470-23-5Relevant articles and documents
Hybrid Organic–Inorganic Anatase as a Bifunctional Catalyst for Enhanced Production of 5-Hydroxymethylfurfural from Glucose in Water
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.
, p. 872 - 880 (2018)
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
Direct conversion of inulin to 5-hydroxymethylfurfural in biorenewable ionic liquids
Hu, Suqin,Zhang, Zhaofu,Zhou, Yinxi,Song, Jinliang,Fan, Honglei,Han, Buxing
, p. 873 - 877 (2009)
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
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
Deng, Weiping,Zhu, Enze,Liu, Mi,Zhang, Qinghong,Wang, Ye
, p. 43131 - 43141 (2014)
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.
Effect of CO2 on conversion of inulin to 5-hydroxymethylfurfural and propylene oxide to 1,2-propanediol in water
Wu, Suxiang,Fan, Honglei,Xie, Ye,Cheng, Yan,Wang, Qian,Zhang, Zhaofu,Han, Buxing
, p. 1215 - 1219 (2010)
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.
NMR for direct determination of Km and Vmax of enzyme reactions based on the Lambert W function-analysis of progress curves
Exnowitz, Franziska,Meyer, Bernd,Hackl, Thomas
, p. 443 - 449 (2012)
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.
Two-step biosynthesis of D-allulose via a multienzyme cascade for the bioconversion of fruit juices
Li, Chao,Li, Lei,Feng, Zhiyuan,Guan, Lijun,Lu, Fuping,Qin, Hui-Min
, (2021/04/27)
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.
Linking Molecular Behavior to Macroscopic Properties in Ideal Dynamic Covalent Networks
Marco-Dufort, Bruno,Iten, Ramon,Tibbitt, Mark W.
supporting information, p. 15371 - 15385 (2020/10/20)
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.
