Fumarate Research Articles

Separation of Fumaric and Maleic Acid Crystals from the Industrial Wastewater of Maleic Anhydride Production

In this research, a physicochemical analysis of the industrial wastewater from a factory that produces maleic anhydride was performed. Based on the conducted analysis (pH, electrical conductivity, density of the liquid phase, boiling point of the waste suspension, chemical as well as biological oxygen demand, and dry matter), it can be concluded that the waste stream obtained at the outlet pipe from the plant resulting from the production of maleic anhydride requires appropriate treatments. Some of the parameters measured, e.g. pH (0.97±0.06), boiling point (106.8±1.3°C) and acidity, indicate the presence of organic acids such as fumaric and maleic acids, which are formed during the production of maleic anhydride. The possibility of extracting crystals by adding urea and thiourea followed by forced cooling in a heat exchanger was investigated. The most effective method was the addition of thiourea when the most significant amount of crystals was obtained, namely 17.29 wt%. The addition of thiourea in combination with forced cooling greatly facilitates the process of separating the solid and liquid phases of the waste suspension, which could later be adequately treated by physical, chemical or biological methods.

Comprehensive evaluation of novel fungicide benzovindiflupyr at the enantiomeric level: Bioactivity, toxicity, mechanism, and dissipation behavior

Racemates in the environment can lead to inaccurate risk assessment. To obtain the enantiomeric level information of benzovindiflupyr for accurate risk assessment, the absolute configuration of benzovindiflupyr was first confirmed, and the enantioseparation method was developed by supercritical fluid chromatography tandem mass spectrometry. The enantioselectivity for bioactivity and toxicity was investigated, and the mechanism was explored by molecular docking and detecting succinate dehydrogenase (SDH) activity and content of succinate acid. 1S,4R-(−)-benzovindiflupyr was identified as the most active against the six targeted phytopathogens, which showed higher 1.7–54.5 times than 1R,4S-(+)-benzovindiflupyr. Additionally, 1S,4R-(−)-benzovindiflupyr (LD50: 21.54 μg L−1) was 103.7 times more toxic than 1R,4S-(+)-benzovindiflupyr against Daphnia magna. 1S,4R-(−)-benzovindiflupyr had a stronger affinity for SDH and significantly inhibited SDH activity, resulting in an increase in succinate acid in the tricarboxylic acid cycle, while its downstream products, fumaric and L-malic acid were significantly reduced. Moreover, the dissipation behavior of benzovindiflupyr on three vegetables was evaluated. 1S,4R-(−)-benzovindiflupyr was preferentially degraded in tomato, but opposite in leaves. The enantioselectivity in pepper and cucumber leaves was the same as in tomato, while there was no enantioselectivity in pepper and cucumber. The study provides a basis for accurate risk assessment and the development of high-effective and low-risk fungicides.

Effects of black soldier fly larvae as protein or fat sources on apparent nutrient digestibility, fecal microbiota, and metabolic profiles in beagle dogs.

Black soldier fly (Hermetia illucens) larvae (BSFL) act as a biological system converting organic waste into protein and fat with great potential application as pet food. To evaluate the feasibility of BSFL as a protein and fat source, 20 healthy beagle dogs were fed three dietary treatments for 65 days, including (1) a basal diet group (CON group), (2) a basal diet that replaced 20% chicken meal with defatted black soldier fly larvae protein group (DBP group), and (3) a basal diet that replaced 8% mixed oil with black soldier fly larvae fat group (BF group). This study demonstrated that the serum biochemical parameters among the three groups were within the normal range. No difference (p > 0.05) was observed in body weight, body condition score, or antioxidant capacity among the three groups. The mean IFN-γ level in the BF group was lower than that in the CON group, but there was no significant difference (p > 0.05). Compared with the CON group, the DBP group had decreasing (p < 0.05) apparent crude protein and organic matter digestibility. Furthermore, the DBP group had decreasing (p < 0.05) fecal propionate, butyrate, total short-chain fatty acids (SCFAs), isobutyrate, isovalerate, and total branched-chain fatty acids (BCFAs) and increased (p < 0.05) fecal pH. Nevertheless, there was no difference (p > 0.05) in SCFAs or BCFAs between the CON and BF groups. The fecal microbiota revealed that Lachnoclostridium, Clostridioides, Blautia, and Enterococcus were significantly enriched in the DBP group, and Terrisporobacter and Ralstonia were significantly enriched in the BF group. The fecal metabolome showed that the DBP group significantly influenced 18 metabolic pathways. Integrating biological and statistical correlation analysis on differential fecal microbiota and metabolites between the CON and DBP groups found that Lachnoclostridium, Clostridioides, and Enterococcus were positively associated with biotin. In addition, Lachnoclostridium, Clostridioides, Blautia, and Enterococcus were positively associated with niacinamide, phenylalanine acid, fumaric acid, and citrulline and negatively associated with cadavrine, putrescine, saccharopine, and butyrate. In all, 20% DBP restrained the apparent CP and OM digestibility, thereby affecting hindgut microbial metabolism. In contrast, 8% BF in the dog diet showed no adverse effects on body condition, apparent nutrient digestibility, fecal microbiota, or metabolic profiles. Our findings are conducive to opening a new avenue for the exploitation of DBP and BF as protein and fat resources in dog food.

A comparative study of the effect of bacteria and yeasts communities on inoculated and spontaneously fermented apple cider

Understanding bacteria and yeasts communities can reduce unpredictable changes of apple cider. In this study, apple juice inoculated with Saccharomyces cerevisiae WET 136 and fermented spontaneously were compared, the relationships of bacteria, yeasts, organic acids, and volatiles were analyzed. Results showed that microbial diversity affected the fermentation, organic acids and volatiles in apple ciders. In the first four spontaneous fermentation days, LAB (lactic acid bacteria) multiplied and reached 7.89 lg CFU/mL, and then triggered malolactic fermentation (MLF), leading to malic acid decreased by 3880.52 mg/L and lactic acid increased by 4787.55 mg/L. The citric, succinic and fumaric acids content was 2171.14, 701.51 and 8.06 mg/L lower than that in inoculated cider, respectively. Although the yeasts multiplied during spontaneous fermentation, it did not reach 7.50 lg CFU/mL until the 5th day, which led to a long lag period, as well as later and lower production of acetaldehyde and higher alcohols. The inoculated yeast inhibited LAB, acetic acid bacteria, Rahnella, and non-Saccharomyces. Yeasts were the key to produce citric acid, acetaldehyde and 3-methyl-1-butanol in apple cider; while bacteria were closely related to the formation of lactic acid, acetic acid and ethyl acetate. It suggested that low higher alcohols and acetaldehyde can be realized by selecting yeasts, and Leuconostoc pseudomesenteroides can work as candidate to reduce L-malic and citric acids in apple cider.

Solubility study and thermodynamic modelling of succinic acid and fumaric acid in bio-based solvents

The solubility and involved energies of organic acids in green solvents are relevant to the design of sustainable biorefinery downstream processes. In this work, the solubility of two important bio-based organic acids such as succinic acid and fumaric acid, in water and four bio-based solvents (i.e., ethyl acetate, 1,8-cineole, cyclopentyl methyl ether, and 2-methyl tetrahydrofuran) were measured within a temperature range of [283 – 313] K. A gravimetric methodology was adopted, previously validated using the organic acid aqueous solubilities available in the literature. The reported data present an average estimated uncertainty of measurement, with a level of confidence of 95%, of 5.2·10-4 mol·mol−1. Experimental results were correlated with the van’t Hoff equation, and the Buchowski–Ksiazaczak λh model, where the root mean squared deviations were <3.9·10-4 for all systems. From the experimental data and the COSMO-RS molecular simulation method, the solid–liquid equilibria were modelled to estimate the excess energies and the solute activity coefficients of the saturated solutions. Excess enthalpy contribution analysis shows that attractive hydrogen-bonding interactions between the organic acids and the green solvents drive the dissolution phenomena. The magnitude of the hydrogen-bonding interactions increases with temperature for all systems, agreeing with the observed solubility trends. The organic acid energies of solution were estimated from the van’t Hoff equation, demonstrating an enthalpy–entropy compensation effect. The energetic analysis shows that the dissolution phenomenon is an enthalpy-driven process for fumaric acid, whereas no predominant effect is observed for succinic acid.

Fulvic acid mitigates cadmium toxicity-induced damage in cucumber seedlings through the coordinated interaction of antioxidant enzymes, organic acid, and amino acid.

Fulvic acid (FA) can significantly alleviate cadmium (Cd) stress, but the specific metabolic response of FA to Cd toxicity is still not clarified. In the present study, we used untargeted metabolomic [gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS)] analysis to profile cucumber metabolism in response to Cd stress after spray application of FA. Our results showed that 331 differentially enriched metabolites (DEMs) were identified in leaf materials. These DEMs were enriched in 21 shared pathways in comparative groups of "Cd treatment vs. the control treatment" and "FA + Cd treatment vs. the Cd treatment." Specifically, treatment with FA significantly enhanced the organic acid content (citric acid, isocitric acid, 2-oxoglutaric acid, fumaric acid, and malic acid), which would contribute to provide sufficient substrates for the tricarboxylic acid (TCA) cycle and amino acid biosynthesis, thereby ensuring the normal production of energy and amino acid. At the same time, FA significantly increased the amino acid content (aspartate, citrulline, histidine, leucine, and phenylalanine). The accumulation of organic acid and amino acid can act as chelating agents for heavy metal ions and as scavengers of reactive oxygen species (ROS), thereby reducing intracellular oxidative damage. Furthermore, the application of FA improves antioxidant enzymes and accelerates ROS clearance. The improved contents of organic acid and amino acid, and the increased activity of antioxidant enzymes both played a central role in the reduction of malondialdehyde (MDA, 14.08%), hydrogen peroxide (H2O2, 61.70%) contents, and superoxide anion radical (O2-, 30.41%) production rate in plants under Cd stress. Taken together, the present study demonstrates the effects of FA on the antioxidant capacity and carbohydrate and amino acid metabolism of cucumber seedlings exposed to Cd stress, which provides comprehensive insights into the regulation of plants' response to Cd toxicity with FA was applied in cucumber.

152 Normalization of the microbiome in psoriatic skin after treatment with fumaric acid esters (FAE), TNF, IL-17 or PDE4-inhibitors but not IL-12/23 blockade

The skin forms an interface between the body and the environment and provides distinct niches for microbial communities. Next-generation-sequencing used to characterize the cutaneous microbiome in psoriasis patients revealed an over-representation of Proteobacteria and a reduction of Actinobacteria in lesional skin, suggesting that the development of psoriatic plaques might be linked to specific alterations in the cutaneous microbiome and successful treatment could help to normalize the microbiome even before clinical parameters improve.

Differences of energy adaptation strategies in Tupaia belangeri between Pianma and Tengchong region by metabolomics of liver: Role of warmer temperature.

Global warming is becoming the future climate trend and will have a significant impact on small mammals, and they will also adapt at the physiological levels in response to climate change, among which the adaptation of energetics is the key to their survival. In order to investigate the physiological adaptation strategies in Tupaia belangeri affected by the climate change and to predict their possible fate under future global warming, we designed a metabonomic study in T. belangeri between two different places, including Pianma (PM, annual average temperature 15.01°C) and Tengchong (TC, annual average temperature 20.32°C), to analyze the differences of liver metabolite. Moreover, the changes of resting metabolic rate, body temperature, uncoupling protein 1content (UCP1) and other energy indicators in T. belangeri between the two places were also measured. The results showed that T. belangeri in warm areas (TC) reduced the concentrations of energy metabolites in the liver, such as pyruvic acid, fructose 6-phosphate, citric acid, malic acid, fumaric acid etc., so their energy metabolism intensity was also reduced, indicating that important energy metabolism pathway of glycolysis and tricarboxylic acid cycle (TCA) pathway reduced in T. belangeri from warmer habitat. Furthermore, brown adipose tissue (BAT) mass, UCP1 content and RMR in TC also decreased significantly, but their body temperature increased. All of the results suggested that T. belangeri adapt to the impact of warm temperature by reducing energy expenditure and increasing body temperature. In conclusion, our research had broadened our understanding of the physiological adaptation strategies to cope with climate change, and also provided a preliminary insight into the fate of T. belangeri for the future global warming climate.

Highly uniform Fe-based MOFs fabricated by mixed-linker strategy for ring-opening of epoxides with alcohols

Highly uniform nano-/micro-rods with a hexagonal shape of Fe-based MOFs (named as Mill-88-hmta) has been synthesized by using mixed-linker method towards the reaction between organic linkers (fumaric acid and hexamethylenetetramine) and Fe(NO3)3 via a solvothermal method. The as-prepared Mill-88-hmta MOFs exhibits excellent performance for ring-opening of epoxides with alcohols, which could be a promising candidate for other ring-opening reactions.

TMET-08. METABOLOMIC CHANGES IN GLIOBLASTOMA PATIENTS UNDERGOING CONCURRENT CHEMORADIATION THERAPY

Abstract OBJECTIVE To illustrate changes of untargeted metabolomics in patients with glioblastoma IDH wildtype undergoing concurrent radiation therapy (RT) with temozolomide (TMZ). This study implemented machine learning (ML) algorithms to predict treatment phase: pre-surgery, post-surgery, pre-radiation, and post radiation based on untargeted metabolomics data. METHODS Thirty-six patients with glioblastoma IDH wildtype (18 methylguanine methyltransferase [MGMT] methylated, 16 MGMT unmethylated, 2 MGMT status unknown) were enrolled into this study. Serum samples obtained from patients on the same day before surgery, 2 days after surgery, before starting their concurrent chemoradiation, and after concluding this phase of treatment. Blood samples were obtained via antecubital phlebotomy without regard for time of the day, diet, or fasting status. Untargeted metabolomics by GC-TOF mass spectrometry were obtained and compared. The proposed ML models analyzed 105 samples from 36 patients utilizing 157 structurally identified blood metabolites. Multinomial Logistic Regression (MLR) and GradientBoostingClassifier (GB Classifier) were used to classify patient samples based on detected changes in blood metabolites. The classification performance of these models was evaluated using performance metrics and AUC scores. RESULTS Post radiation; significant increase in the following metabolites: glycine, serine, threonine, oxoproline, 6-deoxyglucose, gluconic acid, glycerol-alpha-phosphate, ethanolamine, propyleneglycol, triethanolamine, xylitol, and fumaric acid were noted while significant decrease in 3-aminopiperidine 2,6-dione was noted post radiation. MLR produced 78% accuracy, 75% precision, and AUC = 0.89, and GB Classifier produced 75% accuracy, 77% precision and AUC = 0.91. Finally, we presented a pattern of metabolites changes per clinical stage based on pairwise correlations. CONCLUSIONS This study represent the first serum metabolic signature associated with RT in patients with glioblastoma. The results from the classification algorithms and pairwise correlations showed that blood metabolites have the potential to predict phase of treatment and potentially enable to evaluate response to treatment in patients with glioblastoma in a relatively small cohort.

Differentiation of qualified tea beverages from spoiled ones by the LC-MS–based analysis of their polycarboxylic acids

Abstract Polycarboxylic acids (PACs) are important metabolic products in almost all living bodies, yet current analytical methods for detection of PACs in tea beverages are still unsatisfactory due to the complex matrix and physicochemical properties of PACs. In this work, a rapid method was developed for the simultaneous determination of 7 PACs, including tartaric acid, α-ketoglutaric acid, malic acid, malonic acid, cis-aconitic acid, succinic acid, and fumaric acid, in beverages, based on selective removal of the matrix in combination with liquid chromatography–mass spectrometry (LC-MS) analysis. By stirring with activated carbon and the Na2CO3 solution, the matrix in beverages was selectively removed, and PACs were almost retained in the supernatant of diluted Na2CO3 solution. Under optimized parameters, the limit of quantitation for the PACs was in the range of 1–50 ng/mL, and the content of the PACs in 8 beverages was determined with the recovery range of 72.2%–122.5%. The contents of malic acid, malonic acid, and succinic acid in tea beverages were found to be greater than those in non-tea beverages. Moreover, the concentration of these PACs in beverages was found to be multiplied many times in their deterioration period, especially for fumaric acid and α-ketoglutaric acid. These results indicated that PACs can be selected as a criterion to differentiate qualified tea beverages from spoiled beverages.

Recent advances in microbial production of L-malic acid.

Over the last few decades, increasing concerns regarding fossil fuel depletion and excessive CO2 emissions have led to extensive fundamental studies and industrial trials regarding microbial chemical production. As an additive or precursor, L-malic acid has been shown to exhibit distinctive properties in the food, pharmaceutical, and daily chemical industries. L-malic acid is currently mainly fabricated through a fumarate hydratase-based biocatalytic conversion route, wherein petroleum-derived fumaric acid serves as a substrate. In this review, for the first time, we comprehensively describe the methods of malic acid strain transformation, raw material utilization, malic acid separation, etc., especially recent progress and remaining challenges for industrial applications. First, we summarize the various pathways involved in L-malic acid biosynthesis using different microorganisms. We also discuss several strain engineering strategies for improving the titer, yield, and productivity of L-malic acid. We illustrate the currently available alternatives for reducing production costs and the existing strategies for optimizing the fermentation process. Finally, we summarize the present challenges and future perspectives regarding the development of microbial L-malic acid production. KEY POINTS: • A range of wild-type, mutant, laboratory-evolved, and metabolically engineered strains which could produce L-malic acid were comprehensively described. • Alternative raw materials for reducing production costs and the existing strategies for optimizing the fermentation were sufficiently summarized. • The present challenges and future perspectives regarding the development of microbial L-malic acid production were elaboratively discussed.

Revealing the Pathogenesis of Salt-Sensitive Hypertension in Dahl Salt-Sensitive Rats through Integrated Multi-Omics Analysis.

Salt-induced renal metabolism dysfunction is an important mechanism of salt-sensitive hypertension. Given that the gut-liver axis is the first hit of a high-salt diet (HSD), we aimed to identify the extra-renal mechanism from hepatic metabolism and gut microbiota, and attempted to relieve the salt-induced metabolic dysfunctions by curcumin. Untargeted metabolomics analysis was performed to identify the changes in hepatic metabolic pathways, and integrated analysis was employed to reveal the relationship between hepatic metabolic dysfunction and gut microbial composition. HSD induced significant increase in fumaric acid, l-lactic acid, creatinine, l-alanine, glycine, and l-cysteine levels, and amino acids metabolism pathways associated with glycolysis were significantly altered, including alanine, aspartate, and glutamate metabolism; glycine, serine, and threonine metabolism, which were involved in the regulation of blood pressure. Integrated multi-omics analysis revealed that changes in Paraprevotella, Erysipelotrichaceae, and genera from Clostridiales are associated with metabolic disorders. Gene functional predication analysis based on 16S Ribosomal RNA sequences showed that the dysfunction in hepatic metabolism were correlated with enhanced lipopolysaccharide (LPS) biosynthesis and apoptosis in gut microbes. Curcumin (50 mg/kg/d) might reduce gut microbes-associated LPS biosynthesis and apoptosis, partially reverse metabolic dysfunction, ameliorate renal oxidative stress, and protect against salt-sensitive hypertension.

Diroximel Fumarate as a Novel Oral Immunomodulating Therapy for Relapsing Forms of Multiple Sclerosis: A Review on the Emerging Data.

Multiple sclerosis (MS) is a chronic inflammatory, demyelinating and neurodegenerative disorder of the central nervous system. Disease-modifying drugs (DMDs) and subsequent adherence are crucial for preventing reversible episodes of neurological dysfunction and delayed onset of progressive accumulation of irreversible deficits. Yet, side effects may limit their usage in clinical practice. Gastrointestinal (GI) side effects are a significant limitation of the use of dimethyl fumarate (DMF), the most frequently prescribed oral DMD in MS worldwide. Diroximel fumarate (DRF) is a second-generation oral fumaric acid ester (FAE) that was developed as a formulation with better GI tolerability. The improved tolerability is assumed to be related to a lower synthesis of gut-irritating methanol. Other explanations for DRF's lower extent of GI irritation include a more modest off-target activity due to its chemical structure. The superior GI tolerability of DRF compared to DMF could be proven in clinical trials and lead to approval of DRF for the treatment of relapsing forms of MS/relapsing-remitting MS (United States Food and Drug Administration and European Medicines Agency, respectively). Here, we summarize the mode of action of oral FAE and compare the chemical and physiological characteristics of DMF and DRF. Moreover, we discuss the adverse effects of FAE and introduce the emerging preclinical and trial data leading to the approval of DRF in MS. This article additionally reviews our current understanding of coronavirus disease 2019 (COVID-19) and the efficacy of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccination in people treated with FAE.

Above room temperature dielectric switchable organic co-crystal [C4H4O4]⋅[C3H9N] with Hirshfeld surface analyses

A new co-crystal [C 4 H 4 O 4 ]∙[C 3 H 9 N] was synthesized, where [C 4 H 4 O 4 ]=fumaric acid and [C 3 H 9 N]= isopropylamine. A reversible phase change happened at 352/357 K and it belongs to a homogenous phase change. Hirshfeld surface analyses reveal that three interactions of H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C contribute to more than 90% the total forces. Dielectric anomalies were also observed accompanied with structural phase change. • The forces of the H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C bond interactions by Hirshfeld surface analyses are different at the high and low dielectric states. We report a new dielectric phase change co-crystal [C 4 H 4 O 4 ]⋅[C 3 H 9 N] 1 , among which [C 4 H 4 O 4 ] is fumaric acid and [C 3 H 9 N] is isopropylamine / IPA. Single-crystal X-ray measurements show space group of 1 belongs to monoclinic P 2 1 / c space group, and a homogeneous phase change occurs. Hirshfeld surface analyses reveal that three interactions of H⋅⋅⋅H, H⋅⋅⋅O and H⋅⋅⋅C contribute more than 90 % to the total forces, and the forces of the three bonds are different at different phases. \

Celecoxib impairs primary human myoblast proliferation and differentiation independent of cyclooxygenase 2 inhibition

The use of non-steroidal anti-inflammatory drugs (NSAIDs) for treatment of musculoskeletal injuries is commonplace in the general, athletic, and military populations. While NSAIDs have been studied in a variety of tissues, the effects of NSAIDs on skeletal muscle have not been fully defined. To address this, we investigated the degree to which the cyclooxygenase (COX)-2-selective NSAID celecoxib affects muscle cell proliferation, differentiation, anabolic signaling, and mitochondrial function in primary human skeletal myoblasts and myotubes. Primary muscle cells were treated with celecoxib or NS-398 (a pharmacological inhibitor of COX-2) as a control. Celecoxib administration significantly reduced myoblast proliferation, viability, fusion, and myotube area in a dose-dependent manner, whereas NS-398 had no effect on any of these outcomes. Celecoxib treatment was also associated with reduced phosphorylation of ribosomal protein S6 in myoblasts, and reduced phosphorylation of AKT, p70S6K, S6, and ERK in myotubes. In contrast, NS-398 did not alter phosphorylation of these molecules in myoblasts or myotubes. In myoblasts, celecoxib significantly reduced mitochondrial membrane potential and respiration, as evidenced by the decreased citric acid cycle (CAC) intermediates cis-aconitic acid, alpha-keto-glutarate acid, succinate acid, and malic acid. Similar results were observed in myotubes, although celecoxib also reduced pyruvic acid, citric acid, and fumaric acid. NS-398 did not affect CAC intermediates in myoblasts or myotubes. Together, these data reveal that celecoxib inhibits proliferation, differentiation, intracellular signaling, and mitochondrial function in primary human myoblasts and myotubes independent of its function as a COX-2 inhibitor.

Antibacterial study on nickel and copper dicarboxylate complexes

Series of nickel and copper complexes with dicarboxylic acids (2,2′-thiodiacetic acid, 3,3′–thiodipropionic acid, 3,3′-dithiodipropionic acid, and fumaric acid) and N-donor ligands (1,2–diaminopropane, 1,3-diaminopropane, 1,10-phenanthroline and N,N,N′,N″,N″–pentamethyldiethylenetriamine) were synthesized and characterized using elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. These coordination compounds were tested for their antibacterial activities in vitro. The complexes demonstrated moderated antibacterial activity against Gram-positive and Gram-negative bacteria and could potentially be applied to treat skin wounds.

Impact of NaOH on the Hydrothermal Oxidation of Guaiacol for the Production of Value-Added Products

In this study, the impact of NaOH on the hydrothermal oxidation of guaiacol was investigated. It was found that NaOH significantly accelerated the production of formic acid and acetic acid with H2O2 or CuO as the oxidant. With the strong oxidant, H2O2, the highest acetic acid yield (15.73%) and formic acid (5.64%) were obtained at 300 °C for 90 s with NaOH 1.0 mol·L−1 and a 100% H2O2 oxygen supply. In comparison, with CuO as the oxidant, the highest values of acetic acid (13.42%) and formic acid (4.21%) were acquired at 250 °C for 6 h with NaOH 1.0 mol·L−1. Formic acid and acetic acid were generated through the oxidation of intermediates, such as levulinic acid, fumaric acid, maleic acid, etc. These results demonstrated that NaOH catalytic hydrothermal oxidation has potential for the production of value-added chemicals from biomass materials. When CuO is used as the oxidant, this process could also be used as a green method for copper smelting along with the utilization of lignin biomass.

Inheritance of Fruit Weight, Size and Organic Acid Content in a Distant Hybrid Population of Longan ‘Huanongzao’ and Lychee ‘Ziniangxi’

The type and content of organic acids in fruits are important factors that determine the traits, such as the nutrition and flavor of fruits. Fruit weight and size are also very important economic characters in fruit breeding research. To investigate the inheritance patterns in longan, fruit organic acid contents, weight, and size were measured in the distant hybridization progenies of longan ‘Huanongzao’ and lychee ‘Ziniangxi’. The results revealed that the malic acid accumulation exhibited mid-parent heterosis, citric acid content showed a tendency towards depression, and oxalic acid, ketoglutaric acid, fumaric acid, gallic acid, and total acid contents exhibited transgressive inheritance. The inheritance patterns in fruit weight, length and diameter tended towards smaller and degraded. The coefficient of variation (CV) for the organic acids ranged from 35.77–90.20%, and the heritability (H2) was 72.35–97.44%. High CV (55.44%) coupled with medium H2 (28.72%) were observed in fruit weight, however, low CV (12.29% and 12.50%) coupled with high H2 (68.95% and 69.25%) were shown in fruit length and diameter. In this study, the genetic variation of acid contents, fruit weight and size in the F1 population of longan and lychee were analyzed for the first time, providing an informative and theoretical basis for the selection and breeding of longan cultivars.

Sustainable Ketalization of Glycerol with Ethyl Levulinate Catalyzed by the Iron(III)-Based Metal-Organic Framework MIL-88A.

The catalytic properties of a simple iron-containing MOF based on fumaric acid, MIL-88A, were investigated in the ketalization of ethyl levulinate with glycerol. The corresponding product is a component of current interest as a renewable building block for many uses. Under the following conditions (solventless, 120 °C, stoichiometric ratio, 1% cat.), the reaction proceeds with good yields (85%), and the catalyst can be recovered and recycled without loss of activity, despite some changes in the crystalline lattice and morphology. Moreover, the residual iron content in the product is in the order of units of ppm (≤2), which demonstrates the robustness of the MOF under the reaction conditions.