Hollow ZIF-67-derived Co@N-doped carbon nanotubes boosting the hydrogenation of phenolic compounds to alcohols

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.

Mechanism of action of Balanophora involucrata polyphenolic compounds in the treatment of myocardial injury based on network pharmacology and molecular docking techniques

The objective of this work was to investigate the mechanism of action of Balanophora involucrata polyphenolic compounds in the treatment of myocardial injury.In the present study,Balanophora involucrata was extracted by refluxing 75%of ethanol.The obtained extract was extracted with petroleum ether,ethyl acetate and n-butanol respectively.And the ethyl acetate layer was separated.The extract was prepared by silica gel column chromatography,sephadex LH-20 elution and thin layer chromatography.After that,the Swiss target prediction database was utilized to obtain the targets of Balanophora involucrata,and the Genecards,OMIM and TTD databases were used to predict and screen the targets of Balanophora involucrata for the treatment of myocardial injury.The active ingredient-target network was constructed using Cytoscape software,and the PPI network was mapped using String database and Cytoscape software.GO bioprocess enrichment analysis and KEGG pathway enrichment analysis were performed by Metascape software to predict the mechanism of action.Molecular docking was performed in Discovery Studio 2016 client software to verify the binding of Balanophora involucrata polyphenols to key targets.In this study,six polyphenolic compounds were isolated from Balanophora involucrata.By GO enrichment analysis,1614 biological processes(BP),127 cellular compositions(CC),and 215 molecular functions(MF)were obtained;a total of 155 cross-targets were involved in the KEGG enrichment analysis.The PPI network showed that quercetin was the main active component of polyphenolic compounds against myocardial injury and that AKT1,EGFR,STAT3,SRC,ESR1,MMP9,HSP90AA1 and other related signals were associated with myocardial injury treatment.Finally,the multi-component-multi-target-multi-pathway action of Balanophora involucrata was concluded,which provided new ideas and methods for further research on the mechanism of action of Balanophora involucrata in myocardial injury.

Effects of different thermal processing methods on bioactive components,phenolic compounds,and antioxidant activities of Qingke(highland hull-less barley)

Qingke(highland hull-less barley)is a grain replete with substantial nutrients and bioactive ingredients.In this study,we evaluated the effects of boiling(BO),steaming(ST),microwave baking(MB),far-infrared baking(FB),steam explosion(SE),and deep frying(DF)on bioactive components,phenolic compounds,and antioxidant activities of Qingke compared with the effects of traditional roast(TR).Results showed that the soluble dietary fiber,beta-glucan and water-extractable pentosans of Qingke in dry heat processes of TR,SE,MB and FB had a higher content compared with other thermal methods and had a better antioxidant activity of hydroxyl radical scavenging and a better reduction capacity,while those in wet heat processes of BO and ST had a better antioxidant activity of ABTS radical scavenging and a better Fe^(2+) chelating ability.DF-and SE-Qingke had a higher content of tocopherol,phenolic,and flavonoid.Overall,6 free phenolic compounds and 12 bound phenolic compounds of Qingke were identified,and free phenolic compounds suffered more damage during thermal processing.Principal component analysis showed that SE had more advantages in retaining and improving the main biological active ingredients of Qingke,and it may be the best method for treating Qingke.

In Vitro and in Silico Insights on the Biological Activities, Phenolic Compounds Composition of Hypericum perforatum L. Hairy Root Cultures

Three Hypericum perforatum hairy root lines(HR B,HR F and HR H)along with non-transformed roots were analyzed for phenolic compounds composition and in vitro enzyme inhibitory properties.In silico molecular modeling was performed to predict the interactions of the most representative phenolic compounds in HR clones with enzymes related to depression,neurodegeneration and diabetes.Chromatographic analyses revealed that HR clones represent an efficient source of quinic acid and hydroxybenzoic acids,epicatechin and procyanidin derivatives,quercetin and kaempferol glycosides,as well numerous xanthones.In vitro antidepressant activity of HR extracts through monoamine oxidase A(MAO-A)inhibition was attributed to the production of oxygenated and prenylated xanthones.The neuroprotective potential of HR extracts was related to the accumulation of quercetin 6-C-glucoside,epicatechin,procyanidins andγ-mangostin isomers as potential inhibitors of acetylcholinesterase(AChE)and butyrylcholinesterase(BChE).Vanillic acid and prenylated xanthones in HR clones as promising inhibitors of tyrosinase additionally contributed to the neuroprotective activity.Five preeminent xanthones in HR(γ-mangostin,mangiferin,garcinone C,garcinone E and 1,3,7-trihydroxy-6-metoxy-8-prenyl xanthone)along with the flavonol quercetin 6-C-glucoside effectively inhibitedα-amylase andα-glucosidase indicating the antidiabetic properties of HR extracts.Transgenic roots of H.perforatum can be exploited for the preparation of novel phytoproducts with multi-biological activities.

Effective anti-inflammatory phenolic compounds from dandelion:identification and mechanistic insights using UHPLC-ESI-MS/MS,fluorescence quenching and anisotropy,molecular docking and dynamics simulation

This novel study identifi es the effective anti-inflammatory phenolic compounds in dandelion and provides mechanistic insights into their interactions with receptor proteins(toll-like receptor 4,TLR4;co-receptor myeloid differentiation protein-2,MD-2)using UHPLC-ESI-MS/MS,lipopolysaccharide(LPS)-stimulated THP-1 cell line,fluorescence quenching and anisotropy,molecular docking(single ligand and multi-ligand docking)and molecular dynamics simulation.A 50%aqueous methanol extract had a greater anti-inflammatory effect and higher chicoric acid content,compared with the 100%water and 100%methanol extracts.Chicoric acid,chlorogenic acid,methylophiopogonone A,caffeic acid,gallic acid monohydrate and 4’-O-demethylbroussonin A had relatively high binding energies and contents in all extracts.Chicoric acid competed with chlorogenic acid,4’-O-demethylbroussonin A and quercetin for MD-2.Among dandelion’s phenolics,chicoric acid most effectively hindered TLR4-MD-2 complex formation,with a quenching constant of 0.62×10^(6) L/mol for MD-2 or TLR4 at 320 K,and binding energies of-6.87 and-5.97 kcal/mol,respectively,for MD-2 and TLR4.

Dual Role of Plant Phenolic Compounds as Antioxidants and Prooxidants

Natural phenolic compounds are secondary metabolites found in a wide range of plants including food crops. As many of them are known to be antioxidants and can prevent several chronic and degenerative diseases in humans, they are a part of a healthy diet. However, these antioxidants can act as prooxidants under high phenolic concentration, high pH, or in the presence of transition metal ions such as Cu2+ or Fe3+, producing reactive oxygen species (ROS) including hydroxyl radicals resulting in oxidative stress and cell toxicity. While this can lead to pathogenesis including the development of various types of cancers, elevated levels of ROS are beneficial to kill malignant cells and foodborne pathogens to improve food safety. Thus, the dual nature of phenolic compounds allows them to act as antioxidants and prooxidants. Similarly, depending on the level of prooxidant activity, ROS can induce either pathogenesis or serve as a potential agent to kill malignant cells and foodborne pathogens.

Effect of pressure cooking on phenolic compounds of quinoa

Due to good nutritional properties and potential health benefits,quinoa has gained an increasing attention.The study aimed to analyze the effect of pressure cooking on the composition,antioxidant activity,antibacterial activity and bioavailability of phenolic compounds in four types of quinoa,and to evaluate the correlation between phenolics and its biological activities by correlation analysis.The results showed that different varieties of quinoa contained different phenolic components and their biological activities were different.Pressure cooking could significantly increase(P<0.05)the phenolic contents of quinoa,and decrease in vitro digestibility of protein.The antioxidant activity,antibacterial activity and bioavailability of quinoa were also enhanced which were positively related with phenolic contents.HPLC analysis indicated that at least twelve phenolic compounds were found in quinoa,and hyperoside,sinapic acid,rutin and ferulic acid occupied a majority of them.Correlation analysis suggested that hyperoside,quercetin,sinapic acid,ferulic acid and gallic acid made the key contribution to antioxidant and antibacterial activities of phenolic compounds of quinoa.The results provided valuable information for quinoa processing with phenolics as functional ingredient.

Adsorption of phenolic compounds from aqueous solutions by aminated hypercrosslinked polymers

Two novel polymers （NJ-1 and N J-2） were synthesized by chemically modified a hypercrosslinked polymer NJ-0 with dimethylamine and trimethylamine, respectively. The comparison of the adsorption properties of the three polymers toward phenol, resorcin and phloroglucin was made. The study focused on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Freundlich equation was found to fit the adsorption results well. The effect of amino groups introduced onto the surface of the resin and the structure of phenolic compounds on the adsorption were also studied. The hydrogen-bonding interaction and electrostatic interaction could happen between the amino groups and the adsorbates. The adsorption impetus increased as quantity of hydroxyl groups increased, but the adsorption capacity decreased due to the drop of the matching degree of the aperture of resins and the diameter of adsorbate molecules.

Phenolic compounds and its antioxidant activities in ethanolic extracts from seven cultivars of Chinese jujube

Phenolic compounds and its antioxidant activity of extracts from seven cultivars of Chinese jujubes were investigated by high performance liquid chromatography(HPLC)with standards and different antioxidant evaluation methods,such as phosphomolybdenum assay,superoxide radical scavenging activity(SRSA),hydroxyl radical scavenging activity(HRSA),antihemolytic activity and inhibition of lipid peroxidation in rat liver homogenate,respectively.The results showed the components of the extracts are comprised of total phenols and flavonoids,and its content ranges from 454.3 to 1298.9(GAE mg/100 g dry weight).Phlorizin,catechin,gallic acid,chlorogenic acid,caffeic acid were the predominant phenolic compounds.All the extracts had significant antioxidant activities either in vitro or in vivo.Correlation analysis indicated that the antioxidant capacities of Chinese jujube extracts demonstrated a good positive relationship with some phenolic acids,which was higher in Xiao and Goutou.The results indicated that Xiao and Goutou could be attributed to a potential source of natural antioxidants for food applications.

Phenolic compounds as natural feed additives in poultry and swine diets:a review

Due to ban on using antibiotics in feed industry,awareness of using natural feed additives have led to a great demand.The interest of plants phenolic compounds as a potential natural antioxidant source has been considered in research community due to their predictable potential role as feed additives in poultry and swine production.However,the mode of action for their functional role and dosage recommendation in animal diets are still remain indistinct.Taking into account,the present review study highlights an outline about the mode of action of phenolic compound and their experimental uses in poultry and swine focusing on the growth performance,antioxidant function,immune function,antimicrobial role and overall health status,justified with the past findings till to date.Finally,the present review study concluded that supplementation of phenolic compounds as natural feed additives may have a role on the antioxidant,immunity,antimicrobial and overall production performance in poultry and swine.

ADSORPTION BEHAVIOR OF PHENOLIC COMPOUNDS ONTO POLYMERIC ADSORBENTS MODIFIED WITH 2-CARBOXYBENZOYL GROUPS

Two hypercrosslinked polymeric adsorbents （ZH-01 and Amberlite XAD-4 resin） were employed to remove three kinds of phenolic compounds including phenol, 4-nitrophenol and 2,4-dinitrophenol from aqueous solutions. The study was focused on the static equilibrium adsorption behavior, the column dynamic adsorption and desorption profiles. The Freundlich model gave a perfect fitting to the isotherm data. The adsorbing capacities for these three compounds on ZH-01 were higher than those on Amberlite XAD-4 within the temperature range 288-318 K, which was attributed to the large micropore area and 2-carboxybenzoyl functional groups on the network of ZH-01 resin. The adsorption for phenol and 4- nitrophenol on ZH-01 was a physical adsorption process, while for 2,4-dinitrophenol it was a coexistence process of physical adsorption and chemisorption＇s transitions. The column test showed the advantages of ZH-01 in the dynamic adsorption processes of phenolic compounds. Being used as the desorption reagent, sodium hydroxide solution showed an excellent performance.

Changes of microbial community structures and functional genes during biodegradation of phenolic compounds under high salt condition

The changes of microbial community structures and functional genes during the biodegradation of single phenol and phenol plus p-cresol under high salt condition were explored.It was found that the phenol-fed system（PFS） exhibited stronger degrading abilities and more stable biomass than that of the phenol plus p-cresol-fed system（PCFS）.The microbial community structures were revealed by a modern DNA fingerprint technique,ribosomal intergenic spacer analysis（RISA）.The results indicated that the microbial community of PFS changed obviously when gradually increased phenol concentration,while PCFS showed a little change.16S rRNA sequence analysis of the major bands showed that Alcanivorax sp.genus was predominant species during phenolic compounds degradation.Furthermore,amplified functional DNA restriction analysis（AFDRA） on phenol hydroxylase genes showed that the fingerprints were substantially different in the two systems,and the fingerprints were not the same during the different operational periods.

Enhanced photodegradation of phenolic compounds by adding TiO_2 to soil in a rotary reactor

Photodegradation ofpentachlorophenol （PCP） and p-nitrophenol （PNP） in soil was carried out in a designed rotary reactor, which can provide the soil particles with continually uniform irradiation, and on a series of thin soil layers. TiO2, as a kind of environmental friendly photocatalyst, was introduced to the soil to enhance the processes. Compared with that on the soil layers, photodegradation of PCP at initial concentration of 60 mg/kg was improved dramatically in the rotary reactor no matter whether TiO2 was added, with an increase of 3.0 times in the apparent first-order rate constants. The addition of 1 wt% TiO2 furthered the improvement by 1.4 times. Without addition of TiO2, PNP （initial concentration of 60 mg/kg） photodegradation rate in the rotary reactor was similar to that on the soil layers. When 1 wt% additional TiO2 was added, PNP photodegradation was enhanced obviously, and the enhancement in the rotary reactor was 2 times of that on the soil layers, which may be attributed to the higher frequency of the contact between PNP on soil particles and the photocatalyst. The effect of soil pH and initial concentrations of the target compounds on the photodegradation in the rotary reactor was investigated. The order of the degradation rate at different soil pH was relative to the aggregation of soil particles during mixing in the rotary reactor. Photodegradation of PCP and PNP at different initial concentrations showed that addition of TiO2 to enhance the photodegradation was more suitable for contaminated soil with higher concentration of PCP, while was effective for contaminated soil at each PNP concentration tested in our study.

Glycoalkaloids and phenolic compounds in three commercial potato cultivars grown in Hebei,China

In order to investigate the food nutrition and safety of potato,the objective of the present study is to quantify glycoalkaloids(-chaconine and-solanine)and phenolic compounds in three potato cultivars,namely,Russet Burbank,Atlantic,and Shepody,grown in Hebei,China,and these two classes of biologically active compounds in commercial dehydrated potato flakes were also investigated.The total glycoalkaloid levels in whole potatoes ranged from 4.72 mg/kg for Shepody potatoes to 34.45 mg/kg for Russet Burbank potatoes.The ratio of-chaconine to-solanine in whole potatoes ranged from 0.41 for Russet Burbank potatoes to 3.61 for Atlantic potatoes.The removal rate of total glycoalkaloids in Russet Burbank potatoes during dehydrated potato flake processing is 90.0%.Chlorogenic acid is the dominant phenolic compound in Russet Burbank potatoes.By contrast,Atlantic and Shepody potatoes contain considerable caffeic acid.The loss rate of phenolic compounds in Russet Burbank during dehydrated potato flake processing is 50.47%.

Stability of phenolic compounds and drying characteristics of apple peel as affected by three drying treatments

To realize high-value utilization of discarded apple peel,this study investigated the effects of three selected commercial drying methods on drying kinetics,microstructure,color,phenolic stability and antioxidant capacity of apple peel.Apple peel was dehydrated by hot air drying(AD)at 75,65 and 55℃,heat pump drying(HP)at 65,55 and 45℃,and vacuum freeze-drying(FD),respectively.The results showed that HP was superior to AD and FD in terms of drying rate.In addition,HP at 65℃provided high-quality dried apple peel due to less browning and brighter appearance,the highest retention of total phenolics(29.35 mg/g)and the strongest antioxidant activities,with the highest ABTS and FRAP value of 127.15 and 219.57μmol TE/g,respectively.The content of the six major individual phenolics,i.e.caffeic acid,(-)-epicatechin,hyperoside,rutin,phlorizin and quercitrin,were found to be the highest in HP dried samples.Interestingly,the content of rutin was even increased after HP compared to the fresh sample.Considering drying efficiency,organoleptic quality and phenolic stability of the products,HP at 65°C is suggested for drying of apple peel.

Tailoring polymeric composite gel beads-encapsulated microorganism for efficient degradation of phenolic compounds

Phenol and its derivatives are highly toxic pollutants in industrial wastewater for the ecological environments,so there is essential attention to develop effective means of removing these harmful substances from water.In this work,the microorganism was immobilized into polymeric composite gel beads prepared by the effective recombination of natural abundant chitosan(CS)and industrial polyvinyl alcohol(PVA)for treating phenolic compounds.The degradation rate of 99.5%can be achieved to treat 100 mg·L^(1)of phenol at 30℃using the fresh resultant immobilized microorganism,where only 21.1%degradation rate was obtained by the free microorganism under the identical conditions.The recycling experiments of repeated 90 times to treat 100 mg·L^(1)of phenol displayed that the degradation rate of phenol was stable to 99%with the appearance of beads unchanged significantly,indicating the immobilized microorganism possessed excellent operating stability.Moreover,while the phenol derivatives of 100 mg·L^(1)were treated catalytically including pmethylphenol,catechol,and oaminophenol for 24 h by the immobilized microorganism,the degradation rates were all above 95%.The immobilized microorganism into PVACS polymeric composite with excellent operating stability and degradation activity would provide a feasible solution for treating phenolic compounds in water in industrial applications.

Identification of Phenolic Compounds from K.ivorensis by Selected Chromatographic and Spectrometric Techniques

A complementary approach using Liquid Chromatographic-Mass Spectrometric analysis was proposed to characterize phenolic compounds from the methanol-water extracts of K.ivorensis A.Chev.Two High Performance Liquid Chromatography(HPLC)complementary methods were used for the determination of phenolic compounds from the bark,sapwood and heartwood of K.ivorensis.Methods employed involved direct analysis after filtration at 0.20μm,using a RP C18 column and UV-VIS/ESI-FTMS detection.The methods used were different by their elution gradient and allowed analyzing the chemical composition of three parts of African mahogany extracts.In this study,22 phenolic compounds and derivatives from K.ivorensis were separated,determined or tentatively characterized for the first time based on their methanol/water/formic acid extract mass spectra.The difference of gradients eluted various compounds,8 were obtained with the first method and 14 with the second one.The main products were hydroxybenzoic acid and derivatives,resorcinol,esterified compounds,mannitol,quercetin and derivatives,dihydroxyflavan,and trihydroxyflavan.

Recent advances in microbial production of phenolic compounds

Phenolic compounds(PCs)are a group of compounds with various applications in nutraceutical,pharmaceutical and cosmetic industries.Their supply by plant extraction and chemical synthesis is often limited by low yield and high cost.Microbial production represents as a promising alternative for efficient and sustainable production of PCs.In this review,we summarize recent advances in this field,which include enzyme mining and engineering to construct artificial pathways,balance of enzyme expression to improve pathway efficiency,coculture engineering to alleviate metabolic burden and side-reactions,and the use of genetic circuits for dynamic regulation and high throughput screening.Finally,current challenges and future perspectives for efficient production of PCs are also discussed.

Composition of phenolic compounds in wastewater from the fixed-bed gasification of Baishihu coal

Crude phenols extracted using organic solvent from the wastewater of a typical fixed-bed gasification process was used as a raw material,and the distillation range was analyzed.The wide and narrow fractions of the raw material derived from distillation range analysis were cut using a real boiling point distillation device.The phenolic compounds in the different fractions were then qualitatively and quantitatively analyzed by gas chromatography after derivatization pretreatment.The yield of the<290℃fraction was 68.50%(mass fraction).A total of 33 effective phenolic compounds were identified in this fraction,and the percentage of identified phenols was nearly 80%.The contents of eight phenolic compounds were high,with phenol being the most abundant(26.34%)followed by catechol(13.44%).The contents of the remaining six abundant phenols ranged from 4%to 8%.The sum of the contents of m-cresol and p-cresol exceeded 12%,and the content of 5-indenol was nearly 8%.The yield of the fraction rich in low-grade phenols(<230℃)was 35.40%.The content of phenol in this fraction was more than 40%,the total content of cresol was over 23%,and the total content of m-cresol and p-cresol was nearly 20%.At room temperature,the 235-245℃and 245-260℃fractions were white crystals in which the catechol content was approximately 50%,and the 5-indenol content was more than 10%.The contents of these two high-value-added phenolic compounds are low in typical coal tar,making them difficult to extract.However,due to their strong polarity and good water solubility,catechol and 5-indenol are enriched in gasification wastewater by water selection,allowing their further extraction.

DFT Studies on the Antiradical Potential of Phenolic Compounds

Phenolic compounds are a class of hazardous substances for human.To study the antiradical potential of a series of phenolic compounds from the aspect of position and substituent type,phenol,o⁃dihydroxybenzene(ODB),m⁃dihydroxybenzene(MDB),p⁃dihydroxybenzene(PDB),paranitrophenol(PNP),and o⁃chlorophenol(OCP)were selected as typical targets.In addition,to elucidate the degradation discrepancy of phenolic compounds,quantum chemical calculations(QCCs)were obtained using the B3LYP method along with a 6-311G(d,p)basis set.Calculations indicate that phenol,ODB,MDB,and PDB,with electron⁃donating groups,exhibited high antiradical potential,while PNP and OCP,with electron⁃withdrawing groups,exhibited low antiradical potential.The chemical indices calculations show that para⁃compounds and ortho⁃compounds had high antiradical ability.Moreover,phenol,ODB,MDB,and PDB possessed higher bond dissociation enthalpy(BDE)and lower adiabatic ionization potential(AIP)values compared with those of OCP and PNP.Medium effects,even in vacuo,were also taken into account to reveal the antiradical ability of phenolic compounds.