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LC/ MS-MS analysis of tea

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https://www.readbyqxmd.com/read/28388787/antidiabetic-activities-of-an-lc-ms-fingerprinted-aqueous-extract-of-fagonia-cretica-l-in-preclinical-models
#1
Imran Nazir, Nisar Ur Rahman, Zunaira Alvi, M Hafizur Rahman, Jandirk Sendker, Tao Zhang, Neil Frankish, Helen Sheridan
Diabetes mellitus is a chronic disease and one of the most important public health challenges facing mankind. Fagonia cretica is a medicinal plant used widely in the Punjab in Pakistan. A recent survey has demonstrated that traditional healers and herbalists frequently use this plant to treat diabetes. In the current study, the traditional medicine was prepared as a tea, and the profile of the main metabolites present in the traditional medicine was analysed via LC/MS/MS. The extract was shown to contain a number of phenolic glycosides including quercetin-3-O-rutinoside, kaempferol-3-O-rutinoside, kaempferol-3-O-glycoside, kaempferol-3(6'-malonylglucoside), isorhamnetin-3-O-rutinoside, and isorhamnetin 3-(6″-malonylglucoside) in addition to two unidentified sulphonated saponins...
April 7, 2017: Planta Medica
https://www.readbyqxmd.com/read/28317742/determination-of-hymexazol-in-26-foods-of-plant-origin-by-modified-quechers-method-and-liquid-chromatography-tandem-mass-spectrometry
#2
Zejun Jiang, Hui Li, Xiaolin Cao, Pengfei Du, Hua Shao, Fen Jin, Maojun Jin, Jing Wang
A rapid and sensitive method based on modified QuEChERS for hymexazol determination in 26 plant-derived foods using liquid chromatography tandem-mass spectrometry (LC-MS/MS) was developed. Variables affecting the separation (LC column, mobile phase additives) and clean-up effects of various dispersive phases, such as PSA, C18, GCB, MWCNTs, PEP-2, Al2O3, Florisil, and PVPP were evaluated. The method was validated using 26 matrices at spiked levels of 0.01 or 0.02, 0.05, 0.1, and 0.5mg/kg (0.05, 0.2, 0.5, and 1...
August 1, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28300023/optimization-and-validation-of-a-residue-analysis-method-for-glyphosate-glufosinate-and-their-metabolites-in-plant-matrixes-by-liquid-chromatography-with-tandem-mass-spectrometry
#3
Dasharath P Oulkar, Sandip Hingmire, Arnab Goon, Manjusha Jadhav, Bharat Ugare, Ahammed Shabeer Thekkumpurath, Kaushik Banerjee
A sensitive and accurate LC with tandem MS (MS/MS)-based method was developed and validated for the analysis of the herbicide glyphosate, its metabolite aminomethylphosphonic acid (AMPA), and glufosinate after derivatization with 9-fluorenylmethyl chloroformate (FMOC-Cl) in various plant matrixes. The method also covers direct analysis of the glufosinate metabolites 3-methylphosphinicopropionic acid (3-MPPA) and N-acetyl-glufosinate (NAG). The homogenized samples were extracted with 0.1% formic acid in water-dichloromethane (50 + 50)...
May 1, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28183283/comparative-proteomics-analysis-of-teleost-intermuscular-bones-and-ribs-provides-insight-into-their-development
#4
Chun-Hong Nie, Shi-Ming Wan, Tea Tomljanovic, Tomislav Treer, Chung-Der Hsiao, Wei-Min Wang, Ze-Xia Gao
BACKGROUND: Intermuscular bones (IBs) and ribs both are a part of skeletal system in teleosts, but with different developing process. The chemical composition of fish IBs and ribs as well as the underlying mechanism about their development have not been investigated. In the present study, histological structures showed that one bone cavity containing osteoclasts were existed in ribs, but not in IBs of Megalobrama amblycephala. We constructed the first proteomics map for fish bones including IBs and ribs, and identified the differentially expressed proteins between IBs and ribs through iTRAQ LC-MS/MS proteomic analysis...
February 10, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28070878/effects-of-caffeic-acid-and-quercetin-on-in-vitro-permeability-metabolism-and-in-vivo-pharmacokinetics-of-melatonin-in-rats-potential-for-herb-drug-interaction
#5
Snehasis Jana, Himanshu Rastogi
BACKGROUND AND OBJECTIVES: Melatonin is a popular dietary supplement and also considered as pharmaceutical product for sleep disorders. Caffeic acid and quercetin are widely distributed in leafy vegetables, fruits, tea extract, and both are used as natural antioxidant. There is an immense concern for health researchers to study the herb/food-drug interactions of melatonin. It is mainly metabolized by CYP1A2 in human so that herbs/foods containing cytochrome P450 (CYP) inhibitors can affect pharmacokinetics of melatonin...
January 9, 2017: European Journal of Drug Metabolism and Pharmacokinetics
https://www.readbyqxmd.com/read/27957687/evaluation-of-an-enzyme-immunoassay-for-the-detection-of-the-mycotoxin-tenuazonic-acid-in-sorghum-grains-and-sorghum-based-infant-food
#6
Madeleine Gross, Stefan Asam, Michael Rychlik
An enzyme-linked immunosorbent assay (ELISA) for the Alternaria mycotoxin tenuazonic acid (TeA) was evaluated by comparative analysis of naturally contaminated sorghum grains and sorghum-based infant food, using a stable isotope dilution LC-MS assay (SIDA; limit of detection (LOD) 1.0 μg/kg) as the reference method. LODs of the ELISA were 30 μg/kg in sorghum grains and 220 μg/kg in sorghum-based infant cereals. With SIDA, 100% of the samples (n = 28) had been positive for TeA in a concentration range of 6-584 μg/kg (mean 113 μg/kg)...
February 2017: Mycotoxin Research
https://www.readbyqxmd.com/read/27725073/high-throughput-analytical-techniques-for-the-determination-of-the-residues-of-653-multiclass-pesticides-and-chemical-pollutants-in-tea-part-vii-a-gc-ms-gc-ms-ms-and-lc-ms-ms-study-of-the-degradation-profiles-of-pesticide-residues-in-green-tea
#7
Qiao-Ying Chang, Guo-Fang Pang, Chun-Lin Fan, Hui Chen, Fang Yang, Jie Li, Bi-Fang Wen
GC-MS, GC-tandem MS (MS/MS), and LC-MS/MS were used to mathematically define the degradation profiles of pesticide residues in two field trials. Nineteen pesticides were studied in the first field trial and 11 in the second. The results of the field trials demonstrated that the degradation profiles of pesticide residues in green tea can be described with power functions to successfully estimate the amount of time, following pesticide application, pesticide residues appearing in tea in concentrations at and/or above the maximum residue limit (MRL) decrease to concentrations below the MRL...
November 1, 2016: Journal of AOAC International
https://www.readbyqxmd.com/read/27619091/golf-ball-assisted-electrospray-ionization-of-mass-spectrometry-for%C3%A2-the%C3%A2-determination-of-trace-amino-acids-in-complex-samples
#8
Yen-Hsien Li, Chung-Yu Chen, Cheng-Hsiung Kuo, Maw-Rong Lee
During the electrospray ionization (ESI) process, ions move through a heated capillary aperture to be detected on arrival at a mass analyzer. However, the ESI process creates an ion plume, which expands into an ion cloud with an area larger than that of the heated capillary aperture, significantly contributing to an ion loss of 50% due to coulombic repulsion. The use of DC and RF fields to focus ions from the ion source into the vacuum chamber has been proposed in the literature, but the improvement of ion transmission efficiency is limited...
September 28, 2016: Analytica Chimica Acta
https://www.readbyqxmd.com/read/27507726/automated-multi-plug-filtration-cleanup-for-liquid-chromatographic-tandem-mass-spectrometric-pesticide-multi-residue-analysis-in-representative-crop-commodities
#9
Yuhong Qin, Jingru Zhang, Yuan Zhang, Fangbing Li, Yongtao Han, Nan Zou, Haowei Xu, Meiyuan Qian, Canping Pan
An automated multi-plug filtration cleanup (m-PFC) method on modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) extracts was developed. The automatic device was aimed to reduce labor-consuming manual operation workload in the cleanup steps. It could control the volume and the speed of pulling and pushing cycles accurately. In this work, m-PFC was based on multi-walled carbon nanotubes (MWCNTs) mixed with other sorbents and anhydrous magnesium sulfate (MgSO4) in a packed tip for analysis of pesticide multi-residues in crop commodities followed by liquid chromatography with tandem mass spectrometric (LC-MS/MS) detection...
September 2, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27211616/optimized-combination-of-dilution-and-refined-quechers-to-overcome-matrix-effects-of-six-types-of-tea-for-determination-eight-neonicotinoid-insecticides-by-ultra-performance-liquid-chromatography-electrospray-tandem-mass-spectrometry
#10
Weiting Jiao, Yu Xiao, Xiaosan Qian, Mengmeng Tong, Yizheng Hu, Ruyan Hou, Rimao Hua
Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) is a primary tool for analysis of low volatility compounds in complex matrices. However, complex matrices, such as different types of tea, complicate analysis through ionization suppression or enhancement. In this study, sample preparation by a refined QuEChERS method combined with a dilution strategy removed almost all matrix effects caused by six types of tea. Tea samples were soaked with water and extracted with acetonitrile, cleaned up with a combination of PVPP (160mg) and GCB (20mg), and dried...
November 1, 2016: Food Chemistry
https://www.readbyqxmd.com/read/27137993/swapdt-a-method-for-short-time-withering-assessment-of-probability-for-drought-tolerance-in-camellia-sinensis-validated-by-targeted-metabolomics
#11
Christopher Nyarukowa, Robert Koech, Theodor Loots, Zeno Apostolides
Climate change is causing droughts affecting crop production on a global scale. Classical breeding and selection strategies for drought-tolerant cultivars will help prevent crop losses. Plant breeders, for all crops, need a simple and reliable method to identify drought-tolerant cultivars, but such a method is missing. Plant metabolism is often disrupted by abiotic stress conditions. To survive drought, plants reconfigure their metabolic pathways. Studies have documented the importance of metabolic regulation, i...
July 1, 2016: Journal of Plant Physiology
https://www.readbyqxmd.com/read/26782294/bioanalytical-lc-ms-study-of-potential-bacterial-transglycosylation-inhibitors
#12
Bart Blanchaert, Ismail Murat Palabiyik, Alper Gökbulut, Ming-Juan Wang, Zhong Dai, Feng Wei, Shuang-Cheng Ma, Erwin Adams, Ann Van Schepdael
Bacterial transglycosylation is an interesting target in antibiotic drug development. An in vitro transglycosylation assay was developed and used to search for possible inhibitors of Staphylococcus aureus Penicillin Binding Protein 2-mediated transglycosylation. Since the substrate, Lipid II, has no UV-chromophore, the assay relies on LC coupled to MS for analysis of the incubation mixtures. Extracts from Thymus sipyleus, Salvia verticillata, Salvia virgata and Oolong tea were tested, as well as epigallocatechin gallate and ursolic acid, which are chemical compounds derived from plants...
August 5, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/26608291/lc-ms-based-metabolomic-investigation-of-chemopreventive-phytochemical-elicited-metabolic-events
#13
Lei Wang, Dan Yao, Chi Chen
Phytochemicals are under intensive investigation for their potential use as chemopreventive agents in blocking or suppressing carcinogenesis. Metabolic interactions between phytochemical and biological system play an important role in determining the efficacy and toxicity of chemopreventive phytochemicals. However, complexities of phytochemical biotransformation and intermediary metabolism pose challenges for studying phytochemical-elicited metabolic events. Metabolomics has become a highly effective technical platform to detect subtle changes in a complex metabolic system...
2016: Methods in Molecular Biology
https://www.readbyqxmd.com/read/26607316/online-screening-of-nitric-oxide-scavengers-in-natural-products-using-high-performance-liquid-chromatography-coupled-with-tandem-diode-array-and-fluorescence-detection
#14
Dapeng Li, Ting Wang, Yujie Guo, Yuanjia Hu, Boyang Yu, Jin Qi
Nitric oxide (NO) is an important cellular signaling molecule with extensive physiological and pathophysiological effects. NO scavengers have the potential to treat inflammation, septic shock and other related diseases, and numerous examples have been chemically synthesized or isolated from natural products. The chemical diversity of natural products, however, means that a huge effort is necessary to efficiently screen and identify bioactive compounds, especially NO scavengers. In this article, we propose an effective analytical method to screen for NO scavengers in three natural products using an online system that couples high performance liquid chromatography with tandem diode array and fluorescence detection (HPLC-DAD-FLD)...
December 18, 2015: Journal of Chromatography. A
https://www.readbyqxmd.com/read/26578210/simultaneous-analysis-of-mono-di-and-tri-ethanolamine-in-cosmetic-products-using-liquid-chromatography-coupled-tandem-mass-spectrometry
#15
Kyong-Oh Shin, Yong-Moon Lee
Alkanolamines such as monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA) are used as wetting agents in shampoos, lotions, creams, and other cosmetics. DEA is widely used to provide lather in shampoos and maintain a favorable consistency in lotions and creams. Although DEA is not harmful, it may react with other ingredients in the cosmetic formula after extended storage periods to form an extremely potent carcinogen called nitrosodiethanolamine (NDEA), which is readily absorbed through the skin and has been linked to the development of stomach, esophagus, liver, and bladder cancers...
January 2016: Archives of Pharmacal Research
https://www.readbyqxmd.com/read/26551209/quantitative-analysis-of-intracellular-nucleoside-triphosphates-and-other-polar-metabolites-using-ion-pair-reversed-phase-liquid-chromatography-coupled-with-tandem-mass-spectrometry
#16
Jianmei Wu, Yingtao Zhang, Richard Wiegand, Jian Wang, Gerold Bepler, Jing Li
Simultaneous, quantitative determination of intracellular nucleoside triphosphates and other polar metabolites using liquid chromatography with electrospray ionization tandem mass spectrometry (LC-MS/MS) represents a bioanalytic challenge because of charged, highly hydrophilic analytes presented at a large concentration range in a complex matrix. In this study, an ion pair LC-MS/MS method using triethylamine (TEA)-hexafluoroisopropanol (HFIP) ion-pair mobile phase was optimized and validated for simultaneous and unambiguous determination of 8 nucleoside triphosphates (including ATP, CTP, GTP, UTP, dATP, dCTP, dGTP, and dTTP) in cellular samples...
December 1, 2015: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/26525263/high-throughput-analytical-techniques-for-the-determination-and-confirmation-of-residues-of-653-multiclass-pesticides-and-chemical-pollutants-in-tea-by-gc-ms-gc-ms-ms-and-lc-ms-ms-collaborative-study-first-action-2014-09
#17
Guo-Fang Pang, Chun-Lin Fan, Yan-Zhong Cao, Fang Yan, Yan Li, Jian Kang, Hui Chen, Qiao-Ying Chang
Thirty laboratories from fom North and South America, Europe, and Asia participated in this AOAC collaborative study (15 from China; five from Germany; two each from Italy and the United States; and one each from the Republic of Korea, Canada, Spain, Japan, Belgium, and India). Participants represented government regulatory, commercial testing, university, research institute, and private laboratories. The single-laboratory validated (SLV) tea method was evaluated in the collaborative study to determine the recovery and reproducibility of the method under multilaboratory conditions...
September 2015: Journal of AOAC International
https://www.readbyqxmd.com/read/26404216/enhanced-bioaccessibility-of-crocetin-sugar-esters-from-saffron-in-infusions-rich-in-natural-phenolic-antioxidants
#18
Stella A Ordoudi, Anastasia Kyriakoudi, Maria Z Tsimidou
The present study aims to examine whether and to what extent the bioaccessibility of the major saffron apocarotenoids, namely crocetin sugar esters (CRTSEs), is affected by the presence of strong water-soluble antioxidants, ingredients of the herbs found in commercial tea blends with saffron. An in vitro digestion model was applied to infusions from these products to investigate the possible changes. All of the studied infusions were rich in total phenols (9.9-22.5 mg caffeic acid equivalents/100 mg dry infusion) and presented strong DPPH radical scavenging activity regardless of the composition of the corresponding herbal blends...
2015: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/26349944/determination-of-the-oxidative-stress-biomarker-urinary-8-hydroxy-2-deoxyguanosine-by-automated-on-line-in-tube-solid-phase-microextraction-coupled-with-liquid-chromatography-tandem-mass-spectrometry
#19
Hiroyuki Kataoka, Keisuke Mizuno, Eri Oda, Akihiro Saito
A simple and sensitive method for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage in human urine, was developed using automated on-line in-tube solid-phase microextraction (SPME) coupled with stable isotope-dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). Creatinine was also analyzed simultaneously to normalize urine volume by the in-tube SPME LC-MS/MS method, and 8-OHdG and creatinine were separated within 3 min using a Zorbax Eclipse XDB-C8 column...
April 15, 2016: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/26299992/development-of-lc-ms-ms-analysis-of-cyclic-dipeptides-and-its-application-to-tea-extract
#20
Kenji Yamamoto, Miki Hayashi, Yuka Murakami, Yoko Araki, Yuuki Otsuka, Takehiro Kashiwagi, Tomoko Shimamura, Hiroyuki Ukeda
2,5-Diketopiperazines (DKPs), also called cyclic dipeptides, have been known to occur in various foods. Recently, DKPs have attracted attentions as bioactive components. There were some reports on analytical methods for DKPs, but the number of analyzed DKPs was only a part of all DKPs and the quantitative performance was not studied in detail. In this study, we selected 31 kinds of DKPs and developed a quantitative and simultaneous analytical method using LC-MS/MS. This method was applied to DKPs determination in Pu-erh tea, post-fermentation tea, and 18 kinds of DKPs were determined at concentration of 0...
2015: Bioscience, Biotechnology, and Biochemistry
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