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Glucose To Fructose

(535f) Selective Glucose To Fructose Isomerization Over Modified Zirconium Uio?66 In Alcohol Media

(535f) Selective Glucose To Fructose Isomerization Over Modified Zirconium Uio?66 In Alcohol Media

Wednesday, October 31, 2018 - 2:15pm-2:36pm Biomass-derived feedstocks are alternative carbon sources to fossil fuels to produce value-added chemicals. Glucose isomerization to fructose is a key reaction for the conversion of sugars into these platform chemicals such as 5-hydroxymethylfurfural (HMF). Despite the use of zeolites as Lewis-acid catalysts for glucose isomerization, metal-organic frameworks (MOFs) have drawn attention due to their high tunability and density of active sites. In this work, we used a modified zirconium UiO-66, a highly stable MOF, as a catalyst for glucose isomerization reaction in alcohol media. The fructose selectivity is shown to change depending on solvent choice drastically. A combined effect of adsorption and solvation leads to the formation of alkyl-glucosides in depletion of fructose when methanol or ethanol are used. The use of 1-propanol as a solvent leads to selectivities of 72 % and 10 % in fructose and mannose, respectively at 82 % glucose conversion. We also demonstrate by 13C NMR that the sugars adsorb onto UiO-66 in a closed form and that fructose is formed by an intramolecular C2-C1 hydride transfer mechanism. [1] Dorneles de Mello, M.; Tsapatsis, M. ChemCatChem 10.1002/cctc.201800371. Continue reading >>

Metabolism - Reason For Conversion Of Glucose To Fructose In Glycolysis - Biology Stack Exchange

Metabolism - Reason For Conversion Of Glucose To Fructose In Glycolysis - Biology Stack Exchange

Reason for conversion of glucose to fructose in glycolysis In glycolysis, glucose is converted to glucose 6-phosphate so it can not diffuse out of the membrane. Then it is converted to fructose 6-phosphate. Why is this? Perhaps it makes it less stable so it is easier to break down into pyruvate? That is just a guess, is anyone able to provide more information about this? Don't guess. Please do some research before posting basic questions that can be answered by reading a text book of biochemistry. For example Chapter 16 of Berg et al. online. David Aug 30 '17 at 21:20 However as I do not think either of the answers (including the one you accepted) are adequate, the point is less obvious than I imagined. I have therefore provided my own answer. David Sep 6 '17 at 13:45 In glycolysis, free energy (sequestered in the form of ATP) is derived from the splitting of glucose. One mechanistic explanation for the conversion of glucose to fructose is that it facilitates splitting of glucose via (reverse) aldol condensation (in the aldolase reaction) as aldol condensations are are 'facilitated' by having a carbonyl group next to the site of cleavage.. See this great article for a much better description than what I have given: weizmann.ac.il/plants/Milo/sites/plants.Milo/files/publications/ xusr Sep 6 '17 at 19:51 Avoiding diffusion is one reason to phosphorylate glucose, the other is that it is removed from the osmotic balance between inside and outside of the membrane, so it can be transported at a high rate. The Glucose-6-phosphate can then be used as a substrate for different pathways, namely glycolysis and the pentose phosphate way, and (depending on the organism) also be converted into glycogen and starch for further storage. The reason for the phosphorylation lies further d Continue reading >>

Sucrose, Glucose And Fructose

Sucrose, Glucose And Fructose

Sucrose, glucose and fructose are all simple carbohydrates or simple sugars. Glucose and fructose are individual sugar units and are also called monosaccharides. Sucrose is a sugar molecule made up of both glucose and fructose so sucrose is called a disaccharide. We get our sugar naturally from whole foods and also in processed foods where sugar is added. Although sucrose, glucose and fructose are all natural sugars and taste sweet on our tongues, theres a huge difference in the way they are metabolized in our bodies. Our bodies like to use glucose as its energy source (glucose is the preferred energy source for your muscles and brain) so we will use any glucose we eat and also break down most carbohydrates into glucose which is then either stored or used immediately. Insulin assists glucose to get into your cells to be used for energy so it is secreted when the body detects high levels of glucose in your blood but not when theres high levels of sucrose or fructose. Virtually every cell in your body is able to metabolize glucose. Eating too much sugar causes high blood levels of glucose which in time damages your insulin metabolism. Diabetes damages blood vessels all over your body. High blood sugars cause heart disease, kidney failure, blindness, poor circulation to your feet leading to amputations, slow wound healing and nerve damage. Fructose is also a naturally occurring sugar in many fruits and vegetables but fructoseis metabolized primarily in your liver. Fructose is used to produce energy through glycolysis. However, unlike glucose, fructose is also involved in lipogenesis which is how fat is created. Fructose is involved in the growth of fat-filled plaques that accumulate in your arteries causing cardiovascular disease and strokes. Too much fructose also create Continue reading >>

Sugar Swap: Human Brain Converts Glucose Into Fructose

Sugar Swap: Human Brain Converts Glucose Into Fructose

Sugar Swap: Human Brain Converts Glucose into Fructose The human brain can produce the sugar fructose, a new small study finds. Researchers found that the brain can convert one form of sugar, called glucose, into another form, called fructose . People who have too much fructose in their diet may face an increased risk of conditions such as type 2 diabetes and obesity. Previous research has suggested that fructose and glucose act differently in the brain. For example, studies have shown that glucose sends signals of fullness to the brain, but fructose does not, lead study author Dr. Janice Hwang, an assistant professor of medicine at Yale University, said in a statement. But although it was clear that fructose was found in the brain, a lingering question remained: How does the sugar get into the brain, particularly in high concentrations? [ 10 Things You Didn't Know About the Brain ] Earlier work showed that glucose enters the brain by crossing the blood-brain barrier, the researchers wrote in the study. And although fructose is also thought to be able to cross this barrier, the sugar is found in "exceedingly" low concentrations in the blood, because it is broken down by the liver, according to the study. This means that very little fructose would be available to cross into the brain. In the new study, published today (Feb. 23) in the journal JCI Insight, eight healthy people had their brains scanned while they received intravenous infusions of glucose over a 4-hour period. The scans measured the levels of glucose and fructose in the participants' brains using a special type of imaging. During the 4-hour period, the researchers also periodically took blood samples to measure the participants' blood glucose levels , and adjusted the infusions to make sure that the partic Continue reading >>

Reactor Design For The Enzymatic Isomerization Of Glucose To Fructose

Reactor Design For The Enzymatic Isomerization Of Glucose To Fructose

, Volume 7, Issue5 , pp 199204 | Cite as Reactor design for the enzymatic isomerization of glucose to fructose A comprehensive methodology is presented for the design of reactors using immobilized enzymes as catalysts. The design is based on material balances and rate equations for enzyme action and decay and considers the effect of mass transfer limitations on the expression of enzyme activity. The enzymatic isomerization of glucose into fructose with a commercial immobilized glucose isomerase was selected as a case study. Results obtained are consistent with data obtained from existing high-fructose syrup plants. The methodology may be extended to other cases, provided sound expressions for enzyme action and decay are available and a simple flow pattern within the reactor might be assumed. EnzymeWaste WaterMass TransferFructoseFlow Pattern These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves. substrate diffusivity within the catalyst particle number of enzyme half-lives used in the reactors apparent Michaelis constant f(K, Ks, Kp, s0) first-order thermal inactivation rate constant ratio of minimum to maximum process flowrate distance to the center of the spherical particle time elapsed between two successive charges of each reactor apparent initial reaction rate f(Km, s,Vm) dimensionless substrate concentration at equilibrium \(\theta = \frac{R}{3}\left( {\frac{{V_{_m } }}{{K_{_m } D}}} \right)^{1/2} \) This is a preview of subscription content, log in to check access. Unable to display preview. Download preview PDF. Hamilton, B.; Colton, C.; Cooney, C.: Glucose isomerase: A case study of enzyme-catalyzed process technology. In: Olson, A.; Cooney, A. (Eds.): Immobi Continue reading >>

Isomerization Of Glucose To Fructose. 2. Optimization Of Reaction Conditions In The Production Of High Fructose Syrup By Isomerization Of Glucose Catalyzed By A Whole Cell Immobilized Glucose Isomerase Catalyst

Isomerization Of Glucose To Fructose. 2. Optimization Of Reaction Conditions In The Production Of High Fructose Syrup By Isomerization Of Glucose Catalyzed By A Whole Cell Immobilized Glucose Isomerase Catalyst

Isomerization of glucose to fructose. 2. Optimization of reaction conditions in the production of high fructose syrup by isomerization of glucose catalyzed by a whole cell immobilized glucose isomerase catalyst Abstract: The well-known interconversion of aldoses to their corresponding ketoses was discovered more than a century ago, but has recently attracted renewed attention due to alternative application areas. Since the pioneering discovery, much work has been directed ... Saravanamurugan, Paniagua, Melero, and Riisager Abstract: 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 ... Abstract: The nature of the active aluminum species and their interaction with glucose in water are studied to establish a detailed mechanism for understanding AlCl3-catalyzed glucose-to-fructose isomerization. The combination of activity results with electrospray ... Abstract: The isomerization of glucose to fructose represents a key intermediate step in the conversion of cellulosic biomass to fuels and renewable platform chemicals, namely, 5-hydroxymethyl furfural (HMF), 2,5-furandicarboxylic acid (FDCA), and levulinic acid (... Abstract: We present the kinetic parameters and equilibrium constant of the enzymatic glucosefructose isomerization reaction with an immobilized glucose isomerase (IGI), Sweetzyme IT, using a batch stirred-tank reactor following the procedure developed by Dehkordi ... Marianou, Michailof, Ipsakis, Karakoulia, Kalogiannis, Yiannoulakis, Triantafyllidis, and Lappas Abstract: Fructose is one of the most important aldoses and has been gaining attention as the starting mate Continue reading >>

Fructose

Fructose

Fructose, or fruit sugar, is a simple ketonic monosaccharide found in many plants, where it is often bonded to glucose to form the disaccharide, sucrose. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into blood during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847.[4][5] The name “fructose” was coined in 1857 by the English chemist, William Allen Miller.[6] Pure, dry fructose is a sweet, white, odorless, crystalline solid, and is the most water-soluble of all the sugars.[7] Fructose is found in honey, tree and vine fruits, flowers, berries, and most root vegetables. Commercially, fructose is derived from sugar cane, sugar beets, and maize. Crystalline fructose is the monosaccharide, dried, ground, and of high purity. High-fructose corn syrup is a mixture of glucose and fructose as monosaccharides. Sucrose is a compound with one molecule of glucose covalently linked to one molecule of fructose. All forms of fructose, including fruits and juices, are commonly added to foods and drinks for palatability and taste enhancement, and for browning of some foods, such as baked goods. About 240,000 tonnes of crystalline fructose are produced annually.[8] As for any sugar, excessive consumption of fructose may contribute to insulin resistance, obesity,[9] elevated LDL cholesterol and triglycerides, leading to metabolic syndrome,[10][11][12] type 2 diabetes and cardiovascular disease.[13] The European Food Safety Authority stated that fructose is preferable over sucrose and glucose in sugar-sweetened foods and beverages because of its lower effect on postprandial blood sugar levels, and also noted that “high intakes of fructose may lead to metabolic complications such as dys Continue reading >>

Fructose Metabolism In Humans What Isotopic Tracer Studies Tell Us

Fructose Metabolism In Humans What Isotopic Tracer Studies Tell Us

Fructose metabolism in humans what isotopic tracer studies tell us 1Compliance, Archer Daniels Midland Company, 1001 North Brush College Road, Decatur, IL, 62521, USA Received 2012 Aug 3; Accepted 2012 Sep 24. Copyright 2012 Sun and Empie; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This article has been cited by other articles in PMC. Fructose consumption and its implications on public health are currently under study. This work reviewed the metabolic fate of dietary fructose based on isotope tracer studies in humans. The mean oxidation rate of dietary fructose was 45.0% 10.7 (mean SD) in non-exercising subjects within 36 hours and 45.8% 7.3 in exercising subjects within 23 hours. When fructose was ingested together with glucose, the mean oxidation rate of the mixed sugars increased to 66.0% 8.2 in exercising subjects. The mean conversion rate from fructose to glucose was 41% 10.5 (mean SD) in 36 hours after ingestion. The conversion amount from fructose to glycogen remains to be further clarified. A small percentage of ingested fructose (<1%) appears to be directly converted to plasma TG. However, hyperlipidemic effects of larger amounts of fructose consumption are observed in studies using infused labeled acetate to quantify longer term de novo lipogenesis. While the mechanisms for the hyperlipidemic effect remain controversial, energy source shifting and lipid sparing may play a role in the effect, in addition to de novo lipogenesis. Finally, approximately a quarter of ingested fructose can be converted into lactate within a few of hours. The reviewed Continue reading >>

Expeditious Isomerization Of Glucose To Fructose In Aqueous Media Over Sodium Titanate Nanotubes

Expeditious Isomerization Of Glucose To Fructose In Aqueous Media Over Sodium Titanate Nanotubes

Expeditious isomerization of glucose to fructose in aqueous media over sodium titanate nanotubes b Department of Chemistry, Indian Institute of Technology Hyderabad (IITH), Kandi, India c Dr S. S. Bhatnagar University Institute of Chemical Engineering & Technology, Panjab University, Chandigarh 160014, India Isomerization reaction of glucose to fructose over sodium titanate nanotubes (Na-TNTs) as a Lewis base catalyst was studied. Analytical instruments recorded the specific structural, textural and basic properties of the as-synthesized Na-TNTs. Furthermore, studying the catalytic isomerization performance of the Na-TNTs confirmed their high catalytic efficiency and suitability in aqueous media. The catalyst prompted rapid glucose isomerization within 2 min by achieving nearly half of the maximum yield, whereas with a prolonged reaction up to 15 min the maximum glucose conversion could be reached with 31.26% fructose yield and 65.26% selectivity under relatively lower operating conditions (100 C and 10% wt catalyst dose). However, the recyclability performance of the catalyst was not impressive due to the accelerated leaching of cations and surface retention of carbonaceous content, resulting in 16% reduced yield after 4 runs. A simple regeneration technique using NaOH led to the initial catalytic activity being totally regained. Overall, a titania-based catalyst (preferably nanotube structured sodium titanate) was shown as a potential catalyst for large-scale demonstration of glucose isomerization to achieve high fructose productivity. Please wait while we load your content... Something went wrong. Try again? Continue reading >>

Glucose-to-fructose Conversion At High Temperatures With Xylose (glucose) Isomerases From Streptomyces Murinus And Two Hyperthermophilic Thermotoga Species.

Glucose-to-fructose Conversion At High Temperatures With Xylose (glucose) Isomerases From Streptomyces Murinus And Two Hyperthermophilic Thermotoga Species.

Department of Chemical Engineering, North Carolina State University, Stinson Drive, Box 7905, Raleigh, North Carolina 27695-7905, USA. The conversion of glucose to fructose at elevated temperatures, as catalyzed by soluble and immobilized xylose (glucose) isomerases from the hyperthermophiles Thermotoga maritima (TMGI) and Thermotoga neapolitana 5068 (TNGI) and from the mesophile Streptomyces murinus (SMGI), was examined. At pH 7.0 in the presence of Mg(2+), the temperature optima for the three soluble enzymes were 85 degrees C (SMGI), 95 degrees to 100 degrees C (TNGI), and >100 degrees C (TMGI). Under certain conditions, soluble forms of the three enzymes exhibited an unusual, multiphasic inactivation behavior in which the decay rate slowed considerably after an initial rapid decline. However, the inactivation of the enzymes covalently immobilized to glass beads, monophasic in most cases, was characterized by a first-order decay rate intermediate between those of the initial rapid and slower phases for the soluble enzymes. Enzyme productivities for the three immobilized GIs were determined experimentally in the presence of Mg(2+). The highest productivities measured were 750 and 760 kg fructose per kilogram SMGI at 60 degrees C and 70 degrees C, respectively. The highest productivity for both TMGI and TNGI in the presence of Mg(2+) occurred at 70 degrees C, pH 7.0, with approximately 230 and 200 kg fructose per kilogram enzyme for TNGI and TMGI, respectively. At 80 degrees C and in the presence of Mg(2+), productivities for the three enzymes ranged from 31 to 273. A simple mathematical model, which accounted for thermal effects on kinetics, glucose-fructose equilibrium, and enzyme inactivation, was used to examine the potential for high-fructose corn syrup (HFCS) pro Continue reading >>

Fructose - An Overview | Sciencedirect Topics

Fructose - An Overview | Sciencedirect Topics

Fructose is a 6-carbon ketose found in fruit and honey as a monosaccharide, and in sucrose (a disaccharide of fructose and glucose). J.M. Johnson, F.D. Conforti, in Encyclopedia of Food Sciences and Nutrition (Second Edition) , 2003 Fructose is a monosaccharide. Fructose bonded with glucose, another monosaccharide, forms sucrose, or table sugar. Fructose also occurs naturally in abundance in fruits (Table 1) and in lesser amounts in tuberous vegetables such as onions and potatoes. These sources alone contribute some 4060% of an individual's total fructose intake. However, the major source of fructose as an ingredient in food is from the hydrolyzation of starch to glucose, which is then converted to fructose. (See CARBOHYDRATES | Classification and Properties.) Fruits are a rich source of mono- and disaccharides. Dates contain up to 48.5% sucrose, and dried figs contain a mixture of 30.9% fructose and 42.0% glucose. The sucrose content of most fruit and fruit juices is low, though some varieties of melons, peaches, pineapple, and tangerine contain 69% sucrose, and mango contains 11.6% sucrose. Reducing sugars (primarily a mixture of fructose and glucose) are the main soluble carbohydrate of most fruits and account for 70% of seedless raisins. Vegetables contain substantially less fructose and glucose than fruits, and the only significant source of sucrose is sugar beets. In the late 19th century corn or potato starch was hydrolyzed with dilute acid to yield glucose and dextrins for commercial purposes. In the 1940s, cornstarch was the primary choice for the production of glucose and the introduction of enzyme technology for hydrolysis reactions contributed to the development of glucose syrups to fructose syrups of specified glucose content. The conversion of glucose syr Continue reading >>

Organic Chemistry - How To Convert Glucose To Fructose - Chemistry Stack Exchange

Organic Chemistry - How To Convert Glucose To Fructose - Chemistry Stack Exchange

This conversion is done enzymatically on industrial scale using "glucose isomerase". ssavec Dec 16 '13 at 16:11 thank you! are there any other methods, more 'chemical' in nature? Shubham Dec 16 '13 at 17:06 Probably yes, but in general, all sugar chemistry is nasty, as the -OH groups are very similar and it is difficult to perform efficient synthesis. And impossible to do simple synthesis. ssavec Dec 17 '13 at 6:52 After searching on Google about Isomerization of Glucose to Fructose , you can find so many sources that explain the process. I think that this one is easy to understand among them. It explains that The isomerization of glucose to fructose is part of the glycolysis cycle that converts glucose to pyruvate. The way this is done is to isomerize the aldehyde (hemiacetal) glucose to the ketone (as a hemiacetal) fructose,and make another phosphate ester. The isomerization takes advantage of the ease of breakage of a C-H bond which involves a carbon next to a carbonyl carbon. This gives a clear Idea on the mechanism of Glucose Isomerage to fructose. :) Continue reading >>

Magnetically Separable Base Catalysts For Isomerization Of Glucose To Fructose

Magnetically Separable Base Catalysts For Isomerization Of Glucose To Fructose

Magnetically separable base catalysts for isomerization of glucose to fructose Author links open overlay panel QiangYang ShengfeiZhou TroyRunge We fabricate heterogeneous or magnetic base catalysts based on organic bases. The heterogeneous or magnetic bases are effective glucose isomerization catalysts. Accumulated by-products affect reusability of the heterogeneous base catalysts. The magnetic base catalysts show excellent stability and reusability. Isomerization of glucose to fructose is a key intermediate step for the biochemical conversion of lignocellulose to liquid fuels and chemicals through the sugar platform. This study demonstrates facile and general strategies to fabricate heterogeneous or magnetic base catalysts based on organic bases for the isomerization of glucose to fructose in water. The heterogeneous or magnetic base catalyst can achieve similar glucose-to-fructose yield and selectivity to homogenous organic base catalyst. The accumulated by-products influence the reusability of the heterogeneous base catalyst; however, the magnetic base catalyst shows excellent stability and reusability. Continue reading >>

Sucrose Vs Glucose Vs Fructose: What's The Difference?

Sucrose Vs Glucose Vs Fructose: What's The Difference?

Sucrose vs Glucose vs Fructose: What's the Difference? If youre trying to cut back on sugar, you may wonder whether the type of sugar matters. Sucrose, glucose and fructose are three types of sugar that contain the same number of calories gram for gram. Theyre all found naturally in fruits, vegetables, dairy products and grains but also added to many processed foods. However, they differ in their chemical structures, the way your body digests and metabolizes them and how they affect your health. This article examines the main differences between sucrose, glucose and fructose and why they matter. Sucrose is the scientific name for table sugar. Sugars are categorized as monosaccharides or disaccharides. Disaccharides are made up of two, linked monosaccharides and broken back down into the latter during digestion ( 1 ). Sucrose is a disaccharide consisting of one glucose and one fructose molecule, or 50% glucose and 50% fructose. Its a naturally occurring carbohydrate found in many fruits, vegetables and grains, but its also added to many processed foods, such as candy, ice cream, breakfast cereals, canned foods, soda and other sweetened beverages. Table sugar and the sucrose found in processed foods are commonly extracted from sugar cane or sugar beets. Sucrose tastes less sweet than fructose but sweeter than glucose ( 2 ). Glucose is a simple sugar or monosaccharide. Its your bodys preferred carb-based energy source ( 1 ). Monosaccharides are made up of one single unit of sugar and thus cannot be broken down into simpler compounds. Theyre the building blocks of carbohydrates . In foods, glucose is most commonly bound to another simple sugar to form either polysaccharide starches or disaccharides, such as sucrose and lactose ( 1 ). Its often added to processed foods in t Continue reading >>

How Does Glucose Convert Into Fructose? - Quora

How Does Glucose Convert Into Fructose? - Quora

Answered Nov 24, 2017 Author has 149 answers and 175.7k answer views Aside from glucose isomerase, as mentioned by Mr. Forday, theres another clinically relevant pathway called the polyol pathway, in which glucose is changed into sorbitol by aldose reductase, which is then converted into fructose by a certain sorbitol dehydrogenase. This may be important in humans, as in certain cells that express the second enzyme less, a buildup of sorbitol can lead to cellular damage. Originally Answered: How is glucose converted into fructose? Industrially, glucose is converted to fructose with glucose isomerase, a bacterial enzyme. The discovery of this enzyme and its industrial application has brought us into the world of high fructose corn syrup. In humans, conversion of glucose to fructose should not be confused with conversion of glucose 6-phosphate to fructose 6-phosphate in glycolysis. Instead, the polyol pathway is used, present mainly in seminal vesicles. Glucose is reduced to sorbitol by aldose reductase in the first step. The second step, catalyzed by sorbitol dehydrogenase, oxidizes sorbitol to fructose. 329 Views View Upvoters Not for Reproduction Originally Answered: How will glucose convert into fructose? It can happen in mammalian systems in the reversible second reaction of glycolysis (G6P <-> F6P) but generally does not happen in vivo due to the rapid conversion of F6P to F1,6 DP. Even though both are hexose (6 carbons) they have different configurations. 173 Views View Upvoters Not for Reproduction Quora User, Laborant Quality Control at Fertilizer Company (2003-present) If done in reactors in a factory it would be much simpler i guess but it happens in the human body too, and that is actually pretty complicated, reacquires multiple steps: The isomerization of gl Continue reading >>

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