Phenolic Products Research Articles

Hamamelitannin’s Antioxidant Effect and Its Inhibition Capability on α-Glycosidase, Carbonic Anhydrase, Acetylcholinesterase, and Butyrylcholinesterase Enzymes

Hamamelitannin (2′,5-di-O-galloyl-hamamelose) bears two-gallate moieties in its structure, and is a natural phenolic product in the leaves and the bark of Hamamelis virginiana. The antioxidant capacity of hamamelitannin was evaluated by a range of methods, with the following findings: the ability to reduce potassium ferric cyanide; the scavenging of N,N-dimethyl-p-phenylenediamine dihydrochloride radical (DMPD•+); the scavenging of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS•+); the scavenging of 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•); and the ability to reduce cupric ions (Cu2+). Additionally, reference antioxidants of α-Tocopherol, butylated hydroxyanisole (BHA), Trolox, and butylated hydroxytoluene (BHT) were used for comparison. For DPPH radical scavenging, hamamelitannin had an IC50 value of 19.31 μg/mL, while the IC50 values for BHA, BHT, Trolox, and α-Tocopherol were 10.10, 25.95, 7.05, and 11.31 μg/mL, respectively. The study found that hamamelitannin functioned similarly to BHA, α-tocopherol, and Trolox in terms of DPPH• scavenging, but better than BHT. Additionally, as a polyphenolic secondary metabolite, the hamamelitannin inhibition capability of several metabolic enzymes was demonstrated, including acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase I (CA I), carbonic anhydrase II (CA II) and α-glycosidase. The Ki values of hamamelitannin exhibited 7.40, 1.99, 10.18, 18.26, and 25.79 nM toward AChE, BChE, hCA I, hCA II, and α-glycosidase, respectively.

Validation of an UPLC-PDA Method for the Simultaneous Quantification of Phenol and Iomeprol in a Sterile Parenteral Preparation Used for Coeliac Plexus Block, and Its Application to a Pharmaceutical Stability Study

Objectives: A commonly applied analgesic therapy for patients with severe abdominal pain due to cancer-related pain in the upper abdomen, is coeliac plexus neurolysis (CPN). Herein, a combination product of phenol and an iodine contrast agent are injected simultaneously. The chemical stability of such a combination product is unknown, and no chromatographic method is yet available that describes the simultaneous quantification of phenol and iomeprol. The aim of this study was to develop and validate a stability-indicating UPLC method for the simultaneous quantification of both phenol and iomeprol and to determine the chemical stability of a sterile 100 mg/mL phenol in 350 mg I/mL iomeprol solution for injection during shelf life. Methods: The product was compounded and sterilized in a GMP certified facility. The pharmaceutical analysis was validated by determination of the accuracy, precision, specificity, selectivity, carry-over and linearity. Pharmaceutical product stability was determined before and after sterilization, and during shelf life of 36 months at 25°C ± 2°C. Results: The accuracy for phenol and iomeprol was 97.1% to 99.3% and 100.0% to 100.2%, respectively. The RSD for repeatability and reproducibility for phenol were 0.65% and 1.17%, and for iomeprol 0.61% and 1.49%, respectively. All other tested parameters met the predefined validation criteria. All concentrations at all tested time points remained within ±2% of the initial concentrations for phenol and ±4% for iomeprol. No additional peaks were visible on the chromatograms. Conclusion: A stability-indicating method for the simultaneous quantification of phenol and iomeprol in a parental pharmaceutical preparation was developed and validated. This method was used to demonstrate the chemical stability of a newly developed sterile solution of 100 mg/mL phenol and 350 mg I/mL iomeprol. Chemical product stability was demonstrated during shelf life of up to 36 months.

In-depth exploration of waste printed circuit boards pyrolysis: Real-time products characteristics, kinetics parameter optimization and reaction mechanism

Pyrolysis is a promising technology for recycling waste printed circuit boards (WPCBs). This study delves into a real-time examination of the volatiles emitted from WPCBs during pyrolysis using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy/mass spectrometry (TG-FTIR/MS), offering an in-depth analysis of the entire pyrolysis mechanism. An optimized kinetic model for printed circuit board (PCB) pyrolysis is developed by the shuffled complex evolution (SCE) algorithm. Results indicate that the main pyrolysis products are phenol and alkyl-substituted phenols, along with hydrogen bromide (HBr) and bromophenols. Bromides exhibit an earlier onset and peak temperature compared to phenolic products. The pyrolysis process can be divided into two stages: initial depolymerization of the resin body into macromonomers, followed by prevalent alkyl removal, homolytic reactions, and isomerization. The apparent activation energy (E) is 155.32 kJ/mol, the pre-exponential factor (ln(A)) is 29.77 min−1, and the kinetic mechanism function is described by (1‐α)2.02. This study provides crucial knowledge to advance the technology of WPCBs pyrolysis.

Recycling Valuable Phenol from Polycarbonate Plastic Waste Via Direct Depolymerization and Csp2-Csp3 Bond Cleavage Under Mild Conditions.

Upcycling plastic waste into commodity chemicals is recognized as an environmentally benign solution and beneficial for the sustained growth of humanity. Nevertheless, transition metal-free catalysts and energy-efficient conditions pose significant challenges due to the robust mechanical properties of plastics. Here, a strategy for selective production of phenol by upcycling polycarbonate waste via direct depolymerization and Csp2-Csp3 bond cleavage in an aqueous medium under mild conditions is reported. The commercial zeolites efficiently catalyze the depolymerization, Csp2-Csp3 bond hydrolysis, and direct Csp2-Csp3 bond scission at Cα of PC. Among all evaluated zeolites, HY (Si/Al=15) showed excellent catalytic performance, attributed to the ~75 % yield of phenol and ~15 % of acetone. The approach also employs different municipal waste PC for upcycling. Studies reveal that HY (15) exhibits high catalytic efficiency and phenol yield due to its optimum acid sites and textual properties. A scale-up experiment demonstrated that 3.1 g of phenol was produced from 5.0 g of PC, and the mass balance was 90 %. A combination of control experiments, NMR analysis, and DFT studies proposed the reaction pathway. Our findings present a sustainable avenue for upcycling PC waste and offer a new way to produce phenol, contributing to the advancement of a circular economy.

A deep eutectic solvent with a lignin stabilization and functionalization for lignocellulosic biomass pretreatment

This study synthesized a functional deep eutectic solvent (DES) using betaine and glyoxylic acid (GA) for lignocellulosic biomass pretreatment. The Betaine/GA DES pretreatment resulted a high delignification efficiency of 81.89% and xylan removal of 83.25% while preserving most of cellulose. During pretreatment, lignin was stabilized by GA, preventing its condensation and introducing carboxyl groups onto its molecular backbone. The GA stabilized lignin (GASL), with a high β-O-4 linkage content of 62.92%, was depolymerized for phenolic monomer production with a bio-oil yield of 55.40%. Additionally, the functional lignin was used as a surfactant for GASL-based O/W emulsion (GA-O/W emulsion) preparation. With 0.5% of lignin addition and an optimal O/W ratio of 6:4, the resulting GA-O/W emulsion exhibited a high cream index value of 100% and excellent storage stability without any phase transition or emulsion aggregation. When using the lignin to prepare curcumin-encapsulated microcapsules, a cumulative curcumin remaining of 74.19% under UV radiation and an extraordinary encapsulation efficiency of 62.86% were achieved. Furthermore, this DES pretreatment promoted enzymatic saccharification of the pretreated cellulose substrate, resulting in a glucose yield of 91.49%. After adding 15 wt% of the fibers in soft wood pulp for papermaking, the tear index, ring crush strength index, and tensile index of the produced paper-sheets reached 112.04%, 98.58%, and 83.55% of those of the pure softwood pulp papers, respectively.

Methyl jasmonate mitigates biochemical and phytochemical changes in salt stressed Stevia rebaudiana plants

This study explored the effects of salt stress on growth, oxidative stress, and steviol glycoside content in Stevia rebaudiana Bertoni plants cultivated in soil supplemented with methyl jasmonate (MeJA). Stevia plants were cultivated under normal and salt stress conditions, with and without MeJA supplements of 30 ?M, 60 ?M, and 120 ?M. Samples were harvested after the 1st, 3rd, 5th, 10th, and 15th day of treatment. The levels of chlorophyll (p<0.0001), carotenoids (p<0.0001), and antioxidant enzymes such as catalase (p<0.0001), superoxide dismutase (p<0.0001), APX (p<0.0001), and glutathione reductase (p<0.0001) were observed. The quantification of steviol glycosides, including stevioside (p<0.0001) and rebaudioside-A (p<0.0001), was studied by the most advanced hyphenated technique, LC-MS/MS. The study revealed that the oxidative stress responses were significantly improved in MeJA-treated plants compared to salt-stress control plants. The level of production of phenols (p<0.0001), flavonoids, total sugar, reducing sugar, and steviol glucosides was significantly altered in salt-stress plants. MeJA showed a dose- and time-dependent significant effect on the improvement of these factors over salt stress. In conclusion, MeJA not only improves the growth of plants but also reduces oxidative stress and enhances the level of phytochemicals under saline stress.

Diiodine–Triethylsilane System: A Practical Method for Deprotection of Aryl Benzyl Ethers

AbstractA practical method for the debenzylation of aryl benzyl ethers has been developed using easy-to-operate I2 and Et3SiH, as well as the green solvent ethyl acetate. Halo, methoxy, ester, and nitro groups on the benzene ring of the aryl benzyl ether are compatible with this debenzylation. Control experiments revealed that Et3SiI, generated in situ, might be the actual promoter of the procedure. This method does not require a separate desilylation reaction to obtain phenol products.

Alkaline treatment for targeted lignin breakdown in rice straw: Maximizing phenolic content and product characterization

Lignin is a significant renewable source for the production of phenolics and aromatic compounds for use as functional materials. Rice straw (RS), a lignocellulosic biomass was given alkaline treatment, to breakdown lignin into methoxyphenols and heterocyclic compounds, leaving behind carbohydrate rich residue. Process parameters such as NaOH (M), time (min) and liquid to solid (L:S) ratio (mL/g) were optimized using Response Surface Methodology (RSM) to enhance the extraction of phenolics. The maximum phenolic content (13.98 mg/g RS) was obtained after treatment with 3 M NaOH for 30 min with L: S ratio of 20:1 mL/g at 121°C. GC-MS revealed the presence of 14 compounds, primarily methoxyphenols like acetosyringone (32.44 %), 2-methoxy-4-vinyl phenol (23.71 %), vanillin (1.25 %) and 2, 6-dimethoxyphenol (1.49 %). Additionally, a significant proportion of a heterocyclic compound, 2, 3-dihydrobenzofuran (31.72 %), was also present. The extract exhibited considerable levels of 2, 2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) (IC50 (half-maximal inhibitory concentration) = 0.45 mg/mL) radical scavenging activity, which was comparable to ascorbic and gallic acids. With substantial conversion (60.17 %) of rice straw lignin to phenols and simultaneous recovery of both cellulose (45.7 %) and hemicellulose (14.6 %), this process can be useful in biorefining of lignocellulosic biomass to phenolic chemicals for application in food and pharmaceutical industry.

Propane wet reforming over PtSn nanoparticles on γ-Al2O3 for acetone synthesis

Acetone serves as an important solvent and building block for the chemical industry, but the current industrial synthesis of acetone is generally accompanied by the energy-intensive and costly cumene process used for phenol production. Here we propose a sustainable route for acetone synthesis via propane wet reforming at a moderate temperature of 350 oC with the use of platinum-tin nanoparticles supported on γ-aluminium oxide (PtSn/γ-Al2O3) as catalyst. We achieve an acetone productivity of 858.4 μmol/g with a selectivity of 57.8% among all carbon-based products and 99.3% among all liquid products. Detailed spectroscopic and controlled experiments reveal that the acetone is formed through a tandem catalytic process involving propene and isopropanol as intermediates. We also demonstrate facile ketone synthesis via wet reforming with the use of different alkanes (e.g., n-butane, n-pentane, n-hexane, n-heptane, and n-octane) as substrates, proving the wide applicability of this strategy.

Pyrolysis of hyphaene thebaica shell over ceramic tile dust-derived catalysts and assessment of the produced bio-oil

The purpose of this study is to demonstrate the potential of ceramic tile dust (CTD)-derived ZSM-5 zeolite (CZ) and its monodispersed composite with metal oxides (MgO and Fe2O3) in the catalytic pyrolysis of hyphaene thebaica shell (HTS). The HTS was pyrolysed in a Fixed-bed reactor at 400–600 °C, and 100–300 mL/min N2 flowrate. The maximum bio-oil production of 32 % was obtained at 500 °C and 150 mL/min N2 flowrate, with bio-oils containing 50 % acid and octadecenoic acids, as well as esters, phenols, aldehydes, ketones, ethers, aromatics, and hydrocarbons. A carboxymethyl cellulose templating agent was employed for the mesoporous zeolite synthesis from CTD. This resulted in the mesoporous zeolite with a predominant ZSM-5 crystal phase, exhibiting pore diameters ranging from 1.8-6 nm, 229 m2/g surface area and 1145 μmol/g total acidity. The catalytic pyrolysis of HTS was conducted using the ZSM-5 zeolite (CZ) and metal-oxide (MgO, Fe2O3, and Fe2O3/FeO) modified CZ, as monodispersed composite catalysts. Under best thermal pyrolysis conditions, CZ-Fe2O3, CZ-MgO, and CZ-Fe2O3/MgO demonstrated 22–23 % bio-oil yields. Notably, the CZ-Fe2O3/MgO catalyst exhibited the highest hydrocarbon yield at 16 %, while the CZ-MgO favoured the production of phenolics, esters, and alcohols. CZ-MgO also displayed the highest coking level at 7.5 %, indicating faster deactivation than the other catalysts. The synthesised catalysts exhibited remarkable catalytic activity, resulting in a notable improvement in the quality of bio-oils obtained from the intermediate pyrolysis of hyphaene thebaica shells in a fixed-bed reactor.

In-situ and ex-situ selective catalysis of biochar-based catalysts for the production of high-quality bio-oil and H2-rich gas from tobacco stem

Optimizing the catalytic pyrolysis process is a promising approach to enhance the quality of the resulting products. Thus, four metals (Ni, Fe, Co, Cu) were loaded on biochar support to prepare biochar-based catalysts, and the mechanism of its effect on quality improvement of bio-oil and pyrolysis gas during in-situ and ex-situ pyrolysis of tobacco stem was investigated. The results showed that the biochar-based catalyst has high selectivity for H2-rich and phenols production during in-situ pyrolysis, while the phenols content reached 57.99 % and H2 content reached 49.91 % in Fe@BC group. It is highly selective to H2-rich and N-containing compounds during ex-situ pyrolysis, and the content of N-containing compounds reached 47.23 % and the content of H2 reached 47.59 % in the Ni@BC group. This contributes to the efficient use of high-quality bio-oils and the production of clean gases. Biochar-based catalysts hold significant potential for the pyrolysis industry, paving the way for large-scale production and application of high-quality pyrolysis products.

Comparison of the pyrolysis behavior of PC, ABS and PC/ABS

Three types of plastics—polycarbonate (PC), acrylonitrile-butadiene-styrene (ABS), and PC/ABS blend—were studied in this work. Kinetic analyses were performed using the Flynn-Wall-Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) methods. The evolved volatiles during the pyrolysis of each material were analyzed, and the pyrolysis behavior was proposed using in-situ tools such as thermogravimetric analyzer-Fourier transform infrared spectroscopic (TG-FTIR) and gas chromatographic separation and mass spectrometry detection (Py-GC/MS). The three samples were also pyrolysed in a fixed bed reactor to elucidate the impact of secondary reaction. For PC, the activation energy increases as the reaction progresses. PC primarily generated CO2 and oxygenated compounds. For ABS, the activation energy experienced a slight decrease once the depolymerization reaction initiates, while a reversed trend can be observed at higher conversion rates. ABS pyrolysis mainly produced nitrogen-containing compounds and mono-aromatics. In the case of PC/ABS blend, a distinctive two-stage decomposition mechanism was observed. The interaction between PC and ABS in the blend promoted the formation of N/O-containing compounds. Additionally, this interaction enhanced the production of lighter phenols at the expense of bisphenol A, while ABS was not affected markedly. Stronger re-condensation and cracking reactions in the fixed bed system, facilitated the formation of poly-aromatics and lighter phenols (p-cresol and 4-ethylphenol) at the expense of bisphenol A during the pyrolysis of PC. In contrast, styrene from ABS decomposition was weakly affected by the secondary reaction. The intensified secondary reactions occurring the sample bed of the fixed bed experiments can also enhance the interaction between volatiles from ABS and PC, forming more heterocyclic N-compounds.

Synergistic magnetic Cu-Fe catalysts on N-doped biochar for efficient alkali lignin catalytic depolymerization into monophenols

Alkali lignin, a major by-product of papermaking, poses disposal challenges, hindering the full valorization of lignocellulose in sustainable biorefineries. One-pot lignin catalytic depolymerization (LDP) in water offers a promising route for producing valuable phenolic compounds. This study reports the successful synthesis of in-situ N-doped biochar supported CuxFey catalysts (CuxFey/N-BC) via a one-step carbothermal reduction method, enabling LDP in water without the need for external hydrogen, additives, alcohol solvent, or co-catalysts. Notably, the Cu5Fe1/N-BC could achieve remarkable catalytic performance under mild reaction conditions (280 °C, 6 h, 18 mL water), yielding 80.84±2.23 mg/g of monophenol, 56.17±1.32 % of bio-oil, and a lignin conversion rate of 80.66±0.73 %. This significantly surpassed the performance of monometallic catalysts and bare biochar. The synergistic effects of intermetallic interactions and nitrogen doping were proposed to create abundant active sites and rich pore structures, promoting efficient LDP reactions. Furthermore, the Cu5Fe1/N-BC exhibited excellent recyclability, with minimal activity loss (2.79 %) per cycle, due to its strong magnetism and favorable interactions. Mechanism investigation revealed that the Cu5Fe1/N-BC efficiently cleaved the C-O and C-C bonds in lignin, and led to the targeted production of guaiacyl phenols. This study provides valuable insights and practical strategy for valorizing lignin into valuable chemicals, advancing its utilization in various applications.

Enhanced production of health-promoting phenolic compounds using a novel endophytic fungus Talaromyces neorugulosus R-209 isolated from pigeon pea in a natural habitat by l-phenylalanine feeding.

In this study, nine endophytic fungi capable of producing multiple phenolic compounds were screened and identified from 152 fungi isolated from pigeon pea in a natural habitat (Honghe, Yunnan Province, China). Talaromyces neorugulosus R-209 exhibited the highest potential for phenolic compound production. L-phenylalanine feeding was used to enhance phenolic compound production in T. neorugulosus R-209 cultures. Under the optimal feeding conditions (l-phenylalanine dose of 0.16g/L and feeding phase of 6 days), the yields of genistein, apigenin, biochanin A, and cajaninstilbene acid increased by 15.59-fold, 7.20-fold, 25.93-fold, and 10.30-fold over control, respectively. T. neorugulosus R-209 fed with l-phenylalanine was found to be stable in the production of phenolic compounds during ten successive subcultures. Moreover, bioactivities of extracts of T. neorugulosus R-209 cultures were significantly increased by l-phenylalanine feeding. Overall, l-phenylalanine feeding strategy made T. neorugulosus R-209 more attractive as a promising alternative source for the production of health-beneficial phenolic compounds in the nutraceutical/medicinal industries.

Geography and associated bioclimatic factors differentially affect leaf phenolics in three ivy species (Hedera L.) across the Iberian Peninsula

The biosynthesis of secondary metabolites in plants, especially that of phenolic compounds, is stimulated to protect against several environmental stress factors such as cold temperatures, drought, and UV-irradiance. As a result, when a species occurs under different climatic conditions, differences in phenolic accumulation are expected across species distribution in response to the environmental cues. However, our understanding of phenolic compounds' natural variation is limited, as most of our knowledge on secondary metabolite biosynthesis stems from experimental studies conducted under controlled conditions. In this study we analyze phenolic content and its relation to climatic and geographic variation in three closely related Hedera species (H. helix, H. hibernica and H. iberica) across their southwestern range limits in the Iberian Peninsula (82 populations, 401 individuals). The Iberian Peninsula concentrates the highest global species richness of Hedera, with the three species sharing range boundaries along the latitudinal and longitudinal climatic gradient of the region. We found that the three species exhibited different climatic and geographic patterns of phenolic content variation in the study area. The phenolic production in H. helix increased with elevation in relation to the decrease of temperature and the increase of temperature contrast, whereas in H. hibernica varies with latitude in relation to summer temperature and precipitation regimes, increasing in areas with no summer drought. In contrast, we did not find any environmental variables associated with phenolic content in H. iberica, likely due to its narrow geographic and climatic range and a higher influence of microclimatic conditions. Although the three Hedera species are closely related, our results suggest that leaf phenolic production may be triggered by different environmental conditions in each species. Our study underscores the species-specific nature of phenolic compounds' role in plant stress response.

Critical areas for <i>Brettanomyces bruxellensis</i> contamination and biofilm formation in the cellar: on the origin of wine spoilage

The cellar environment harbours a consortium of microorganisms on the material surfaces and in the air. Among these microorganisms, the spoilage yeast Brettanomyces bruxellensis can colonise surfaces due to its specific bioadhesive properties. In this study, air and surface samples were collected in several wineries during the winter period. B. bruxellensis was detected in the cellar environment either in the air or on the surfaces of various materials, including in tartaric acid precipitates. Difficult-to-clean tank equipment (taps, wall angles, valves) were identified as critical areas where B. bruxellensis was frequently detected. To confirm that surfaces contaminated by B. bruxellensis could be involved in wine contamination, yeast growth and volatile phenol production were monitored in wine in contact with stainless steel harbouring biofilms. The presence of bioadherent cells and biofilms in contact with the wine resulted in significant cell release into the wine, leading to population growth and the production of volatile phenols at concentrations above the olfactory detection threshold. This study demonstrates the possibility of wine spoilage by resident and adherent populations of B. bruxellensis and confirms the need to pay special attention to the hygiene of hard-to-reach areas such as valves.

Effect of salt stress on growth and phenolic compounds production in callus suspension culture of the dioecious species thyrse sorrel (Rumex thyrsiflorus Fingerh.)

The sex-dependent differences in the response to salt stress of the dioecious Rumex thyrsiflorus and the influence of different concentrations of sodium chloride (NaCl) on the biosynthesis of phenolic compounds in callus suspension cultures were evaluated. The cultures originated from callus obtained on hypocotyls isolated from male and female seedlings were cultured on Murashige and Skoog medium supplemented with 0.4 mg/L 6-benzylaminopurine and 1 mg/L 2,4-dichlorophenoxyacetic acid. The results showed that the response to salt stress depends on both the sex of the plant and the NaCl concentration in the culture medium. The analysis of the main morphometric parameters showed that callus tissue derived from the hypocotyls of female seedlings was less sensitive to salt stress than that from male seedlings, which was correlated with higher concentrations of phenolic compounds. The optimal NaCl concentration to increase the production of phenolic compounds was 129 mM for females and 43 mM for males. In the methanolic tissue extracts 22 compounds were determined using the HPLC–DAD method. In general, higher amounts of compounds were detected in the extracts from the female tissue. The following dominated: catechin (max. 213.31), cryptochlorogenic acid (max. 76.35) and epicatechin (max. 54.84) (mg/100 g DW). This comprehensive phytochemical analysis of the sex-related aspects of the response to salt stress was performed for the first time in this dioecious model species. The results revealed potential application of NaCl as the ecological friendly and inexpensive elicitor to increase the production of pharmaceutically valuable compounds and highlight the importance of dioecy in phytochemistry.

Prevention and Control of Ginger Blast by Two Fumigants and Their Effects on a Soil Bacterial Community and the Metabolic Components of Ginger

A two-year field trial was conducted in order to assess techniques to control ginger blast and explore the effects of fumigants on soil bacterial microorganisms and ginger metabolites. This study examined the effects of dazomet and chloropicrin on the control of ginger blast and their influence on ginger yield in Luoping County, Yunnan Province, China. The results showed that in 2022, the control effectiveness of dazomet and chloropicrin treatments on ginger blast was 84.33% and 94.67%, respectively. The corresponding yields were 50,154.40 kg/hm2 and 50,296.90 kg/hm2. In 2023, the control effectiveness of dazomet and chloropicrin treatments on ginger blast were 86.33% and 93.67%, respectively, and the yields were 65,115.83 kg/hm2 and 65,337.93 kg/hm2. In both years, the incidence of ginger blast in the control group reached nearly 100%, leading to the near extinction of the crop. Additionally, in 2023, 16S rRNA high-throughput sequencing and non-targeted metabolomics techniques were used to analyze the effects of the fumigants on soil bacterial microorganisms and the metabolites in ginger. The results showed that the diversity and richness of soil bacterial communities were lower than those in the control group at 0 and 120 days after treatment with two fumigants, but the relative abundances of beneficial bacteria such as Pseudomonas increased at 60 days, and the relative abundances of Actinobacteria, Gemmatimonadetes, and Bacillus increased at 120 days. The abundance of Firmicutes also increased after 120 days of chloropicrin treatment. The non-targeted metabolic LC–MS results showed that the production of phenols and terpenoids was upregulated after dazomet and chloropicrin treatments. The contents of amino acids and their derivatives were also upregulated. This upregulation of metabolites was beneficial to the flavor quality of ginger and enhanced its anti-inflammatory, anti-tumoral, and antioxidant effects.

Selective production of phenol from the end-of-life wind turbine blade through catalytic pyrolysis

This study employed catalytic pyrolysis to enhance the selectivity and yield of phenol in the pyrolysis oil derived from the end-of-life wind turbine blade (WTB). It was confirmed that the NiO(10)/Al2O3 catalyst exhibited the best activity, reaching a phenol selectivity of 28.57 % at 500 °C with a heating rate of 10 °C/min. Furthermore, a competitive phenomenon between the catalytic formation of phenol and that of gaseous products was observed. Characterization results indicated that at lower loading content of NiO on the Al2O3 carrier, NiAl2O4 crystals tended to form preferentially, which reduced catalyst activity by covering surface strong acid sites. With increasing the loading content of NiO, saturation of NiAl2O4 formation occurred, and free NiO crystals became dominant. This resulted in the creation of abundant Lewis acid sites, enhancing the catalytic formation of phenol. Whilst, excessive accumulation of free NiO crystals increased strong acid sites and significantly generated lattice oxygen, promoting the cracking of pyrolysis oil to gaseous products, which was detrimental to phenol enrichment but facilitated the production of H2-rich syngas. The conclusions offered valuable insights for upgrading pyrolysis products derived from epoxy resin polymers during the recovery of end-of-life WTB.

Untargeted metabolomics combined with chemometrics reveals distinct metabolic profiles across two sparkling cider fermentation stages

This study aimed to examine the metabolic profiles of Saccharomyces cerevisiae yeasts (WLS21 and Y41) in two phases of sparkling cider making (normal and pressure fermentation) by combining untargeted metabolomic with chemometrics. The results showed that of the 634 nonvolatile metabolites identified using LC-MS and 83 volatile metabolites identified by GC–MS, the differential metabolites were 226 and 54, respectively. Metabolic pathway and correlation analyses showed that aspartic acid, phenylalanine and tyrosine, glutamic acid and purine metabolism were associated with flavor formation. The pressure fermentation process increased apigenin, naringenin, toxifolin, pyridoxine and thiamine contents in the final cider. These findings provide useful information and new research ideas for the formation of flavor in sparkling cider and the regulation of phenolic and vitamin production by microbial stress fermentation.