Glucaric Acid Research Articles

Comprehensive Analysis of Phenolic Compounds in Solanum glaucophyllum Desf.

Solanum glaucophyllum Desf. (SG) has been well studied due to the presence of 1,25(OH)2D3 glycosides, but little is known about the composition and presence of other phenolic glycosides that are also part of the plant's composition. In fact, only 8 phenolic ingredients have been described in the literature; thus, the current study aimed to comprehensively extend the phenolic composition. Aqueous leaf extracts were separated by reversed-phase chromatography or, after permethylation, on normal phase chromatography. Two novel quercetin derivatives were isolated, including 7-O-β-glucosyl-α-apiosyl rutin, which was never reported in the literature before. In total, five quercetin glycosides containing one to four sugar units were determined quantitatively for the first time in SG, reaching a total 4.16% dry matter. Additionally, arbutin and 27 cinnamoyl derivatives were identified and quantitated via LC-MS/MS, totaling 0.57% and 2.15% dry matter of leaves, respectively. The quantitative results were based on independent syntheses of 1-O-and 3-O-caffeoyl- and 3-O-feruloyl glucoside, isolation of 3/4-O-caffeoyl- and 3/4-O-p-coumaroyl glucaric acid from SG leaves, and the use of authentic reference material (3- and 5-O-cinnamoyl quinic acids). All of the isolated and synthesized substances were unequivocally verified by HR-MS and NMR spectroscopy.

A metabolic-engineering framework approach via fed-batch fermentation for enhancing glucaric acid production in Komagataella phaffii.

A metabolic-engineering framework approach via fed-batch fermentation for enhancing glucaric acid production in Komagataella phaffii.

Copper(II) complexes of 2-hydroxy-1-naphthaldehyde Schiff bases: synthesis, in vitro activity and computational studies.

Due to the divers biological applications of Cu(II) complexes, we in this study reports the various Cu(II) complexes. The study aims to synthesize and assess new Cu(II) complexes as powerful β-glucuronidase inhibitors. Five Schiff base ligands and their complexes were synthesized, characterized, and screened against β-glucuronidase inhibitory activity. In the series, compounds 3e, 3c, 2b, and 2c ascribed powerful inhibition ranging from (IC50 = 3.0 ± 0.7 µM) to (IC50 = 19.2 ± 0.8 µM). A precise and particular arrangement of atoms is suggested by the triclinic p-1 space group and the existence of a single molecule in an asymmetric unit, which are indispensable for the reactivity as well as the stability of the compounds. The analysis of the Hirshfeld surface provides information about the hydrogen intermolecular and π-π interactions. Based on molecular docking, binding potency increasing by complexation 3a-e compared to ligands 2a-e as well as reference Saccharic acid and uronic isofagomine inhibitor, suggesting that it may be a potent inhibitor of these receptors. The work recognizes latent active compounds for novel β-glucoronidase inhibitors, by further support these may be harnessed for the development of potent drugs.

4-O-Methylglucaric Acid Production from Xylan with Uronic Acid Oxidase and Comparison to Glucaric Acid from Glucose.

This study describes an enzymatic pathway to produce high purity 4-O-methylglucaric acid from xylan, an underutilized fraction of lignocellulosic biomass. Beechwood xylan was enzymatically hydrolysed using a commercial xylanase and an α-glucuronidase from Amphibacillus xylanus to form 4-O-methylglucuronic acid, which was then purified by anion exchange chromatography and subsequently oxidized to 4-O-methylglucaric acid using a recombinantly produced uronic acid oxidase from Citrus sinensis. Enzymatic oxidation with uronic acid oxidase afforded 95 % yield in 72 hours which is considerably higher than yields previously achieved using a glucooligosaccharide oxidase from Sarocladium strictum. 4-O-methylglucaric acid was isolated by precipitation and purified by recrystallization. Characterization by liquid chromatography mass spectrometry and nuclear magnetic resonance spectroscopy confirmed product identity and high purity (97.8 % w/w). 4-O-methylglucaric acid's performance as a detergent builder was compared to commercial glucaric acid. At 10 : 1 molar ratios of detergent builder to calcium, 4-O-methylglucaric acid provided similar calcium sequestration performance to glucaric acid (less than 5 % difference) at pH 7 and pH 10 in the presence of surfactants, including sodium dodecylbenzene sulfonate. Given their similar calcium sequestration performance, 4-O-methylglucaric acid could effectively substitute for glucaric acid in detergent formulations.

"Suspended" Single Rhenium Atoms on Nickel Oxide for Efficient Electrochemical Oxidation of Glucose.

Well-defined single-atom catalysts (SACs) serve as ideal model systems for directly comparing experimental results with theoretical calculations, offering profound insights into heterogeneous catalytic processes. However, precisely designing and controllably synthesizing SACs remain challenging due to the unpredictable structure evolution of active sites and generation of embedded active sites, which may bring about steric hindrance during chemical reactions. Herein, we present the precious nonpyrolysis synthesis of Re SACs with a well-defined phenanthroline coordination supported by NiO (Re1-phen/NiO). Multiple experimental characterizations together with theoretical calculations unravel the idea that the isolated Re atoms are suspended on the NiO surface, connected by phenanthroline ligands standing perpendicular to the surface. This unique structure provides the Re1-phen/NiO SAC with a strong capability to activate glucose molecules, enabling fully exposed Re=O double bonds in an open-ended reaction environment to simultaneously react with hydroxyl and aldehyde groups at both ends of the glucose molecule, rapidly forming glucaric acid.

Selective photocatalytic glucaric acid production from TEMPO-mediated glucose oxidation on alkalized carbon nitride

Selective photocatalytic glucaric acid production from TEMPO-mediated glucose oxidation on alkalized carbon nitride

Valorization of Legume By-Products Based on Polyphenols and Protein Contents for Potential Nutraceutical Applications.

A significant amount of agri-food by-products is generated by large food industry production lines. Aligned with the principles of a circular economy, this project aims to recycle and valorize legumes, such as beans, green beans and soy by-products characterized by different heat treatments, maturation stages and cultivation methods. The valorization of food waste involved the development of an Ultrasound-Assisted Extraction (UAE) method to isolate polyphenols. Analytical techniques, including UHPLC-DAD-ESI-MSn, were used to identify polyphenols in legume, green bean and soy extracts obtained through UAE. Additionally, UV-Vis spectrophotometric assays measured the Total Phenolic Content (TPC) and Total Antioxidant Status (TAS), while the Kjeldahl method was employed to assess the protein content in each UAE extract. The analyses revealed a variety of valuable polyphenols in legume, green bean and soy by-products. For instance, bean by-products contain feruloyl glucaric acid derivatives, green beans by-products have different types of flavonols such as quercetin-3-O-glucuronide, and soy by-products are rich in isoflavones. These findings demonstrate the potential for formulating nutraceuticals from these by-products' extracts.

Sustainable catalytic pathways for biofuel precursors: quantitative conversion of glucose to gluconic acid using Pt-Zn biochar catalyst

Achieving quantitative conversion of biomass-derived feedstocks under ambient environmental conditions (20°C, atmospheric air, 0.1 MPa) is a critical milestone for sustainability in chemical processes. Herein, the quantitative conversion of glucose to gluconic acid was accomplished under ambient environmental conditions without any additives using a Pt-Zn intermetallic nanoparticle-supported biochar catalyst prepared from raw rice straw (Pt-Zn/strawC) via a straightforward one-pot solvothermal reaction with ethylene glycol solvent. Spectroscopic analyses verified the formation of the Pt-Zn intermetallic alloy and confirmed strong electronic metal-support interactions. The Pt-Zn/strawC catalyst (Pt:Zn molar ratio of 1:6) was highly selective for the conversion of glucose to gluconic acid, whereas yields as high as 99.9% (98.9% gluconic acid, 1.0% glucaric acid) were reached at 20 oC under base-free and additive-free conditions. Isotope measurements and density functional theory revealed synergistic interactions in the Pt-Zn alloy, wherein the alloy tended to absorb glucose and active O2 into superoxide radical (O2·). This work demonstrates a chemocatalytic method that is practical for environmental conditions and provides a new avenue for sustainable conversion of lignocellulosic biomass to chemical products.

Exploration of potential biomarkers for prurigo nodularis based on plasma-metabolome analysis.

Prurigo nodularis (PN) is a chronic and debilitating skin disease with severe itching that negatively impacts patients' quality of life and mental state. However, the treatment options for PN remain limited. Global metabolomics analysis can offer effective information on energy metabolism, pathogenesis and potential diagnostic biomarkers. No study on metabolomic analysis of PN has been reported. To further understand the mechanisms of PN and analyse the plasma metabolite profiles in patients with PN. Targeted-metabolome analysis of 306 metabolites in plasma from 18 patients with PN and 19 healthy controls was performed using Liquid Chromatography-tandem Mass Spectrometer analysis. We identified 31 differential metabolites. Most acylcarnitines, long-chain fatty acids, alpha-aminobutyric acid, hydroxybutyric acid and lactic acid among these metabolites were up-regulated in patients with PN; in contrast, glucaric acid, suberic acid, bile acid derivatives and most amino acids were down-regulated. Positive correlations exist between glucaric acid and itching severity and acylcarnitines and insomnia. Suberic acid and the Investigator's Global Assessment (IGA) scores correlate negatively. Metabolite variation reflects the dysregulation of energy metabolism and chronic systematic inflammation in PN. Several metabolites, such as glucaric acid, suberic acid and acylcarnitines, merit further study as potential biomarkers of disease severity in PN.

Decoding comparative taste and nutrition regulation in Chinese cabbage via integrated metabolome and transcriptome analysis

Chinese cabbage (Brassica rapa L. ssp. pekinensis) is a widely consumed leafy vegetable known for its various health-beneficial nutrients. Caixin (ET and JY) represent distinct cultivars of Chinese cabbage that exhibit differential consumer preference attributed to variations in taste and nutritional content, with ET being characterized as sweeter and more nutritionally superior compared to JY. However, limited research has been conducted to explore regulation of flavor and nutrition-related quality traits in Chinese cabbage. In this pioneer study, comprehensive trans-meta-analysis was used to compare the metabolic and molecular underpinnings behind unique taste and nutritional profiles of ET and JY. 8-Methylsulfonyloctyl glucosinolates and Uridine 5′-diphospho-D-glucose exhibited the highest correlation coefficient in Pearson meta–meta-association, which modulate flavor and nutrition processes. While DAMs primarily featured L-Homomethionine, saccharic acid, 1,6-Di-O-caffeoyl-β-D-glucose, and Rutin, with notable variations in expression between ET and JY. Conspicuously, DEGs encoding structural enzymes i.e. Glucosinolates (MAM, CYP, UGT), flavonoids (CHS, CHI, F3H) and sucrose (SPS, SPP, SUS) synthases were identified as key players in nutrient and flavor production. Multi-omics conjoint analysis revealed that saccharides, amino acids, ascorbates, flavonoids, organic acids and vitamins were positively correlated with taste and nutrition, and were found to be overexpressed in ET. While aliphatic glucosinolates were abundant in JY compared to ET, they might play a critical role in regulating quality traits. Besides, HPLC and RT-qPCR corroborated multi-omics data reliability. These findings offer novel insights into the mechanisms governing the regulation of taste and nutritional levels in Chinese cabbage.

New advances in protein engineering for industrial applications: Key takeaways.

Recent advancements in protein/enzyme engineering have enabled the production of a diverse array of high-value compounds in microbial systems with the potential for industrial applications. The goal of this review is to articulate some of the most recent protein engineering advances in bacteria, yeast, and other microbial systems to produce valuable substances. These high-value substances include α-farnesene, vitamin B12, fumaric acid, linalool, glucaric acid, carminic acid, mycosporine-like amino acids, patchoulol, orcinol glucoside, d-lactic acid, keratinase, α-glucanotransferases, β-glucosidase, seleno-methylselenocysteine, fatty acids, high-efficiency β-glucosidase enzymes, cellulase, β-carotene, physcion, and glucoamylase. Additionally, recent advances in enzyme engineering for enhancing thermostability will be discussed. These findings have the potential to revolutionize various industries, including biotechnology, food, pharmaceuticals, and biofuels.

Ultrasonication‐Assisted Preparation of Au‐Pt/ZrO2 Catalysts for the Selective Base‐Free Oxidation of Glucose to Glucaric Acid

AbstractSelective catalytic oxidation of glucose to glucaric acid is still challenging due to the potential formation of a large range of by‐products. ZrO2 supported AuPt catalysts are very efficient for this reaction under base‐free conditions, in aqueous phase. Different preparation methods were tested and the catalysts synthesized by co‐impregnation using NaBH4 as reductant gave the most promising results. We demonstrated that the presence of a pure AuPt alloy is critical for the selective formation of glucaric acid. We have shown that when ultrasonication was used during preparation, less by‐products were formed, increasing significantly final yield of glucaric acid, up to 71 %. The Au/Pt ratio affects the catalytic results and an optimal ratio around 1.1 was determined. Finally, the catalyst is stable up to 196 h in continuous reactor.

Enhancing glucaric acid production from myo-inositol in Escherichia coli by eliminating cell-to-cell variation.

Glucaric acid (GA) is a value-added chemical and can be used to manufacture food additives, anticancer drugs, and polymers. The non-genetic cell-to-cell variations in GA biosynthesis are naturally inherent, indicating the presence of both high- and low-performance cells in culture. Low-performance cells can lead to nutrient waste and inefficient production. Furthermore, myo-inositol oxygenase (MIOX) is a key rate-limiting enzyme with the problem of low stability and activity in GA production. Therefore, eliminating cell-to-cell variations and increasing MIOX stability can select high-performance cells and improve GA production. In this study, an in vivo GA bioselector was constructed based on GA biosensor and tetracycline efflux pump protein TetA to continuously select GA-efficient production strains. Additionally, the upper limit of the GA biosensor was improved to 40 g/L based on ribosome-binding site optimization, achieving efficient enrichment of GA high-performance cells. A small ubiquitin-like modifier (SUMO) enhanced MIOX stability and activity. Overall, we used the GA bioselector and SUMO-MIOX fusion in fed-batch GA production and achieved a 5.52-g/L titer in Escherichia coli, which was 17-fold higher than that of the original strain.IMPORTANCEGlucaric acid is a non-toxic valuable product that was mainly synthesized by chemical methods. Due to the problems of non-selectivity, inefficiency, and environmental pollution, GA biosynthesis has attracted significant attention. The non-genetic cell-to-cell variations and MIOX stability were both critical factors for GA production. In addition, the high detection limit of the GA biosensor was a key condition for performing high-throughput screening of GA-efficient production strains. To increase GA titer, this work eliminated the cell-to-cell variations by GA bioselector constructed based on GA biosensor and TetA, and improved the stability and activity of MIOX in the GA biosynthetic pathway through fusing the SUMO to MIOX. Finally, these approaches improved the GA production by 17-fold to 5.52 g/L at 65 h. This study represents a significant step toward the industrial application of GA biosynthetic pathways in E. coli.

Production of H2 and Glucaric Acid Using Electrocatalyst Glucose Oxidation by the Ta NiFe LDH Electrode.

The slow anodic oxygen evolution reaction (OER) significantly limits electrocatalytic water splitting for hydrogen production. We proposed the electrocatalyst for glucose oxidation by Ta-doping NiFe LDH nanosheets to simultaneously obtain glucaric acid (GRA) and hydrogen gas as a useful byproduct. Superior glucose oxidation reaction (GOR) activity is demonstrated by the optimized Ta-NiFe LDH, which has a low overpotential of 192 mV, allowing for a small Tafel slope of 70 mV dec-1 and a current density of 50 mA cm-2. The Ta NiFe LDH-oxidized glucose to GRA with a 72.94% yield and 64.3% Faradaic efficiency at 1.45 VRHE. Herein, we report the Ta NiFe LDH/NF electrode for the GOR&hydrogen evolution reaction (HER), which exhibits a cell voltage of 1.62 V to reach a current density of 10 mA cm-2, which is 250 mV lower compared to OER&HER (1.87 V). This study reveals that GOR is an energy-efficient and cost-effective method for producing H2 and valorizing biomass.

Selective glucose electro-oxidation catalyzed by TEMPO on graphite felt.

Long-term electrolyses of glucose in a potassium carbonate (K2CO3) aqueous electrolyte have been performed on graphite felt electrodes with TEMPO as a homogeneous catalyst. The influences of the operating conditions (initial concentrations of glucose, TEMPO, and K2CO3 along with applied anode potential) on the conversion, selectivity toward gluconate/glucarate, and faradaic efficiency were assessed first. Then, optimizations of the conversion, selectivity, and faradaic efficiency were performed using design of experiments based on the L9 (34) Taguchi table, which resulted in 84% selectivity toward gluconate with 71% faradaic efficiency for up to 79% glucose conversion. Side products such as glucaric acid were also obtained when the applied potential exceeded 1.5V vs. reversible hydrogen electrode.

Calcium saccharate/DUSP6 suppresses renal cell carcinoma glycolytic metabolism and boosts sunitinib efficacy via the ERK-AKT pathway

Calcium saccharate/DUSP6 suppresses renal cell carcinoma glycolytic metabolism and boosts sunitinib efficacy via the ERK-AKT pathway

Liquid chromatography–mass spectrometry and xCELLigence real time cell analyzer revealed anticancer and antioxidant metabolites in Trianthema portulacastrum L. (Aizoaceae)

BackgroundThe rising incidence of cancer is a major concern globally being a leading cause of early mortality in most countries. This burden is projected to increase to 28.4 million cases worldwide by 2040 and yet, may be worsened by continuous exposure to risk factors due to a sheer shift from consumption of natural nutrients. To reverse this trend, it is imperative to source novel anticancer metabolites from plants that could minimize carcinogenic effects by suppressing the proliferation and survival of cancer cells. PurposeThis study aimed at characterizing and quantifying index anticancer and antioxidant metabolites, in the cultivars of T. portulacastrum. MethodsThe Ultra-High Performance Liquid Chromatography Mass Spectroscopy (UHP-LCMS) was used to quantify and characterize index anticancer and antioxidant metabolites in shoot, root and whole plant extracts of Trianthema portulacastrum (T01,T02,T03,T04,T05,T06). The biological activity of the tested samples was monitored on the xCELLigence Real Time Cell Analyzer to determine the cytotoxicity of the extracts as a function of cell index at a specific time post dose using the concentration range of 0.16–2.5 %. ResultsBased on the responses observed 48 h post exposure, all extracts showed high levels of cytotoxicity as determined by the xCELLigence apart from the root extracts. Rapid decreases in cell index (CI) values observed at higher extract percentages are highly indicative of cell death. These biological activities may be attributed to different anticancer metabolites such as epigallocatechin, glucaric acids, byakangelicin, xanthotoxin, apaensin, acetoxy-6-gingerol among other compounds of significant therapeutic benefits that were quantified with UHP-LCMS. ConclusionThese findings suggest that T. portulacastrum contains diverse anticancer metabolites which could be leveraged to develop plant-based anticancer drugs or novel chemicals with extended therapeutic utility.

Cation-mediated acid-base pairs for mild oxidative cleavage of lignocellulosic β-1,4-glycosidic bonds

Solar-driven lignocellulosic biomass photoreforming holds significant promise for the production of value-added chemicals and fuels. The cleavage of the β-1,4-glycosidic bond is crucial for the effective conversion of lignocellulosic biomass. Polymeric carbon nitride (PCN) with acid-base pairs (M-C sites) is developed through heteroatomic carbon incorporation and cation insertion. It can be used for the gentle oxidation of cellobiose to monosaccharides, bypassing the formation of organic acids such as gluconic acid and glucaric acid. A series of different alkaline/alkaline-earth cation for regulation of acid-base pairs exhibited a negative correlation between β-1,4-glycosidic bond cleavage and cation radii. In particular, the introduction of short-radius cations (such as Li) into PCN enabled the formation of acid-base (M-C) pairs characterized by strong acidity. It also enhanced electron delocalization around M-C sites, potentially promoting the generation of reactive radicals in the reaction. Electron paramagnetic resonance analysis confirmed the presence of •OH radicals. The mild oxidative species, are the primary reactive radicals responsible for β-1,4-glycosidic bond cleavage in cellobiose. This study provides insightful evidence for the rational regulation of acid-base sites in facilitating β-1,4-glycosidic bond cleavage. It sheds light on the oxidative cleavage mechanisms integral to lignocellulosic biomass photoreforming, offering insights for advancing sustainable biomass conversion technologies.

Glucaric Acid Production from Miscanthus sacchariflorus via TEMPO-Mediated Oxidation with an Efficient Separation System.

In this study, production and isolation of glucaric acid from lignocellulosic biomass were performed via potassium cation-based TEMPO-mediated oxidation for the ease of glucaric acid isolation. To optimize the oxidation conditions, response surface methodology (RSM) was adopted using standard glucose as the raw material. Among the oxidation conditions, the dosage of oxidant and pH of reaction affected the glucaric acid production, and the optimum conditions were suggested by RSM analysis: 5 °C of reaction temperature, 4.23 equiv dosage of KClO per mole of glucose, and pH of 12. Furthermore, glucaric acid was produced from lignocellulosic biomass-derived enzymatic hydrolysate from Miscanthus under optimum conditions. The impurities such as xylose and lignin in enzymatic hydrolysate inhibited the efficiency of glucose oxidation. As a result, more oxidant was required to produce sufficient glucaric acid from the enzymatic hydrolysate compared to standard glucose. The produced glucaric acid was simply isolated by controlling the pH in the form of glucaric acid monopotassium salt, which showed lower solubility in water, and the purity of isolated glucaric acid was over 99%. The overall mass balance of feedstock to glucaric acid was analyzed, suggesting that 86.38% (w/w) glucaric acid could be produced from initial glucan in feedstock.

Ultralow RuO2 Doped NiS2 Heterojunction as a Multifunctional Electrocatalyst for Hydrogen Evolution linking to Biomass Organics Oxidation.

Hydrogen energy and biomass energy are green and sustainable forms that can solve the energy crisis all over the world. Electrocatalytic water splitting is a marvelous way to produce hydrogen and biomass platform molecules can be added into the electrolyte to reduce the overpotential and meanwhile are converted into some useful organics, but the key point is the design of electrocatalyst. Herein, ultralow noble metal Ru is doped into NiS2 to form RuO2@NiS2 heterojunction. Amongst them, the 0.06 RuO2@NiS2 has low overpotentials of 363mV for OER and 71mV for HER in 1m KOH, which are superior to the RuO2 and Pt/C. Besides, the 0.06 RuO2@NiS2 shows a low overpotential of 173mV in 1m KOH+0.1m glycerol, and the glycerol is oxidized to glyceraldehyde and formic acid via the high Faraday efficiency GlyOR process, and the splitting voltage is only 1.17V. In addition, the 0.06 RuO2@NiS2 has a low overpotential of 206mV in 1m KOH+0.1m glucose, and the glucose is converted to glucaric acid, lactic acid, and formic acid. This work has a "one stone three birds" effect for the production of hydrogen, low splitting voltage, and high-value-added biomass chemicals.