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Jinming Peng, Kaikai Li, Wei Zhu, Xiangyi Deng, Chunmei Li
An efficient method was established by high-speed counter-current chromatography (HSCCC) for preparation of four phenolic compounds from the depolymerization products of persimmon tannin. Using the two solvent systems of n-hexane/ethyl acetate/water (3:17:20, v/v/v) and ethyl acetate/methanol/water (50:1:50, v/v/v), the preparative isolation was successfully performed by a two-step separation. The yields of one run (150mg crude sample) for gallic acid, methyl gallate, and epigallocatechin-3-gallate-(4β→8, 2β→O→7)-epigallocatechin-3-gallate dimer (A-type EGCG dimer) were 4...
November 7, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Gina Borges, Javier I Ottaviani, Justin J J van der Hooft, Hagen Schroeter, Alan Crozier
This paper reviews pioneering human studies, their limitations and recent investigations on the absorption, metabolism, distribution and excretion (aka bioavailability) of (-)-epicatechin. Progress has been made possible by improvements in mass spectrometric detection when coupled to high performance liquid chromatography and through the increasing availability of authentic reference compounds of in vivo metabolites of (-)-epicatechin. Studies have shown that [2-(14)C](-)-epicatechin is absorbed in the small intestine with the 12 structural-related (-)-epicatechin metabolites (SREMs), mainly in the form of (-)-epicatechin-3'-O-glucuronide, 3'-O-methyl-(-)-epicatechin-5-sulfate and (-)-epicatechin-3'-sulfate, attaining sub-μmol/L peak plasma concentrations (Cmax) ∼1 h after ingestion...
November 7, 2017: Molecular Aspects of Medicine
Pilar Ortiz-Vilchis, Miguel Ortiz-Flores, Marcela Pacheco, Israel Ramirez-Sanchez, Aldo Moreno-Ulloa, Lourdes Vega, Alicia Ortiz, Francisco Villarreal, Ivan Rubio-Gayosso, Nayelli Najera, Eduardo Meaney, Guillermo Ceballos
The production of nitric oxide (NO) by nitric oxide synthases (NOS) depends on the bioavailability of L-arginine as NOS competes with arginase for this common substrate. As arginase activity increases, less NO is produced and adverse cardiovascular consequences can emerge. (-)-Epicatechin (EPI), the most abundant flavonoid in cacao, has been reported to stimulate endothelial and neuronal NOS expression and function leading to enhanced vascular function and cardioprotective effects. However, little is known about the effects of EPI on myocardial arginase activity...
November 7, 2017: European Journal of Pharmacology
Bo Yuan, Mei Lu, Kent M Eskridge, Loren D Isom, Milford A Hanna
Hazelnut shells are the major byproduct of the hazelnut industry. The objectives of this study were to optimize the conditions for extracting phenolics and to identify and quantify the phenolics in hazelnut shells. Preliminary optimization showed that a high recovery of phenolics could be achieved with shell particle size less than 0.5mm when extracted with acetone at 50°C. Response surface experiments showed that a 10g/l liquid to solid ratio, 58% acetone, and 12h extraction time yielded the highest amount of phenolics...
April 1, 2018: Food Chemistry
Midori Natsume
BACKGROUND: Polyphenols widely distributed in plants, fruits and vegetables have received considerable attention on account of their physiological functions, including their antioxidant and anti-inflammatory properties. Some antioxidant components of cacao liquor prepared from fermented and roasted cacao beans, which is a major ingredient of cocoa and chocolate products, have been characterized as flavan-3-ols and procyanidin oligomers Methods: This review focuses on a specific group of (-)-epicatechins and their oligomers, the procyanidins, in cacao products...
November 8, 2017: Current Pharmaceutical Design
Catherine Girard, Tania Charette, Maxime Leclerc, B Jesse Shapiro, Marc Amyot
Fish consumption is a major pathway for mercury exposure in humans. Current guidelines and risk assessments assume that 100% of methylmercury (MeHg) in fish is absorbed by the human body after ingestion. However, a growing body of literature suggests that this absorption rate may be overestimated. We used an in vitro digestion method to measure MeHg bioaccessibility in commercially-purchased fish, and investigated the effects of dietary practices on MeHg bioaccessibility. Cooking had the greatest effect, decreasing bioaccessibility on average to 12...
October 30, 2017: Science of the Total Environment
Qing Wang, Zhi-Wei Lu, Yue-Hong Liu, Ming-Ling Wang, Shuang Fu, Qing-Qing Zhang, Hui-Zhen Zhao, Zhi-Xin Zhang, Zi-Ye Xie, Zheng-Hai Huang, Hong-Hong Yu, Wen-Juan Zhou, Xiao-Yan Gao
Diagnostic ions filter method was used to rapidly detect and identify the phenolic compounds in Rheum palmatum based on ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MSE). The representative authentic standards of phenolic compounds, including gallic acid, (+)-catechin, (-)-epicatechin, (-)-epicatechin-3-O-gallate and procyanidin B2, were subjected to analysis by UPLC-Q-TOF/MSE system with negative ion mode. Fragmentation patterns of each standard were summarized based on assigned fragment ions...
May 2017: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
Maria Saarenhovi, Pia Salo, Mika Scheinin, Jussi Lehto, Zsófia Lovró, Kirsti Tiihonen, Markus J Lehtinen, Jouni Junnila, Oliver Hasselwander, Anneli Tarpila, Olli T Raitakari
BACKGROUND: The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD). METHODS: This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg)...
October 27, 2017: Nutrition Journal
Elahe Esmaeelpanah, Bibi Marjan Razavi, Faezeh Vahdati Hasani, Hossein Hosseinzadeh
The neurotoxicity of acrylamide (ACR) monomer occurs through different mechanisms such as oxidative stress. Epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) are green tea catechins which are known as powerful antioxidants. In this study, we examined the possible protective effects of ECG and EGCG on ACR neurotoxicity in both in-vitro and in-vivo models. PC12 cells were exposed to different concentrations of ECG and EGCG. After 24 and 48 hours, ACR was added to the cells (IC50 = 4.85 mM) and cell viability was measured through MTT assay after 24 hours...
October 26, 2017: Drug and Chemical Toxicology
Chhana Ullah, Sybille B Unsicker, Christin Fellenberg, C Peter Constabel, Axel Schmidt, Jonathan Gershenzon, Almuth Hammerbacher
Phenolic secondary metabolites are often thought to protect plants against attack by microbes but their role in defense against pathogen infection in woody plants has not been comprehensively investigated. We studied the biosynthesis, occurrence and anti-fungal activity of flavan-3-ols in black poplar (Populus nigra L.), which include both monomers, such as catechin, and oligomers known as proanthocyanidins (PAs). We identified and biochemically characterized three leucoanthocyanidin reductases (LAR) and two anthocyanidin reductases (ANR) from P...
October 25, 2017: Plant Physiology
Stefan Wiesneth, Gregor Aas, Jörg Heilmann, Guido Jürgenliemk
Flavonoids, proanthocyanidins (PAs) and salicylic alcohol derivatives are the main groups of ingredients in Salix needed as defensive tools and signal molecules, but have also pharmaceutical importance. The present study investigated total PA content, complete PA pattern, the oligomeric/total PAs quotient and the contents of catechin and epicatechin during one growing-season for the leaves and this year's sprouts in ten willows (Salix pentandra L. ♂, S. alba L. ♂, S. fragilis L. ♀, S. caprea L. ♂ & ♀, S...
October 20, 2017: Phytochemistry
Meng Li, Yu Chong, Peter P Fu, Qingsu Xia, Timothy R Croley, Y Martin Lo, Jun-Jie Yin
Although nanosized ingredients, including TiO2 nanoparticles (NPs), can be found in a wide range of consumer products, little is known about the effects these particles have on other active compounds in product matrices. These NPs can interact with reactive oxygen species (ROS), potentially disrupting or canceling the benefits expected from antioxidants. We used electron spin resonance spectrometry to assess changes in the antioxidant capacities of six dietary antioxidants (ascorbic acid, α-tocopherol, glutathione, cysteine, epicatechin, and epicatechin gallate) during exposure to P25 TiO2 and/or simulated sunlight...
November 7, 2017: Journal of Agricultural and Food Chemistry
Mirtha Navarro, Ileana Moreira, Elizabeth Arnaez, Silvia Quesada, Gabriela Azofeifa, Diego Alvarado, Maria J Monagas
The phenolic composition of aerial parts from Petiveria alliaceae L., Phyllanthus niruri L. and Senna reticulata Willd., species commonly used in Costa Rica as traditional medicines, was studied using UPLC-ESI-TQ-MS on enriched-phenolic extracts. Comparatively, higher values of total phenolic content (TPC), as measured by the Folin-Ciocalteau method, were observed for P. niruri extracts (328.8 gallic acid equivalents/g) than for S. reticulata (79.30 gallic acid equivalents/g) whereas P. alliaceae extract showed the lowest value (13...
October 19, 2017: Plants (Basel, Switzerland)
A P L Sabino, L M S Eustáquio, A C F Miranda, C Biojone, T N Mariosa, Cibele Marli Cação Paiva Gouvêa
We evaluated the chemical composition, antioxidant activity, and antitumor potential of a fraction that was isolated from Stryphnodendron adstringens (barbatimão) leaf aqueous extract. Fraction is composed by gallic acid, procyanidin dimer B1, and (-)-epicatechin-3-O-gallate and it exhibits antioxidant and cytotoxic activities. Fraction was cytotoxic against two human breast cancer cell lines, ER (+) and MCF-7 and the triple-negative, MDA-MB-435. The sulforhodamine B assay showed that, as compared to normal control cells, the fraction significantly (P < 0...
October 17, 2017: Applied Biochemistry and Biotechnology
Yunru Peng, Qilu Meng, Jie Zhou, Bo Chen, Junjun Xi, Piaopiao Long, Liang Zhang, Ruyan Hou
Tea polyphenols (TP) were emulsified with corn oil and polysorbate 80 by high-pressure homogenization. The oil in water (O/W) TP nanoemulsion had droplet sizes of 99.42±1.25nm after preparation. The TP nanoemulsion was stable during storage at 4, 25 or 40°C for 20days. An in vitro simulated digestion assay showed that the bioaccessibility of (-)-epigallocatechin gallate (EGCG) was increased in the nanoemulsion compared to that in aqueous solution, but that the bioaccessibilities of (-)-epigallocatechin (EGC), (-)-epicatechin (EC) and (-)-gallocatechin gallate (GCG) were greatly decreased...
March 1, 2018: Food Chemistry
Melek Altındağ, Meltem Türkyılmaz, Mehmet Özkan
BACKGROUND: Changes in polyphenols have important effect on quality (especially color) and health benefits of dried apricots. SO2 concentration, storage and the activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were the factors which had significant effects on polyphenols. Polyphenol profile and activities of PPO and PAL in sulfured dried apricots (SDAs, 0, 451, 832, 2112 and 3241 mg SO2 /kg) were monitored during storage at 4, 20 and 30 °C for 379 days for the first time...
October 12, 2017: Journal of the Science of Food and Agriculture
Omar A Aldulaimi
The emergence and rapid development of seriously drug-resistant pathogens have created the greatest danger to public health and made the treatment of infectious diseases ineffective; to control the antibiotic-resistant microbes, the discovery of new effective antibacterials with new mechanisms of action against bacteria remains an urgent task to control the bacterial resistance. The paucity of infections in wild plants supports the role of innate defense system of plants. Many researchers nominate the natural extracts to act against bacterial resistance mechanisms, and the majority of them have now been focused on the combination of plant extracts and antibiotics to define the availability of resistance modification agents...
July 2017: Pharmacognosy Reviews
Sumit Mukherjee, Priya Ranjan Debata, Rahman Hussaini, Kaushiki Chatterjee, Juliet N E Baidoo, Samay Sampat, Anita Szerszen, Joseph P Navarra, Jimmie Fata, Elena Severinova, Probal Banerjee, Mario R Castellanos
Curcumin (from curry) (C) is highly potent against cervical cancer cells (CCC), but poor bioavailability has limited its clinical use. Similar natural polyphenols resveratrol (from grapes) (R), and epicatechin gallate (from green tea) (E) also display activity against CCC. By treating CCC (HeLa) with C, E, or R, or combinations of these compounds, we computed combination indices and observed a strong synergism among C, E, and R at the unique molar ratio 4:1:12.5. This combination, named as TriCurin, rapidly down regulated HPV18 E6 and NF-kB expression while concomitantly inducing the tumor suppressor protein p53 in HeLa cells...
September 22, 2017: Oncotarget
Jang Hoon Kim, Hyo Young Kim, Seo Young Yang, Jin-Baek Kim, Chang Hyun Jin, Young Ho Kim
(-)-Epicatechin-3,5-O-digallate (ECDG) from Orostachys japonicus A. Berger was examined for inhibitory activity on α-glucosidase. The results showed that the IC50 value was achieved with nanomolar concentrations. Through the enzyme kinetic analysis, ECDG was shown to act as a competitive inhibitor of α-glucosidase by binding to the receptor active site. Fluorescence-quenching measurements showed that ECDG and the enzyme may have a one-to-one reaction with low quenching (Ksv) and binding constants. A molecular docking study was performed to evaluate the receptor-ligand complex...
September 25, 2017: International Journal of Biological Macromolecules
Michalina Grzesik, Katarzyna Naparło, Grzegorz Bartosz, Izabela Sadowska-Bartosz
Antioxidant properties of five catechins and five other flavonoids were compared with several other natural and synthetic compounds and related to glutathione and ascorbate as key endogenous antioxidants in several in vitro tests and assays involving erythrocytes. Catechins showed the highest ABTS-scavenging capacity, the highest stoichiometry of Fe(3+) reduction in the FRAP assay and belonged to the most efficient compounds in protection against SIN-1 induced oxidation of dihydrorhodamine 123, AAPH-induced fluorescein bleaching and hypochlorite-induced fluorescein bleaching...
February 15, 2018: Food Chemistry
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