Conversion Of D-glucose Research Articles

Identification of hyperthermophilic D-allulose 3-epimerase from Thermotoga sp. and its application as a high-performance biocatalyst for D-allulose synthesis.

D-Allulose 3-epimerase (DAE) is a vital biocatalyst for the industrial synthesis of D-allulose, an ultra-low calorie rare sugar. However, limited thermostability of DAEs hinders their use at high-temperature production. In this research, hyperthermophilic TI-DAE (Tm = 98.4 ± 0.7 ℃) from Thermotoga sp. was identified via in silico screening. A comparative study of the structure and function of site-directed saturation mutagenesis mutants pinpointed the residue I100 as pivotal in maintaining the high-temperature activity and thermostability of TI-DAE. Employing TI-DAE as a biocatalyst, D-allulose was produced from D-fructose with a conversion rate of 32.5%. Moreover, TI-DAE demonstrated excellent catalytic synergy with glucose isomerase CAGI, enabling the one-step conversion of D-glucose to D-allulose with a conversion rate of 21.6%. This study offers a promising resource for the enzyme engineering of DAEs and a high-performance biocatalyst for industrial D-allulose production.

Brewing alcohol 101: An undergraduate experiment utilizing benchtop NMR for quantification and process monitoring.

In recent years there has been a renewed interest in benchtop NMR. Given their lower cost of ownership, smaller footprint, and ease of use, they are especially suited as an educational tool. Here, a new experiment targeted at upper-year undergraduates and first-year graduate students follows the conversion of D-glucose into ethanol at low-field. First, high and low-field data on D-glucose are compared and students learn both the Hz and ppm scales and how J-coupling is field-independent. The students then acquire their own quantitative NMR datasets and perform the quantification using an Electronic Reference To Access In Vivo Concentration (ERETIC) technique. To our knowledge ERETIC is not currently taught at the undergraduate level, but has an advantage in that internal standards are not required; ideal for following processes or with future use in flow-based benchtop monitoring. Using this quantitative data, students can relate a simple chemical process (fermentation) back to more complex topics such as reaction kinetics, bridging the gaps between analytical and physical chemistry. When asked to reflect on the experiment, students had an overwhelmingly positive experience, citing agreement with learning objectives, ease of understanding the protocol, and enjoyment. Each of the respondents recommended this experiment as a learning tool for others. This experiment has been outlined for other instructors to utilize in their own courses across institutions, with the hope that a continued expansion of low-field NMR will increase accessibility and learning opportunities at the undergraduate level.

Production of d-glucaric acid with phosphoglucose isomerase-deficient Saccharomyces cerevisiae

d-Glucaric acid is a potential biobased platform chemical. Previously mainly Escherichia coli, but also the yeast Saccharomyces cerevisiae, and Pichia pastoris, have been engineered for conversion of d-glucose to d-glucaric acid via myo-inositol. One reason for low yields from the yeast strains is the strong flux towards glycolysis. Thus, to decrease the flux of d-glucose to biomass, and to increase d-glucaric acid yield, the four step d-glucaric acid pathway was introduced into a phosphoglucose isomerase deficient (Pgi1p-deficient) Saccharomyces cerevisiae strain. High d-glucose concentrations are toxic to the Pgi1p-deficient strains, so various feeding strategies and use of polymeric substrates were studied. Uniformly labelled 13C-glucose confirmed conversion of d-glucose to d-glucaric acid. In batch bioreactor cultures with pulsed d-fructose and ethanol provision 1.3 g d-glucaric acid L−1 was produced. The d-glucaric acid titer (0.71 g d-glucaric acid L−1) was lower in nitrogen limited conditions, but the yield, 0.23 g d-glucaric acid [g d-glucose consumed]−1, was among the highest that has so far been reported from yeast. Accumulation of myo-inositol indicated that myo-inositol oxygenase activity was limiting, and that there would be potential to even higher yield. The Pgi1p-deficiency in S. cerevisiae provides an approach that in combination with other reported modifications and bioprocess strategies would promote the development of high yield d-glucaric acid yeast strains.

Irreversible biosynthesis of D-Allulose from D-glucose in Escherichia coli through fine-tuning of carbon flux and cofactor regeneration engineering.

As a rare hexose with low calories and various physiological functions, D-allulose has drawn increasing attention. The current industrial production of D-allulose from D-fructose or D-glucose is achieved via epimerization based on the Izumoring strategy; however, the inherent reaction equilibrium during reversible reaction limits its high conversion yield. Although the conversion of D-fructose to D-allulose could be enhanced via phosphorylation-dephosphorylation mediated by metabolic engineering, biomass reduction and byproduct accumulation remain a largely unresolved issue. After modifying the glycolytic pathway of Escherichia coli and optimizing the whole-cell reaction condition, the engineered strain produced 7.57 ± 0.61 g L-1 D-allulose from 30 g L-1 D-glucose after 24 h of catalysis. By developing an ATP regeneration system for enhanced substrate phosphorylation, the cell growth inhibition was alleviated and D-allulose production increased by 55.3% to 11.76 ± 0.58 g L-1 (0.53 g g-1 ). Fine-tuning of carbon flux caused a 48% reduction in D-fructose accumulation to 1.47 ± 0.15 g L-1 . After implementing fed-batch co-substrate strategy, the D-allulose titer reached 15.80 ± 0.31 g L-1 (0.62 g g-1 ) with a D-glucose conversion rate of 84.8%. This study presented a novel strategy for high-yield D-allulose production from low-cost substrate. This article is protected by copyright. All rights reserved.

Comparative Kinetic and Pyrolytic Studies of d-Glucose Using Formulated Red Mud, Sand, and HZSM-5

The catalytic pyrolysis of d-glucose (DG) was conducted using a thermogravimetric analyzer (TGA) and formulated red mud (FRM) as the catalyst to determine the kinetic parameters of DG decomposition in the presence of the catalyst. The FRM reduced the overall activation energy (45.58–87.35 KJ/mol) of DG conversion compared to sand (45.27–112.00 KJ/mol). The trend of the frequency factor (A) for the catalytic pyrolysis (first-order reaction: 78.1–1.14 × 108 s–1) and non-catalytic pyrolysis (first-order reaction: 7.10–2.08 × 107 s–1) of DG was different, which indicated different reaction mechanisms. Compared to the sand and HZSM-5 catalyst, the FRM altered the thermal decomposition profile of the DG and promoted its decomposition at lower reaction temperatures. The thermogravimetric analyses showed that at 260 °C, the FRM catalyst converted more DG (50% conversion) than the HZSM-5 (44% conversion) and sand (35% conversion), which was in agreement with its activation energy. Furthermore, the DG decomposition was studied in a fixed-bed reactor using catalytic and non-catalytic pyrolysis conditions. The FRM promoted the formation of low-molecular-weight compounds (acetic acid and formic acid, CO2, formaldehyde, and CO) and hindered the formation of furans. The HZSM-5 catalyst promoted the formation of furans.

2,5-Diketo-D-Gluconate Hyperproducing Gluconobacter sphaericus SJF2-1 with Reporting Multiple Genes Encoding the Membrane-Associated Flavoprotein-Cytochrome c Complexed Dehydrogenases.

Gluconobacter sphaericus has not yet been used in biotransformation studies. In this study, G. sphaericus SJF2-1, which produces a diffusible pigment, was isolated from grape. The spent culture medium became dark black when the cells were grown in medium containing glucose and then autoclaved. This bacterium produced 2,5-diketo-D-gluconate (2,5-DKG) from D-glucose and D-gluconate. When 5% D-glucose was used, the conversion efficiency was approximately 52.4% in a flask culture. 2,5-DKG is a precursor of 2-keto-L-gulonic acid, which is a key intermediate in the industrial production of L-ascorbic acid. The complete genome sequence of G. sphaericus SJF2-1 was determined for the first time in the G. sphaericus species. The total size was 3,198,086 bp, with 2867 protein-coding sequences; one chromosome and six plasmids were identified. From the genome of SJF2-1, multiple genes homologous to those involved in the conversion of D-glucose to 2,5-DKG were identified. In particular, six different genes encoding membrane-associated flavoprotein-cytochrome c complexed dehydrogenase were identified and divided into two different lineages. This study suggests the potential of G. sphaericus SJF2-1 to mass-produce 2,5-DKG and other D-glucose oxidation products.

Selective oxidation of glucose over transitional metal oxides based magnetic core-shell nanoparticles

Cationic transition metal (Cu and Co) based core-shell (core: magnetite, shell: SiO2, ZrO2 or CeO2) magnetic nanoparticles were investigated in the selective oxidation of D-glucose to gluconic (GLU) and glucuronic (GLUU) acids, working at low temperature, with H2O2 as oxidant and in the absence of any base in the liquid phase. The catalysts have been characterized by FTIR, XRD, NH3- and CO2-TPD and TGA-DTA analyses. Under the optimal reaction conditions (i.e., 40° C and 10 h), the highest conversion of D-glucose was of 86.2 % and the selectivities to GLU and GLUU of 33.8 % and 14.6 %, respectively. These results corresponded to the MSA@Co (were: M – magnetite; S – silica shell, A –APTES) catalyst. This catalyst can be easily recovered by a simple external magnet and reused several consecutive runs, without any change in the catalytic efficiency.

Separation by Size Exclusion: Selective Liquid-Phase Adsorption of l-Lysine from Lysine–Glucose Mixtures on Zeolites

l-Lysine is an essential amino acid of great importance for the pharmaceutical and nutrition industries and is mainly produced by the fermentative conversion of d-glucose. The technological bottleneck for an efficient process is often the development of separation and purification technologies as they can account for 20–50% of the overall operation costs. Liquid-phase adsorption on zeolites is an energy-, resource-, and cost-saving alternative. Zeolites are a well-established and widely available class of adsorbents. In this research, a variety of commercial zeolites of different framework types with varying Si/Al ratios were used to investigate the adsorption of l-lysine from single-component solutions and lysine–glucose mixtures. l-Lysine recovery resulted in adsorption capacities of up to 169 mg g–1 on Hβ-30 in batch experiments. Zeolites showed high l-lysine selectivity in competitive adsorptions from lysine–glucose mixtures, outperforming previously reported adsorbents. Based on the analysis of adsorbent and adsorbate dimensions, a size-exclusion-based separation of l-lysine from d-glucose was proposed, which was found to be primarily responsible for the high l-lysine selectivity. Fourier transform infrared spectroscopy analysis allowed proposing a structure–adsorption relationship for l-lysine on zeolites. The transferability of the batch results to a continuous process was shown. In addition, a high desorption efficiency of up to 90% using water as the desorption solution could be achieved, complemented by successful recyclability tests over five consecutive adsorption–desorption cycles.

Catalytic conversion of d-glucose into lactic acid with Ba(OH)2 as a base catalyst:mechanistic insight by NMR techniques

Lactic acid (2-hydroxypropionic acid, LA) can be produced from abundant and renewable biomass resources via chemocatalytic processes, which exhibited high potential for meeting its tremendous demand in a wide range of applications. The basic Ba(OH)2 could efficiently catalyze the conversion of d-glucose into LA. In the present study, by utilizing various NMR techniques including, chemical shift titration, 2D diffusion ordered spectroscopy (DOSY) analysis, heteronuclear singular quantum correlation (1H–13C HSQC), the binding sites and catalytic interaction between d-glucose and catalyst were clarified. The experimental results by NMR and electrospray ionization mass spectrometry (ESI–MS) were used to explore the reaction mechanism. Experimental results disclosed that the catalyst, Ba(OH)2, may exist in the form of [Ba(OH)(H2O)2]+ under the reaction condition. The OH– of [Ba(OH)(H2O)2]+ is attached to the C5-O of d-glucose, and Ba2+ is connected to the C1-O of d-glucose. Herein, we suppose that Ba(OH)2 and d-glucose interact and form a complex, d-glucopyranose-[Ba(OH)(D2O)2]+. Furthermore, when the reaction was performed in D2O, we were surprised to find that LA underwent varying degrees of deuteration. The reaction mechanism, binding sites and deuteration of the product have shed light on the efficient conversion of biomass to LA.

Catalytic wet air oxidation of d-glucose by perovskite type oxides (Fe, Co, Mn) for the synthesis of value-added chemicals

The conversion of common biomasses derived, as d-glucose, into value-added chemicals has received highest attention in the last few years. Among all processes, the catalytic wet air oxidation (CWAO) of derived biomasses using noble metal-based heterogeneous catalytic systems has been investigated. Nevertheless, the redox effect of such catalysts on such bio-compounds has still to be investigated in detail. In the present work, the activity for the conversion of d-glucose into C6 aldaric acid, lactic acid and levulinic acid of some perovskite type oxides (LaBO3; B: Fe, Co, Mn) characterized by noticeable catalytic properties and stability under hydrothermal conditions, have been investigated. The influence of the reaction temperature and the effect of the catalytic properties on the distribution of the liquid products have been studied. In the best conditions, 50.3 mol.% and 69.5 mol.% of lactic and levulinic acid have been obtained by using LaCoO3 and LaMnO3, respectively. Apart from the oxidative effect, the affinity hydrogen allowed the catalytic conversion of some key intermediates, such as pyruvic aldehyde and hydroxymethylfurfural, into the desired products. LaMnO3, which has resulted to be the most oxidizable/reducible catalyst at low temperatures, has shown the best catalytic activity among the studied catalysts, promoting the conversion of hydroxymethylfurfural to levulinic acid and giving overall the highest yield.

Sulfonic acid-functionalized carbon coated red mud as an efficient catalyst for the direct production of 5-HMF from d-glucose under microwave irradiation

Though suitable for the fructose conversion to 5-hydroxymethylfurfural (5-HMF), sulfonated carbon catalysts are inefficient for the direct glucose transformation to 5-HMF due to the lack of appropriate Lewis acids. Here, we have reported an efficient and inexpensive catalyst by suitably modifying red mud (RM), a by-product from the aluminum industry. The AD-1:1/SO3H catalyst produced by the acid (HCl) treatment, carbon coating, and SO3H grafting on RM exhibited enhanced surface area, mesoporous characteristics, and suitable Lewis and Bronsted acid sites. The XRD, FTIR, and XPS analysis suggested Fe2(SO4)3, Fe2O3, and various carbon functionalities as the major active components in the AD-1:1/SO3H catalyst. The NH3-TPD analysis revealed an appreciable acid site density of 6.8 mmol g−1. Under microwave heating at 180 °C, 30 min, and 90:10 DMSO/water weight percentage ratio, the catalyst produced a d-glucose conversion and 5-HMF yield of 93.05 % and 51.5 %, respectively.

Plasmonic silver nanoparticles promoted sugar conversion to 5-hydroxymethylfurfural over catalysts of immobilised metal ions

Plasmonic photocatalysis has attracted significant attention but not been applied to acid-catalysed reactions. Here we report that visible-light irradiation of silver nanoparticles (AgNPs) significantly promotes Lewis acid-catalysis by several immobilised metal ions to dehydrate sugars, producing 5-hydroxymethylfurfural (HMF) in good yields at moderate temperatures. In one example, we achieved a 68 % yield of HMF for the conversion of d-glucose using immobilised Cr3+ ions and AgNPs under visible-light irradiation. The turnover number achieved in the presence of AgNPs is 13.4 times higher than in the absence of AgNPs. We propose a mechanism whereby sugar molecules coordinate to the metal ions, and light absorption by these metal complexes causes electron density distribution shift to the ions, thereby boosting the catalytic activity. Surface plasmon resonance by the AgNPs amplifies incident light to high intensities, considerably promoting catalytic activity. This plasmon-enhanced acid catalysis performance defines a new paradigm and expands photocatalysis applications.

One-pot enzymatic synthesis of 2-deoxy-scyllo-inosose from d-glucose and polyphosphate.

2-Deoxy-scyllo-inosose (2DOI, [2S,3R,4S,5R]-2,3,4,5-tetrahydroxycyclohexan-1-one) is a biosynthetic intermediate of 2-deoxystreptamine-containing aminoglycoside antibiotics, including butirosin, kanamycin, and neomycin. In producer microorganisms, 2DOI is constructed from d-glucose 6-phosphate (G6P) by 2-deoxy-scyllo-inosose synthase (DOIS) with the oxidized form of nicotinamide adenine dinucleotide (NAD+). 2DOI is also known as a sustainable biomaterial for production of aromatic compounds and a chiral cyclohexane synthon. In this study, a one-pot enzymatic synthesis of 2DOI from d-glucose and polyphosphate was investigated. First, 3 polyphosphate glucokinases (PPGKs) were examined to produce G6P from d-glucose and polyphosphate. A PPGK derived from Corynebacterium glutamicum (cgPPGK) was found to be suitable for G6P production under ordinary enzymatic conditions. Next, 7 DOISs were examined for the one-pot enzymatic reaction. As a result, cgPPGK and BtrC, the latter of which is a DOIS derived from the butirosin producer Bacillus circulans, achieved nearly full conversion of d-glucose to 2DOI in the presence of polyphosphate.

Определение термодинамических характеристик реакции получения N-метил-D-глюкозимина

The presented article is devoted to thermodynamic calculations of the N-methyl-D-glucosimine reversible formation reaction, an intermediate product for N-methyl-D-glucosamine synthesis, which is widely used in pharmaceutical practice as a ballast or counterion that improves the bioavailability of the main active substance. N-methyl-D-glucosimine is synthesized as a result of the interaction of D-glucose with methylamine in organic solvents, the reaction is reversible, and the yield of the target product depends entirely on the reaction conditions. The use of thermodynamic calculations makes it possible to evaluate the influence of the chemical process conditions on the yield of target products, which in turn contributes to a deeper understanding of the chemical reactions mechanisms. In chemical equilibrium, direct and reverse reactions proceed at equal rates, while the concentrations of products and reagents remain constant. When the reaction proceeds in a closed system, after a certain time, a state of equilibrium occurs, while the reaction does not proceed with a complete transformation of the reagents. This article presents the results of thermodynamic calculations of the reaction for the synthesis of N-methyl-D-glucosimine by the Van Kravlen – Cheremnov method. The Gibbs energy, equilibrium constants, and D-glucose conversion were calculated as activity function of reacting substances. It was shown that an increase in the temperature of the reaction mixture from 20 to 160 °C promotes an increase in the conversion of D-glucose from 3 to 32%, and therefore it is possible to recommend carrying out this reaction at elevated temperatures.

A Novel Glucose Isomerase from Caldicellulosiruptor bescii with Great Potentials in the Production of High-Fructose Corn Syrup.

Glucose isomerase (GI) that catalyzes the conversion of D-glucose to D-fructose is one of the most important industrial enzymes for the production of high-fructose corn syrup (HFCS). In this study, a novel GI (CbGI) was cloned from Caldicellulosiruptor bescii and expressed in Escherichia coli. The purified recombinant CbGI (rCbGI) showed neutral and thermophilic properties. It had optimal activities at pH 7.0 and 80°C and retained stability at 85°C. In comparison with other reported GIs, rCbGI exhibited higher substrate affinity (Km = 42.61 mM) and greater conversion efficiency (up to 57.3% with 3M D-glucose as the substrate). The high catalytic efficiency and affinity of this CbGI is much valuable for the cost-effective production of HFCS.

Rational Design of Metal Oxide Solid Acids for Sugar Conversion

Aqueous-phase acid-catalyzed reactions are essential for the conversion of cellulose-based biomass into chemicals. Brønsted acid and Lewis acid play important roles for these reactions, including hydrolysis of saccharides, isomerization and epimerization of aldoses, conversion of d-glucose into 5-hydroxymethylfurfural, cyclodehydration of sugar alcohols and conversion of trioses into lactic acid. A variety of metal oxide solid acids has been developed and applied for the conversion of sugars so far. The catalytic activity is mainly dependent on the structures and types of solid acids. Amorphous metal oxides possess coordinatively unsaturated metal sites that function as Lewis acid sites while some crystal metal oxides have strong Brønsted acid sites. This review introduces several types of metal oxide solid acids, such as layered metal oxides, metal oxide nanosheet aggregates, mesoporous metal oxides, amorphous metal oxides and supported metal oxides for sugar conversions.

Improving conversion of d-Glucose into short-chain alkanes over Ru/MCM-48 based catalysts

Abstract The production of fuels from biomass is a key factor for sustainability. With this aim, we have studied the conversion of d -Glucose into short-chain alkanes in a one-pot biphasic catalytic system, evaluating different modifications of Ru/MCM-48: Ru/Al-MCM-48 and Ru/MCM-48 with the addition of tungstophosphoric acid, and compared with a commercial Ru/C. Additionally, different combinations of the previous were studied. Catalysts were characterized in terms of X-ray Diffraction/Small Angle X-Ray Scattering, N2 adsorption/desorption, Temperature Programmed Reduction with H2, Temperature Programmed Desorption of Ammonia, Transmission Electron Microscopy and Atomic Absorption. The reaction was carried out at 190 °C under 5 MPa of H2 in a biphasic n-decane–water system. In the absence of tungstophosphoric acid, the reaction took place through a first hydrogenation to sorbitol followed by dehydration and hydrodeoxigenation. In this terms, the presence of Al-MCM-48 showed to play a very important role in the production of light alkanes, favoring the dehydration step. The reverse trend was observed in the presence of tungstophosphoric acid. In this case, the reaction occurred first by the dehydration of glucose, followed by hydrogenation and hydrodeoxigenation. Here, once the dehydration had been promoted by tungstophosphoric acid, the following hydrogenation step was favored on Ru/C, which is preferentially located in the organic phase. The global results, in terms of alkane formation, shows how the presence of Al-MCM-48 conducts to promising results, outperforming commercial or other literature reported systems.

Synthesis of ertugliflozin from d-glucose

A new synthesis of ertugliflozin from d-glucose in 7% overall yield is reported. The reaction sequence involves conversion of d-glucose to a fully protected open chain d-glucose aldehyde in 4 steps, further installation of the aglycon group by a Grignard reaction, introduction of the hydroxymethyl group by a sequential oxidation/aldol reaction/Canizzarro reduction, and finally benzylic oxidation and global deprotection.

Conversion of d-glucose to l-lactate via pyruvate by an optimized cell-free enzymatic biosystem containing minimized reactions

Cell-free synthetic enzymatic biosystem is emerging to expand the traditional biotechnological mode by utilizing a number of purified/partially purified enzymes and coenzymes in a single reaction vessel for the production of desired products from low-cost substrates. Here, a cell-free synthetic biosystem containing minimized number of reactions was designed for the conversion of d-glucose to l-lactate via pyruvate. This NADH-balanced biosystem was comprised of only 5 thermophilic enzymes without ATP supplementation. After optimization of enzyme loading amounts, buffer concentration and cofactor concentration, d-glucose was converted to l-lactate with a product yield of ∼90%. Our study has provided an emerging platform with potentials in producing pyruvate-derived chemicals, and may promote the development of cell-free synthetic enzymatic biosystems for biomanufacturing.

Estrogenicity of Octyl Glucoside Synthesized by Direct Glucosidation as Non-Endocrine Disruptive Surfactant.

The estrogenicity of octyl glucoside was studied with its preparation method using microporous zeolites. Its estrogenicity was estimated using E-assay method to confirm the possibility as non-endocrine disruptive surfactant. The octyl glucoside was synthesized from D-glucose with 1-octanol by direct glucosidation. The high conversion of D-glucose was obtained on H-FAU zeolite which has a mild acid strength. The conversion and yield were improved with increasing of acid site amount of the zeolite catalysts. The octyl glucopyranoside is more hydrophilic than nonylphenol and has a high wettability. The octyl glucosides represented extremely lower estrogenic cell proliferation compared with nonylphenol.