Production Of Fructose Research Articles

Fabrication of Mg-Al hydrotalcite/carbon nanotubes hybrid base catalysts for efficient production of fructose from glucose

Efficient and selective glucose-to-fructose isomerization is a crucial step in biorefinery, usually catalyzed by Lewis acid or Brønsted base catalyst. However, inferior selectivity of Lewis acid and low conversion of Brønsted base hamper the practical application. Herein, a Mg-Al hydrotalcite/carbon nanotubes hybrid catalyst was prepared using bottom-up strategy for glucose isomerization in water. Tunable textural properties and basicity of the catalyst was achieved by tailoring Mg/Al ratio while the introduction of CNT could further change the morphology and surface electronic properties, resulting in a desirable active site exposure and less particle aggregation. Additionally, DFT and in-situ FTIR experiment demonstrated glucose conversion proceed via base-catalyzed route, and the increase of Mg/Al ratio as well as the electron deficiency of the surface would enhance the interaction between glucose and catalyst, which was conducive to the adsorption and deprotonation of glucose. As a result, a fructose yield of 40%, which is close to thermodynamic equilibrium yield, was obtained over HT5:1/CNT in water within 2 h.

Production of fructose and gluconic acid from sucrose with cross-linked yeast cell walls expressing glucose oxidase on the surface

Saccharomyces cerevisiae, known as bakers’ yeast, is one of the most utilized yeasts in industry. Several enzymes that are naturally produced by yeast, such as invertase and catalase, combined with heterologously expressed glucose oxidase (GOx), represent the enzyme machinery for fructose and gluconic acid production. Therefore, we have used yeast cell walls with expressed glucose oxidase as a platform for crosslinking with invertase and catalase to create biocatalyst cells for the high yield sucrose conversion. Using 5% (w/v) suspension of cross-linked yeast cell walls in 0.15 M sucrose solution, 1.86 g L−1 h−1 of gluconic acid has been obtained using wt-GOx, while mutant A2-GOx produced 2.91 g L−1 h−1 of gluconic acid. Increasing the concentration of modified yeast cells walls to 10% (w/v) we were able to obtain almost 100% conversion of glucose to gluconic acid using A2-GOx in the first cycle. Reusing the modified cells walls in three consecutive cycles, conversion dropped to approximately 70% using A2-GOx and 40% using wt-GOx.

The Sweet and Salty Dietary Face of Hypertension and Cardiovascular Disease in Lebanon.

According to the World Health Organization (WHO), an estimated 1.28 billion adults aged 30–79 years worldwide have hypertension; and every year, hypertension takes 7.6 million lives. High intakes of salt and sugar (mainly fructose from added sugars) have been linked to the etiology of hypertension, and this may be particularly true for countries undergoing the nutrition transition, such as Lebanon. Salt-induced hypertension and fructose-induced hypertension are manifested in different mechanisms, including Inflammation, aldosterone-mineralocorticoid receptor pathway, aldosterone independent mineralocorticoid receptor pathway, renin-angiotensin system (RAS), sympathetic nervous system (SNS) activity, and genetic mechanisms. This review describes the evolution of hypertension and cardiovascular diseases (CVDs) in Lebanon and aims to elucidate potential mechanisms where salt and fructose work together to induce hypertension. These mechanisms increase salt absorption, decrease salt excretion, induce endogenous fructose production, activate fructose-insulin-salt interaction, and trigger oxidative stress, thus leading to hypertension. The review also provides an up-to-date appraisal of current intake levels of salt and fructose in Lebanon and their main food contributors. It identifies ongoing salt and sugar intake reduction strategies in Lebanon while acknowledging the country’s limited scope of regulation and legislation. Finally, the review concludes with proposed public health strategies and suggestions for future research, which can reduce the intake levels of salt and fructose levels and contribute to curbing the CVD epidemic in the country.

Front Cover: Isomerization of Glucose‐to‐Fructose in Water over a Continuous Flow Reactor using Ca−Al Mixed Oxide as Heterogeneous Catalyst (ChemCatChem 3/2022)

The Front Cover highlights a new continuous catalytic process to isomerize glucose into fructose in aqueous media under mild reaction conditions by using hydrotalcite-derived Ca-Al-O mixed oxide as heterogeneous catalyst. In their Full Paper, M. Ventura et al. present one of the first successful examples in the literature of a continuous non-enzymatic route for this reaction. Furthermore, the search for adequate operational conditions to optimize the process and maximize fructose production is thoroughly described. As a result, high glucose conversion and fructose yields are achieved with an affordable Ca-Al-based material as stable catalyst. More information about the work carried out by researchers of Instituto de Tecnología Química (UPV – CSIC) of Valencia, Spain can be found in the Full Paper by M. Ventura et al.

The Contribution of Dietary Fructose to Non-alcoholic Fatty Liver Disease.

Fructose, especially industrial fructose (sucrose and high fructose corn syrup) is commonly used in all kinds of beverages and processed foods. Liver is the primary organ for fructose metabolism, recent studies suggest that excessive fructose intake is a driving force in non-alcoholic fatty liver disease (NAFLD). Dietary fructose metabolism begins at the intestine, along with its metabolites, may influence gut barrier and microbiota community, and contribute to increased nutrient absorption and lipogenic substrates overflow to the liver. Overwhelming fructose and the gut microbiota-derived fructose metabolites (e.g., acetate, butyric acid, butyrate and propionate) trigger the de novo lipogenesis in the liver, and result in lipid accumulation and hepatic steatosis. Fructose also reprograms the metabolic phenotype of liver cells (hepatocytes, macrophages, NK cells, etc.), and induces the occurrence of inflammation in the liver. Besides, there is endogenous fructose production that expands the fructose pool. Considering the close association of fructose metabolism and NAFLD, the drug development that focuses on blocking the absorption and metabolism of fructose might be promising strategies for NAFLD. Here we provide a systematic discussion of the underlying mechanisms of dietary fructose in contributing to the development and progression of NAFLD, and suggest the possible targets to prevent the pathogenetic process.

Coordinated regulation of photosynthesis and sugar metabolism in guar increases tolerance to drought

Drought is an inevitable environmental constraint to plant productivity. Cyamopsis tetragonoloba commonly known as guar is an economically important crop used as vegetable, and for its seed gum. We examined the complicated network of sugar interactions and regulation of photosynthesis in four varieties of guar subjected to water stress. A presumptive mechanistic approach considering growth and development, physiological attributes, and gene expression facet was evaluated. Decreased photosynthesis results in reduced equivalents (NADPH2+) for CO2 assimilation through the Calvin cycle, which furthermore generates oxidative stress and accumulates antioxidant enzymes. The scavenging of ROS was more in RGC-986 and HG-563 than RGC-471 and Varsha variety. Chlorophyll fluorescence studies indicate a significant reduction in values of photochemical quantum yield, electron transport rates of photosystem I and II, photochemical quantum yield due to regulated energy dissipation, and fraction of energy that is passively dissipated in the form of heat and fluorescence. For a better understanding of the behavioural pattern in response to drought, we studied the relative gene expression of enzymes regulating the sugar metabolism. The study suggested that at the onset of drought the genes of PS II machinery and Calvin cycle were co-ordinately regulated efficiently in RGC-986 and HG-563 than in RGC-471 and Varsha. However, the gene expression levels of sugar transporter enzymes in leaves of guar varieties increased under water stress. Gene expression analysis of sugar metabolic pathways reveals the increased production of glucose, fructose and fructan in HG-563 and RGC-986 in comparison to Varsha and RGC-471. These results indicate that induced level of sugar metabolic genes under drought leads to the activation of its tolerance mechanism. Furthermore, this study significantly highlights that how carbon flux is diverted to sugar metabolism via a sequence of molecular events in relation to its physiological status, under water deficit conditions in guar leaves.

Conversion of organosolv pretreated hardwood biomass into 5-hydroxymethylfurfural (HMF) by combining enzymatic hydrolysis and isomerization with homogeneous catalysis

BackgroundOver the last few years, valorization of lignocellulosic biomass has been expanded beyond the production of second-generation biofuels to the synthesis of numerous platform chemicals to be used instead of their fossil-based counterparts. One such well-researched example is 5-hydroxymethylfurfural (HMF), which is preferably produced by the dehydration of fructose. Fructose is obtained by the isomerization of glucose, which in turn is derived by the hydrolysis of cellulose. However, to avoid harsh reaction conditions with high environmental impact, an isomerization step towards fructose is necessary, as fructose can be directly dehydrated to HMF under mild conditions. This work presents an optimized process to produce fructose from beechwood biomass hydrolysate and subsequently convert it to HMF by employing homogeneous catalysis.ResultsThe optimal saccharification conditions were identified at 10% wt. solids loading and 15 mg enzyme/gsolids, as determined from preliminary trials on pure cellulose (Avicel® PH-101). Furthermore, since high rate glucose isomerization to fructose requires the addition of sodium tetraborate, the optimum borate to glucose molar ratio was determined to 0.28 and was used in all experiments. Among 20 beechwood solid pulps obtained from different organosolv pretreatment conditions tested, the highest fructose production was obtained with acetone (160 °C, 120 min), reaching 56.8 g/100 g pretreated biomass. A scale-up hydrolysis in high solids (25% wt.) was then conducted. The hydrolysate was subjected to isomerization eventually leading to a high-fructose solution (104.5 g/L). Dehydration of fructose to HMF was tested with 5 different catalysts (HCl, H3PO4, formic acid, maleic acid and H-mordenite). Formic acid was found to be the best one displaying 79.9% sugars conversion with an HMF yield and selectivity of 44.6% and 55.8%, respectively.ConclusionsOverall, this work shows the feasibility of coupling bio- and chemo-catalytic processes to produce HMF from lignocellulose in an environmentally friendly manner. Further work for the deployment of biocatalysts for the oxidation of HMF to its derivatives could pave the way for the emergence of an integrated process to effectively produce biobased monomers from lignocellulose.

Magnesium Impregnated on NaX Zeolite Synthesized from Cogon Grass Silica for Fast Production of Fructose via Microwave-Assisted Catalytic Glucose Isomerization

Fructose is a crucial intermediate in the production of several chemical platforms. Fructose is mainly produced from glucose isomerization either through immobilized enzymes or heterogeneous catalysts using a conventional heating source, and this is time-consuming. Thus, this work discloses a fast production of fructose via microwave-assisted catalytic glucose isomerization using Mg catalysts supported on NaX zeolite from cogon grass silica. The catalysts were prepared by the impregnation of magnesium nitrate solution and subsequently transformed into MgO on NaX by calcination. The effect of 3, 6 and 9 wt.% Mg content on NaX on the performance of glucose isomerized to fructose was tested at 90 °C for 15 min. The best catalyst was selected for studying the effect of reaction times of 5, 15, 30 and 60 min. Results from X-ray diffraction (XRD), N2 sorption and CO2 temperature-programmed desorption (CO2-TPD) suggested that crystallinity, surface area and micropore volume decrease but basicity increases with Mg content. The X-ray photoelectron spectroscopy (XPS) result confirmed the presence of mixed phases of MgO and Mg2CO3 in all catalysts. The glucose conversion enhanced with the Mg loading but the fructose yield gave the highest value with Mg of 6 wt.%, probably due to the tuning of high active sites and surface area. The greatest fructose selectivity and yield (71.9% and 25.8%) were obtained within 15 min by microwave-assisted catalytic reaction, shorter than the reported value in the literature, indicating a suitable reaction time. Mg (6 wt.%)/NaX catalyst preserves the original catalytic performance up to three cycles, indicating that it is a promising catalyst for fructose production.

The role of thrifty genes in the origin of alcoholism: A narrative review and hypothesis.

In this narrative review, we present the hypothesis that key mutations in two genes, occurring 15 and 10million years ago (MYA), were individually and then collectively adaptive for ancestral humans during periods of starvation, but are maladaptive in modern civilization (i.e., "thrifty genes"), with the consequence that these genes not only increase our risk today for obesity, but also for alcoholism. Both mutations occurred when ancestral apes were experiencing loss of fruit availability during periods of profound climate change or environmental upheaval. The silencing of uricase (urate oxidase) activity 15MYA enhanced survival by increasing the ability for fructose present in dwindling fruit to be stored as fat, a consequence of enhanced uric acid production during fructose metabolism that stimulated lipogenesis and blocked fatty acid oxidation. Likewise, a mutation in class IV alcohol dehydrogenase ~10MYA resulted in a remarkable 40-fold increase in the capacity to oxidize ethanol (EtOH), which allowed our ancestors to ingest fallen, fermenting fruit. In turn, the EtOH ingested could activate aldose reductase that stimulates the conversion of glucose to fructose, while uric acid produced during EtOH metabolism could further enhance fructose production and metabolism. By aiding survival, these mutations would have allowed our ancestors to generate more fat, primarily from fructose, to survive changing habitats due to the Middle Miocene disruption and also during the late-Miocene aridification of East Africa. Unfortunately, the enhanced ability to metabolize and utilize EtOH may now be acting to increase our risk for alcoholism, which may be yet another consequence of once-adaptive thrifty genes.

Fructose Metabolism and Cardiac Metabolic Stress.

Cardiovascular disease is one of the leading causes of mortality in diabetes. High fructose consumption has been linked with the development of diabetes and cardiovascular disease. Serum and cardiac tissue fructose levels are elevated in diabetic patients, and cardiac production of fructose via the intracellular polyol pathway is upregulated. The question of whether direct myocardial fructose exposure and upregulated fructose metabolism have potential to induce cardiac fructose toxicity in metabolic stress settings arises. Unlike tightly-regulated glucose metabolism, fructose bypasses the rate-limiting glycolytic enzyme, phosphofructokinase, and proceeds through glycolysis in an unregulated manner. In vivo rodent studies have shown that high dietary fructose induces cardiac metabolic stress and functional disturbance. In vitro, studies have demonstrated that cardiomyocytes cultured in high fructose exhibit lipid accumulation, inflammation, hypertrophy and low viability. Intracellular fructose mediates post-translational modification of proteins, and this activity provides an important mechanistic pathway for fructose-related cardiomyocyte signaling and functional effect. Additionally, fructose has been shown to provide a fuel source for the stressed myocardium. Elucidating the mechanisms of fructose toxicity in the heart may have important implications for understanding cardiac pathology in metabolic stress settings.

Crystalline fructose production: a conceptual design with experimental data and operating cost analysis

Fructose is a monosaccharide of great interest to industries. The easiest way to produce crystalline fructose from its aqueous solution is adding ethanol to the solution, which narrows the large metastable zone width and reduces the solution viscosity and the fructose solubility in water, increasing yields of crystallization. Studies in the literature though are limited to those of solubility, kinetics, and characterization of product, not including economic or environmental effects. This study addresses steps to integrate the whole productive system. A thermal analysis of the solution showed that exposing the solution to temperatures equal or above 104 °C has adverse effects on crystallization and should be avoided. The experimental study also showed that using 90 wt.% ethanol aqueous solution leads to the best yields and a well-defined morphology of fructose crystals – yields of 97%, roundness of 7.25 and mean size of 95.00 µm in the best experiment. However, the cost of ethanol represents almost 80% of the gross income of the plant, if ethanol is not recycled. An integrated system is then proposed considering the separation and reuse of ethanol and mother-liquor. Among those evaluated, the optimal operating conditions conducts to a minimal cost of 99.40 US$/tonne of fructose, which has a value of 796 US$/tonne.

Exo-inulinase production from Aspergillus fumigatus NFCCI 2426: purification, characterization, and immobilization for continuous fructose production.

Aspergillus fumigatus was found to produce thermostable exo-inulinase (EC 3.8.1.80; 38 U/ml) on inulin-rich infusions. Exo-inulinase (14.6 U/mg) was immobilized on glutaraldehyde activated Ca-alginate beads for continuous generation of fructose by hydrolyzing sucrose, chicory, and dandelion substrates. Immobilization of enzyme was confirmed by microscopic and spectroscopic techniques. The exo-inulinase was purified using ion-exchange (1.30-folds) and size-exclusion chromatography (2.71-folds). The purified exo-inulinase showed 64kDa band on gel and was optimally active at 60°C and pH 6.0. Kinetic constants, Km and Vmax of purified exo-inulinase, were 5.88mM and 1.66µM/min, respectively, and its relative activity was found to be enhanced (125.8%) in the presence of calcium ion. Immobilized preparation was utilized for continuous generation of fructose from chicory juice (26 to 70%) and dandelion root extracts (16 to 24%) by recycling upto five cycles, respectively. In comparison to other sweeteners, such as sucrose, fructose is considered as a healthy alternative. The present study demonstrated the use of immobilized exo-inulinase in continuous generation of fructose from some underutilized plant sources that can be used in food industry. PRACTICAL APPLICATION: Thermostable exo-inulinase produced by A. fumigatus was immobilized on calcium alginate matrix and was employed for continuous hydrolysis of chicory juice and dandelion root extract for generation of fructose syrup.

Fructose separation from sorghum syrup by using HPLC approach: a review

Liquid sugar available today is usually the result of dissolving granulated sugar using hot water. Sorghum syrup can be obtained from the concentrate without involving crystallization, centrifugation, sieving and drying and dissolving processes. However, the sorghum syrup produced from the concentrate still containing complex sugar components such as sucrose, sugar, fructose and others. This review was examined the separation of fructose from sorghum syrup using the HPLC approach. Compared with artificial sweeteners or sugar derivative products such as dextrose, maltodextrin, sorbitol, saccharin, sucralose, and xylitol, sorghum syrup still has lower economic value. The manufacture of these sugar derivatives generally uses chemical processes such as chlorination of sucralose, hydrogenation of xylitol or enzymatic processes and fermentation of fructose. Chemical processes in general can pose a danger to consumer health, while enzymatic and biological processes require high operational costs and complex processes of enzyme and cell separation such corn fructose production. Chromatography is a technology for separating complex mixtures such as sorghum concentrates to obtain separate components, such as fructose syrup and byproducts. On a laboratory scale, sugar fractionation or fructose purification is generally carried out using High Performance Liquid Chromatography (HPLC) with the Carbopac ion exchange column as the stationary phase and ultrapure water as the mobile phase. The industrial scale fractionation in the food sector is still applied to palm oil processing. This is a great opportunity to conduct research related to the components of sorghum concentrates using chromatography column fractionation technology to obtain pure fructose with greater process efficiency and economics.

Determination of inulin in the herbal mixtures by GC-MS method

The herbal mixtures due to the wide range of biologically active substances can influence on various links of the pathogenetic mechanism of development of diabetes mellitus and its complications. The carbohydrates, especially inulin, deserve the particular attention through their hypoglycemic, hypolipidemic, anticholesterolemic and detoxifying activities. The aim of the study was to investigate the content of inulin in the herbal mixtures No. 3, No. 4, No. 7, No. 13 and No. 19, which are used in folk medicine for the prevention and treatment of diabetes mellitus type 2 in Ukraine. The quantity content of inulin was defined by the difference between fructose as a product of enzymatic hydrolysis and fructose, a constituent of sucrose and free fructose, taking into account the empirical factor for the conversion of fructose from inulin. The carbohydrates were separated by gas chromatography-mass spectrometry after conversion into volatile derivatives as aldononitrile acetate. According to the results, the herbal mixture No. 3 contains 458.97 mg/g of inulin, the herbal mixture No. 4 – 99.21 mg/g, the herbal mixture No. 7 – 139.93 mg/g, the herbal mixture No. 13 – 203.84 mg/g, the herbal mixture No. 19 – 359.65 mg/g. The availability of inulin and its high content in the investigated herbal mixtures due to the presence of inulin-containing medicinal plants, such as Cichorium intubus roots (mixtures No. 3 and No. 13), Taraxacum officinale roots (mixtures No. 3, No. 7 and No. 19), Arctium lappa roots (mixture No. 4), Inula helenium rhizome with roots (mixture No. 7).

Fructose Metabolism in Cancer.

The interest in fructose metabolism is based on the observation that an increased dietary fructose consumption leads to an increased risk of obesity and metabolic syndrome. In particular, obesity is a known risk factor to develop many types of cancer and there is clinical and experimental evidence that an increased fructose intake promotes cancer growth. The precise mechanism, however, in which fructose induces tumor growth is still not fully understood. In this article, we present an overview of the metabolic pathways that utilize fructose and how fructose metabolism can sustain cancer cell proliferation. Although the degradation of fructose shares many of the enzymes and metabolic intermediates with glucose metabolism through glycolysis, glucose and fructose are metabolized differently. We describe the different metabolic fates of fructose carbons and how they are connected to lipogenesis and nucleotide synthesis. In addition, we discuss how the endogenous production of fructose from glucose via the polyol pathway can be beneficial for cancer cells.

Exposure to non-continuous rotating magnetic field induces metabolic strain-specific response of Komagataeibacter xylinus

Application of electromagnetic field in biotechnological processes is considered a promising tool to enhance their effectiveness and to control microbe-derived synthesis of desired compounds. The current work analyzes impact of non-continuous rotating magnetic field (RMF) on ability of two Komagataeibacter xylinus strains to produce bacterial cellulose (BC) and to consume fructose and ethanol. Exposure of K. xylinus ATCC 53524 to the RMF of 50 Hz frequency resulted in a statistically significant 10 % increase in BC yield and significant drop of fructose consumption comparing to untreated control setting. In turn, K. xylinus ATCC 53582 cultures, under the exposure to the RMF, showed no significant improvement in BC production but higher level of fructose and ethanol utilization, comparing to RMF-untreated strain. Exposure to the RMF, regardless the Komagataeibacter strain scrutinized, increased the cell proliferation rate, which was reflected in greater cell density and viability as compared to the non-exposed cultures. The results of our study show potential of RMF to improve efficiency of BC production, but at the same time they indicate that aforementioned potential is strictly related to specific K. xylinus strain applied.

Prospective production of fructose and single cell protein from date palm waste

Abstract Background Fructose and single cell protein are important products for the food market. Abundant amounts of low-grade dates worldwide are annually wasted. In this study, highly concentrated fructose syrups and single cell protein were obtained through selective fermentation of date extracts by Saccharomyces cerevisiae. Results The effect of air flow (0.1, 0.5, 0.75, 1, 1.25 and 1.5 vvm) and pH (4.5, 4.8, 5, 5.3 and 5.6) was investigated. Higher air flow led to lower fructose yield. The optimum cell mass production of 10 g/L was achieved at air flow of 1.25 vvm with the fructose yield of 91%. Similar cell mass production was obtained in the range pH of 5.0–5.6, while less cell mass was obtained at pH less than 5. Controlling the pH at 4.5, 5.0 and 5.3 failed to improve the production of cell mass which were 5.6, 5.9 and 5.4 g/L respectively; however, better fructose yield was obtained. Conclusions Extension of the modified Gompertz enabled excellent predictions of the cell mass, fructose production and fructose fraction. The proposed model was also successfully validated against data from literatures. Thus, the model will be useful for wide application of biological processes. How to cite: Putra MD, Abasaeed AE, Al-Zahrani SM. Prospective production of fructose and single cell protein from date palm waste. Electron J Biotechnol 2020;48. https://doi.org/10.1016/j.ejbt.2020.09.007 .

Prebiotic fructooligosaccharides obtained from escarole (Cichorium endivia L.) roots

Inulin and fructooligosaccharides (FOS) are fructans a reserve polysaccharides that have a great economic interest in the food and pharmaceutical industries. Cichorium endivia, also known as “escarole”, belongs to the family Asteraceae and normally is used as a salad, forage crops and raw material for the production of fructose. The objective of this work was to extract, characterize chemically, and evaluate the prebiotic activity in vitro from C. endivia roots FOS. By colorimetric assays, we to determined its chemical composition with 85.4% of total sugars containing 72.2% of fructose. HSQC-Q NMR was used to determine the monosaccharide composition. The NMR and off-line ESI-MS analysis showed that C. endivia FOS has a degree of polymerization equal to 6 and 7, respectively. In vitro prebiotic test showed that the same was fermented by all probiotic bacteria evaluated and the results showed that C. endivia FOS is a promising source of prebiotic fructans.

Inulinase immobilization onto glutaraldehyde activated duolite XAD for the production of fructose from inulin

Abstract In the present practice, central composite rotatable design (CCRD) of response surface methodology (RSM) was used to optimise inulinase immobilization onto duolite XAD by gultaraldehyde (GA) cross-linking. After optimization, at optimal levels of variables (GA concentration 1.59%, enzyme coupling time 12 h, GA treatment time 4.0 h and enzyme load 22.7 IU), maximal inulinase activity yield and immobilization yield attained was 53.2% and 76.45%, respectively. A very narrow difference between predicted and experimental results confirms the authenticity of the present model. Besides, coefficient of determination (R2) value approaching one also authenticates the affluence of the designed polynomial model. Maximum hydrolysis (79.5%) of inulin by immobilized biocatalyst was achieved under agitation (125 rpm) mode of hydrolysis. Fructose production from inulin using inulinase immobilized onto duolite XAD was successfully performed for 10 consecutive batch cycles.

Fructose Production and Metabolism in the Kidney.

Understanding fructose metabolism might provide insights to renal pathophysiology. To support systemic glucose concentration, the proximal tubular cells reabsorb fructose as a substrate for gluconeogenesis. However, in instances when fructose intake is excessive, fructose metabolism is costly, resulting in energy depletion, uric acid generation, inflammation, and fibrosis in the kidney. A recent scientific advance is the discovery that fructose can be endogenously produced from glucose under pathologic conditions, not only in kidney diseases, but also in diabetes, in cardiac hypertrophy, and with dehydration. Why humans have such a deleterious mechanism to produce fructose is unknown, but it may relate to an evolutionary benefit in the past. In this article, we aim to illuminate the roles of fructose as it relates to gluconeogenesis and fructoneogenesis in the kidney.