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1
Shi, Zhen Jing, Meng Xiang Fang, Chun Guang Zhou, Shu Rong Wang, and Zhong Yang Luo. "Studies on the Extraction of Phenols from Coal Tar Produced in Multi-Generation System." Advanced Materials Research 347-353 (October 2011): 673–77. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.673.
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Isolation of phenols from the middle oil fraction(170-230°C) of tar produced in the multi-cogeneration system has been investigated for the purpose of recovering valuable pure phenols, such as phenol, cresols, xylenol and ethyl-phenol. Phenolic compounds were separated from the middle oil by liquid-liquid extraction using alkali and sulfuric acid. The yield of phenolic fraction from the middle oil (170-230°C) is up to 37%, which is much higher compared with those of metallurgical coke plants. Chromatography-mass spectrometry was used to analyse phenolic compounds. The result shows that the phenol content is less than 2%, and main compounds are cresol(14%), xylenol(20%) . Phenols of the middle oil fraction(230-280°C) was also analysed, which main contain methyl naphthol(20%).
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Malenica, Mladenka, Magdalena Biesaga, Sandra Pedisić, and Lara Saftić Martinović. "Stability of Propolis Phenolics during Ultrasound-Assisted Extraction Procedures." Foods 13, no. 13 (June 26, 2024): 2020. http://dx.doi.org/10.3390/foods13132020.
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Propolis has gained popularity in recent years as a potential preventive and therapeutic agent due to its numerous health benefits, which include immune system boosting, blood pressure lowering, allergy treatment, and skin disease treatment. The pharmacological activity of propolis is primarily attributed to phenolics and their interactions with other compounds. Given that phenols account for most of propolis’s biological activity, various extraction methods are being developed. The resin–wax composition of the propolis matrix necessitates the development of an extraction procedure capable of breaking matrix–phenol bonds while maintaining phenol stability. Therefore, the aim of this study was to assess the stability of two major groups of phenolic compounds, flavonoids and phenolic acids, in propolis methanol/water 50/50 (v/v) extracts obtained after ultrasound-assisted extraction (USE) under different extraction parameters (extraction time and pH) and heat reflux extraction (HRE). The methodology involved varying the USE parameters, including extraction time (5, 10, and 15 min) and pH (2 and 7), followed by analysis using liquid chromatography–tandem mass spectrometry (LC-MS/MS) to quantify phenolic recoveries. Results revealed that benzoic acid and chlorogenic acid derivatives demonstrated excellent stability across all ultrasound extraction procedures. The recoveries of flavonoids were highly diverse, with luteolin, quercitrin, and hesperetin being the most stable. Overall, neutral pH improved flavonoid recovery, whereas phenolic acids remained more stable at pH = 2. The most important optimization parameter was USE time, and it was discovered that 15 min of ultrasound resulted in the best recoveries for most of the phenols tested, implying that phenols bind strongly to the propolis matrix and require ultrasound to break the bond. However, the high variability in phenol extraction and recovery after spiking the propolis sample shows that no single extraction method can produce the highest yield of all phenols tested. As a result, when working with a complex matrix like propolis, the extraction techniques and procedures for each phenol need to be optimized.
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Helal, Ahmed, Stephane Desobry, Sylvie Banon, and Sherif M. Shamsia. "Antioxidant activity and bioaccessibility of phenols-enriched edible casein/caseinate coatings during in vitro digestion." Journal of Dairy Research 82, no. 1 (October 20, 2014): 56–63. http://dx.doi.org/10.1017/s0022029914000557.
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Active films were developed for food coating applications. Entrapped phenol susceptibility to digestion was studied. Sodium caseinate (Na-CN) coatings were formulated with 0, 10, 20% Casein (CN) incorporating selected phenols as model antioxidants. This study investigated phenol/CN/Na-CN interactions, in vitro bioaccessibility of phenols and CN role in phenols retention during in vitro gastric and pancreatic digestion. The antioxidant activity of catechin (CAT), rutin (RUT), chlorogenic acid (CHL), gallic acid (GAL), and tannic acid (TA) in coatings varied with the phenolic compound type and CN concentration and was related to phenol hydrophobic binding to CN. ABTS method gave activities ranged from 412 down to 213, and DPPH method gave values from 291·7 to 190·9. An inverse relationship was found with CN content due to CN/phenol interaction. During digestion, a part of phenols was degraded by alkaline pH of pancreatic fluid. Simultaneously, CN proteolysis led to release of phenols and the bioaccessibility index remained above 80% for all phenols. The results suggested the possibility of protecting phenols against oxidation and digestive alteration by entrapment in CN and Na-CN coating films. These positive results showed the ability to produce antioxidant-enriched edible coatings to increase food protection and phenol nutritional intake.
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Brezani, Viliam, Karel Smejkal, Jan Hosek, and Veronika Tomasova. "Anti-inflammatory Natural Prenylated Phenolic Compounds - Potential Lead Substances." Current Medicinal Chemistry 25, no. 10 (April 9, 2018): 1094–159. http://dx.doi.org/10.2174/0929867324666170810161157.
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Background: Natural phenolics are secondary plant metabolites, which can be divided into several categories with the common structural feature of phenolic hydroxyl. The biological activity of phenolics is often modified and enhanced by prenylation by prenyl and geranyl; higher terpenoid chains are rare. The type of prenyl connection and modification affects their biological activity. Objective: This review summarizes information about prenylated phenols and some of their potential sources, and provides an overview of their anti-inflammatory potential in vitro and in vivo. Method: The literature search was performed using SciFinder and keywords prenyl, phenol, and inflammation. For individual compounds, an additional search was performed to find information about further activities and mechanisms of effects. Result: We summarized the effects of prenylated phenolics in vitro in cellular or biochemical systems on the production and release of inflammation-related cytokines; their effects on inhibition of cyclooxygenases and lipoxygenases; the effects on production of nitric oxide, antiradical and antioxidant activity; and the effect on the inhibition of the release of enzymes and mediators from neutrophils, mast cells and macrophages. The information about the antiphlogistic potential of prenylated phenolics is further supported by a review of their action in animal models. Conclusion: Almost 400 prenylated phenols were reviewed to overview their antiinflammatory effect. The bioactivity of several prenylated phenols was confirmed also using in vivo assays. A pool of natural prenylated phenols represents a source of inspiration for synthesis, and prenylated phenols as components of various medicinal plants used to combat inflammation could be their active principles.
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Ezerskis, Z., and Z. Jusys. "Oxidation of chlorophenols on Pt electrode in alkaline solution studied by cyclic voltammetry, galvanostatic electrolysis, and gas chromatographymass spectrometry." Pure and Applied Chemistry 73, no. 12 (January 1, 2001): 1929–40. http://dx.doi.org/10.1351/pac200173121929.
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Potentiodynamic investigations on a platinum electrode show that oxidation of phenol, monochlorophenols, dichlorophenols, 2,3,6-, 2,4,5-, 2,4,6-trichlorophenols, and pentachlorophenol in 1 M NaOH solution, containing 1 mM of phenols, proceeds in the potential region of Pt oxide formation. The oxidation rate of phenols decreases with the increase in the number of chlorine atoms in the benzene ring in the row: phenol > monochlorophenols > dichlorophenols > trichlorophenols > pentachlorophenol. The electrochemical stability of phenols, as studied using a cyclic voltammetry, depends on their chlorination degree and isomerism. Galvanostatic oxidation of 1 M NaOH solutions containing 1 mM of phenol, monochlorophenols, dichlorophenols, 2,3,6-, 2,4,5-, 2,4,6-trichlorophenols, and pentachlorophenol were carried out on a platinum electrode using 30 mA cm2 current density. The electrolysis of the solutions was performed in the course of 10 h, and concentration of phenols in the anolytes was monitored during oxidation. The concentration of phenolic compounds diminishes from 1 mM to 1050 mM during 45 h of electrooxidation and does not change during further galvanostatic oxidation. A decrease in concentration of phenols during galvanostatic electrolysis weakly depends on the isomerism and a chlorination degree of the compounds. A rapid decrease in concentration of studied phenols during the first 45 h of electrolysis and a nonselective oxidation of different chlorophenols suggest that the oxidation proceeds via electrochemically generated oxidants. Further decrease in concentration of phenols is rather small due to deactivation of the electrode as a result of polymerization of corresponding phenols and diffusion limitations.
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B.M, Dr Khalid, and Afreen Banu. "SPECTROPHOTOMETRIC DETERMINATION OF TOTAL PHENOLIC CONTENT IN AMALAKI, ASHWAGANDHA, LAKSHMAN PHAL." Avishkara 01, no. 04 (2022): 17–20. http://dx.doi.org/10.56804/avishkara.2022.1404.
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Introduction: Amalaki, Ashwaghandha and Lakshmanphal are the three common rejuvenating drugs which has been used treatment, due to its high phenols and antioxidant activity hence study conducted the analysis total phenols content in above samples. Materials & Methods: Aims & Objectives: Estimation of total phenolic content, Study setting: ACRL Laboratory SJGAMC&H Koppal. Total phenolic content using UV Visible spectrophotometer the amounts of phenols were determined by Folin Ciocalteau reagent method, Gallic acid is used as standard and total phenols were expressed as mg/g equivalent to Gallic acid. Results & Discussion: The value obtained for Amalaki is 275.57 mg of GA/g equivalent, Ashwagandha is 210.89 mg of GA/g equivalent, Lakshmanphal 73.05 mg of GA/g equivalent Conclusion: Amalaki shown high total phenol content in all three samples, Ashwagandha, Lakshmanphal also rich source of phenols and justifies their use for health benefits.
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Zhu, Lei, Chuan Zhan, Xinchu Yu, Xixi Hu, Sibo Gao, Yanqing Zang, Di Yao, Changyuan Wang, and Jingyu Xu. "Extractions, Contents, Antioxidant Activities and Compositions of Free and Bound Phenols from Kidney Bean Seeds Represented by ‘Yikeshu’ Cultivar in Cold Region." Foods 13, no. 11 (May 29, 2024): 1704. http://dx.doi.org/10.3390/foods13111704.
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To thoroughly understand the profile of phenolic phytochemicals in kidney bean seeds cultivated in a cold region, the extractions, contents, antioxidant activities, compositions of free and bound phenols in the seed coat and cotyledon, and also relevant color attributes, were investigated. The results indicated that ultrasound-assisted extraction was an efficient method for free phenols. The bound phenols in seed coat and cotyledon were released more efficiently by alkali-acid and acid-alkali sequential hydrolysis, respectively. Under the optimized extractions, total phenols (TPC), flavonoids (TFC), and anthocyanins (TAC) ranged in 7.81–32.89 mg GAE/g dw, 3.23–15.65 mg RE/g dw, and 0–0.21 mg CE/g dw in the whole seeds of the five common kidney beans. There was a big difference in phenolic distribution between red and white seeds. From whole seed, the phenols in the four red cultivars mainly existed in free state (78.84%) and seed coat (71.56%), while the phenols in the white ‘Sark’ divided equally between free (51.18%) and bound (48.82%) states and consisted chiefly in cotyledon (81.58%). The correlation analyses showed that the antioxidant activities were significantly and positively correlated with TPC and TFC. The phenolic attributes were closely associated with the color of the seed coat. Red seeds had higher total contents of phenols than white seeds. TAC had a positively significant correlation with redness. Brightness and yellowness showed a negatively significant correlation with TPC, TFC, and antioxidant capacities, which were necessarily linked with redness degree and spot in red seeds. The spotted red ‘Yikeshu’ with the most outstanding performance on phenolic attributes was selected to analyze phenolic compounds with UHPLC-QE-MS. Among the 85 identified phenolics, 2 phenolic acids and 10 flavonoids were dominant. The characteristic phenolics in free and bound states were screened in both seed coat and cotyledon, respectively. The available information on the phenolic profile may expand the utilization of kidney beans as a nutritional ingredient in the food industry.
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Muráriková, A., K. Kaffková, S. Raab, and J. Neugebauerová. "Evaluation of content of phenolics in Salvia species cultivated in South Moravian Region / Hodnotenie obsahu fenolov vo vybraných druhoch rodu Salvia L. pestovaných v Juhomoravskom kraji." Acta Facultatis Pharmaceuticae Universitatis Comenianae 62, s9 (June 1, 2015): 18–22. http://dx.doi.org/10.1515/afpuc-2015-0007.
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Abstract In this study, total phenolic content (TPC) and rosmarinic acid (RA) of 37 samples sage (Salvia L.) of extracts were determined using spectrophotometric methods. The amount of total phenols was analysed with Folin-Ciocalteu reagents. Gallic acid was used as a standard compound and the total phenols were expressed as mg.g−1 gallic acid equivalents of dried plant material. The values of the extracts displayed substantial differences. All of the investigated species except Salvia jurisicii (990.79 mg GAE. g−1 d.w.) exhibited higher content of phenolics. Among the studies, species demonstrated the highest content of phenol, followed in sequence by Salvia tomentosa, Salvia fruticosa, Salvia triloba, Salvia officinalis ‘Extrakta’, Salvia officinalis. TPC varied from 990.79 to 4459.88 mg GAE. g−1 d.w. in the extracts. The total amount of RA was between 0.88 and 8.04% among species. Salvia tomentosa, Salvia verticillata and Salvia officinalis ‘Extrakta’ had the highest content of RA. The high content of phenolic compounds indicated that these compounds contribute to the antioxidant activity.
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Abraham Sisein Eboh, Faith Owabhel Robert, and Wodu Ebizimor. "Phenolics and phytochemicals in methanolic extract of Peperomia pellucidia quantified by HPLC." Open Access Research Journal of Life Sciences 3, no. 2 (June 30, 2022): 059–62. http://dx.doi.org/10.53022/oarjls.2022.3.2.0045.
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Phenolics are compounds that contributed greatly to the healing potentials of many herbs, spices and plants of which Peperomia pellucidia is inclusive. This research aimed at determining the various phenolics present in the methanolic extract of Peperomia pellucidia extract. High performance liquid chromatography was used to analyse the phenolic content in Peperomia pellucidia extract. The result showed the presence of phenols and flavonoid quantified as total phenol 12.78 ± 2.70 mg GAE/g dry extract and total flavonoid as 10.97 ± 0.00 mg QE/g dry extract. HPLC result reveals the following phenols p-coumaric acid 32.76 mg/100g, gallic acid with a concentration of 138.07 mg/100 g. caffeic acid and naringenin were also detected in larger concentration as showed in the table. Ferulic acid, syringic acid and quercetin each has a retention time of 17.09, 17.47 and 22.60 min, a percentage area of 136.77, 96.93 and 91.06 while the concentrations where 16.129 mg/100g, 17.688 and 75.56 mg/100g respectively. Other phenolics with much higher quantity are rosmarinic acid and chlorogenic acid with retention time 23.97 and 25.06, a percentage area of 94.44 and 24.48, while the amounts quantified in Peperomia pellucidia extract was 19.133 mg/100g and 28.865 mg/100g. In conclusion methanolic extract of Peperomia pellucidia showed a lot of phenols that are very useful in the alleviation of stress that is linked with many diseases.
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Rodríguez-Romero, Manuela, Alejandro Gallardo, and Fernando Pulido. "Geographical and within-population variation of constitutive chemical defences in a Mediterranean oak (Quercus ilex)." Forest Systems 29, no. 2 (August 10, 2020): e011. http://dx.doi.org/10.5424/fs/2020292-16943.
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Aim of study: to assess whether constitutive levels of total phenols and condensed tannins acting as chemical defences in Quercus ilex vary across regions, populations and genotypes.Area of study: acorns from six Spanish regions with natural presence of Q. ilex were collected for later sowing in the greenhouse of the University of Extremadura at Plasencia, western Spain.Materials and methods: 1176 acorns from 12 populations (2 per region) were sown according to a nested design (6 regions x 2 populations/region x 7 genotypes/population). After five months, 588 emerged seedlings were harvested for phenol extraction from their leaves. Quantification of total phenols through the Folin-Ciocalteu method and condensed tannins by Porter's reagent method was carried out.Main results: total phenolics and condensed tannins correlated positively. Significant differences were found for the concentration of total phenolics and condensed tannins among regions and among genotypes, but not among populations within regions. The lowest levels of constitutive defences were found in the northern Iberian Peninsula. Also, the defensive phenolic content was significantly higher in regions with acidic soils. Heritability values (total phenols 0.37±0.08 and condensed tannins 0.48±0.36) were lower than those obtained of total tannins in a previous study.Research highlights: constitutive levels of heritable chemical defences in holm oak significantly depend on their geographical origin and genotype.Keywords: condensed tannins, genetic and latitudinal variability, heritability, total phenolics.
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Vasilakopoulou, Paraskevi B., Aimilia-Tatiana Gousgouni, Amalia E. Yanni, Nikolaos Kostomitsopoulos, Vaios T. Karathanos, and Antonia Chiou. "Polar Phenol Detection in Plasma and Serum: Insights on Sample Pre-Treatment for LC/MS Analysis and Application on the Serum of Corinthian Currant-Fed Rats." Biomolecules 12, no. 12 (December 8, 2022): 1838. http://dx.doi.org/10.3390/biom12121838.
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Analysis of plasma and serum provides valuable information on the amounts of polar phenols’ circulating after ingestion. In the present study, protein precipitation (PPT), liquid–liquid extraction (LLE), solid phase extraction (SPE), enzymatic hydrolysis and their combinations were meticulously evaluated for the extraction of a variety of polar phenolic moieties from plasma and serum. The recovery values of the above methods were compared; satisfactory recoveries (>60%) were attained for most analytes. Polar phenol aglycones undergo degradation with enzymatic hydrolysis; however, their extended phase II metabolism makes enzymatic hydrolysis a mandated process for their analysis in such biofluids. Hence, enzymatic hydrolysis followed by LLE was used for the identification of polar phenols in rats’ serum, after the long-term oral consumption of Corinthian Currant. Corinthian Currant is a Greek dried vine product rich in bioactive polar phenolics. Flavonoids and phenolic acids, detected as aglycones, ranged from 0.57 ± 0.08 to 181.66 ± 48.95 and 3.45 ± 1.20 to 897.81 ± 173.96 ng/mL, respectively. The majority of polar phenolics were present as phase II metabolites, representing their fasting state in the blood stream. This is the first study evaluating the presence of polar phenolics in the serum of rats following a long-term diet supplemented with Corinthian Currant as a whole food.
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van Gorsel, Hendrik, and Adel A. Kader. "PHENOLIC METABOLISM AND INTERNAL BREAKDOWN (CHILLING INJURY) OF PEACH FRUIT." HortScience 25, no. 11 (November 1990): 1356H—1357. http://dx.doi.org/10.21273/hortsci.25.11.1356.
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Internal breakdown (IB) is the limiting factor in the storage and postharvest handling of stone fruits. The symptoms of IB appear when fruits are kept for prolonged periods at temperatures below 10C and include leatheriness, mealiness, browning and bleeding of the flesh, and failure to ripen normally. We investigated the changes in phenolic compounds associated with IB of stone fruits. Twenty-eight phenolic compounds were separated by HPLC. Ten of these components were significantly affected by chilling temperatures. The concentration of six phenols changed in response to ripening after chilling temperatures, parallel to the appearance of IB symptoms. Most phenols showed a concentration gradient from the inside to the outside of the fruit, Comparison between peach cultivars showed characteristic differences in phenol metabolism during ripening. In both cultivars the most predominant phenol, chlorogenic acid, showed little change in concentration during storage. The structure of key phenolic compounds will be determined in order to elucidate the biochemical relationship between the phenols and the related enzymes. In this respect, a method was developed to detect phenylalanine ammonia-lyase (PAL) activity in peach fruit.
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Lemma, Grehl, Zech, Mekonnen, Zech, Nemomissa, Bekele, and Glaser. "Phenolic Compounds as Unambiguous Chemical Markers for the Identification of Keystone Plant Species in the Bale Mountains, Ethiopia." Plants 8, no. 7 (July 16, 2019): 228. http://dx.doi.org/10.3390/plants8070228.
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: Despite the fact that the vegetation pattern and history of the Bale Mountains in Ethiopia were reconstructed using pollen, little is known about the former extent of Erica species. The main objective of the present study is to identify unambiguous chemical proxies from plant-derived phenolic compounds to characterize Erica and other keystone species. Mild alkaline CuO oxidation has been used to extract sixteen phenolic compounds. After removal of undesired impurities, individual phenols were separated by gas chromatography and were detected by mass spectrometry. While conventional phenol ratios such as syringyl vs. vanillyl and cinnamyl vs. vanillyl and hierarchical cluster analysis of phenols failed for unambiguous Erica identification, the relative abundance of coumaryl phenols (>0.20) and benzoic acids (0.05—0.12) can be used as a proxy to distinguish Erica from other plant species. Moreover, a Random Forest decision tree based on syringyl phenols, benzoic acids (>0.06), coumaryl phenols (<0.21), hydroxybenzoic acids, and vanillyl phenols (>0.3) could be established for unambiguous Erica identification. In conclusion, serious caution should be given before interpreting this calibration study in paleovegetation reconstruction in respect of degradation and underground inputs of soil organic matter.
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Miroshnichenko, Denis, Artem Bannikov, Leonid Bannikov, and Sergiy Nesterenko. "INFLUENCE OF PHENOLIC COMPOUNDS ON THE OPERATIONAL CHARACTERISTICS OF COAL TAR WASH OIL." Journal of Chemical Technology and Metallurgy 60, no. 1 (January 6, 2025): 103–12. https://doi.org/10.59957/jctm.v60.i1.2025.10.
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The quality of coal tar wash oil plays a key role in industrial processes for the absorption of benzene hydrocarbons from coke oven gas, and oil stability as well as resistance to polymerisation and corrosive oxidation processes are important aspects for ensuring efficient system operation. To ensure low oil consumption, it is necessary to suppress oxidative degradation processes. In this study, the effects of the phenolics of coal tar and its fractions on the antioxidant properties of the absorption oil were investigated. The results showed that phenols are effective oxidation inhibitors, promoting the formation of a protective film on the metal surface and reducing the corrosion rate of carbon steel from 0.56 to 0.33 mm year -1. A particularly strong protective effect was observed when the anthracene fraction of phenolic compounds was used, which possesses slightly reduced acidity with respect to low-molecular-weight phenols. This result can be explained by the weakening of the strength of the intermolecular interactions between phenolic compounds and pyridine bases. This reduces the negative effect of a decrease in the antioxidant abilities of phenols and increases the antioxidant effect of phenols in the anthracene fraction. The addition of various phenolic derivatives to the working absorbing oil did not have a significant effect on the viscosity or flow characteristics of the oils under study. The introduction of phenolic derivatives into the working oil did not change its coke-forming properties. The introduction of the N,N-dimethylformamide additive into coal tar wash oil did not lead to a decrease in coking properties but slightly decreased the viscosity of the working oil. In general, the obtained results are arguments in favour of the inexpediency of phenol extraction from coal tar wash oil to reduce its consumption due to oxidative processes of thickening.
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Kumar, R., Y. Raizner, L. I. Kruh, O. Menashe, H. Azaizeh, S. Kapur, and E. Kurzbaum. "Extracellular laccase production and phenolic degradation by an olive mill wastewater isolate." Grasas y Aceites 69, no. 1 (March 22, 2018): 231. http://dx.doi.org/10.3989/gya.0776171.
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Olive mill wastewater (OMWW) presents a challenge to the control of effluents due to the presence of a high organic load, antimicrobial agents (monomeric-polymeric phenols, volatile acids, polyalcohols, and tannins), salinity and acidity. In this study, the production of extracellular laccase, monomeric or polymeric phenol, from an OMWW isolate based on its ability to biodegrade phenols and gallic acid as a model of phenolic compounds in OMWW was investigated. Phylogenetic analysis of the 16S RNA gene sequences identified the bacterial isolate (Acinetobacter REY) as being closest to Acinetobacter pittii. This isolate exhibited a constitutive production of extracellular laccase with an activity of 1.5 and 1.3 U ml/L when supplemented with the inducers CuSO4 and CuSO4+phenols, respectively. Batch experiments containing minimal media supplemented with phenols or gallic acid as the sole carbon and energy source were performed in order to characterize their phenolic biodegradability. Acinetobacter REY was capable of biodegrading up to 200 mg/L of phenols and gallic acid both after 10 h and 72 h, respectively.
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Martín, Carlos, Helene B. Klinke, Marcelo Marcet, Luis García, Ena Hernández, and Anne Belinda Thomsen. "Study of the phenolic compounds formed during pretreatment of sugarcane bagasse by wet oxidation and steam explosion." Holzforschung 61, no. 5 (August 1, 2007): 483–87. http://dx.doi.org/10.1515/hf.2007.106.
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Abstract The formation of phenolic compounds during pretreatment of sugarcane bagasse was investigated. Bagasse was pretreated by wet oxidation (WO) at 195°C during 15 min under either alkaline or acidic conditions and by steam explosion (STEX) at 205°C during 10 min. The total content of phenolic compounds in the prehydrolysates was determined spectrophotometrically. Under acidic and alkaline WO conditions, 3.8% (w/w) and 3% phenols were found, respectively. STEX gave rise to 1.9% phenols. Individual phenols were identified by GC-MS. Phenylpropanoid derivatives, such as p-coumaric and ferulic acids, accounted for more than 50% of the phenols identified in STEX prehydrolysates. In WO prehydrolysates, on the other hand, phenols lacking the propanoid side chain were predominant. Of the latter, p-hydroxybenzaldehyde was the most abundant phenol, with concentrations of 0.27% (acidic conditions) and 0.15% (alkaline conditions). As expected, high concentrations of oxidised compounds were generally observed in WO prehydrolysates, such as carboxylic acids, aldehydes and ketones. This is a true reflection of the oxidative conditions during WO pretreatment.
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Mena, Pedro, Cristiana Mignogna, Nicole Tosi, Elisa Monica, Vicente Agulló, Alice Rosi, Luca Narduzzi, et al. "Development of an Oral (Poly)Phenol Challenge Test (Opct) to Identify Aggregate Metabotypes for Dietary (Poly)Phenols and Their Drivers: A Study Protocol." Current Developments in Nutrition 6, Supplement_1 (June 2022): 1148. http://dx.doi.org/10.1093/cdn/nzac072.020.
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Abstract Objectives Evidence shows that bioactive (poly)phenols are pivotal in the prevention of chronic diseases, in particular in cardiometabolic health. However, the inter-individual variability existing in their bioavailability and physiological response can impact their true efficacy. Individuals showing similar metabolic profiles for specific (poly)phenols can be clustered into phenolic metabotypes, while comprehensive phenolic metabolic profiles derived from main dietary (poly)phenols could be referred to as “aggregate phenolic metabotypes”. The main aim of the study is to identify aggregate phenolic metabotypes and the determinants related to their formation. Methods An intervention study is carried out on 300 healthy volunteers (18–74 y) which are asked to provide information on dietary habits, smoking, physical activity, sleeping, anthropometric measures, health status, and biological samples. Subjects undergo a standardised oral (poly)phenol challenge test consisting in an acute supplementation of several classes of dietary (poly)phenols. Urine samples collected during the following 24h are analysed through UPLC-IMS-HRMS to assess the individual urinary excretion of phenolic metabolites, allowing aggregate metabotype clustering. Blood samples are analysed to determine common cardiometabolic health biomarkers, and buffy coat processed to isolate peripheral blood mononuclear cells (PBMCs) used for whole-genome genotyping. Transcriptomic signatures in PBMCs are also assessed. Gut microbiota composition will be profiled by shallow shotgun metagenomics. Cardiometabolic risk scores are also computed. Predictive models will be used to assess the determinants of inter-individual variation in (poly)phenol metabolism, providing indications in the cardiometabolic health status of each individual. Results Preliminary results are expected to be available for mid-2023. Conclusions Metabotyping according to the metabolism of the whole set of dietary (poly)phenols may thus represent a promising attempt for cardiometabolic health promotion through personalised nutrition initiatives. Funding Sources This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme.
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Dhakshinamoorthy, Suganthagunthalam, Kahpui Mariama, Annemie Elsen, and Dirk De Waele. "Phenols and lignin are involved in the defence response of banana (Musa) plants to Radopholus similis infection." Nematology 16, no. 5 (2014): 565–76. http://dx.doi.org/10.1163/15685411-00002788.
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The role of lignin and phenols in plant defence ranges from preformed characteristic to inducible physical and chemical response against nematode infection. Our study shows the involvement of lignin and phenols in the defence of two newly identified resistant banana (Musa) genotypes to burrowing nematode Radopholus similis infection. Results were compared with reference resistant and susceptible banana cultivars. Histochemical analysis of root cross sections showed a more extensive secondary cell wall lignification of vascular bundles in R. similis-infected plants than in the nematode non-infected plants. Increased extensive lignification was not associated with the cortex cells that are directly attacked by the nematode. This showed that the increased lignification is a general defence response to protect the vascular bundle from damage rather than resisting the nematode development and reproduction at the root cortex. Histochemical localisation showed no preformed phenolic cells in the cortex of the non-infected, R. similis-resistant and -susceptible Musa genotypes. By contrast, phenolic substances were the major constituents of the nematode-infected necrotic cells. Phenols and lignin contents were also quantitatively assayed. The Folin-Ciocalteu assay confirmed the increase in phenol content of nematode-infected root cells. Phenol content in nematode-infected plants was twice the amount of phenol content in nematode non-infected plants at 3 weeks after infection. This is possibly due to the biosynthesis or accumulation of secondary metabolites such as phenolic phytoalexins in the nematode infection sites of all the banana genotypes. This study clearly demonstrates that phenols and lignin play an important role in the defence mechanisms of Musa to R. similis infection.
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Kochana, Jolanta, Juliusz Adamski, and Andrzej Parczewski. "A Critical View on the Phenol Index as a Measure of Phenol Compounds Content in Waters. Application of a Biosensor." Ecological Chemistry and Engineering S 19, no. 3 (January 1, 2012): 383–91. http://dx.doi.org/10.2478/v10216-011-0028-5.
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A Critical View on the Phenol Index as a Measure of Phenol Compounds Content in Waters. Application of a BiosensorPhenol index is considered as an important indicator of water purity and quality. Usually phenol index is determined by a spectrophotometric method the calibration being based on phenol standards. Unfortunately, the absorptivities of different phenols compounds differ from each other. This leads to significant uncertainty concerning content of phenols in water. It is shown that the same shortage of the phenol index appears also if it is determined using an amperometric biosensor based on tyrosinase. The sensitivity of the biosensor response to four phenol compounds: phenol, catechol, 3-cresol and 4-chlorophenol was examined, as well as possible interactions between phenols, according to 24factorial experiment. It was proved that individual phenols affect phenol index independently from each other,ieno significant interaction between phenols was detected. However, sensitivity of the biosensor to different phenols is not the same. Relationship between phenol index and concentrations of phenols in water is discussed.
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Sithole, Bishop B., and David T. Williams. "Halogenated Phenols in Water at Forty Canadian Potable Water Treatment Facilities." Journal of AOAC INTERNATIONAL 69, no. 5 (September 1, 1986): 807–10. http://dx.doi.org/10.1093/jaoac/69.5.807.
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Abstract Samples of raw and treated water were collected once in each of 3 seasons at 40 potable water treatment plants across Canada and were analyzed for phenol and 33 halogenated phenolic compounds including chlorophenols, bromophenols, bromochlorophenols, and chloroguaiacols. Eighteen of the compounds were not found at any treatment plant; phenol and each of the remaining halogenated phenols were found in at least 1 sample. Pentachlorophenol was the only halogenated phenolic compound found in more than 20% of the raw water samples in the fall and winter samples at levels up to 53 ng/L with mean values of 1.9 and 2.8 ng/L, respectively. No halogenated phenols were detected in raw water summer samples. The halogenated phenols found most frequently in treated water samples were 4-chloro-, 2,4-dichloro-, 2,4,6- trichloro-, and bromodichlorophenols. Mean values were less than 15 ng/L and maximum values seldom exceeded 100 ng/L. Most of the positive values for the treated water samples were found at 8 of the 40 treatment plants but no correlations could be found between halogenated phenol levels and raw water type, treatment process, or chemical dosages.
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Ortega, Maray, Raydel Manrique, Romel Jiménez, Miriam Parreño, Marcelo E. Domine, and Luis E. Arteaga-Pérez. "Secondary Amines from Catalytic Amination of Bio-Derived Phenolics over Pd/C and Rh/C: Effect of Operation Parameters." Catalysts 13, no. 4 (March 27, 2023): 654. http://dx.doi.org/10.3390/catal13040654.
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The production of renewable chemicals using lignocellulosic biomass has gained significant attention in green chemistry. Among biomass-derived chemicals, secondary amines have emerged as promising intermediates for synthetic applications. Here, we report a systematic study on the reductive amination of phenolics with cyclohexylamine using Pd/C and Rh/C as catalysts. The catalytic tests were performed in batch reactors under different reaction conditions (various: amine concentration (0.1–0.4 mol/L), hydrogen pressure (0–2.5 bar), temperature (80–160 °C), and substituted phenols (phenol, o-cresol, p-cresol, and methoxyphenol)) and using tert-amyl alcohol as a solvent. The experimental observations were consistent with a multi-step mechanism, where hydrogenation of phenol to cyclohexanone is followed by condensation of the ketone with cyclohexylamine to form an imine, which is finally hydrogenated to produce secondary amines. In addition, there was evidence of parallel self-condensation of the cyclohexylamine. The study also supported a limited dehydrogenation capacity of Rh/C, unlike Pd/C, which increases this capacity at higher temperatures generating a higher yield of cyclohexylaniline (up to 15%). The study of the alkylated phenols demonstrated that the nature and propensity of hydrogenation of the phenolic controls their amination. Kinetic analysis revealed reaction orders between 0.4 and 0.7 for H2, indicating its dissociative adsorption. Meanwhile, phenol’s order (between 1–1.8) suggests a single participation of this compound in the hydrogenation step. The order of 0.4 for cyclohexylamine suggests its participation as a surface-abundant species. The apparent activation energies derived from a power law approximation were of 37 kJ/mol and 10 kJ/mol on Pd/C and Rh/C, respectively.
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Balahouane, Abdelghani Mounir, Mohamed Lakhdar Belfar, Yacine Moussaoui, and Nadjib Benosmane. "Use of Polymer Inclusion Membrane for the Separation of Phenols Compounds Mixture from Dilute Aqueous Solutions." Int. J. of Membrane Science and Technology 9, no. 1 (August 18, 2022): 26–32. http://dx.doi.org/10.15379/2410-1869.2022.09.01.04.
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Abstract: Separation of phenolic compounds mixture namely: phenol, resorcinol, Bisphenol A from dilute aqueous solutions by polymer inclusion membrane using Cellulose triacetate (CTA) as support was investigated as a means of recovering Bisphenol A from mixture of phenolic compounds. The effects of parameters influencing the separation performance were studied in terms of permeation flux and selectivity. For competitive transport of phenols across PIM with RC8 + NPOE, the selectivity order was Bisphenol > Phenol > Resorcinol. The high permselectivity of the membrane to Bisphenol A was primarily due to its high affinity towards calixresorcinarene macrocycle. This is of particular interest from an industrial point of view because the enriched phenol permeate can be easily recovered upon phase separation. The prepared PIM were characterized by using Raman spectroscopy, XPS and scanning electron microscopy (SEM) techniques.
Keywords: PIM, CTA, Membrane separation, Phenols mixture, Bisphenol A, Wastewater treatment.
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Sui, Xin Jin, and Shu Bin Wu. "Study on Mechanism of Action of Catalysts on Liquefaction of Bagasse Alkali Lignin." Advanced Materials Research 383-390 (November 2011): 6145–50. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.6145.
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Bagasse alkali lignin is the primary constituent of pulping black liquor. The phenolic products such as phenol, 2,6-dimethoxy-phenol and 2-methoxy-phenol were obtained by catalytic liquefaction from bagasse alkali lignin, with the aim of enhancing its use value. In the investigation, under optimal conditions, using SiO2-Al2O3 or FeS as catalyst, the phenols yield reached 54.10% and 55.18%, respectively. HPLC spectrum showed that the phenolic products of them were different. FT-IR and H-NMR spectrums showed that, using SiO2-Al2O3 as the catalyst, the α-O-4 and β-O-4 ether bonds and C-Cα bonds of lignin units were prone to break, forming 2,6-dimethoxy-phenol, 2-methoxy-phenol and phenol. While FeS action was more difficult, the α-O-4 and β-O-4 ether bonds and Cα-Cβ bonds of lignin units broke down. Then, the introduction of additional hydroxyl groups from glycols consequently increased the final product solubility. At the same time, Cα–C bond of the phenylpropane linkage was broken to produce phenolic chemicals. Third, part of the phenylpropane linkage was prone to break Cα–Cβ bond and structural rearrangement occurred. So the content of 2-methoxy-4-methyl-phenol and the total yield of phenols were high.
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Kalinowski, Andzrej, and Sławomir Bartkowiak. "Chromatographic analysis of phenol compounds in six natural populations of Anthyllis vulneraria (L.)." Acta Societatis Botanicorum Poloniae 48, no. 2 (2015): 205–15. http://dx.doi.org/10.5586/asbp.1979.018.
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Thin-layer chromatography was used to study the phenol composition in individual plants from six natural populations of <i>Anthyllis<i> collected from three distinct geographic regions of Poland. The results showed a variability of the phenols in the examined populations. The populations from Wielkopolska region proved to be most variable, showing the greatest number of phenols. The lowest number of the phenols studies was found in the Tatry populations. Each population showed its own particular spectrum of phenolic compounds. It was found that the populations originating from similar habitats showed more common spots than those from different regions. Populations from the Tatra region were found to differ most from the rest.
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Olivas-Aguirre, Miguel, Liliana Torres-López, Igor Pottosin, and Oxana Dobrovinskaya. "Phenolic Compounds Cannabidiol, Curcumin and Quercetin Cause Mitochondrial Dysfunction and Suppress Acute Lymphoblastic Leukemia Cells." International Journal of Molecular Sciences 22, no. 1 (December 28, 2020): 204. http://dx.doi.org/10.3390/ijms22010204.
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Anticancer activity of different phenols is documented, but underlying mechanisms remain elusive. Recently, we have shown that cannabidiol kills the cells of acute lymphoblastic leukemia (ALL) by a direct interaction with mitochondria, with their consequent dysfunction. In the present study, cytotoxic effects of several phenolic compounds against human the T-ALL cell line Jurkat were tested by means of resazurin-based metabolic assay. To unravel underlying mechanisms, mitochondrial membrane potential (∆Ψm) and [Ca2+]m measurements were undertaken, and reactive oxygen species generation and cell death were evaluated by flow cytometry. Three out of eight tested phenolics, cannabidiol, curcumin and quercetin, which displayed a significant cytotoxic effect, also dissipated the ∆Ψm and induced a significant [Ca2+]m increase, whereas inefficient phenols did not. Dissipation of the ∆Ψm by cannabidiol was prevented by cyclosporine A and reverted by Ru360, inhibitors of the permeation transition pore and mitochondrial Ca2+ uniporter, respectively. Ru360 prevented the phenol-induced [Ca2+]m rise, but neither cyclosporine A nor Ru360 affected the curcumin- and quercetin-induced ∆Ψm depolarization. Ru360 impeded the curcumin- and cannabidiol-induced cell death. Thus, all three phenols exert their antileukemic activity via mitochondrial Ca2+ overload, whereas curcumin and quercetin suppress the metabolism of leukemic cells by direct mitochondrial uncoupling.
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Yeszhanov, A. B., and S. S. Dosmagambetova. "Phenol solutions treatment by using hydrophobized track-etched membranes." Bulletin of the Karaganda University. "Chemistry" series 99, no. 3 (September 30, 2020): 99–109. http://dx.doi.org/10.31489/2020ch3/99-109.
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Phenols are one of the most common surface water pollution. The discharge of phenolic waters into water bodies and streams sharply degrade their general sanitary condition, since these compounds have a toxic effect, and phenols can intensively absorb oxygen dissolved in water, which negatively affects the life of organisms in water bodies. Therefore, water treatment of phenols is an important environmental problem. In this study, the hydrophobic polyethylene terephthalate track-etched membranes (PET TeMs) were tested in water treatment from phenol by direct contact membrane distillation (DCMD). Hydrophobic PET TeMs were obtained by UV-graft polymerization of styrene, triethoxyvinylsilane with the addition of vinylimidazole (VIM), as well as by coating with fluorine-containing silanes. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and liquid entry pressure (LEP) analysis were used for membrane characterization. The contact angle after modification of PET TeMs was reached more than 130°. The efficiency of water purification from phenol was evaluated by water-flux measurements and fluorimetric method. The phenols solution was used at a concentration of 0.5, 1 and 2 g/l. The largest permeate flux of hydrophobized membranes was 1.1 kg/ m2•h.
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Lu, C. J., and S. J. Chen. "The Effects of the Secondary Carbon Source on the Biodegradation of Chlorinated Phenols in Biofilm Reactors." Water Science and Technology 26, no. 9-11 (November 1, 1992): 2113–16. http://dx.doi.org/10.2166/wst.1992.0674.
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The effects of the presence of a secondary carbon source on the biodegradation of chlorinated phenols were studied with column biofilm reactors. The biodegradability of chlorinated phenols was studied with a series of batch reactors. The biodegradability of chlorinated phenols was to follow the order of phenol > 2,4-dichlorophenol > 4-chIorophenol > 2,4,6-trichlorophenol > 2-chlorophenol > 3-chloro-phenol. The presence of a relatively more biodegradable but higher chlorinated phenol, such as 2,4,6-trichlorophenol, enhanced the biodégradation of a less chlorinated butrecalcitrantphenol, such as 2-chlorophenol. The addition of phenol, an easily biodegradable compound, generally decreased the biodegradation of chlorinated phenols.
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Bisaillon, Jean-Guy, François Lépine, Réjean Beaudet, and Michel Sylvestre. "Potential for carboxylation–dehydroxylation of phenolic compounds by a methanogenic consortium." Canadian Journal of Microbiology 39, no. 7 (July 1, 1993): 642–48. http://dx.doi.org/10.1139/m93-093.
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An anaerobic consortium that carboxylated and dehydroxylated phenol to benzoate, and 2-cresol to 3-methylbenzoic acid, under methanogenic conditions was studied. Phenol induced this transformation activity. Addition of 4-hydroxypyridine or an increase in the concentration of proteose peptone to 0.5% (w/v) delayed the transformation. Phenol enhanced the rate of transformation of 2-cresol whereas 2-cresol delayed the transformation of phenol. Phenols with ortho-substitutions (chloro-, fluoro-, bromo-, hydroxyl-, amino-, or carboxyl-) were transformed to meta-substituted benzoic acids. However, meta- and para-substituted phenols (cresols, fluorophenols, and chlorophenols) were not transformed. Phenol was most rapidly metabolized, followed by catechol, 2-cresol, 2-fluorophenol, 2-aminophenol, 2-chlorophenol, 2-hydroxybenzoic acid, and 2-bromophenol. The consortium O-demethylated anisole to phenol and 2-methoxyphenol to catechol, and oxidized 2-hydroxybenzyl alcohol to 2-hydroxybenzoic acid. Aniline, 2-ethylphenol, 2-hydroxypyridine, 2-acetamidophenol, 2,6-dimethylphenol, 2-phenylphenol, and 1-naphthol were not metabolized.Key words: phenolic compounds, methanogenic consortium, carboxylation–dehydroxylation.
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Duguet, J. P., B. Dussert, J. Mallevialle, and F. Fiessinger. "Polymerization Effects of Ozone: Applications to the Removal of Phenolic Compounds from Industrial Wastewaters." Water Science and Technology 19, no. 5-6 (May 1, 1987): 919–30. http://dx.doi.org/10.2166/wst.1987.0270.
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Degradation of phenols by ozone has been extensively studied but the oxidative coupling pathway of ozone resulting in a phenol polymerization has not been largely investigated. Application of low ozone dose in solutions of 2.4 dichlorophenol and salicylic acid is characterized by the formation of high molecular compounds which are partially insoluble. Numerous polymers have been identified by gas chromatography coupled with mass spectrometry. Application of the polymerization effect of ozone to petrochemical and coking wastewaters containing phenols give similar results. In each case, phenolic compounds are efficiently removed, even if a large organic content is present. In the case of petrochemical wastewater, where phenols represent only 30% of TOC, the ozone effects are not sufficient to merit an ozonation step on the present treatment line. On the other hand, when phenols represent the greater part of the organics, as in coking wastewater, an important fraction of insoluble compounds, easily removed by filtration, are formed.
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Fukushima, Akiyoshi, Hioaki Hase, and Koshi Saito. "Adsorption of plant phenols by polystyrene resins." Acta Societatis Botanicorum Poloniae 56, no. 3 (2014): 485–97. http://dx.doi.org/10.5586/asbp.1987.045.
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Adsorption of nine plant phenols by nine polystyrene ion-exchange resins was investigated in an experimental model system. The phenols were adsorbed by Amberlite CG-120 more efficiently than any other acidically charged resins tested in this study. They were also taken up by anion exchangers. Among them Dowex 1-X8 was found to show the strongest effect on the adsorption of the phenolic constituents applied. A comparison of the efficiency of plant phenol adsorption between two different types of the synthetic polymers revealed that the basically charged polystyrenes had more prefarable affinities for phenols than cation exchangers. For example, the ratio of the efficiency between Amberlite CG-120 and Dowex 1-X8 was roughly calculated to be 3:7 under the present experimental conditions. The adsorption rate of the test phenols was raised mostly by increasing the amount of the resins added, if they were mixed with effective polymers in the incubation model system.
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Salvini, Simonetta, Francesco Sera, Donatella Caruso, Lisa Giovannelli, Francesco Visioli, Calogero Saieva, Giovanna Masala, et al. "Daily consumption of a high-phenol extra-virgin olive oil reduces oxidative DNA damage in postmenopausal women." British Journal of Nutrition 95, no. 4 (April 2006): 742–51. http://dx.doi.org/10.1079/bjn20051674.
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Extra-virgin olive oils (EVOO), high in phenolic compounds with antioxidant properties, could be partly responsible for the lower mortality and incidence of cancer and CVD in the Mediterranean region. The present study aims to measure oxidative DNA damage in healthy human subjects consuming olive oils with different concentrations of natural phenols. A randomised cross-over trial of high-phenol EVOO (high-EVOO; 592mg total phenols/kg) V low-phenol EVOO (low-EVOO; 147mg/kg) was conducted in ten postmenopausal women in Florence. Subjects were asked to substitute all types of fat and oils habitually consumed with the study oil (50g/d) for 8 weeks in each period. Oxidative DNA damage was measured by the comet assay in peripheral blood lymphocytes, collected at each visit during the study period. Urine samples over 24h were collected to measure the excretion of the olive oil phenols. The average of the four measurements of oxidative DNA damage during treatment with high-EVOO was 30% lower than the average during the low-EVOO treatment (p=0·02). Urinary excretion of hydroxytyrosol and its metabolite homovanillyl alcohol were significantly increased in subjects consuming high-EVOO. Despite the small sample size, the present study showed a reduction of DNA damage by consumption of an EVOO rich in phenols, particularly hydroxytyrosol.
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Frías-Zepeda, M. Estela, and Martha Rosales-Castro. "Effect of extraction conditions on the concentration of phenolic compounds in Mexican oregano (Lippia graveolens Kunth) residues." Revista Chapingo Serie Ciencias Forestales y del Ambiente 27, no. 3 (August 31, 2021): 367–81. http://dx.doi.org/10.5154/r.rchscfa.2020.10.066.
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Introduction: Mexican oregano (Lippia graveolens Kunth) leaves are marketed for use in food and for essential oil extraction. Phenolic compounds with antioxidant properties can be obtained from the residues (leaves without oil and stems) under appropriate extraction conditions. Objective: To evaluate the effect of extraction solvent and mass/volume ratio on phenolic compounds concentration and their antioxidant capacity in oregano residues. Materials and methods: Residual leaf (without oil) and stems of oregano were used to obtain extracts with 30, 50 and 80 % aqueous ethanol (ET30, ET50, ET80, respectively) and solvent mass/ volume ratios (1:10, 1:20 and 1:30). Yield in solids, total phenols concentration and flavonoids, and antioxidant capacity were evaluated in the extracts. Similarity analysis between extracts was performed by HPLC-DAD and the main phenols were identified by UPLC-MS. Results and discussion: Extract yields, phenol concentrations and flavonoids and antioxidant capacity for leaves were higher than for stems. The maximum concentration of phenols was obtained with ET80 and 1:30 ratio, which indicates better dissolution in ethanol than in water. The extracts ET50 and ET80 had chromatographic similarity of phenols in both residues; naringenin, taxifolin, eriodictyol, caffeic acid and luteolin were the major compounds. Conclusion: Ethanol-water concentrations and mass/solvent ratios are feasible for obtaining flavonoid and non-flavonoid phenolic compounds with antioxidant capacity from oil-free leaves and stems of oregano.
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T, Thiruveni. "MICROBIAL AND HERBIVORE INDUCED PHYTOCHEMICAL CHANGES IN OKRA AGAINST SHOOT AND FRUIT BORER, EARIAS VITTELLA (FAB.)." Journal of Biopesticides 5 (April 1, 2012): 223–27. https://doi.org/10.57182/jbiopestic.5.0.223-227.
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Microbial andherbivore induced phytochemical changes were studied in okra variety, Arkaanamika and hybrid, CoBhH1, againstshoot and fruit borer, Earias vittella. Induction was done either bymicrobial alone (microbial talc-based bioformulation Pseudomonas fluorescens(Pf1), Beauveria bassiana B2 isolate, Pf1+B2 consortia) or by bothmicrobial and herbivore (E. vittella infestation). Herbivore alone infestedplants served as infested control and undamaged plants left as absolutecontrol. Biochemical pathways encompassing induced resistance viz.,phenols and oxidizing defense enzymes such as peroxidase (PO), phenylalanineammonia lyase (PAL) and polyphenol oxidase (PPO) were assessed to envisage thedevelopment of induced resistance. Accumulation of phenol was high in Pf1+B2consortia inoculated plants as against absolute control in variety, Arkaanamika and hybrid, CoBhH1. Inoculation with both microbial consortia and E.vittella caused 9.8 times increased accumulation of phenolics in ArkaAnamika and 8.6 times in CoBhH1. Defense enzymes activity was alsosignificantly higher in Pf1 + B2 consortia treated plants as against absolutecontrol. Further, infestation by E. vittella resulted in the enhancementof accumulation of phenols, induction of PO, PAL and PPO activity. In absolutecontrol, CoBhH1 had higher phenolic accumulation and increased activity ofdefense enzymes than Arka Anamika.
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Stoyanov, Nikolay, Panko Mitev, Mariana Galabova, and Silvia Tagareva. "Phenolic compounds extractability from Melnik 55 grape solid parts during fruit maturity." BIO Web of Conferences 58 (2023): 01016. http://dx.doi.org/10.1051/bioconf/20235801016.
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Samples from Melnik 55 grape variety (Vitis vinifera) were collected from different stage of grape maturity. Grape seeds and skins from each sample were separated and extracted with model wine solutions with increasing alcohol content simulated alcohol accumulation during wine fermentation. Total phenolic compounds, anthocyanins, skin pigments and tannins in each sample were determined. During grape ripening not only total phenols content of grape skins and seeds are changed but also their extractability. Ethanol released during wine fermentation is strong phenol extragents but its role is getting smaller as riper is the grape. This tendency is more pronounced in seeds phenolics extractability than in skins.
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Jia, Yong Hui. "Technical Study on Relationship between Terpene Phenolic Compounds and Health." Advanced Materials Research 518-523 (May 2012): 529–32. http://dx.doi.org/10.4028/www.scientific.net/amr.518-523.529.
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The hydroxy derivatives of aromatic hydrocarbons which have hydroxyl getup directly attached to the ring are called phenols. Small amounts of water dissolved in phenol lower the melting point to below the room temperature. This paper summarized the bioactivities and safety issues of Terpene Phenolic, and its functions, biosynthetic mechanisms, characteristics and clearing strategies of terpene phenolic compounds.
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GIMENO, O., M. CARBAJO, F. BELTRAN, and F. RIVAS. "Phenol and substituted phenols AOPs remediation." Journal of Hazardous Materials 119, no. 1-3 (March 17, 2005): 99–108. http://dx.doi.org/10.1016/j.jhazmat.2004.11.024.
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Mikulic Petkovsek, M., F. Stampar, and R. Veberic. "Seasonal changes in phenolic compounds in the leaves of scab-resistant and susceptible apple cultivars." Canadian Journal of Plant Science 89, no. 4 (July 1, 2009): 745–53. http://dx.doi.org/10.4141/cjps08202.
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Leaf samples were collected from apple varieties susceptible and resistant to apple scab [Venturia inaequalis (Cke.) Wint.] from June to September for 2 yr between 2005 and 2006. These were analyzed for phenolic compounds, using high-performance liquid chromatography (HPLC). In the apple leaves, the following hydroxycinnamic acids were detected: chlorogenic, caffeic and p-coumaric acids; the following dihydrochalcone: phloridzin, and the following flavonoids: epicatechin, catechin, rutin and quercitrin. The total of phenolic compounds in apple leaves was determined spectrophotometrically, using the Folin-Ciocalteu method. During the growing season, the content of phenolic compounds changed and was related to the physiological stage of the tissue and cultivar used. Each phenolic compound had its own curve of seasonal changes in concentration. In 2005 there was no significant change in total phenols during the growing season. In 2006, their content changed significantly during the growing season; statistically the highest content of total phenols was found in the leaves in August. Total phenols as well as single phenolics were statistically higher in resistant than in susceptible apple varieties for both years.Key words: Malus × domestica Borkh., leaves, phenolic compounds, seasonal changes, Venturia inaequalis (Cke.) Wint., resistance
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Vershinin, V. I., and L. S. Bazhenova. "Application of inverted multivariate calibrations to determination of the total content of phenols." Industrial laboratory. Diagnostics of materials 89, no. 9 (September 24, 2023): 5–12. http://dx.doi.org/10.26896/1028-6861-2023-89-9-5-12.
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The total content (cΣ) of toxic phenols in water is usually determined using the procedures which include the introduction of a group reagent, measurement of the generalized signal (AΣ) at a selected wavelength, and assessment of cΣ in terms of C6H5OH. The use of diazotized sulfanilic acid (DSA) as a group reagent leads to the errors of cΣ determination which do not exceed 30% thus ensuring more adequate estimates of cΣ than measuring phenolic index. We suppose that further reduction of errors in group analysis would be possible with multiwavelength measurements and multivariate calibrations but these promising techniques have not been used yet for the determination of total phenol. To check up this assumption, model multicomponent colored solutions of the known composition were prepared and analyzed. These model mixtures contained simultaneously up to 5 different phenols with a total concentration ranged from 15 to 70 μmol/L. After converting all phenols to corresponding azo-dyes their generalized signals were measured at m wavelengths in the UV region of the spectrum 10 minutes after mixing the solutions. The results of group analysis were calculated with the multivariate calibrations; the recalculation of AΣ values to standard substance concentration we used only for comparison. The inverted multivariate calibrations were calculated with AΣ values of n model mixtures which formed a training set. For optimized conditions (m = 7, n = 10) the systematic error of cΣ prediction is less than 13 % rel., that is half of errors for total index calculation. Therefore, inverted multivariate calibrations can be rather useful to control the total content of phenolics in natural and waste waters (instead of the total indices). However, systematic errors raised sharply when the analyzed sample contained some individual phenols which were absent in samples of the training set; in such cases the errors can increase up to 80 % rel. To maximize the correctness of corresponding techniques, it is desirable to elucidate beforehand the qualitative composition of phenol mixtures in water samples under study and take it into account when the multivariate calibration is used.
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Wood, C. D., and V. E. Plumb. "Total phenols and protein precipitation assays as indicators of the inhibitory effects of phenols on rumen micro-organisms." Proceedings of the British Society of Animal Production (1972) 1994 (March 1994): 75. http://dx.doi.org/10.1017/s0308229600026222.
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Phenolics, such as tannins, have been implicated as inhibitors of digestibility. A wide range of assays for measuring phenols have been proposed (reviewed by Hagerman and Butler, 1989) but there is little experimental evidence to indicate which are most appropriate for assessing nutritive value. The objective of this study was to investigate correlations between phenol assays and the effects of phenolics on in vitro fermentation by rumen micro-organisms to identify which assays most reliably indicated the extent of these effects.Extracts were prepared from 12 Bolivian tree leaf samples using 70% aqueous acetone (500mg dried sample extracted with 5 ml solvent) and analysed for total phenols (TP) by the Prussian Blue method (Price and Butler, 1977), protein precipitation activity (PPA) by a radial diffusion technique (Hagerman, 1987) and condensed tannins (CT) by acid butanol (Porter et al, 1986). The samples used are listed in Table 1.
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Sarma, G. V. S., P. Bala Bharathi, J. V. S. Murty, G. M. J. Raju, K. V. Ramesh, and C. Bhaskara Sarma. "Improvements in Recovery Efficiencies of Phenols from Phenol Fraction Using Two-Stage Alkali Treatment." TECNICA ITALIANA-Italian Journal of Engineering Science 65, no. 2-4 (July 30, 2021): 442–45. http://dx.doi.org/10.18280/ti-ijes.652-443.
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Experiments were carried out for the recovery of phenols from phenol fraction procured from tar distillation plant of Visakhapatnam steel plant by two stage alkali treatment, to study the effect of two-stage alkali treatment on the yield of phenols from phenol fraction. The results of the present investigation showed that two-stage alkali wash gives better yields of phenols compared to single stage alkali wash of the same phenol fraction with the same strength of alkali solution (NaOH). Also it is shown that maximum yield of phenols could be obtained with 35% strength of alkali. In the first stage 70% of 35% strength solution was used while in the second stage treatment 30% of the same strength solution was used. Improvements in the recovery efficiencies of phenols were found to be 47% more than those reported earlier in the single-stage extraction studies for the same strength of alkali solutions.
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Mahiudddin, Md, A. N. M. Fakhruddin, and Abdullah-Al-Mahin. "Degradation of Phenol via Meta Cleavage Pathway by Pseudomonas fluorescens PU1." ISRN Microbiology 2012 (January 23, 2012): 1–6. http://dx.doi.org/10.5402/2012/741820.
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Degradation of phenolics by members of soil microflora is an important means by which these substances are removed from the environment thus reducing environmental pollution. Biodegradation by microorganisms offers unique opportunities to destroy or render phenolic compounds. A bacterium, PU1, identified as Pseudomonas fluorescens PU1, was investigated for its ability to grow on and degrade phenols as sole carbon sources in aerobic shaking batch culture. The organism degraded up to 1000 ppm of phenol using meta cleavage pathway. The pathways for phenol degradation were proposed by the identification of metabolites and assay of ring cleavage enzymes in cell extracts. Phenol was degraded via catechol with subsequent metaring cleavage. Cell growth increased as the phenol concentrations increased up to 1000 ppm phenol. The biodegradation efficiency, degradation extent, and metabolic pathway of phenol were determined to provide useful clues for further application of this isolate in the engineered bioremediation systems. The paper's results suggest that Pseudomonas fluorescens PU1 strain could be a good candidate for remediation of phenol contaminants from heavily polluted sites.
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Tatsumi, K., H. Ichikawa, and S. Wada. "Dephenolization from aqueous solution by treatment with peroxidase and a coagulant." Water Science and Technology 30, no. 9 (November 1, 1994): 79–86. http://dx.doi.org/10.2166/wst.1994.0448.
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To develop a new enzymatic method for removal of phenols from wastewater, the reaction of phenols with horseradish peroxidase was investigated in the presence or absence of a coagulant. Phenols are effectively removed by treatment with peroxidase and a cationic polymer coagulant. The coagulant precipitated enzymatic products of phenol, and reduced the inactivation of peroxidase caused by reaction of products from phenol with the enzyme. This stabilization of peroxidase lessened the amount of enzyme required for phenol removal. Reaction of the coagulant with products from phenol resulted in a large precipitate and only simple filtration was required for separation.
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Arvin, Erik, Bjørn K. Jensen, and Anders Torp Gundersen. "Biodegradation Kinetics of Phenols in an Aerobic Biofilm at Low Concentrations." Water Science and Technology 23, no. 7-9 (April 1, 1991): 1375–84. http://dx.doi.org/10.2166/wst.1991.0590.
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Aerobic biodegradation of the phenols: phenol, 2-methylphenol, 4-methylphenol, 2,4-dimethylphenol, 3,5-dimethylphenol and 2,4,6-trimethylphenol was studied in a biofilm reactor to establish kinetic constants under conditions where the phenols were the sole carbon sources. Phenol concentrations were very low, in the µg/l concentration range. 2,4,6-trimethylphenol was not degraded. The degradation of the other phenols was 1'st order at concentrations in the bulk phase below 20-50 µg/l. Zero order reaction seemed to govern the reaction above 200 µg/l. The l'st order rate constants are 3-30 times higher than the constants calculated for easily degradable organic compounds degraded at 100-1000 times higher concentrations (mg/l range). However, the maximum phenol utilization rates and the Monod constants were much lower compared with constants obtained for the microorganisms grown in the mg/l concentration range. The Monod constant was about 100 times lower. The removal of “total biodegradable phenol” (TB-phenol) was very similar to the removal of a specific compound. The degradation of TB-phenol was l'st order at concentrations below 200 µg/l. When the total biodegradable phenol degradation is near its maximum capacity (o'order reaction) there was a preferential degradation of the most easily degradable phenols, phenol and 2-methylphenol, leading to an apparent inhibition of the degradation of the more slowly degradable phenols, in particular 2,4-dimethylphenol and 3,5-dimethylphenol.
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Yang, Lei, and Hui Zhen Yan. "Modification of Reed Alkali Lignin to Adsorption of Heavy Metals." Advanced Materials Research 622-623 (December 2012): 1646–50. http://dx.doi.org/10.4028/www.scientific.net/amr.622-623.1646.
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We use reed alkali lignin to extract heavy metal adsorbent with the method of phenol modification. Then we study how the phenols addition amount, reaction temperature and reaction time affect the modified products’ adsorption of heavy metal. The results are as follows. The best adsorption of Pb2+, Cd2+, Cr3+ can be got when phenols addition amount is 4g, the reaction temperature is100°C and the reaction time is 90 min. Compared with alkali lignin, the adsorption rate gets an obvious improvement. The removal rate of Pb2+ rises from 92.4 to 97.8%. The removal rate of Cd2+ rises from 44.5 to 63.8%. The removal rate of Cr3+ rises from 43.4 to 62.5%. Also the adsorption rate improves with the increase of phenolic hydroxyl, which shows that the phenolic hydroxylfacilitates adsorption.
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Yang, Jian Qiong, Hai Liu, Lei Peng, and Guo An Luo. "Study on Terpene Phenolic Compounds and its Health Effects." Advanced Materials Research 1004-1005 (August 2014): 924–27. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.924.
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Hydroxy derivatives of aromatic hydrocarbons, have hydroxyl getup directly attached to the ring, which is called phenols. This paper study the bioactivities and safety issues of Terpene Phenolic and its functions, characteristics and clearing strategies of terpene phenolic compounds, so as its biosynthetic mechanisms. The results show that the small amounts of water dissolved in phenol lower the melting point to below the room temperature.
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du Plessis, Heinrich W., Justin W. Hoff, Lucky Mokwena, Marieta van der Rijst, and Neil P. Jolly. "Impact of Yeast Selection on Volatile Phenol Levels of Wines Produced from Smoked-Exposed Juice." Fermentation 7, no. 4 (October 26, 2021): 240. http://dx.doi.org/10.3390/fermentation7040240.
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Grapes exposed to smoke can result in wines that have unacceptable high levels of volatile phenols. High volatile phenols levels have a negative impact on wine quality. This study aimed to determine the levels of volatile phenols in wines produced from smoke-exposed juice by a selection of commercial wine yeasts and to determine if yeast selection affected the perception of smokiness in wine. Commercial white and red wine yeasts were screened for the production of volatile phenols in smoke-exposed Chenin Blanc and Merlot juice. Volatile phenol levels were determined by GC-MS/MS and wines were also subjected to sensory evaluation. Volatile phenol levels in smoked wines varied and was affected by yeast strain. The highest guaiacol levels in Chenin Blanc were found in wines fermented with QA23, while Merlot wines that underwent spontaneous alcoholic fermentation contained the highest levels. The levels of volatile phenols differed significantly between the smoked and unsmoked wines, and the sensory results supported the chemical data. Volatile phenols had a negative effect on Chenin Blanc flavor profiles even when the levels were below odor detection thresholds. Yeast selection is important and can affect the volatile phenol levels and flavor profiles of wines.
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Kolosova, Olga Yu, Viktor G. Vasil’ev, Ivan A. Novikov, Elena V. Sorokina, and Vladimir I. Lozinsky. "Cryostructuring of Polymeric Systems: 67 Properties and Microstructure of Poly(Vinyl Alcohol) Cryogels Formed in the Presence of Phenol or Bis-Phenols Introduced into the Aqueous Polymeric Solutions Prior to Their Freeze–Thaw Processing." Polymers 16, no. 5 (March 1, 2024): 675. http://dx.doi.org/10.3390/polym16050675.
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Poly(vinyl alcohol) (PVA) physical cryogels that contained the additives of o-, m-, and p-bis-phenols or phenol were prepared, and their physico-chemical characteristics and macroporous morphology and the solute release dynamics were evaluated. These phenolic additives caused changes in the viscosity of initial PVA solutions before their freeze–thaw processing and facilitated the growth in the rigidity of the resultant cryogels, while their heat endurance decreased. The magnitude of the effects depended on the interposition of phenolic hydroxyls in the molecules of the used additives and was stipulated by their H-bonding with PVA OH-groups. Subsequent rinsing of such “primary” cryogels with pure water led to the lowering of their rigidity. The average size of macropores inside these heterophase gels also depended on the additive type. It was found also that the release of phenolic substances from the additive-containing cryogels occurred via virtually a free diffusion mechanism; therefore, drug delivery systems such as PVA cryogels loaded with either pyrocatechol, resorcinol, hydroquinone, or phenol, upon the in vitro agar diffusion tests, exhibited antibacterial activity typical of these phenols. The promising biomedical potential of the studied nanocomposite gel materials is supposed.
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Nádudvari, Ádám, Monika J. Fabiańska, and Magdalena Misz-Kennan. "Distribution of phenols related to self-heating and water washing on coal-waste dumps and in coaly material from the Bierawka river (Poland)." Mineralogia 46, no. 1-2 (June 1, 2015): 29–40. http://dx.doi.org/10.1515/mipo-2016-0005.
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AbstractSeveral types of coal waste (freshly-dumped waste, self-heated waste and waste eroded by rain water), river sediments and river water were sampled. The aim was to identify the types of phenols present on the dumps together with their relative abundances. Gas chromatography-mass spectrometry (GC-MS) analyses of a large number of samples (234) statistically underpin the phenol distributions in the sample sets. The largest average relative contents (1.17-13.3%) of phenols occur in the self-heated samples. In these, relatively high amounts of phenol, C1- and C2-phenols reflect the thermal destruction of vitrinite. In fresh coal waste, C2- and C3-phenols that originated from the bacterial/fungal degradation and oxidation of vitrinite particles are the most common (0.6 rel.%). Water-washed coal waste and water samples contain lower quantities of phenols. In the river sediments, the phenols present are the result of bacterial- or fungal decay of coaly organic matter or are of industrial origin.
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Mihelčič, Alenka, Klemen Lisjak, and Andreja Vanzo. "Accelerated Solvent Extraction of Phenols from Lyophilised Ground Grape Skins and Seeds." Beverages 9, no. 1 (January 6, 2023): 4. http://dx.doi.org/10.3390/beverages9010004.
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The efficient extraction of phenols from grapes is an important step for their reliable quantification. The aim was to optimise the lyophilisation process and the extraction of phenols from grape skins and seeds. The phenol extraction yield from lyophilised tissues was investigated with different accelerated solvent extraction (ASE) operating conditions. Skins and seeds were separated from frozen berries and lyophilised without being ground. The weight loss during lyophilisation was followed daily. Phenols were extracted from lyophilised, cryo-ground seeds and skins with ASE at room temperature and 10.3 MPa using 80% aqueous acetone and 60% aqueous methanol. The effects of ASE operational parameters (the number of extraction cycles (ECs) and static time (ST) duration) were investigated. The yield of extracted phenols was evaluated spectrophotometrically by determining total phenolic index at 280 nm (TPI). The weight of skins and seeds significantly dropped after 24 h of lyophilisation and continued to decrease, although not significantly, up until the 9th day. The optimal lyophilisation time was estimated to be 3 days and 5 days for skins and seeds, respectively. The phenol extraction yield was significantly affected after changes of ASE conditions. Based on TPI, the optimal ASE conditions were as follows: (i) lyophilised seeds—eight ECs with 10 min ST using aqueous acetone and then four ECs with 20 min ST using aqueous methanol; (ii) lyophilised skins—eight ECs with 1 min ST using aqueous acetone and then one EC with 20 min ST using aqueous methanol.
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Alekhin, V. S., V. G. Tsederbaum, and A. B. Pershin. "Extraction of phenol from phenolcontaining waters when using extractants." World of petroleum products 03 (2023): 54–58. http://dx.doi.org/10.32758/2782-3040-2023-0-3-54-58.
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Phenol and its derivatives are among the most dangerous pollutants entering the environment as part of wastewater from oil refineries and petrochemical plants, as well as pharmaceutical industry and construction materials. In surface water bodies, phenols occur in the form of their derivatives, namely: free phenols, phenolate ions and phenolates. The listed compounds have different degrees of toxicity, forming humus-like compounds as a result of polymerization and condensation reactions. For this reason, the treatment of phenolic wastewater is a very urgent problem in the petrochemical industry due to the high carcinogenicity of these impurities. Deep purification of water effluents is complicated by the fact that none of the known methods of removing phenols can achieve, with relatively acceptable technical and economic indicators, the required degree of purification. In accordance with the guidance document RD 52.24.480-2006 and the "Instructions for the formation and presentation of operational information on extremely high and high levels of surface water pollution, as well as their accidental pollution" (IGCE, Moscow, 2001), when assessing the pollution of natural waters with phenols, in all cases, 0.001 mg/dm3 is used as the MPC.