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Hplc analysis of tea

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https://www.readbyqxmd.com/read/29705350/mirna-150-5p-associate-with-antihypertensive-effect-of-epigallocatechin-3-gallate-revealed-by-aorta-mirnome-analysis-of-spontaneously-hypertensive-rat
#1
Bing-Jun Qian, Chong-Chong Tian, Xiao-Hong Ling, Li-Li Yu, Feng-Yun Ding, Jiang-Hua Huo, Liu-Cun Zhu, Yao-Lin Wen, Jiang-Hua Zhang, Pu Jing
AIMS: The antihypertensive mechanism (s) of the epigallocatechin-3-gallate (EGCG), a major effective component in green tea, might associate with microRNAs (miRNAs). Here, we aimed to investigate which microRNA in aorta of spontaneously hypertensive rats (SHRs) were modulated by administration of EGCG and its mechanism. MAIN METHODS: The pharmacokinetic behaviors of EGCG and epigallocatechin (EGC) in Sprague-Dawley rats were analyzed by HPLC and DRUG AND STATISTICS software...
April 26, 2018: Life Sciences
https://www.readbyqxmd.com/read/29695058/hplc-ed-analysis-of-phenolic-compounds-in-three-bosnian-crataegus-species
#2
Dušan Čulum, Amira Čopra-Janićijević, Danijela Vidic, Lejla Klepo, Azra Tahirović, Neđad Bašić, Milka Maksimović
The aim of this work was the qualitative and quantitative determination of selected phenolic compounds in three Crataegus species grown in Bosnia. Crataegus plants are consumed for medicinal purposes and as foodstuff in the form of canned fruit, jam, jelly, tea, and wine. Two samples of plant material, dry leaves with flowers, and berries of three Crataegus species— Crataegus rhipidophylla Gand., Crataegus x subsphaericea Gand., and Crataegus x macrocarpa Hegetschw.—were analyzed. Twelve ethanolic extracts were isolated from the selected plant material using Soxhlet and ultrasound extraction, respectively...
April 24, 2018: Foods (Basel, Switzerland)
https://www.readbyqxmd.com/read/29579913/absorption-kinetics-of-vitamin-e-nanoemulsion-and-green-tea-microstructures-by-intestinal-in-situ-single-perfusion-technique-in-rats
#3
Rijuta Ganesh Saratale, Hee-Seok Lee, Yong Eui Koo, Ganesh Dattatraya Saratale, Young Jun Kim, Jee Young Imm, Yooheon Park
The absorption kinetics of food ingredients such as nanoemulsified vitamin E and green tea microstructures were evaluated by the intestinal in situ single perfusion technique. Absorption rate, sub-acute oral toxicity and organ morphology in a rat model were examined. The intestinal in situ single perfusion technique and HPLC analysis were applied to investigate the absorption rate of selected materials by examining time-dependent changes in the serum levels of catechin and dl-α-tocopherol. The acute toxicity test and histopathological evaluation were applied to analyze the safety of microsized green tea and nanosized vitamin E in a rat model...
April 2018: Food Research International
https://www.readbyqxmd.com/read/29364183/antioxidant-and-cytoprotective-effects-of-tibetan-tea-and-its-phenolic-components
#4
Hong Xie, Xican Li, Zhenxing Ren, Weimin Qiu, Jianlan Chen, Qian Jiang, Ban Chen, Dongfeng Chen
Tibetan tea (Kangzhuan) is an essential beverage of the Tibetan people. In this study, a lyophilized aqueous extract of Tibetan tea ( LATT ) was prepared and analyzed by HPLC. The results suggested that there were at least five phenolic components, including gallic acid, and four catechins (i.e., (+)-catechin, (-)-catechin gallate ( CG ), (-)-epicatechin gallate ( ECG ), and (-)-epigallocatechin gallate). Gallic acid, the four catechins, and LATT were then comparatively investigated by four antioxidant assays: ferric reducing antioxidant power, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide radical (PTIO•) scavenging, 1,1-diphenyl-2-picryl-hydrazl radical scavenging, and 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) radical scavenging assays...
January 24, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29345909/metabolomics-study-reveals-enhanced-inhibition-and-metabolic-dysregulation-in-escherichia-coli-induced-by-lactobacillus-acidophilus-fermented-black-tea-extract
#5
Kundi Yang, Matthew L Duley, Jiangjiang Zhu
This study examined the ability of Lactobacillus acidophilus (LA) to ferment black tea extract (BTE) and the enhancement of Escherichia coli cellular uptake of phenolic compounds when these bacteria were incubated with fermented BTE. The inhibitory effects of BTE to E. coli bacteria with and without fermentation were compared. Several intracellular phenolic compounds as well as metabolic profiles of E. coli with and without treatments were also determined using a high-performance liquid chromatography-tandem mass spectrometry-based approach...
February 14, 2018: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/29317677/isolation-and-characterization-of-key-genes-that-promote-flavonoid-accumulation-in-purple-leaf-tea-camellia-sinensis-l
#6
Xiujuan He, Xuecheng Zhao, Liping Gao, Xingxing Shi, Xinlong Dai, Yajun Liu, Tao Xia, Yunsheng Wang
There were several high concentrations of flavonoid components in tea leaves that present health benefits. A novel purple-leaf tea variety, 'Mooma1', was obtained from the natural hybrid population of Longjing 43 variety. The buds and young leaves of 'Mooma1' were displayed in bright red. HPLC and LC-MS analysis showed that anthocyanins and O-Glycosylated flavonols were remarkably accumulated in the leaves of 'Mooma1', while the total amount of catechins in purple-leaf leaves was slightly decreased compared with the control...
January 9, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29290397/antibacterial-potential-of-the-cistus-incanus-l-phenolics-as-studied-with-use-of-thin-layer-chromatography-combined-with-direct-bioautography-and-in-situ-hydrolysis
#7
Ágnes M Móricz, Dariusz Szeremeta, Magdalena Knaś, Ewa Długosz, Péter G Ott, Teresa Kowalska, Mieczysław Sajewicz
The main aim of this study was to detect and identify antibacterial components of fraction I derived from eleven commercial C. incanus herbal teas. Fraction I obtained by a well-established phytochemical protocol of a multi-step extraction was expected to contain flavonoid aglycons alone. Antibacterial profile of fraction I was demonstrated by means of thin-layer chromatography - direct bioautography (TLC-DB) using a Gram positive B. subtilis and a Gram negative A. fischeri strain. Six chromatographic zones of fraction I exhibited a well pronounced antibacterial potential...
January 26, 2018: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29260853/liquid-chromatography-separation-and-mass-spectrometry-detection-of-silver-lipoate-ag-29-la-12-nanoclusters-evidence-of-isomerism-in-the-solution-phase
#8
David M Black, Geronimo Robles, Priscilla Lopez, Stephan B H Bach, Marcos Alvarez, Robert L Whetten
Evidence for the existence of condensed-phase isomers of silver-lipoate clusters, Ag29 (LA)12 , where LA = (R)-α lipoic acid, was obtained by reversed-phase ion-pair liquid chromatography with in-line UV-vis and electrospray ionization (ESI)-MS detection. All components of a raw mixture were separated according to surface chemistry and increasing size via reversed-phase gradient HPLC methods and identified by their corresponding m/z ratio by ESI in the negative ionization mode. Aqueous and methanol mobile-phase mixtures, each containing 400 mM hexafluoroisopropanol (HFIP)-15 mM triethylamine (TEA), were employed to facilitate the interaction between the clusters and stationary phase via formation of ion-pairs...
February 6, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29232949/antioxidative-flavan-3-ol-dimers-from-the-leaves-of-camellia-fangchengensis
#9
Xiu-Hua Meng, Chang Liu, Rong Fan, Li-Fang Zhu, Shi-Xiong Yang, Hong-Tao Zhu, Dong Wang, Chong-Ren Yang, Ying-Jun Zhang
Camellia fangchengensis Liang et Zhong, belonging to the genus Camellia sect. Thea (Theaceae), is an endemic tea species to the south and southwest areas of Guangxi province, People's Republic of China. Known as a wild tea plant, the leaves have been used for producing green tea or black tea by the local people of its growing area. HPLC and LC-MS analysis showed the leaves contain oligomeric catechins as major phenolic components. Further detailed phytochemical study led to the identification of five flavan-3-ol dimers (1-5) including two new ones, fangchengbisflavans A (1) and B (2) from the leaves of C...
January 10, 2018: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/29219744/n-nitrosamines-migrating-from-food-contact-materials-into-food-simulants-analysis-and-quantification-by-means-of-hplc-apci-ms-ms
#10
Friederike Kühne, Oliver Kappenstein, Samira Straβgütl, Florian Weese, Jürgen Weyer, Karla Pfaff, Andreas Luch
It was the aim of the work described here to develop a validated analytical method for the determination of N-nitrosamines in food simulants. Here, we present the validation of a liquid chromatography-atmospheric pressure chemical ionisation-tandem mass spectrometry method for the determination of 13 N-nitrosamines in the food simulants deionised water, 3% acetic acid and 10% ethanol. Method validation encompassed linearity, LOD, LOQ, recovery, precision and stability of the N-nitrosamines. The method was found to be sufficiently rugged and suitable for routine analysis...
January 19, 2018: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/29195939/profiling-and-quantification-of-phenolic-compounds-in-camellia-seed-oils-natural-tea-polyphenols-in-vegetable-oil
#11
Xiaoqin Wang, Qiumei Zeng, María Del Mar Contreras, Lijuan Wang
In Asia, tea seed oils (seed oils from Camellia oleifera, C. chekiangoleosa, and C. sinensis) are used in edible, medicinal, and cosmetic applications. However, these oils differ in their fatty acid contents, and there is little known about their phenolic compounds. Here we analyzed the phenolic compounds of seed oils from three species gathered from 15 regions of China. Twenty-four phenolic compounds were characterized by HPLC-Q-TOF-MS, including benzoic acids (6), cinnamic acids (6), a hydroxyphenylacetic acid, flavanols (4), flavonols (3), flavones (2), and dihydroflavonoids (2)...
December 2017: Food Research International
https://www.readbyqxmd.com/read/29120758/antioxidant-capacity-and-major-polyphenol-composition-of-teas-as-affected-by-geographical-location-plantation-elevation-and-leaf-grade
#12
Chuang Zhang, Claire Li-Chieh Suen, Chao Yang, Siew Young Quek
Tea polyphenols have been a topic of discussion due to their health benefits. Nevertheless, detailed studies on the antioxidant capacity and polyphenol contents of teas in relation to factors including geographical locations, plantation elevations and leaf grades have been limited. In this study, 53 tea samples were analysed to determine the individual and total catechin and theaflavin contents by HPLC and the total antioxidant capacity by Oxygen Radical Absorbance Capacity (ORAC) methods. Results show that the polyphenol (catechins and theaflavins) contents were significantly influenced by plantation location...
April 1, 2018: Food Chemistry
https://www.readbyqxmd.com/read/29100264/microwave-mediated-synthesis-and-analytical-method-development-for-the-estimation-of-novel-1-4-dihydropyridines-in-bulk-by-rp-hplc
#13
Anupreet Kaur, Jaspreet Kaur, Ranju Bansal
The present work describes a rapid and green microwave mediated method for the synthesis and a simple and precise isocratic reverse phase HPLC method for the estimation of the biologically significant dihydropyridines. The conventional synthesis of these dihydropyridines has been previously reported from our lab. The analysis of a standard solution (1 mg/ml) was accomplished on a symmetry (4.6 mm I.D x 250 mm) C-18 column using mobile phase acetonitrile:water:triethylamine (TEA) (70:30:0.1 v/v/v) at a flow rate of 0...
November 3, 2017: Drug Research
https://www.readbyqxmd.com/read/28964516/new-potentially-antihypertensive-peptides-liberated-in-milk-during-fermentation-with-selected-lactic-acid-bacteria-and-kombucha-cultures
#14
Ebrahim Elkhtab, Mohamed El-Alfy, Mohamed Shenana, Abdelaty Mohamed, Ahmed E Yousef
Compounds with the ability to inhibit angiotensin-converting enzyme (ACE) are used medically to treat human hypertension. The presence of such compounds naturally in food is potentially useful for treating the disease state. The goal of this study was to screen lactic acid bacteria, including species commonly used as dairy starter cultures, for the ability to produce new potent ACE-inhibiting peptides during milk fermentation. Strains of Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus delbrueckii ssp...
September 27, 2017: Journal of Dairy Science
https://www.readbyqxmd.com/read/28947204/preparation-of-a-reversed-phase-anion-exchange-mixed-mode-spherical-sorbent-by-pickering-emulsion-polymerization-for-highly-selective-solid-phase-extraction-of-acidic-pharmaceuticals-from-wastewater
#15
Chaonan Huang, Yun Li, Jiajia Yang, Junyu Peng, Jing Jin, Dhanjai, Jincheng Wang, Jiping Chen
The present work represents a simple and effective preparation of a novel mixed-mode anion-exchange (MAX) sorbent based on porous poly[2-(diethylamino)ethyl methacrylate-divinylbenzene] (poly(DEAEMA-DVB)) spherical particles synthesized by one-step Pickering emulsion polymerization. The poly(DEAEMA-DVB) particles were quaternized with 1,4-butanediol diglycidyl ether (BDDE) followed by triethylamine (TEA) via epoxy-amine reaction to offer strong anion exchange properties. The synthesized MAX sorbent was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, nitrogen adsorption-desorption measurements and elemental analysis...
October 27, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28928532/effect-of-interaction-of-epigallocatechin-gallate-and-flavonols-on-color-alteration-of-simulative-green-tea-infusion-after-thermal-treatment
#16
Qianying Dai, Yuanyuan He, Chit-Tang Ho, Jing Wang, Shujuan Wang, Yue Yang, Liping Gao, Tao Xia
Epigallocatechin gallate (EGCG) and flavonols are important phenolic compounds in green tea. These compounds are sensitive to thermal condition and their structural alteration results in making browning the green tea infusion. This study aimed to research the interaction between EGCG and flavonols during thermal infusion. EGCG and flavonols model solutions were prepared based on concentration in green tea infusion, and their colors appearance and attributes were analyzed in 10 h by thermal treatment. Results showed that kaempferol, quercetin, and myricetin accelerated the oxidation of EGCG and made the model solution browning...
August 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28895237/a-comprehensive-characterisation-of-rosemary-tea-obtained-from-rosmarinus-officinalis-l-collected-in-a-sub-humid-area-of-tunisia
#17
Mariem Achour, Raquel Mateos, Maha Ben Fredj, Ali Mtiraoui, Laura Bravo, Saad Saguem
INTRODUCTION: Rosemary (Rosmarinus officinalis L.) is an aromatic plant common in Tunisia and it is widely consumed as a tea in traditional cuisine and in folk medicine to treat various illnesses. Currently, most research efforts have been focused on rosemary essential oil, alcoholic and aqueous extracts, however, little is reported on rosemary infusion composition. OBJECTIVE: To investigate compounds present in rosemary tea obtained from Rosmarinus officinalis L...
January 2018: Phytochemical Analysis: PCA
https://www.readbyqxmd.com/read/28890268/acylhydrazone-bond-dynamic-covalent-polymer-gel-monolithic-column-online-coupling-to-high-performance-liquid-chromatography-for-analysis-of-sulfonamides-and-fluorescent-whitening-agents-in-food
#18
Chengjiang Zhang, Xialin Luo, Tianfu Wei, Yufei Hu, Gongke Li, Zhuomin Zhang
A new dynamic covalent polymer (DCP) gel was well designed and constructed based on imine chemistry. Polycondensation of 4,4'-biphenyldicarboxaldehyde and 1,3,5-benzenetricarbohydrazide via Schiff-base reaction resulted in an acylhydrazone bond gel (AB-gel) DCP. AB-gel DCP had three-dimensional network of interconnected nanoparticles with hierarchically porous structure. AB-gel DCP was successfully fabricated as a monolithic column by an in-situ chemical bonding method for online enrichment and separation purpose with excellent permeability...
October 13, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28879218/identification-of-epigallocatechin-3-o-3-o-methyl-gallate-egcg3-me-and-amino-acid-profiles-in-various-tea-camellia-sinensis-l-cultivars
#19
Hyang-Gi Ji, Yeong-Ran Lee, Min-Seuk Lee, Kyeng Hwan Hwang, Eun-Hee Kim, Jun Seong Park, Young-Shick Hong
This article includes experimental data on the identification of epigallocatechin-3-O-(3-O-methyl)-gallate (EGCG3''Me) by 2-dimensional (2D) proton ((1)H) NMR analysis and on the information of amino acid and catechin compound profiles by HPLC analysis in leaf extracts of various tea cultivars. These data are related to the research article "Metabolic phenotyping of various tea (Camellia sinensis L.) cultivars and understanding of their intrinsic metabolism" (Ji et al., 2017) [1]. The assignment for EGCG3x''Me by (1)H NMR analysis was also confirmed with spiking experiment of its pure chemical...
October 2017: Data in Brief
https://www.readbyqxmd.com/read/28863898/the-enhanced-inhibition-of-water-extract-of-black-tea-under-baking-treatment-on-%C3%AE-amylase-and-%C3%AE-glucosidase
#20
Da-Peng Tong, Ke-Xue Zhu, Xiao-Na Guo, Wei Peng, Hui-Ming Zhou
This paper studied the inhibition of water extract of natural or baked black tea on the activity of α-amylase and α- glucosidase. Baking treatment was found to be one effective way to enhance the inhibition of black tea on both α-amylase and α- glucosidase, and IC50 of water extract of baked black tea (BBTWE) were 1.213mg/mL and 4.190mg/mL, respectively, while IC50 of water extract of black tea (BTWE) were 1.723mg/mL and 6.056mg/mL, respectively. This study further studied the mechanism of the effect of water extract on α-amylase and α- glucosidase using HPLC, circular dichroism, and synchronous fluorescence...
February 2018: International Journal of Biological Macromolecules
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