produced using D-allulose 3-epimerase (DAE). Here, we characterized a putative thermostable DAE from Pirellula sp. SH-Sr6A (PsDAE), with a half-life of 6 h at 60 °C. Bioconversion of 500 g/L D-fructose using immobilized PsDAE on epoxy support yielded 152.7 g/L D-allulose, which maintained 80% of the initial activity after 11 reuse cycles. A multienzyme cascade system was developed to convert sucrose to D-allulose comprising sucrose invertase, D-glucose isomerase and PsDAE. Fruit juices were treated using this system to convert the high-calorie sugars, such as sucrose, D-glucose, and D-fructose, into D-allulose. The content of D-allulose among total monosaccharides in the treated fruit juice remained between 16 and 19% during 15 reaction cycles. This study provides an efficient strategy for the development of functional fruit juices containing D-allulose for diabetics and other special consumer categories.
- Li, Chao,Li, Lei,Feng, Zhiyuan,Guan, Lijun,Lu, Fuping,Qin, Hui-Min
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- Linking Molecular Behavior to Macroscopic Properties in Ideal Dynamic Covalent Networks
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Dynamic covalent networks (DCvNs) are increasingly used in advanced materials design with applications ranging from recyclable thermosets to self-healing hydrogels. However, the relationship between the underlying chemistry at the junctions of DCvNs and their macroscopic properties is still not fully understood. In this work, we constructed a robust framework to predict how complex network behavior in DCvNs emerges from the chemical landscape of the dynamic chemistry at the junction. Ideal dynamic covalent boronic ester-based hydrogels were used as model DCvNs. We developed physical models that describe how viscoelastic properties, as measured by shear rheometry, are linked to the molecular behavior of the dynamic junction, quantified via fluorescence and NMR spectroscopy and DFT calculations. Additionally, shear rheometry was combined with Transition State Theory to quantify the kinetics and thermodynamics of network rearrangements, enabling a mechanistic understanding including preferred reaction pathways for dynamic covalent chemistries. We applied this approach to corroborate the "loose-bolt"postulate for the reaction mechanism in Wulff-type boronic acids. These findings, grounded in molecular principles, advance our understanding and rational design of dynamic polymer networks, improving our ability to predict, design, and leverage their unique properties for future applications.
- Marco-Dufort, Bruno,Iten, Ramon,Tibbitt, Mark W.
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supporting information
p. 15371 - 15385
(2020/10/20)
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- Erratum: Linking molecular behavior to macroscopic properties in ideal dynamic covalent networks (Journal of the American Chemical Society (2020) 142: 36 (15371-15385) DOI: 10.1021/jacs.0c06192)
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The "concentration of functional groups, c,"was defined incorrectly on page S18 of the Supporting Information. The (Table Presented) correct definition is as follows: c is the concentration of functional groups of one of the two network components, assuming that both components are present in equal amounts. Therefore, in a network formed from tetrafunctional macromers (f = 4) and where the total molar concentration of macromers is [PEG], c = f [PEG]/2 = 4[PEG]/2 = 2[PEG]. In the original Supporting Information, we took c as the total concentration of functional groups in the network, resulting in c = 4[PEG]. This formula was incorrect and resulted in erroneous values for select Keq or Gp data reported in Table 1 (page 15374) and Figure 8 (page 15381). The corrected Table 1 and Figure 8 are shown below, and the SI has been corrected accordingly. In addition, some of these data that are quoted in the article should be changed as follows (with the corrected values highlighted in bold). On page 15374: "Keq,c = 37.5 when c = 0.02 M,""Keq was determined to be 540 ± 65. [?] corresponding to Gp = 10.9 ± 2.0 kPa,"and "Keq was quantified as 277 ± 37 from NMR and 323 from DFT, corresponding to Gp = 8.0 ± 0.8 and 9.0 kPa, respectively."On page 15381: "The rheometric data exhibited a similar increase in Keq from 75 at pH 6 to 10750 at pH 9 (Figure 8c)"and "At pH 9, Keq = 1126 ± 108 and 565 (from spectroscopy and rheology, respectively) and then decreased sharply at pH 10 to Keq = 112 and 120 (Figure 8e,f)."On page 15373 (in the Figure 2 caption): "Keq = 540 ± 65."'Table Presented' These corrections do not affect any of the conclusions of the article but only the exact value of select parameters. We apologize for these errors and for any inconvenience caused to the readers. ? Associated Content: ? Supporting Information The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/jacs.0c10406. Synthesis, sample preparation, computational and experimental methods, and model descriptions (PDF). (Figure Presented).
- Iten, Ramon,Marco-Dufort, Bruno,Tibbitt, Mark W.
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supporting information
p. 18730 - 18731
(2020/11/19)
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- Tunable acidity in mesoporous carbons for hydrolysis reactions
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A mesoporous carbon (CMC) has been treated under acidic conditions (32.5 wt% HNO3 at 10 °C or 40 °C) to prepare two new carbon samples (HCMC10 and HCMC40), which developed higher acidity in terms of quantity of sites and surface acid strength. The properties of the three carbons have been studied by using various techniques (N2 adsorption/desorption, TEM, XRPD, Raman spectroscopy, 13C NMR, 2D 1H-13C NMR, and XPS). Aromatic -COOH and -OH groups were identified as the main surface acid sites. Acid site density has been determined by pulse liquid-solid phase adsorption experiments carried out in different liquids. The samples retained acidity features in water, due to hydrophobicity of the surfaces, while acidity dropped when measured in methanol. From NH3-TPD analysis, a ranking of acid strength could be obtained: HCMC40 > HCMC10 > CMC. The good acidity of the carbon samples allowed them to act as catalysts in the hydrolysis reaction of sucrose to glucose and fructose. The catalytic activity of the carbon samples was compared to that of Amberlite, a commercial sulfated acid resin; the observed kinetic constant of HCMC40 was similar to that of Amberlite.
- Ferri,Campisi,Carniti,Gervasini,Shen
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supporting information
p. 5873 - 5883
(2020/04/29)
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- Hydrogenation of crude and purified d-glucosone generated by enzymatic oxidation of d-glucose
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D-Fructose is an important starting material for producing furfurals and other industrially important chemicals. While the base-catalyzed and enzymatic conversion of d-glucose to d-fructose is well known, the employed methods typically provide limited conversion. d-Glucosone can be obtained from d-glucose by enzymatic oxidation at the C2 position and, subsequently, selectively hydrogenated at C1 to form d-fructose. This work describes an investigation on the hydrogenation of d-glucosone, using both chromatographically purified and crude material obtained directly from the enzymatic oxidation, subjected to filtration and lyophilization only. High selectivities towards d-fructose were observed for both starting materials over a Ru/C catalyst. Hydrogenation of the crude d-glucosone was, however, inhibited by the impurities resulting from the enzymatic oxidation process. Catalyst deactivation was observed in the case of both starting materials.
- Aho, Atte,Lassfolk, Robert,Leino, Reko,Murzin, Dmitry Yu.
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p. 30476 - 30480
(2020/09/11)
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- Selective two-step synthesis of 2,5-diformylfuran from monosaccharide, disaccharide, and polysaccharide using H-Beta and octahedral MnO2 molecular sieves
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This study deals with an economical, efficient, and sustainable catalytic process with excellent EcoScore and E-factor values for the selective, two-step synthesis of 2,5-diformylfuran (with a yield higher than 90%) from carbohydrates, especially disaccharide and polysaccharide. This catalytic process involves the abundant and low cost carbohydrate as reactant and economical and sustainable catalysts, H-Beta and octahedral MnO2 molecular sieve. In this two step approach, H-Beta is used in the first step for the conversion of carbohydrate to 5-hydroxymethylfurfural (HMF). Br?nsted acidity of H-Beta catalyzes the hydrolysis and dehydration reactions whereas Lewis acidity catalyzes the isomerization to produce HMF. Thus, H-Beta is suitable for the conversion of various carbohydrate molecules (starch, sucrose, glucose and fructose) to HMF. After the first step, H-Beta is withdrawn and then the reaction mixture is subjected to oxidation catalyst, octahedral MnO2 molecular sieve, in the presence of O2 atmosphere to achieve the high 2,5-diformylfuran (DFF) yield. Molecular oxygen (1 atmosphere, O2 filled balloon) is used as an eco-friendly and economical oxidant. Furthermore, no over oxidation product of DFF is observed. HMF and DFF are recovered from the reaction mixture by the extraction with methyl isobutyl ketone (MIBK) using water and brine solutions. DFF yields of 97.1%, 95.3%, 93.4% and 91.5% are obtained when the reactions are carried out using fructose, sucrose, glucose, and starch, respectively. Stepwise addition of catalysts improves DFF yield (>90%) from fructose, glucose, sucrose, and especially starch. Moreover, the H-Beta and octahedral MnO2 molecular sieve are easily separable and recyclable.
- Sarmah, Bhaskar,Srivastava, Rajendra
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- One-pot sol-gel synthesis of a phosphated TiO2 catalyst for conversion of monosaccharide, disaccharides, and polysaccharides to 5-hydroxymethylfurfural
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Catalytic conversion of biomass or biomass-derived carbohydrates into 5-hydroxymethylfurfural (HMF) is an important reaction for the synthesis of bio-based polymers, fuels, and other industrially useful products. In this study, phosphated titania (P-TiO2) catalysts with different phosphoric acid content were prepared through a simple one-pot sol-gel method and characterized by BET, XRD, FT-IR, NH3-TPD, py-FT-IR, and XPS techniques. The catalyst characterization results revealed the incorporation of phosphorus into the TiO2 framework in the form of a Ti-O-P bond. The P-TiO2 catalysts were applied to the conversion of glucose (≥10 wt%) into HMF in a biphasic water/THF reaction medium at 175 °C. Under optimized reaction conditions, 98% glucose conversion and 53% HMF yield were obtained over a 15P-TiO2 catalyst, and the catalyst was reused for several cycles with consistent activity and selectivity. The presence of both Br?nsted and Lewis acid sites, high BET surface area and pore volume, and high acidity could account for the high catalytic activity and selectivity. Besides, the 15P-TiO2 catalyst was also demonstrated to be active for the conversion of disaccharides (sucrose and cellobiose), polysaccharides (starch and microcrystalline cellulose) and industrial grade sugar syrups into HMF with reasonable yield.
- Rao, Kasanneni Tirumala Venkateswara,Souzanchi, Sadra,Yuan, Zhongshun,Xu, Chunbao
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supporting information
p. 12483 - 12493
(2019/08/12)
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- Tin Grafted on Modified Alumina-Catalyzed Isomerisation of Glucose to Fructose
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The present study focuses on designing a catalyst based on hot water treated alumina (Al2O3-HWT) for the conversion of glucose to fructose. The glucose isomerisation reactions are performed with tin incorporated on parent Al2O3 and Al2O3-HWT in methanol. 0.5 wt% Sn/Al2O3-HWT affords a combined yield of fructose and methylfructoside (30.4%) which is two-fold higher than that obtained with 0.5wt% Sn/Al2O3 (15.1%), implying the importance of hot water treatment of Al2O3. Al2O3-HWT shows a very broad peak centred around 3440 cm-1, which could be assigned to OH stretching band of gibbsite, γ-Al(OH)3 which significantly diminished after solid state ion-exchange with SnCl4.5H2O (0.5 wt% Sn/Al2O3-HWT). UV-Vis diffused reflectance spectrum of 0.5 wt% Sn/Al2O3-HWT displays a peak centered at 241 nm, which can be ascribed to the incorporation of tin into the alumina network. XRD patterns of 0.5, 3 and 5 wt% Sn/Al2O3-HWT show that no peak corresponding to SnO2 is formed. Importantly, 0.5wt% SnO2/Al2O3-HWT exhibits a low activity, giving 13.2% of the total yield of fructose and methylfructoside, respectively, compared to 0.5wt% Sn/Al2O3-HWT (30.4% fructose), signifying the role of incorporated tin into the alumina network.
- Yatoo, Muhamad Aadil,Saravanamurugan, Shunmugavel
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- FeVO4 decorated –SO3H functionalized polyaniline for direct conversion of sucrose to 2,5-diformylfuran & 5-ethoxymethylfurfural and selective oxidation reaction
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In this study, a multi-functional catalyst, FeVO4 supported –SO3H functionalized polyaniline is prepared. First FeVO4 supported polyaniline is prepared. Then the resultant material is sulfonated using chlorosulphonic acid to obtain FeVO4 supported –SO3H functionalized polyaniline. This multi-functional catalyst exhibits excellent activity in the synthesis of 5-hydroxymethylfurfural from sucrose and oxidation of a wide range of aromatic and aliphatic alcohols. Further, the catalyst exhibits very good activity in the one-pot direct conversion of sucrose/fructose to 2,5-diformylfuran (DFF) and 5-ethoxymethylfurfural (EMF). This catalytic process involves the economical sucrose as a reactant and economical multi-functional catalyst based on polyaniline. In this one-pot, two-step process, -SO3H functionalized polyaniline is used in the first step for the conversion of sucrose to 5-hydroxymethylfurfural (HMF) followed by selective oxidation of HMF to DFF using FeVO4 sites present in the multi-functional catalyst. Moreover, acidic sites present in the multi-functional catalyst are suitable for the conversion of sucrose/fructose/HMF to EMF. Furthermore, molecular oxygen (1 atmosphere, 10 ml/min) is used as an eco-friendly and economical oxidant for the selective oxidation of a wide range of aromatic and aliphatic alcohols to aldehydes. The multi-functional catalyst presented here has been easily separated and recycled that make the process sustainable and economical for commercial perspectives.
- Kumar, Abhinav,Srivastava, Rajendra
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- Effect of Tetrahydrofuran on the Solubilization and Depolymerization of Cellulose in a Biphasic System
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The dissolution of cellulose from biomass is a crucial but complicated issue for maximizing the utilization of biomass resources to produce valuable chemicals, because of the extreme insolubility of cellulose. A biphasic NaCl–H2O–tetrahydrofuran (THF) system was studied, in which most of the pure microcrystalline cellulose (M-cellulose, 96.6 % conversion at 220 °C) and that contained in actual biomass were converted. Nearly half of the O6?H???O3 intermolecular hydrogen bonds could be broken by THF in the H2O–THF co-solvent system, whereas the cleavage of O2?H???O6 intramolecular hydrogen bonds by H2O was significantly inhibited. In the NaCl–H2O–THF system, THF could significantly promote the effects of both H2O and NaCl on the disruption of O2?H???O6 and O3?H???O5 intramolecular hydrogen bonds, respectively. In addition, THF could protect and transfer the cellulose-derived products to the organic phase by forming hydrogen bonds between the oxygen atom in THF and the hydrogen atom of C4?OH in the glucose or aldehyde group in 5-hydroxymethylfurfural (HMF), which can lead more NaCl to combine with the -OH of M-cellulose and further disrupt hydrogen bonding in M-cellulose, thereby improving the yield of small molecular weight products (especially HMF) and further promoting the dissolution of cellulose. As a cheap and reusable system, NaCl–H2O–THF system may be a promising approach for the dissolution and further conversion of cellulose in lignocellulosic biomass without any enzymes, ionic liquids, or conventional catalysts.
- Jiang, Zhicheng,Zhao, Pingping,Li, Jianmei,Liu, Xudong,Hu, Changwei
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p. 397 - 405
(2018/01/03)
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- Three-step cascade over a single catalyst: Synthesis of 5-(ethoxymethyl)furfural from glucose over a hierarchical lamellar multi-functional zeolite catalyst
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The synthesis of hierarchical lamellar zeolites with a controlled meso-/microporous morphology and acidity is an expanding area of research interest for a wide range of applications. Here, we report a one-step synthesis of a hierarchical meso-/microporous
- Bai, Yuanyuan,Wei, Lu,Yang, Mengfei,Chen, Huiyong,Holdren, Scott,Zhu, Guanghui,Tran, Dat T.,Yao, Chunli,Sun, Runcang,Pan, Yanbo,Liu, Dongxia
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p. 7693 - 7705
(2018/05/14)
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- Phenolic compounds from Belamcanda chinensis seeds
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Two new sucrose derivatives, namely, belamcanosides A (1) and B (2), together with five other known compounds (3-7), were isolated from the seeds of Belamcanda chinensis (L.) DC. Their structures were identified based on spectroscopic data. Especially, the absolute configurations of fructose and glucose residues in 1 and 2 were assigned by acid hydrolysis, followed by derivatization and gas chromatography (GC) analysis. Among the known compounds, (-)-hopeaphenol (3), (+)-syringaresinol (4), and quercetin (5), were isolated from B. chinensis for the first time. In addition, biological evaluation of 1 and 2 against cholesterol synthesis and metabolism at the gene level was carried out. The results showed that compounds 1 and 2 could regulate the expression of cholesterol synthesis and metabolism-associated genes, including 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), squalene epoxidase (SQLE), low density lipoprotein receptor (LDLR), and sortilin (SORT1) genes in HepG2 cells.
- Song, Ying-Ying,Liu, Ying,Yan, Yong-Ming,Lu, Xi-Feng,Cheng, Yong-Xian
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- A Chromium Hydroxide/MIL-101(Cr) MOF Composite Catalyst and Its Use for the Selective Isomerization of Glucose to Fructose
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A metal–organic framework (MOF)-based catalyst, chromium hydroxide/MIL-101(Cr), was prepared by a one-pot synthesis method. The combination of chromium hydroxide particles on and within Lewis acidic MIL-101 accomplishes highly selective conversion of gluc
- Guo, Qiang,Ren, Limin,Kumar, Prashant,Cybulskis, Viktor J.,Mkhoyan, K. Andre,Davis, Mark E.,Tsapatsis, Michael
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supporting information
p. 4926 - 4930
(2018/03/27)
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- Sucrose derivatives, preparation method of same, and application thereof as anti-cancer medicine
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The invention relates to the technical field of medicines, and particularly provides a series of new-structure sucrose derivatives, on which hydroxyl groups are esterified by isovaleric acid, and a preparation method of same, and an application of the sucrose derivatives in preparation of anti-cancer medicines. The sucrose derivative is separated from a Compositae Ainsliaea plant, Ainsliaea yunnanensis Franch. The chemical structure of the sucrose derivative is represented as the formula (I). The sucrose derivative has significant cytotoxic activity to human lung adenocarcinoma cell A549 and can be used for preparing anti-cancer medicines.
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Paragraph 0059; 0062
(2017/12/28)
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- Dynamic formation of nanostructured particles from vesicles via invertase hydrolysis for on-demand delivery
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The unique multicompartmental nanostructure of lipid-based mesophases can be triggered, on-demand, in order to control the release of encapsulated drugs. In this study, these nanostructured matrices have been designed to respond to a specific enzyme, invertase, an enzyme which catalyses the hydrolysis of sucrose. The effect of two sugar esters upon the phase behaviour of two different lipids which form cubic phases, phytantriol and monolinolein, was investigated. Factors affecting the hydrolysis of the sucrose headgroup are discussed in terms of the molecular structure of the sugar surfactant and also its ability to incorporate into the lipid bilayer. By hydrolysing the incorporated sugar esters, a dynamic change in mesophase nanostructure from vesicles to a cubic phase was observed. This phase change resulted in the triggered release of an encapsulated model drug, fluorescein. This investigation demonstrates, for the first time, that changes on a molecular level by subtly controlling the hydrophilic and hydrophobic features of an amphiphilic additive at the interface by enzymatic hydrolysis can result in a global change in the system and so paves the way towards the design and development of lipid-based matrices which are responsive to specific enzymes for the controlled delivery of pharmaceutically active molecules or functional foods.
- Fong, Wye-Khay,Sánchez-Ferrer, Antoni,Ortelli, Francesco Giovanni,Sun, Wenjie,Boyd, Ben J.,Mezzenga, Raffaele
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p. 4368 - 4377
(2017/01/29)
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- Insights into the Kinetics and Reaction Network of Aluminum Chloride-Catalyzed Conversion of Glucose in NaCl-H2O/THF Biphasic System
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We performed a systematic experimental kinetics study on AlCl3-catalyzed conversion of glucose to 5-hydroxymethylfurfural (HMF) in NaCl-H2O/tetrahydrofuran (THF) biphasic solvent. The kinetics model covers an extensive reaction network including the parallel and tandem reactions of isomerization, dehydration, decomposition, and polymerization from glucose. The accuracy of the model was verified by a parity plot and statistical significance analysis of the kinetic parameters. A deliberate insight into the intrinsic kinetic properties (reaction rate constant and apparent activation energy) of each subreaction elaborates the regulatory role of THF and NaCl on reaction pathways within the network. That is, THF suppresses the rehydration, degradation, and polymerization of HMF to unwanted byproducts, inhibits fructose-to-HMF dehydration and fructose-to-humins polymerization, but promotes the generation of formic acid (FA) from the direct degradation of both glucose and fructose by facilitating the generation of [Glc/Fru + H-H2O-FA]+ species without formation of levulinic acid (LA); while NaCl promotes the dehydration and polymerization of fructose, decelerates the glucose-to-fructose isomerization, and effectively suppresses glucose-to-humins polymerization. The suppression role of NaCl on glucose conversion may come from the inhibition on mutarotation and ring opening from glucose due to the existence of a hydrogen bond between (C6)O-H on glucose and Cl- ion. The Br?nsted acid (HCl) from the hydrolysis of AlCl3 is responsible for direct glucose/fructose-to-FA degradation, HMF-to-humins polymerization, and HMF-to-FA/LA rehydration. The Lewis acidic [Al(OH)2(aq)]+ species is active for the reversible glucose-to-fructose isomerization and direct HMF-to-FA degradation, whereas glucose/fructose-to-humins polymerization and fructose-to-HMF dehydration are both Br?nsted and Lewis acid-catalyzed. This work highlights a deep understanding of the complicated reaction network in the acid-catalyzed conversion of glucose to HMF in a biphasic solvent.
- Tang, Jinqiang,Zhu, Liangfang,Fu, Xing,Dai, Jinhang,Guo, Xiawei,Hu, Changwei
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p. 256 - 266
(2017/06/07)
-
- Mechanism for the formation and growth of carbonaceous spheres from sucrose by hydrothermal carbonization
-
We report a new three-step mechanism for the formation and growth of carbonaceous spheres by hydrothermal carbonization of saccharides using sucrose as a precursor material. Carbonaceous spheres with small diameters and narrow size distribution were synthesized via a rapid heating route, and a notable phenomenon of a sudden drop in the mean diameter of the carbonaceous spheres at low concentration with the extension of time was observed. The morphology, chemical structure of carbonaceous spheres and the chemical composition of residual solutions were analysed by field emission scanning electron microscope (FESEM), Fourier transform infrared spectroscopy (FT-IR) and solution 13C nuclear magnetic resonance (NMR) respectively. Based on these results, evolution of solid products is clearly revealed. The formation contains two stages, and oversaturation of primary particles attributed to autocatalysis of fructose by the yielded acid (formic acid) results in the appearance of large amounts of carbonaceous spheres in the second stage of formation, which accounts for the sudden drop in mean diameter.
- Qi, Yujie,Zhang, Mu,Qi, Lin,Qi, Yang
-
p. 20814 - 20823
(2016/03/04)
-
- Glucose to Fructose Isomerization in Aqueous Media over Homogeneous and Heterogeneous Catalysts
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Isomerization of glucose to fructose is an important reaction with numerous applications in terms of biomass valorization. The reaction is catalyzed enzymatically but may also proceed under alkaline conditions, in which case it is accompanied by low selectivity and formation of byproducts. Solid Lewis acid and basic catalytic materials are being studied as alternative catalysts. In this work, the isomerization of glucose to fructose in aqueous media over homogeneous and heterogeneous catalysts has been investigated. The effect of polar aprotic solvents and their mixtures with water on glucose conversion and fructose selectivity was also studied. Sodium aluminate (NaAlO2) has been proven to be very effective, resulting in high fructose yield (52.1 %) and high selectivity (84.8 %). Among the various solid catalysts tested, MgO afforded glucose conversion of 44 %, with 75.8 % and 33.4 % fructose selectivity and yield, respectively, when the isomerization reaction was conducted in neat H2O.
- Marianou, Asimina A.,Michailof, Chrysoula M.,Pineda, Antonio,Iliopoulou, Eleni F.,Triantafyllidis, Kostas S.,Lappas, Angelos A.
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p. 1100 - 1110
(2016/04/05)
-
- The effects of emulsion on sugar dehydration to 5-hydroxymethylfurfural in a biphasic system
-
Alkyl/amino functionalized silica nanoparticles to create an emulsion in a biphasic system for sugar dehydration to HMF were successfully developed. As a proof-of-concept, more than 10% increase of HMF yield and 20% increase of selectivity were achieved for both fructose and glucose dehydrations in the emulsion system as compared to the conventional biphasic system. The excellent recyclability of the nanoparticles also further widens the potential of the biphasic system to be scaled up for industrial application.
- Teong, Siew Ping,Yi, Guangshun,Zeng, Huaqiang,Zhang, Yugen
-
supporting information
p. 3751 - 3755
(2015/07/15)
-
- Reactivity of metal catalysts in glucose-fructose conversion
-
A joint experimental and computational study on the glucose-fructose conversion in water is reported. The reactivity of different metal catalysts (CrCl3, AlCl3, CuCl2, FeCl3, and MgCl2) was analyzed. Experimentally, CrCl3 and AlCl3 achieved the best glucose conversion rates, CuCl2 and FeCl3 were only mediocre catalysts, and MgCl2 was inactive. To explain these differences in reactivity, DFT calculations were performed for various metal complexes. The computed mechanism consists of two proton transfers and a hydrogen-atom transfer; the latter was the rate-determining step for all catalysts. The computational results were consistent with the experimental findings and rationalized the observed differences in the behavior of the metal catalysts. To be an efficient catalyst, a metal complex should satisfy the following criteria: moderate Bronsted and Lewis acidity (pKa=4-6), coordination with either water or weaker σ donors, energetically low-lying unoccupied orbitals, compact transition-state structures, and the ability for complexation of glucose. Thus, the reactivity of the metal catalysts in water is governed by many factors, not just the Lewis acidity.
- Loerbroks, Claudia,Van Rijn, Jeaphianne,Ruby, Marc-Philipp,Tong, Qiong,Schüth, Ferdi,Thiel, Walter
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p. 12298 - 12309
(2015/03/31)
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- Catalytic activity and stability of hydrophobic Mg-Al hydrotalcites in the continuous aqueous-phase isomerization of glucose into fructose
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The aqueous-phase isomerization of glucose into fructose, catalyzed by Mg-Al hydrotalcites, has been investigated under batch and continuous conditions. A commercial hydrotalcite with a hydrophobic surface modification and two hydrophilic hydrotalcites in carbonate form, or with OH- anions in the interlayer space, served as catalysts. With the hydrophobic hydrotalcite a lower conversion but superior selectivity to fructose could be demonstrated, reaching above 92% selectivity at 30% conversion. The observed by-products confirm retroaldolization of glucose and fructose as the main side reactions causing catalyst deactivation via adsorption. Additionally, acidic degradation products such as lactic acid cause neutralization of the hydrotalcites facilitating leaching of the Mg2+ ions. Fructose contributes a greater extent to by-product formation. Applying continuous operation conditions, fructose is removed from the reaction mixture. Therefore, by-product formation is notably suppressed and catalyst stability increases. During 70 to 100 h time-on-stream a slow deactivation of the hydrophobic hydrotalcite occurs. Regeneration can be achieved via calcination and treatment in an aqueous sodium n-dodecyl sulfate solution to introduce dodecyl sulfate anions to the interlayer space of the hydrotalcite, restoring the hydrophobic material properties.
- Delidovich,Palkovits
-
p. 4322 - 4329
(2015/01/09)
-
- Niobium-containing hydroxyapatites as amphoteric catalysts: Synthesis, properties, and activity
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We present here a new class of Nb-containing catalysts offering both acid and base functionalities thanks to the hydroxyapatite (HAP) structure, which acts as a host matrix for guest niobium species. Incorporation of Nb has led to samples with strengthened amphoteric properties with a prevalence of acid or basic sites depending on the synthesis procedure. Nb-containing HAP samples (12-14 wt % of Nb) have been synthesized by coprecipitation in water and in alcoholic solutions and by impregnation starting from different precursors. The intrinsic and effective acid and base properties have been measured, and a series of mass and surface characterizations have been performed to determine the Nb content, its oxidation state as well as its morphologic, structural, and electronic properties. The performances of the samples have been studied in several reactions of liquid-solid heterogeneous catalysis in batch or fixed tubular reactors working in the recirculation mode on the basis of the known catalytic features of Nb, including hydrolysis, acid-catalyzed isomerization, and selective oxidation reactions.
- Carniti, Paolo,Gervasini, Antonella,Tiozzo, Cristina,Guidotti, Matteo
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p. 469 - 479
(2014/03/21)
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- Structures of acylated sucroses from the flower buds of Prunus mume
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Seven new acylated sucroses, mumeoses P-V, were isolated from the flower buds of Prunus mume, cultivated in Zhejiang province, China. Their chemical structures were elucidated on the basis of chemical and physicochemical evidence. Moreover, mumeoses C, D,
- Fujimoto, Katsuyoshi,Nakamura, Seikou,Matsumoto, Takahiro,Ohta, Tomoe,Yoshikawa, Masayuki,Ogawa, Keiko,Kashiwazaki, Eri,Matsuda, Hisashi
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p. 481 - 487
(2014/08/05)
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- Integrated catalytic process for biomass conversion and upgrading to C 12 furoin and alkane fuel
-
Report herein is an integrated catalytic process for conversion and upgrading of biomass feedstocks into 5,5′-dihydroxymethyl furoin (DHMF), through self-coupling of 5-hydroxymethyl furfural (HMF) via organocatalysis, and subsequently into n-C12H26 alkane fuel via metal-acid tandem catalysis. The first step of the process involves semicontinuous organocatalytic conversion of biomass (fructose, in particular) to the high-purity HMF. N-Heterocyclic carbenes (NHCs) are found to catalyze glucose-to-fructose isomerization, and the relatively inexpensive thiazolium chloride [TM]Cl, a Vitamin B1 analog, catalyzes fructose dehydration to HMF of good purity (>99% by HPLC), achieving a constant HMF yield of 72% over 10 semicontinuous extraction batch runs. Crystallization of the crude HMF from toluene yields the spectroscopically and analytically pure HMF as needle crystals. The second step of the process is the NHC-catalyzed coupling of C 6 HMF produced by the semicontinuous process to C12 DHMF; the most effective organic NHC catalyst produces DHMF in 93% or 91% isolated yield with an NHC loading of 0.70 mol % or 0.10 mol % at 60°C for 3 h under solvent-free conditions. The third step of the process converts C12 DHMF to linear alkanes via hydrodeoxygenation. With a bifunctional catalyst system consisting of Pd/C + acetic acid + La(OTf)3 at 250°C and 300 psi H2 for 16 h, DHMF has been transformed to liquid hydrocarbon fuel (78% alkanes), with a 64% selectivity to n-C12H26 and an overall C/H/O % ratio of 84/11/5.0.
- Liu, Dajiang,Chen, Eugene Y.-X.
-
p. 1302 - 1310
(2014/05/20)
-
- ISOMERISATION OF C4-C6 ALDOSES WITH ZEOLITES
-
The present invention relates to isomerization of C4-C6 aldoses to their corresponding C4-C6 ketoses. In particular, the invention concerns isomerization of C4-C6 aldoses over solid zeolite catalysts free of any metals other than aluminum, in the presence of suitable solvent(s) at suitable elevated temperatures. C6 and C5 aldose sugars such as glucose and xylose, which are available in large amounts from biomass precursors, are isomerized to fructose and xylulose respectively, in a one or two-step process over inexpensive commercially available zeolite catalysts, containing aluminum as the only metal in the catalyst. The ketoses obtained are used as sweeteners in the food and/or brewery industry, or treated to obtain downstream platform chemicals such as lactic acid, HMF, levulinic acid, furfural, MMHB, and the like. FIG. 7
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-
Page/Page column 15-22
(2014/03/25)
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- Biomolecular characterization of the levansucrase of erwinia amylovora, a promising biocatalyst for the synthesis of fructooligosaccharides
-
Erwinia amylovora is a plant pathogen that affects Rosaceae, such as apple and pear. In E. amylovora the fructans, produced by the action of a levansucrase (EaLsc), play a role in virulence and biofilm formation. Fructans are bioactive compounds, displaying health-promoting properties in their own right. Their use as food and feed supplements is increasing. In this study, we investigated the biomolecular properties of EaLsc using HPAEC-PAD, MALDI-TOF MS, and spectrophotometric assays. The enzyme, which was heterologously expressed in Escherichia coli in high yield, was shown to produce mainly fructooligosaccharides (FOSs) with a degree of polymerization between 3 and 6. The kinetic properties of EaLsc were similar to those of other phylogenetically related Gram-negative bacteria, but the good yield of FOSs, the product spectrum, and the straightforward production of the enzyme suggest that EaLsc is an interesting biocatalyst for future studies aimed at producing tailor-made fructans.
- Caputi, Lorenzo,Nepogodiev, Sergey A.,Malnoy, Mickael,Rejzek, Martin,Field, Robert A.,Benini, Stefano
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p. 12265 - 12273
(2014/01/06)
-
- Efficient isomerization of glucose to fructose over zeolites in consecutive reactions in alcohol and aqueous media
-
Isomerization reactions of glucose were catalyzed by different types of commercial zeolites in methanol and water in two reaction steps. The most active catalyst was zeolite Y, which was found to be more active than the zeolites beta, ZSM-5, and mordenite. The novel reaction pathway involves glucose isomerization to fructose and subsequent reaction with methanol to form methyl fructoside (step 1), followed by hydrolysis to re-form fructose after water addition (step 2). NMR analysis with 13C-labeled sugars confirmed this reaction pathway. Conversion of glucose for 1 h at 120 C with H-USY (Si/Al = 6) gave a remarkable 55% yield of fructose after the second reaction step. A main advantage of applying alcohol media and a catalyst that combines Bronsted and Lewis acid sites is that glucose is isomerized to fructose at low temperatures, while direct conversion to industrially important chemicals like alkyl levulinates is viable at higher temperatures.
- Saravanamurugan, Shunmugavel,Paniagua, Marta,Melero, Juan A.,Riisager, Anders
-
supporting information
p. 5246 - 5249
(2013/05/22)
-
- NMR structural study of fructans produced by Bacillus sp. 3B6, bacterium isolated in cloud water
-
Bacillus sp. 3B6, bacterium isolated from cloud water, was incubated on sucrose for exopolysaccharide production. Dialysis of the obtained mixture (MWCO 500) afforded dialyzate (DIM) and retentate (RIM). Both were separated by size exclusion chromatography. RIM afforded eight fractions: levan exopolysaccharide (EPS), fructooligosaccharides (FOSs) of levan and inulin types with different degrees of polymerization (dp 2-7) and monosaccharides fructose:glucose = 9:1. Levan was composed of two components with molecular mass ~3500 and ~100 kDa in the ratio 2.3:1. Disaccharide fraction contained difructose anhydride DFA IV. 1-Kestose, 6-kestose, and neokestose were identified as trisaccharides in the ratio 2:1:3. Fractions with dp 4-7 were mixtures of FOSs of levan (2,6-βFruf) and inulin (1,2-βFruf) type. DIM separation afforded two dominant fractions: monosaccharides with fructose: glucose ratio 1:3; disaccharide fraction contained sucrose only. DIM trisaccharide fraction contained 1-kestose, 6-kestose, and neokestose in the ratio1.5:1:2, penta and hexasaccharide fractions contained FOSs of levan type (2,6-βFruf) containing α-glucose. In the pentasaccharide fraction also the presence of a homopentasaccharide composed of 2,6-linked βFruf units only was identified. Nystose, inulin (1,2-βFruf) type, was identified as DIM tetrasaccharide. Identification of levan 2,6-βFruf and inulin 1,2-βFruf type oligosaccharides in the incubation medium suggests both levansucrase and inulosucrase enzymes activity in Bacillus sp. 3B6.
- Matulová, Mária,Husárová, Slavomíra,Capek, Peter,Sancelme, Martine,Delort, Anne-Marie
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experimental part
p. 501 - 507
(2011/04/22)
-
- Rates of spontaneous cleavage of glucose, fructose, sucrose, and trehalose in water, and the catalytic proficiencies of invertase and trehalas
-
The half-lives for spontaneous hydrolysis of trehalose and sucrose at 25 °C are 6.6 × 106 years and 440 years. The half-lives for decomposition of the hydrolysis products glucose and fructose are 96 years and 70 days, respectively. Whereas sucrose and trehalose differ by a factor of 15000 in their rates of uncatalyzed hydrolysis, the reactions catalyzed by invertase (EC 3.2.1.26) and trehalase (EC 3.2.1.28) proceed at similar rates. Accordingly, the attainments of invertase as a catalyst are modest, but the rate enhancement and catalytic proficiency produced by trehalase approach the high levels achieved by polysaccharide hydrolases. Copyright
- Wolfenden, Richard,Yuan, Yang
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p. 7548 - 7549
(2008/12/22)
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- Glucose production from saccharides using layered transition metal oxide and exfoliated nanosheets as a water-tolerant solid acid catalyst
-
The layered transition-metal oxide HNbMoO6 is demonstrated to exhibit remarkable catalytic performance for the hydrolysis of saccharides such as sucrose, cellobiose, starch, and cellulose, attributable to water tolerance and the facile accessibility of saccharides into the strong acidic interlayer gallery of the solid. The Royal Society of Chemistry.
- Takagaki, Atsushi,Tagusagawa, Caio,Domen, Kazunari
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scheme or table
p. 5363 - 5365
(2009/03/11)
-
- A METHOD FOR INDUSTRIAL PRODUCTION OF BIOCATALYSTS IN THE FORM OF ENZYMES OR MICROORGANISMS IMMOBILIZED IN POLYVINYL ALCOHOL GEL, THEIR USE AND DEVICES FOR THEIR PRODUCTION
-
A method for the industrial production of the biocatalysts with biologically active material in the form of immobilized enzymes or microorganisms which are immobilized into the polyvinyl alcohol gel, and their use based on the fact, that the active biological material, formed by the mixture of free native or pretrated (aggregated) enzyme catalyst, or production microorganism, or part of them, and the polyvinyl alcohol gel, is used for their industrial production, the mixture is gelated and shaped in a stream of drying air at the temperature of 800C to 150C, considering the extent of the biologically active material, at the biocatalyst geometrical ratio of the surface to the volume kept larger than 7 mm'1, and consequently thus prepared biocatalysts can be cultivated or stored and then use in biotechnological processes in the conditions, which ensure given biotechnological process higher productivity, higher production and enzymatic stability, long-term and repeated usage or definable process control with consequence easy separation of the biocatalyst. The industrial production device, providing optimization of the biological carrier volume and surface in dependence on biologically active material extent, consisting of a casting mechanism (17) mounted in front of a drying channel (2), through which a continuous conveyor belt (1) runs, is equipped with at least one casting head (17) with two rows of casting needle injectors connected to a pressure tempered tank (15) and a compressor (16), the conveyor belt (1) and a drying system - the source (4) of a drying air, which is blown by means of ventilator into an air distribution system (6) with incorporated heating elements (5), which runs into the upper drying channel (2), and further the lower final drying channel (3) and a reswelling tank (7), between which a wiping and collecting device (9) is mounted, designed on the basis of mechanical wiping and high-pressure rinse, which is connected to a pipeline with integrated high-pressure pump (10) and low-pressure pump (11) running into a collecting reservoir (8) with cooling and further a rinse box (13) for continuous conveyor belt (1) final cleaning by jets connected to a low- pressure pump (14), which is connected to a rinse tank (12) by pipeline.
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Page/Page column 36; 37
(2008/06/13)
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- SUCRASE ACTIVITY INHIBITOR, GLUCOAMYLASE ACTIVITY INHIBITOR AND FOOD AND FEED CONTAINING THE SAME
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The invention provides a sucrase activity inhibitor and a glucoamylase activity inhibitor comprising one or more saccharides selected from the group consisting of palatinose, trehalulose and palatinit. Further, the invention provides a food or feed comprising the sucrose activity inhibitor and/or the glucoamylase activity inhibitor.
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-
Page/Page column 10-11
(2008/06/13)
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- Glucose reactions with acid and base catalysts in hot compressed water at 473 K
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The effects of the homogeneous catalysts (H2SO4 and NaOH) and heterogeneous catalysts (TiO2 and ZrO2) on glucose reactions were examined in hot compressed water (473 K) by a batch-type reactor. From the homogeneous catalyst studies, we confirmed that the acid catalyst promoted dehydration, while isomerization of glucose to fructose was catalyzed by alkali. Anatase TiO2 was found to act as an acid catalyst to promote formation of 5-hydroxymethylfuraldehyde (HMF). Zirconia (ZrO2) was a base catalyst to promote the isomerization of glucose. The effects of the additives were also confirmed through fructose reactions.
- Watanabe, Masaru,Aizawa, Yuichi,Iida, Toru,Aida, Taku M.,Levy, Caroline,Sue, Kiwamu,Inomata, Hiroshi
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p. 1925 - 1930
(2007/10/03)
-
- Studies on absorption and hydrolysis of ethyl α-D-glucoside in rat intestine
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Ethyl α-D-glucoside (α-EG) is normally contained in Sake, which has been taken by Japanese people since ancient times. In this study, the intestinal absorption of α-EG was investigated using rat everted intestinal sac. Furthermore, the α-EG hydrolytic activity in rat intestine was compared with disaccharides hydrolytic activities, and the effects of α-EG on disaccharides hydrolysis were examined using crude enzyme preparation from rat intestinal acetone powder. Glucose liberated from α-EG was detected in a serosal solution of everted rat intestinal sac, but it was only less than 4% of absorbed intact α-EG. α-EG absorption into small intestinal tissue was reduced by elimination of sodium ion from the mucosal solution or under the presence of phlorizin. The hydrolytic activity for α-EG was detected in crude enzyme preparation from rat intestinal acetone powder, but it showed a low value as compared to those for disaccharides. α-EG showed mixed type inhibition for maltose and sucrose hydrolysis, but inhibitory concentrations of α-EG required for 50% inhibition for the maltose and sucrose hydrolysis were higher than those of arabinose and acarbose. In conclusion, a small amount of α-EG was hydrolyzed and most of it was absorbed via SGLT1 as an intact form in the rat small intestine, and the inhibitory effect of α-EG on disaccharides hydrolysis was weak.
- Mishima, Tomoyuki,Tanaka, Keiko,Tsuge, Haruhito,Sugita, Jun,Nakahara, Michio,Hayakawa, Takashi
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p. 7257 - 7261
(2007/10/03)
-
- METHOD FOR SELECTIVE CARBOHYDRATE OXIDATION USING SUPPORTED GOLD CATALYSTS
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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.
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-
Page/Page column 42-44
(2010/02/09)
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- A PROCESS FOR PRODUCING A CARBOHYDRATE COMPOSITION
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The present invention concerns a process for the production of a carbohydrate composition from lactose comprising a mixture of 10-50% galactose, 0-48% glucose, 1-25% fructose, 1-48% gluconic acid and 0-25% unconverted lactose and non-lactose di- and oligo-saccharides; and compositions produced by the process as well as food and drink containing the compositions.
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-
Page/Page column 10-11
(2008/06/13)
-
- Kinetics of hydrolysis of fructooligosaccharides in mineral-buffered aqueous solutions: Influence of pH and temperature
-
High-performance anion exchange chromatography coupled with a pulsed amperometric detection system (HPAEC-PAD) was used to evaluate the extent of chemical hydrolysis of three fructooligosaccharides (FOS) including 1-kestose (β-D-Fru-(2→1)2-α-D-glucopyranoside, GF2), nystose (β-D-Fru-(2→1)3-α-D-glucopyranoside, GF3), and fructofuranosylnystose (β-D-Fru-(2→1)4-α-D-glucopyranoside, GF4). A kinetic study was carried out at 80, 90, 100, 110, and 120 °C in aqueous solutions buffered at pH values of 4.0, 7.0, and 9.0. Under each experimental condition, the determination of the respective amounts of reactants and hydrolysis products showed that FOS hydrolysis obeyed pseudo-first-order kinetics as the extent of hydrolysis, which decreased at increasing pH values, increased with temperature. The three oligomers were found to be degraded mainly under acidic conditions, and at the highest temperature value (120 °C), a quick and complete acid degradation of each FOS was observed. Using the Arrhenius equation, rate constants, half-life values, and activation energies were calculated and compared with those obtained from sucrose under the same experimental conditions. It appeared that the hydrolysis of FOS took place much more easily at acidic pH than at neutral or basic pH values.
- L'Homme,Arbelot,Puigserver,Biagini, Anne
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p. 224 - 228
(2007/10/03)
-
- Reaction kinetics and modeling of the enzyme-catalyzed production of lactosucrose using β-fructofuranosidase from Arthrobacter sp. K-1
-
Lactosucrose synthesis from sucrose and lactose was carried out by using β-fructofuranosidase from Arthrobacter sp. K-1. The transfructosylation mechanism was found to be of an ordered bi-bi type in which sucrose was bound first to the enzyme and lactosucrose was released last. Hydrolysis side-reaction experiments indicated that the reactions were uncompetitively inhibited by glucose and lactose, while no inhibition by fructose was apparent. The overall reaction rates were formulated. The reaction rate constants, equilibrium constant, and dissociation and Michaelis constants were determined at 35°C and 50°C by fitting the experimental concentration changes with the calculated values by a nonlinear least-square method. The average relative derivation for the concentrations was 9.67%. The kinetic parameters were also calculated for 43°C and 60°C by assuming the Arrhenius law, and the course of reaction was predicted. The obtained reaction rate equations well represented the concentration changes during the experiment at all temperatures.
- Pilgrim, Axel,Kawase, Motoaki,Ohashi, Masayasu,Fujita, Koki,Murakami, Kazufumi,Hashimoto, Kenji
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p. 758 - 765
(2007/10/03)
-
- Efficient catalytic hydrolysis of disaccharides by cerium(IV) ion at pH 7
-
CeIV(NH4)2(NO3)6 effectively catalyses hydrolysis of various disaccharides such as sucrose, maltose, lactose, and cellobiose at pH 7.0, and activation energy for sucrose hydrolysis was found to be 14.4 kcal mol-1, which is remarkably smaller than that by 0.18 N HCI, 30 kcal mo-1.
- Ishida, Hitoshi,Seri, Kei-Ichi
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p. 379 - 380
(2007/10/03)
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- Preparative Scale Organic Synthesis using a Kitchen Microwave Oven
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A new and practical continuous flow procedure for preparative scale organic synthesis using a kitchen microwave oven as the heat source has been developed and successfully applied to five different organic reactions.
- Chen, Shui-Tein,Chiou, Shyh-Horng,Wang, Kung-Tsung
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p. 807 - 809
(2007/10/02)
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