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https://www.readbyqxmd.com/read/28437688/application-of-near-infrared-spectroscopy-for-the-rapid-quality-assessment-of-radix-paeoniae-rubra
#1
Hao Zhan, Jing Fang, Liying Tang, Hongjun Yang, Hua Li, Zhuju Wang, Bin Yang, Hongwei Wu, Meihong Fu
Near-infrared (NIR) spectroscopy with multivariate analysis was used to quantify gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra, and the feasibility to classify the samples originating from different areas was investigated. A new high-performance liquid chromatography method was developed and validated to analyze gallic acid, catechin, albiflorin, and paeoniflorin in Radix Paeoniae Rubra as the reference. Partial least squares (PLS), principal component regression (PCR), and stepwise multivariate linear regression (SMLR) were performed to calibrate the regression model...
April 20, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28436036/oxidative-behavior-of-catechin-in-the-presence-of-inactive-dry-yeasts-a-comparison-with-sulfur-dioxide-ascorbic-acid-and-glutathione
#2
Piergiorgio Comuzzo, Rosanna Toniolo, Franco Battistutta, Marion Lizee, Rossella Svigelj, Roberto Zironi
BACKGROUND: The antioxidant capacity of an inactive dry yeast preparation (YD) was investigated by conventional analytical methods (spectrophotometry, HPLC) as well as by cyclic voltammetry (CV), in a (+)-catechin model wine and compared with certain of the most common antioxidants found in wine: sulfur dioxide, ascorbic acid and glutathione. RESULTS: Sulfur dioxide (SO2 ) was the highest performing substance in protecting (+)-catechin against browning, followed by ascorbic acid and the YD preparation...
April 24, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28428085/galloylation-of-polyphenols-alters-their-biological-activity
#3
REVIEW
Daniel Karas, Jitka Ulrichová, Kateřina Valentová
Polyphenols form one of the largest groups of natural compounds and possess a wide range of biological properties. These activities can be influenced by the galloyl moiety within their structures. A multitude of galloylated polyphenolic compounds occurs in nature, but galloylated phenols are also produced synthetically to influence their biological properties. This review provides a comprehensive summary of current knowledge about natural (galloylated catechins, theaflavins and proanthocyanidins, penta-O-galloyl-β-D-glucose, gallotannins, ellagitannins, ellagic acid and flavonols) and semisynthetic gallates with a focus on their biological activity and toxicity issues...
April 17, 2017: Food and Chemical Toxicology
https://www.readbyqxmd.com/read/28428039/antimicrobial-mechanism-of-epigallocatechin-gallate-and-gallocatechin-gallate-they-target-1-deoxy-d-xylulose-5-phosphate-reductoisomerase-the-key-enzyme-of-the-mep-terpenoid-biosynthetic-pathway
#4
Xian Hui, Shui-Hong Hua, Qian-Qian Wu, Heng Li, Wen-Yun Gao
The catechins EGCG and GCG show a variety of pharmacological activities, especially an antibacterial capacity, but their modes of antimicrobial action have not been fully elucidated. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), the first key enzyme in the MEP pathway for terpenoid biosynthesis, is a recently validated antimicrobial target. In order to disclose the antibacterial mechanism of EGCG and GCG, the DXR inhibitory activity of them was investigated in this study. The data show that EGCG and GCG both could specifically suppress the activity of DXR, with EGCG exhibiting relatively low effect against DXR (IC50 about 210 μM) and GCG displaying strong activity (IC50 27...
April 18, 2017: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28422543/newer-insights-into-the-antidiarrheal-effects-of-acacia-catechu-willd-extract-in-guinea-pig
#5
Matteo Micucci, Roberto Gotti, Ivan Corazza, Gabriella Tocci, Alberto Chiarini, Marta De Giorgio, Luca Camarda, Maria Frosini, Carla Marzetti, Monica Cevenini, Roberta Budriesi
Acacia catechu Willd. is a plant diffused in India and other Asian countries, where it is used as a traditional medicine for the treatment of several ailments including diarrhea, one of the most common pathologies worldwide. In this study, we determined the chemical composition of Acacia catechu Willd. extract (AC) and evaluated its effect on spontaneous and induced contractility in isolated guinea pig ileum and proximal colon. Preliminary data about its antimicrobial effect against some pathogen agents versus some microbiota intestinal strain have been also reported...
April 19, 2017: Journal of Medicinal Food
https://www.readbyqxmd.com/read/28422389/triosephosphate-isomerase-tyrosine-nitration-induced-by-heme-nano2-h2-o2-or-peroxynitrite-effects-of-different-natural-phenolic-compounds
#6
Wanxia Gao, Jie Zhao, Hailing Li, Zhonghong Gao
Peroxynitrite and heme peroxidases (or heme)-H2 O2 -NaNO2 system are the two common ways to cause protein tyrosine nitration in vitro, but the effects of antioxidants on reducing these two pathways-induced protein nitration and oxidation are controversial. Both nitrating systems can dose-dependently induce triosephosphate isomerase (TIM) nitration, however, heme-H2 O2 -NaNO2 was less destructive to protein secondary structures and led to more nitrated tyrosine residue than 3-morpholinosydnonimine hydrochloride (SIN-1, a peroxynitrite donor)...
April 19, 2017: Journal of Biochemical and Molecular Toxicology
https://www.readbyqxmd.com/read/28421745/molecular-approach-of-the-synergistic-effect-on-astringency-elicited-by-mixtures-of-flavanols
#7
Alba M Ramos-Pineda, Ignacio García-Estévez, Natércia Fernandes Brás, Eva M Martin Del Valle, Montserrat Duenas, M Teresa Escribano-Bailon
The interactions between salivary proteins and wine flavanols (catechin, epicatechin and mixtures catechin+epicatechin) have been studied by HPLC-DAD, Isothermal Titration Microcalorimetry and Molecular Dynamics simulations. Chromatographic results suggest that the presence of these flavanol mixtures could facilitate the formation of precipitates to the detriment of soluble aggregates. The comparison between the thermodynamic parameters obtained showed remarkable higher negative values of ΔG in the system containing the mixture of both flavanols in comparison to the systems containing individual flavanols, indicating a more favourable scenario in the mixing system...
April 19, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28417084/antioxidant-antimicrobial-activity-and-bioactive-compounds-of-bergenia-ciliata-sternb-a-valuable-medicinal-herb-of-sikkim-himalaya
#8
Mithilesh Singh, Neha Pandey, Vasudha Agnihotri, K K Singh, Anita Pandey
Bergenia ciliata Sternb., commonly known as Paashaanbhed, is a well known herb of Sikkim Himalaya with various pharmaceutical properties. However, scientific exploration of B. ciliata, growing in the Sikkim Himalaya, for phytochemicals and pharmacological properties is in infancy. With this view, the present study was undertaken to investigate B. ciliata leaf extracts for antioxidant, antimicrobial activity and bioactive compounds. Three solvents viz., methanol, ethyl acetate and hexane were used for extraction and the respective leaf extracts were analyzed for total phenolic and flavonoid contents along with the antioxidant and antimicrobial activities...
April 2017: Journal of Traditional and Complementary Medicine
https://www.readbyqxmd.com/read/28416872/impact-of-light-irradiation-on-black-tea-quality-during-withering
#9
Zeyi Ai, Beibei Zhang, Yuqiong Chen, Zhi Yu, Huacai Chen, Dejiang Ni
Black tea manufacture usually involves the processes of withering, cutting, fermentation and drying. The aim of present study was to evaluate the effect of the relationship between the quality and withering with different light sources (ultraviolet, yellow, blue, purple, orange, red, cyan, green and white) an quality attribute of tea. The results indicated that the yellow, orange and red light withering significantly improved the aroma and taste, imparting the tea a sweet flavor and a fresh and mellow taste...
April 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28416871/effect-of-water-quality-on-the-main-components-in-fuding-white-tea-infusions
#10
Haihua Zhang, Yulan Jiang, Yangjun Lv, Junxian Pan, Yuwei Duan, Yunyun Huang, Yuejin Zhu, Shikang Zhang, Kunkun Geng
The aim of this study was to investigate the effect of water quality on the main components in Fuding white tea infusions, including catechins, caffeine, theanine and free amino acids. Pure, tap and spring water were tested, and water quality was found to have a distinct effect on the main compounds extracted. Pure water, which was weakly acidic and low in dissolved ions, achieved the highest catechin content, whereas caffeine and theanine, and amino acids, were higher in infusions made with spring and tap water, respectively...
April 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28416859/effect-of-catechin-and-its-derivatives-on-inhibition-of-polyphenoloxidase-and-melanosis-of-pacific-white-shrimp
#11
Thanasak Sae-Leaw, Soottawat Benjakul, Benjamin K Simpson
This study aimed to investigate the effect of tea catechin (C) and 4 of its derivatives on the Pacific white shrimp PPO inhibition and melanosis during refrigerated storage. Epigallocatechin gallate (EGCG) exhibited the highest inhibition towards PPO, followed by C. Inhibitory activity of all compounds tested was in a dose dependent manner (0.1-2.0 mM). Based on activity staining, EGCG most effectively inhibited PPO. For inhibition kinetic studies, C and epicatechin (EC) showed uncompetitive type, whereas epicatechin gallate (ECG), epigallocatechin (EGC) and EGCG exhibited mixed type inhibition...
April 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28416338/separation-and-purification-of-polyphenols-from-red-wine-extracts-using-high-speed-counter-current-chromatography
#12
Yuanyuan Li, Lingxi Li, Yan Cui, Shuting Zhang, Baoshan Sun
Polyphenols are important compounds of red wine owing to their contribution to sensory properties and antioxidant activities. In this study, high-speed counter-current chromatography (HSCCC) coupled with semi-preparative HPLC was used for large-scale separation and purification of polyphenols from red wine extracts. With the solvent system of hexane-ethyl acetate-water (1-50-50), various oligomeric procyanidins including monomer catechin, epicatechin, dimers B1, B2; phenolic acids including coutaric acid, caftaric acid and other type of polyphenols were largely separated within 370min and most of these compounds presented high yields (0...
March 12, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28415774/chemoprevention-of-prostate-cancer-in-men-with-high-grade-prostatic-intraepithelial-neoplasia-hgpin-a-systematic-review-and-adjusted-indirect-treatment-comparison
#13
Kang Cui, Xiangnan Li, Yabing Du, Xiance Tang, Seiji Arai, Yiwei Geng, Ying Xi, Han Xu, Yue Zhou, Wang Ma, Tengfei Zhang
BACKGROUND: High-grade prostatic intraepithelial neoplasia (HGPIN) is the precursor or premalignant form of prostate cancer. At least 30% patients with a confirmed HGPIN will develop prostate cancer within 1 year after repeated biopsy. HGPIN patients are the appropriate at-risk population for chemoprevention strategies investigation against prostate cancer. However the commonly used chemoprevention agents that targeted on hormonal imbalance or lifestyle-related factors showed varied results in HGPIN patients...
March 15, 2017: Oncotarget
https://www.readbyqxmd.com/read/28412883/polyphenols-of-virgin-coconut-oil-prevent-pro-oxidant-mediated-cell-death
#14
Soorya Parathodi Illam, Arunaksharan Narayanankutty, Achuthan C Raghavamenon
Virgin coconut oil (VCO), extracted from the fresh coconut kernel, is a food supplement enriched with medium chain saturated fatty acids and polyphenolic antioxidants. It is reported to have several health benefits including lipid lowering, antioxidant and anti-inflammatory activities. The pharmacological benefits of VCO have been attributed to its polyphenol contents (VCOP), the mechanistic basis of which is less explored. LC/MS analysis of VCOP documented the presence of gallic acid, ferulic acid, quercetin, methyl catechin, dihydrokaempferol, and myricetin glycoside...
April 16, 2017: Toxicology Mechanisms and Methods
https://www.readbyqxmd.com/read/28412808/spontaneously-assembled-nano-aggregates-in-clear-green-tea-infusions-from-camellia-ptilophylla-and-camellia-sinensis
#15
Xiaorong Lin, Xiong Gao, Zhongzheng Chen, Yuanyuan Zhang, Wei Luo, Xiaofei Li, Bin Li
Tea nano-aggregates spontaneously assembled in clear tea infusions are considered as the precursors of tea cream, though their molecular basis remains obscure. Here, we characterized nano-aggregates in green tea infusions from Camellia ptilophylla, a peculiar tea variety with 6.0% of theobromine, and Camellia sinensis as the control for comparative purpose. Numerous negatively-charged spherical colloidal particles of 50-100 nm in diameter were primarily found in both green tea infusions. Catechins, proteins and carbohydrates were confirmed as the dominant components in green tea nano-aggregates...
April 15, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28409937/spatial-and-temporal-localization-of-flavonoid-metabolites-in-strawberry-fruit-fragaria-%C3%A3-ananassa
#16
Anna C Crecelius, Dirk Hölscher, Thomas Hoffmann, Bernd Schneider, Thilo C Fischer, Magda-Viola Hanke, Henryk Flachowsky, Wilfried Schwab, Ulrich S Schubert
Flavonoids are important metabolites in strawberries (Fragaria × ananassa) because they accomplish an extensive collection of physiological functions and are valuable for human health. However, their localization within the fruit tissue has not been extensively explored. Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was employed to shed light on the spatial distribution of flavonoids during fruit development. One wild-type (WT) and two transgenic lines were compared, wherein the transgenic enzymes anthocyanidin reductase (ANRi) and flavonol synthase (FLSi), respectively, were down-regulated using an RNAi-based silencing approach...
April 24, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28407961/bionic-multi-tentacled-ionic-liquid-modified-silica-gel-for-adsorption-and-separation-of-polyphenols-from-green-tea-camellia-sinensis-leaves
#17
Wei Zhang, Xueting Feng, Yohannes Alula, Shun Yao
For the first time, a new kind of bionic multi-tentacled ionic liquid-modified silica gel was synthesized and used as selective adsorbent in the preparative separation of tea polyphenols (TP) from green tea leaves. It was found that silica particles with polyvinyl alcohol chains modified by N-methyl imidazole proline salt (PVA·Im(+)·Pro(-)@SiO2) had the excellent performance in selective adsorption as well as fine separation for target compounds. The new adsorbent exhibited high adsorption capacity and good reusability, meanwhile the antioxidant activity of TP could be improved through its efficient enrichment...
September 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28407906/antioxidant-and-antibiofilm-activities-of-secondary-metabolites-from-ziziphus-jujuba-leaves-used-for-infusion-preparation
#18
Silvia Damiano, Martino Forino, Arpan De, Luca A Vitali, Giulio Lupidi, Orazio Taglialatela-Scafati
Ziziphus jujuba Mill., jujube, leaf infusions are popular bedtime beverages as they improve sleep by soothing the nerves. With the aim of providing further insights into the polyphenol content of jujube leaf infusion and their antioxidant activities, a 2,2-diphenyl-1-picrylhydrazyl (DPPH)-guided purification of the aqueous extract of Z. jujuba Mill. leaves was conducted. Three major antioxidant polyphenols (i.e. quercitrin, catechin and gallocatechin) of the leaves were identified. In addition, a significant antibiofilm bioactivity against Streptococcus mutans, a causative agent of human dental caries, was detected for the aqueous leaf extract and its bio-guided separation resulted in the identification of the lupane triterpenoid alphitolic acid as the main antibiofilm metabolite...
September 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28400479/a-presurgical-study-of-lecithin-formulation-of-green-tea-extract-in-women-with-early-breast-cancer
#19
Matteo Lazzeroni, Aliana Guerrieri-Gonzaga, Sara Gandini, Harriet Johansson, Davide Serrano, Massimiliano Cazzaniga, Valentina Aristarco, Debora Macis, Serena Mora, Pietro Caldarella, Gianmatteo Pagani, Giancarlo Pruneri, Antonella Riva, Giovanna Petrangolini, Paolo Morazzoni, Andrea DeCensi, Bernardo Bonanni
Epidemiologic data support an inverse association between green tea intake and breast cancer risk. Greenselect®Phytosome® (GSP) is a lecithin formulation of a caffeine-free green tea catechin extract. The purpose of the study was to determine the tissue distribution of Epigallocatechin-3-O-gallate (EGCG) and its effect on cell proliferation and circulating biomarkers in breast cancer patients. Twelve early BC patients received GSP 300 mg, equivalent to 44.9 mg of EGCG, daily for 4 weeks prior to surgery. The EGCG levels were measured before (free-) and after (total-) enzymatic hydrolysis by HPLC-MS/MS in plasma, urine, breast cancer tissue and surrounding normal breast tissue...
April 11, 2017: Cancer Prevention Research
https://www.readbyqxmd.com/read/28391711/phenolic-content-and-antioxidant-properties-of-seeds-from-different-grape-cultivars-grown-in-iran
#20
Vasigheh Sadat Mirbagheri, Ebrahim Alizadeh, Mostafa Yousef Elahi, Sedigheh Esmaeilzadeh Bahabadi
This study investigated the antioxidant activity and phenolic composition of seed extracts from three grape cultivars grown in Iran. Folin Ciocalteu method was used for the determination of the total phenolic contents and GC-MS was used for the analysis of phenolic compositions. 1,1-diphenyl-2-picrylhydrazyl (DPPH) method was used to evaluate the antioxidant activity. The highest and the lowest total phenolic contents of seed extract were found in the black and green grape, respectively. The content of individual phenols such as Frulic acid, Gentistic acid, Syringic acid, (+) Catechin, Chlorogenic acid and (-)- Epicatchin gallate was cultivars dependent...
April 10, 2017: Natural Product Research
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