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Статті в журналах з теми "Phenolic fractions":
1
Arfan, M., H. Amin, M. Karamać, A. Kosińska, W. Wiczkowski, and R. Amarowicz. "Antioxidant activity of phenolic fractions of Mallotus philippinensis bark extract." Czech Journal of Food Sciences 27, No. 2 (May 25, 2009): 109–17. http://dx.doi.org/10.17221/1056-cjfs.
Анотація:
Phenolic compounds were extracted from <I>Mallotus philippinensi</I> bark using methanol. Six fractions (I–VI) were separated from the extract on a Sephadex LH-20 column using ethanol and acetone-water as the mobile phases and were evaluated for their total antioxidant activity, antiradical activity against DPPH<sup>•</sup> (2,2-diphenyl-1-picrylhydrazyl radical), and reducing power. The total phenolics and tannin contents in the fractions were determined. The content of total phenolics in the fractions ranged from 54 mg/g (fraction I) to 927 mg/g (fraction VI). Condensed tannins were detected in fractions II–VI. Total antioxidant activity (TAA) of phenolic fractions of <I>Mallotus philipinensis</I> bark extract ranged from 0.58 mmol Trolox/g (fraction I) to 6.82 mmol Trolox/g (fraction IV). Fraction IV also showed the strongest antiradical activity against DPPH<sup>•</sup> and reducing power. Several phenolic constituents in the fractions were detected by RP-HPLC using a gradient solvent system with UV-DAD detection.
2
Zhang, Xuan, Yijia Jia, Yanli Ma, Guiguang Cheng, and Shengbao Cai. "Phenolic Composition, Antioxidant Properties, and Inhibition toward Digestive Enzymes with Molecular Docking Analysis of Different Fractions from Prinsepia utilis Royle Fruits." Molecules 23, no. 12 (December 19, 2018): 3373. http://dx.doi.org/10.3390/molecules23123373.
Анотація:
The present study investigated the phenolic profiles and antioxidant properties of different fractions from Prinsepia utilis Royle fruits using molecular docking analysis to delineate their inhibition toward digestive enzymes. A total of 20 phenolics was identified and quantified. Rutin, quercetin-3-O-glucoside, and isorhamnetin-3-O-rutinoside were the major phenolic compounds in the total phenolic fraction and flavonoid-rich fraction. The anthocyanin-rich fraction mainly contained cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside. All of the fractions exhibited strong radical scavenging activities and good inhibition on cellular reactive oxygen species (ROS) generation in H2O2-induced HepG2 cells, as evaluated by DPPH and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Moreover, the powerful inhibitory effects of those fractions against pancreatic lipase and α-glucosidase were observed. The major phenolic compounds that were found in the three fractions also showed good digestive enzyme inhibitory activities in a dose-dependent manner. Molecular docking analysis revealed the underlying inhibition mechanisms of those phenolic standards against digestive enzymes, and the theoretical analysis data were consistent with the experimental results.
3
Syukur, Mighfar, Masitoh Suryaning Prahasiwi, Nurkhasanah Nurkhasanah, Sapto Yuliani, Yuliana Purwaningsih, and Erwin Indriyanti. "Profiling of Active Compounds of Extract Ethanol, n-Hexane, Ethyl Acetate and Fraction Ethanol of Star Anise (Illicium verum Hook. f.) and Determination of Total Flavonoids, Total Phenolics and Their Potential as Antioxidants." Science and Technology Indonesia 8, no. 2 (April 15, 2023): 219–26. http://dx.doi.org/10.26554/sti.2023.8.2.219-226.
Анотація:
Profiling of chemical compounds on star anise extract and fractions showed the content and looked for active compounds. The main compounds in alkaloids, flavonoids, saponins, phenolics, and triterpenoid forms were identified based on phytochemical screening. FTIR and GC-MS analysis were used to purify the extract and fractions’ main compounds. After analyzing the main components of extract and fractions, a correlation was made between the total phenolic and flavonoid content. The total phenolic content was determined by adding folincalteau complexing solution converted to gallic acid equivalent (GAE), while the total flavonoid content was determined by AlCl3 complexing solution converted to Quercetin Equivalent (QE). The total phenolic yields for extract ethanol, n-hexane fraction, ethyl acetate fraction, and fraction ethanol were obtained at 106.45, 52.30, 93.46, and 148.97 mgGAE/g, respectively. Then the total flavonoid results were 107.45, 58.94, 148.99, 140.01 mgQE/g. The total content of phenolics and flavonoids illustrated the number of active compounds that have a role as free radical scavengers due to their group. Antioxidant activity was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) on extracts and fractions, with the best IC50 results obtained in the ethanol fraction 0.416 mg/mL.
4
Bajpai, Monika, Madhusudan S, and Sibi G. "Standardized method to extract phenolic compounds from Lagerstroemia speciosa L. (Jarul) for enhanced antioxidant activity." Journal of Applied and Natural Science 13, no. 3 (September 15, 2021): 1041–47. http://dx.doi.org/10.31018/jans.v13i3.2870.
Анотація:
Phenolic compounds contribute to the antioxidant property of plants and the efficient extraction of plant phenolics could enhance its antioxidant potential. Lagerstroemia speciosa (L.) Pers. has been investigated for its pharmacological activities, but comparing its antioxidant activities of phenolics derived from its various parts has a key role in developing natural antioxidants. This study was conducted to standardize the extraction of phenolics from leaves, pods and branches of L. speciosa plant, followed by determination of antioxidant activities of their solvent fractions. Phenolic compounds were extracted from the leaves, pods and branches under different parameters such as temperature, pH, type of solvent and volume of the solvent. The extracted phenolic compounds were subjected to solvent fractions and antioxidant assays were performed. Among the various extraction methods tested, the best method was 50% ethanol +1% HCl, refluxing temperature, 100 ml of solvent and 1 hour extraction time. The best solvent fractions were determined as NaHCO3 + ethyl acetate for pods and ethyl acetate alone for leaves and branches with extracted phenolics content of 150.2 mg/g, 136.2 mg/g and 82.9 mg/g, respectively. The chloroform fraction was best among the fractions with maximum ascorbic acid equivalent (ASE) in all the parts of L. speciosa tested. Ferrous ion chelating capacity indicated that butanol fraction had the highest chelation and the same was recorded in ferric ion chelating assay with an EC50 value of 28.2. Hydroxyl radical scavenging activity of the fractions indicated that NaHCO3 + EtOAc fraction of pods had potential activity. Thus, the phenolic compounds from L. speciosa are excellent sources for future investigation on potent natural antioxidant compounds.
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Mai Phuong, Thuy, Hong Do Thi, Mai Le Thi Tuyet та Hoa Le Thi Phuong. "VIETNAMESE Phellinus baumii FRUITING BODY, A POTENTIAL SOURCE OF ANTIOXIDANT AND α-AMYLASE INHIBITORY AGENTS". Journal of Science Natural Science 66, № 3 (жовтень 2021): 131–39. http://dx.doi.org/10.18173/2354-1059.2021-0054.
Анотація:
n-Hexane, ethyl acetate, and butanol fractions from methanol extract of Vietnamese Phellinus baumii fruiting body consisted of phenolics, flavonoids, and terpenoids. Ethyl acetate and butanol fractions showed a high level of total phenolics. Ethyl acetate fractions possessed the highest phenolic content (532.96 ± 19.95 mg GAE\g), accounting for approximately 53% fraction dry weight. Free radical DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging capacity of all fractions correlated with their total phenolic content. Ethyl acetate fraction exhibited the strongest capacity with an IC50 value of 0.059 mg\mL, equivalent to nearly 50% of ascorbic acid’s capacity. Its ferric reducing power was off more than half of quercetin and acid ascorbic at the concentration of 0.2 mg\mL. Ethyl acetate also had remarkable α-amylase inhibitory activity (IC50= 0.38 mg\mL). The results suggested P. baumii fruiting body as a potent source for antioxidative and α-amylase inhibitory compounds.
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Lin, Xue, Yousheng Shi, Pan Wen, Xiaoping Hu, and Lu Wang. "Free, Conjugated, and Bound Phenolics in Peel and Pulp from Four Wampee Varieties: Relationship between Phenolic Composition and Bio-Activities by Multivariate Analysis." Antioxidants 11, no. 9 (September 16, 2022): 1831. http://dx.doi.org/10.3390/antiox11091831.
Анотація:
Free, conjugated, and bound phenolic fractions of peel and pulp in four wampee varieties from South China were analyzed for their contents, composition, antioxidant capacities, and inhibitory activities against α-glucosidase. We found that there were significant differences in phenolic/flavonoid contents among diverse varieties and different parts (peel and pulp), and the contents were highest in the peel’s bound form. The results of UHPL-Q-Exactive HF-X and HPLC showed that chlorogenic acid, gentisic acid, and rutin were abundantly distributed over the three phenolic fractions in peel and pulp of all wampee samples, while isoquercitrin was the most abundant in the conjugated form of peel/pulp and myricetin had the richest content in the free form of peel/pulp. Wampee peel had stronger antioxidant capacities of ABTS+, DPPH, ·OH, and FRAP than the pulp, and the bound phenolic fraction of the peel/pulp had much higher antioxidant activities than FP and CP fractions. It is interesting that the same phenolic fraction of the wampee peel displayed roughly close IC50 values of α-glucosidase inhibition to those from the pulp samples. The relationship between individual phenolic and TPC/TFC/the bio-activities and the similarity among the free, conjugated, and bound phenolic fractions in peel and pulp samples were explored by using Pearson correlation analysis, principal component analysis, and hierarchical cluster analysis. This work provides a systematic and comprehensive comparison of the three phenolic fractions of diverse wampee varieties and different parts, and a rationale for applying phenolics from wampee fruits.
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Hikmawanti, Ni Putu Ermi, Agustin Yumita, Muhammad Rafiq, and Lusiana Lusiana. "Phenolics and Flavonoids Content of Wijaya Kusuma Leaves Fractions using Micro-plate Based Assay." Indonesian Journal of Pharmaceutical Science and Technology 10, no. 1 (February 28, 2023): 45. http://dx.doi.org/10.24198/ijpst.v10i1.35828.
Анотація:
Epiphyllum oxypetalum (DC.) or Wijaya Kusuma (Cactaceae) is an ornamental plant which is knownto contain polyphenol compounds. The purpose to determine the levels of total phenolic and flavonoidcompounds in the fractions of Wijaya Kusuma leaves using microplate-based assay. Each sample wasdetermined phenolic content with Folin-ciocalteu reagent and flavonoid content using AlCl3 on themicroplate. Absorption was measured using a microplate reader. Screening of DPPH radical scavengingactivity was identified using the TLC method. The results showed that the extract and fractions ofthe leaves of Wijaya Kusuma contained phenolic and flavonoid compounds. The ether fraction hadthe highest phenolic content (35,912±0,54776 mgGAE/g) and flavonoids (0,773±0,008 mgQE/g)compared to other fractions (ether>water>ethyl acetate fraction). There is one yellow spot with an Rfvalue of 0,85 in the ether fraction which is thought to be a compound capable of scavenging the DPPHradicals. The ether fraction of Wijaya Kusuma leaves has potential as a source of polyphenols withantioxidant activity. However, further research is needed to evaluate the antioxidant capacity in theether fraction of Wijaya Kusuma leaves.Keywords: Antioxidant, Epiphyllum oxypetalum (DC.) Haw, Flavonoids, Fraction, High-throughputMicroplate Assay, Phenolics.
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Kaboré, Kayaba, Crépin Ibingou Dibala, Hemayoro Sama, Mamounata Diao, Marius K. Somda, and Mamoudou H. Dicko. "Phenolic Content, Antioxidant Potential, and Antimicrobial Activity of Uvaria chamae (Annonaceae), a Food Plant from Burkina Faso." Biochemistry Research International 2024 (March 26, 2024): 1–8. http://dx.doi.org/10.1155/2024/1289859.
Анотація:
The study aimed to evaluate phenolic content and antioxidant and antibacterial potentials of the fractions of the hydroethanolic extract of Uvaria chamae leaves, a food plant from Burkina Faso. Thus, the hexane, dichloromethane, ethyl acetate, and butanol fractions of the hydroalcoholic extract after drying were used to determine phenolic compound content, antioxidant activity, and antimicrobial potential on strains of pathogenic bacteria responsible for food contamination. Phytochemical analyses were performed according to standardized methods, while antioxidant activity was evaluated by DPPH and FRAP methods. The antibacterial activity of the fractions was determined by diffusion and microdilution methods on the agar medium with gentamicin as a reference antibiotic. All the six strains, namely, Salmonella typhi ATCC 19430, Escherichia coli ATCC 8739, Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 9027, Bacillus cereus ATCC 13061, and Listeria monocytogenes ATCC 7644, were sensitive to the fractions tested. Minimum inhibitory concentrations ranged from 37 µg·mL−1 to 1.67 mg·mL−1, respectively, gentamicin and butanolic fractions, while minimum bactericidal concentrations of the fractions ranged from 0.037 to 2.500 mg·mL−1 depending on the bacterial strain. Antioxidant activity varied significantly between fractions. For DPPH free radical scavenging activity, the butanol fraction was the most active, with an IC50 of 280 μg/mL, while the lowest activity (705 μg/mL) was recorded by the hexane fraction. Those of trolox and ascorbic acid used as standards were 80 and 100 μg/mL, respectively. Ferric reducing power (FRAP) ranged from 0.34 to 0.40 mmol EAA/g extract for the hexanic and ethyl acetate fractions, respectively. Phenolic compound contents also varied significantly between fractions. Butanoic and ethyl acetate presented the best contents of total phenolics and flavonoids, respectively. Significant and positive correlations were also recorded between phenolics and antioxidant activities. The antibacterial and antioxidant activities of the active fractions would be related to their richness in bioactive compounds, including phenolic, which are powerful natural antioxidants. U. chamae leaf extracts could therefore be used as dietary supplements to boost the immune system and prevent bacterial infections.
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Menkovic, Nebojsa, Jelena Zivkovic, Katarina Savikin, Dejan Godjevac, and Gordana Zdunic. "Phenolic composition and free radical scavenging activity of wine produced from Serbian autochtonous grape variety Prokupac: A model approach." Journal of the Serbian Chemical Society 79, no. 1 (2014): 11–24. http://dx.doi.org/10.2298/jsc130511089m.
Анотація:
Phenolic compounds are very important quality parameters of wine because of their impact on colour, taste and health properties. The present study aimed to evaluate the general phenolic composition and free radical scavenging activity of aqueous and organic fractions obtained using liquid/liquid extractions from red wine produced from Serbian autochtonous grape variety Prokupac. Total phenolic contents in different fractions ranged from 48.22 to 289.12 mg GAE/g dry fraction. Phenolic acids (mainly hydroxycinnamic acids) and quercetin-3-glucuronide were the main components of the EtOAc fraction at pH 2.0; catechins, phenolic acids (mainly hydroxybenzoic acids) and quercetin were found in the EtOAc fraction at pH 7.0, while anthocyanins were identified in the aqueous residue after EtOAc extraction. The major anthocyanin extracted into aqueous fraction was malvidin-3-glucoside, while the most abundant non-anthocyanin phenolic compounds from organic fractions were ethyl gallate and trans-caftaric acid. Radical scavenging activity differed significantly among fractions and IC50 values were 138.58 ?g/ml for water fraction, 17.83 and 3.47 ?g/ml for EtOAc fractions at pH 2.0 and pH 7.0, respectively. As the EtOAc fractions were found to be more potent radical scavengers, it could be assumed that non-anthocyanin phenolic compounds were responsible for such activity in Prokupac wine.
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Zhou, Qingfeng, Jiexin Zhou, Xiaojing Liu, Yan-Bing Zhang, and Shengbao Cai. "Digestive Enzyme Inhibition of Different Phenolic Fractions and Main Phenolic Compounds of Ultra-High-Pressure-Treated Palm Fruits: Interaction and Molecular Docking Analyses." Journal of Food Quality 2020 (August 3, 2020): 1–10. http://dx.doi.org/10.1155/2020/8811597.
Анотація:
The purpose of the present work was to evaluate the inhibitory effects of different phenolic extracts from non- and ultra-high-pressure- (UHP-) treated palm fruits and their main phenolic compounds against pancreatic lipase and α-glucosidase and to further analyze the interaction and inhibitory mechanisms of two main phenolics (caffeic acid and catechin). Results showed that the free, esterified, and insoluble-bound phenolic fractions from the non- and UHP-treated fruits demonstrated good inhibitory effects towards two enzymes. The insoluble-bound phenolic fraction, regardless of UHP treatment, presented the strongest inhibitory capacities, and UHP treatment significantly upgraded the inhibitory effects of these phenolic fractions (lipase IC50 : 78.01 vs. 72.50 μg/mL; α-glucosidase IC50 : 76.42 vs. 64.51 μg/mL). Catechin and caffeic acid, main phenolic compounds detected in all phenolic fractions of the fruits, showed similar efficiencies on inhibiting the two enzymes, which were consistent with the findings observed by molecular docking analysis. Moreover, these two phenolic compounds exhibited a synergy effect on inhibiting pancreatic lipase and α-glucosidase at a relatively high combination concentration with the ratio of 1 : 1. Therefore, the present work may be helpful for further application of palm fruits as food supplements or nutraceuticals to control energy intake to improving some chronic metabolic diseases.
Дисертації з теми "Phenolic fractions":
1
Kalili, Kathithileni Martha. "Application of comprehensive 2-dimensional liquid chromatography for the analysis of complex phenolic fractions." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/2420.
Анотація:
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2009.ENGLISH ABSTRACT: The separation of apple, cocoa and green tea phenolic compounds by comprehensive 2-dimensional liquid chromatography (2-D-LC) has been studied. In the first dimension, phenolic compounds were separated according to polarity by hydrophilic interaction chromatography (HILIC) on a diol stationary phase with a mobile phase containing acetonitrile, methanol, acetic acid and water. Gradient reversed-phase (RP) LC using a C18 column with fluorescence detection was employed in the second dimension to separate compounds according to hydrophobicity. Compounds were identified using negative electrospray ionisation mass spectrometry (ESI-MS) coupled to both HILIC and RP separations. The coupling of HILIC and RP separations proved to be especially beneficial since this provided simultaneous information on both the polarity and hydrophobicity of phenolics. The low degree of correlation (r2 < 0.21) between the two LC modes afforded peak capacities in excess of 3000 for the off-line method. An on-line method was also developed utilizing a short, small particle-packed column to provide fast separation in the second dimension. A 1 mm i.d. column was used in the first dimension for the on-line system to reduce injection volumes onto the second dimension column. A significantly lower practical peak capacity was measured for the on-line system, due largely to the reduction in second dimension peak capacity. On the other hand, analysis could be performed in an automated fashion using the online system reducing the risk of sample alteration and guaranteeing better operation reliability and reproducibility. Especially the off-line comprehensive HILIC × RP-LC method developed demonstrated its utility in the analysis of various groups of phenolic compounds including proanthocyanidins, phenolic acids, flavonols and flavonol conjugates in a variety of natural products.
AFRIKAANSE OPSOMMING: Die skeiding van fenoliese komponente in appel, kakao en groen tee is deur middel van ‘comprehensive’ 2-dimensionele vloeistof chromatografie (2-D-LC) bestudeer. Hidrofiliese interaksie chromatografie (HILIC) is gebruik om die fenoliese komponente in die eerste dimensie te skei op grond van polariteit, deur gebruik te maak van ‘n diol stationêre fase en mobiele fase bestaande uit asetonitriel, metanol, asynsuur en water. ‘n Gradiënt omgekeerde fase (RP) LC analisie op ‘n C18 kolom met fluorosensie deteksie is in die tweede dimensie gebruik om fenole volgens hidrofobisiteit te skei. Negatiewe elektrosproei-ionisasie massa spektometrie (ESIMS) gekoppel aan HILIC en RP skeidings is gebruik vir identifikasie van fenole. Die koppeling van HILIC en RP skeidings veral voordelig deurdat dit gelyktydige informasie verskaf het oor die polariteit sowel as die hidrofobisiteit van die fenoliese komponente. Die lae graad van korrelasie (r2 < 0.21) tussen die twee LC metodes was verantwoordelik vir piek kapasiteite bo 3000 vir die af-lyn metode. ‘n Aanlyn metode was ontwikkel deur gebruik te maak van ‘n kort, klein partikel gepakte kolom om vinnige skeiding in die tweede dimensie te verseker. 1 mm i.d. kolom was gebruik in die eerste dimensie vir die aanlyn sisteem om die inspuit volume op die tweede dimensie kolom te verminder. Aansienlike laer praktiese piek kapasiteit was gemeet vir die aanlyn sisteem, grootliks toegeskryf aan die reduksie in die tweede dimensie piek kapasitiet. Aan die ander kant, analise kan geoutomatiseerd uitgevoer word deur gebruik te maak van die aanlyn sisteem, wat monster alterasie, beter betroubaarheid en reproduseerbaarhied verseker. Veral die ontwikkelde af-lyn ‘comprehensive’ HILIC × RP-LC metode toon demonstreerbare voordele vir die analiese van verskeie groepe fenoliese komponente, insluitende proantosianiede, fenoliese sure, flavonole en gekonjugeerde flavonole in ‘n verskeidenheid natuurlike produkte.
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Pedapati, S. C. S. H. "RECOVERY OF PHYTOCHEMICAL RICH FRACTIONS FROM WINEMAKING BYPRODUCTS FOR NOVEL FOOD APPLICATIONS." Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/244954.
Анотація:
The food industry is facing the significant challenge of developing new ingredients and foods addressing prevention of the major chronic diseases, while optimizing processing technologies in order to achieve a sustainable use of natural resources. Grape pomace, the byproduct of winemaking, is available on a large scale and is comprised of various compounds associated with potential health benefits. In this context, the overall PhD project aimed at developing an integrated strategy for recovery and reuse of value added fractions of winemaking byproducts in the food system.
Grape pomace samples, differing for the varieties and winemaking conditions were collected from winemaking processes and evaluated for valuable components, i.e, dietary fibre, total phenolics, soluble and insoluble proanthocyanidins (n-butanol/HCl assay), individual phenolic compouns (UPLC-DAD-MS), tocopherol and tocotrienol contents (HPLC with fluorimetric detection). This led to the design of a comprehensive recovery plan, bringing about the overall value of winemaking byproducts.
The aim of targeting a specific health functionality by grape phenolics was tackled in chapter 1, focused on their protective effects on hyperglyacemia induced damage. In the current scenario, prevention of diabetes complications is of utmost importance due to an upsurge in the prevalence of this disease among the world population (with an estimation of 300 million cases that could be registered by 2030). In vivo study has shown that phenolics can prevent the leading cause of hyperglycemia damage, i.e., non-enzymatic protein glycaton, most likely via radical scavenging, metal chelation and carbonyl trapping. However to target this effect, there is a need for phenolic fractions with high concentration and efficiency. An in vitro model system using fructose as glycating agent and bovine serum albumin as target was set up. The protective ability of grape skin phenolics was evaluated with both a novel methodological approach by 2D-SDS/IEF-PAGE and quantification of the formation of advanced glycation end-products by fluorescence measurements. Structural modifications of BSA upon glycation, as evidenced by changes in pI and Mr were found to be inhibited by the grape skin extracts. The antiglycation activity ranking was: quercetin-3-O-glucoside > malvidin-3-O-glucoside > catechin > procyanidin A2 >> aminoguanidine (reference drug). Despite variability in phenolic content (in the range 4.6-53.6 g gallic acid equivalents (GAE)/kg) and composition among grape skin extracts, upon equalization of the phenolic content, similar antiglycation properties were observed. Grape skins (I50 in the range 9.2-20 µg GAE/mL) were more efficient than the commercial nutraceutical products Leucoselect® (I50 38 µg GAE/mL) and Pycnogenol® (I50 34 µg GAE/mL) and hence could provide cost-effective antiglycation agents, to be used either as food ingredients or as nutraceutical preparations.
The task of designing new foods by the incorporation of grape skins, which can deliver both dietary fibers and phenolics, was examined in chapter 2. Grape skins have been proposed as ingredients for “solid” or “gel-like” foods, but knowledge on their possible application in complex food fluids that could represent low caloric vehicle for value added ingredients is lacking. Hence, a tomato puree added with grape skins was studied as a model application and a production process was designed to increase potential health benefit of this product with maximum consumers’ liking.
To optimize grape skin ingredient incorporation in tomato puree, six formulations (3% dietary fibre and ~ 0.7% proanthocyanidins) varying in the particle size (assessed by a laser granulometer) were considered in parallel. Stabilization was performed by either an intensive autoclave treatment or an optimized microwave treatment achieving six decimal reductions of the target microorganism (Alicylobacillus acidoterrestris). Upon processing, major changes in the fortified purees were both decrease in proanthocyanidin solubility (by ~ 40%, probably due to interaction with tomato protein) and decrease in flavonol glycosides with parallel increase of their aglycones. However, phenolic contents, reducing capacity and antiglycation activity remained ~ 3 times higher in all the fortified purees than in the controls. These chemical parameters were related to particle size distribution, since with decreasing surface-weighed mean diameter, d(3,2), proanthocyanidin solubility increased. The addition of grape skins played a major role on the color (measured by Hunter colorimeter), storage (G’) and loss (G’’) moduli, complex viscosity (studied by means of dynamic oscillatory measurements) and Bostwick consistency of the formulations. A sensory test based on consumers’ preference disclosed that the formulation having the maximum appreciation was that incorporated with the smallest particle sizes. Liking ratings were found to be inversely correlated to the volume-weighted mean diameter, d(4,3) values. The overall results obtained from this methodological approach represent a basis for the optimization of fibrous byproducts incorporation into complex food fluids.
Besides use of grape skins as source of antiglycation and fortifying agents, utilization of grape seeds which forms a major part of the pomace is of importance in the recovery strategy. Chapter 3 focused on assessment of supercritical-CO2 (SC-CO2) extraction for the recovery of oil, as a “green technology” alternative to n-hexane extraction and mechanical extraction. Extraction by SC-CO2 can be a sustainable technology, if the process is carried out at optimum operating conditions ensuring high yield and in a sufficient extractor volume. The breakeven point, which makes the process economically sustainable, is also linked to the quality of the oil obtained. Besides oil, the defatted seeds rich in phenolics were also considered as a relevant co-product of this process. Hence, grape seed phenolics were studied as inhibitors of starch digestion enzymes, which is the first relevant step to control blood glucose level. Extraction by SC-CO2 provided the same oil yield as that of n-hexane extraction (10.1-16.6 g oil/100g seeds). 1H-NMR spectra showed that diacylglycerols and oxidized lipids were present only in trace amounts. The levels of tocols were in the range: 355-559 mg/kg higher than those of the oils obtained by n-hexane extraction and similar to those of oils obtained by mechanical extraction. Tocotrienols, which possess high antioxidant and antiproliferative properties were the prominent compounds present. In the defatted grape seeds, levels of phenolics one order of magnitude higher than those of the grape skins were observed (49-277 g GAE/kg). The anthocyanin rich grape seed extracts showed the highest inhibitory effectiveness towards α-glucosidase (I50 47 µg GAE/mL ~ half than that of the drug acarbose). Inhibitory effectiveness towards α-amylase activity was similar among grape varieties, with I50 values comparable to that of acarbose and correlated to proanthocyanidin contents.
The overall results could pave the way for recovery and value-addition of winemaking byproducts for food and nutraceutical uses, including grape skins as a source of antiglycation agents or as dietary antioxidant fibre, grape seeds as a source of tocol rich oil, defatted grape seeds as a source of phenolics.
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Ndolo, Victoria Uchizi. "Characterisation of chemical components in manually isolated aleurone and associated layers from maize, wheat and barley kernels." Elsevier, 2013. http://hdl.handle.net/1993/30914.
Анотація:
Health benefits related to consumption of whole grains have been attributed in part to phytochemical and micronutrient composition. Understanding the composition, structure and distribution of these components in different cereal grains is of potential importance in aiding the selection of whole grains and their processed fractions for inclusion in the diet, and as ingredients in development of new food products. The aim of this research was to characterise the chemical components in the botanical fractions of yellow corn, barley, wheat. Manual separation, a tedious and laborious technique that yields pure fractions, suitable for compositional analysis, was used to separate whole grains into pericarp, aleurone layer, germ and endosperm fractions. Component identification and quantification of tissue components was accomplished by several techniques. The study also explored the possibility of using spectral characteristics fluorescence intensity values to provide rapid estimates of the concentrations and distribution of ferulic acid (FA), a major phenolic compound in cereal grains. While composition of phenolic acids and carotenoids was similar, the distribution was significantly different (P < 0.05) among cereal types and grain fractions. Phenolic acids were concentrated in pericarp and aleurone fractions, followed by the germ and the endosperm had the lowest levels. Yellow corn exhibited the highest values. Carotenoids, lutein and zeaxanthin were concentrated in the germ and aleurone layer of wheat and barley while in yellow corn it was in the endosperm and aleurone layer. This is the first study to report on carotenoid composition of aleurone fractions. Mineral elements, thiamine and niacin were higher in wheat aleurone than in purple barley and yellow corn aleurone layers. These findings suggest that yellow corn aleurone layers have potential as a functional food ingredient despite the low micronutrient content. A positive, significant correlation (r= 0.421, p < 0.0001) was found between fluorescence intensity values and ferulic acid concentration. Thus, fluorescence intensity profiles are a promising approach for rapid assessment of FA concentration in grain in-situ. This work has provided information that would act as a database for selection of cereal fractions and guide the miller to obtain grain fractions with enriched levels of phytochemicals and micronutrients.February 2016
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Le, Thi Tuong. "Purification et propriétés anti-inflammatoires et anti-oxydantes des fractions phénoliques issues de coproduits de production d'isolats protéiques d'oleoproteagineux." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0270.
Анотація:
Le colza et le tournesol sont les plantes oléagineuses les plus cultivées en Europe en général, et en France en particulier. Certains industriels se concentrent actuellement sur le développement de procédés industriels d'extraction/purification des protéines des tourteaux de ces deux végétaux. Ces procédés génèrent des coproduits qui sont des effluents aqueux salins riches en composés phénoliques tels que l'acide cholorgénique (CGA, pour le tournesol) et la sinapine (SP, pour le colza). La capture de ces composés phénoliques qui peuvent agir comme anti-oxydants naturels et/ou anti-inflammatoires en nutrition – santé constitue donc une voie de valorisation prometteuse. Les principaux objectifs de ce travail étaient les suivants 1) caractériser et identifier les composés phénoliques des sous-produits d'isolat de protéines à partir de la SFM et de la RSM ; 2) choisir les meilleures résines macroporeuses et étudier le mécanisme d'adsorption des composés phénoliques; 3) optimiser les conditions dans la colonne d’adsorption des composés phénoliques; et 4) évaluer les activités biologiques des fractions phénoliques obtenues, notamment les propriétés antioxydantes et anti-inflammatoires. Par différentes méthodes analytiques, nous avons déterminé que les effluents liquides étaient constitués de composés phénoliques, d'acides aminés, d'hydrates de carbone et de sel, qui ont un poids moléculaire faible et qui peuvent facilement passer à travers une membrane UF/DF. Tous les composés phénoliques ont été identifiés par analyse HPLC et HPLC-ESI-MS, en comparaison avec des standards. Le CGA est le principal composé phénolique des effluents tournesol. Le principal composé phénolique des effluents colza est la SP. Contrairement au tournesol, ils contiennent aussi de nombreux autres composés mineurs. L'adsorption/désorption des composés phénoliques de tournesol et de colza a été évaluée à l'aide de différentes résines macroporeuses, notamment XAD4, XAD7, XAD16, XAD1180 et HP20. Nous avons constaté que tous les composés phénoliques s'adsorbaient facilement sur les résines. Les résines XAD7 et XAD16 ont montré les meilleures propriétés d'adsorption/désorption dans les effluents liquides de tournesol et de colza, respectivement. Les résultats ont montré que l'adsorption de tous les composés phénoliques suit un modèle. Les isothermes d’adsorption suivent un modèle de Langmuir. Selon les paramètres thermodynamiques déterminés, le processus d'adsorption, est dans tous les cas physique et est exothermique. La condition optimale pour l'adsorption sur colonne a été déterminée sur les résines sélectionnées par planification expérimentale et optimisation multicritère. Une méthodologie d'optimisation multicritères basée sur des plans d'expériences a montré que les conditions optimales étaient un débit d'adsorption de 15 BV/h à un pH de 2,7 pour le CGA de la SFM. De l’autre côté, un débit d'adsorption de 13,3 BV/h et un pH compris entre 2 et 5 étaient les conditions optimales pour la sinapine du RSM. Des solutions d’éthanol (50% (v/v) pour l'acide chlorogénique, 70% (v/v) pour la sinapine ont été utilisées pour la desorption. Ces approches ont permis de produire avec succès les fractions phénoliques pour des activités biologiques telles que l'antioxydation et l'anti-inflammation. La fraction phénolique a montré une capacité antioxydante plus élevée que la vitamine C dans le test ABTS (IC50/fractions phénoliques < IC50 vitamine C, p < 0,05). Il a en outre été discuté si les fractions phénoliques obtenues dans le cadre de ce projet présentaient également un effet inflammatoire. La fraction tournesol (CGA) a efficacement inhibé la production de TNF-α, qui est un marqueur pro-inflammatoire lorsqu'un échantillon est traité avec du LPS. Cependant, les fractions colza n'étaient pas efficaces contre les médiateurs pro-inflammatoires. Aucune des fractions n’a montré de cytotoxicitéRapeseed and sunflower are the most cultivated oilseed plants in Europe in general, and in France in particular. Some industrialists are currently focusing on the development of industrial processes for the extraction/purification of proteins from the oil cakes of these two plants. These processes generate co-products which are saline aqueous effluents rich in phenolic compounds such as cholorgenic acid (CGA, for sunflower) and sinapine (SP, for rapeseed). The capture of these phenolic compounds, which can act as natural antioxidants and/or anti-inflammatory agents in nutrition and health, is therefore a promising way of valorization. The main objectives of this work were: 1) to characterize and identify the phenolic compounds of protein isolate by-products from SFM and RSM; 2) to select the best macroporous resins and to study the adsorption mechanism of phenolic compounds; 3) to optimize the conditions in the phenolic compounds adsorption column; and 4) to evaluate the biological activities of the obtained phenolic fractions, especially the antioxidant and anti-inflammatory properties.By different analytical methods, we determined that the liquid effluents consisted of phenolic compounds, amino acids, carbohydrates, and salt, which have a low molecular weight and can easily pass through a UF/DF membrane. All phenolic compounds were identified by HPLC and HPLC-ESI-MS analysis in comparison with standards. CGA is the main phenolic compound in the sunflower effluent. The main phenolic compound of rapeseed effluents is MS. Unlike sunflower, they also contain many other minor compounds. The adsorption/desorption of sunflower and rapeseed phenolic compounds was evaluated using different macroporous resins including XAD4, XAD7, XAD16, XAD1180 and HP20. We found that all phenolic compounds adsorbed readily onto the resins. XAD7 and XAD16 resins showed the best adsorption/desorption properties in sunflower and rapeseed liquid effluents, respectively. The results showed that the adsorption of all phenolic compounds follows a Langmuir model. According to the determined thermodynamic parameters, the adsorption process, is in all cases physical and is exothermic.The optimal condition for column adsorption was determined on the selected resins by experimental planning and multicriteria optimization. A multicriteria optimization methodology based on design of experiments showed the optimal conditions were adsorption flow rate of 15 BV/h at pH 2.7 for CGA from SFM. Meanwhile, adsorption flow rate of 13.3 BV/h and at pH ranging from 2 to 5 were the optimal conditions for sinapine from RSM. Ethanol solutions 50% (v/v) for chlorogenic acid, 70% (v/v) for sinapine were used for desorption.These approaches successfully produced the phenolic fractions for biological activities such as antioxidation and anti-inflammation. Phenolic fraction showed a higher antioxidant capacity than vitamin C in DPPH and ABTS assays (IC50/phenolic fractions < IC50 vitamin C, p < 0.05. In addition, it was discussed whether the phenolic fractions obtained in this project also showed an inflammatory effect. The sunflower fraction (CGA) effectively inhibited the production of TNF-α, which is a pro-inflammatory marker when a sample is treated with LPS. However, the rapeseed fractions were not effective against proinflammatory mediators. None of the fractions showed cytotoxicity
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Lindhorst, Kathleen. "Antioxidant activity of phenolic fraction of plant products ingested by the Maasai." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0006/MQ44206.pdf.
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Aleksandra, Novaković. "Biopotencijal autohtonih gljiva u funkciji nutraceutika." Phd thesis, Univerzitet u Novom Sadu, Prirodno-matematički fakultet u Novom Sadu, 2015. https://www.cris.uns.ac.rs/record.jsf?recordId=95449&source=NDLTD&language=en.
Анотація:
Karakterizacija ekstrakata plodnih tela devet autohtonih vrsta gljiva pripadnika razdela Basidiomycota obuhvatila je preliminarno ispitivanje hemijskog sastava i ispitivanje biološke aktivnosti. Primenom HPLC‐MS/MS i GC-FID tehnike detektovan je i određen sadržaj fenolnih jedinjenja i metil estara masnih kiselina. Primenom tehnike elektroforeze na mikročipu ("LAB‐ON‐A‐CHIP" kapilarnom elektroforezom) izvršena je karakterizacija proteinskih frakcija u odabranim vrstama gljiva. Antioksidantna aktivnost (sposobnost neutralizacije slobodnih radikala, redukcioni potencijal), sadržaj ukupnih fenola i flavonoida vodenih i etanolnih ekstrakata ispitan je primenom spektrofotometrijskih metoda. Antimikrobna aktivnost metanolnog i heksanskog ekstrakta ispitana je na Gram‐pozitivnim i Gram–negativnim bakterijskim sojevima. Efekat etanolnih i vodenih ekstrakata odabranih vrsta gljiva na rast ćelijske linije MCF7 (humani adenokarcinom dojke pozitivan na estrogenske i progesteronske receptore), ispitan je MTT i SRB testom, dok je efekat frakcija ispitan primenom MTT testa. Sumarno, ukupni biopotencijal ispitivanih vrsta na osnovu sprovedenih analiza hemijske karakterizacije i bioloških testova upućuju opravdanost hipoteze da su odabrane vrste potencijalni izvori nutraceutika. Svakako je potrebno i neophodno nastaviti dalja istraživanja ovih vrsta.Characterization of extracts of fruiting bodies of nine native species of mushrooms members of section Basidiomycota included preliminary testing of chemical composition and biological activity. Using HPLC‐MS / MS and GC‐FID techniques the content of phenolic compounds and fatty acid methyl esters has been detected and determined. By applying the techniques of electrophoresis on microchip ("LAB‐ON‐A‐CHIP" capillary electrophoresis) characterization of protein fractions in selected types of mushrooms has been performed. The antioxidant activity (the ability of neutralizing free radicals, reducing potential), the contents of total phenols and flavonoids of water and ethanol extracts has been tested using the spectrophotometric method. The antimicrobial activity of methanol and hexane extracts was tested against Gram‐positive and Gram‐negative bacterial strains. The effect of ethanol and aqueous extracts of selected fungi species on the growth of the cell line MCF7 (human breast adenocarcinoma positive for estrogen and progesterone receptors), has been examined using MTT and SRB assay, while the effect of the fractions has been tested by using the MTT assay. In summary, the overall biological potential of the examined species based on results for chemical and biological characterization tests (anti‐oxidative, antimicrobial and anti‐proliferative) indicate the justifiability of the hypothesis that examined species of mushrooms are potential sources of nutraceuticals. It is certainly needed and necessary to continue further research of these species.
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Sukhbaatar, Badamkhand. "SEPARATION OF ORGANIC ACIDS AND LIGNIN FRACTION FROM BIO-OIL AND USE OF LIGNIN FRACTION IN PHENOL-FORMALDEHYDE WOOD ADHESIVE RESIN." MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-06062008-155306/.
Анотація:
Bio-oil produced from biomass by the fast pyrolysis method is promising as a renewable fuel and as sources of industrial chemicals. In this study, lower cost separation methods of organic acids such as acetic and formic acids and pyrolytic lignin fraction present in bio-oil were investigated to provide basic data needed for future industrial production procedures. The calcium oxide method and a quaternary ammonium anion-exchange resin method were studied to separate organic acids as respective salts and the methanol-and-water method was studied to separate the water-insoluble pyrolytic lignin fraction. The calcium oxide and anion-exchange methods were shown to be effective in separation of organic acids, although further improvements would be needed. The pyrolytic lignin separation method was also shown to give lignin fraction that is effective for up to 40% replacement of phenol in the oriented strand board core-layer binder PF resins.
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Демчук, Юрій Ярославович. "Бітуми, модифіковані смолами, одержаними з фенольної фракції кам’яновугільної смоли". Diss., Національний університет "Львівська політехніка", 2021. https://ena.lpnu.ua/handle/ntb/56146.
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Ramos, Patrícia Alexandra Bogango. "Chemical characterization and evaluation of biological activity of Cynara cardunculus extractable compounds." Doctoral thesis, Universidade de Aveiro, 2015. http://hdl.handle.net/10773/15686.
Анотація:
Doutoramento em QuímicaThe Mediterranean species Cynara cardunculus L. is recognized in the traditional medicine, for their hepatoprotective and choleretic effects. Biomass of C. cardunculus L. var. altilis (DC), or cultivated cardoon, may be explored not only for the production of energy and pulp fibers, but also for the extraction of bioactive compounds. The chemical characterization of extractable components, namely terpenic and phenolic compounds, may valorize the cultivated cardoon plantation, due to their antioxidant, antitumoral and antimicrobial activities. In this study, the chemical composition of lipophilic and phenolic fractions of C. cardunculus L. var. altilis (DC), cultivated in the south of Portugal (Baixo Alentejo region) was characterized in detail, intending the integral valorization of its biomass. The biological activity of cultivated cardoon extracts was evaluated in terms of antioxidant, human tumor cell antiproliferative and antibacterial effects. Gas chromatography-mass spectrometry (GC-MS) was used for the chemical analysis of lipophilic compounds. Sixty-five lipophilic compounds were identified, from which 1 sesquiterpene lactone and 4 pentacyclic triterpenes were described, for the first time, as cultivated cardoon components, such as: deacylcynaropicrin, acetates of β- and α-amyrin, lupenyl acetate and ψ-taraxasteryl acetate. Sesquiterpene lactones were the major family of lipophilic components of leaves (≈94.5 g/kg), mostly represented by cynaropicrin (≈87.4 g/kg). Pentacyclic triterpenes were also detected, in considerably high contents, in the remaining parts of cultivated cardoon, especially in the florets (≈27.5 g/kg). Taraxasteryl acetate was the main pentacyclic triterpene (≈8.9 g/kg in florets). High pressure liquid chromatography-mass spectrometry (HPLC-MS) was utilized for the chemical analysis of phenolic compounds. Among the identified 28 phenolic compounds, eriodictyol hexoside was reported for the first time as C. cardunculus L. component, and 6 as cultivated cardoon components, namely 1,4-di-O-caffeoylquinic acid, naringenin 7-O-glucoside, naringenin rutinoside, naringenin, luteolin acetylhexoside and apigenin acetylhexoside. The highest content of the identified phenolic compounds was observed in the florets (≈12.6 g/kg). Stalks outer part contained the highest hydroxycinnamic acids abundance (≈10.3 g/kg), and florets presented the highest flavonoids content (≈10.3 g/kg). The antioxidant activity of phenolic fraction was examined through 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Stalks outer part, and receptacles and bracts extracts demonstrated the highest antioxidant effect on DPPH (IC50 of 34.35 μg/mL and 35.25 μg/mL, respectively). (cont.) abstract (cont.) The DPPH scavenging effect was linearly correlated with the total contents of hydroxycinnamic acids (r = -0.990). The in vitro antiproliferative activity of cultivated cardoon lipophilic and phenolic extracts was evaluated on a human tumor cells line of triple-negative breast cancer (MDA-MB-231), one of the most refractory human cancers to conventional therapeutics. After 48 h of exposition, leaves lipophilic extract showed higher inhibitory effect (IC50 = 10.39 μg/mL) than florets lipophilic extract (IC50 = 315.22 μg/mL), upon MDA-MB-231 cellular viability. Pure compound of cynaropicrin, representative of the main compound identified in leaves lipophilic extract, also prevented the cell proliferation of MDA-MB-231 (IC50 = 17.86 μM). MDA-MB-231 cells were much more resistant to the 48 h- treatment with phenolic extracts of stalks outer part (IC50 = 3341.20 μg/mL) and florets (IC50 > 4500 μg/mL), and also with the pure compound of 1,5-di-O-caffeoylquinic acid (IC50 = 1741.69 μM). MDA-MB-231 cells were exposed, for 48 h, to the respective IC50 concentrations of leaves lipophilic extract and pure compound of cynaropicrin, in order to understand their ability in modelling cellular responses, and consequently important potentially signaling pathways for the cellular viability decrease. Leaves lipophilic extract increased the caspase-3 enzymatic activity, contrarily to pure compound of cynaropicrin. Additionally, leaves lipophilic extract and pure compound of cynaropicrin caused G2 cell cycle arrest, possibly by upregulating the p21Waf1/Cip1 and the accumulation of phospho-Tyr15-CDK1 and cyclin B1. The inhibitory effects of leaves lipophilic extract and cynaropicrin pure compound, against the MDA-MB-231 cell proliferation, may also be related to the downregulation of phospho-Ser473-Akt. The antibacterial activity of cultivated cardoon lipophilic and phenolic extracts was assessed, for the first time, on two multidrug-resistant bacteria, such as the Gram-negative Pseudomonas aeruginosa PAO1 and the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA), two of the main bacteria responsible for health care-associated infections. Accordingly, the minimum inhibitory concentrations (MIC) were determined. Lipophilic and phenolic extracts of florets did not have antibacterial activity on P. aeruginosa PAO1 and MRSA (MIC > 2048 μg/mL). Leaves lipophilic extract did not prevent the P. aeruginosa PAO1 growth, but pure compound of cynaropicrin was slightly active (MIC = 2048 μg/mL). Leaves lipophilic extract and pure compound of cynaropicrin blocked MRSA growth (MIC of 1024 and 256 μg/mL, respectively). The scientific knowledge revealed in this thesis, either by the chemical viewpoint, or by the biological viewpoint, contributes for the valorization of C. cardunculus L. var. altilis (DC) biomass. Cultivated cardoon has potential to be exploited as source of bioactive compounds, in conciliation with other valorization pathways, and Portuguese traditional cheeses manufacturing.
A espécie mediterrânica Cynara cardunculus L. é reconhecida na medicina tradicional, pelos seus efeitos hepatoprotetor e colerético. A biomassa de C. cardunculus L. var. altilis (DC), ou cardo cultivado, poderá ser explorada não só para a produção de energia e fibras de pasta de papel, mas também para a extração de compostos bioativos. A caracterização química dos componentes extratáveis, nomeadamente os compostos terpénicos e fenólicos, poderá valorizar a plantação de cardo cultivado, dadas as suas atividades antioxidante, antitumoral e antimicrobiana. Neste estudo, a composição química das frações lipofílica e fenólica de C. cardunculus L. var. altilis (DC), cultivado no sul de Portugal (região do Baixo Alentejo), foi caracterizada em detalhe, com vista à valorização integral da sua biomassa. A atividade biológica dos extratos de cardo cultivado foi avaliada em termos de efeitos antioxidante, antiproliferativa em células humanas tumorais, e antibacteriano. A análise química dos compostos lipofílicos foi realizada por cromatografia em fase gasosa acoplada à espectrometria de massa (GC-MS). Identificaram-se 65 compostos lipofílicos, dos quais 1 lactona sesquiterpénica e 4 triterpenos pentacíclicos foram descritos, pela primeira vez, como componentes do cardo cultivado, tais como: desacilcinaropicrina, acetatos de β- e α-amirina, acetato de lupenilo e acetato de ψ-taraxasterilo. As lactonas sesquiterpénicas foram a principal família de compostos lipofílicos das folhas (≈94,5 g/kg), maioritariamente representadas pela cinaropicrina (≈87,4 g/kg). Os triterpenos pentacíclicos foram também detetados, em teores consideravelmente elevados, nas restantes partes do cardo cultivado, em especial nos floretos (≈27,5 g/kg). O acetato de taraxasterilo foi o triterpeno pentacíclico maioritário (≈8,9 g/kg nos floretos). Para a análise química dos compostos fenólicos foi utilizada a cromatografia líquida de alta resolução acoplada à espectrometria de massa (HPLC-MS). Entre os 28 compostos fenólicos identificados, o erioditiol hexósido foi descrito pela primeira vez como componente de C. cardunculus L., e 6 como componentes do cardo cultivado, nomeadamente ácido 1,4-di-O-cafeoilquínico, naringenina 7-O-glucósido, naringenina rutinósido, naringenina, luteolina acetil-hexósido e apigenina acetil-hexósido. A concentração mais alta de compostos fenólicos identificados foi observada nos floretos (≈12,6 g/kg). A parte externa dos caules continha o maior teor em ácidos hidroxicinâmicos (≈10,3 g/kg), e os floretos apresentaram o maior teor em flavonoides (≈10,3 g/kg). A atividade antioxidante da fração fenólica foi examinada face ao radical livre 2,2-difenil-1-picril-hidrazilo (DPPH). Os extratos da parte externa do caule, e dos recetáculos e brácteas demonstraram o maior efeito antioxidante, face ao DPPH (IC50 de 34,35 μg/mL e 35,25 μg/mL, respetivamente). (cont.) resumo (cont.) A atividade antioxidante face ao DPPH foi correlacionada linearmente com a concentração total de ácidos hidroxicinâmicos (r = -0.990). A atividade antiproliferativa in vitro dos extratos lipofílicos e fenólicos de cardo cultivado foi avaliada numa linha de células tumorais humanas de cancro da mama de fenótipo triplo-negativo (MDA-MB-231), um dos tipos de cancro humano mais refratários às terapêuticas convencionais. Após 48 h de exposição, o efeito inibitório do extrato lipofílico das folhas (IC50 = 10,39 μg/mL) foi superior ao do extrato lipofílico dos floretos (IC50 = 315,22 μg/mL), sobre a viabilidade celular de MDA-MB-231. O composto puro da cinaropicrina, representativo do composto maioritário identificado no extrato lipofílico das folhas, também inibiu a proliferação das células MDA-MB-231 (IC50 = 17,86 μM). As células MDA-MB-231 foram muito mais resistentes, ao tratamento de 48 h, com os extratos fenólicos da parte externa dos caules (IC50 = 3341,20 μg/mL) e dos floretos (IC50 > 4500 μg/mL), e também com o composto puro do ácido 1,5-di-O-cafeoilquínico (IC50 = 1741,69 μM). As células MDA-MB-231 foram expostas, durante 48 h, às respetivas concentrações de IC50 do extrato lipofílico das folhas e do composto puro da cinaropicrina, de modo a perceber a sua capacidade em modelar respostas celulares, e consequentemente potenciais vias de sinalização importantes para o decréscimo da viabilidade celular. O extrato lipofílico das folhas aumentou a atividade enzimática da caspase-3, ao contrário do composto puro da cinaropicrina. Além disso, o extrato lipofílico das folhas e o composto puro da cinaropicrina causaram paragem do ciclo celular na fase G2, possivelmente através do aumento da expressão proteica de p21Waf1/Cip1 e da acumulação das proteínas fosfo-Tyr15-CDK1 e ciclina B1. Os efeitos inibitórios do extrato lipofílico das folhas e do composto puro da cinaropicrina, contra a proliferação das células MDA-MB-231, poderão também estar relacionados com a diminuição da expressão proteica da fosfo-Ser473-Akt. A atividade antibacteriana dos extratos lipofílicos e fenólicos de cardo cultivado foi avaliada, pela primeira vez, sobre duas bactérias multirresistentes, tais como a bactéria Gram-negativa Pseudomonas aeruginosa PAO1 e a bactéria Gram-positiva Staphylococcus aureus resistente à meticilina (MRSA), duas das principais bactérias responsáveis pelas infeções associadas aos cuidados de saúde. Para tal, determinaram-se as concentrações inibitórias mínimas (MIC). Os extratos lipofílicos e fenólicos dos floretos não revelaram atividade antibacteriana contra P. aeruginosa PAO1 e MRSA (MIC > 2048 μg/mL). O extrato lipofílico das folhas não inibiu o crescimento de P. aeruginosa PAO1, mas o composto puro da cinaropicrina foi ligeiramente ativo (CIM = 2048 μg/mL). O extrato lipofílico das folhas e o padrão puro da cinaropicrina bloquearam o crescimento de MRSA (MIC de 1024 e 256 μg/mL, respetivamente). O conhecimento científico revelado nesta tese, quer do ponto de vista químico, quer do ponto de vista biológico, contribui para a valorização da biomassa de C. cardunculus L. var. altilis (DC). O cardo cultivado tem potencial para ser explorado como fonte de compostos bioativos, em conciliação com outras vias de valorização, e a produção de queijos tradicionais portugueses.
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Snipes, Lauren. "Inhibition of human aldose reductase by high phenolic and high anti-oxidative extracts of muscadine grape fractions." 2006. http://purl.galileo.usg.edu/uga%5Fetd/snipes%5Flauren%5Fe%5F200608%5Fms.
Частини книг з теми "Phenolic fractions":
1
Londonkar, Ramesh, and Maithilee Kesralikar. "In Vitro Anticancer Screening of Methanolic Extract of Stachytarpheta Mutabilis." In Proceedings of the Conference BioSangam 2022: Emerging Trends in Biotechnology (BIOSANGAM 2022), 188–204. Dordrecht: Atlantis Press International BV, 2022. http://dx.doi.org/10.2991/978-94-6463-020-6_19.
Анотація:
AbstractIn therapeutic plants, phytochemicals are found in abundance. A family of verbena known as vervain (verbenaceae) consists of over 100 genera and nearly 2600 species. Among the Verbenaceae family is Stachytarpheta, a green perennial herb. The species is being examined in this study for its phytochemical, antioxidant, and anti-inflammatory properties. Stachytarpheta mutabilis methanol extracts were studied for their phytochemical screening, antimicrobial, anti-inflammatory, and anticancerous effects in the current study. Phytochemical study revealed the presence of alkaloids, flavonoids, glycosides, steroids, tannins, carbohydrates, and saponins, among other phytoconstituents. One fungus, Aspergillus niger, Staphylococcus aureus, and Bacillus subtilis, as well as four-gram (+) pathogens, including Staphylococcus aureus and Bacillus subtilis, and two gram (-) pathogens, including Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, and Klebsiella pneumoniae, were disc diffusion tested for antibacterial activity. The nitric oxide scavenging assay was used to test for anti-inflammatory efficacy in vitro. DPPH, ABTS, and total antioxidant tests were used to evaluate antioxidant activity. Analyses such as TLC, GC-MS, and were performed as per common procedure. A nitric oxide scavenging experiment was utilised to determine the anti-inflammatory properties of the drug in vitro. Tests for antioxidant activity were conducted using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)), and total antioxidant tests. MTT (3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) analysis has been used to do anticancer screening. Extracts from Stachytarpheta mutabilis were found to include flavonoids, tannins and phenolic compounds as well as terpenoids and steroids in their phytochemical analysis. Squalene, octadecanal, and butan-1-one were found in the GC-MS study as were thirty other bioactive chemicals such as 4-isopropylcinnamic acid and octadecanoic acid. The methanolic fractions of plant extracts were shown to be effective against all bacteria. Anti-inflammatory and antioxidant experiments performed in the lab revealed the compounds’ potent inhibition activity. Analysis of the GC-MS data revealed the existence of thirty distinct components. MTT assay on the extract revealed anticancer activity. The data shows that the methanolic extract has a significant properties. Stachytarpheta mutabilis has therapeutic value and other pharmaceutical qualities may be assessed as a result of these results, which support the traditional usage of folk medicine as well.
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Soidrou, Said H., Dalila Bousta, Mohammed Lachkar, Said O. S. Hassane, Amal El Youbi-Hamsas, Latifa El Mansouri, Jamal Benjilali, Hanane El-Hajaji, and Abdellah Farah. "Immunomodulatory Activity of Phenolic Fraction from Piper Borbonense and Cassytha Filiformis Growing in Comoros Islands." In Chemistry: The Key to our Sustainable Future, 105–12. Dordrecht: Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7389-9_7.
3
Desbene, P.-L., C. Rony, B. Yver, B. Desmazieres, and J.-C. Jacquier. "Analytical Study of Biomass Pyrolysis Oils. I- Analysis of the Phenolic Fraction by High Performance Micellar Electrokinetic Chromatography." In Advances in Thermochemical Biomass Conversion, 922–37. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1336-6_71.
4
Gómez-Cordovés, C., B. Bartolomé, W. Vieira, and V. M. Virador. "Antioxidant Properties of Wine Phenolic Fractions." In Dietary Anticarcinogens and Antimutagens, 238–41. Elsevier, 2000. http://dx.doi.org/10.1533/9781845698188.5.238.
5
Sameh, Boudiba, Hanini Karima, Boudiba Louiza, Saouane Izzeddine, and Benahmed Merzoug. "Mathematical Relationship Based on Experimental Data, for Corrosion Inhibition Mechanism of Phenolic Compounds Obtained from Echium italicum L." In Phenolic Compounds [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99616.
Анотація:
We highlight in this chapter the corrosion protection using phenolic extract. The building of mathematical models using experimental results obtained from the investigation of phenolic molecules or fractions extracted from Echium italicum L., used as corrosion inhibitors is one of the new trends in the study of steel protection. The evaluation of the corrosion inhibition of carbon steel (API 5 L-X60) in a solution 1 M of hydrochloric acid was performed using gravimetric method, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The predicted mathematical relationships between the corrosion rate and the inhibitory efficiency in the presence of the butanolic extract of Echium italicum L. (BEEI), when increasing temperature proved a good agreement between experimental and mathematical studies.
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hauhan, Sunny C., Sudhanshu Kumar Jha, Gopal Vijaykumar Lohiya, and Arnima Tamta. "INTRODUCTION OF ANALYTICAL TECHNIQUES USED IN HERBAL DRUG TECHNOLOGY." In Futuristic Trends in Herbal Medicines and Food Products, 136–51. Iterative International Publishers, Selfypage Developers Pvt Ltd, 2024. http://dx.doi.org/10.58532/nbennurch248.
Анотація:
By-products from plants are a great source of bio-active substances, such phenolic acid, carotenoids, and flavonoids (as phenolic compounds), peptide isolate, amino acids (bioactive proteins), fibres and fatty acids, and so on. Bio-active substances are defined as having a biological activity that causes metabolic changes linked to improvements in specific physiological processes or a decreased risk of developing various diseases. Plant sources typically have significant concentrations of bio-active chemicals, including a variety of molecules with various chemical and biological properties. Cancer, cataracts, Senile dementia, Parkinson disease, age-related ailments, and cardiovascular diseases are all at a lesser risk thanks to the bio-active components. Bio-active molecules include vitamins, minerals and other nonnutritious substances known as phytoconstituents, including glucosinolates, phytosterols, carotenoids, terpenoids, phenolic compounds, and folic acid, between others. In contrast to synthetic medications, medicines made from plants frequently have greater than one active ingredient, and the active ingredient or ingredients are frequently unknown. It can take a long time and be expensive to separate one or more chemicals from a raw extract or extract fractions. Many procedure that frequently calls for expertise, many separation processes, and various chromatographic techniques. Using information from several spectroscopic methods, it is possible to determine the structure of certain molecules including IR, mass spectroscopy, nuclear magnetic resonance (NMR), and UV-visible are used
7
Ayembilla, Jacob Apibilla, Phyllis Naa Yarley Otu, Eunice A. Dotse, Abigail Aning, Emmanuel Kweku Ofori, Regina Appiah-Opong, and Henry Asare-Annane. "Antioxidant and Anticancer Potential of Natural Cocoa Extract." In Technological Innovation Driving Sustainable Entrepreneurial Growth in Developing Nations, 156–75. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-9843-9.ch007.
Анотація:
The aim of this study was to investigate antioxidant and anticancer potentials of natural cocoa extracts. Antioxidant properties of the extracts were evaluated by DPPH assay, total phenolic content by Folin-Ciocalteau and reduced glutathione content by O-phthalaldehyde assays. Antiproliferative activity was also evaluated on leukaemia and prostate cancer cell lines using MTT assay. The hydroethanolic extracts of cocoa roots and beans and aqueous cocoa leaves showed high total antioxidant activities with the root extract having the strongest scavenging effect on DPPH and the highest total phenolics content. The hydroethanolic cocoa bean crude extract showed the highest anticancer activity against LNCaP cells, whiles the ethyl acetate fraction of hydroethanolic cocoa leaf exhibited the highest anticancer against PC3. Jurkat and PC3 cells had similar susceptibilities to the natural cocoa extracts. Thus, cocoa has antioxidant and anticancer activity, and the specific bioactive compounds responsible for these activities need to be elucidated in future research.
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Friend, John. "Lignin and Associated Phenolic Acids in Cell Walls." In Molecular Plant Pathology, 9–14. Oxford University PressOxford, 1992. http://dx.doi.org/10.1093/oso/9780199633524.003.0002.
Анотація:
Abstract Many types of phenolic compounds are found in cell wall preparations or as insoluble residues remaining after the extraction of metabolites soluble in organic solvents. This chapter describes procedures for the isolation and analysis of lignin and other phenolic compounds from plant material. Since most analytical methods for phenolic compounds are specific for phenolic hydroxy-groups, it is essential that all soluble phenolic compounds are extracted from the tissue during the preparation of the insoluble residue or cell wall fraction. Many simple phenolic compounds may not be completely extracted by nonaqueous organic solvents. Indeed, the removal of water by acetone or methanol may cause hydrogen-bonding of phenolic compounds, such as chlorogenic acid, to the insoluble residue leading to spurious results. Moreover, it is possible for phenolic compounds to be oxidized by endogenous phenolases, during the extraction procedure. The oxidation products of compounds, such as chlorogenic acid, can then chemically react with freeNH2 or -SH groups on amino acid side chains to yield complex oxidation products bound to protein. This may be cell wall protein itself, or protein which is hydrogen bonded to the cell wall during the extraction procedure.
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Veronique, Traynard, Yuen Muk Wing, and Drapeau Christian. "Seabuckthorn Polyphenols: Characterization, Bioactivities and Associated Health Benefits." In Phenolic Compounds [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.98706.
Анотація:
Sea Buckthorn (Hippophae rhamnoides) has a long history of use as food and medicine in Tibet and Northern Asia, where the plant has been associated with a wide range of health benefits. Sea buckthorn (SB) berry, seed and leaf have been reported to contain more than 190 bioactive compounds, including polyphenols (epicatechin, epigallocatechin, gallic acid, proanthocyanidins, chloregenic acid) and flavonoids (quercetin, isorhamnetin, kampferol glycosides, lutoelin, myricetin). SB represents a good source of phenolic compounds and flavonoids acting in synergy with PUFA such as omegas 3, 6, 7 and 9, vitamins (vitamin C), and organic acids. SB exerts antioxidant, anti-inflammatory, cytoprotective, anti-cancer, hepatoprotective properties, associated with improvement in various metabolic markers such as glycemic control and lipid profile. SB polyphenol fraction also demonstrated significant cardioprotective, antihypertensive and neuroprotective actions. SB acts as a natural stem cell mobilizer associated with significant regenerative properties. As a consequence, SB polyphenol consumption stimulates pancreatic regeneration in animal model of insulin-dependent diabetes. In conclusion, SB polyphenols exert a wide range of health benefits in metabolic health including obesity, diabetes and hypertension, as well as liver, kidney and brain health, positioning sea buckthorn berry extract as an interesting and valuable dietary supplement for natural complementary therapy and for antiaging.
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Rafii, Esfandiar, Jean Claude Maire*, Martin Ngassoum, Robert Faure,, and Louis Lena. "Application of organotin groups as markers in analysis of coal liquefaction products and petroleum fractions." In Chemistry and Technology of Silicon and Tin, 38–52. Oxford University PressOxford, 1992. http://dx.doi.org/10.1093/oso/9780198555803.003.0002.
Анотація:
Abstract Aside from their industrial applications, organotin compounds have also been widely used as intermediates or reagents in organic synthesis. More recently, organotin groups have been used as markers for the structural elucidation of complex molecules with the aid of spectroscopic techniques. The possibility of using tri-n-butyltin compounds as markers is illustrated, with reference to multinuclear NMR spectroscopy, for the quantitative analysis of phenols in liquid fractions derived from coal, and of sulphur compounds in petroleum fractions.
Тези доповідей конференцій з теми "Phenolic fractions":
1
Chang, Jun. "Antioxidant Effect of Phenolic Fractions from Scrophularin ningpoensis Hemsl." In 2012 International Conference on Biomedical Engineering and Biotechnology (iCBEB). IEEE, 2012. http://dx.doi.org/10.1109/icbeb.2012.75.
2
Zhao, Hefei, and Selina Wang. "Isolation and purification phenolic compounds in California olive pomace by pilot-scale C18 gel chromatography." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/hkjz6249.
Анотація:
According to the Food and Agriculture Organization, the United States (mainly in California) produced 151,950 tons of olives in 2019, which resulted in a large amount of pomace waste. While many researchers focused on crude extraction and macroporous resin purification from European olive pomace on an analytical scale, few studies have been conducted to isolate fractions of US olive pomase (OP) by pilot-scale C18 chromatography. Hexane defatted Arbequina California OP was extracted by water, and the extract was loaded to a pilot-scale chromatography column with 262.5 mL C18 gel, and the elute syrup (ES) was collected. Desorptions were applied by 1 L of acidified water (AW), 35% methanol (35M) and 70% methanol (70M), respectively. The fractions were concentrated then freeze-dried. Total phenol contents (TPC) were measured by Folin-Ciocalteu assay. Individual phenols were determined by HPLC-DAD. Results showed that the TPC of the fractions of ES, AW, 35M and 70M were 2.88, 29.39, 170.56 and 235.96 mg gallic acid equivalents/g, respectively. Heatmap cluster analysis showed that ES and AW fractions had similar phenol profiles with hydroxytyrosol and tyrosol-glucoside; and 35M had hydroxytyrosol-glucoside, hydroxytyrosol, tyrosol-glucoside, 4-hydroxyphenylacetic acid (4-HPA), verbascoside and oleuropein; 70M contained hydroxytyrosol, tyrosol-glucoside, tyrosol, but generally had more nonpolar compounds such as verbascoside, rutin and oleuropein. Very interestingly, the 3,4-DHPEA-EDA in water extract at 31.43 min disappeared in 35M and 70M fractions, meanwhile a new peak at 29.25 min showed up which could be a new compound derived from 3,4-DHPEA-EDA possibly because of the acidified process. This study could be the first-ever report of phenol profile of pilot-scale C18 fractions of the US OP. This new data on the chemical compositions of the OP C18 fractions provides practical knowledge for the valorization and industrial food applications of the US olive wastes.
3
Vilkickyte, G., V. Petrikaite, A. Sipailiene, and L. Raudone. "Short Lecture “Ethnopharmacological potential of lingonberry (Vaccinium vitis-idaea L.) phenolic fractions”." In GA – 70th Annual Meeting 2022. Georg Thieme Verlag KG, 2022. http://dx.doi.org/10.1055/s-0042-1758946.
4
Luo, Changsong, and Paul E. DesJardin. "Thermo-Mechanical Damage Modeling for a Glass-Fiber Phenolic-Resin Composite Material." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81719.
Анотація:
The objective of this research is the development of a thermo-mechanical damage model for composite materials subject to high temperature thermal and radiative environments that are representative of large scale fires. The damage to the structure is expressed as two regions of non-charred and charred material. In the char region, the pyrolysis process of resin is complete and there are only fiber, char and gas. Homogenization methods are imposed to treat the damaged material in terms of the volume fractions associated with composite fiber, resin and char. A transport equation for the phase averaged temperature is presented using a Darcy law to account for the gas transport in the structure. Mechanical response in the composite is taken into account by solving a homogenized form of the linear elasticity equations. Required transport properties for temperature and displacement equations are based on mixture weighted properties of the fiber, gas, resin and char and are dependent on the local volume fraction of each. Numerical simulations of a two-dimensional composite clamped beam subject to radiation heat loading are presented. Overall, good agreement is obtained between the numerical predictions and experimental data for temperature and gas pressure with comparisons to the thermal experimental data of Henderson and Florio [8,9]. Results show that during early stages of heating, the decomposition of the resin results in local stress concentrations due to the increase in temperature and pressure.
5
Yücetepe, Aysun, Ayhan Duran, and Beraat Özçelik. "Characterization of Phenolic Compounds in Peel, Pulp andSeed Fractions of Zizyphus Jujube Fruit by UFLC-PDA and Determination of Antioxidant Activity." In 6th International Conference on Innovation in Science and Technology. Acavent, 2019. http://dx.doi.org/10.33422/6th-istconf.2019.07.404.
6
Belashova, O. V., A. V. Zaushintsena, and N. V. Fotina. "BIOTECHNOLOGICAL PROCESS OF CREATING FUNCTIONAL DAIRY PRODUCT ENRICHED WITH THE EXTRACT OF SCUTELLARIA GALERICULATA L." In STATE AND DEVELOPMENT PROSPECTS OF AGRIBUSINESS Volume 2. DSTU-Print, 2020. http://dx.doi.org/10.23947/interagro.2020.2.669-673.
Анотація:
One of the ways to eliminate population diseases and increase the body is resistance to adverse environmental factors is the systematic use of functional food products enriched with a complex of biologically active substances with a wide range of therapeutic effects. The creation of a new, unique functional dairy product was preceded by long-term comparative biochemical studies of Scutellaria baicalensis Georgi and Scutellaria galericulata L. In the grass and roots, biologically active substances of a phenolic nature, such as baicalin, vogonin, scutellarin, etc., were found useful for medicinal purposes. The use of extracts from the of Scutellaria galericulata L. in the development of a functional product based on sour-milk fractions made it possible to obtain curd mass enriched with the biologically active substance of this plant. The functional product meets the organoleptic, physico-chemical, tasting requirements for new functional products and is recommended for introduction into the diet of different population groups by age and functional activity.
7
Bharadwaj, Bharath, Prashant Singh, and Roop L. Mahajan. "Thermal Performance of Different Carbonaceous Nanoparticles as Additives to Thermal Paste as an Interface Material." In ASME 2021 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/ipack2021-69254.
Анотація:
Abstract With increased focus on miniature high power density electronic packages, there is a need for the development of new interface materials with lower thermal resistance. To this end, high conductivity thermal paste or similar thermal interface materials (TIMs), reinforced with superior thermal conductivity materials such as multi-walled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNPs), graphite-derived multilayer graphene (g-MLG) offer an effective strategy to provide efficient paths for heat dissipation from heat source to heat sink. In an earlier paper, we had demonstrated that multilayer graphene derived from coal (coal-MLG) synthesized using our in-house developed one-pot process, has increased presence of phenolic groups on its surfaces, which translates into better dispersion of coal-MLG in silicone thermal paste. In this paper, we first compare the thermal conductance of a high conductivity thermal paste (k = 8.9 W/mK) using coal-MLG as an additive with that realized with other nano additives — MWCNTs, GNPs, and g-MLG. The data shows that coal-MLG as an additive outperforms all the other investigated nano additives in enhancing the thermal performance of the paste. With the coal-MLG as an additive, ∼70% increase in thermal performance was observed as compared to the base thermal paste used. This increase is about 2.5 times higher than that obtained using g-MLG as an additive. We also measured the thermal performance of coal-MLG-based TIM with its different wt.% fractions. The data confirmed our hypothesis that the optimum level of the loading fraction of the additive that can be dispersed in the matrix (paste in this case) before the onset of agglomeration is higher for the coal-MLG (3%) than for the other additives (2%). The implication is further improvement thermal performance with coal-MLG. The data shows the additional thermal enhancement to ∼2X. Finally, since coal-MLG produced by our in-house process is relatively cheaper and more environmentally friendly, we believe that these results would pave the path for enhanced thermal performance with non-silicone thermal pastes at a significantly lower cost. We also expect similar benefits for the silicone-based thermal pastes.
8
Roy, Shrabanti, and Omid Askari. "Chemical Kinetic Study on Reaction Pathway of Anisole Oxidation at Various Operating Condition." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-24233.
Анотація:
Abstract Biofuels are considered as an alternative source of energy which can decrease the growing consumption of fossil fuel, hence decreasing pollution. Anisole (methoxybenzene) is a potential source of biofuel produced from cellulose base compounds. It is mostly available as a surrogate of phenolic rich compound. Because of the attractive properties of this fuel in combustion, it is important to do detail kinetic study on oxidation of anisole. In this study a detail chemical mechanism is developed to capture the chemical kinetics of anisole oxidation. The mechanism is developed using an automatic reaction mechanism generator (RMG). To generate the mechanism, RMG uses some known set of species and initial conditions such as temperature, pressure, and mole fractions. Proper thermodynamic and reaction library is used to capture the aromaticity of anisole. The generated mechanism has 340 species and 2532 reactions. Laminar burning speed (LBS) calculated through constant volume combustion chamber (CVCC) at temperature ranges from 460–550 K, pressure of 2–3 atm and equivalence ratio of 0.8–1.4 is used to validate the generated mechanism. Some deviation with experimental result is observed with the newly generated mechanism. Important reaction responsible for LBS calculation, is selected through sensitivity analysis. Rate coefficient of sensitive reactions are collected from literature to modify and improve the mechanism with experimental result. The generated mechanism is further validated with available ignition delay time (IDT) results ranging from 10–20 atm pressure, 0.5–1 equivalence ratio and 870–1600 K temperature. A good agreement of results is observed at different operating ranges. Oxidation of anisole at stoichiometric condition and atmospheric pressure in jet stirred reactor is also used to compare the species concentration of the mechanism. This newly generated mechanism is considered as a good addition for further study of anisole kinetics.
9
Valli, Enrico, Ilaria Grigoletto, Patricia Garcia Salas, Alessandra Bendini, Federica Pasini, Sebastian Sánchez Villasclaras, Roberto García Ruiz, and Tullia Gallina Toschi. "Study of the Phenolic Fraction for the Valorization of Olive Pomace as a Functional Ingredient." In 2022 AOCS Annual Meeting & Expo. American Oil Chemists' Society (AOCS), 2022. http://dx.doi.org/10.21748/vnbg6136.
Анотація:
Olive oil production is an agro-industrial activity that generates annually about 30 million tons of waste at worldwide level with a potential environmental impact in the Mediterranean area. In olive mill pomace, one of the major by-products, remain large amounts of phenolic compounds, that are widely recognised for their beneficial properties for human health. The aim of this work is to study a possible valorisation strategy for recovering this functional high-added value fraction of olive mill pomace. The herein-tested extraction procedures were applied on two different types of olive by-products, collected from an Italian oil mill. Solid-liquid extraction protocols by using different solvents with low toxicity for the environment and lab operators were tested. In particular, the used solvent mixtures were methanol/water and ethanol/water, in different ratios and volumes. In brief, the mixture composed by the olive mill pomace and the extraction solvents was homogenised, then introduced in an ultrasonic bath to enhance the extraction of the compounds of interest, and finally centrifugated. The supernatant was analysed by HPLC coupled with UV and MS detectors to study the phenolic profile. An aliquot of the obtained polar fraction was hydrolysed to determine the total content of hydroxytyrosol and tyrosol derived, above all, from secoiridoids. The results support that the obtained phenolic extracts, when properly stored, can be used as functional ingredients in the food industry, as well as in other sectors. The project SUSTAINOLIVE “NOVEL APPROACHES TO PROMOTE THE SUSTAINABILITY OF OLIVE GROVES IN THE MEDITERRANEAN” is part of the PRIMA programme supported by the EU under grant agreement No 1811. The information expressed in this abstract reflects the authors’ views; the PRIMA Foundation is not liable for the information contained herein and is not responsible for any use that may be made of the information it contains.
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Tretyakova, A. M., and N. A. Vakhnina. "Application of the phenol-sulfuric acid method for the determination of glycogen in skeletal muscles and liver of rats." In VIII Vserossijskaja konferencija s mezhdunarodnym uchastiem «Mediko-fiziologicheskie problemy jekologii cheloveka». Publishing center of Ulyanovsk State University, 2021. http://dx.doi.org/10.34014/mpphe.2021-189-191.
Анотація:
The possibility of using the phenol-sulfuric acid method for the determination of total glycogen, its acid-soluble and acid-insoluble fractions in the liver and skeletal muscles of rats was studied. It was found that the use of a precipitant in the isolation of total glycogen and its fractions increases the yield of the investigated substances.
Key words: phenol-sulfate method, rats, liver, muscles, total glycogen, acid-soluble glycogen, acid-insoluble glycogen.
Звіти організацій з теми "Phenolic fractions":
1
Delmer, Deborah, Nicholas Carpita, and Abraham Marcus. Induced Plant Cell Wall Modifications: Use of Plant Cells with Altered Walls to Study Wall Structure, Growth and Potential for Genetic Modification. United States Department of Agriculture, May 1995. http://dx.doi.org/10.32747/1995.7613021.bard.
Анотація:
Our previous work indicated that suspension-cultured plant cells show remarkable flexibility in altering cell wall structure in response either to growth on saline medium or in the presence of the cellulose synthesis inhibitor 2,-6-dichlorobenzonitrile (DCB). We have continued to analyze the structure of these modified cell walls to understand how the changes modify wall strength, porosity, and ability to expand. The major load-bearing network in the walls of DCB-adapted dicot cells that lack a substantial cellulose-xyloglucan network is comprised of Ca2+-bridged pectates; these cells also have an unusual and abundant soluble pectic fraction. By contrast, DCB-adapted barley, a graminaceous monocot achieves extra wall strength by enhanced cross-linking of its non-cellulosic polysaccharide network via phenolic residues. Our results have also shed new light on normal wall stucture: 1) the cellulose-xyloglucan network may be independent of other wall networks in dicot primary walls and accounts for about 70% of the total wall strength; 2) the pectic network in dicot walls is the primary determinant of wall porosity; 3) both wall strength and porosity in graminaceous monocot primary walls is greatly influenced by the degree of phenolic cross-linking between non-cellulosic polysaccharides; and 4) the fact that the monocot cells do not secrete excess glucuronoarabinoxylan and mixed-linked glucan in response to growth on DCB, suggests that these two non-cellulosic polymers do not normally interact with cellulose in a manner similar to xyloglucan. We also attempted to understand the factors which limit cell expansion during growth of cells in saline medium. Analyses of hydrolytic enzyme activities suggest that xyloglucan metabolism is not repressed during growth on NaCl. Unlike non-adapted cells, salt-adapted cells were found to lack pectin methyl esterase, but it is not clear how this difference could relate to alterations in wall expansibility. Salt-adaped cell walls contain reduced hyp and secrete two unique PRPP-related proteins suggesting that high NaCl inhibits the cross-linking of these proteins into the walls, a finding that might relate to their altered expansibility.