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https://www.readbyqxmd.com/read/28722219/preparation-and-evaluation-of-tert-leucine-derivative-functionalized-polymeric-monoliths-for-micro-liquid-chromatography
#1
Meng Ruan, Qiqin Wang, Huihui Wu, Yuqiang Wang, Hai Han, Zhengjin Jiang
In the present study, a novel functional monomer N-[1-(α-naphthyl)ethylaminocarbonyl]-D-tert-leucine-[2-(methacryloyloxy)ethyl] amide (NA-D-tert-Leu-MA) was synthesized, and then employed to prepare polymeric monoliths (240 mm × 100 μm I.D.) functionalized with tert-leucine derivative through a single step thermo-initiated co-polymerization approach or a multi-step post-modification approach. The multi-step approach involves the post-modification of a thiol-containing monolith with NA-D-tert-Leu-MA via "thiol-ene" click reaction...
July 19, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28640307/healthy-properties-of-green-and-white-teas-an-update
#2
REVIEW
S Pastoriza, M Mesías, C Cabrera, J A Rufián-Henares
Green tea has been consumed for centuries in Japan, China and Morocco. White tea, which is considered a variety of green tea, is mostly consumed in China and is very appreciated for its flavor. Currently the consumption of both types of tea has been extended to the western countries even as a functional ingredient. A group of polyphenols called catechins stands out among their bioactive components, the most abundant being the (-) epigallocatechin gallate, with high antioxidant power. Teas also contain other phenolic compounds such as gallic, caffeic, chlorogenic or cinnamic acids, quercetin and proanthocyanidols, caffeine, theophylline, l-theanine and minerals such as fluorine, manganese or chromium...
June 22, 2017: Food & Function
https://www.readbyqxmd.com/read/28624333/l-theanine-prevent-quinolinic-acid-induced-motor-deficit-and-striatal-neurotoxicity-reduction-in-oxido-nitrosative-stress-and-restoration-of-striatal-neurotransmitters-level
#3
Sumit Jamwal, Shamsher Singh, Jaskamal Singh Gill, Puneet Kumar
L-theanine has been documented to possess anti-oxidant, anti-inflammatory and neuroprotective potential in various animal models of neurological disorders. The present study was anticipated to investigate the effect of L-theanine against quinolinic acid induced motor deficits, oxido-nitrosative stress, neuro-inflammation and neurotransmitters alteration in rats. Rats were stereotaxically injected QA (200 nmol/2µl saline; intrastriatal); bilaterally on 0day and L-theanine (25 & 50mg/kg; p.o.) was administered for 21 days starting from day 1 of QA injection...
June 14, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28597057/an-l-glutamine-transporter-isoform-for-neurogenesis-facilitated-by-l-theanine
#4
REVIEW
Yukio Yoneda
L-Theanine (=γ-glutamylethylamide) is an amino acid ingredient in green tea with a structural analogy to L-glutamine (L-GLN) rather than L-glutamic acid (L-GLU), with regards to the absence of a free carboxylic acid moiety from the gamma carbon position. L-theanine markedly inhibits [(3)H]L-GLN uptake without affecting [(3)H]L-GLU uptake in cultured neurons and astroglia. In neural progenitor cells with sustained exposure to L-theanine, upregulation of the L-GLN transporter isoform Slc38a1 expression and promotion of both proliferation and neuronal commitment are seen along with marked acceleration of the phosphorylation of mammalian target of rapamycin (mTOR) and relevant downstream proteins...
June 9, 2017: Neurochemical Research
https://www.readbyqxmd.com/read/28585285/the-synergistic-potential-of-various-teas-herbs-and-therapeutic-drugs-in-health-improvement-a-review
#5
REVIEW
F Malongane, L J McGaw, F N Mudau
Tea is one of the most widely consumed non-alcoholic beverages in the world next to water. It is classified as Camellia sinensis and non-Camellia sinensis (herbal teas). The common bioactive compounds found mainly in green teas are flavan-3-ols (catechins) (also called flavanols), proanthocyanidins (tannins) and flavonols. Black tea contains theaflavins and thearubigins and white tea contains L-theanine and gamma-aminobutyric acid (GABA), while herbal teas contain diverse polyphenols. Phytochemicals in tea exhibit anti-microbial, anti-diabetic and anti-cancer activities that are perceived to be helpful in managing chronic diseases linked to lifestyle...
June 6, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28566632/anti-stress-effect-of-green-tea-with-lowered-caffeine-on-humans-a-pilot-study
#6
Keiko Unno, Hiroshi Yamada, Kazuaki Iguchi, Hitoshi Ishida, Yasunori Iwao, Akio Morita, Yoriyuki Nakamura
Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the effect of theanine was blocked by caffeine and gallate-type catechins, which are the main components in tea. We examined the anti-stress effect of green tea with lowered caffeine, low-caffeine green tea, on humans. The study design was a single-blind group comparison and participants (n=20) were randomly assigned to low-caffeine or placebo tea groups. These teas (≥500 mL/d), which were eluted with room temperature water, were taken from 1 week prior to pharmacy practice and continued for 10 d in the practice period...
2017: Biological & Pharmaceutical Bulletin
https://www.readbyqxmd.com/read/28520776/proteomic-analysis-of-tea-plants-camellia-sinensis-with-purple-young-shoots-during-leaf-development
#7
Qiongqiong Zhou, Zhidan Chen, Jinwook Lee, Xinghui Li, Weijiang Sun
Tea products made from purple leaves are highly preferred by consumers due to the health benefits. This study developed a proteome reference map related to color changes during leaf growth in tea (Camellia sinensis) plant with purple young shoots using two-dimensional electrophoresis (2-DE). Forty-six differentially expressed proteins were detected in the gel and successfully identified by using MALDI-TOF/TOF-MS. The pronounced changes in the proteomic profile between tender purple leaves (TPL) and mature green leaves (MGL) included: 1) the lower activity of proteins associated with CO2 assimilation, energy metabolism and photo flux efficiency and higher content of anthocyanins in TPL than those in MGL may protect tender leaves against photo-damage; 2) the higher abundance of chalcone synthase (CHS), chalcone isomerase (CHI) and flavonol synthase (FLS) likely contributes to the synthesis of anthocyanins, catechins and flavonols in TPL tissues; 3) higher abundance of stress response proteins, such as glutathione S-transferases (GST) and phospholipid hydroperoxide glutathione peroxidase (PHGPx), could enhance the tolerance of TPL tissues to adverse condition in; and 4) the increased abundance of proteins related to protein synthesis, nucleic acids and cell wall proteins should be beneficial for the proliferation and expansion of leaf cell in TPL tissues...
2017: PloS One
https://www.readbyqxmd.com/read/28515380/highly-selective-and-considerable-subcritical-butane-extraction-to-separate-abamectin-in-green-tea
#8
Yating Zhang, Lingbiao Gu, Fei Wang, Lingjun Kong, Huili Pang, Guangyong Qin
We specially carried out the subcritical butane extraction to separate abamectin from tea leaves. Four parameters, such as extraction temperature, extraction time, number of extraction cycles, and solid-liquid ratio were studied and optimized through the response surface methodology with design matrix developed by Box-Behnken. Seventeen experiments with three various factors and three variable levels were employed to investigate the effect of these parameters on the extraction of abamectin. Besides, catechins, theanine, caffeine, and aroma components were determined by both high-performance liquid chromatography and gas chromatography-mass spectrometry to evaluate the tea quality before and after the extraction...
May 17, 2017: Journal of Oleo Science
https://www.readbyqxmd.com/read/28511005/characterization-of-l-theanine-excitatory-actions-on-hippocampal-neurons-toward-the-generation-of-novel-n-methyl-d-aspartate-receptor-modulators-based-on-its-backbone
#9
Fatiha Sebih, Matthieu Rousset, Salima Bellahouel, Marc Rolland, Marie Celeste de Jesus Ferreira, Janique Guiramand, Catherine Cohen-Solal, Gérard Barbanel, Thierry Cens, Mohammed Abouazza, Adrien Tassou, Maud Gratuze, Céline Meusnier, Pierre Charnet, Michel Vignes, Valérie Rolland
l-Theanine (or l-γ-N-ethyl-glutamine) is the major amino acid found in Camellia sinensis. It has received much attention because of its pleiotropic physiological and pharmacological activities leading to health benefits in humans, especially. We describe here a new, easy, efficient, and environmentally friendly chemical synthesis of l-theanine and l-γ-N-propyl-Gln and their corresponding d-isomers. l-Theanine, and its derivatives obtained so far, exhibited partial coagonistic action at N-methyl-d-aspartate (NMDA) receptors, with no detectable agonist effect at other glutamate receptors, on cultured hippocampal neurons...
May 30, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28473262/the-tea-tree-genome-provides-insights-into-tea-flavor-and-independent-evolution-of-caffeine-biosynthesis
#10
En-Hua Xia, Hai-Bin Zhang, Jun Sheng, Kui Li, Qun-Jie Zhang, Changhoon Kim, Yun Zhang, Yuan Liu, Ting Zhu, Wei Li, Hui Huang, Yan Tong, Hong Nan, Cong Shi, Chao Shi, Jian-Jun Jiang, Shu-Yan Mao, Jun-Ying Jiao, Dan Zhang, Yuan Zhao, You-Jie Zhao, Li-Ping Zhang, Yun-Long Liu, Ben-Ying Liu, Yue Yu, Sheng-Fu Shao, De-Jiang Ni, Evan E Eichler, Li-Zhi Gao
Tea is the world's oldest and most popular caffeine-containing beverage with immense economic, medicinal, and cultural importance. Here, we present the first high-quality nucleotide sequence of the repeat-rich (80.9%), 3.02-Gb genome of the cultivated tea tree Camellia sinensis. We show that an extraordinarily large genome size of tea tree is resulted from the slow, steady, and long-term amplification of a few LTR retrotransposon families. In addition to a recent whole-genome duplication event, lineage-specific expansions of genes associated with flavonoid metabolic biosynthesis were discovered, which enhance catechin production, terpene enzyme activation, and stress tolerance, important features for tea flavor and adaptation...
June 5, 2017: Molecular Plant
https://www.readbyqxmd.com/read/28439281/l-theanine-content-and-related-gene-expression-novel-insights-into-theanine-biosynthesis-and-hydrolysis-among-different-tea-plant-camellia-sinensis-l-tissues-and-cultivars
#11
Zhi-Wei Liu, Zhi-Jun Wu, Hui Li, Yong-Xin Wang, Jing Zhuang
L-Theanine content has tissues and cultivars specificity in tea plant (Camellia sinensis L.), the correlations of theanine metabolic related genes expression profiles with theanine contents were explored in this study. L-theanine contents in the bud and 1st leaf, 2nd leaf, 3rd leaf, old leaf, stem, and lateral root were determined by HPLC from three C. sinensis cultivars, namely 'Huangjinya', 'Anjibaicha', and 'Yingshuang', respectively. The theanine contents in leaves and root of 'Huangjinya' were the highest, followed by 'Anjibaicha', and 'Yingshuang'...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28429900/theanine-the-unique-amino-acid-in-the-tea-plant-as-an-oral-hepatoprotective-agent
#12
REVIEW
Dongxu Wang, Qiang Gao, Taotao Wang, Frank Qian, Yijun Wang
For thousands of years, humans have consumed tea made from leaves of Camellia sinensis, first as a medicinal herb and then as a widely popular beverage. In the past 10 years, theanine, a tea-derived, unique, nonproteinic amino acid, has been extensively studied for its health benefits. Recently, multiple lines of evidence have proven its beneficial effects on hepatic and immune functions. One possible mechanism for its biological activity involves the downregulation of the inflammatory response through the induction of nitric oxide production and glutathione synthesis...
May 2017: Asia Pacific Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28416871/effect-of-water-quality-on-the-main-components-in-fuding-white-tea-infusions
#13
Haihua Zhang, Yulan Jiang, Yangjun Lv, Junxian Pan, Yuwei Duan, Yunyun Huang, Yuejin Zhu, Shikang Zhang, Kunkun Geng
The aim of this study was to investigate the effect of water quality on the main components in Fuding white tea infusions, including catechins, caffeine, theanine and free amino acids. Pure, tap and spring water were tested, and water quality was found to have a distinct effect on the main compounds extracted. Pure water, which was weakly acidic and low in dissolved ions, achieved the highest catechin content, whereas caffeine and theanine, and amino acids, were higher in infusions made with spring and tap water, respectively...
April 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28412808/spontaneously-assembled-nano-aggregates-in-clear-green-tea-infusions-from-camellia-ptilophylla-and-camellia-sinensis
#14
Xiaorong Lin, Xiong Gao, Zhongzheng Chen, Yuanyuan Zhang, Wei Luo, Xiaofei Li, Bin Li
Tea nano-aggregates spontaneously assembled in clear tea infusions are considered as the precursors of tea cream, although their molecular basis remains obscure. Here, we characterized nano-aggregates in green tea infusions from Camellia ptilophylla, a peculiar tea variety with 6.0% of theobromine, and Camellia sinensis as the control for comparative purpose. Numerous negatively charged spherical colloidal particles of 50-100 nm in diameter were primarily found in both green tea infusions. Catechins, proteins, and carbohydrates were confirmed as the dominant components in green tea nano-aggregates...
May 10, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28391425/safety-tolerability-and-efficacy-of-drugs-for-treating-behavioural-insomnia-in-children-with-attention-deficit-hyperactivity-disorder-a-systematic-review-with-methodological-quality-assessment
#15
REVIEW
Shweta Anand, Henry Tong, Frank M C Besag, Esther W Chan, Samuele Cortese, Ian C K Wong
OBJECTIVE: A large proportion of paediatric patients with attention-deficit/hyperactivity disorder (ADHD) have associated sleep problems which not only affect the child's wellbeing but also impact family functioning. Management of sleep problems is consequently an important aspect of overall ADHD management in paediatric patients. Although some drugs are being used off-label for the management of paediatric insomnia, there is scant clinical evidence supporting their use. Our aim was to identify and assess the quality of published studies reporting the safety, tolerability and efficacy of drugs used for treating behavioural insomnia in children with ADHD...
June 2017: Paediatric Drugs
https://www.readbyqxmd.com/read/28365292/evolving-transpeptidase-and-hydrolytic-variants-of-%C3%AE-glutamyl-transpeptidase-from-bacillus-licheniformis-by-targeted-mutations-of-conserved-residue-arg109-and-their-biotechnological-relevance
#16
Shruti Bindal, Sujata Sharma, Tej P Singh, Rani Gupta
γ-Glutamyl transpeptidase (GGT) catalyzes the transfer of the γ-glutamyl moiety from donor compounds such as l-glutamine (Gln) and glutathione (GSH) to an acceptor. During the biosynthesis of various γ-glutamyl-containing compounds using GGT enzyme, auto-transpeptidation reaction leads to the formation of unwanted byproducts. Therefore, in order to alter the auto-transpeptidase activity of the GGT enzyme, the binding affinity of Gln should be modified. Structural studies of the Bacillus licheniformis GGT (BlGT) complexed with the glutamic acid has shown that glutamic acid has strong ionic interactions through its α-carboxlic group with the guanidine moiety of Arg109...
March 30, 2017: Journal of Biotechnology
https://www.readbyqxmd.com/read/28358319/effective-subcritical-butane-extraction-of-bifenthrin-residue-in-black-tea
#17
Yating Zhang, Lingbiao Gu, Fei Wang, Lingjun Kong, Guangyong Qin
As a natural and healthy beverage, tea is widely enjoyed; however, the pesticide residues in tea leaves affect the quality and food safety. To develop a highly selective and efficient method for the facile removal of pesticide residues, the subcritical butane extraction (SBE) technique was employed, and three variables involving temperature, time and extraction cycles were studied. The optimum SBE conditions were found to be as follows: extraction temperature 45 °C, extraction time 30 min, number of extraction cycles 1, and in such a condition that the extraction efficiency reached as high as 92%...
March 30, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28332598/metabolic-flux-redirection-and-transcriptomic-reprogramming-in-the-albino-tea-cultivar-yu-jin-xiang-with-an-emphasis-on-catechin-production
#18
Guo-Feng Liu, Zhuo-Xiao Han, Lin Feng, Li-Ping Gao, Ming-Jun Gao, Margaret Y Gruber, Zhao-Liang Zhang, Tao Xia, Xiao-Chun Wan, Shu Wei
In this study, shade-induced conversion from a young pale/yellow leaf phenotype to a green leaf phenotype was studied using metabolic and transcriptomic profiling and the albino cultivar 'Yu-Jin-Xiang' ('YJX') of Camellia sinensis for a better understanding of mechanisms underlying the phenotype shift and the altered catechin and theanine production. Shaded leaf greening resulted from an increase in leaf chlorophyll and carotenoid abundance and chloroplast development. A total of 1,196 differentially expressed genes (DEGs) were identified between the 'YJX' pale and shaded green leaves, and these DEGs affected 'chloroplast organization' and 'response to high light' besides many other biological processes and pathways...
March 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28321230/integrated-transcriptome-and-metabolic-analyses-reveals-novel-insights-into-free-amino-acid-metabolism-in-huangjinya-tea-cultivar
#19
Qunfeng Zhang, Meiya Liu, Jianyun Ruan
The chlorotic tea variety Huangjinya, a natural mutant, contains enhanced levels of free amino acids in its leaves, which improves the drinking quality of its brewed tea. Consequently, this chlorotic mutant has a higher economic value than the non-chlorotic varieties. However, the molecular mechanisms behind the increased levels of free amino acids in this mutant are mostly unknown, as are the possible effects of this mutation on the overall metabolome and biosynthetic pathways in tea leaves. To gain further insight into the effects of chlorosis on the global metabolome and biosynthetic pathways in this mutant, Huangjinya plants were grown under normal and reduced sunlight, resulting in chlorotic and non-chlorotic leaves, respectively; their leaves were analyzed using transcriptomics as well as targeted and untargeted metabolomics...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28315395/acute-intravenous-administration-of-dietary-constituent-theanine-suppresses-noxious-neuronal-transmission-of-trigeminal-spinal-nucleus-caudalis-in-rats
#20
Shiori Takehana, Yoshiko Kubota, Nobuo Uotsu, Kei Yui, Yoshihito Shimazu, Mamoru Takeda
Theanine is a non-dietary amino acid linked to the modulation of synaptic transmission in the central nervous system, although the acute effects of theanine in vivo, particularly on nociceptive transmission in the trigeminal system, remain to be determined. The present study investigated whether acute intravenous theanine administration to rats attenuates the excitability of wide dynamic range (WDR) spinal trigeminal nucleus caudalis (SpVc) neurons in response to nociceptive and non-nociceptive mechanical stimulation in vivo...
March 15, 2017: Brain Research Bulletin
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