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https://www.readbyqxmd.com/read/28635261/novel-protein-based-solid-biosensor-for-determining-pro-oxidant-activity-of-phenolic-compounds
#1
Esin Akyüz, Kevser Sözgen Başkan, Esma Tütem, Reşat Apak
To develop a protein‒based biosensor measuring the pro-oxidant activities of phenolic compounds, egg white proteins were precipitated with calcium chloride to obtain an insoluble calcium proteinate complex. This biosensor was used for the determination of Cu(II)‒induced pro-oxidant activity of antioxidants such as gallic acid, catechin, epicatechin, quercetin, chlorogenic acid and myricetin, and ascorbic acid. This assay involved the reduction of Cu(II) ions to Cu(I) by antioxidant compounds (simultaneously giving rise to reactive oxygen species) and binding of the formed Cu(I) to the solid biosensor...
June 21, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28630292/tetrahydrobiopterin-regulates-monoamine-neurotransmitter-sulfonation
#2
Ian Cook, Ting Wang, Thomas S Leyh
Monoamine neurotransmitters are among the hundreds of signaling small molecules whose target interactions are switched "on" and "off" via transfer of the sulfuryl-moiety (-SO3) from PAPS (3'-phosphoadenosine 5'-phosphosulfate) to the hydroxyls and amines of their scaffolds. These transfer reactions are catalyzed by a small family of broad-specificity enzymes-the human cytosolic sulfotransferases (SULTs). The first structure of a SULT allosteric-binding site (that of SULT1A1) has recently come to light. The site is conserved among SULT1 family members and is promiscuous-it binds catechins, a naturally occurring family of flavanols...
June 19, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28624083/effect-of-the-type-of-brewing-water-on-the-chemical-composition-sensory-quality-and-antioxidant-capacity-of-chinese-teas
#3
Yong-Quan Xu, Chun Zou, Ying Gao, Jian-Xin Chen, Fang Wang, Gen-Sheng Chen, Jun-Feng Yin
The physicochemical characteristics, sensory quality, and antioxidant activity of tea infusions prepared with purified water (PW), mineral water (MW), mountain spring water (MSW), and tap water (TW) from Hangzhou were investigated. The results showed that the taste quality, catechin concentration, and antioxidant capacity of green, oolong, and black tea infusions prepared using MW and TW were significantly lower than those prepared using PW. Extraction of catechins and caffeine was reduced with high-conductivity water, while high pH influenced the stability of catechins...
December 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28622602/assessment-of-the-phenolic-profile-antimicrobial-activity-and-oxidative-stability-of-transgenic-perilla-frutescens-l-overexpressing-tocopherol-methyltransferase-%C3%AE-tmt-gene
#4
Bimal Kumar Ghimire, Chang Yeon Yu, Ill-Min Chung
This study evaluated the effects of enhanced concentrations of α-tocopherol and phenolic compounds on the resistance and stability of Perilla oil in transgenic Perilla frutescens plants against various tested pathogenic bacteria by over-expressing the γ-tmt gene. The concentration of phenolic compounds in the non-transgenic samples was 9313.198 ± 18.887 μg g(-1) dry weight (DW), whereas the total concentration of the transgenic samples ranged from 9118.015 ± 18.822 to 10527.612 ± 20.411 μg g(-1) DW...
June 7, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28618113/the-mechanism-of-interactions-between-tea-polyphenols-and-porcine-pancreatic-alpha-amylase-analysis-by-inhibition-kinetics-fluorescence-quenching-differential-scanning-calorimetry-and-isothermal-titration-calorimetry
#5
Lijun Sun, Michael J Gidley, Fredrick J Warren
SCOPE: This study aims to use a combination of biochemical and biophysical methods to derive greater mechanistic understanding of the interactions between tea polyphenols and porcine pancreatic α-amylase (PPA). METHODS AND RESULTS: The interaction mechanism was studied through fluorescence quenching (FQ), differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC) and compared with inhibition kinetics. The results showed that a higher quenching effect of polyphenols corresponded to a stronger inhibitory activity against PPA...
June 15, 2017: Molecular Nutrition & Food Research
https://www.readbyqxmd.com/read/28615861/in-vitro-ovicidal-activity-of-peganum-harmala-seeds-extract-on-the-eggs-of-fasciola-hepatica
#6
Mohammad Moazeni, Zahra Sadat Saadaty Ardakani, Mohammad Jamal Saharkhiz, Jafar Jalaei, Ali Asghar Khademolhoseini, Shahab Shams Esfand Abad, Amir Mootabi Alavi
Peganum harmala seeds extract has been previously reported to have antimicrobial and other medicinal properties. The aim of this study was to evaluate the ovicidal activity of the methanolic extract of P. harmala seeds against the eggs of F. hepatica. The phenolic compounds of the methanolic extract of P. harmala seeds were identified by HPLC analysis. Catechin, rutin, p-Coumaric acid, chloregenic acid and hesperetin were found to be the major phenolic compounds. F. hepatica eggs were collected from the gall bladder of naturally infected sheep...
June 2017: Journal of Parasitic Diseases: Official Organ of the Indian Society for Parasitology
https://www.readbyqxmd.com/read/28612024/the-potential-of-a-brown-microalga-cultivated-in-high-salt-medium-for-the-production-of-high-value-compounds
#7
Saoussan Boukhris, Khaled Athmouni, Ibtissem Hamza-Mnif, Rayda Siala-Elleuch, Habib Ayadi, Moncef Nasri, Alya Sellami-Kamoun
Amphora sp. was isolated from the Sfax Solar Saltern and cultivated under hypersaline conditions. It contains moderate rates of proteins, lipids, sugars, and minerals and a prominent content of bioactive compounds: polyphenols, chlorophyll a, carotenoids, and fatty acids. The analysis of fatty acids with GC/MS showed that the C16 series accounted for about 75% of Amphora sp. lipids. Saturated fatty acids whose palmitic acid was the most important (27.41%) represented 41.31%. Amphora sp. was found to be rich in monounsaturated fatty acids with dominance of palmitoleic acid...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28611670/identification-of-epigallocatechin-3-gallate-as-an-inhibitor-of-phosphoglycerate-mutase-1
#8
Xiaoguang Li, Shuai Tang, Qian-Qian Wang, Elaine L-H Leung, Hongyue Jin, Yongzhuo Huang, Jia Liu, Meiyu Geng, Min Huang, Shengtao Yuan, Xiao-Jun Yao, Jian Ding
Targeting metabolic enzymes is believed to provide new therapeutic opportunities for cancer therapy. Phosphoglycerate mutase 1 (PGAM1) is a glycolytic enzyme that importantly coordinates glycolysis, pentose phosphate pathway (PPP) flux and serine biosynthesis in cancer cells and hence gains increasing interest of inhibitor discovery. Only few PGAM1 inhibitors have been reported and the molecular potency remains very limited. In an effort to discover new PGAM1 inhibitors, we carried out a biochemical assay-based screen that was focused on natural products derived small molecule compounds...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28608836/evaluation-of-the-antidiabetic-activity-and-chemical-composition-of-geranium-collinum-root-extracts-computational-and-experimental-investigations
#9
Sodik Numonov, Salamet Edirs, Khayrulla Bobakulov, Muhammad Nasimullah Qureshi, Khurshed Bozorov, Farukh Sharopov, William N Setzer, Haiqing Zhao, Maidina Habasi, Mizhgona Sharofova, Haji Akber Aisa
The root of Geranium collinum Steph is known in Tajik traditional medicine for its hepatoprotective, antioxidant, and anti-inflammatory therapeutic effects. The present study was conducted to evaluate of potential antidiabetic, antioxidant activities, total polyphenolic and flavonoid content from the different extracts (aqueous, aqueous-ethanolic) and individual compounds isolated of the root parts of G. collinum. The 50% aqueous-ethanolic extract possesses potent antidiabetic activity, with IC50 values of 0...
June 13, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28607618/catechin-and-epicatechin-reduce-mitochondrial-dysfunction-and-oxidative-stress-induced-by-amiodarone-in-human-lung-fibroblasts
#10
Luciana Fernandes Silva Santos, Adriana Stolfo, Caroline Calloni, Mirian Salvador
BACKGROUND: Amiodarone (AMD) and its metabolite N-desethylamiodarone can cause some adverse effects, which include pulmonary toxicity. Some studies suggest that mitochondrial dysfunction and oxidative stress may play a role in these adverse effects. Catechin and epicatechin are recognized as important phenolic compounds with the ability to decrease oxidative stress. Therefore, the aim of this study was to evaluate the potential of catechin and epicatechin to modulate mitochondrial dysfunction and oxidative damage caused by AMD in human lung fibroblast cells (MRC-5)...
June 2017: Journal of Arrhythmia
https://www.readbyqxmd.com/read/28606566/quantitative-proteomic-analysis-reveals-the-role-of-tea-polyphenol-egcg-in-egg-whites-in-response-to-vanadium-stress
#11
Jianping Wang, Xue Bai, Xuemei Ding, Shiping Bai, Qiufeng Zeng, Xiangbing Mao, Keying Zhang
OBJECTIVES: Tea polyphenol (TP) epigallo-catechin-3-gallate (EGCG) can alleviate vanadium (V) stress in laying hens; however, our understanding of the molecular mechanisms and proteomic changes occurring in the egg albumen remains limited. The aim of the present study is to better understand the response in layers under V challenge and mechanism of EGCG detoxification. METHOD: We divided 120 layers into four treatments in the absence and presence of 130 mg/kg EGCG, supplemented with either 0 or 5 mg/kg V...
July 2017: Nutrition
https://www.readbyqxmd.com/read/28605826/inhibition-of-hazardous-compound-formation-in-muscle-foods-by-antioxidative-phytophenols
#12
REVIEW
Youling L Xiong
Individual and mixed herbal extracts, as well as plant spices, are widely used in the preparation of muscle foods to enhance the organoleptic attributes. Abundantly rich in phenolic compounds, many of the phytochemical extracts have been shown to possess strong radical-scavenging and metal ion-binding properties and hence exert antioxidant activity in meat products. Because of their antiradical nature, phenolic acids and flavonoids, such as tea catechins, caffeic acid, chlorogenic acid, and mixed polyphenols derived from rosemary, licorice, and other herbal materials, are capable of inhibiting the formation of harmful secondary products from oxidized lipids and proteins...
June 12, 2017: Annals of the New York Academy of Sciences
https://www.readbyqxmd.com/read/28605321/antioxidant-and-enzyme-inhibitory-activities-of-extracts-from-wild-mushroom-species-from-turkey
#13
Gokhan Zengin, Mehmet Cemil Uren, Mehmet Sefa Kocak, Halil Gungor, Marcello Locatelli, Abdurrahman Aktumsek, Cengiz Sarikurkcu
The antioxidant and inhibitory effects of methanol and aqueous extracts from Hymenogaster aromaticus, Ramaria aurea, and Rhizopogon luteolus against cholinesterase, tyrosinase, α-amylase, and α-glucosidase are reported here, to our knowledge for the first time. Antioxidant activities were investigated using different assays, including 2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), ferric ion-reducing antioxidant power, cupric ion-reducing antioxidant capacity, phosphomolybdenum, and metal-chelating assays...
2017: International Journal of Medicinal Mushrooms
https://www.readbyqxmd.com/read/28603626/physiologically-based-pharmacokinetic-modeling-of-tea-catechin-mixture-in-rats-and-humans
#14
Francis C P Law, Meicun Yao, Hui-Chang Bi, Stephen Lam
Although green tea (Camellia sinensis) (GT) contains a large number of polyphenolic compounds with anti-oxidative and anti-proliferative activities, little is known of the pharmacokinetics and tissue dose of tea catechins (TCs) as a chemical mixture in humans. The objectives of this study were to develop and validate a physiologically based pharmacokinetic (PBPK) model of tea catechin mixture (TCM) in rats and humans, and to predict an integrated or total concentration of TCM in the plasma of humans after consuming GT or Polyphenon E (PE)...
June 2017: Pharmacology Research & Perspectives
https://www.readbyqxmd.com/read/28602091/assessing-spatial-variability-of-grape-skin-flavonoids-at-the-vineyard-scale-based-on-plant-water-status-mapping
#15
Luca Brillante, Johann Martinez-Luscher, Runze Yu, Cassandra M Plank, Luis A Sanchez, Terrence Bates, Charles Brenneman, A Oberholster, Sahap Kaan Kurtural
Plant water stress affects grape (Vitis vinifera L. cv. Cabernet Sauvignon) berry composition and is variable in space due to variations in the physical environment at the growing site. We monitored the natural variability of grapevine water stress by stem water potential (ψstem) and leaf gas exchange in an equi-distant grid in a commercial vineyard. Spatial differences were measured and related to topographical variation by modeling. Geospatial analysis and clustering allowed to differentiate the vineyard block into two distinct zones having severe and moderate water stress where it varied by 0...
June 12, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28600204/antioxidant-antimicrobial-cell-viability-and-enzymatic-inhibitory-of-antioxidant-polymers-as-biological-macromolecules
#16
REVIEW
Hadi Hashemi Gahruie, Mehrdad Niakousari
Polymeric antioxidants such as Catechinaldehyde Polycondensates, Catechin-acelaldehydepolycondensates, Flavonoid-grafted chitosan fibers, Ferulate hydrogel, Dextran ferulate hydrogel, Starch-quercetin conjugate, Gallic acid- and Caffeic acid-functionalized chitosan, Gallic acid - chitosan conjugate, Poly(rutin), Gallic acid grafted chitosan, Dextran-Catechin Conjugate belong to biological macromolecules. These kinds of compounds have stronger antioxidant potential and pharmacokinetic activities, as compared to similar low molecular weight preservatives...
June 6, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28597441/accumulation-of-catechins-and-expression-of-catechin-synthetic-genes-in-camellia-sinensis-at-different-developmental-stages
#17
Li-Qun Zhang, Kang Wei, Hao Cheng, Li-Yuan Wang, Cheng-Cai Zhang
BACKGROUND: Catechins are the main polyphenol compounds in tea (Camellia sinensis). To understand the relationship between gene expression and product accumulation, the levels of catechins and relative expressions of key genes in tea leaves of different developmental stages were analyzed. RESULTS: The amounts of catechins differed significantly in leaves of different stages, except for gallocatechin gallate. Close correlations between the expression of synthesis genes and the accumulation of catechins were identified...
December 2016: Botanical Studies (Taipei, Taiwan)
https://www.readbyqxmd.com/read/28596773/molecular-link-between-leaf-coloration-and-gene-expression-of-flavonoid-and-carotenoid-biosynthesis-in-camellia-sinensis-cultivar-huangjinya
#18
Lubin Song, Qingping Ma, Zhongwei Zou, Kang Sun, Yuantao Yao, Jihan Tao, Najeeb A Kaleri, Xinghui Li
'Huangjinya' is an excellent albino tea germplasm cultivated in China because of its bright color and high amino acid content. It is light sensitive, with yellow leaves under intense light while green leaves under weak light. As well, the flavonoid and carotenoid levels increased after moderate shading treatment. However, the mechanism underlying this interesting phenomenon remains unclear. In this study, the transcriptome of 'Huangjinya' plants exposed to sunlight and shade were analyzed by high-throughput sequencing followed by de novo assembly...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28595721/study-of-antioxidant-effects-on-malignant-glioma-cells-by-constructing-a-tumor-microvascular-structure-on-microchip
#19
Hanyang Liu, Mingsha Jie, Ziyi He, Hai-Fang Li, Jin-Ming Lin
In this work, a three-dimensional tumor-microvascular structure was simulated on a microfluidic chip for study of antioxidants effects on malignant glioma cells in vitro. The 3D hydrogel containing lumen was constructed to co-culture endothelial cells and glioma cells to mimic tumor microvascular environment. Macroporous gelatin transglutaminase (TG) hydrogel was prepared with biological and mechanical properties suitable for cells culture and nutrient refresh. To reform a vessel structure, U87 cells were dispersed in the TG-gelatin hydrogel and HUVEC cells were seeded in the lumen of hydrogel...
July 25, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28588492/cytotoxic-and-enzyme-inhibitory-potential-of-two-potentilla-species-p-speciosa-l-and-p-reptans-willd-and-their-chemical-composition
#20
Sengul Uysal, Gokhan Zengin, Marcello Locatelli, Mir B Bahadori, Andrei Mocan, Giuseppe Bellagamba, Elisa De Luca, Adriano Mollica, Abdurrahman Aktumsek
In this work, the biological and chemical fingerprints of three extracts (ethyl acetate, methanol, and water) from two Potentilla species (Potentilla reptans and P. speciosa) were investigated. Antioxidant, enzyme inhibitory, and cytotoxic activities were performed for the biological fingerprint. For the chemical characterization, total bioactive components, and individual phenolic components were determined using photometric and HPLC methods, respectively. The main identified phenolic compounds in these extracts were rutin and catechin...
2017: Frontiers in Pharmacology
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