Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels usin...Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.展开更多
Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space missions.To improve the ablative properties,s...Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space missions.To improve the ablative properties,silica sol with good particle size distribution prepared using tetramethoxysilane(TMOS)was blended with natural rubber latex and deposited onto carbon fiber felt,which was then integrated with phenolic aerogel matrix,introducing nano-silica into the framework of CFPA.The modified CFPA with a low density of 0.28—0.31 g/cm3exhibits strain-in-fracture as high as 31.2%and thermal conductivity as low as 0.054 W/(m·K).Furthermore,a trace amount of nano-silica could effectively protect CFPA from erosion of oxidizing atmosphere in different high-temperature environments.The oxyacetylene ablation test of 3000°C for 20 s shows a mass ablation rate of 0.0225 g/s,a linear ablation rate of 0.209 mm/s for the modified CFPA,which are 9.64%and 24.82%lower than the unmodified one.Besides,the long-time butane ablation test of 1200°C for 200 s shows an insignificant recession with mass and linear ablation rate of 0.079 g/s and 0.039 mm/s,16.84%and 13.33%lower than the unmodified one.Meanwhile,the fixed thermocouple in the test also demonstrates a good thermal insulation performance with a low peak back-face temperature of 207.7°C,12.25%lower than the unmodified one.Therefore,the nano-silica modified CFPA with excellent overall performance presents promising prospects in high-temperature aerospace applications.展开更多
The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability,environmental friendliness,and non-toxicity is of great importance.Herein,a series of Co-based catalysts,named...The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability,environmental friendliness,and non-toxicity is of great importance.Herein,a series of Co-based catalysts,named Co@NCNTs,were designed and constructed by direct pyrolysis of hollow ZIF-67(HZIF-67)under H_(2)/Ar atmosphere.The evolution of the catalyst surface from the shell layer assembled by ZIF-67-derived particles to the in situ-grown hollow nitrogen-doped carbon nanotubes(NCNTs)with certain length and density is achieved by adjusting the pyrolysis atmosphere and temperature.Due to the synergistic effects of in situ-formed hollow NCNTs,well-dispersed Co nanoparticles,and intact carbon matrix,the as-prepared Co@NCNTs-0.10-450 catalyst exhibits superior catalytic performance in the hydrogenation of phenolic compounds to alcohols.The turnover frequency value of Co@NCNTs-0.10-450is 3.52 h^(-1),5.9 times higher than that of Co@NCNTs-0.40-450 and 4.5 times higher than that of Co@NCNTs-0.10-550,exceeding most previously reported non-noble metal catalysts.Our findings provide new insights into the development of non-precious metal,efficient,and cost-effective metal-organic framework-derived catalysts for the hydrogenation of phenolic compounds to alcohols.展开更多
The purpose of this study is to investigate the physicochemical properties of some local varieties of onion (Allium cepa L.) and compare them with an imported variety, all collected in May 2021. Proteins, reducing sug...The purpose of this study is to investigate the physicochemical properties of some local varieties of onion (Allium cepa L.) and compare them with an imported variety, all collected in May 2021. Proteins, reducing sugars, lipids, and polyphenol content were estimated according to the AFNOR standardized methods. The determination of calcium, magnesium, iron, sodium, potassium and phosphorus was performed by atomic absorption spectrophotometer coupled with a CCD detector. The results highlighted an average acidity of 0.377% ± 0.002% lower than the value of the imported variety which is 0.520% ± 0.001%. Local varieties have a pH ranging from 6.35 ± 0.003 to 6.42 ± 0.004, while the variety has a pH of 6.36 ± 0.003. The ash and dry matter contents vary respectively from 4.788% ± 0.004% to 8.253% ± 0.003% and 7.945% ± 0.021% to 11.945% ± 0.007% for the local varieties. Moreover, the imported one has ash and dry matter contents of 5.175% ± 0.007% and 10.035% ± 0.021% respectively. The results show that the protein, reducing sugar and lipid contents in the local onion varieties vary respectively from 2.815 ± 0.000 to 15.634 ± 0.001 g·100 g<sup>-1</sup>;4.691 ± 0.001 to 12.596 ± 0.002 g·100 g<sup>-1</sup> and 0.006 ± 0.001 to 0.050 ± 0.057 g·100 g<sup>-1</sup>. Furthermore, the imported variety has a protein, reducing sugar and lipid content of 5.649 ± 0.002;8.565 ± 0.002 g·100 g<sup>-1</sup> and 0.011 ± 0.010 g·100 g<sup>-1</sup> respectively. The maximum levels of total polyphenols are obtained in the imported variety, Bellani and Gandiol, respectively 9.973 ± 0.001, 4.535 ± 0.002, and 3.425 ± 0.006 mg EAG/g of dry matter. The local varieties have a significant calorific intake of between 35.451 ± 0.001 and 112.980 ± 0.003 kcal·100 g<sup>-1</sup> compared to the imported one with an energy value of 56.953 ± 0.001 kcal·100 g<sup>-1</sup> of dry matter. The bulbs of different onion varieties studied have a fairly high content of mineral elements. The potassium content of local varieties is between 502.16 ± 0.06 mg·100 g<sup>-1</sup> and 582.77 ± 0.04 mg·100 g<sup>-1</sup> while the imported variety has a content of 536.62 ± 1.30 mg·100 g<sup>-1</sup>. They note that the local varieties have a better calcium content (249.75 ± 0.07 to 434.20 ± 0.57 mg·100 g<sup>-1</sup>) and magnesium (142.15 ± 0.07 to 162.60 ± 0.42 mg·100 g<sup>-1</sup>) than the imported variety (229.58 ± 0.04 mg·100 g<sup>-1</sup>) except for the varieties White Grano (228.29 ± 0.01 mg·100 g<sup>-1</sup>) and Rouge Amposta (117.00 ± 0.42 mg·100 g<sup>-1</sup>) respectively. These results reveal that Gandiol, Dayo and Orient F1 are nutritionally found better due to their higher antioxidant property, proteins, carbohydrates, and reducing sugar and should be included in diets to supplement our daily allowance needed by the body.展开更多
The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity o...The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .展开更多
Whole grains of proso and barnyard millets were sequentially extracted using different solvents(hexane,chloroform,ethyl acetate,and methanol).Phytochemical analysis was performed qualitatively,and the total phenolic c...Whole grains of proso and barnyard millets were sequentially extracted using different solvents(hexane,chloroform,ethyl acetate,and methanol).Phytochemical analysis was performed qualitatively,and the total phenolic content in the extracts of proso and barnyard millets was quantified.Alkaloids and cardiac glycosides were identified in all solvent extracts of both millets.Anthraquinone and glycosides yielded negative results in all solvent extracts of both millets.Among all the solvent extracts,methanol extracts of proso and barnyard millets showed the presence of major compounds such as flavonoids,terpenoids,amino acids,tannins,and phenolics compounds.The maximum amount of phenols was found in methanolic extracts of proso and barnyard millets(0.669±0.003 and 0.625±0.003),followed by the chloroform extract of proso and barnyard millets(0.284±0.002 and 0.257±0.003).The minimum amount of phenolics was found in the acetone extract of proso and barnyard millets.The methanol extract of both millets showed the presence of major compounds with high phenolic content.展开更多
Phenolic wastewater is one of the priorities in the field of wastewater treatment,which poses a serious threat to the human health and nature environment.In this paper,cationic cetyltrimethylammonium bromide(CTAB)and ...Phenolic wastewater is one of the priorities in the field of wastewater treatment,which poses a serious threat to the human health and nature environment.In this paper,cationic cetyltrimethylammonium bromide(CTAB)and anionic sodium oleate(Na OL)microemulsions were utilized to extract phenol from the wastewater.The optimal extraction factors were investigated by exploring the effects of microemulsion composition ratio and extraction conditions on the phenol extraction performance.Furthermore,the enhanced extraction mechanism of phenol by cations microemulsions is illustrated by studying the extraction process of cationic and anionic microemulsions in the extraction of phenol.The optimum components were obtained:surfactant concentration of 0.2 mol·L^(-1),isoamyl alcohol volume of 30%,internal aqueous phase concentration of CTAB microemulsion of 0.05 mol·L^(-1),and internal aqueous phase concentration of Na OL microemulsion of 0.09 mol·L^(-1).The extraction efficiencies were 96.44%and 82.0%when using CTAB and Na OL microemulsions under optimal conditions(water-emulsion ratio of 5,contact time of 9 min,extraction temperature of 298.15 K,and p H of 9),confirming the enhanced extraction of phenol by CTAB cationic microemulsion.It was analyzed that the enhanced extraction of CTAB microemulsion was due to the electrostatic adsorption of cations with phenol root ions.展开更多
[Objectives]This study was conducted to provide a theoretical basis for the extraction and comprehensive utilization of functional active components of Chrysanthemum morifolium polyphenols.[Methods]With C.morifolium a...[Objectives]This study was conducted to provide a theoretical basis for the extraction and comprehensive utilization of functional active components of Chrysanthemum morifolium polyphenols.[Methods]With C.morifolium as a raw material,polyphenols were extracted by water extraction.The extraction process of polyphenols were optimized by single factor tests on solid-liquid ratio,extracting time and times.Old rice wine selected as the base wine was added with C.morifolium polyphenol extract,honey,citric acid and other auxiliary materials to prepare a kind of chrysanthemum old rice wine.Through sensory analysis combined with fuzzy mathematics comprehensive evaluation method,the optimal formula of chrysanthemum old rice wine was determined,and the corresponding physicochemical indicators of the obtained chrysanthemum old rice wine were tested.[Results]The optimal soaking process for C.morifolium was as follows:extraction time of 20 min,a solid-liquid ratio of C.morifolium to warm water at 1:40,extraction times of 3 times.The physical and chemical indicators of the chrysanthemum wine obtained from the above optimal formula were as follows:sugar content 5%,ethanol content 11%,and pH value 4.04.The chrysanthemum old rice wine obtained was clear and transparent,and the fragrance of chrysanthemum was coordinated with the mellow aroma of rice wine.The taste was refreshing and suitable for the vast majority of people to drink.[Conclusions]The new type of chrysanthemum old rice wine combines the polyphenolic active substances in C.morifolium with the low ethanol content of old rice wine,which not only improves the utilization rate of C.morifolium,but also strengthens the health function of old rice wine products,improves the quality of old rice wine,and promotes the healthy and rapid development of the old rice wine industry.展开更多
Long-term postprandial hyperglycemia is a primary risk factor for developing chronic metabolic diseases such as obesity,type 2 diabetes,and cardiovascular disease.Chronic hyperglycemia induces the glycation of protein...Long-term postprandial hyperglycemia is a primary risk factor for developing chronic metabolic diseases such as obesity,type 2 diabetes,and cardiovascular disease.Chronic hyperglycemia induces the glycation of proteins,oxidative stress,inflammation and increases plasma insulin and lipid concentrations.Insulin resistance is the primary cause of postprandial excursions of blood glucose and lipids.Hyperglycemia can be treated by lowering dietary carbohydrates intake,digestion,and absorption.Various functional foods improve glucose metabolism by increasing insulin sensitivity and inhibitingα-glucosidase in the small intestine.Natural phytochemicals,especially active phenolics are good antioxidants and show anti-inflammatory action and regulate blood glucose.This review aimed to report on hypoglycemic properties of active phenolics from functional foods and their proposed anti-diabetic mechanisms.Nevertheless,further clinical trials are required to confirm the bioavailability,safety,and efficacy of phenolics,especially the dosage and duration of treatment,to avoid adverse effects and give better dietary recommendations.展开更多
Tanshinone and phenolic acids are the most important active substances of Salvia miltiorrhiza,and the insight into their transcriptional regulatory mechanisms is an essential process to increase their content in vivo....Tanshinone and phenolic acids are the most important active substances of Salvia miltiorrhiza,and the insight into their transcriptional regulatory mechanisms is an essential process to increase their content in vivo.SmMYB36 has been found to have important regulatory functions in the synthesis of tanshinone and phenolic acid;paradoxically,its mechanism of action in S.miltiorrhiza is not clear.Here,we demonstrated that SmMYB36 functions as a promoter of tanshinones accumulation and a suppressor of phenolic acids through the generation of SmMYB36 overexpressed and chimeric SmMYB36-SRDX(EAR repressive domain)repressor hairy roots in combination with transcriptomic-metabolomic analysis.SmMYB36 directly down-regulate the key enzyme gene of primary metabolism,SmGAPC,up-regulate the tanshinones biosynthesis branch genes SmDXS2,SmGGPPS1,SmCPS1 and down-regulate the phenolic acids biosynthesis branch enzyme gene,SmRAS.Meanwhile,SmERF6,a positive regulator of tanshinone synthesis activating SmCPS1,was up-regulated and SmERF115,a positive regulator of phenolic acid biosynthesis activating SmRAS,was down-regulated.Furthermore,the seven acidic amino acids at the C-terminus of SmMYB36 are required for both self-activating domain and activation of target gene expression.As a consequence,this study contributes to reveal the potential relevance of transcription factors synergistically regulating the biosynthesis of tanshinone and phenolic acid.展开更多
The extraction technology of phenolic acid compounds from Salvia miltiorrhiza by ethanol reflux was studied. In this experiment, salvianolic acid B standard was used to make the standard curve. Single factor experimen...The extraction technology of phenolic acid compounds from Salvia miltiorrhiza by ethanol reflux was studied. In this experiment, salvianolic acid B standard was used to make the standard curve. Single factor experiment and orthogonal experiment were used to study the extraction of different ethanol concentrations, reflux times and material-to-liquid ratios. The OD value of salvianolic acid compounds was measured with a spectrophotometer. The extraction rate of phenolic acid compounds under different extraction conditions was calculated through a regression equation, so as to obtain the optimal conditions for the ethanol reflux extraction process of Salvia miltiorrhiza. The experimental data can provide a reference for the ethanol reflux extraction process of salvianolic acids in the industry. According to the experiment, the extraction rate of phenolic acids in Salvia miltiorrhiza was the highest when the ethanol concentration was 60%, the reflux time was 1.5 hours, and the ratio of material-to-liquid was 1:10.展开更多
The promoting effect of zirconium addition on Pd/Beta catalysts has been investigated in the selective hydrogenation of phenol to cyclohexanone in the aqueous phase. The activity of the catalyst in the reaction was gr...The promoting effect of zirconium addition on Pd/Beta catalysts has been investigated in the selective hydrogenation of phenol to cyclohexanone in the aqueous phase. The activity of the catalyst in the reaction was greatly improved by introducing Zr atoms into the framework of H-Beta zeolite. An important synergy between the Zr species and Pd, affecting the Pd dispersion state on the support, has been observed. The modification of the support with Zr^(4+) improves the Lewis/Brφnsted acid ratio of the catalyst, suppressing the further transformation of cyclohexanone. The kinetics of Pd/Zr-Beta catalyst showed high selectivity to cyclohexanone. The catalytic results showed that the Pd/Zr-Beta had the best catalytic performance at the desired temperature of 80℃ for 5 h.展开更多
A new magnetic nanocomposite chitosan/EDTA/CeZnO(MEC-CeZnO)is synthesized as an efficient and eco-friendly bio-compound for the removal of chromium Cr(VI)metal ions and phenol organic matters from aqueous solutions.Na...A new magnetic nanocomposite chitosan/EDTA/CeZnO(MEC-CeZnO)is synthesized as an efficient and eco-friendly bio-compound for the removal of chromium Cr(VI)metal ions and phenol organic matters from aqueous solutions.Nanocomposites are characterized using field emission scanning electron microscope,energy dispersive X-ray spectroscopy,transmission electron microscope,X-ray diffraction,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,diffuse reflection spectroscopy,and PL methods.The reduction rate of Cr(VI)ions and phenol degradation is evaluated under various experimental conditions,separately and simultaneously.The average pore diameter and specific surface of MEC-CeZnO nanocomposite are obtained 50 nm and 210 m^(2)·g^(-1)respectively,which suggest the successful synthesis of the nanocomposite because of the increased surface area and reduced pores in comparison to previous studies.Moreover,the best Cr(VI)and phenol reduction efficiencies are 98%and 92%at 180 min of retention time,both following the Langmuir-Hinshelwood first-order kinetics.The mechanisms of Cr(VI)and phenol removal from aqueous solutions involved Cr(VI)reduction,phenol oxidation,and adsorption.Examining the reusability of MEC-CeZnO showed that both degradation and recovery capacity is stable in 5 cycles.展开更多
Phenol in waste water threatens human health and is difficultly to be decomposed by nature.Efficient degradation of high-loaded phenol in water under mild condition is still a great challenge.Herein,ionic liquids with...Phenol in waste water threatens human health and is difficultly to be decomposed by nature.Efficient degradation of high-loaded phenol in water under mild condition is still a great challenge.Herein,ionic liquids with tungstate anion were designed and prepared.It was found that dodecyltrimethylammonium tungstate could catalyzed degradation of phenol into gases and water thoroughly at 323 k in 8 h.Tungstate anion revealed good catalytic oxidative activity and long carbon chain group connecting with cation of ionic liquids enriched phenol around catalysts,which induced the complete degradation of phenol at mild conditions.Increasing the amounts of hydrogen peroxide benefited to the total degradation of phenol.In addition,the ionic liquid could be reused for its excellent thermal stability.Our work provided a different strategy to treat waste water containing phenol efficiently.展开更多
Allelopathy is an important mechanism in Eucalyptus plantations that causes detrimental impacts on understory diversity.Phenolic compounds are the main allelochemicals suppressing understory plants.However,the dynamic...Allelopathy is an important mechanism in Eucalyptus plantations that causes detrimental impacts on understory diversity.Phenolic compounds are the main allelochemicals suppressing understory plants.However,the dynamic changes in phenolic allelochemicals and their relationship with understory diversity with increasing age of Eucalyptus plantations remain largely unclear.In this study,the understory plant diversity was assessed and phenolic compounds identified from leaf litter,roots,and rhizosphere soil samples in a Eucalyptus grandis plantation at two-year intervals for ten years using ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The abundance and diversity of under story plant species were lowest in 4-year-old plantations and increased significantly with age.Seven phenolic acids and 10 flavonoids were identified from leaf litter,roots,and rhizosphere soils.Most of the potential phenolic allelochemicals,such as salicylic acid,gallic acid,4-hydroxybenzoic acid,and epicatechin,were more abundant in younger plantations,especially at4 years old.The concentrations of phenolic compounds in the rhizosphere zone were significantly lower than in litter and root samples and did not change significantly with an increase in age.Notably,phenolic compounds contributed more to the variation in the understory plants than soil factors.Hydroxyphenyllactic acid,ellagic acid,quercetin,salicylic acid,and 4-hydroxybenzoic acid were the main phenolic compounds explaining the variation in plant diversity with plantation age.These findings indicate that young E.grandis plantations,especially at four years of age,merit a greater focus because of their lower understory plant diversity and higher allelopathic potential.展开更多
The fruits of the Sea buckthorn(Hippophae rhamnoides L.)are a popular plant food and a valuable health product.Cultivating plants produces a lot of leaves with fine branches as an unnecessary residue,which needs valor...The fruits of the Sea buckthorn(Hippophae rhamnoides L.)are a popular plant food and a valuable health product.Cultivating plants produces a lot of leaves with fine branches as an unnecessary residue,which needs valorization.The aim of the study was to estimate(by HPLC-MS/MS)the qualitative and quantitative content of polyphenolic compounds in different parts of H.rhamnoides(HR),and to determine the level of antioxidant activity of leaves and fruits(by DPPH,ABTS methods and ferrozine test).Up to 19 compounds were identified in different parts of HR.The fruits are rich in flavonoids,including various glycosides of flavonols isorhamnetin,quercetin,and kaempferol.Two isorhamnetin glycosides were not identified in the leaves,while isorhamnetin-3-rhamnosylglactosides and the ellagitannins hippophaenin B,stachyurin and casuarinin were present only in the leaves of the plant.The bark and roots contained considerably more catechins,but minimal flavonols than the fruits and leaves of HR.The total phenolics and flavonols were most abundant in water infusions from leaves of HR(especially quercetin-3-O-glucoside-7-O-rhamnoside),compared to methanolic extracts.No significant differences in the quantitative and qualitative content of the fresh and dried leaves were detected.The highest antioxidant activity by all three methods was detected in the leaves of HR.In addition to the fruits,the leaves may have a perspective as a source of biologically active substances of HR.展开更多
Internal browning(IB),a major physiological disorder of pineapples,usually happens in postharvest processes,but the underlying mechanism remains elusive.The bHLH transcription factors are involved in regulating variou...Internal browning(IB),a major physiological disorder of pineapples,usually happens in postharvest processes,but the underlying mechanism remains elusive.The bHLH transcription factors are involved in regulating various biological processes,but whether they could regulate tissue browning in fruit during storage remains unknown.Here we showed that the phenolic biosynthesis pathway was activated in pineapples showing IB following 9 days of storage.AcbHLH144 expression was the highest of the 180 transcription factors identified,downregulated in pineapple with IB,and negatively correlated with the major phenolic biosynthetic genes.AcbHLH144 was shown to be localized in the nucleus and its transient overexpression in pineapples and overexpression in Arabidopsis decreased phenolic biosynthesis.The yeast one-hybrid assay and electrophoretic mobility shift assay showed that AcbHLH144 directly bound to the Ac4CL5 promoter and the dual-luciferase reporter assay showed that it inactivated Ac4CL5 transcription.These results strongly suggest AcbHLH144 as a repressor for phenolic biosynthesis.Abscisic acid(ABA)alleviated IB,reduced phenolic accumulation,and downregulated phenolic biosynthetic genes,including Ac4CL5.Transcriptomic analysis showed that AcbHLH144 was the most upregulated of all 39 bHLHs in response to ABA.ABA enhanced AcbHLH144 expression,reduced phenolic contents,and downregulated phenolic biosynthetic genes in pineapples transiently overexpressing AcbHLH144.Moreover,ABA enhanced enzyme activity of GUS driven by the AcbHLH144 promoter.These results showed that AcbHLH144 as a repressor for phenolic biosynthesis could be activated by ABA.Collectively,the work demonstrated that AcbHLH144 negatively regulated phenolic biosynthesis via inactivating Ac4CL5 transcription to modulate pineapple IB.The findings provide novel insight into the role of AcbHLH144 in modulating pineapple IB during postharvest processes.展开更多
In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of ex...In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of excess tertiary butanol(TBA)is investigated.It is revealed that the direct reaction between ozone and phenol in the rotating packed bed(RPB)follows the pseudo-first-order kinetics with a reaction rate constant higher than that in the conventional bubbling reactor(BR).Under different conditions of temperature,initial pH,high-gravity factor,and gaseous ozone concentration,the apparent reaction rate constant varies in the range of 0.0160–0.115 min-1.An empirical power-exponential model is established to characterize the effects of these parameters on the direct reaction between ozone and phenol by high-gravity intensified heterogeneous catalytic ozonation.展开更多
The composites were prepared by modifying silicon carbide fiber with particles of zirconium carbide(ZrC)and boron carbide(B_(4)C)and incorporating them into a phenolic resin matrix.The influence of ZrC and B_(4)C on t...The composites were prepared by modifying silicon carbide fiber with particles of zirconium carbide(ZrC)and boron carbide(B_(4)C)and incorporating them into a phenolic resin matrix.The influence of ZrC and B_(4)C on the mechanical performance of SiCf/phenolic composites after high-temperature pyrolysis was studied through flexural performance test.The results show that the composite material has good thermal stability and high-temperature mechanical properties.After static ablation at 1400℃ for 15 minutes,the flexural strength of the composite material reaches 286 MPa,which is still 7.3%higher than at room temperature,indicating that the composite material still has good mechanical properties even after heat treatment at 1400℃.展开更多
Phenolics are vital for the adaptation of plants to terrestrial habitats and for species diversity.Phenoloxidases(catechol oxidases,COs,and laccases,LACs)are responsible for the oxidation and polymerization of phenoli...Phenolics are vital for the adaptation of plants to terrestrial habitats and for species diversity.Phenoloxidases(catechol oxidases,COs,and laccases,LACs)are responsible for the oxidation and polymerization of phenolics.However,their origin,evolution,and differential roles during plant development and land colonization are unclear.We performed the phylogeny,domain,amino acids,compositional biases,and intron analyses to clarify the origin and evolution of COs and LACs,and analysed the structure,selective pressure,and chloroplast targeting to understand the species-dependent distribution of COs.We found that Streptophyta COs were not homologous to the Chlorophyta tyrosinases(TYRs),and might have been acquired by horizontal gene transfer from bacteria.COs expanded in bryophytes.Structural-functionality and selective pressure were partially responsible for the species-dependent retention of COs in embryophytes.LACs emerged in Zygnemaphyceae,having evolved from ascorbate oxidases(AAOs),and prevailed in the vascular plants and strongly expanded in seed plants.COs and LACs coevolved with the phenolic metabolism pathway genes.These results suggested that TYRs and AAOs were the first-stage phenoloxidases in Chlorophyta.COs might be the second key for the early land colonization.LACs were the third one(dominating in the vascular plants)and might be advantageous for diversified phenol substrates and the erect growth of plants.This work provided new insights into how phenoloxidases evolved and were devoted to plant evolution.展开更多
基金the support from National Key Research and Development Program of China(2021YFC2104400)the Tianjin Science and Technology Plan Project(21JCQNJC00340)the Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.
基金partly supported by the National Natural Science Foundation of China(Grant Nos.22178107,U21A2060,22178116)Xinjiang Uygur Autonomous Region Key Research and Development Program(Grant No.2022B01030)Shanghai Pujiang Program(Grant No.21PJD019)。
文摘Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space missions.To improve the ablative properties,silica sol with good particle size distribution prepared using tetramethoxysilane(TMOS)was blended with natural rubber latex and deposited onto carbon fiber felt,which was then integrated with phenolic aerogel matrix,introducing nano-silica into the framework of CFPA.The modified CFPA with a low density of 0.28—0.31 g/cm3exhibits strain-in-fracture as high as 31.2%and thermal conductivity as low as 0.054 W/(m·K).Furthermore,a trace amount of nano-silica could effectively protect CFPA from erosion of oxidizing atmosphere in different high-temperature environments.The oxyacetylene ablation test of 3000°C for 20 s shows a mass ablation rate of 0.0225 g/s,a linear ablation rate of 0.209 mm/s for the modified CFPA,which are 9.64%and 24.82%lower than the unmodified one.Besides,the long-time butane ablation test of 1200°C for 200 s shows an insignificant recession with mass and linear ablation rate of 0.079 g/s and 0.039 mm/s,16.84%and 13.33%lower than the unmodified one.Meanwhile,the fixed thermocouple in the test also demonstrates a good thermal insulation performance with a low peak back-face temperature of 207.7°C,12.25%lower than the unmodified one.Therefore,the nano-silica modified CFPA with excellent overall performance presents promising prospects in high-temperature aerospace applications.
基金the National Key Research and Development Program(2021YFC3001103)the National Natural Science Foundation(22278209,22178165,21921006,22208149)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20211262,BK20220354)a project funded by the priority academic program development of Jiangsu higher education institutions(PAPD)of China。
文摘The selective hydrogenation of highly toxic phenolic compounds to generate alcohols with thermal stability,environmental friendliness,and non-toxicity is of great importance.Herein,a series of Co-based catalysts,named Co@NCNTs,were designed and constructed by direct pyrolysis of hollow ZIF-67(HZIF-67)under H_(2)/Ar atmosphere.The evolution of the catalyst surface from the shell layer assembled by ZIF-67-derived particles to the in situ-grown hollow nitrogen-doped carbon nanotubes(NCNTs)with certain length and density is achieved by adjusting the pyrolysis atmosphere and temperature.Due to the synergistic effects of in situ-formed hollow NCNTs,well-dispersed Co nanoparticles,and intact carbon matrix,the as-prepared Co@NCNTs-0.10-450 catalyst exhibits superior catalytic performance in the hydrogenation of phenolic compounds to alcohols.The turnover frequency value of Co@NCNTs-0.10-450is 3.52 h^(-1),5.9 times higher than that of Co@NCNTs-0.40-450 and 4.5 times higher than that of Co@NCNTs-0.10-550,exceeding most previously reported non-noble metal catalysts.Our findings provide new insights into the development of non-precious metal,efficient,and cost-effective metal-organic framework-derived catalysts for the hydrogenation of phenolic compounds to alcohols.
文摘The purpose of this study is to investigate the physicochemical properties of some local varieties of onion (Allium cepa L.) and compare them with an imported variety, all collected in May 2021. Proteins, reducing sugars, lipids, and polyphenol content were estimated according to the AFNOR standardized methods. The determination of calcium, magnesium, iron, sodium, potassium and phosphorus was performed by atomic absorption spectrophotometer coupled with a CCD detector. The results highlighted an average acidity of 0.377% ± 0.002% lower than the value of the imported variety which is 0.520% ± 0.001%. Local varieties have a pH ranging from 6.35 ± 0.003 to 6.42 ± 0.004, while the variety has a pH of 6.36 ± 0.003. The ash and dry matter contents vary respectively from 4.788% ± 0.004% to 8.253% ± 0.003% and 7.945% ± 0.021% to 11.945% ± 0.007% for the local varieties. Moreover, the imported one has ash and dry matter contents of 5.175% ± 0.007% and 10.035% ± 0.021% respectively. The results show that the protein, reducing sugar and lipid contents in the local onion varieties vary respectively from 2.815 ± 0.000 to 15.634 ± 0.001 g·100 g<sup>-1</sup>;4.691 ± 0.001 to 12.596 ± 0.002 g·100 g<sup>-1</sup> and 0.006 ± 0.001 to 0.050 ± 0.057 g·100 g<sup>-1</sup>. Furthermore, the imported variety has a protein, reducing sugar and lipid content of 5.649 ± 0.002;8.565 ± 0.002 g·100 g<sup>-1</sup> and 0.011 ± 0.010 g·100 g<sup>-1</sup> respectively. The maximum levels of total polyphenols are obtained in the imported variety, Bellani and Gandiol, respectively 9.973 ± 0.001, 4.535 ± 0.002, and 3.425 ± 0.006 mg EAG/g of dry matter. The local varieties have a significant calorific intake of between 35.451 ± 0.001 and 112.980 ± 0.003 kcal·100 g<sup>-1</sup> compared to the imported one with an energy value of 56.953 ± 0.001 kcal·100 g<sup>-1</sup> of dry matter. The bulbs of different onion varieties studied have a fairly high content of mineral elements. The potassium content of local varieties is between 502.16 ± 0.06 mg·100 g<sup>-1</sup> and 582.77 ± 0.04 mg·100 g<sup>-1</sup> while the imported variety has a content of 536.62 ± 1.30 mg·100 g<sup>-1</sup>. They note that the local varieties have a better calcium content (249.75 ± 0.07 to 434.20 ± 0.57 mg·100 g<sup>-1</sup>) and magnesium (142.15 ± 0.07 to 162.60 ± 0.42 mg·100 g<sup>-1</sup>) than the imported variety (229.58 ± 0.04 mg·100 g<sup>-1</sup>) except for the varieties White Grano (228.29 ± 0.01 mg·100 g<sup>-1</sup>) and Rouge Amposta (117.00 ± 0.42 mg·100 g<sup>-1</sup>) respectively. These results reveal that Gandiol, Dayo and Orient F1 are nutritionally found better due to their higher antioxidant property, proteins, carbohydrates, and reducing sugar and should be included in diets to supplement our daily allowance needed by the body.
文摘The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .
文摘Whole grains of proso and barnyard millets were sequentially extracted using different solvents(hexane,chloroform,ethyl acetate,and methanol).Phytochemical analysis was performed qualitatively,and the total phenolic content in the extracts of proso and barnyard millets was quantified.Alkaloids and cardiac glycosides were identified in all solvent extracts of both millets.Anthraquinone and glycosides yielded negative results in all solvent extracts of both millets.Among all the solvent extracts,methanol extracts of proso and barnyard millets showed the presence of major compounds such as flavonoids,terpenoids,amino acids,tannins,and phenolics compounds.The maximum amount of phenols was found in methanolic extracts of proso and barnyard millets(0.669±0.003 and 0.625±0.003),followed by the chloroform extract of proso and barnyard millets(0.284±0.002 and 0.257±0.003).The minimum amount of phenolics was found in the acetone extract of proso and barnyard millets.The methanol extract of both millets showed the presence of major compounds with high phenolic content.
基金sponsored by the National Natural Science Foundation of China(22225804)Shanghai Sailing Program,China(21YF1409500)+1 种基金the National Natural Science Foundation of China(22078102)the Education and Scientific Research Projects of Shanghai,China(19DZ1208201)。
文摘Phenolic wastewater is one of the priorities in the field of wastewater treatment,which poses a serious threat to the human health and nature environment.In this paper,cationic cetyltrimethylammonium bromide(CTAB)and anionic sodium oleate(Na OL)microemulsions were utilized to extract phenol from the wastewater.The optimal extraction factors were investigated by exploring the effects of microemulsion composition ratio and extraction conditions on the phenol extraction performance.Furthermore,the enhanced extraction mechanism of phenol by cations microemulsions is illustrated by studying the extraction process of cationic and anionic microemulsions in the extraction of phenol.The optimum components were obtained:surfactant concentration of 0.2 mol·L^(-1),isoamyl alcohol volume of 30%,internal aqueous phase concentration of CTAB microemulsion of 0.05 mol·L^(-1),and internal aqueous phase concentration of Na OL microemulsion of 0.09 mol·L^(-1).The extraction efficiencies were 96.44%and 82.0%when using CTAB and Na OL microemulsions under optimal conditions(water-emulsion ratio of 5,contact time of 9 min,extraction temperature of 298.15 K,and p H of 9),confirming the enhanced extraction of phenol by CTAB cationic microemulsion.It was analyzed that the enhanced extraction of CTAB microemulsion was due to the electrostatic adsorption of cations with phenol root ions.
文摘[Objectives]This study was conducted to provide a theoretical basis for the extraction and comprehensive utilization of functional active components of Chrysanthemum morifolium polyphenols.[Methods]With C.morifolium as a raw material,polyphenols were extracted by water extraction.The extraction process of polyphenols were optimized by single factor tests on solid-liquid ratio,extracting time and times.Old rice wine selected as the base wine was added with C.morifolium polyphenol extract,honey,citric acid and other auxiliary materials to prepare a kind of chrysanthemum old rice wine.Through sensory analysis combined with fuzzy mathematics comprehensive evaluation method,the optimal formula of chrysanthemum old rice wine was determined,and the corresponding physicochemical indicators of the obtained chrysanthemum old rice wine were tested.[Results]The optimal soaking process for C.morifolium was as follows:extraction time of 20 min,a solid-liquid ratio of C.morifolium to warm water at 1:40,extraction times of 3 times.The physical and chemical indicators of the chrysanthemum wine obtained from the above optimal formula were as follows:sugar content 5%,ethanol content 11%,and pH value 4.04.The chrysanthemum old rice wine obtained was clear and transparent,and the fragrance of chrysanthemum was coordinated with the mellow aroma of rice wine.The taste was refreshing and suitable for the vast majority of people to drink.[Conclusions]The new type of chrysanthemum old rice wine combines the polyphenolic active substances in C.morifolium with the low ethanol content of old rice wine,which not only improves the utilization rate of C.morifolium,but also strengthens the health function of old rice wine products,improves the quality of old rice wine,and promotes the healthy and rapid development of the old rice wine industry.
文摘Long-term postprandial hyperglycemia is a primary risk factor for developing chronic metabolic diseases such as obesity,type 2 diabetes,and cardiovascular disease.Chronic hyperglycemia induces the glycation of proteins,oxidative stress,inflammation and increases plasma insulin and lipid concentrations.Insulin resistance is the primary cause of postprandial excursions of blood glucose and lipids.Hyperglycemia can be treated by lowering dietary carbohydrates intake,digestion,and absorption.Various functional foods improve glucose metabolism by increasing insulin sensitivity and inhibitingα-glucosidase in the small intestine.Natural phytochemicals,especially active phenolics are good antioxidants and show anti-inflammatory action and regulate blood glucose.This review aimed to report on hypoglycemic properties of active phenolics from functional foods and their proposed anti-diabetic mechanisms.Nevertheless,further clinical trials are required to confirm the bioavailability,safety,and efficacy of phenolics,especially the dosage and duration of treatment,to avoid adverse effects and give better dietary recommendations.
基金This work was supported by the National Natural Science Foundation of China(Project No.32270278).
文摘Tanshinone and phenolic acids are the most important active substances of Salvia miltiorrhiza,and the insight into their transcriptional regulatory mechanisms is an essential process to increase their content in vivo.SmMYB36 has been found to have important regulatory functions in the synthesis of tanshinone and phenolic acid;paradoxically,its mechanism of action in S.miltiorrhiza is not clear.Here,we demonstrated that SmMYB36 functions as a promoter of tanshinones accumulation and a suppressor of phenolic acids through the generation of SmMYB36 overexpressed and chimeric SmMYB36-SRDX(EAR repressive domain)repressor hairy roots in combination with transcriptomic-metabolomic analysis.SmMYB36 directly down-regulate the key enzyme gene of primary metabolism,SmGAPC,up-regulate the tanshinones biosynthesis branch genes SmDXS2,SmGGPPS1,SmCPS1 and down-regulate the phenolic acids biosynthesis branch enzyme gene,SmRAS.Meanwhile,SmERF6,a positive regulator of tanshinone synthesis activating SmCPS1,was up-regulated and SmERF115,a positive regulator of phenolic acid biosynthesis activating SmRAS,was down-regulated.Furthermore,the seven acidic amino acids at the C-terminus of SmMYB36 are required for both self-activating domain and activation of target gene expression.As a consequence,this study contributes to reveal the potential relevance of transcription factors synergistically regulating the biosynthesis of tanshinone and phenolic acid.
文摘The extraction technology of phenolic acid compounds from Salvia miltiorrhiza by ethanol reflux was studied. In this experiment, salvianolic acid B standard was used to make the standard curve. Single factor experiment and orthogonal experiment were used to study the extraction of different ethanol concentrations, reflux times and material-to-liquid ratios. The OD value of salvianolic acid compounds was measured with a spectrophotometer. The extraction rate of phenolic acid compounds under different extraction conditions was calculated through a regression equation, so as to obtain the optimal conditions for the ethanol reflux extraction process of Salvia miltiorrhiza. The experimental data can provide a reference for the ethanol reflux extraction process of salvianolic acids in the industry. According to the experiment, the extraction rate of phenolic acids in Salvia miltiorrhiza was the highest when the ethanol concentration was 60%, the reflux time was 1.5 hours, and the ratio of material-to-liquid was 1:10.
基金Financial supports from the State Key Laboratory of Catalytic Materials and Reaction Engineering (RIPP, SINOPEC)。
文摘The promoting effect of zirconium addition on Pd/Beta catalysts has been investigated in the selective hydrogenation of phenol to cyclohexanone in the aqueous phase. The activity of the catalyst in the reaction was greatly improved by introducing Zr atoms into the framework of H-Beta zeolite. An important synergy between the Zr species and Pd, affecting the Pd dispersion state on the support, has been observed. The modification of the support with Zr^(4+) improves the Lewis/Brφnsted acid ratio of the catalyst, suppressing the further transformation of cyclohexanone. The kinetics of Pd/Zr-Beta catalyst showed high selectivity to cyclohexanone. The catalytic results showed that the Pd/Zr-Beta had the best catalytic performance at the desired temperature of 80℃ for 5 h.
文摘A new magnetic nanocomposite chitosan/EDTA/CeZnO(MEC-CeZnO)is synthesized as an efficient and eco-friendly bio-compound for the removal of chromium Cr(VI)metal ions and phenol organic matters from aqueous solutions.Nanocomposites are characterized using field emission scanning electron microscope,energy dispersive X-ray spectroscopy,transmission electron microscope,X-ray diffraction,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,diffuse reflection spectroscopy,and PL methods.The reduction rate of Cr(VI)ions and phenol degradation is evaluated under various experimental conditions,separately and simultaneously.The average pore diameter and specific surface of MEC-CeZnO nanocomposite are obtained 50 nm and 210 m^(2)·g^(-1)respectively,which suggest the successful synthesis of the nanocomposite because of the increased surface area and reduced pores in comparison to previous studies.Moreover,the best Cr(VI)and phenol reduction efficiencies are 98%and 92%at 180 min of retention time,both following the Langmuir-Hinshelwood first-order kinetics.The mechanisms of Cr(VI)and phenol removal from aqueous solutions involved Cr(VI)reduction,phenol oxidation,and adsorption.Examining the reusability of MEC-CeZnO showed that both degradation and recovery capacity is stable in 5 cycles.
基金financially supported by the National Natural Science Foundation of China(21875265,22293015,22121002)。
文摘Phenol in waste water threatens human health and is difficultly to be decomposed by nature.Efficient degradation of high-loaded phenol in water under mild condition is still a great challenge.Herein,ionic liquids with tungstate anion were designed and prepared.It was found that dodecyltrimethylammonium tungstate could catalyzed degradation of phenol into gases and water thoroughly at 323 k in 8 h.Tungstate anion revealed good catalytic oxidative activity and long carbon chain group connecting with cation of ionic liquids enriched phenol around catalysts,which induced the complete degradation of phenol at mild conditions.Increasing the amounts of hydrogen peroxide benefited to the total degradation of phenol.In addition,the ionic liquid could be reused for its excellent thermal stability.Our work provided a different strategy to treat waste water containing phenol efficiently.
基金funded by the National Nature Science Foundation of China (No.32171775,31770671)。
文摘Allelopathy is an important mechanism in Eucalyptus plantations that causes detrimental impacts on understory diversity.Phenolic compounds are the main allelochemicals suppressing understory plants.However,the dynamic changes in phenolic allelochemicals and their relationship with understory diversity with increasing age of Eucalyptus plantations remain largely unclear.In this study,the understory plant diversity was assessed and phenolic compounds identified from leaf litter,roots,and rhizosphere soil samples in a Eucalyptus grandis plantation at two-year intervals for ten years using ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).The abundance and diversity of under story plant species were lowest in 4-year-old plantations and increased significantly with age.Seven phenolic acids and 10 flavonoids were identified from leaf litter,roots,and rhizosphere soils.Most of the potential phenolic allelochemicals,such as salicylic acid,gallic acid,4-hydroxybenzoic acid,and epicatechin,were more abundant in younger plantations,especially at4 years old.The concentrations of phenolic compounds in the rhizosphere zone were significantly lower than in litter and root samples and did not change significantly with an increase in age.Notably,phenolic compounds contributed more to the variation in the understory plants than soil factors.Hydroxyphenyllactic acid,ellagic acid,quercetin,salicylic acid,and 4-hydroxybenzoic acid were the main phenolic compounds explaining the variation in plant diversity with plantation age.These findings indicate that young E.grandis plantations,especially at four years of age,merit a greater focus because of their lower understory plant diversity and higher allelopathic potential.
基金supported by the European Union in the MSCA4Ukraine project ID Number 1232466.
文摘The fruits of the Sea buckthorn(Hippophae rhamnoides L.)are a popular plant food and a valuable health product.Cultivating plants produces a lot of leaves with fine branches as an unnecessary residue,which needs valorization.The aim of the study was to estimate(by HPLC-MS/MS)the qualitative and quantitative content of polyphenolic compounds in different parts of H.rhamnoides(HR),and to determine the level of antioxidant activity of leaves and fruits(by DPPH,ABTS methods and ferrozine test).Up to 19 compounds were identified in different parts of HR.The fruits are rich in flavonoids,including various glycosides of flavonols isorhamnetin,quercetin,and kaempferol.Two isorhamnetin glycosides were not identified in the leaves,while isorhamnetin-3-rhamnosylglactosides and the ellagitannins hippophaenin B,stachyurin and casuarinin were present only in the leaves of the plant.The bark and roots contained considerably more catechins,but minimal flavonols than the fruits and leaves of HR.The total phenolics and flavonols were most abundant in water infusions from leaves of HR(especially quercetin-3-O-glucoside-7-O-rhamnoside),compared to methanolic extracts.No significant differences in the quantitative and qualitative content of the fresh and dried leaves were detected.The highest antioxidant activity by all three methods was detected in the leaves of HR.In addition to the fruits,the leaves may have a perspective as a source of biologically active substances of HR.
基金This research was supported by the Guangdong Province Science and Technology Plan Project(2016A020210077)the National Key R&D Program of China(2020YFD1000600)。
文摘Internal browning(IB),a major physiological disorder of pineapples,usually happens in postharvest processes,but the underlying mechanism remains elusive.The bHLH transcription factors are involved in regulating various biological processes,but whether they could regulate tissue browning in fruit during storage remains unknown.Here we showed that the phenolic biosynthesis pathway was activated in pineapples showing IB following 9 days of storage.AcbHLH144 expression was the highest of the 180 transcription factors identified,downregulated in pineapple with IB,and negatively correlated with the major phenolic biosynthetic genes.AcbHLH144 was shown to be localized in the nucleus and its transient overexpression in pineapples and overexpression in Arabidopsis decreased phenolic biosynthesis.The yeast one-hybrid assay and electrophoretic mobility shift assay showed that AcbHLH144 directly bound to the Ac4CL5 promoter and the dual-luciferase reporter assay showed that it inactivated Ac4CL5 transcription.These results strongly suggest AcbHLH144 as a repressor for phenolic biosynthesis.Abscisic acid(ABA)alleviated IB,reduced phenolic accumulation,and downregulated phenolic biosynthetic genes,including Ac4CL5.Transcriptomic analysis showed that AcbHLH144 was the most upregulated of all 39 bHLHs in response to ABA.ABA enhanced AcbHLH144 expression,reduced phenolic contents,and downregulated phenolic biosynthetic genes in pineapples transiently overexpressing AcbHLH144.Moreover,ABA enhanced enzyme activity of GUS driven by the AcbHLH144 promoter.These results showed that AcbHLH144 as a repressor for phenolic biosynthesis could be activated by ABA.Collectively,the work demonstrated that AcbHLH144 negatively regulated phenolic biosynthesis via inactivating Ac4CL5 transcription to modulate pineapple IB.The findings provide novel insight into the role of AcbHLH144 in modulating pineapple IB during postharvest processes.
基金supported by the Fund for Shanxi Province Higher Education“1331 Project”for Improving Quality and Efficiency Construction(nuc2021-006)Key Research&Development Plan of Shanxi Province(201903D321059)+1 种基金Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(20200004)Transformation and Cultivation Projects of Scientific and Technological Achievements in Universities of Shanxi Province Institutions(2020CG040).
文摘In this study,high-gravity intensified heterogeneous catalytic ozonation is utilized for treatment of phenol-containing wastewater,and the kinetics of the direct reaction between ozone and phenol in the presence of excess tertiary butanol(TBA)is investigated.It is revealed that the direct reaction between ozone and phenol in the rotating packed bed(RPB)follows the pseudo-first-order kinetics with a reaction rate constant higher than that in the conventional bubbling reactor(BR).Under different conditions of temperature,initial pH,high-gravity factor,and gaseous ozone concentration,the apparent reaction rate constant varies in the range of 0.0160–0.115 min-1.An empirical power-exponential model is established to characterize the effects of these parameters on the direct reaction between ozone and phenol by high-gravity intensified heterogeneous catalytic ozonation.
基金Funded by the Joint Fund of Ministry of Education for Equipment Pre-research(No.6141A02022250)the Fundamental Research Funds for the Central Universities,China(No.WUT:2021III003XZ)。
文摘The composites were prepared by modifying silicon carbide fiber with particles of zirconium carbide(ZrC)and boron carbide(B_(4)C)and incorporating them into a phenolic resin matrix.The influence of ZrC and B_(4)C on the mechanical performance of SiCf/phenolic composites after high-temperature pyrolysis was studied through flexural performance test.The results show that the composite material has good thermal stability and high-temperature mechanical properties.After static ablation at 1400℃ for 15 minutes,the flexural strength of the composite material reaches 286 MPa,which is still 7.3%higher than at room temperature,indicating that the composite material still has good mechanical properties even after heat treatment at 1400℃.
基金This work received financial support from the National Natural Science Foundation in China(Grant No.32060175 and 32060043)Fundamental Research Projects of Yunnan Province(2022530401740002).
文摘Phenolics are vital for the adaptation of plants to terrestrial habitats and for species diversity.Phenoloxidases(catechol oxidases,COs,and laccases,LACs)are responsible for the oxidation and polymerization of phenolics.However,their origin,evolution,and differential roles during plant development and land colonization are unclear.We performed the phylogeny,domain,amino acids,compositional biases,and intron analyses to clarify the origin and evolution of COs and LACs,and analysed the structure,selective pressure,and chloroplast targeting to understand the species-dependent distribution of COs.We found that Streptophyta COs were not homologous to the Chlorophyta tyrosinases(TYRs),and might have been acquired by horizontal gene transfer from bacteria.COs expanded in bryophytes.Structural-functionality and selective pressure were partially responsible for the species-dependent retention of COs in embryophytes.LACs emerged in Zygnemaphyceae,having evolved from ascorbate oxidases(AAOs),and prevailed in the vascular plants and strongly expanded in seed plants.COs and LACs coevolved with the phenolic metabolism pathway genes.These results suggested that TYRs and AAOs were the first-stage phenoloxidases in Chlorophyta.COs might be the second key for the early land colonization.LACs were the third one(dominating in the vascular plants)and might be advantageous for diversified phenol substrates and the erect growth of plants.This work provided new insights into how phenoloxidases evolved and were devoted to plant evolution.
