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Phenolic Acids (phenolic + acid)
Kinds of Phenolic Acids Terms modified by Phenolic Acids Selected AbstractsNovel Conjugates of Aspirin with Phenolic Acid as Anti-inflammatory Agents Having Significantly Reduced Gastrointestinal ToxicityARCHIV DER PHARMAZIE, Issue 4 2010Shan Jiang Abstract A series of novel conjugates of aspirin with natural phenolic acid antioxidants connected through a diol linker were designed and synthesized as potential bifunctional agents combining antioxidant and anti-inflammatory activity for reducing gastrointestinal toxicity. In general, the conjugates were found to be efficient antioxidants and many of them demonstrated much more potent anti-inflammatory activity than aspirin. Among them, 5a and 5b which bear the best anti-inflammatory activity exhibited significantly reduced ulcerogenic potency and toxicity compared to aspirin. However, it is evident that the anti-inflammatory activity of these dual-acting molecules in vivo, was not simply consistent with their antioxidant ability in vitro. [source] Extraction, Identification, and Quantification of Flavonoids and Phenolic Acids in Electron Beam-Irradiated Almond Skin PowderJOURNAL OF FOOD SCIENCE, Issue 3 2009A.S. Teets ABSTRACT:, The effect of electron beam irradiation doses from 0 to 30 kGy on extraction yield and phenolic compounds was evaluated in almond skin phenolic extracts (ASPE). Total soluble phenols and distribution of phenolic compounds from acidified methanol ASPE and 52% methanol ASPE were quantified using Folin,Ciocalteau method, liquid chromatography with diode array and fluorescence detection, and negative ion electrospray-mass spectrometry. Electron beam irradiation increased extraction yield by as much as 23%, with the greatest increase observed in the acidified methanol ASPE. Irradiated samples extracted with acidified methanol also exhibited an increase in extractable phenols (Folin,Ciocalteau) and total HPLC-resolved phenolics at all irradiation doses. Samples extracted with 52% methanol exhibited an increase at 10 and 20 kGy, but a 31% decrease at 30 kGy. An increase in aglycones respective to their glycosides was not observed with irradiation. Therefore, the increase in phenolics was attributed to release of phenolics from their cellular matrix. [source] Methodology Optimization for Quantification of Total Phenolics and Individual Phenolic Acids in Sweetpotato (Ipomoea batatas L.) RootsJOURNAL OF FOOD SCIENCE, Issue 7 2007M.S. Padda ABSTRACT:, Phenolic acids are one of the several classes of naturally occurring antioxidant compounds found in sweetpotatoes. Simplified, robust, and rapid methodologies were optimized to quantify total and individual phenolic acids in sweetpotato roots. Total phenolic acid content was quantified spectrophotometrically using both Folin,Denis and Folin,Ciocalteu reagents. The Folin,Ciocalteu reagent gave an overestimation of total phenolic acids due to the absorbance of interfering compounds (that is, reducing sugars and ascorbic acid). Individual phenolic acids were quantified by high-performance liquid chromatography (HPLC) using the latest in column technology. Four reversed-phase C18 analytical columns with different properties (dimensions, particle size, particle shape, pore size, and carbon load) were compared. Three different mobile phases using isocratic conditions were also evaluated. A column (4.6 × 150 mm) packed with 5-,m spherical silica particles of pore size 110 Å combined with 14% carbon load provided the best and fast separation of individual phenolic acids (that is, chlorogenic acid, caffeic acid, and 3 isomers of dicaffeoylquinic acid) with a total analysis time of less than 7 min. Among the 3 mobile phases tested, a mobile phase consisting of 1% (v/v) formic acid aqueous solution: acetonitrile: 2-propanol, pH 2.5 (70:22:8, v/v/v) gave adequate separation. Among the solvents tested, aqueous mixtures (80:20, solvent:water) of methanol and ethanol provided higher phenolic acid extraction efficiency than the aqueous mixture of acetone. [source] Carbonic Anhydrase Inhibitors: Inhibition of Human Erythrocyte Isozymes I and II with a Series of Phenolic AcidsCHEMICAL BIOLOGY & DRUG DESIGN, Issue 5 2010S. Beyza Öztürk Sar, kaya The inhibitory effects of some phenolic acids on the cytosolic human carbonic anhydrase (hCA, EC 4.2.1.1) isozymes hCA I and hCA II were investigated. Ellagic acid, gallic acid, ferulic acid, caffeic acid, quercetin, p -coumaric acid, p -hydroxybenzoic acid, and syringic acid showed KI values in the range of 99,1061 ,m for hCA I and of 105,758 ,m against hCA II, respectively. Quercetin (for hCA I), p -coumaric acid (for hCA II), and gallic acid (for hCA II) exhibited competitive inhibitory effects with 4-nitrophenyl acetate as substrate. All of the other phenolic acids were found as non-competitive inhibitors with 4-nitrophenylacetate as substrate for hCA I and hCA II. The phenolic acids investigated here showed thus interesting hCA I and hCA II inhibitory effects and might be used as leads for generating enzyme inhibitors possibly targeting other CA isoforms which have not been yet assayed for their interactions with such agents. [source] BACE1 (Beta-Secretase) Inhibitory Phenolic Acids and a Novel Sesquiterpenoid from Homalomena occultaCHEMISTRY & BIODIVERSITY, Issue 4 2010Xiao-Yan Tian Abstract Four phenolic acids, namely 2-[(Z)-heptadec-11-enyl]-6-hydroxybenzoic acid (1), 2-[(6Z,9Z,12Z)-heptadeca-6,9,12-trienyl]-6-hydroxybenzoic acid (2), 2-[(9Z,12Z)-heptadeca-9,12-dienyl] - 6 - hydroxybenzoic acid (3), and 2-hydroxy-6-(12-phenyldodecyl)benzoic acid (4), and one sesquiterpene, asperpenoid (5), were isolated from the 95% EtOH extract of the roots of Homalomena occulta, among which 1, 2, and 5 represent new compounds. Further, the phenolic acids 1,4 exhibited BACE1 (, -secretase) inhibitory activity with IC50 values of 6.23±0.94, 6.28±0.63, 7.93±0.38, and 7.65±0.62,,M, respectively. [source] Decomposition of Allelopathic Plants in SoilJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2005T. D. Xuan Abstract Higher plants with strong allelopathic properties are commonly incorporated into soil for weed-control purposes. To understand the phytotoxic variation in the soil, which can be utilized for weed control through the use of allelopathic plants, the decomposition of alfalfa (Medicago sativa L. cv. Rasen) and kava (Piper methysticum L.) after soil amendment were evaluated. Both alfalfa and kava strongly inhibited barnyardgrass and monochoria growth for up to 10 days (80,100 % weed control). After 20,25 days, the magnitude of inhibition was drastically reduced, but was still effective (50 % weed control). A number of phenolic acids were detected in the soil even 50 days after incorporation in low concentration, but their concentrations reached a maximum after 10,15 days and were efficacious until 20,25 days. Phenolic acids varied between alfalfa and kava. The variations in electrical conductivity (EC) and osmotic pressure (OP) were strongly related to chemicals and toxic compounds exuded into the soil during decomposition and were proportional to the magnitude of inhibition observed, whereas pH did not appear to be correlated with inhibition. The decomposition of several unknown inhibitors present in kava was also analysed and assessed. Our findings indicate that these growth inhibitors were almost disintegrated in soil after 10 days, but strong inhibition was detected until 25 days after amendment. Results from this study demonstrate that chemicals released from allelopathic plants incorporated into soil are toxic and cause inhibition of certain species and could be exploited as a biological tool for weed management. [source] Methodology Optimization for Quantification of Total Phenolics and Individual Phenolic Acids in Sweetpotato (Ipomoea batatas L.) RootsJOURNAL OF FOOD SCIENCE, Issue 7 2007M.S. Padda ABSTRACT:, Phenolic acids are one of the several classes of naturally occurring antioxidant compounds found in sweetpotatoes. Simplified, robust, and rapid methodologies were optimized to quantify total and individual phenolic acids in sweetpotato roots. Total phenolic acid content was quantified spectrophotometrically using both Folin,Denis and Folin,Ciocalteu reagents. The Folin,Ciocalteu reagent gave an overestimation of total phenolic acids due to the absorbance of interfering compounds (that is, reducing sugars and ascorbic acid). Individual phenolic acids were quantified by high-performance liquid chromatography (HPLC) using the latest in column technology. Four reversed-phase C18 analytical columns with different properties (dimensions, particle size, particle shape, pore size, and carbon load) were compared. Three different mobile phases using isocratic conditions were also evaluated. A column (4.6 × 150 mm) packed with 5-,m spherical silica particles of pore size 110 Å combined with 14% carbon load provided the best and fast separation of individual phenolic acids (that is, chlorogenic acid, caffeic acid, and 3 isomers of dicaffeoylquinic acid) with a total analysis time of less than 7 min. Among the 3 mobile phases tested, a mobile phase consisting of 1% (v/v) formic acid aqueous solution: acetonitrile: 2-propanol, pH 2.5 (70:22:8, v/v/v) gave adequate separation. Among the solvents tested, aqueous mixtures (80:20, solvent:water) of methanol and ethanol provided higher phenolic acid extraction efficiency than the aqueous mixture of acetone. [source] Phenolic Acid Content and Composition in Leaves and Roots of Common Commercial Sweetpotato (Ipomea batatas L.) Cultivars in the United StatesJOURNAL OF FOOD SCIENCE, Issue 6 2007V.-D. Truong ABSTRACT:, Phenolic acids in commercially important sweet potato cultivars grown in the United States were analyzed using reversed-phase high-performance liquid chromatography (HPLC). Caffeic acid, chlorogenic acid, 4,5-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 3,4-di-O-caffeoylquinic acid were well separated with an isocratic elution in less than 25 min compared to about 120 min for analyzing and re-equilibrating the column with a gradient method. The isocratic elution order of these caffeoylquinic acid derivatives was confirmed by LC-MS/MS. Chlorogenic acid was the highest in root tissues, while 3,5-di-O-caffeoylquinic acid and/or 4,5-di-O-caffeoylquinic acid were predominant in the leaves. Steam cooking resulted in statistically nonsignificant increases in the concentration of total phenolics and all the individual phenolic acids identified. Sweetpotato leaves had the highest phenolic acid content followed by the peel, whole root, and flesh tissues. However, there was no significant difference in the total phenolic content and antioxidant activity between purees made from the whole and peeled sweet potatoes. [source] New developments in the chemistry and biology of the bioactive constituents of tanshen,MEDICINAL RESEARCH REVIEWS, Issue 1 2007Xihong Wang Abstract Tanshen, the rhizome of Salvia miltiorrhiza Bunge, has been used in Chinese traditional medicine (TCM) for multiple therapeutic remedies. The major constituents of Tanshen include water-soluble phenolic acids and lipophilic tanshinones. Phenolic acids possess antioxidant and anticoagulant activities, whereas tanshinones show antibacterial, antioxidant, and antineoplastic activities. This review will focus on recent developments concerning the chemical constituents of Tanshen and their biological activities. These chemical and biological studies continue to increase our understanding about a scientific basis for the traditional clinical use of Tanshen and can also contribute to the development of new drug candidates. Recently, in the author's laboratory, a new compound, neo-tanshinlactone, was discovered to have potent selective antibreast cancer activity. This compound might serve as a lead for developing promising antibreast cancer clinical trials candidates. © 2006 Wiley Periodicals, Inc. Med Res Rev, 27, No. 1, 133,148, 2007 [source] Phenolic acids in black raspberry and in the gastrointestinal tract of pigs following ingestion of black raspberryMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue S1 2009Xianli Wu Abstract Black raspberries (BRB) contain high levels of polyphenols and have been demonstrated to be chemopreventive. In order to investigate the underlying mechanism and study the metabolism of anthocyanins, pigs were fed freeze-dried BRB powder or purified diet (control) and three segments of the gastrointestinal (GI) tract (small intestine, cecum, and colon; 4 h after feeding) were collected for analysis of phenolic acids. Protocatechuic acid was the major phenolic acid (8.35 mg/100 g, dry weight (DW)) in BRB, followed by p -coumaric acid (1.63 mg/100 g, DW), caffeic acid (1.34 mg/100 g, DW), ferulic acid (0.24 mg/100 g, DW), and 3-hydroxybenzoic acid (0.20 mg/100 g, DW). Recoveries of these five phenolic acids in the whole GI tract were 199.9 ± 54.0%, 7.0 ± 3.0%, 37.0 ± 9.7%, 56.6 ± 31.3%, and 916.8 ± 642.3% (mean ± SEM, n = 5), respectively, and quantities in contents of the GI tract ranged from 0.13 ± 0.05 ,mol (p -coumaric acid) to 23.47 ± 6.09 ,mol (protocatechuic acid) (mean ± SEM, n = 5). Six other phenolic acids were detected primarily in the cecum and/or colon which were not in BRB, with total contents in the GI tract ranging from 0.18 ± 0.18 ,mol (homovanillic acid) to 8.49 ± 4.31 ,mol (homoprotocatechuic acid). Total phenolic acids in the GI tract were 49.32 ± 16.37 ,mol (mean ± SEM, n = 5). Phenolic acids measured in the GI tract accounted for only 6.31% of the degraded anthocyanins. [source] Metabolic effects of p -coumaric acid in the perfused rat liverJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2006Leonardo C.N. Lima The p -coumaric acid, a phenolic acid, occurs in several plant species and, consequently, in many foods and beverages of vegetable origin. Its antioxidant activity is well documented, but there is also a single report about an inhibitory action on the monocarboxylate carrier, which operates in the plasma and mitochondrial membranes. The latter observation suggests that p -coumaric acid could be able to inhibit gluconeogenesis and related parameters. The present investigation was planned to test this hypothesis in the isolated and hemoglobin-free perfused rat liver. Transformation of lactate and alanine into glucose (gluconeogenesis) in the liver was inhibited by p -coumaric acid (IC50 values of 92.5 and 75.6 ,M, respectively). Transformation of fructose into glucose was inhibited to a considerably lower degree (maximally 28%). The oxygen uptake increase accompanying gluconeogenesis from lactate was also inhibited. Pyruvate carboxylation in isolated intact mitochondria was inhibited (IC50 = 160.1 ,M); no such effect was observed in freeze,thawing disrupted mitochondria. Glucose 6-phosphatase and fructose 1,6-bisphosphatase were not inhibited. In isolated intact mitochondria, p -coumaric acid inhibited respiration dependent on pyruvate oxidation but was ineffective on respiration driven by succinate and ,-hydroxybutyrate. It can be concluded that inhibition of pyruvate transport into the mitochondria is the most prominent primary effect of p -coumaric acid and also the main cause for gluconeogenesis inhibition. The existence of additional actions of p -coumaric acid, such as enzyme inhibitions and interference with regulatory mechanisms, cannot be excluded. © 2006 Wiley Periodicals, Inc. J Biochem Mol Toxicol 20:18,26, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20114 [source] The Green Oat Story: Possible Mechanisms of Green Color Formation in Oat Products during CookingJOURNAL OF FOOD SCIENCE, Issue 6 2009D.C. Doehlert ABSTRACT:, Consumers occasionally report greenish colors generated in their oat products when cooking in tap water. Here we have investigated pH and ferrous (Fe2+) ion as possible mechanisms for this color change. Steel-cut oat groats can turn brown-green color when cooked in alkaline conditions (pHs 9 to 12). Extraction of this color with methanol, and high-pressure liquid chromatography indicated a direct association of this color with the phenolic acid or avenanthramide content of the oat. The presence of 50 mM NaHCO3 in water will cause oat/water mixtures to turn alkaline when cooked as CO2 is driven off, generating OH, ion. Although tap water rarely, if ever, contains so much bicarbonate, bicarbonate is used as a leavening agent in baking applications. Industrial interests using baking soda or alkaline conditions during oat processing should be aware of possible off color generation. We have also found that as little as 10 ppm Fe2+ will turn oat products gray-green when cooked. The aleurone stained darker than the starchy endosperm. Other divalent cations, such as Ca2+ or Mg2+ had no effect on cooked oat color. As much as 50 ppm Fe2+ may be found in freshly pumped well water, but Fe2+ reacts quickly with oxygen and precipitates as Fe(OH)3. Thus, some freshly pumped well water may turn oats green when cooked, but if the water is left under atmospheric conditions for several hours, no discoloration will appear in the cooked oats. [source] Influence of branch bending on sugar, organic acid and phenolic content in fruits of ,Williams' pears (Pyrus communis L.)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 14 2006Mateja Colaric Abstract Selected sugars, organic acids and phenolic compounds were analysed in mature fruits of ,Williams' pears using high-performance liquid chromatography. Fruits were harvested from the branches of trees tested in three treatments: branches were bent in summer 2003 (1 September), in spring 2004 (15 May) and control (branches were not bent). Pears contained up to 73.54 g kg,1 fresh weight (FW) of fructose, 9.42 g kg,1 FW of glucose, 7.94 g kg,1 FW of sucrose and 24.59 g kg,1 FW of sorbitol. Major organic acids were (in order of descending quantity) citric, malic, shikimic and fumaric acid (up to 3.05 g kg,1 FW, 2.24 g kg,1 FW, 71.79 mg kg,1 FW and 0.49 mg kg,1 FW, respectively). Chlorogenic acid (280.86,357.34 mg kg,1 FW) was the predominant phenolic acid, followed in concentration (mg kg,1 FW) by syringic acid (95.46,131.32), epicatechin (46.55,83.09), catechin (25.67,44.81), vanillic acid (1.87,3.48), sinapic acid (0.83,1.72) and caffeic acid (0.72,1.04). Significant differences in content of fructose, sorbitol, total sugars, catechin, epicatechin, sinapic acid, syringic acid, and a sum of determined phenolic compounds were observed among the treatments. Fruits from summer bending branches had the lowest content of individual sugars, citric acid and phenolic compounds and the highest content of malic, shikimic and fumaric acid. The highest content of fructose, sorbitol, sucrose, total sugars, caffeic acid, catechin, epicatechin and syringic acid were determined in the fruits from the spring treatment. In the control treatment the highest content of glucose, citric acid, chlorogenic acid, sinapic acid, vanillic acid, as well a sum of determined phenolics, were observed. The lowest content of fumaric acid was in the spring treatment and of malic and shikimic acid in the control. Copyright © 2006 Society of Chemical Industry [source] Inhibition of browning by antibrowning agents and phenolic acids or cinnamic acid in the glucose,lysine modelJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2005Eun-Jung Kwak Abstract The effects of antibrowning agents and phenolic acids or cinnamic acid on the inhibition of browning were investigated with a glucose,lysine model. Six antibrowning agents (cysteine, glutathione, sodium sulfite, pentasodium tripolyphosphate, citric acid and oxalic acid) and four phenolic acids (ferulic, hydroxybenzoic, syringic and vanillic acids) were used. In order to investigate the antibrowning capacity of these agents, model solutions containing glucose, lysine and an antibrowning agent were heated at 50 °C in the presence of FeCl2, before being stored in nitrogen or air at 4 °C or 30 °C. Browning was accelerated to some degree during storage in air at 30 °C. In the case of storage at 4 °C, however, no browning was detected in nitrogen after four weeks. Citric acid was the most efficient antibrowning agent during storage in air at 30 °C and inhibited browning to 36% after four weeks. However, its antibrowning capacity was increased by 8,15% in the presence of any of the phenolic acids or cinnamic acid, essentially independently of concentration in the range 10 µM to 10 mM or the type of phenolic acid. Copyright © 2005 Society of Chemical Industry [source] Ferulic acid: pharmaceutical functions, preparation and applications in foodsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2004Shiyi Ou Abstract Ferulic acid (4-hydroxy-3-methoxycinnamic acid), an effective component of Chinese medicine herbs such as Angelica sinensis, Cimicifuga heracleifolia and Lignsticum chuangxiong, is a ubiquitous phenolic acid in the plant kingdom. It is mainly conjugated with mono- and oligosaccharides, polyamines, lipids and polysaccharides and seldom occurs in a free state in plants. Ferulic acid is a phenolic acid of low toxicity; it can be absorbed and easily metabolized in the human body. Ferulic acid has been reported to have many physiological functions, including antioxidant, antimicrobial, anti-inflammatory, anti-thrombosis, and anti-cancer activities. It also protects against coronary disease, lowers cholesterol and increases sperm viability. Because of these properties and its low toxicity, ferulic acid is now widely used in the food and cosmetic industries. It is used as the raw material for the production of vanillin and preservatives, as a cross-linking agent for the preparation of food gels and edible films, and as an ingredient in sports foods and skin protection agents. Ferulic acid can be prepared by chemical synthesis and through biological transformation. As polysaccharide ferulate is a natural and abundant source of ferulic acid, preparation of ferulic acid from plant cell wall materials will be a prospective pathway. Copyright © 2004 Society of Chemical Industry [source] Phenolic acids in black raspberry and in the gastrointestinal tract of pigs following ingestion of black raspberryMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue S1 2009Xianli Wu Abstract Black raspberries (BRB) contain high levels of polyphenols and have been demonstrated to be chemopreventive. In order to investigate the underlying mechanism and study the metabolism of anthocyanins, pigs were fed freeze-dried BRB powder or purified diet (control) and three segments of the gastrointestinal (GI) tract (small intestine, cecum, and colon; 4 h after feeding) were collected for analysis of phenolic acids. Protocatechuic acid was the major phenolic acid (8.35 mg/100 g, dry weight (DW)) in BRB, followed by p -coumaric acid (1.63 mg/100 g, DW), caffeic acid (1.34 mg/100 g, DW), ferulic acid (0.24 mg/100 g, DW), and 3-hydroxybenzoic acid (0.20 mg/100 g, DW). Recoveries of these five phenolic acids in the whole GI tract were 199.9 ± 54.0%, 7.0 ± 3.0%, 37.0 ± 9.7%, 56.6 ± 31.3%, and 916.8 ± 642.3% (mean ± SEM, n = 5), respectively, and quantities in contents of the GI tract ranged from 0.13 ± 0.05 ,mol (p -coumaric acid) to 23.47 ± 6.09 ,mol (protocatechuic acid) (mean ± SEM, n = 5). Six other phenolic acids were detected primarily in the cecum and/or colon which were not in BRB, with total contents in the GI tract ranging from 0.18 ± 0.18 ,mol (homovanillic acid) to 8.49 ± 4.31 ,mol (homoprotocatechuic acid). Total phenolic acids in the GI tract were 49.32 ± 16.37 ,mol (mean ± SEM, n = 5). Phenolic acids measured in the GI tract accounted for only 6.31% of the degraded anthocyanins. [source] Multi-walled carbon nanotube composites with polyacrylate prepared for open-tubular capillary electrochromatographyELECTROPHORESIS, Issue 19 2010Jian-Lian Chen Abstract A new phase containing immobilized carbon nanotubes (CNTs) was synthesized by in situ polymerization of acid-treated multi-walled CNTs using butylmethacrylate (BMA) as the monomer and ethylene dimethacrylate as the crosslinker on a silanized capillary, forming a porous-layered open-tubular column for CEC. Incorporation of CNT nanomaterials into a polymer matrix could increase the phase ratio and take advantage of the easy preparation of an OT-CEC column. The completed BMA-CNT column was characterized by SEM, ATR-IR, and EOF measurements, varying the pH and the added volume organic modifier. In the multi-walled CNTs structure, carboxylate groups were the major ionizable ligands on the phase surface exerting the EOF having electroosmotic mobility, 4.0×104,cm2,V,1,S,1, in the phosphate buffer at pH 2.8 and RSD values (n=5), 3.2, 4.1, and 4.3%, for three replicate capillaries at pH 7.6. Application of the BMA-CNT column in CEC separations of various samples, including nucleobases, nucleosides, flavonoids, and phenolic acids, proved satisfactory upon optimization of the running buffers. Their optima were found in the borate buffers at pH 9.0/50,mM, pH 9.5/10,mM/50% v/v ACN, and pH 9.5/30,mM/10% v/v methanol, respectively. The separations could also be used to assess the relative contributions of electrophoresis and chromatography to the CEC mechanism by calculating the corresponding velocity and retention factors. Discussions about interactions between the probe solutes and the bonded phase included the ,,, interactions, electrostatic repulsion, and hydrogen bonding. Furthermore, a reversed-phase mode was discovered to be involved in the chromatographic retention. [source] Separation of phenolic acids by capillary electrophoresis with indirect contactless conductometric detectionELECTROPHORESIS, Issue 7 2006Petr Kubá Abstract A new method for the electrophoretic separation of nine phenolic acids (derivatives of benzoic and cinnamic acids) with contactless conductometric detection is presented. Based on theoretical calculations, in which the mobility of the electrolyte co- and counterions and mobility of analytes are taken into consideration, the electrolyte composition and detection mode was selected. This approach was found to be especially valuable for optimization of the electrolyte composition for the separation of analytes having medium mobility. Indirect conductometric detection mode was superior to the direct mode as predicted theoretically. The best performance was achieved with 150,mM 2-amino-2-methylpropanol electrolyte at pH,11.6. The separation was carried out in a counter-electroosmotic mode and completed in less than 6,min. The LODs achieved were about 2.3,3.3,,M and could be further improved to 0.12,0.17,,M by using a sample stacking procedure. The method compares well to the UV-Vis detection. [source] Inhibition of lipid peroxidation by anthocyanins, anthocyanidins and their phenolic degradation productsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 1 2007Jonathan E. Brown Abstract Food components that delay or prevent biomolecule oxidation may be relevant in shelf life extension as well as disease prevention. Anthocyanins are a potentially important group of compounds, but they are prone to degradation both in vitro and in vivo, producing simple phenols. In this study, eight structurally related (poly)phenols [anthocyan(id)ins and phenolic acids] were examined for their ability to inhibit lipid oxidation at physiologically relevant concentrations (100,1000,nM) using the Cu2+ -mediated low-density lipoprotein oxidation model. Interaction between each (poly)phenol and Cu2+ ions was also investigated. (Poly)phenols with an ortho -dihydroxy group arrangement, i.e. cyanidin-3-glucoside, cyanidin and protocatechuic acid, were the most effective within their class, extending the lag phase to oxidation by 137, 255 and 402%, respectively (at 1000,nM). At the same concentration, trihydroxy-substituted compounds (delphinidin and gallic acid) were of intermediate efficacy, extending the lag phase by 175 and 38%, respectively. Compounds with the 4'-hydroxy-3',5'-methoxy arrangement (i.e. malvidin-3-glucoside and malvidin) were the least effective (3 and 58% extension, respectively), while syringic acid (4-hydroxy-3,5-dihydroxy benzoic acid) was pro-oxidant (lag phase shortened by 31%). (Poly)phenols with the ortho -dihydroxy arrangement chelated Cu2+ ions, which in part explains their greater efficacy over the other (poly)phenols in this model oxidation system. However, differences in their hydrogen-donating properties and their partitioning between lipid and hydrophilic phases are also relevant in explaining these structure-activity relationships. [source] Effects of genotype, location and baking on the phenolic content and some antioxidant properties of cereal speciesINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2010Valeria Menga Summary In order to assess the effect of genotype, location and their interaction on total phenolic content (TPC) of chemical extracts, the whole grains of durum and soft wheat, oat, barley and triticale were evaluated. Data showed differences in phenolic content of chemical extracts among cereal species and the analysis of variance confirmed the key role of location. Besides TPC and trolox equivalent antioxidant capacity (TEAC) values assessed by chemical extraction were compared with those obtained with an in vitro digestive enzymatic extraction. Differences were found between methanolic and enzymatic extracts, and data confirmed that enzymatic technique enhanced extraction of antioxidants but pointed out lesser differences among cereal types. The breads obtained by flours enriched with different levels of bran were also evaluated. Chemical extracts highlighted the increasing levels of antioxidants according to bran enrichments, without pointing out changes caused by baking. The enzymatic extraction instead did not show differences regarding to bran enrichments, but documented a loss in antioxidant properties of breads in respect to corresponding flours. On the other hand the scarce differences between flours and corresponding breads did not allow asserting that baking modified the TPC and TEAC, independently of the extraction methods used. Indeed, during baking process, also the observed phenolic acids profile variations did not vary the antioxidant properties of breads. [source] Phenolic content and profiles of selected wild fruits of Zimbabwe: Ximenia caffra, Artobotrys brachypetalus and Syzygium cordatumINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2008A. R. Ndhlala Summary The phenolic compound content and profiles of three wild fruits found in Zimbabwe were tentatively identified using the traditional colorimetric methods and high-performance liquid chromatography (HPLC). The fruits assayed were: Ximenia caffra, Artobotrys brachypetalus and Syzygium cordatum. Ximenia caffra fruit peels contained the highest amounts of total phenolics amounting to 1205 ,g g,1 in fresh weight, flavonols amounting to 27 ,g g,1 and phenolic acids on HPLC tentative identification showed higher concentrations compared with the profiles of the other fruits. Syzygium cordatum fruit peels contained the least amounts of phenolics amounting to 20 ,g g,1, flavonols amounting to 8 ,g g,1 and phenolic acids' HPLC profiles showed low concentrations. Comparing the peels and pulps of all the fruits, we detected more total phenolics in the peels of X. caffra as high as 1205 ,g g,1 and the pulps had 228 ,g g,1, more flavonols and phenolic acids while the peels of S. cordatum fruits contained the least with a total phenolic acid content of 20 ,g g,1, and had more flavonols in the pulps than the peels, 11 ,g g,1 and 8 ,g g,1, respectively. Ximenia caffra contained 1.2% and about 1% dry weight condensed tannins in peels and pulps, respectively. In S. cordatum we detected 0.2% and 0.3% dry weight condensed tannins in the peels and pulps, respectively. [source] Decomposition of Allelopathic Plants in SoilJOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 3 2005T. D. Xuan Abstract Higher plants with strong allelopathic properties are commonly incorporated into soil for weed-control purposes. To understand the phytotoxic variation in the soil, which can be utilized for weed control through the use of allelopathic plants, the decomposition of alfalfa (Medicago sativa L. cv. Rasen) and kava (Piper methysticum L.) after soil amendment were evaluated. Both alfalfa and kava strongly inhibited barnyardgrass and monochoria growth for up to 10 days (80,100 % weed control). After 20,25 days, the magnitude of inhibition was drastically reduced, but was still effective (50 % weed control). A number of phenolic acids were detected in the soil even 50 days after incorporation in low concentration, but their concentrations reached a maximum after 10,15 days and were efficacious until 20,25 days. Phenolic acids varied between alfalfa and kava. The variations in electrical conductivity (EC) and osmotic pressure (OP) were strongly related to chemicals and toxic compounds exuded into the soil during decomposition and were proportional to the magnitude of inhibition observed, whereas pH did not appear to be correlated with inhibition. The decomposition of several unknown inhibitors present in kava was also analysed and assessed. Our findings indicate that these growth inhibitors were almost disintegrated in soil after 10 days, but strong inhibition was detected until 25 days after amendment. Results from this study demonstrate that chemicals released from allelopathic plants incorporated into soil are toxic and cause inhibition of certain species and could be exploited as a biological tool for weed management. [source] Influence of phenolic acids on growth and inactivation of Oenococcus oeni and Lactobacillus hilgardiiJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2003F.M. Campos Abstract Aims: To determine the effect of several wine-associated, phenolic acids on the growth and viability of strains of Oenococcus oeni and Lactobacillus hilgardii. Methods and Results: Growth was monitored in ethanol-containing medium supplemented with varying concentrations of hydroxybenzoic acids (p -hydroxybenzoic, protocatechuic, gallic, vanillic and syringic acids) and hydroxycinnamic acids (p -coumaric, caffeic and ferulic acids). Progressive inactivation was monitored in ethanol-containing phosphate buffer supplemented in a similar manner to the growth experiments. Hydroxycinnamic acids proved to be more inhibitory to the growth of O. oeni than hydroxybenzoic acids. On the other hand, some acids showed a beneficial effect on growth of Lact. hilgardii. p- Coumaric acid showed the strongest inhibitory effect on growth and survival of both bacteria. Conclusions: Most phenolic acids had a negative effect on growth of O. oeni, for Lact. hilgardii this effect was only noted for p- coumaric acid. Generally, O. oeni was more sensitive to phenolic acid inactivation than Lact. hilgardii. Significance and Impact of the Study: Eight wine-derived, phenolic acids were compared for their effects on wine lactic acid bacteria. Results indicate that phenolic acids have the capacity to influence growth and survival parameters. The differences found between phenolic compounds could be related to their different chemical structures. [source] Goitrogenic activity of p -coumaric acid in ratsJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 6 2003Fatima Khelifi-Touhami Abstract The effects of three natural phenolic acids (caffeic, ferulic, and p -coumaric) on the rat thyroid gland were examined in a 3-week oral-treatment study. Forty male Wistar albino rats, divided into groups of 10 rats each and fed iodine-rich diet, were administered by gastrointestinal tube saline (control), caffeic acid, ferulic acid, or p -coumaric acid at a dose level of 0.25 ,mol/kg/day for 3 weeks. The mean absolute and relative thyroid weights in caffeic, ferulic, or p -coumaric acid groups were significantly increased to 127 and 132%, 146 and 153%, or 189 and 201% compared to control value, respectively. Histological examination of the thyroids of p -coumaric acid group revealed marked hypertrophy and/or hyperplasia of the follicles. Caffeic or ferulic groups showed slight to moderate thyroid gland enlargement. Thyroid lesions in p -coumaric acid group were associated with significant increases in cellular proliferation as indicated by [3H]thymidine incorporation. In addition, the goitrogenic effect of p -coumaric acid was further confirmed by significant decreases (50%) in serum tri-iodothyronine (T3) and thyroxine (T4), and a parallel increase (90%) in serum thyroid stimulating hormone (TSH) compared to control group. These results indicate that administration of p -coumaric acid at relatively high doses induces goiter in rats. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:324,328, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10094 [source] Batch and continuous studies on treatment of pulp mill wastewater by Aeromonas formicansJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 6 2001K Gupta Abstract Batch and continuous studies have been conducted on the treatment of black liquor from a kraft pulp and paper mill by a bacterial strain, Aeromonas formicans. The results of batch studies revealed that the strain was able to remove 71% and 78% of COD and lignin respectively, while the colour removal efficiency was around 86% in 10 days of retention time. The analysis of lignin degradation products by gas chromatography after 20 days of incubation revealed the formation of some phenolic acids, which were responsible for the decrease in pH during batch studies. The removal efficiencies of COD, colour and lignin obtained in continuous reactor studies were 73, 88 and 77% respectively for an 8 day detention period and these efficiencies were almost the same as obtained in batch studies. © 2001 Society of Chemical Industry [source] CHANGES IN MAJOR ANTIOXIDANT COMPOUNDS DURING AGING OF TRADITIONAL BALSAMIC VINEGARJOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2010ELENA VERZELLONI ABSTRACT Traditional balsamic vinegar (TBV) shows antioxidant capacity that increases passing from cask 5, containing the youngest vinegar, to cask 1 containing the oldest vinegar. This increase in antioxidant capacity is a consequence of both the concentration of compounds already present and of new antioxidants formation and is positively related to the increase in the polyphenolic content and in the Maillard reaction/caramellization products. During TBV aging, some reactions involving flavonoids and tannins take place. Tannins can undergo acid-catalyzed cleavage of their interflavonoid bonds with subsequent condensation of other flavonoid molecules. In addition, the low pH, the decrease of the water content and the presence of aldehydes, may promote flavonoids polycondensation. These reactions explain the observed increase in polymeric phenolic compounds and the decrease in monomeric flavonoids. During TBV aging an increase in the browning index is observed as a consequence of the polycondensation reactions of flavonoids and of brown melanoidins accumulation. PRACTICAL APPLICATIONS Traditional balsamic vinegar is a potentially healthy seasoning with high antioxidant capacity that increases during the aging resulting in a product with a strong antioxidant capacity and rich in phenolic compounds such as phenolic acids, monomeric catechins, flavonols and tannins. It also contains other antioxidants such as melanoidins derived from the Maillard and caramelization reaction that occur during must boiling and traditional balsamic vinegar aging. Independently of their bioavailability, traditional balsamic vinegar can contribute to supply antioxidant molecules that play an important role in protecting the gastrointestinal tract itself against peroxidation, thereby limiting the formation of detrimental lipid degradation products. [source] ANTIOXIDANT ACTIVITY AND PHENOLIC ACID CONSTITUENTS OF CHESTNUT (CASTANIA SATIVA MILL.) HONEY AND PROPOLISJOURNAL OF FOOD BIOCHEMISTRY, Issue 4 2009ALI OSMAN SARIKAYA ABSTRACT This study describes the constituents of phenolic acids and antioxidant activities of chestnut (Castania sativa Mill.) honeys and propolis in Turkey. Antioxidant activity of the chestnut honeys and propolis were examined by three different methods, namely scavenging of free radical 2, 2-diphenyl-1-picrylhydrazyl, FRAP, and cupric reducing antioxidant power. Total phenolic contents were determined by using Folin,Ciocalteu reagent as GA equivalent. The phenolic constituents were also determined by HPLC. The antioxidant activities were compared with standard antioxidants such as catechin, BHT and Trolox. The antioxidant activities of all the samples were found high and related to the sample concentrations. The ethanolic propolis extracts showed the highest antioxidant activity. The major phenolic acids of the chestnut honeys and propolis identified by HPLC with PDA detection were coumaric acid, FA, cinnamic acid, CA and ChA. PRACTICAL APPLICATIONS In this study, some phenolic acid components and antioxidant capacity of chestnut (Castania sativa Mill.) honey and propolis were measured. The comparative findings from antioxidant activities and phenolic acid analyses of honey and propolis samples of chestnut origin provide important criteria for considering their nutritional and nutraceutical potentials. Comparison of our results with literature data also ranks the chestnut honey and propolis as better sources of antioxidants among those from other floral origins. [source] BIOCHEMICAL CHARACTERIZATION OF BORAGE (BORAGO OFFICINALIS L.) SEEDSJOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2009BAYA MHAMDI ABSTRACT Gas chromatography,mass spectrometry analysis of seed Borago officinalis essential oil (EO) revealed the presence of 16 volatile components. ,-Caryophyllene (26%) and p-cymene-8-ol (19.7%) represented the major components, while nonadecane (0.7%) and hexanol (0.7%) were the minor ones. The EO composition was characterized by higher abundance of oxygenated monoterpenes (27.7%), followed by sesquiterpenes (26%). Fatty acid composition showed the predominance of linoleic (35.4%), oleic (24.2%) and ,-linolenic (20.4%) acids. Polyphenols were analyzed by reversed-phase high-performance liquid chromatography after acid hydrolysis of phenolic acid esters. Six phenolic acids were identified in seed extract and rosmarinic acid was the predominant one with 1.65 mg/g dry matter weight equivalent to 33% of total phenolic acids. PRACTICAL APPLICATIONS Borage (Borago officinalis L.) is of great interest because of its medicinal and nutritional properties. In fact, thanks to its characteristic composition in fatty acids, particularly high levels of gamma-linolenic acid in its seed oil, borage has gained importance. The potent consumers of this medicinal plant are hypertensive and hypercholesterolemic people. Borage consumption is also recommended for people suffering from rheumatism and eczema. Unfortunately, the knowledge about antioxidative/antiradical properties of borage is very scanty. So, recently, an extensive investigation was focused on the antioxidant properties of borage extracts. These extracts showed excellent antioxidant properties and their effects were attributed to their phenolic constituents. These antioxidants can be concentrated, either as crude extracts or individual phenolic compounds, to be used in highly unsaturated oils such as marine oils. Furthermore, borage consumption has been reported as a possible gastric cancer protective factor. [source] RECOVERY OF SINAPIC ACID FROM A WASTE STREAM IN THE PROCESSING OF YELLOW MUSTARD PROTEIN ISOLATEJOURNAL OF FOOD PROCESS ENGINEERING, Issue 2 2008N. PRAPAKORNWIRIYA ABSTRACT A large amount of waste permeates generated from the processing of yellow mustard protein was concentrated fivefold using a nanofilter with a molecular weight cut off of 1,000 Da, while approximately 74% of sinapic acid was retained. Sinapic acid was then released from sinapine, its esterified form, by an alkaline hydrolysis. The hydrolyzed solution was acidified to prevent oxidation of the sinapic acid and to precipitate the remaining proteins. Subsequently, sinapic acid and other phenolics were extracted by a two-stage extraction using a mixture of diethyl ether and ethyl acetate (1:1), 165-min extraction time and permeate-to-solvent ratio of 1:2. Approximately 95% of the sinapic acid in the acidified permeate was finally concentrated in the solvent phase. PRACTICAL APPLICATIONS This development has led to an economical process to recover phenolics and to treat effluent from a process of oilseed protein while reducing the use of water during the extraction of protein. A reduction of water usage makes the processing of oilseed protein isolate more economically attractive, and the recovered phenolics may find a use as a nutraceutical. The developed process is not only limited to the recovery of phenolics from mustard, but also applied for recovering phenolic acids, specifically sinapic acid, from waste water from membrane processing of protein from mustard and similar polyphenol-containing oilseeds. [source] Effect of Maturity Stages and Drying Methods on the Retention of Selected Nutrients and Phytochemicals in Bitter Melon (Momordica charantia) LeafJOURNAL OF FOOD SCIENCE, Issue 6 2009Min Zhang ABSTRACT:, The purpose of this study was to investigate the nutrient and phytochemical composition of bitter melon leaves under varying maturity levels and drying techniques. Fresh, oven-dried, and freeze-dried leaves were evaluated over 3 maturity stages. In fresh leaves at various stages, crude fat, crude protein, and soluble dietary fiber contents ranged from 4.2% to 13.6%, 6.4% to 23.1%, and 0.04% to 3.50% on dry-weight basis, respectively. The contents of K, Ca, Mg, Fe, and Zn ranged from 1850.8 to 2811.8, 837.4 to 4978.2, 317.3 to 512.4, 8.4 to 16.7, and 4.1 to 5.9 mg/100 g dry-weight basis, respectively. Vitamin C, ,-carotene, and lutein contents ranged from 397.4 to 1275.1, 154.2 to 422.8, and 737.6 to 1304.6 ,g/g dry-weight basis. The major flavonoids and phenolic acids were rutin, gentistic acid, and,o -coumaric acid, which ranged from 7.57 to 12.75, 2.53 to 10.11, and 4.24 to 9.75 mg/g dry-weight basis, respectively. In oven-dried samples, 40.2% to 52.3% of vitamin C, 35.4% to 55.4% of ,-carotene, 25.6% to 71.6% of lutein, 26.4% to 84.0% of rutin, trace to 11.4% of gentistic acid, and 7.4% to 46.6% of,o -coumaric acid were retained, while the retainment ratios of these components in freeze-dried samples were 84.7% to 99.0%, 76.4% to 99.3%, 90.4% to 96.1%, 39.8% to 99.3%, 24.1% to 68.4%, and 75.8% to 87.0%, respectively. The data showed that freeze-drying better preserves the nutrient and phytochemical quality of bitter melon leaves in comparison to oven-drying. Bitter melon leaf is a rich source of selected nutrients and phytochemicals. [source] | ||||||||||||||||||||||||||||||||||