983 resultados para Total phenolic compounds


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Seaweeds are a major source of biologically active compounds . In the extracellular matrix of these organisms are sulfated polysaccharides that functions as structural components preventing it against dehydration. The fraction 0.9 (FucB) rich in sulfated fucans obtained from brown seaweed Dictyota menstrualis was chemical characterized and evaluated for pharmacological activity by testing anticoagulant activity, stimulatory action on the synthesis of an antithrombotic heparan sulfate, antioxidant activity and its effects in cell proliferation. The main components were FucB carbohydrates (49.80 ± 0.10 %) and sulfate (42.30 ± 0.015 %), with phenolic compounds ( 3.86 ± 0.016 %) and low protein contamination ( 0.58 ± 0.001 % ) . FucB showed polydisperse profile and analysis of signals in the infrared at 1262, 1074 and 930 cm -1 and 840 assigned to S = O bonds sulfate esters , CO bond presence of 3,6- anhydrogalactose , β -D- galactose non- sulfated sulfate and the axial position of fucose C4 , respectively. FucB exhibited moderate anticoagulant activity , the polysaccharides prolonged time (aPTT ) 200 ug ( > 90s ) partial thromboplastin FucB no effect on prothrombin time (PT), which corresponds to the extrinsic pathway of coagulation was observed. This stimulation promoted fraction of about 3.6 times the synthesis of heparan sulfate (HS) by endothelial cells of the rabbit aorta ( RAEC ) in culture compared with cells not treated with FucB . This has also been shown to compete for the binding site with heparin. The rich fraction sulfated fucans exhibited strong antioxidant activity assays on total antioxidant (109.7 and 89.5 % compared with BHT and ascorbic acid standards ) , reducing power ( 71 % compared to ascorbic acid ) and ferric chelation ( 71 , comparing with 5 % ascorbic acid). The fraction of algae showed cytostatic activity on the RAEC cells revealed that the increase of the synthesis of heparan sulfate is not related to proliferation. FucB showed antiproliferative action on cell lines modified as Hela and Hep G2 by MTT assay . These results suggest that FucB Dictyota menstrualis have anticoagulant , antithrombotic , antioxidant potential as well as a possible antitumor action, promoting the stimulation of the synthesis of antithrombotic HS by endothelial cells and is useful in the prevention of thrombosis, also due to its inhibitory action on species reactive oxygen ( ROS ) in some in vitro systems , being involved in promoting a hypercoagulable state

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Salvia species are used worldwide for medicine purposes. In general, these medicinal plants have high amounts of flavonoids and phenolic acids, that are thought to be closely related to their health properties [1,2]. In this work, the aerial parts of Salvia farinacea, Salvia mexico, Salvia greggii and Salvia officinalis were extracted with hot water [3]. Extracts were evaluated for their total phenolic content by an adaptation of the Folin-Ciocalteu method and further analysed by high performance liquid chromatography associated with electrospray mass spectrometry (HPLC-DAD-ESI-MSn) in the negative ion mode [4], in order to identify their individual phenolic constituents. The aqueous extracts of S. farinacea, S. mexico, S. officinalis and S. greggii contained, respectively, 106±13, 159±38, 175±46 and 136±1 μg GAE/mg of total phenolics. These four species were characterized by a clear prevalence of caffeic acid derivatives, in particular of rosmarinic acid (MW 360), that is generally the most abundant phenolic compound in Salvia species [2,3]. In addition, S. mexico and S. officinalis contained moderate amounts of salvianolic acid B (MW 718). Among these two, S. mexico was richer in O-caffeoylquinic acid (MW 354), while the latter presented high amounts of salvianolic acid K (MW 556) and moderate amounts of its structural isomer. All the extracts were enriched in flavones: S. farinacea and S. officinalis contained high amounts of luteolin-O-glucuronide while S. mexico contained luteolin-C-glucoside with respective characteristic mass spectrometry fragmentation pattern m/z at 461→285 and m/z at 447→357, 327. Similarly, S. greggii extract presented high content of luteolin-7-O-glucoside ([M-H]− at m/z 447→ 285) and luteolin-C-glucoside and moderate quantities of apigenin-C-hexoside ([M-H]− at m/z 431→341, 311). Further studies are being undertaken in order to understand the contribution of these phenolic constituents in the biological activities of Salvia plants.

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Salvia species are used worldwide for medicine purposes. In general, these medicinal plants have high amounts of flavonoids and phenolic acids, that are thought to be closely related to their health properties [1,2]. In this work, the aerial parts of Salvia farinacea, Salvia mexico, Salvia greggii and Salvia officinalis were extracted with hot water [3]. Extracts were evaluated for their total phenolic content by an adaptation of the Folin-Ciocalteu method and further analysed by high performance liquid chromatography associated with electrospray mass spectrometry (HPLC-DAD-ESI-MSn) in the negative ion mode [4], in order to identify their individual phenolic constituents. The aqueous extracts of S. farinacea, S. mexico, S. officinalis and S. greggii contained, respectively, 106±13, 159±38, 175±46 and 136±1 μg GAE/mg of total phenolics. These four species were characterized by a clear prevalence of caffeic acid derivatives, in particular of rosmarinic acid (MW 360), that is generally the most abundant phenolic compound in Salvia species [2,3]. In addition, S. mexico and S. officinalis contained moderate amounts of salvianolic acid B (MW 718). Among these two, S. mexico was richer in O-caffeoylquinic acid (MW 354), while the latter presented high amounts of salvianolic acid K (MW 556) and moderate amounts of its structural isomer. All the extracts were enriched in flavones: S. farinacea and S. officinalis contained high amounts of luteolin-O-glucuronide while S. mexico contained luteolin-C-glucoside with respective characteristic mass spectrometry fragmentation pattern m/z at 461→285 and m/z at 447→357, 327. Similarly, S. greggii extract presented high content of luteolin-7-O-glucoside ([M-H]− at m/z 447→ 285) and luteolin-C-glucoside and moderate quantities of apigenin-C-hexoside ([M-H]− at m/z 431→341, 311). Further studies are being undertaken in order to understand the contribution of these phenolic constituents in the biological activities of Salvia plants.

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The present study aimed to characterize the extracts prepared from Pimpinella anisum L. (anise) and Coriandrum sativum L. (coriander) (Apiaceae plants) seeds in terms of phenolic composition, and to correlate the obtained profiles with the antioxidant activity. Anise gave the highest abundance in phenolic compounds (42.09± 0.11 mg/g extract), mainly flavonoids (28.08±0.17 mg/g extract) and phenolic acids (14.01±0.06 mg/g extract), and also the highest antioxidant potential, measured by the ability to inhibit lipid peroxidation and β-carotene bleaching, the reducing power and the free radical scavenging activity. Apigenin and luteolin derivatives, as also caffeoylquinic acid derivatives seem to be directly related with the higher in vitro antioxidant potential of the anise extract. In contrast, the lower antioxidant potential of coriander seems to be due to its lower abundance in phenolic compounds (2.24±0.01 mg/g extract). Further studies are necessary to evaluate the in vivo antioxidant potential of the tested extracts, but the in vitro experiments already performed highlight them as potential health promoters.

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Wild mushrooms are mainly collected during the rainy season and valued as a nutritious food and sources of natural medicines and nutraceuticals. The aim of this study was to determine the chemical composition and bioactive properties (antioxidant, antimicrobial and cytotoxicity) of Polyporus squamosus from two different origins, Portugal and Serbia. The sample from Portugal showed higher contents of as protein (17.14 g/100 g), fat (2.69 g/100 g), ash (3.15 g/100 g) and carbohydrates (77.02 g/100 g); the same sample gave the highest antioxidant activity: highest reducing power, DPPH radical scavenging activity, and lipid peroxidation inhibition in both β-carotene/linoleate and TBARS assay. These results could be related to its higher content in total tocopherols (1968.65 μg/100 g) and phenolic compounds (1.29 mg/100 g). Both extracts exhibited antibacterial activity against all the tested organisms. The samples from Serbia gave higher overall antibacterial activity and showed excellent antibiofilm activity (88.30 %). Overall, P. squamosus methanolic extracts possessed antioxidant, antimicrobial, antibiofilm and anti-quorum sensing activity, and without toxicity for liver cells. This investigation highlights alternatives to be explored for the treatment of bacterial infections, in particular against Pseudomonas aeruginosa. This study provides important results for the chemical and bioactive properties, especially antimicrobial activity of the mushroom P. squamosus. Moreover, to the authors’ knowledge this is the first report on sugars, organic acids, and individual phenolic compounds in P. squamosus.

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The production of natural extracts requires suitable processing conditions to maximize the preservation of the bioactive ingredients. Herein, a microwave-assisted extraction (MAE) process was optimized, by means of response surface methodology (RSM), to maximize the recovery of phenolic acids and flavonoids and obtain antioxidant ingredients from tomato. A 5-level full factorial Box-Behnken design was successfully implemented for MAE optimization, in which the processing time (t), temperature (T), ethanol concentration (Et) and solid/liquid ratio (S/L) were relevant independent variables. The proposed model was validated based on the high values of the adjusted coefficient of determination and on the non-significant differences between experimental and predicted values. The global optimum processing conditions (t=20 min; T=180 ºC; Et=0 %; and S/L=45 g/L) provided tomato extracts with high potential as nutraceuticals or as active ingredients in the design of functional foods. Additionally, the round tomato variety was highlighted as a source of added-value phenolic acids and flavonoids.

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Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia - UL

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Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

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The aim of this study was to evaluate the anti-inflammatory activity of Petit Verdot Extract and hexane, chloroform and ethyl acetate fractions obtained from grape pomace, in addition to identifying active compounds. The PVE and EAF reduced significantly paw edema and neutrophil migration when compared with control groups. The PVE reduced levels of TNF-α and IL1-β in the peritoneal fluid, whereas the EAF did not reduce cytokines significantly. Two hydroxybenzoic acids, two proanthocyanidins, three flavan-3-ol monomers and three anthocyanins were identified in the PVE and EAF by LC-MS/MS. The stilbene transresveratrol was identified only in the EAF. The phenolic compounds were quantified using HPLC-DAD analysis, except for the stilbenes, which were not sensible for the detection by the method. Since PVE and EAF showed significantly anti-inflammatory effects and high concentration of phenolic compounds, we concluded that Petit Verdot pomace could be an interesting source of anti-inflammatory bioactives.

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Purpose: To evaluate the potential of active compounds derived from moss in the prevention and treatment of various diseases. Methods: Three species of moss were extracted with deionized water at 95 °C, and with 70.5 % ethanol at 85 °C. Analysis of total phenolic contents (TPC) of the extracts were performed by FolinCiocalteu (FC) method. The antioxidant activity of the extracts were determined using three methods, namely, by 2,2\'-azino-bis(3-ethylbenzothiazoline-6-sulphonic) acid (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). In vivo effects were evaluated in mice fed high fat diet (HFD) supplemented with 20 % ground moss. Cholesterol levels in HFD were evaluated by ophthalaldehyde method. Serum triglyceride levels were measured using triglyceride (TG) kit, while blood insulin level and leptin concentration were measured by enzyme-linked immunosorbent assay (ELISA) kit. Results: The moss extracts exhibited antioxidative effects, as evidenced of . TPC of 47.20 ± 11.20 to 119.87 ± 11.51 mg GAE/mg, respectively. ABTS scavenging activity was 1078.11 ± 18.95 to 2587.33 ± 46.19 μmol Trolox/mg, DPPH scavenging activity of were 42.11 ± 8.22 to 298.78 ± 20.02 μmol Trolox/mg, and FRAP value of 393.19 ± 24.64 to 1070.14 ± 17.92 μmol Trolox/mg, respectively. Mice fed with 20 % ground moss did not show any significant effect (p < 0.05) on visceral weight and blood lipid levels of HFD, while leptin concentrations reduced significantly to 4.74 ± 0.00 and 0.20 ± 0.00 ng/dL) relative to HFD alone (26.72 ± 6.53 ng/dL). Conclusion: Moss can potentially be used as an antioxidative ingredient, for the improvement of overall human health, suggesting that important medical benefits associated with moss consumption. However, further investigations are required to ascertain this.

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Kiwi fruit is a highly nutritional fruit due to the high level of vitamin C and its strong antioxidant capacity due to a wide number of phytonutrients including carotenoids, lutein, phenolics, flavonoids and chlorophyll [1]. Drying consists of a complex process in which simultaneous heat and mass transfer occur. Several alterations occur during the drying of foods at many levels (physical, chemical, nutritional or sensorial) which are influenced by a number of factors, including processing conditions [2]. Temperature is particularly important because of the effects it produces at the chemical and also at the physical level, particularly colour and texture [3]. In the present work were evaluated the changes in sliced kiwi when exposed to air drying at different temperatures (50, 60, 70, 80 ºC), namely in terms of some chemical properties like ascorbic acid or phenolic compounds, physical characteristics like colour and texture and also at the sensorial level. All experiments followed standard established procedures and several replicates were done to assess each property. The results obtained indicated that moisture was reduced with drying by 74 to 87%, depending on the temperature. Also ascorbic acid decreased with drying, being 7% for 50 ºC and increasing up to 28% for the highest temperature (80 ºC). The phenolic compounds and antioxidant activity were also very much affected by the drying temperature. The water activity of the dried samples varied from 0.658 to 0.753, being compatible with a good preservation. Regarding colour, the total colour difference between the dried samples and the fresh sample was found to vary in the range 9.45 – 17.17. The textural parameters were also much affected by drying, namely hardness which decreased by 45 to 72 %, and all other parameters increased: cohesiveness (approximately doubled), springiness (increased 2 to 3 times) and chewiness which increased up to 2.5 times that off the fresh sample. Adhesiveness, which was observed for the fresh samples (-4.02 N.s) disappeared in all the dried samples. The sensorial analysis made to the dried samples allowed establishing the sensorial profiles as shown in Figure 1.

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Currently, society faces a number of challenges related to the large amounts of organic wastes generated and accumulated by the increasing expansion of agroindustrial activities1. Most of these wastes are rich in lignocellulosic compounds, which represents a major fraction of all plant biomass (of above 90%), so, its degradation is crucial for global carbon cycle2. These organic wastes may be introduced directly on agriculture sector as soil organic amendment, however, these might contain phytochemicals, such as phenolic compounds which may introduce toxic effects to soil and to beneficial organisms. Transformation and degradation of these renewable organic wastes into composts (COMPOSTING) is a possible solution for these problems and an environmentally friendly processes that allows make use of natural resources efficiently3. The main potential handicap is generation and emission of greenhouse gases such as carbon dioxide (CO2 ), methane (CH4 ) and nitrous oxide (N2O) and another ones which may led serious problems like nitric oxide (NO) and ammonia (NH3) 4. For this reason, quantification of GHG emissions from composting and finding possible relations with the chemical and structural composition of the wastes used is crucial to the development of technologies for mitigating emissions and should help to make decisions concerning waste management.

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Bananas arise as one of the most popular fruits consumed all around the world. Banana belongs to the genus Musa from the family Musaceae. It is original from tropical regions and presents a strong ability to protect itself from the oxidative stress caused by extreme climatic conditions such as intense sunshine and high temperature. For this protection, bananas increase the production of bioactive compounds with antioxidant activity, which protect the fruit from the oxidative damage. Scientific studies have demonstrated that bananas (both in the pulp and peel) contain different antioxidant compounds, like vitamins (A, B, C and E), β-carotene and phenolic compounds (catechin, epicatechin, lignin, tannins, anthocyanins). Furthermore, banana is also notably rich in minerals, like potassium and phosphorus. The knowledge about the chemical composition and the contents in compounds with biological activity is of high interest given the importance of bananas as a valuable food all over the world. However, because bananas are perishable due to some factors like chemical reactions, including those that result in the production of ethylene, their postharvest conservation in pivotal for the commercialization. The effects of postharvest treatments and storage conditions on the composition of bananas are, therefore, essential. In this way, the present chapter focus on the composition of bananas, including macronutrients, micronutrients and bioactive compounds, as well as the effect of postharvest treatments and storage conditions in the quality of bananas.

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The aim of present work was to investigate the phenolic and volatile composition of cherry, acacia, and oak (from different species) wood chips. By the use of HPLC-DAD 18 different phenolic compounds were detected and quantified while for volatile composition, 33 different compounds were detected by GC-MS. In general, wood samples from oak species showed the higher number of phenolic compounds detected, while cherry wood samples showed the lowest levels. In addition, some individual phenolic compounds were detected, specifically in some wood samples, such as robinetin in acacia woods and naringenin in cherry wood. For volatile composition, cherry wood chips samples showed the lowest volatile composition followed by increasing order by acacia, French, Portuguese and American wood chip samples. Oak wood chip samples from American species showed the highest volatile content, as a result of high levels of several specific compounds (furfural, 5-methyfurfural, β-methyl-γ-octalactones, guaiacol, vanillin and siringaldehyde).

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Mature berries of Pinot Noir grapevines were sampled across a latitudinal gradient in Europe, from southern Spain to central Germany. Our aim was to study the influence of latitude-dependent environmental factors on the metabolite composition (mainly phenolic compounds) of berry skins. Solar radiation variables were positively correlated with flavonols and flavanonols and, to a lesser extent, with stilbenes and cinnamic acids. The daily means of global and erythematic UV solar radiation over long periods (bud break-veraison, bud break-harvest, and veraison-harvest), and the doses and daily means in shorter development periods (5–10 days before veraison and harvest) were the variables best correlated with the phenolic profile. The ratio between trihydroxylated and monohydroxylated flavonols, which was positively correlated with antioxidant capacity, was the berry skin variable best correlated with those radiation variables. Total flavanols and total anthocyanins did not show any correlation with radiation variables. Air temperature, degree days, rainfall, and aridity indices showed fewer correlations with metabolite contents than radiation. Moreover, the latter correlations were restricted to the period veraison-harvest, where radiation, temperature, and water availability variables were correlated, making it difficult to separate the possible individual effects of each type of variable. The data show that managing environmental factors, in particular global and UV radiation, through cultural practices during specific development periods, can be useful to promote the synthesis of valuable nutraceuticals and metabolites that influence wine quality.