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Hplc analysis of tea

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https://www.readbyqxmd.com/read/28071811/extraction-of-epigallocatechin-gallate-and-epicatechin-gallate-from-tea-leaves-using-%C3%AE-cyclodextrin
#1
Lu Cui, Yuxuan Liu, Ting Liu, Yahong Yuan, Tianli Yue, Rui Cai, Zhouli Wang
Use of organic solvents to extract phenolic compounds from plants may result in environmental pollution and cause health problems in persons. Replacing organic extraction solvents by green extracting agents without affecting the extraction yield is one of the most pressing problems to be solved. The aim of this study is to evaluate the capacity of β-cyclodextrin (β-CD) to recover phenolic compounds from tea leaves. The extract obtained using the ethanol/water mixture presented the highest total phenolic content, followed by those obtained using β-CD solution and water...
January 10, 2017: Journal of Food Science
https://www.readbyqxmd.com/read/28035976/meadowsweet-teas-as-new-functional-beverages-comparative-analysis-of-nutrients-phytochemicals-and-biological-effects-of-four-filipendula-species
#2
Daniil N Olennikov, Nina I Kashchenko, Nadezhda K Chirikova
In recent years, the increased popularity of functional beverages such as herbal teas and decoctions has led to the search for new sources of raw materials that provide appropriate taste and functionality to consumers. The objective of this study was to investigate the nutritional, phytochemical profiles and bioactivities of possible functional beverages produced from F. ulmaria and its alternative substitutes (F. camtschatica, F. denudata, F. stepposa). The investigated decoctions were analyzed regarding their macronutrient, carbohydrate, organic acid, amino acid and mineral composition...
December 26, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28035158/screening-and-purification-of-catechins-from-underutilized-tea-plant-parts-and-their-bioactivity-studies
#3
Ajay Rana, Eshita Sharma, Kiran Rawat, Ranjana Sharma, Sarika Verma, Yogendra Padwad, Ashu Gulati
Comparative investigation of major phytoconstituents was performed from various parts of tea plant viz. apical bud, subtending 1st-5th leaf, stem, coarse leaves, flowers, fruits and roots. From the results of comparative RP-HPLC-DAD analysis it was found that underutilized tea parts especially coarse leaves, flowers and fruits contains abundant amount of phenolics (17.5%) and catechins (4-5%). From these underutilized tea plant parts the catechins were extracted and purified and then screened for their anticancer, immunomodulatory effect and antimicrobial activity against food borne pathogens...
November 2016: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/27921291/evaluation-of-capillary-electrophoresis-for-the-analysis-of-rooibos-and-honeybush-tea-phenolics
#4
William J Arries, Andreas G J Tredoux, Dalene de Beer, Elizabeth Joubert, André de Villiers
Rooibos and honeybush are popular herbal teas produced from the shrubs of Aspalathus linearis and Cyclopia spp., respectively, which are indigenous to South Africa. Both herbal teas are rich in polyphenols and their consumption is associated with several health benefits, partly ascribed to their phenolic constituents. Quantification of phenolics in extracts and teas for quality control and research purposes is generally performed using HPLC, although dedicated and often species-specific methods are required...
December 6, 2016: Electrophoresis
https://www.readbyqxmd.com/read/27818668/an-approach-based-on-hplc-fingerprint-and-chemometrics-to-quality-consistency-evaluation-of-matricaria-chamomilla-l-commercial-samples
#5
Agnieszka Viapiana, Wiktoria Struck-Lewicka, Pawel Konieczynski, Marek Wesolowski, Roman Kaliszan
Chamomile has been used as an herbal medication since ancient times and is still popular because it contains various bioactive phytochemicals that could provide therapeutic effects. In this study, a simple and reliable HPLC method was developed to evaluate the quality consistency of nineteen chamomile samples through establishing a chromatographic fingerprint, quantification of phenolic compounds and determination of antioxidant activity. For fingerprint analysis, 12 peaks were selected as the common peaks to evaluate the similarities of commercial samples of chamomile obtained from different manufacturers...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27765257/composition-distribution-and-risk-of-total-fluorine-extractable-organofluorine-and-perfluorinated-compounds-in-chinese-teas
#6
Ruobing Zhang, Hong Zhang, Qingwu Chen, Ji Luo, Zhifang Chai, Jincan Shen
To explore the residual characteristics of fluorine and perfluorinated compounds (PFCs) in tea, the total fluorine (TF), extractable organofluorine (EOF) and PFCs in 19 Chinese commercial teas of five categories were measured using cyclic neutron activation analysis combined with HPLC-MS/MS. The results showed that fluorine mainly existed as inorganic fluorine in teas, and identified fluorine (∑PFCs quantified as F) only accounted for 0.023-0.41% of EOF, indicating that most EOF in tea were still unknown...
March 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/27697574/combination-of-hplc-ms-and-qams-as-a-new-analytical-approach-for-determination-of-saponins-in-ginseng-containing-products
#7
Andrey Stavrianidi, Elena Stekolshchikova, Anna Porotova, Igor Rodin, Oleg Shpigun
Conventional liquid chromatographic methods coupled with ultraviolet detection with low-wavelength range are lacking selectivity and sensitivity to determine both polar and less polar ginsenosides. Also the lack of standard substances for such quality control methods is leading to development of the approaches using single standard for quantitative analysis of multi-component system (QAMS). The objective of present study was to establish and compare for the first time liquid chromatography-ultraviolet detection and liquid chromatography-mass spectrometry QAMS methods for the simultaneous determination of protopanaxatriol-type and protopanaxadiol-type ginsenosides in a variety of ginseng products...
January 5, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27693951/quality-assessment-of-marketed-chamomile-tea-products-by-a-validated-hptlc-method-combined-with-multivariate-analysis
#8
Etil Guzelmeric, Petar Ristivojević, Irena Vovk, Dušanka Milojković-Opsenica, Erdem Yesilada
Chamomile tea composed of dried flower heads of Matricaria recutita L. (Asteraceae) is one of the most popular single ingredient herbal teas. Tea industries, spice shops or public bazaars are mostly supplied chamomile as a raw material via cultivation or through nature-picking. However, one of the drawbacks of nature-picking is adulteration. This could be either due to false authentication of the plant materials by ingenuous pickers or intentional/unintentional substitution with other flowers resembling to chamomile in appearance during harvesting...
January 5, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27681250/in-vitro-%C3%AE-glucosidase-inhibitory-activity-of-isolated-fractions-from-water-extract-of-qingzhuan-dark-tea
#9
Shuyuan Liu, Zhi Yu, Hongkai Zhu, Wei Zhang, Yuqiong Chen
BACKGROUND: Natural products have being used as potential inhibitors against carbohydrate-hydrolyzing enzymes to treat diabetes mellitus. Chinese dark tea has various interesting bioactivities. In this study, the active compounds from Qingzhuan dark tea were separated and their anti-diabetic activity was examined using an in vitro enzymatic model. METHODS: The chloroform, ethyl acetate, n-butanol, sediment and residual aqua fractions of a Chinese dark tea (Qingzhuan tea) were prepared by successively isolating the water extract with different solvents and their in vitro inhibitory activities against α-glucosidase were assessed...
September 29, 2016: BMC Complementary and Alternative Medicine
https://www.readbyqxmd.com/read/27633949/analysis-of-theanine-in-tea-camellia-sinensis-dietary-ingredients-and-supplements-by-high-performance-liquid-chromatography-with-postcolumn-derivatization-single-laboratory-validation-first-action-2016-10
#10
Maria Ofitserova, Sareeta Nerkar
An HPLC method with postcolumn derivatization was developed and validated for the determination of theanine content in tea dietary ingredients and supplements. A variety of common commercially available supplement forms such as powders, liquid tinctures, tablets, softgels, and gelcaps, as well as three National Institute of Standards and Technology Camellia sinensis Standard Reference Materials were investigated in the study. A simple extraction procedure using citrate buffer at pH 2.2 allowed for the analysis of theanine without additional cleanup or concentration steps, even at low ppm levels...
September 15, 2016: Journal of AOAC International
https://www.readbyqxmd.com/read/27596421/a-comparative-analysis-of-chemical-compositions-in-camellia-sinensis-var-puanensis-kurihara-a-novel-chinese-tea-by-hplc-and-uflc-q-tof-ms-ms
#11
COMPARATIVE STUDY
Yi-Fang Li, Shu-Hua Ouyang, Yi-Qun Chang, Ting-Mei Wang, Wei-Xi Li, Hai-Yan Tian, Hong Cao, Hiroshi Kurihara, Rong-Rong He
Camellia sinensis var. puanensis Kurihara (Puan tea) is a kind of ancient tea plant newly found in Jiangxipo and the surrounding areas of Puan County (Guizhou, China). People there always believe that drinking Puan tea is beneficial to the promotion of health and prevention of diseases. However, detailed information on its compositions has not been reported. Therefore, in this study, the varieties and contents of purine alkaloids and polyphenols in Puan tea were identified and determined by HPLC and UFLC-Q-TOF-MS/MS...
February 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/27589031/simultaneous-determination-of-eight-catechins-and-four-theaflavins-in-green-black-and-oolong-tea-using-new-hplc-ms-ms-method
#12
Wuqun Tao, Zhiguang Zhou, Bin Zhao, Tongyu Wei
A simple, rapid and accurate analytical method was developed for the analysis of eight tea catechins and four theaflavins simultaneously in three types of tea (green, black and oolong tea), using ultra high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HPLC-MS-MS) in multiple-reaction monitoring (MRM) mode. This method using HPLC-MS-MS in positive mode was performed on a CAPCELL PAK C18 MGIII (2.0mm×100mm, 3μm) column (Shiseido) with the mobile phase consisting of 0...
November 30, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27570151/fingerprint-analysis-and-quality-consistency-evaluation-of-flavonoid-compounds-for-fermented-guava-leaf-by-combining-high-performance-liquid-chromatography-time-of-flight-electrospray-ionization-mass-spectrometry-and-chemometric-methods
#13
Lu Wang, Xiaofei Tian, Wenhao Wei, Gong Chen, Zhenqiang Wu
Guava leaves are used in traditional herbal teas as antidiabetic therapies. Flavonoids are the main active of Guava leaves and have many physiological functions. However, the flavonoid compositions and activities of Guava leaves could change due to microbial fermentation. A high-performance liquid chromatography time-of-flight electrospray ionization mass spectrometry method was applied to identify the varieties of the flavonoids in Guava leaves before and after fermentation. High-performance liquid chromatography, hierarchical cluster analysis and principal component analysis were used to quantitatively determine the changes in flavonoid compositions and evaluate the consistency and quality of Guava leaves...
October 2016: Journal of Separation Science
https://www.readbyqxmd.com/read/27374326/a-novel-functional-full-fat-hard-cheese-containing-liposomal-nanoencapsulated-green-tea-catechins-manufacture-and-recovery-following-simulated-digestion
#14
Ali Rashidinejad, E John Birch, David W Everett
(+)-Catechin or green tea extract were encapsulated in soy lecithin nanoliposomes and incorporated into a full-fat cheese, then ripened at 8 °C for 90 days. Cheese samples were subjected to simulated gastrointestinal digestion to measure total phenolic content (TPC) and antioxidant activity of the cheese digesta, and to determine the catechin recovery after digestion by high performance liquid chromatography (HPLC). Addition of catechin or green tea extract significantly (P ≤ 0.05) increased TPC and antioxidant activity (measured by ferric reducing antioxidant power and oxygen radical absorbance capacity) of the full-fat cheese without affecting pH or proximate composition...
July 13, 2016: Food & Function
https://www.readbyqxmd.com/read/27283097/development-of-a-high-performance-liquid-chromatography-tandem-mass-spectrometry-based-analysis-for-the-simultaneous-quantification-of-various-alternaria-toxins-in-wine-vegetable-juices-and-fruit-juices
#15
Theresa Zwickel, Horst Klaffke, Keith Richards, Michael Rychlik
An analytical method based on high performance liquid chromatography (HPLC) and tandem mass spectrometry (MS/MS) detection for the simultaneous quantification of 12 Alternaria toxins in wine, vegetable juices and fruit juices was developed. Excellent chromatographic performance was demonstrated for tenuazonic acid (TeA) in a multi-analyte method. This comprehensive study is also the first to report the determination of TeA, alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and altenuene (ALT), altertoxin I (ATX-I), altertoxin II (ATX-II), altenuisol (ATL), iso-altenuene (isoALT), altenuic acid III (AA-III) and the AAL toxins TB1 und TB2 in samples from the German market...
July 15, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27086034/functional-testing-of-topical-skin-formulations-using-an-optimised-ex-vivo-skin-organ-culture-model
#16
G P Sidgwick, D McGeorge, A Bayat
A number of equivalent-skin models are available for investigation of the ex vivo effect of topical application of drugs and cosmaceuticals onto skin, however many have their drawbacks. With the March 2013 ban on animal models for cosmetic testing of products or ingredients for sale in the EU, their utility for testing toxicity and effect on skin becomes more relevant. The aim of this study was to demonstrate proof of principle that altered expression of key gene and protein markers could be quantified in an optimised whole tissue biopsy culture model...
July 2016: Archives of Dermatological Research
https://www.readbyqxmd.com/read/27066035/transcriptomic-analysis-reveals-the-molecular-mechanisms-of-drought-stress-induced-decreases-in-camellia-sinensis-leaf-quality
#17
Weidong Wang, Huahong Xin, Mingle Wang, Qingping Ma, Le Wang, Najeeb A Kaleri, Yuhua Wang, Xinghui Li
The tea plant [Camellia sinensis (L.) O. Kuntze] is an important commercial crop rich in bioactive ingredients, especially catechins, caffeine, theanine and other free amino acids, which the quality of tea leaves depends on. Drought is the most important environmental stress affecting the yield and quality of this plant. In this study, the effects of drought stress on the phenotype, physiological characteristics and major bioactive ingredients accumulation of C. sinensis leaves were examined, and the results indicated that drought stress resulted in dehydration and wilt of the leaves, and significant decrease in the total polyphenols and free amino acids and increase in the total flavonoids...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27019564/theanine-and-caffeine-content-of-infusions-prepared-from-commercial-tea-samples
#18
Klára Boros, Nikoletta Jedlinszki, Dezső Csupor
BACKGROUND: Caffeine and L-theanine are pharmacologically important constituents of tea, especially due to their effects on the central nervous system. The effects of these two compounds are opposite: While caffeine is a well-known stimulant, theanine has a relaxing effect. Tea processing may influence the caffeine and theanine content of tea leaves. OBJECTIVE: The aim of our work was to quantify these constituents from a set of commercial products to reveal the possible correlations of caffeine and theanine content and processing methods...
January 2016: Pharmacognosy Magazine
https://www.readbyqxmd.com/read/26947163/screening-for-total-ergot-alkaloids-in-rye-flour-by-planar-solid-phase-extraction-fluorescence-detection-and-mass-spectrometry
#19
Claudia Oellig, Tina Melde
The analysis of ergot alkaloids is generally performed by high-performance liquid chromatography (HPLC) coupled to fluorescence detection (FLD) or mass selective detection. As for monitoring only the sum of ergot alkaloids is relevant, a fast and easy screening method for the determination of the total alkaloid content was developed using planar solid phase extraction (pSPE). Applying pSPE, recently introduced for pesticide residue analysis in fruits and vegetables (Oellig and Schwack, 2011) and tea (Oellig and Schwack, 2012), all ergot alkaloids are concentrated in a target zone followed by detection as the sum...
April 8, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/26932862/-comparison-and-bias-estimation-of-three-methods-in-determination-of-glycated-hemoglobin-a1c
#20
Li Lin, Yonghui Dai, Dongdong Liu, Jingchun Huang, Wen Shi, Chenyu Shang, Wanyi Pan, Feng Qiu, Jianhua Xu
OBJECTIVE: To evaluate the bias of three different methods in determination of glycated hemoglobin A1c (HbA1c). METHODS: According to Clinical and Laboratory Standards Institute (CLSI)EP9-A3 document, 40 serum specimens among linear range were tested by immunoturbidimetry assay (Roche Tina-quant), capillary electrophoresis (Sebia Minicap FP), high performance liquid chromatography system (HPLC, Trinity Biotech Premier Hb 9210™). RESULTS were analyzed by pairwise comparision...
March 1, 2016: Zhonghua Yi Xue za Zhi [Chinese medical journal]
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