Publications

caffeine content of brewed teas.	caffeine is the world's most popular drug and can be found in many beverages including tea. it is a psychostimulant that is widely used to enhance alertness and improve performance. this study was conducted to determine the concentration of caffeine in 20 assorted commercial tea products. the teas were brewed under a variety of conditions including different serving sizes and steep-times. caffeine was isolated from the teas with liquid-liquid extraction and quantitated by gas chromatography with ...	2008	19007524
discrimination of teas with different degrees of fermentation by spme-gc analysis of the characteristic volatile flavour compounds.	as tea is traded all over the world, it is necessary for both customs officers and business investigators to develop an easy and reliable method to discriminate teas from each other. a total of 56 kinds of various green, oolong, and black teas were collected from different countries and markets, and their catechin contents and volatile flavour compounds (vfc) were compared by analyses, using hplc and solid-phase microextraction-gas chromatograph (spme-gc). it was found that neither total catechi ...	2008	26054281
coffee, tea, colas, and risk of epithelial ovarian cancer.	associations of coffee, tea, and other caffeinated beverages with ovarian cancer risk remain uncertain. in a population-based study in washington state, 781 women with epithelial ovarian cancer diagnosed in 2002 to 2005 and 1,263 controls completed self-administered questionnaires detailing consumption of caffeinated and noncaffeinated coffee, teas, and colas and in-person interviews regarding reproductive and hormonal exposures. we assessed risk associated with coffee, tea, and cola drinking an ...	2008	18349292
tea and health.	the possible beneficial effects of tea consumption in the prevention of cancer and cardiovascular diseases have been demonstrated in animal models and suggested by studies in vitro. similar beneficial effects, however, have not been convincingly demonstrated in humans: beneficial effects have been demonstrated in some studies but not in others. if such beneficial effects do exist in humans, they are likely to be mild, depending on many other lifestyle-related factors, and could be masked by conf ...	2008	10575676
mechanisms of action of antioxidants as exemplified in vegetables, tomatoes and tea.	most chronic diseases, including coronary heart disease and many types of cancer depend on the in vivo conversion of cellular macromolecules or of carcinogens to specific reactive, oxidized forms. for that reason, health promoting nutrition involves the daily intake of five to 10 vegetables and fruits, fruit juices, red wine and tea that are rich sources of micronutrients with antioxidant properties, including the antioxidant vitamins c, e and beta-carotene. tomatoes contain lycopene, a stable, ...	2007	10541449
tea drinking and haemostasis: a randomized, placebo-controlled, crossover study in free-living subjects.	the hypothesis that tea drinking may protect against coronary heart disease (chd) through effects on clotting as measured by plasma fibrinogen, tissue-type plasminogen activator (tpa) and plasminogen activator inhibitor-1 (pai-1) was tested in 65 healthy volunteers (31 men and 34 women; aged 20-74 years) in a randomized, blind, placebo-controlled, crossover study lasting 10 weeks (run-in phase 2 weeks, tea and placebo phases 4 weeks). during the placebo phase, intakes of milk, sugar, water and c ...	2007	8698279
identification and comparison of phenolic compounds in the preparation of oolong tea manufactured by semifermentation and drying processes.	oolong tea manufactured via a semifermentation process possesses a taste and color somewhere between green and black teas. alteration of constituents, particularly phenolic compounds, in the infusion of oolong tea resulting from its manufacture, was analyzed by high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry. the identified constituents contained 2 alkaloids, 11 flavan-3-ols, 8 organic acids and esters, 11 proanthocyanidin dimers, 3 theaflavins, ...	2007	17696450
both aluminum and polyphenols in green tea decoction (camellia sinensis) affect iron status and hematological parameters in rats.	green tea leaves naturally contain high levels of polyphenols and aluminum (al). polyphenols in green tea decoction are considered to be one of the major factors responsible of low iron status. however, the effects of al from green tea decoction on iron status and hematological parameters remained unclear.	2007	18060378
in vitro and in vivo anti-allergic effects of 'benifuuki' green tea containing o-methylated catechin and ginger extract enhancement.	'benifuuki', a tea (camellia sinensis l.) cultivar in japan, is rich in anti-allergic epigallocatechin-3-o-(3-o-methyl) gallate (egcg3''me). 'benifuuki' green tea and simultaneous addition of ginger extract remarkably suppressed cytokine (tnf-alpha and mip-1alpha) secretion from mouse bone marrow-derived mast cells after antigen stimulation and, as expected, suppressed delay-type allergy. after drinking 'benifuuki' green tea containing 43.5 mg of egcg and 8.5 mg of egcg3''me, the auc (area under ...	2007	19003003
the study of antioxidant and anticarcinogenic green tea and black tea.	tea is one of the most popular beverages consumed worldwide. the relationship between tea consumption and human cancer incidence is an important concern. the effect of tea extract and ingredients, polyphenol and caffeine on the mutagenicity of sodium azide was examined in vitro by using salmonella typhimurium ta100, ta98 and ta1535 in the presence of induced rat liver s9 fractions. experimental studies have demonstrated the significant antimutagenic and anticarcinogenic effects of both green and ...	2007	19069905
modulatory effects of black tea polyphenols on rat forestomach carcinogenesis.	abstract the present study was designed to evaluate the chemopreventive effects of black tea polyphenols (polyphenon-b) on n-methyl-n'-nitro-n-nitrosoguanidine (mnng)-induced gastric carcinogenesis in wistar rats. intragastric administration of mnng induced well-differentiated squamous cell carcinomas that showed diminished mitochondrial lipid and protein oxidation and an increase in antioxidants. in contrast to tumor tissue, the liver mitochondria of tumor-bearing animals showed elevated lipid ...	2007	20020873
monitoring the binding processes of black tea thearubigin to the bovine serum albumin surface using quartz crystal microbalance with dissipation monitoring.	the binding processes of thearubigin, which is one of the two major polyphenols (the other one is theaflavin) that gives black tea its characteristic color and taste, to the bovine serum albumin (bsa) surface have been investigated by quartz crystal microbalance with dissipation monitoring (qcm-d). the mass and thickness of the thearubigin adlayer on bsa surfaces at various thearubigin concentrations, salt concentrations, and ph values have been determined by qcm-d using the voigt model. our res ...	2007	18031008
a major ingredient of green tea rescues mice from lethal sepsis partly by inhibiting hmgb1.	the pathogenesis of sepsis is mediated in part by bacterial endotoxin, which stimulates macrophages/monocytes to sequentially release early (e.g., tnf, il-1, and ifn-gamma) and late (e.g., hmgb1) pro-inflammatory cytokines. our recent discovery of hmgb1 as a late mediator of lethal sepsis has prompted investigation for development of new experimental therapeutics. we previously reported that green tea brewed from the leaves of the plant camellia sinensis is effective in inhibiting endotoxin-indu ...	2007	17987129
theaflavins induce g2/m arrest by modulating expression of p21waf1/cip1, cdc25c and cyclin b in human prostate carcinoma pc-3 cells.	cancer of the prostate gland (pca) is the most common invasive malignancy and is the second leading cause of cancer-related death in males. the polyphenolic constituents of black tea have gained considerable attention as chemopreventive agents. many studies have shown that black tea reduces the risk of several cancer types. in the present study, we studied the effect of a black tea polyphenol, theaflavin (tf), on cellular proliferation and cell death in the human prostate cancer cell line, pc-3. ...	2007	17936851
serological detection and immunogold localization of cross-reactive antigens shared by camellia sinensis and exobasidium vexans.	pathogenicity of exobasidium vexans, causal agent of blister blight of tea, was studied in 30 commercially cultivated tea varieties by analysing the antigenic patterns of host and pathogen using immunological techniques.	2007	17953578
productivity and biochemical properties of green tea in response to full-length and functional fragments of hpag xooc, a harpin protein from the bacterial rice leaf streak pathogen xanthomonas oryzae pv. oryzicola.	harpin proteins from plant pathogenic bacteria can stimulate hypersensitive cell death (hcd), drought tolerance, defence responses against pathogens and insects in plants, as well as enhance plant growth. recently, we identified nine functional fragments of hpag;xooc, a harpin protein from xanthomonas oryzae pv.oryzicola, the pathogen that causes bacterial leaf streak in rice. fragments hpag;1-94'hpag;10-42, and hpag;62-138, which contain the hpag;xooc regions of the amino acid sequence as indic ...	2007	17954972
modulation of the oxidative stress and nuclear factor kappab activation by theaflavin 3,3'-gallate in the rats exposed to cerebral ischemia-reperfusion.	the major pathobiological mechanisms of ir injury include excitotoxicity, oxidative stress, and inflammation. tf3, a major constituent of black tea, possesses biological functions such as anti-oxidative and anti-inflammatory activities. the purpose of this study was to verify the neuronal protective potential of tf3 and its mechanisms against cerebral ir injury in rats. tf3 administration (10 and 20 mg.kg-1) ameliorated the infarct volume. tf3 also decreased the content of mda and no. tf3 signif ...	2007	17976306
epigallocatechin-3-o-gallate inhibits the angiotensin ii-induced adhesion molecule expression in human umbilical vein endothelial cell via inhibition of mapk pathways.	epigallocatechin-3-o-gallate (egcg) is the main catechin, which is derived from camellia sinensis plant. vascular cell adhesion molecules (vcams) and intercellular adhesion molecules (icams) mediate the binding of inflammatory cells onto the vascular wall-promoting the early phase of atherosclerosis. in the present study, we investigated the mechanism(s) by which egcg inhibits angiotensin ii (ang ii)-induced elevation of the membrane associated vcam-1 and icam-1 in human umbilical vein endotheli ...	2007	17982268
theaflavins attenuate hepatic lipid accumulation through activating ampk in human hepg2 cells.	black tea is one of the world's most popular beverages, and its health-promoting effects have been intensively investigated. the antiobesity and hypolipidemic effects of black tea have attracted increasing interest, but the mechanisms underlying these phenomena remain unclear. in the present study, the black tea major component theaflavins were assessed for their hepatic lipid-lowering potential when administered in fatty acid overload conditions both in cell culture and in an animal experimenta ...	2007	17720960
inhibition of 17alpha-hydroxylase/c17,20-lyase (cyp17) from rat testis by green tea catechins and black tea theaflavins.	in the course of screening for 17alpha-hydroxylase/c17,20-lyase inhibitors from food ingredients, the methanol soluble fraction of green tea and black tea, which were expected to be rich in catechin and theaflavin content, showed potent inhibitory activity. (-)-epigallocathechin gallate and theaflavin 3-o-gallate with a pirogallol moiety significantly inhibited c17,20-lyase activity on ic50 values of 24.5 microm and 11.5 microm respectively. they had potent cytotoxicity against human prostate ca ...	2007	17827674
polyphenols as potential indicators for drought tolerance in tea (camellia sinensis l.).	plant polyphenols have gained prominence in quality of plant products and in human health. an experiment was conducted to determine the association of tea polyphenols with water stress and their suitability as indicators for drought tolerance. the experiment was conducted in a 'rain-out' shelter, and consisted of six tea clones (bbk 35, trfk 6/8, trfk 76/1, trfk 395/2, trfk 31/30, and trfk 311/287) and four levels of soil water contents (38, 30, 22, and 14% v/v), which were maintained for a peri ...	2007	17827703
phenolic antioxidants identified by esi-ms from yerba maté (ilex paraguariensis) and green tea (camelia sinensis) extracts.	aqueous extracts of green yerba maté (ilex paraguariensis) and green tea (camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. the subject of this study were organic extracts from yerba maté, both green and roasted, and from green tea. their phenolic profiles were characterized by direct infusion electrospray insertion mass spectrometry (esi-ms) and their free radical scavenging activity was determined by the dpph assay. organic extracts containin ...	2007	17851401
effect of extraction conditions on measured total polyphenol contents and antioxidant and antibacterial activities of black tea.	black tea was extracted for 2, 8 and 18 h with absolute acetone, n,n-dimethyl-formamide (dmf), ethanol and methanol and their 50% aqueous solutions. the extracts were screened for total polyphenol contents, antioxidant and antibacterial activities. the polyphenol content of the extracts was found to be in the range of 0.44-114.01 mg gallic acid equivalents (gae)/g dry weight tea, depending on the solvent used and the length of the extraction process. in general, aqueous acetone or dmf extracts d ...	2007	17851405
cellular responses and proteomic analysis of escherichia coli exposed to green tea polyphenols.	the purpose of this study was to characterize the cellular response and proteomic analysis of escherichia coli exposed to tea polyphenols (tpp) extracted from korean green tea (camellia sinensis l). tpp showed a dose-dependent bactericidal effect on e. coli. analysis of cell-membrane fatty acids of e. coli cultures treated with tpp identified unique changes in saturated and unsaturated fatty acids, whereas scanning electron microscopic analysis demonstrated the presence of perforations and irreg ...	2007	17874165
inhibitory effects of various beverages on human recombinant sulfotransferase isoforms sult1a1 and sult1a3.	sulfotransferase (sult) 1a1 and sult1a3 play important roles in the presystemic inactivation of beta(2) agonists in the liver and intestine, respectively. the study aimed to investigate the inhibitory effects of grapefruit juice, orange juice, green tea, black tea and oolong tea and their constituents on the activities of sult1a1 and sult1a3. the activities of both sult1a1 and sult1a3 were significantly inhibited by all the beverages investigated at a concentration of 10%. the beverage constitue ...	2007	17876860
specific formulation of camellia sinensis prevents cold and flu symptoms and enhances gamma,delta t cell function: a randomized, double-blind, placebo-controlled study.	determine if a specific formulation of camellia sinensis (csf) can prevent illness and symptoms due to cold and flu, and enhance gammadelta t cell function	2007	17914132
redox potential of tea infusion as an index for the degree of fermentation.	redox potential of tea infusion is suggested as an index for the extent of tea fermentation. the potential was measured between platinum and ag/agcl electrode pair with a voltmeter with high input impedance (>1000 gohms). phosphate buffer (10 mm, ph 7.0) was used to extract the infusion and served as the supporting electrolytes for the electrochemical measurement. the reliability (the nernst's behavior) for redox potential measurement was verified with a standard redox couple, ferricyanide/ferro ...	2007	17560382
antibacterial properties of traditionally used indian medicinal plants.	in search of broad-spectrum antibacterial activity from traditionally used indian medicinal plants, 66 ethanolic plant extracts were screened against nine different bacteria. of these, 39 extracts demonstrated activity against six or more test bacteria. twelve extracts showing broad-spectrum activity were tested against specific multidrug-resistant (mdr) bacteria, methicillin-resistant staphylococcus aureus (mrsa) and extended spectrum beta-lactamases (esbetal)-producing enteric bacteria. in vit ...	2007	17440624
ecological impact of solar ultraviolet-b (uv-b: 320-290 nm) radiation on corynebacterium aquaticum and xanthomonas sp. colonization on tea phyllosphere in relation to blister blight disease incidence in the field.	to assess the effects of solar uv-b radiation on phyllosphere bacteria of tea leaves in relation to blister blight disease in the field.	2007	17451518
theaflavins induced apoptosis of lncap cells is mediated through induction of p53, down-regulation of nf-kappa b and mitogen-activated protein kinases pathways.	prostate cancer (pca), the most frequently diagnosed malignancy in men, represents an excellent candidate disease for chemoprevention studies because of its particularly long latency period, high rate of mortality and morbidity. infusion of black tea and its polyphenolic constituents have been shown to possess antineoplastic effects in androgen dependent pca in both in vivo and in vitro models including transgenic animals. in the present study, we report that black tea polyphenol, theaflavins (t ...	2007	17499812
modulatory effects of black tea polyphenols on oxidant-antioxidant profile and expression of proliferation, apoptosis, and angiogenesis-associated proteins in the rat forestomach carcinogenesis model.	chemoprevention by dietary constituents has emerged as a novel approach to control stomach cancer incidence. we therefore evaluated the chemopreventive effects of black tea polyphenols (polyphenon-b) on oxidant-antioxidant status, cell proliferation, apoptosis, and angiogenesis during n-methyl-n'-nitro-n-nitrosoguanidine (mnng)-induced gastric carcinogenesis.	2007	17530359
salivary hydrogen peroxide produced by holding or chewing green tea in the oral cavity.	tea (camellia sinensis) catechins have been studied for disease prevention. these compounds undergo oxidation and produce h(2)o(2). we have previously shown that holding tea solution or chewing tea leaves generates high salivary catechin levels. herein, we examined the generation of h(2)o(2) in the oral cavity by green tea solution or leaves. human volunteers holding green tea solution (0.1-0.6%) developed salivary h(2)o(2) with c(max) = 2.9-9.6 microm and auc(0 --> infinity) = 8.5-285.3 microm ...	2007	17577746
chemical profiling and gene expression profiling during the manufacturing process of taiwan oolong tea "oriental beauty".	oriental beauty, which is made from tea leaves infested by the tea green leafhopper (jacobiasca formosana) in taiwan, has a unique aroma like ripe fruits and honey. to determine what occurs in the tea leaves during the oolong tea manufacturing process, the gene expression profiles and the chemical profiles were investigated. tea samples were prepared from camellia sinensis var. sinensis cv. chin-shin dah-pang while the tea leaves were attacked by the insect. the main volatile compounds, such as ...	2007	17587678
artemisia herba-alba asso (asteraceae) has equivalent effects to green and black tea decoctions on antioxidant processes and some metabolic parameters in rats.	the objective was to compare the long-term effects of artemisia herba-alba asso decoction with a green or black tea decoction, prepared without sugar, on the antioxidant processes in rats.	2007	17587792
elevation protective role of camellia sinensis and urtica dioica infusion against trichloroacetic acid-exposed in rats.	this study was designed to investigate the protective effects of two traditionally used turkish medicinal plants, camellia sinensis (cs) and urtica dioica l. (ud), beverages used against chemical carcinogen trichloroacetic acid (tca)-exposure in rats. the preventive potential of the plant infusions was evaluated by measuring the level of serum marker enzymes, aspartate aminotransferase (ast), alanine aminotransferase (alt), creatine phosphokinase (cpk), acid phosphatase (acp), alkaline phosphata ...	2007	17622976
expression and purification of his-tagged flavonol synthase of camellia sinensis from escherichia coli.	flavonols, a class of bioactive polyphenols present in plants, are the products of flavonol desaturation catalyzed by flavonol synthase (fls). we cloned the cdna coding for the enzyme fls from camellia sinensis (csfls) by end-to-end pcr followed by 5'- and 3'-race. the putative csfls had 333 amino acid residues, displayed identities to the flss of arabidopsis and ginkgo of 53% and 52.5%, respectively, and contained several conserved elements found in the 2-oxoglutarate-fe(ii)-dioxygenase superfa ...	2007	17629496
black tea-induced decrease in il-10 and tgf-beta of tumor cells promotes th1/tc1 response in tumor bearer.	several lines of evidence support that impairment of host immune function by tumor may be related to several strategies of tumor escape from immunosurveillance. we found that in ehrlich's ascites carcinoma (eac)-bearing mice, the tumor cells secrete immunosuppressive cytokines, transforming growth factor beta (tgf-beta) and interleukin-10 (il-10) that induce a general t helper cells type 2 (th2) dominance dampening the t cytotoxic cells type 1 (tc1) population. interestingly, black tea at the an ...	2007	17640168
studies of the antioxidative effects of green and black tea (camellia sinensis) extracts in rats.	this paper reports a comparative study of the antioxidative effects of black and green tea extracts in sodium oxalate-challenged rats. a dose of 10 mg/kg of body weight of sodium oxalate was used to induce lipid peroxidation in vivo. rats treated with sodium oxalate had 42.06 +/- 3.10 nm/hour, 45.39 +/- 9.75 mg/100 ml, 10.95 +/- 1.52%, 15.95 +/- 3.19 mg/dl, 112.25 +/- 5.15 mg/dl, 59.21 +/- 2.95 iu, 39.55 +/- 2.51 iu, and 150.62 +/- 9.62 ka/unit for serum levels of malondialdehyde, reduced ascorb ...	2007	17651072
the effect of green, black and white tea on the level of alpha and gamma tocopherols in free radical-induced oxidative damage of human red blood cells.	the present study was undertaken to investigate the effect of aqueous tea extracts on lipid peroxidation and alpha and gamma tocopherols concentration in the oxidative damage of human red blood cells (rbc). rbc was taken as the model for study of the oxidative damage was induced by cumene hydroperoxide (cumooh). the antioxidative property of leaf green tea, leaf and granulate of black tea and white tea at levels 1, 2, 4 g/150 ml of water were evaluated. the correlation was observed between reduc ...	2007	17665865
amelioration by black tea of sodium fluoride-induced changes in protein content of cerebral hemisphere, cerebellum and medulla oblongata in brain region of mice.	oral administration of sodium fluoride (naf, 6 and 12 mg/kg body weight/day) to swiss strain male albino mice for 30 days caused significant dose-dependant reduction in the content of acidic, basic, neutral, and total protein in cerebral hemisphere, cerebellum and medulla oblongata region of brain. after 30 days of naf treatment, followed by withdrawal of treatment for 30 days, partial but significant amelioration occurred. administration of 2% black tea extract alone for 30 days did not cause a ...	2007	17695144
tea and cancer chemoprevention: a comprehensive review.	dietary components that are capable of inhibiting the growth of cancer cells without affecting the growth of normal cells are receiving considerable attention in developing novel cancer-preventive approaches. tea, made from young leaves and leaf buds of the tea plant, 'camellia sinensis', and the world's second most consumed beverage, has received a great deal of attention both from the general public and the scientific community because tea polyphenols are strong antioxidants, and tea preparati ...	2007	17696725
influence of regular black tea consumption on tobacco associated dna damage and hpv prevalence in human oral mucosa.	black tea is more widely consumed than green tea worldwide, particularly in india. therefore, it is necessary to focus attention on black tea with respect to its health promoting and anti-cancer actions. in order to establish the concept that black tea is a potential candidate for cancer prevention, it is important to provide epidemiological evidence derived from investigations of human populations. in view of this, the objective of the present study was to determine the correlation between natu ...	2007	17696743
black tea-induced amelioration of hepatic oxidative stress through antioxidative activity in eac-bearing mice.	it is recognized that during cancer, the disease itself as well as many of the anticancer drugs in use produce undesirable side effects such as hepatotoxicity. we have already demonstrated the antitumor and immunorestoring effects of black tea. here we report ehrlich's ascites carcinoma (eac)induced hepatotoxicity and its protection by antitumor dose of black tea in mice. hepatotoxicity was adjudged by liver histopathology and by measurement of plasma level of alkaline phosphatase (alp). an atte ...	2007	18197822
in vitro mitigation of arsenic toxicity by tea polyphenols in human lymphocytes.	the groundwater arsenicals have brought dreadful misery for the people residing in the endemic regions of west bengal, india. arsenic-related anomalies include arsenicosis, hyperkera-tosis, gastric complications, liver fibrosis, peripheral neuropathy, and cancer. some of these diseases have been frequently associated with overproduction of reactive oxygen species that cause dna damage and improper functioning of body's antioxidant defense mechanism. natural polyphenols present in tea serve as ex ...	2007	18197836
effect of nr-anx-c (a polyherbal formulation) on haloperidol induced catalepsy in albino mice.	use of typical antipsychotics like haloperidol in treatment of schizophrenia is associated with a high incidence of extrapyramidal side effects. in rodents, administration of haloperidol leads to the development of a behavioural state called catalepsy, in which the animal is not able to correct an externally imposed posture. in the present study we evaluated the anticataleptic efficacy of nr-anx-c, a polyherbal formulation containing bioactives of withania somnifera, ocimum sanctum, camellia sin ...	2007	18160755
selective microbiologic effects of tea extract on certain antibiotics against escherichia coli in vitro.	this study evaluated the microbiologic effects of black tea, compared to green tea, alone and in conjunction with selected antibiotics against escherichia coli, the common cause of intestinal and urinary tract infections.	2007	18166124
green tea polyphenols and its constituent epigallocatechin gallate inhibits proliferation of human breast cancer cells in vitro and in vivo.	tea [camellia sinensis (theaceae)] intake is second only to water in terms of worldwide popularity as a beverage. the green tea polyphenols have been shown to have a protective effect in prostate cancer in various pre-clinical animal models and has been reported to be effective in several other cancer types as well. an inverse association between the risk of breast cancer and the intake of green tea has also been reported in asian americans. several epidemiological studies have shown that breast ...	2007	16519995
green tea and skin cancer: photoimmunology, angiogenesis and dna repair.	human skin is constantly exposed to numerous noxious physical, chemical and environmental agents. some of these agents directly or indirectly adversely affect the skin. cutaneous overexposure to environmental solar ultraviolet (uv) radiation (290-400 nm) has a variety of adverse effects on human health, including the development of melanoma and nonmelanoma skin cancers. therefore, there is a need to develop measures or strategies, and nutritional components are increasingly being explored for th ...	2007	17049833
membrane filtration - atomic absorption spectrometry combination for copper, cobalt, cadmium, lead and chromium in environmental samples.	cellulose nitrate membrane filter was used for the preconcentration-separation of cu, co, cd, pb and cr ions. the analyte ions were collected on the membrane filter by the aid of carmine. then membrane filter was dissolved by using nitric acid. the levels of the analytes in the final solutions were determined by flame atomic absorption spectrometry (faas). the analytical parameters including ph, amounts of carmine, sample volumes etc. have been optimized. no influences have been observed from th ...	2007	17058008
overview of antibacterial, antitoxin, antiviral, and antifungal activities of tea flavonoids and teas.	tea leaves produce organic compounds that may be involved in the defense of the plants against invading pathogens including insects, bacteria, fungi, and viruses. these metabolites include polyphenolic compounds, the six so-called catechins, and the methyl-xanthine alkaloids caffeine, theobromine, and theophylline. postharvest inactivation of phenol oxidases in green tea leaves prevents oxidation of the catechins, whereas postharvest enzyme-catalyzed oxidation (fermentation) of catechins in tea ...	2007	17195249
in vitro evaluation of the anticancer effect of lactoferrin and tea polyphenol combination on oral carcinoma cells.	we investigated the anticancer effects of green and black tea polyphenols alone and in combination with bovine milk lactoferrin (blf) on human tongue squamous carcinoma (cal-27) and normal human gingival fibroblast (hgf) cells. both green (polyphenon-e;p-e) and black tea polyphenols (polyphenon-b;p-b) preferentially inhibit the growth of cal-27 cells in a dose-dependent manner. based on the ic(50) values, p-e was found to be more effective than p-b and the combination of p-e and blf (1:2 ratio) ...	2007	17258915
bioactive saponins and glycosides. xxviii. new triterpene saponins, foliatheasaponins i, ii, iii, iv, and v, from tencha (the leaves of camellia sinensis).	new triterpene saponins, foliatheasaponins i-v, were isolated from the methanolic extract of tencha [the leaves of camellia sinensis (l.) o. kuntze (theaceae)]. the chemical structures of these new saponins were elucidated on the basis of chemical and physicochemical evidence. among the new saponins, foliatheasaponins ii and iii, were found to inhibit release of beta-hexosaminidase, as a marker of antigen-induced degranulation, in rbl-2h3 cells.	2007	17268104
evaluation of the astringency of black tea by a taste sensor system: scope and limitation.	grading the astringency of black tea by a taste sensor system was studied. the black tea samples manufactured in india and sri lanka were classified into ten steps on the basis of two standard solutions (0.65 mm and 0.26 mm egcg aqueous solutions). an organoleptic test demonstrated that the sensor output was correlative to the human gustatory sense.	2007	17284831
black tea prevents cigarette smoke-induced apoptosis and lung damage.	cigarette smoking is a major cause of lung damage. one prominent deleterious effect of cigarette smoke is oxidative stress. oxidative stress may lead to apoptosis and lung injury. since black tea has antioxidant property, we examined the preventive effect of black tea on cigarette smoke-induced oxidative damage, apoptosis and lung injury in a guinea pig model.	2007	17300721
thea sinensis melanin prevents cisplatin-induced nephrotoxicity in mice.	the preventive effect of thea sinensis melanin (tsm) against cisplatin-induced nephrotoxicity was studied on icr mice. animals were given 20mg/kg i.p. of cisplatin, and tsm was injected i.p. in doses 10-40 mg/kg 2h before intoxication. the protective effects were evidenced by a complete inhibition of the cisplatin-induced elevation of serum blood urea nitrogen (bun), prevention of oxidative stress, and complete blockade of cisplatin-induced elevation of serum creatinine. tsm by itself, however, ...	2007	17303299
compositional analysis and preliminary toxicological evaluation of a tea polysaccharide conjugate.	tea polysaccharide conjugate is one of the main bioactive constituents of tea (camellia sinensis l.). the chemical composition and preliminary toxicological evaluation of a tea polysaccharide conjugate was investigated to determine the possibility of using it for human consumption. chemical analysis of tea polysaccharide conjugate showed that the tea polysaccharide conjugate was a nonstarch protein bounded acidic polysaccharide. the protein, neutral sugar, and uronic acid content of the tea poly ...	2007	17305361
biosorption of copper(ii), lead(ii), iron(iii) and cobalt(ii) on bacillus sphaericus-loaded diaion sp-850 resin.	the biosorption of copper(ii), lead(ii), iron(iii) and cobalt(ii) on bacillus sphaericus-loaded diaion sp-850 resin for preconcentration-separation of them have been investigated. the sorbed analytes on biosorbent were eluted by using 1 mol l(-1) hcl and analytes were determined by flame atomic absorption spectrometry. the influences of analytical parameters including amounts of ph, b. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. the effects of alk ...	2007	17386450
evaluation of chemopreventive agents for genotoxic activity.	we conducted genetic toxicity evaluations of 11 candidate chemopreventive agents with the potential for inhibiting carcinogenesis in humans at increased risk of cancer. the compounds were evaluated for bacterial mutagenesis in the salmonella-e. coli assay, for mammalian mutagenesis in mouse lymphoma cells, for chromosome aberrations in chinese hamster ovary (cho) cells, and for micronucleus induction in mouse bone marrow. tested agents were indole 3-carbinol (i3c), bowman-birk inhibitor concentr ...	2007	17387038
use of tea extracts (camelia sinensis) in jelly candies as polyphenols sources in human diet.	diet rich in polyphenols may be important factor in preventing cardiovascular, neoplastic diseases and slowing down the aging processes. because tea (camelia sinensis) is most popular beverage containing relatively large amounts of polyphenols, it could be tremendously important source of polyphenolic constituents in human diet. however, there has been no data on the tea extracts use in particular everyday snacks. objective of the study was to investigate potential use of tea polyphenol extracts ...	2007	17392075
addition of milk prevents vascular protective effects of tea.	experimental and clinical studies indicate that tea exerts protection against cardiovascular diseases. however, a question of much debate is whether addition of milk modifies the biological activities of tea. we studied the vascular effects of tea, with or without milk, in humans and elucidated the impact of individual milk proteins in cell culture experiments, with isolated rat aortic rings and by hplc analysis.	2007	17213230
structure-activity relationships of tea compounds against human cancer cells.	the content of the biologically active amino acid theanine in 15 commercial black, green, specialty, and herbal tea leaves was determined as the 2,4-dinitrophenyltheanine derivative (dnp-theanine) by a validated hplc method. to define relative anticarcinogenic potencies of tea compounds and teas, nine green tea catechins, three black tea theaflavins, and theanine as well as aqueous and 80% ethanol/water extracts of the same tea leaves were evaluated for their ability to induce cell death in huma ...	2007	17227049
tea and cancer prevention: molecular mechanisms and human relevance.	tea made from the leaves of the plant camellia sinensis is a popular beverage. the possible cancer-preventive activity of tea and tea polyphenols has been studied extensively. this article briefly reviews studies in animal models, cell lines, and possible relevance of these studies to the prevention of human cancer. the cancer-preventive activity of tea constituents have been demonstrated in many animal models including cancer of the skin, lung, oral cavity, esophagus, stomach, liver, pancreas, ...	2007	17234229
breast cancer prevention by green tea catechins and black tea theaflavins in the c3(1) sv40 t,t antigen transgenic mouse model is accompanied by increased apoptosis and a decrease in oxidative dna adducts.	tea consumption is associated with a reduced risk of mammary cancer as reflected by epidemiological studies and experiments in carcinogen-induced rodent models of mammary carcinogenesis. we tested the hypothesis that green tea catechins (gtc) or theaflavins from black tea (btt) interfere with mammary carcinogenesis in c3(1) sv40 t,t antigen transgenic multiple mammary adenocarcinoma (tag) mice and that gtc/btt affect tumor survival or oxidation status. tag mice received gtc/btt (0.05%) in drinki ...	2007	17407311
acute effects of tea on fasting and non-fasting plasma total homocysteine concentrations in human subjects.	plasma total homocysteine concentrations (thcy) are a putative risk factor for cvd. tea is a rich dietary source of polyphenols and caffeine, both of which may raise thcy. however, it is possible that much of any effect is transitory and may be influenced by the consumption of food. our objective was to investigate the acute effect of tea, at a dose representative of ordinary population intakes, on thcy and to determine whether consumption of a meal influences the magnitude of any effect. measur ...	2007	17408524
medicinal flowers. xiv. new acylated oleanane-type triterpene oligoglycosides with antiallergic activity from flower buds of chinese tea plant (camellia sinensis).	the methanolic extract from the flower buds of chinese tea plant (camellia sinensis (l.) o. kuntze) was found to inhibit release of beta-hexosaminidase from rbl-2h3 cells. from the methanolic extract, six new acylated oleanane-type triterpene oligoglycosides, floratheasaponins d-i, were isolated together with 21 known compounds including floratheasaponins a-c. the chemical structures of floratheasaponins d-i were elucidated on the basis of chemical and physicochemical evidence. the principal con ...	2007	17409555
chemoprevention of rat mammary carcinogenesis by black tea polyphenols: modulation of xenobiotic-metabolizing enzymes, oxidative stress, cell proliferation, apoptosis, and angiogenesis.	chemoprevention of dietary constituents has emerged as a cost-effective approach to control the incidence of breast cancer. the present study was therefore designed to evaluate the chemopreventive efficacy of black tea polyphenols (polyphenon-b) during the preinitiation phase of 7,12-dimethylbenz[a]anthracene (dmba) induced mammary carcinogenesis using xenobiotic-metabolizing enzymes, cellular redox status, cell proliferation, apoptosis, and angiogenesis as biomarkers of chemoprevention. intraga ...	2007	17415784
study on the antioxidant activity of tea flowers (camellia sinensis).	major chemical compounds in different extracts from tea flowers (camellia sinensis) were analyzed. distilled water or 70% ethanol extracts were then fractionated with chloroform, ethyl acetate and n-butanol, respectively. each extract fraction was tested its scavenging activities on 2,2-diphenyl-1-picrylhydrazyl (dpph) and hydroxyl free radicals. the results showed that ethyl acetate fraction of ethanol-extract of tea flower (eea) exhibited the highest quenching activity to hydroxyl radicals (sc ...	2007	17392094
high-molecular-weight polyphenols from oolong tea and black tea: purification, some properties, and role in increasing mitochondrial membrane potential.	high-molecular-weight polyphenols from oolong and black teas increased mitochondrial membrane potential, as measured by a method using ciliated protozoan tetrahymena and rhodamine 123. these polyphenols, referred to as mitochondrial activation factors (mafs), were purified from oolong and black teas by solvent extraction and toyopearl column chromatography. the number-average molecular weights of the mafs were 9,000 to 18,000, and the weight-average molecular weights were 15,000 to 25,000. the m ...	2007	17341825
oxidative coupling of the pyrogallol b-ring with a galloyl group during enzymatic oxidation of epigallocatechin 3-o-gallate.	in order to clarify the mechanism for formation of catechin oligomers during the fermentation stage of black tea manufacture, epigallocatechin-3-o-gallate, the most abundant tea flavanol in fresh tea leaves, was enzymatically oxidized and the resulting unstable quinone metabolites were converted to phenazine derivatives by treatment with o-phenylenediamine. in addition to formation of monomeric and dimeric derivatives, four trimeric derivatives were isolated whose structures were determined by a ...	2007	17320123
dissipation kinetics of spiromesifen on tea (camellia sinensis) under tropical conditions.	spiromesifen (oberon) is a new insecticide and miticide of chemical class ketoenol active against white flies (bemisia spp., trialeuroides spp.) and spider mites (tetranychus and panonychus spp.). due to its potential significance in insect resistance management, it is important to establish its behaviour on crop and environment. in the present study, the degradation/dissipation of spiromesifen on tea crop under tropical environmental conditions was studied and its dt(50) (t(1/2)), and dt(90) (t ...	2007	17307225
inhibition of folic acid uptake by catechins and tea extracts in caco-2 cells.	in this present study it was aimed to determine whether the catechins contained in green tea and the whole extracts of camellia sinensis (theaceae) inhibit the uptake of folic acid by caco-2 cell monolayers. our results indicate that (-)-epigallocatechin 3-gallate (egcg) and (-)-epicatechin 3-gallate (ecg) inhibit cellular folic acid uptake with ic50 values of 34.8 micromol/l and 30.8 micromol/l, respectively. furthermore, green and black tea extracts were also found to inhibit folic acid uptake ...	2007	17117344
molecular targets of tea polyphenols in the cardiovascular system.	tea-derived polyphenols have attracted considerable attention in the prevention of cancer and cardiovascular diseases. in comparison to tumour cells, the elucidation of their molecular targets in cardiovascular relevant cells is still at the beginning. although promising experimental and clinical data demonstrate protective effects for the cardiovascular system, little information is actually available on how these beneficial effects of tea polyphenols are mediated at the cellular level. by affe ...	2007	17020753
the effects of chronic tea intake on platelet activation and inflammation: a double-blind placebo controlled trial.	tea drinking appears to protect against the development of coronary heart disease (chd), but the mediating pathways are uncertain. we studied the effects of 6 weeks of black tea or placebo on platelet activation, c-reactive protein (crp), total antioxidant status, and soluble (s) p-selectin in a randomized double-blind trial.	2007	17010979
black tea--helpful or harmful? a review of the evidence.	to consider whether consumption of black tea has a positive or negative impact on health.	2007	16855537
effect of liming and seasonal variation on lead concentration of tea plant (camellia sinensis (l.) o. kuntze).	tea is a widely consumed beverage. however, recent studies revealed that there were an increasing number of cases of tea products exceeding the former maximum permissible concentration (mpc) in china for pb (2 mg kg(-1)). tea pb contamination is an issue affecting trade and consumer confidence. root uptake of pb could contribute significantly to pb accumulation in tea leaves due to the strong acidity of many tea garden soils. we conducted pot and field experiments to evaluate the effect of limin ...	2007	16844190
the effect of an extract of green and black tea on glucose control in adults with type 2 diabetes mellitus: double-blind randomized study.	recent evidence suggests that tea from camellia sinensis (eg, green, oolong, and black tea) may have a hypoglycemic effect. we evaluated the ability of an extract of green and black tea to improve glucose control over a 3-month period. a double-blind, placebo-controlled, randomized multiple-dose (0, 375, or 750 mg per day for 3 months) study in adults with type 2 diabetes mellitus not taking insulin was performed. the primary end point was change in glycosylated hemoglobin at 3 months. the 49 su ...	2007	17884442
improved sample pre-treatment for determination of caffeine in tea using a cartridge filled with polyvinylpolypyrroridone (pvpp).	we have improved sample pre-treatment for the effective removal of polyphenols and simple analysis of caffeine in tea using a cartridge filled with polyvinylpolypyrroridone (pvpp). nearly 100% of catechins were removed from the green tea sample and caffeine was completely recovered in the range of 98.2-101.3% by sample pre-treatment with a pvpp cartridge. reproducibility of preparing pvpp pre-treatment cartridges was sufficient for quantitative analysis, because rsds of analytical values for caf ...	2007	17827770
green tea and black tea consumption in relation to colorectal cancer risk: the singapore chinese health study.	the relationships between green tea and black tea consumption and colorectal cancer risk were examined within the singapore chinese health study, a prospective cohort study of diet and cancer involving >60,000 men and women. intake of green tea and black tea was assessed through in-person interviews. incident cancer cases and deaths among cohort members were identified through record linkage of the cohort database with respective databases from the nationwide singapore cancer registry and the si ...	2007	17724377
tea and coffee as the main sources of oxalate in diets of patients with kidney oxalate stones.	we analyzed nutritional habits of 22 stone formers with special regard to oxalate content as one of the main nutritional lithogenic factors associated with kidney stones. daily dietary oxalate intake was 354 +/- 261 mg and 406 +/- 265 mg in men and women respectively. these values were much higher than those found by other researches. the main sources of oxalate in diets were regular tea and coffee (80-85%). only 15-20% of oxalate was derived from other plant foods. patients did not adhere to hi ...	2007	17711092
determination of theaflavins including methylated theaflavins in black tea leaves by solid-phase extraction and hplc analysis.	a quantitative method for four theaflavins and two methylated theaflavin derivatives in black tea leaves was developed by solid-phase extraction and a high-performance liquid chromatographic method with photodiode array detection. the theaflavins in black tea leaves were extracted three times with 40 vol 50% aqueous ethanol (mg dry tea powder/ml) containing 2% ascorbic acid. the ethanol extracts were diluted 4-fold with distilled water. all diluted extracts were directly applied to the solid-pha ...	2007	17696441
food interaction of oral uptake of iron / a clinical trial using 59fe.	a primary objective of the study was to evaluate how food as well as a specific enhancer or an inhibitor of iron uptake affect erythrocyte iron uptake after oral administration of iron(iii)-hydroxide polymaltose complex (ipc, maltofer) in subjects with or without iron deficiency. secondary objectives of the study were 1. to compare the uptake of 59fe in erythrocytes between subjects with or without iron deficiency, 2. to evaluate the 59fe activity in plasma after oral administration of ipc and 3 ...	2007	17691590
tea polyphenols for health promotion.	people have been consuming brewed tea from the leaves of the camellia sinensis plant for almost 50 centuries. although health benefits have been attributed to tea, especially green tea consumption since the beginning of its history, scientific investigations of this beverage and its constituents have been underway for less than three decades. currently, tea, in the form of green or black tea, next to water, is the most widely consumed beverage in the world. in vitro and animal studies provide st ...	2007	17655876
comparative evaluation of antiproliferative, antiangiogenic and apoptosis inducing potential of black tea polyphenols in the hamster buccal pouch carcinogenesis model.	to evaluate the relative chemopreventive efficacy of two black tea polyphenols, polyphenon-b [p-b] and btf-35 on 7,12-dimethylbenz [a]anthracene (dmba)-induced hamster buccal pouch (hbp) carcinogenesis.	2007	18053169
characterization of the constituents and antioxidant activity of brazilian green tea (camellia sinensis var. assamica iac-259 cultivar) extracts.	freeze-dried extracts from camellia sinensis var. assamica iac-259 cultivar named brazilian green tea were prepared by hot water and ultrasound-assisted extractions using leaves harvested in spring and summer. their caffeine and catechin contents were measured by high performance liquid chromatography-diode array detector. the antioxidant activity of the major green tea compounds and brazilian green tea extracts was evaluated using a 2,2-diphenyl-1-picrylhydrazyl (dpph) assay. the levels of caff ...	2007	17937477
immobilised tyrosinase-based biosensor for the detection of tea polyphenols.	an amperometric principle-based biosensor containing immobilized enzyme tyrosinase has been used for detection of polyphenols in tea. the immobilized tyrosinase-based biosensor could detect tea polyphenols in the concentration range 10-80 mmol l(-1). immobilization of the enzyme by the crosslinking method gave good stable response to tea polyphenols. the biosensor response reached the steady state within 5 min. the voltage response was found to have a direct linear relationship with the concentr ...	2007	17928999
the effect of consuming instant black tea on postprandial plasma glucose and insulin concentrations in healthy humans.	to determine the effects of black tea on postprandial plasma glucose and insulin concentrations in healthy humans in response to an oral glucose load.	2007	17914136
chemical composition of green tea (camellia sinensis) infusions commercialized in portugal.	to evaluate the potential benefits and risks associated with tea consumption it is important to identify the constituents of this beverage. levels of some minerals, caffeine and catechins in green tea samples commercialized in portugal were evaluated. potassium is the metal present in larger amount (92-151 mg/l). the content of sodium, calcium, fluoride, aluminium, manganese and iron were 35-69, 1.9-3.5, 0.80-2.0, 1.0-2.2, 0.52-1.9, 0.020-0.128 mg/l, respectively. chromium and selenium were not ...	2007	17899383
a 6-month randomized pilot study of black tea and cardiovascular risk factors.	the effects of black tea consumption on cardiovascular risk factors have been inconsistent in previous randomized trials, all of which have been limited to a few weeks duration.	2007	17892999
arsenic species and leaching characters in tea (camellia sinensis).	tea is one of the most popular non-alcoholic beverages consumed in the world. arsenic including species totalling to 47 chinese tea samples from 18 tea-producing provinces in china were analyzed. by simulating the infusion process, leaching characters, effects of extraction time and temperature on arsenic extraction were investigated. total amount of arsenic in tea leaf samples was in the range below the detection limit to 4.81 microg/g. leaching of arsenic was strongly affected by extraction ti ...	2007	17892910
cadmium induced oxidative stress influence on glutathione metabolic genes of camellia sinensis (l.) o. kuntze.	glutathione, a tripeptide with sulfhydryl (-sh) group is a very crucial compound primarily involved in redox balance maintenance of the cellular environment. in this study, we monitored the influence of cd exposure on the transcript levels of glutathione metabolic genes in bud tissues, the youngest leaf, of camellia sinensis l. in addition, some physiochemical parameters were also studied. cd exposure decreased chlorophyll and protein contents, while increase was observed in lipid peroxidation u ...	2007	17607728
mixture-mixture design for the fingerprint optimization of chromatographic mobile phases and extraction solutions for camellia sinensis.	a composite simplex centroid-simplex centroid mixture design is proposed for simultaneously optimizing two mixture systems. the complementary model is formed by multiplying special cubic models for the two systems. the design was applied to the simultaneous optimization of both mobile phase chromatographic mixtures and extraction mixtures for the camellia sinensis chinese tea plant. the extraction mixtures investigated contained varying proportions of ethyl acetate, ethanol and dichloromethane w ...	2007	17605980
effects of lifestyle on urinary 1-hydroxypyrene concentration.	this study aimed to clarify the variation of urinary excretion of 1-hydroxypyrene, which is a major metabolite of pyrene, in relation to lifestyle, including factors such as diet and smoking. the study subjects were 251 workers (male: 196, female: 55, mean age: 44.3) who were not occupationally exposed to pahs. urine specimens were collected from 8:00 a.m. to 11:00 a.m. and their 1-hydroxypyrene concentrations were determined by hplc. a questionnaire was distributed in order to learn gross aspec ...	2007	17575398
polyamines in tea processing.	the distribution of dietary polyamines, putrescine, spermidine and spermine, was determined during processing of camellia sinensis. black tea manufacture is carried by a series of processes on fresh tea leaves involving withering, rolling, fermentation, drying and sieving. the aim of this research was to determine the effect of tea processing on the polyamine content in relation with antioxidant enzymes, superoxide dismutase, lipid peroxidase and glutathione peroxidase. before processing, the sp ...	2007	17566892
tea (camellia sinensis) clones with shorter periods of winter dormancy exhibit lower accumulation of reactive oxygen species.	tea (camellia sinensis (l.) o. kuntze) is a perennial crop grown throughout the world. during winter, tea undergoes a dormancy period when growth of apical buds almost ceases, severely reducing the commercial yield of tea. low temperatures prevail during the period of winter dormancy, which alone or in combination with high solar irradiance have the potential to induce oxidative stress in plants. we studied six tea clones under field conditions to test whether a relationship exists between oxida ...	2007	17545125
black tea improves endothelial function in renal transplant recipients.	endothelial damage and dysfunction are commonplace in renal transplant recipients. impaired endothelial function is an important contributor to cardiovascular diseases. we hypothesized that short-term black tea consumption may improve endothelium-dependent arterial dilation in kidney recipients.	2007	17524915
activation of endothelial nitric oxide synthase by dietary isoflavones: role of no in nrf2-mediated antioxidant gene expression.	the endothelium plays a key role in the maintenance of vascular homeostasis, and increased oxidative stress in vascular disease leads to reduced nitric oxide bioavailability and impaired endothelium-dependent relaxation of resistance vessels. although epidemiological evidence suggests that diets containing high amounts of natural antioxidants afford protection against coronary heart disease (chd), antioxidant supplementation trials have largely reported only marginal health benefits. there is co ...	2007	17498676
genetic base of tea (camellia sinensis l.) cultivars in sri lanka as revealed by pedigree analysis.	an understanding of genetic diversity and relationships among breeding materials is a prerequisite for crop improvement. coefficient of parentage (cop) can be used to measure the genetic diversity among genotypes on the basis of pedigree information. in the present study, cop was estimated for 56 cultivars, including commercial tea cultivars developed by the tea research institute of sri lanka and their parental lines. mean cop of the 56 accessions studied was 0.097 and the value was raised up t ...	2007	17495345
effects of infusion time and addition of milk on content and absorption of polyphenols from black tea.	epidemiological studies assessing the health benefits of drinking black tea are equivocal. such disparity may reflect an inability of semiquantitative assessment to consider how infusion time and addition of milk affect the bioavailability of potentially beneficial antioxidant polyphenols. six brands of tea demonstrated similar increases in antioxidant capacity and total phenolic and catechin contents with increasing infusion time. these results were unaffected by the addition of milk. consumpti ...	2007	17489604
the structure of two n-methyltransferases from the caffeine biosynthetic pathway.	caffeine (1,3,7-trimethylxanthine) is a secondary metabolite produced by certain plant species and an important component of coffee (coffea arabica and coffea canephora) and tea (camellia sinensis). here we describe the structures of two s-adenosyl-l-methionine-dependent n-methyltransferases that mediate caffeine biosynthesis in c. canephora 'robusta', xanthosine (xr) methyltransferase (xmt), and 1,7-dimethylxanthine methyltransferase (dxmt). both were cocrystallized with the demethylated cofact ...	2007	17434991
[studies on tea plants (camellia sinensis) germplasms using est-ssr marker].	forty two tea varieties were analyzed by using 16 ssr primer sets derived from tea ests in this study, and 13 of the primer sets produced clear bands and 10 of them showed polymorphism, accounting for 76.9%. the pic (polymorphism information content) for each polymorphic primer set varied from 0.522 to 0.866, with a average about 0.73. totally 84 genotypes and 74 alleles were detected in all materials by 10 polymorphic markers, with the range from 4 to 12 and from 3 to 10 for each polymorphic pr ...	2007	17284433