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Sample records for flavonoids catechins sugars

  1. Separation of (+)-catechin and quercetin on mesoporous MCM-41 composites: Dynamics of the sorption of flavonoids

    Science.gov (United States)

    Karpov, S. I.; Korabel'nikova, E. O.

    2015-06-01

    An analysis of conditions for chromatographic separation of quercetin and (+)-catechin based on experimental data and using the equations of an asymptotic model of sorption dynamics for substances characterized by convex isotherms of sorption is presented. The effects of the equilibrium (distribution coefficient) and kinetic (diffusion coefficient) factors on the dynamics of the sorption of flavonoids by ordered mesoporous material of the MCM-41 type and its composites with grafted organosilane groups is considered. The effects of kinetic and equilibrium parameters on the broadening of adsorption fronts is demonstrated with allowance for the inner and outer diffusion limitations of the sorption process.

  2. Synergistic effect of the flavonoid catechin, quercetin, or epigallocatechin gallate with fluconazole induces apoptosis in Candida tropicalis resistant to fluconazole.

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    da Silva, Cecília Rocha; de Andrade Neto, João Batista; de Sousa Campos, Rosana; Figueiredo, Narjara Silvestre; Sampaio, Letícia Serpa; Magalhães, Hemerson Iury Ferreira; Cavalcanti, Bruno Coêlho; Gaspar, Danielle Macêdo; de Andrade, Geanne Matos; Lima, Iri Sandro Pampolha; de Barros Viana, Glauce Socorro; de Moraes, Manoel Odorico; Lobo, Marina Duarte Pinto; Grangeiro, Thalles Barbosa; Nobre Júnior, Hélio Vitoriano

    2014-01-01

    Flavonoids are a class of phenolic compounds commonly found in fruits, vegetables, grains, flowers, tea, and wine. They differ in their chemical structures and characteristics. Such compounds show various biological functions and have antioxidant, antimicrobial, anti-inflammatory, and antiapoptotic properties. The aim of this study was to evaluate the in vitro interactions of flavonoids with fluconazole against Candida tropicalis strains resistant to fluconazole, investigating the mechanism of synergism. Three combinations formed by the flavonoids (+)-catechin hydrated, hydrated quercetin, and (-)-epigallocatechin gallate at a fixed concentration with fluconazole were tested. Flavonoids alone had no antifungal activity within the concentration range tested, but when they were used as a cotreatment with fluconazole, there was significant synergistic activity. From this result, we set out to evaluate the possible mechanisms of cell death involved in this synergism. Isolated flavonoids did not induce morphological changes or changes in membrane integrity in the strains tested, but when they were used as a cotreatment with fluconazole, these changes were quite significant. When evaluating mitochondrial damage and the production of reactive oxygen species (ROS) only in the cotreatment, changes were observed. Flavonoids combined with fluconazole were shown to cause a significant increase in the rate of damage and the frequency of DNA damage in the tested strains. The cotreatment also induced an increase in the externalization of phosphatidylserine, an important marker of early apoptosis. It is concluded that flavonoids, when combined with fluconazole, show activity against strains of C. tropicalis resistant to fluconazole, promoting apoptosis by exposure of phosphatidylserine in the plasma membrane and morphological changes, mitochondrial depolarization, intracellular accumulation of ROS, condensation, and DNA fragmentation.

  3. Transcriptome Analysis Reveals Key Flavonoid 3'-Hydroxylase and Flavonoid 3',5'-Hydroxylase Genes in Affecting the Ratio of Dihydroxylated to Trihydroxylated Catechins in Camellia sinensis.

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    Kang Wei

    Full Text Available The ratio of dihydroxylated to trihydroxylated catechins (RDTC is an important indicator of tea quality and biochemical marker for the study of genetic diversity. It is reported to be under genetic control but the underlying mechanism is not well understood. Flavonoid 3'-hydroxylase (F3'H and flavonoid 3',5'-hydroxylase (F3'5'H are key enzymes involved in the formation of dihydroxylated and trihydroxylated catechins. The transcriptome and HPLC analysis of tea samples from Longjing43 and Zhonghuang2 under control and shading treatment were performed to assess the F3'H and F3'5'H genes that might affect RDTC. A total of 74.7 million reads of mRNA seq (2×101bp data were generated. After de novo assembly, 109,909 unigenes were obtained, and 39,982 of them were annotated using 7 public databases. Four key F3'H and F3'5'H genes (including CsF3'5'H1, CsF3'H1, CsF3'H2 and CsF3'H3 were identified to be closely correlated with RDTC. Shading treatment had little effect on RDTC, which was attributed to the stable expression of these key F3'H and F3'5'H genes. The correlation of the coexpression of four key genes and RDTC was further confirmed among 13 tea varieties by real time PCR and HPLC analysis. The coexpression of three F3'H genes and a F3'5'H gene may play a key role in affecting RDTC in Camellia sinensis. The current results may establish valuable foundation for further research about the mechanism controlling catechin composition in tea.

  4. Pro- and Antioxidant Activity of Three Selected Flavan Type Flavonoids: Catechin, Eriodictyol and Taxifolin

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    Vladimir Chobot

    2016-11-01

    Full Text Available The flavanol (±-catechin shows an OH group but no 4-keto group on ring C (C3, and no conjugation between ring A and B. The related flavanone (+-eriodictyol has a keto group on C4 but no 3-OH group on ring C. (+-Taxifolin, another flavanone, has an OH on C3 and a keto group on C4 of the C ring. Deoxyribose degradation assay systems, with hydrogen peroxide and ascorbic acid either added or omitted, were performed in variants in which Fe(III was added in a complex with ethylenediaminetetraacetic acid (EDTA. In combination with differential pulse voltammetry (DVP, the specific redox-chemical contributions of the ring A m-dihydroxyl groups could be explored more specifically in addition to those of the traditionally investigated o-dihydroxyl groups of ring B.

  5. Positive allosteric modulation of the GHB high-affinity binding site by the GABAA receptor modulator monastrol and the flavonoid catechin.

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    Eghorn, Laura F; Hoestgaard-Jensen, Kirsten; Kongstad, Kenneth T; Bay, Tina; Higgins, David; Frølund, Bente; Wellendorph, Petrine

    2014-10-05

    γ-Hydroxybutyric acid (GHB) is a metabolite of γ-aminobutyric acid (GABA) and a proposed neurotransmitter in the mammalian brain. We recently identified α4βδ GABAA receptors as possible high-affinity GHB targets. GABAA receptors are highly sensitive to allosteric modulation. Thus to investigate whether GHB high-affinity binding sites are also sensitive to allosteric modulation, we screened both known GABAA receptor ligands and a library of natural compounds in the rat cortical membrane GHB specific high-affinity [3H]NCS-382 binding assay. Two hits were identified: Monastrol, a positive allosteric modulator of GABA function at δ-containing GABAA receptors, and the naturally occurring flavonoid catechin. These compounds increased [3H]NCS-382 binding to 185-272% in high micromolar concentrations. Monastrol and (+)-catechin significantly reduced [3H]NCS-382 dissociation rates and induced conformational changes in the binding site, demonstrating a positive allosteric modulation of radioligand binding. Surprisingly, binding of [3H]GHB and the GHB high-affinity site-specific radioligands [125I]BnOPh-GHB and [3H]HOCPCA was either decreased or only weakly increased, indicating that the observed modulation was critically probe-dependent. Both monastrol and (+)-catechin were agonists at recombinant α4β3δ receptors expressed in Xenopus laevis oocytes. When monastrol and GHB were co-applied no changes were seen compared to the individual responses. In summary, we have identified the compounds monastrol and catechin as the first allosteric modulators of GHB high-affinity binding sites. Despite their relatively weak affinity, these compounds may aid in further characterization of the GHB high-affinity sites that are likely to represent certain GABAA receptors.

  6. Effect of Chlorocholine Chloride on Chlorophyll, Photosynthesis, Soluble Sugar and Flavonoids of Ginkgo biloba

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    Weiwei ZHANG

    2013-05-01

    Full Text Available The flavonoids content determines the quality characteristics of Ginkgo biloba extract that could be increased by using of plant growth regulators. The objective of study was to investigate the effect of chlorocholine chloride (CCC, an anti-gibberellin growth retardant, on photosynthesis, chlorophyll, soluble sugar, total amino acids and phenylalanine contents, flavonoid accumulation, and flavonoids enzyme activity in G. biloba leaves. The ginkgo seedlings were grown in the greenhouse conditions with foliar applications of 0 (control, 0.5, 1.0 and 2.0 g l-1 CCC. Results showed that 0.5, 1.0 and 2.0 g l-1 CCC treatments significantly increased photosynthetic rates of leaves, the contents of chlorophyll, soluble sugar, total amino acids and phenylalnine in ginkgo leaves. Total polyphenols, flavonoids, anthocyanins content, phenylalanine ammonia-lyase (PAL, chalcone synthase (CHS and chalcone isomerase (CHI activities were all significantly increased by 1.0 and 2.0 g l-1 CCC treatments. Foliar treatment with CCC therefore might be a useful means of improving pharmacological properties of G. biloba leaves.

  7. Identification of catechin as one of the flavonoids from Combretum albiflorum bark extract that reduces the production of quorum-sensing-controlled virulence factors in Pseudomonas aeruginosa PAO1.

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    Vandeputte, Olivier M; Kiendrebeogo, Martin; Rajaonson, Sanda; Diallo, Billo; Mol, Adeline; El Jaziri, Mondher; Baucher, Marie

    2010-01-01

    Quorum-sensing (QS) regulates the production of key virulence factors in Pseudomonas aeruginosa and other important pathogenic bacteria. In this report, extracts of leaves and bark of Combretum albiflorum (Tul.) Jongkind (Combretaceae) were found to quench the production of QS-dependent factors in P. aeruginosa PAO1. Chromatographic fractionation of the crude active extract generated several active fractions containing flavonoids, as shown by their typical spectral features. Purification and structural characterization of one of the active compounds led to the identification of the flavan-3-ol catechin [(2R,3S)-2-(3,4-dihydroxyphenyl)-3,4-dihydro-1(2H)-benzopyran-3,5,7-triol]. The identity of catechin as one of the active molecules was confirmed by comparing the high-pressure liquid chromatography profiles and the mass spectrometry spectra obtained for a catechin standard and for the active C. albiflorum fraction. Moreover, standard catechin had a significant negative effect on pyocyanin and elastase productions and biofilm formation, as well as on the expression of the QS-regulated genes lasB and rhlA and of the key QS regulatory genes lasI, lasR, rhlI, and rhlR. The use of RhlR- and LasR-based biosensors indicated that catechin might interfere with the perception of the QS signal N-butanoyl-l-homoserine lactone by RhlR, thereby leading to a reduction of the production of QS factors. Hence, catechin, along with other flavonoids produced by higher plants, might constitute a first line of defense against pathogenic attacks by affecting QS mechanisms and thereby virulence factor production.

  8. Temperature-dependent studies on the total phenolics, flavonoids, antioxidant activities, and sugar content in six onion varieties

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    Kavita Sharma

    2015-06-01

    Full Text Available Heating effect on total phenol, flavonoids, antioxidant activity, and sugar content of six onion varieties has been quantitatively investigated to explore the effect of different temperatures. The onion varieties comprised one red-skinned variety, two white-skinned varieties, and three yellow-skinned varieties. The heating temperature was scanned at 80°C, 100°C, 120°C, and 150°C for 30 minutes each, and quantitative analysis was performed relative to the powdered onion at ambient temperature. Quercetin, glucosides and sugar content were analyzed using high-performance liquid chromatography. The total phenolic and antioxidant content increased in all six varieties. The total flavonoid levels showed a considerable change. On heating the onion samples at 120°C for 30 minutes, the red-skinned variety showed the highest level of total phenolic content [13712.67 ± 1034.85 μg of gallic acid equivalent/g dry weight (μg GAE/g DW] and total flavonoids [3456.00 ± 185.82 μg of quercetin equivalents/g dry weight (μg Q/g DW], whereas the content of total phenolics and total flavonoids were 13611.83 ± 341.61 μg GAE/g DW and 3482.87 ± 117.17 μg Q/g DW, respectively, for the yellow-skinned (Sunpower variety. Quercetin and its glucoside contents increased up to 120°C and then decreased at 150°C, whereas the sugar content continuously decreased with heating. All cultivars showed the same pattern in the heating effect, and the predominant flavonoids were destroyed at higher temperatures. Therefore, it is improper to expose onion powder to a temperature higher than 120°C.

  9. Quantitative analysis of flavonoids, sugars, phenylalanine and tryptophan in onion scales during storage under ambient conditions.

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    Sharma, Kavita; Assefa, Awraris D; Ko, Eun Young; Lee, Eul Tai; Park, Se Won

    2015-04-01

    A comprehensive quantitative analysis of flavonoids, sugars, phenylalanine, and tryptophan have been carried out in different onion scales during storage at ambient temperature (20-23 °C) and relative humidity (60-80 %). Depending on the length of storage, dry matter content and composition shows variation inside the onion bulbs. Inner sprouts were observed on longitudinally cut bulbs after 2 months and visible sprouts appeared after 5 months of storage. The bulbs lost 20 to 30 % of their weight at the end of the storage. Higher dry matter content was observed in the inner scales. Significantly high content of quercetin in inner scales and high level of quercetin-3,4'-O-diglucoside and quercetin-4'-O-monoglucoside in outer scales was observed during a 7 months storage. During storage period, high content of fructose and glucose was observed in the middle scales while sucrose was high in the inner scales. There was no particular trend observed within analyzed amino acids. However, the content of phenylalanine was higher than tryptophan.

  10. Interactions of catechins with copper ions

    OpenAIRE

    Řihošková, Petra

    2014-01-01

    Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical botanic and ecology Candidate: Mgr. Petra Řihošková Supervisor: PharmDr. Jana Karlíčková, Ph.D. Title of Thesis: Interactions of catechins with copper ions Keywords: catechins, chelating activity, copper, bathocuproine, hematoxylin, antioxidants Flavonoids are a class of plant polyphenols with significant antioxidant activity, which positively affects human health. Flavonoids are able to chelate me...

  11. Dynamic changes in catechin levels and catechin biosynthesis-related gene expression in albino tea plants (Camellia sinensis L.).

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    Xiong, Ligui; Li, Juan; Li, Yinhua; Yuan, Ling; Liu, Shuoqian; Huang, Jian'an; Liu, Zhonghua

    2013-10-01

    Tea (Camellia sinensis (L.) O. Kuntze) leaves are a major source of flavonoids that mainly belong to the flavan-3-ols or catechins and are implicated in a wide range of health benefits. Although the catechins in tea leaves were identified long ago, the regulatory mechanisms governing catechin biosynthesis remain unclear. In the present work, the dynamic changes of catechin levels and the expression profiles of catechin-related genes in albino tea plants were intensively examined. The amounts of most catechins decreased to their lowest levels in the albino phase, when epigallocatechingallate was the highest of the catechins compared to all catechins, and catechin the lowest. Enzyme assays indicated that phenylalanine ammonia-lyase (PAL) activity was positively correlated with the concentration of catechins (r = 0.673). Gene expression profiling by quantitative real-time reverse transcription-polymerase chain reaction showed that the transcript abundance of flavonoid biosynthetic genes followed a tightly regulated biphasic pattern, and was affected by albinism. These genes (PAL, C4H, 4CL, CHS, CHI, F3H, FLS, F3'H, F3'5'H, DFR, LAR, ANS and ANR) encode enzymes in flavonoid biosynthesis. The expression levels of PAL, F3H and FLS were correlated with the concentration of catechins and the correlation coefficients were -0.683, 0.687 and -0.602, respectively. Therefore, these results indicate that PAL might be a core regulator in the control of catechin biosynthesis in albino tea plants.

  12. Catechin intake and associated dietary and lifestyle factors in a representative sample of Dutch men and women

    NARCIS (Netherlands)

    Arts, I.C.W.; Hollman, P.C.H.; Feskens, E.J.M.; Bueno de Mesquita, H.B.; Kromhout, D.

    2001-01-01

    To study the intake of catechins in the Dutch population and to assess the relation between catechin intake and other dietary factors. Catechins, dietary components that belong to the flavonoid family, potentially protect against chronic diseases such as cancer and cardiovascular diseases. Catechins

  13. Characterization of the endogenous enzymatic hydrolyses of Petroselinum crispum glycosides: determined by chromatography upon their sugar and flavonoid products.

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    Boldizsár, Imre; Füzfai, Zsófia; Molnár-Perl, Ibolya

    2013-06-07

    The behavior of the flavonoid diglycosides, relevant constituents of parsley (Petroselinum crispum) fruit (PFr) and leaf (PLe) samples was characterized upon their enzymatic hydrolyses applying complementary liquid chromatography-ultraviolet (LC-UV) and gas chromatography mass selective (GC-MS) detections. Analyses were performed in quantitative manner, from the same extracts as a function of hydrolysis times. Both in fruit and leaf tissue extracts, in intact and in enzyme hydrolyzed ones, apigenin, chrysoeriol, their glycosides, sugars, sugar alcohols, carboxylic acids and phytosterols, in total 17 constituents were identified and quantified. Based primarily on the selective mass fragmentation properties of the trimethylsilyl (oxime) ether/ester derivatives of constituents, we confirmed several novelties to the field. (i) It was shown for the first time that in parsley tissues different types of glycosidase enzyme are active. In PFr samples, both the stepwise and disaccharide specific endogenous mechanisms were certified, quantifying simultaneously the continuous release of apigenin, chrysoeriol, 2-O-apiosyl-apiose, apiose and glucose. (ii) 2-O-Apiosyl-glucose was demonstrated as disaccharide due to its formation under derivatization conditions from parsley glycosides. (iii) Both in PFr and in PLe samples even the invertase enzyme activity was attainable: sucrose decomposition in both tissues was going on with the same intensity. Three different types of enzymatic glycosidase processes were followed with their specific hydrolysis products by means of HPLC-UV and GC-MS, simultaneously.

  14. Dietary catechins and cancer incidence among postmenopausal women: the Iowa Women's Health Study (US)

    NARCIS (Netherlands)

    Arts, I.C.W.; Jacobs Jr., D.R.; Gross, M.; Harnack, L.J.; Folsom, A.R.

    2002-01-01

    Catechins are bioactive flavonoids present in tea, fruits, and vegetables. Previous epidemiological studies regarding tea and cancer risk were inconclusive, possibly because catechins are also present in other plant foods. We investigated whether a high intake of catechins are associated with cancer

  15. Dietary catechins and epithelial cancer incidence: the Zutphen elderly study

    NARCIS (Netherlands)

    Arts, I.C.W.; Hollman, P.C.H.; Bueno de Mesquita, H.B.; Feskens, E.J.M.; Kromhout, D.

    2001-01-01

    The flavonoids, a group of more than 4,000 polyphenolic antioxidants, are potential cancer preventive components of fruits and vegetables. Catechins, one of the 6 major groups of flavonoids, are present in high concentrations in tea as well. Our objective was to evaluate the association between inta

  16. Flavonoids: prospective drug candidates.

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    Cazarolli, Luisa Helena; Zanatta, Leila; Alberton, Elga Heloisa; Figueiredo, Maria Santos Reis Bonorino; Folador, Poliane; Damazio, Rosangela Guollo; Pizzolatti, Moacir Geraldo; Silva, Fátima Regina Mena Barreto

    2008-11-01

    The purpose of this review is to discuss the recent developments related to the chemistry and medicinal properties of flavonoids. Major flavonoids that show well categorized structures and well defined structure function-relationships are: flavans, flavanones, flavones, flavanonols, flavonols, catechins, anthocyanidins and isoflavone. The biological properties of flavonoids include antioxidant, anti-inflamatory, antitumoral, antiviral and antibacterial, as well as a direct cytoprotective effect on coronary and vascular systems, the pancreas and the liver. These characteristics place them among the most attractive natural substances available to enrich the current therapy options.

  17. Different Flavonoids Can Shape Unique Gut Microbiota Profile In Vitro.

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    Huang, Jiacheng; Chen, Long; Xue, Bin; Liu, Qianyue; Ou, Shiyi; Wang, Yong; Peng, Xichun

    2016-09-01

    The impact of flavonoids has been discussed on the relative viability of bacterial groups in human microbiota. This study was aimed to compare the modulation of various flavonoids, including quercetin, catechin and puerarin, on gut microbiota culture in vitro, and analyze the interactions between bacterial species using fructo-oligosaccharide (FOS) as carbon source under the stress of flavonoids. Three plant flavonoids, quercetin, catechin, and puerarin, were added into multispecies culture to ferment for 24 h, respectively. The bacterial 16S rDNA amplicons were sequenced, and the composition of microbiota community was analyzed. The results revealed that the tested flavonoids, quercetin, catechin, and puerarin, presented different activities of regulating gut microbiota; flavonoid aglycones, but not glycosides, may inhibit growth of certain species. Quercetin and catechin shaped unique biological webs. Bifidobacterium spp. was the center of the biological web constructed in this study.

  18. Dietary catechins and their potentially protective role in cardiovascular diseases and cancer

    NARCIS (Netherlands)

    Arts, I.

    2001-01-01

    Catechins are polyphenolic compounds in plant foods that belong to the family of flavonoids. Due to their strong antioxidant activity and their capacity to influence mammalian enzyme systems, catechins were hypothesized to affect risk of cardiovascular diseases and cancer in humans. After optimizing

  19. Dietary catechins in relation to coronary heart disease death among postmenopausal women

    NARCIS (Netherlands)

    Arts, I.C.W.; Jacobs, D.R.; Harnack, L.J.; Gross, M.; Folsom, A.R.

    2001-01-01

    Catechins, one of the major groups of flavonoids, are bioactive compounds present in a variety of plant foods and beverages. Experimental data suggest that they might prevent chronic diseases in humans. We studied whether the intake of catechins was inversely associated with the risk of coronary

  20. Dietary catechins in relation to coronary heart disease death among postmenopausal women

    NARCIS (Netherlands)

    Arts, I.C.W.; Jacobs, D.R.; Harnack, L.J.; Gross, M.; Folsom, A.R.

    2001-01-01

    Catechins, one of the major groups of flavonoids, are bioactive compounds present in a variety of plant foods and beverages. Experimental data suggest that they might prevent chronic diseases in humans. We studied whether the intake of catechins was inversely associated with the risk of coronary hea

  1. Dietary catechins and their potentially protective role in cardiovascular diseases and cancer

    NARCIS (Netherlands)

    Arts, I.C.W.

    2001-01-01

    Catechins are polyphenolic compounds in plant foods that belong to the family of flavonoids. Due to their strong antioxidant activity and their capacity to influence mammalian enzyme systems, catechins were hypothesized to affect risk of cardiovascular diseases and cancer in humans. After

  2. Green tea catechins: defensive role in cardiovascular disorders

    Institute of Scientific and Technical Information of China (English)

    Pooja Bhardwaj; Deepa Khanna

    2013-01-01

    Green tea,Camellia sinensis (Theaeeae),a major source of flavonoids such as catechins,has recently shown multiple cardiovascular health benefits through various experimental and clinical studies.These studies suggest that green tea catechins prevent the incidence of detrimental cardiovascular events,and also lower the cardiovascular mortality rate.Catechins present in green tea have the ability to prevent atherosclerosis,hypertension,endothelial dysfunction,ischemic heart diseases,cardiomyopathy,cardiac hypertrophy and congestive heart failure by decreasing oxidative stress,preventing inflammatory events,reducing platelet aggregation and halting the proliferation of vascular smooth muscle cells.Catechins afford an anti-oxidant effect by inducing anti-oxidant enzymes,inhibiting pro-oxidant enzymes and scavenging free radicals.Catechins present anti-inflammatory activity through the inhibition of transcriptional factor NF-κB-mediated production of cytokines and adhesion molecules.Green tea catechins interfere with vascular growth factors and thus inhibit vascular smooth muscle cell proliferation,and also inhibit thrombogenesis by suppressing platelet adhesion.Additionally,catechins could protect vascular endothelial cells and enhance vascular integrity and regulate blood pressure.In this review various experimental and clinical studies suggesting the role of green tea catechins against the markers of cardiovascular disorders and the underlying mechanisms for these actions are discussed.

  3. Reviews of Salicylic Acid Mist Spray on Amount of Flavonoids, Anthocyanins, Sugar and Root Performance at Marigold Flower Species (Calendula Officinalis L at Hydroponics System

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    Fatemeh Naghavi

    2016-03-01

    Full Text Available This research is performed in order of studying anti-stress effect of salicylic acid material on Calendula Officinalis L after germinating. Different Concentrations of salicylic acid ( 2,4,+ and 8 milimolar on Seedlings of Calendula Officinalis L flower Hydroponic and greenhouse conditions during 4 days was studied. Between concentration of mist sprayed salicylic acid, 6 molar concentration had the best effect on Qualitative and quantitative performance of mentioned plant. Reviews indicate that high concntrations cause stop in growth of plant and Destruction of plant and also low concentrations had no particular effect. Results from measuring Flavonoids, anthocyanins and root performance showed that their rate after 24 hours in comparison to Control plants, indicates a meaningful increase. On treating salicylic acid there was a meaningful decrease on Germination of treated plants in comparison to control group was observed. Overally, salicylic acid at 6 molar concentration results in increase of Flavonoids, root, anthocyanins and Soluble sugars in comparison to control group.

  4. 紫芽茶树类黄酮生物合成关键酶基因表达与总儿茶素、花青素含量相关性分析%Correlation Analysis between Total Catechins (or Anthocyanins) and Expres-sion Levels of Genes Involved in Flavonoids Biosynthesis in Tea Plant with Purple Leaf

    Institute of Scientific and Technical Information of China (English)

    周天山; 王新超; 余有本; 肖瑶; 钱文俊; 肖斌; 杨亚军

    2016-01-01

    Flavan-3-ols (aka catechins) and Anthocyanins found in large amounts in tea plant with purple leaf are synthesized through flavonoids metobolic pathway. To investigate the metobolic flux of flavanoids biosynthetic pathway in tea plant with pur-ple leaf, we employed a tea plant with purple leaf and a tea plant with green leaf both from Mei-Tan-Tai-Cha, to examine the ex-pression profiles of related genes involved in flavonoids biosynthesis intensively and determine the concentrations of catechins and anthocynins. The correlation between total catechins (or anthocyanin) and the expression levels of related genes were ana-lyzed. The results indicated that the expression levels of related genes (PAL, CHS, CHI, F3H, DFR, ANS, ANR1, ANR2, F3’H, and F3’5’H) were up-regulated in purple leaves as compared with those in the green leaves. The purple leaf also had higher concentra-tion of anthocyanins than the green leaf, while the green leaf was richer in total catechins. In purple leaves, the expression levels of related genes (except LAR) were highly correlated with both concentrations of total catechins (r=0.84–0.99) and anthocyanins (r = 0.72–1.00). In contrast, there was only a high correlation between the expression levels of related genes (except LAR and F3’H) and the concentration of total catechines (r=0.64–0.77) in green leaves.%儿茶素类化合物与花青素均由类黄酮代谢途径合成,紫芽茶中富含花青素。为探明紫芽茶树中类黄酮生物合成代谢流的情况,本试验以来源于湄潭苔茶后代的1株紫色芽叶茶树和1株绿色芽叶茶树为材料,测定芽下第一叶、第二叶和第三叶的叶色、儿茶素类组分和花青素总量,分析了类黄酮生物合成相关的基因表达情况及基因表达量同总儿茶素、花青素累积量之间的相关性。结果表明,紫芽茶树中各叶位中花青素含量均显著高于对照绿芽茶树,而儿茶素类总量却低于对照;类黄

  5. Antioxidant Activity and α-Glucosidase Inhibitory Activities of the Polycondensate of Catechin with Glyoxylic Acid.

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    Sheng Geng

    Full Text Available In order to investigate polymeric flavonoids, the polycondensate of catechin with glyoxylic acid (PCG was prepared and its chemically antioxidant, cellular antioxidant (CAA and α-glucosidase inhibitory activities were evaluated. The DPPH and ABTS radical scavenging activities and antiproliferative effect of PCG were lower than those of catechin, while PCG had higher CAA activity than catechin. In addition, PCG had very high α-glucosidase inhibitory activities (IC50 value, 2.59 μg/mL in comparison to catechin (IC50 value, 239.27 μg/mL. Inhibition kinetics suggested that both PCG and catechin demonstrated a mixture of noncompetitive and anticompetitive inhibition. The enhanced CAA and α-glucosidase inhibitor activities of PCG could be due to catechin polymerization enhancing the binding capacity to the cellular membrane and enzymes.

  6. Effect of Tea Theaflavins and Catechins on Microvascular Function

    Science.gov (United States)

    Fuchs, Dagmar; de Graaf, Young; van Kerckhoven, Roeland; Draijer, Richard

    2014-01-01

    Beneficial effects of flavonoid-rich black and green tea on macrocirculation have been well established. Theaflavins are unique to black tea as they are formed from catechins during the enzymatic oxidation of tea leaves. The study was performed to gain more insight into the effects of theaflavins on microcirculation and to compare effects with another important flavonoid class, the green tea derived catechins, which have been reported to improve vascular function. Twenty-four healthy subjects were included in a double-blind, placebo-controlled, randomised, cross-over study. On six different days, subjects received capsules with a single dose of catechins (500 mg), four varying doses of theaflavins (100 to 500 mg) or placebo. Microcirculation was assessed after each treatment by Pulse Amplitude Tonometry (EndoPAT) at baseline and 2, 4 and 6 h after test product intake. The EndoPAT reactive hyperemia response was improved by 500 mg catechins (reactive hyperemia index (RHI): 0.2; p = 0.04) and by 500 mg theaflavins (RHI: 0.19; p = 0.06) compared to placebo. Also, 300 mg theaflavins increased the RHI (0.28; p = 0.02), but no effects were observed at lower doses. The study suggests moderate effects of single doses of catechins and theaflavins on peripheral microcirculation. PMID:25514559

  7. Effect of Tea Theaflavins and Catechins on Microvascular Function

    Directory of Open Access Journals (Sweden)

    Dagmar Fuchs

    2014-12-01

    Full Text Available Beneficial effects of flavonoid-rich black and green tea on macrocirculation have been well established. Theaflavins are unique to black tea as they are formed from catechins during the enzymatic oxidation of tea leaves. The study was performed to gain more insight into the effects of theaflavins on microcirculation and to compare effects with another important flavonoid class, the green tea derived catechins, which have been reported to improve vascular function. Twenty-four healthy subjects were included in a double-blind, placebo-controlled, randomised, cross-over study. On six different days, subjects received capsules with a single dose of catechins (500 mg, four varying doses of theaflavins (100 to 500 mg or placebo. Microcirculation was assessed after each treatment by Pulse Amplitude Tonometry (EndoPAT at baseline and 2, 4 and 6 h after test product intake. The EndoPAT reactive hyperemia response was improved by 500 mg catechins (reactive hyperemia index (RHI: 0.2; p = 0.04 and by 500 mg theaflavins (RHI: 0.19; p = 0.06 compared to placebo. Also, 300 mg theaflavins increased the RHI (0.28; p = 0.02, but no effects were observed at lower doses. The study suggests moderate effects of single doses of catechins and theaflavins on peripheral microcirculation.

  8. Effect of tea theaflavins and catechins on microvascular function.

    Science.gov (United States)

    Fuchs, Dagmar; de Graaf, Young; van Kerckhoven, Roeland; Draijer, Richard

    2014-12-11

    Beneficial effects of flavonoid-rich black and green tea on macrocirculation have been well established. Theaflavins are unique to black tea as they are formed from catechins during the enzymatic oxidation of tea leaves. The study was performed to gain more insight into the effects of theaflavins on microcirculation and to compare effects with another important flavonoid class, the green tea derived catechins, which have been reported to improve vascular function. Twenty-four healthy subjects were included in a double-blind, placebo-controlled, randomised, cross-over study. On six different days, subjects received capsules with a single dose of catechins (500 mg), four varying doses of theaflavins (100 to 500 mg) or placebo. Microcirculation was assessed after each treatment by Pulse Amplitude Tonometry (EndoPAT) at baseline and 2, 4 and 6 h after test product intake. The EndoPAT reactive hyperemia response was improved by 500 mg catechins (reactive hyperemia index (RHI): 0.2; p = 0.04) and by 500 mg theaflavins (RHI: 0.19; p = 0.06) compared to placebo. Also, 300 mg theaflavins increased the RHI (0.28; p = 0.02), but no effects were observed at lower doses. The study suggests moderate effects of single doses of catechins and theaflavins on peripheral microcirculation.

  9. Quantification of the predominant monomeric catechins in baking chocolate standard reference material by LC/APCI-MS.

    Science.gov (United States)

    Nelson, Bryant C; Sharpless, Katherine E

    2003-01-29

    Catechins are polyphenolic plant compounds (flavonoids) that may offer significant health benefits to humans. These benefits stem largely from their anticarcinogenic, antioxidant, and antimutagenic properties. Recent epidemiological studies suggest that the consumption of flavonoid-containing foods is associated with reduced risk of cardiovascular disease. Chocolate is a natural cocoa bean-based product that reportedly contains high levels of monomeric, oligomeric, and polymeric catechins. We have applied solid-liquid extraction and liquid chromatography coupled with atmospheric pressure chemical ionization-mass spectrometry to the identification and determination of the predominant monomeric catechins, (+)-catechin and (-)-epicatechin, in a baking chocolate Standard Reference Material (NIST Standard Reference Material 2384). (+)-Catechin and (-)-epicatechin are detected and quantified in chocolate extracts on the basis of selected-ion monitoring of their protonated [M + H](+) molecular ions. Tryptophan methyl ester is used as an internal standard. The developed method has the capacity to accurately quantify as little as 0.1 microg/mL (0.01 mg of catechin/g of chocolate) of either catechin in chocolate extracts, and the method has additionally been used to certify (+)-catechin and (-)-epicatechin levels in the baking chocolate Standard Reference Material. This is the first reported use of liquid chromatography/mass spectrometry for the quantitative determination of monomeric catechins in chocolate and the only report certifying monomeric catechin levels in a food-based Standard Reference Material.

  10. Development of CAPS markers to identify Indian tea (Camellia sinensis) clones with high catechin content.

    Science.gov (United States)

    Elangbam, M; Misra, A K

    2016-06-10

    Tea leaves are rich in plant secondary phenolics, especially flavonoids. Catechins are considered to be the most valuable flavonoids, and the catechin content in tea is an important trait for determining its quality. We have developed cleaved amplified polymorphic sequence (CAPS)-based markers for evaluating total catechin content that target two important secondary metabolite pathway genes, PAL (phenylalanine ammonia-lyase) and CHS (chalcone synthase). Catechin content levels in the tea samples tested ranged from 9 to 33 mg/mg. The CAPS technique identified clones with the homozygous profile PRc1, which has relatively lower catechin content than clones with the heterozygous profile PRc2. A significant difference (t = 16.85) in the level of catechin content was also detected between heterozygotes and homozygotes in the tea seed stock TS379. We found a polynomial relationship between the marker developed for CHS2 and catechin content in these tea samples with R2 = 0.9788. Moreover, PAL has less of a relationship with catechin content. Therefore, we recommend tea clones with heterozygous CAPS profiles for the gene CHS2+RcaI for the further improvement in these clones.

  11. Antioxidant Effects of Quercetin and Catechin Encapsulated into PLGA Nanoparticles

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    Hector Pool

    2012-01-01

    Full Text Available Polymeric nanoparticles (PLGA have been developed for the encapsulation and controlled release of quercetin and catechin. Nanoparticles were fabricated using a solvent displacement method. Physicochemical properties were measured by light scattering, scanning electron microscopy and ζ-potential, X-ray diffraction, infrared spectroscopy and differential scanning calorimetry. Encapsulation efficiency and in vitro release profiles were obtained from differential pulse voltammetry experiments. Antioxidant properties of free and encapsulated flavonoids were determined by TBARS, fluorescence spectroscopy and standard chelating activity methods. Relatively small (d≈ 400 nm polymeric nanoparticles were obtained containing quercetin or catechin in a non-crystalline form (EE ≈ 79% and the main interactions between the polymer and each flavonoid were found to consist of hydrogen bonds. In vitro release profiles were pH-dependant, the more acidic pH, the faster release of each flavonoid from the polymeric nanoparticles. The inhibition of the action of free radicals and chelating properties, were also enhanced when quercetin and catechin were encapsulated within PLGA nanoparticles. The information obtained from this study will facilitate the design and fabrication of polymeric nanoparticles as possible oral delivery systems for encapsulation, protection and controlled release of flavonoids aimed to prevent oxidative stress in human body or food products.

  12. Quantification of Tea Flavonoids by High Performance Liquid Chromatography

    Science.gov (United States)

    Freeman, Jessica D.; Niemeyer, Emily D.

    2008-01-01

    We have developed a laboratory experiment that uses high performance liquid chromatography (HPLC) to quantify flavonoid levels in a variety of commercial teas. Specifically, this experiment analyzes a group of flavonoids known as catechins, plant-derived polyphenolic compounds commonly found in many foods and beverages, including green and black…

  13. Antiartherosclerotic Effects of Plant Flavonoids

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    Shamala Salvamani

    2014-01-01

    Full Text Available Atherosclerosis is the process of hardening and narrowing the arteries. Atherosclerosis is generally associated with cardiovascular diseases such as strokes, heart attacks, and peripheral vascular diseases. Since the usage of the synthetic drug, statins, leads to various side effects, the plants flavonoids with antiartherosclerotic activity gained much attention and were proven to reduce the risk of atherosclerosis in vitro and in vivo based on different animal models. The flavonoids compounds also exhibit lipid lowering effects and anti-inflammatory and antiatherogenic properties. The future development of flavonoids-based drugs is believed to provide significant effects on atherosclerosis and its related diseases. This paper discusses the antiatherosclerotic effects of selected plant flavonoids such as quercetin, kaempferol, myricetin, rutin, naringenin, catechin, fisetin, and gossypetin.

  14. Anti-influenza Virus Effects of Catechins: A Molecular and Clinical Review.

    Science.gov (United States)

    Ide, Kazuke; Kawasaki, Yohei; Kawakami, Koji; Yamada, Hiroshi

    2016-01-01

    Influenza infection and associated epidemics represent a serious public health problem. Several preventive and curative measures exist against its spread including vaccination and therapeutic agents such as neuraminidase inhibitors (e.g., oseltamivir, zanamivir, as well as peramivir and laninamivir, which are licensed in several countries) and adamantanes (e.g., amantadine and rimantadine). However, neuraminidase inhibitor- and adamantane- resistant viruses have been detected, whereas vaccines exhibit strain-specific effects and are limited in supply. Thus, new approaches are needed to prevent and treat influenza infections. Catechins, a class of polyphenolic flavonoids present in tea leaves, have been reported as potential anti-influenza virus agents based on experimental and clinical studies. (-)-epigallocatechin gallate (EGCG), a major and highly bioactive catechin, is known to inhibit influenza A and B virus infections in Madin-Darby canine kidney cells. Additionally, EGCG and other catechin compounds such as epicatechin gallate and catechin-5-gallate also show neuraminidase inhibitory activities as demonstrated via molecular docking. These catechins can bind differently to neuraminidase and might overcome known drug resistancerelated virus mutations. Furthermore, the antiviral effects of chemically modified catechin derivatives have also been investigated, and future structure-based drug design studies of catechin derivatives might contribute to improvements in influenza prevention and treatment. This review briefly summarizes probable mechanisms underlying the inhibitory effects of tea catechins against influenza infection and their clinical benefits on influenza prevention and treatment. Additionally, the great potential of tea catechins and their chemical derivatives as effective antiviral agents is described.

  15. Effect of green tea catechins on breast carcinogenesis: a systematic review of in-vitro and in-vivo experimental studies.

    Science.gov (United States)

    Yiannakopoulou, Eugenia Ch

    2014-03-01

    Catechins (flavan-3-oils) are the main flavonoids present in green tea. The potential cancer chemopreventive and therapeutic properties of green tea catechins have been the focus of research efforts in the last two decades. This systematic review aims to generate in vitro and in vivo data on the effect of green tea catechins on breast carcinogenesis. Electronic databases were searched with the appropriate search terms. Existing evidence suggests that green tea catechins modulate breast cell carcinogenesis. The effect of green tea catechins on breast cell carcinogenesis has been investigated in different experimental models and under different experimental conditions, that is, carcinogen investigated, green tea catechin dosage regimen, treatment with green tea extract versus pure synthetic EGCG, and time point of treatment with green tea catechins in relation to the exposure to the carcinogen. Although the effect of green tea catechins was not always statistically significant, the protective effect of green tea catechins was demonstrated in all the trials, suggesting that treatment with green tea catechins should be further investigated in the clinical setting of chemoprevention of high-risk women. However, it should be emphasized that the reported actions of green tea catechins are observed in high concentrations that are difficult to achieve in the clinical setting. This drawback could be overcome by designing green tea catechins with better bioavailability and/or by cotreatment combining breast cancer endocrine treatment with green tea catechins.

  16. Catechins and Procyanidins of Ginkgo biloba Show Potent Activities towards the Inhibition of β-Amyloid Peptide Aggregation and Destabilization of Preformed Fibrils

    OpenAIRE

    Haiyan Xie; Jing-Rong Wang; Lee-Fong Yau; Yong Liu; Liang Liu; Quan-Bin Han; Zhongzhen Zhao; Zhi-Hong Jiang

    2014-01-01

    Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761). In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds, six of them were identified as (+)-catechin, (−)-epicatechin, (−)-gallocatechin, (−)-epigallocatechin and procyanidins B1 and B3. The acti...

  17. Influence of Tea Catechins on Lipid Metabolism

    OpenAIRE

    Ikeda, Ikuo

    2006-01-01

    Tea catechins reduce serum cholesterol concentration and suppress postprandial hypertriacylglycerolemia in experimental animals and humans. These effects are mainly ascribed to gallate esters of catechins, (-)-epicatechin gallate (ECG) and (-)-epigallocatechin gallate (EGCG). During heat treatment for pasteurization, tea catechins are epimerized to so-called heat-treated tea catechins such as (-)-catechin gallate (CG) and (-)-gallocatechin gallate (GCG). We showed that both tea catechins and ...

  18. A History of Catechin Chemistry with Special Reference to Tea Leaves

    Science.gov (United States)

    Ryoyasu, Saijo; Katoh, Miyuki

    This review describes the history of the discovery of catechins, i.e., flavan 3-ols in the flavonoid compounds, with a special reference to tea leaves. 1. Catechin was first separated from gambier catechu and acacia catechu, and its molecular weight and chemical structure were proposed in 1902. By 1948 the six catechins,(+)-catechin,(-)-epicatechin,(-)-epicatechin 3-O-gallate,(-)-epigallocatechin,(+)-gallocatechin, and(-)-epigallocatechin 3-O-gallate, as shown in Table 1, had been found in a variety of plants, including tea. Table 1 summarizes each catechin, the plant associated with it, and the year and authorship of each first reporting.(-)-Epigallocatechin 3-gallate was isolated from tea leaves in 1948 as the last compound of the six catechins, even though it accounted for the largest proportion of total catechin content. The compound was not isolated and purified by traditional separation methods, such as the ethyl acetate extraction and lead acetate precipitation methods; instead, silica gel column chromatography was the key technique used to succeed in the separation and purification of the compound, from which the determination of the chemical structure followed. 2. The six catechins in fresh tea leaves are easily epimerized by heat treatment to form the corresponding epimerized catechins, as shown in Table 2. Observation indicates that the six natural and six epimerized catechins can be present in heat-treated dried tea leaves or green teas. 3. The chemical structures of the ten catechins, which include the compounds in Table 1, are shown in Table 3. As the contents of the catechins in fresh tea leaves have been reported many times in the literature, it is certain that these compounds are naturally present in tea leaves. 4. Table 4 summarizes the chemical structures of eight minor catechin derivatives found in tea leaves and oolong teas, the first reporting authors, and the year reported. Because the presence of these catechin derivatives in fresh tea

  19. Molecular Dynamics Study on the Biophysical Interactions of Seven Green Tea Catechins with Cell Membranes

    Science.gov (United States)

    Molecular dynamics simulations were performed to study the interactions of bioactive catechins (flavonoids) commonly found in green tea with lipid bilayers, as model for cell membranes. Previously, a number of experimental studies rationalized catechin’s anticarcinogenic, antibacterial, and other be...

  20. Dietary flavonol, flavone and catechin intake and risk of colorectal cancer in the Netherlands Cohort Study

    NARCIS (Netherlands)

    Simons, C.C.J.M.; Hughes, L.A.E.; Arts, I.C.W.; Goldbohm, R.A.; Brandt, P.A. van den; Weijenberg, M.P.

    2009-01-01

    Dietary flavonoids are hypothesized to be protective against colorectal cancer, yet findings have been inconsistent. We examined the association of dietary flavonol, flavone and catechin intake with colorectal cancer endpoints within the Netherlands Cohort Study (NLCS). In addition, we explored whet

  1. Green tea catechins and their metabolites in human skin before and after exposure to ultraviolet radiation.

    Science.gov (United States)

    Clarke, Kayleigh A; Dew, Tristan P; Watson, Rachel E B; Farrar, Mark D; Osman, Joanne E; Nicolaou, Anna; Rhodes, Lesley E; Williamson, Gary

    2016-01-01

    Dietary flavonoids may protect against sunburn inflammation in skin. Preliminary reports using less complete analysis suggest that certain catechins and their metabolites are found in skin biopsies and blister fluid after consumption of green tea; however, it is not known if they are affected by solar-simulated ultraviolet radiation (UVR) or whether conjugated forms, with consequently altered bioactivity, are present. The present study tested the hypothesis that UVR affects the catechin levels in the skin of healthy volunteers after consumption of green tea and how catechins in the plasma are related to their presence in skin tissue samples. In an open oral intervention study, 11 subjects consumed green tea and vitamin C supplements daily for 3months. Presupplementation and postsupplementation plasma samples, suction blister fluid and skin biopsies were collected; the latter two samples were collected both before and after UVR. A sensitive high-performance liquid chromatography/mass spectrometric assay was used to measure the intact catechin metabolites, conjugates and free forms. Seven green tea catechins and their corresponding metabolites were identified postsupplementation in skin biopsies, 20 in blister fluid and 26 in plasma, with 15 green tea catechin metabolites present in both blister fluid and plasma. The valerolactone, O-methyl-M4-O-sulfate, a gut microbiota metabolite of catechins, was significantly increased 1.6-fold by UVR in blister fluid samples. In conclusion, there were some common catechin metabolites in the plasma and blister fluid, and the concentration was always higher in plasma. The results suggest that green tea catechins and metabolites are bioavailable in skin and provide a novel link between catechin metabolites derived from the skin and gut microbiota. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  2. Cardiovascular effects of green tea catechins: progress and promise.

    Science.gov (United States)

    Islam, Mohammed A

    2012-08-01

    Recently, there is a growing interest in the cardiovascular beneficial effects of green tea. Epidemiological and clinical studies have suggested that consumption of green tea is inversely associated with the risk of developing cardiovascular diseases. Catechins, the major flavonoid constituents of green tea, exert cardioprotective effects through diverse mechanisms that include reversal of endothelial dysfunctions, decreasing inflammatory biomarkers, and providing antioxidant, antiplatelet and antiproliferative effects. Moreover, dietary consumption of green tea catechins has beneficial effects on blood pressure and lipid parameters. This review will focus on discussing the latest research on the cardioprotective effects of green tea catechins and their underlying molecular mechanisms. Several recent patents pertinent to green tea and cardiovascular health will also be discussed. It is noteworthy that clinical studies involving green tea are fraught with multiple complexity and confounding factors. Therefore, a rigorous assessment of the effects of green tea catechins in well-controlled human trials will be required for better understanding of the effects of green tea in cardiovascular health.

  3. In vitro biological properties of flavonoid conjugates found in vivo.

    Science.gov (United States)

    Williamson, G; Barron, D; Shimoi, K; Terao, J

    2005-05-01

    For some flavonoids such as quercetin, isoflavones and catechins, the pathways of absorption and metabolism are now reasonably well characterised and understood. By definition, for biological activity of flavonoids to be manifest, the target tissue, which includes the blood and vascular system, must respond to the form(s) of flavonoid that it encounters. Bioavailability studies have shown that the circulating form of most flavonoids is as conjugates, with a few notable exceptions. There have been several recent papers on the in vitro biological properties of conjugates that have been found in vivo. This paper reviews the properties of these conjugates. Most of the information currently available is on quercetin glucuronides, but also on isoflavone and catechin conjugates. In addition to the biological properties of the conjugates, the partition coefficients and methods of synthesis are also presented.

  4. Flavonoids from the Red Alga Acanthophora spicifera

    Institute of Scientific and Technical Information of China (English)

    ZENG Long-Mei(曾陇梅); 曾陇梅; WANG Chao-Jie(王超杰); 王超杰; SU Jing-Yu(苏镜娱); 苏镜娱; LI Du(李笃); 李笃; OWEN Noel L.; OWEN Noel L; LU Yang(吕扬); 吕扬; LU Nan(鲁南); 鲁南; ZHENG Qi-Tai(郑启泰); 郑启泰

    2001-01-01

    Two new flavonoids, acanthophorin A (1) and acanthophorin B (2), along with three known compounds tiliroside (3),( - )-catechin (4) and quercetin (5) were isolated from the red alga Acanthophora spicifera. The structures of 1 and 2were determined to be kaempferol 3-O-α-L-fucopyranoside (1) and quercetin 3-O-α-L-fucopyranoside (2) by spectroscopic methods. Both 1 and 2 showed significant anfioxidant activity.

  5. Chromatographic separation and concentration of quercetin and (+)-catechin using mesoporous composites based on MCM-41

    Science.gov (United States)

    Karpov, S. I.; Belanova, N. A.; Korabel'nikova, E. O.; Nedosekina, I. V.; Roessner, F.; Selemenev, V. F.

    2015-05-01

    Data on chromatographic separation of quercetin and (+)-catechin-flavonoids with similar physicochemical (including sorption) properties—are presented. The highest efficiency of chromatographic process at high sorption capacity of the material with respect to quercetin and slightly lower capacity for (+)-catechin were observed when silylated composites of ordered MCM-41 type materials were used. The application of acetonitrile as a solvent increased the sorption capacity of the material and can be recommended for separation of related polyphenol substances and their determination using ordered MCM-41 modified with trimethylchlorosilane as a stationary phase in a chromatographic column.

  6. Intakes of total and individual flavonoids by US adults.

    Science.gov (United States)

    Bai, Wei; Wang, Chunyang; Ren, Cuirong

    2014-02-01

    Knowing the dietary flavonoid intake of individuals and populations is the first step to clearly understand their health effects. Dietary flavonoid intake studies have been hampered by the lack of flavonoid food composition data. The objectives of this study were to estimate intakes of individual, classes and total flavonoids in the US adults; to evaluate the effects of socio-demographic factors on the flavonoid consumption patterns; and to establish major dietary sources of flavonoids. We calculated flavonoid intakes using the most updated USDA flavonoid and isoflavone databases, and the National Health and Nutrition Examination Survey (NHANES) III 24-h dietary recall (DR). Estimated mean total flavonoid intake by US adults was 344.83 ± 9.13 mg/day. The flavan-3-ols (191.99 ± 6.84 mg/day) were the most abundant flavonoid class. The three most dominant individual flavonoids were catechin, epicatechin and polymers. Tea, wine, beer, citrus fruits and apples were the most important sources of total flavonoid intakes in the US adults.

  7. Trapping of growth factors by catechins: a possible therapeutical target for prevention of proliferative diseases.

    Science.gov (United States)

    Doss, Michael Xavier; Potta, Shiva Prasad; Hescheler, Jürgen; Sachinidis, Agapios

    2005-05-01

    The prevention of cancer through dietary intervention is currently receiving considerable attention. Several epidemiological studies substantiate that green tea has a protective effect against a variety of malignant proliferative disorders such as lung cancer, breast cancer and prostate cancer. This preventive potential of green tea against cancer is attributed to the biologically active flavonoids called catechins. Epigallocatechin 3-o-gallate, the major catechin found in green tea, mediates diverse physiological and pharmacological actions in bringing about the regression of the tumors and also lowers the risk of nonmalignant cardiovascular proliferative diseases. Much of the current research is being focused on how these catechins specifically bring about the regression of the experimentally induced tumors both in vitro and in vivo. These catechins exert diverse physiological effects against proliferative diseases by several mechanisms, most of which are not completely characterized. This review summarizes the mechanisms by which these catechins play an essential role in regulating the process of carcinogenesis, with a special emphasis on how these catechins antagonize the growth factor-induced proliferative disorders.

  8. Biosynthesis of catechin components is differentially regulated in dark-treated tea (Camellia sinensis L.).

    Science.gov (United States)

    Hong, Gaojie; Wang, Jie; Zhang, Yong; Hochstetter, Danielle; Zhang, Shuping; Pan, Yue; Shi, Yunlong; Xu, Ping; Wang, Yuefei

    2014-05-01

    Tea (Camellia sinensis L.) is a crop with both commercial and medicinal value with remarkably high polyphenol content in the form of catechins. To understand the molecular regulation of catechin biosynthesis in tea, we treated the tea plants with darkness. We used qRT-PCR to validate the expression of genes involved in catechin biosynthesis. It indicated that dark treatment displayed different effects on the genes participating in tea flavonoid (FL) pathway. The early genes of FL biosynthesis pathway, CHSI, F3H and DFR, remained at steady expression levels when treated by darkness. It is noteworthy that the expression level of LAR increased and the level of ANS decreased under dark conditions. The vanillin assay showed that the dark-treated plants contained lower levels of total catechins than those grown under normal conditions. The HPLC analysis further demonstrated the changes in biosynthesis of catechins under these conditions. In accordance with the gene expression pattern, the content of epicatechins (ECs) declined and that of catechins (Cs) was elevated in response to the darkness. Our study uncovered the molecular mechanisms and biochemical changes of shading in tea cultivation.

  9. Inhibition of catalase by tea catechins in free and cellular state: a biophysical approach.

    Science.gov (United States)

    Pal, Sandip; Dey, Subrata Kumar; Saha, Chabita

    2014-01-01

    Tea flavonoids bind to variety of enzymes and inhibit their activities. In the present study, binding and inhibition of catalase activity by catechins with respect to their structure-affinity relationship has been elucidated. Fluorimetrically determined binding constants for (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin gallate (ECG) with catalase were observed to be 2.27×106 M(-1) and 1.66×106 M(-1), respectively. Thermodynamic parameters evidence exothermic and spontaneous interaction between catechins and catalase. Major forces of interaction are suggested to be through hydrogen bonding along with electrostatic contributions and conformational changes. Distinct loss of α-helical structure of catalase by interaction with EGCG was captured in circular dichroism (CD) spectra. Gallated catechins demonstrated higher binding constants and inhibition efficacy than non-gallated catechins. EGCG exhibited maximum inhibition of pure catalase. It also inhibited cellular catalase in K562 cancer cells with significant increase in cellular ROS and suppression of cell viability (IC50 54.5 µM). These results decipher the molecular mechanism by which tea catechins interact with catalase and highlight the potential of gallated catechin like EGCG as an anticancer drug. EGCG may have other non-specific targets in the cell, but its anticancer property is mainly defined by ROS accumulation due to catalase inhibition.

  10. Inhibition of catalase by tea catechins in free and cellular state: a biophysical approach.

    Directory of Open Access Journals (Sweden)

    Sandip Pal

    Full Text Available Tea flavonoids bind to variety of enzymes and inhibit their activities. In the present study, binding and inhibition of catalase activity by catechins with respect to their structure-affinity relationship has been elucidated. Fluorimetrically determined binding constants for (--epigallocatechin gallate (EGCG and (--epicatechin gallate (ECG with catalase were observed to be 2.27×106 M(-1 and 1.66×106 M(-1, respectively. Thermodynamic parameters evidence exothermic and spontaneous interaction between catechins and catalase. Major forces of interaction are suggested to be through hydrogen bonding along with electrostatic contributions and conformational changes. Distinct loss of α-helical structure of catalase by interaction with EGCG was captured in circular dichroism (CD spectra. Gallated catechins demonstrated higher binding constants and inhibition efficacy than non-gallated catechins. EGCG exhibited maximum inhibition of pure catalase. It also inhibited cellular catalase in K562 cancer cells with significant increase in cellular ROS and suppression of cell viability (IC50 54.5 µM. These results decipher the molecular mechanism by which tea catechins interact with catalase and highlight the potential of gallated catechin like EGCG as an anticancer drug. EGCG may have other non-specific targets in the cell, but its anticancer property is mainly defined by ROS accumulation due to catalase inhibition.

  11. Anti- and pro-oxidant effects of (+)-catechin on hemoglobin-induced protein oxidative damage.

    Science.gov (United States)

    Lu, Naihao; Chen, Puqing; Yang, Qin; Peng, Yi-Yuan

    2011-06-01

    Evidence to support the role of heme proteins as major inducers of oxidative damage is increasingly present. Flavonoids have been widely used to ameliorate oxidative damage in vivo and in vitro, where the mechanism of this therapeutic action was usually dependent on their anti-oxidant effects. In this study, we investigated the influence of (+)-catechin, a polyphenol identified in tea, cocoa, and red wine, on hemoglobin-induced protein oxidative damage. It was found that (+)-catechin had the capacities to act as a free radical scavenger and reducing agent to remove cytotoxic ferryl hemoglobin, demonstrating apparent anti-oxidant activities. However, the presence of (+)-catechin surprisingly promoted hemoglobin-induced protein oxidation, which was probably due to the ability of this anti-oxidant to rapidly trigger the oxidative degradation of normal hemoglobin. In addition, hemoglobin-H2O2-induced protein carbonyl formation was significantly enhanced by (+)-catechin at lower concentrations, while it was efficiently inhibited when higher concentrations were used. These novel results showed that the dietary intake and therapeutic use of catechins might possess pro-oxidant activity through aggravating hemoglobin-related oxidative damage. The dual effects on hemoglobin redox reactions may provide new insights into the physiological implications of tea extract and wine (catechins) with cellular heme proteins.

  12. Goitrogenic/antithyroidal potential of green tea extract in relation to catechin in rats.

    Science.gov (United States)

    Chandra, Amar K; De, Neela

    2010-01-01

    Catechins are flavonoids found in abundance in green tea, have elicited high interest due to their beneficial effects on health. Though flavonoids have been reported to have an antithyroid effect and also to be goitrogenic there have been no reports about the effect of green tea on rat thyroid. The present study was designed to examine whether high doses of green tea has any harmful effect on thyroid physiology. For this purpose green tea extract was administered orally to male albino rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%, respectively. Similarly, pure catechin was administered at doses of 25, 50 and 100mg/kg body weight which is equivalent to above doses of green tea extract. Lower body weight gain associated with marked hypertrophy and/or hyperplasia of the follicles was noted in the high dose of green tea and catechin treated groups. Decreased activity of thyroid peroxidase and 5'-deiodinase I and substantially elevated thyroidal Na,K+ATPase activity have been observed. Moreover, serum T3 and T4 levels were found to reduce followed by significant elevation of serum TSH. Taken together, these results suggest that catechin present in green tea extract might behave as antithyroid agent and possibly the consumption of green tea at high dose could alter thyroid function adversely.

  13. Epicatechin and catechin in cocoa inhibit amyloid beta protein induced apoptosis.

    Science.gov (United States)

    Heo, Ho Jin; Lee, Chang Yong

    2005-03-09

    To elucidate additional health benefits of cocoa phytochemicals on the neurotoxicity induced by amyloid beta protein (Abeta), PC12 cells were treated with toxic peptide (Abeta(25)(-)(35)) and the effects of epicatechin, catechin, and cocoa were studied using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction, lactate dehydrogenase (LDH) release, and trypan blue exclusion methods. Significant increase in neuronal cell death was observed on PC12 cells treated with Abeta(25)(-)(35) (25 microM), while epicatechin and catechin and their mixture prevented the Abeta-induced neuronal cell death. Abeta treatment also led to the increased membrane instability of PC12 cells. The membrane protective effects of the phenolics determined by LDH release and trypan blue exclusion assays demonstrated that epicatechin, catechin, and their mixture protect cellular membrane from Abeta-induced cytotoxicity. In these three different cell viability assays, the mixture of epicatechin and catechin showed the highest protective effect and synergistic activity. The present results showed that the major flavonoids of cocoa, epicatechin and catechin, protect PC12 cells from Abeta-induced neurotoxicity, and suggest that cocoa may have anti-neurodegenerative effect in addition to other known chemopreventive effects.

  14. (-)-Catechin in cocoa and chocolate: occurrence and analysis of an atypical flavan-3-ol enantiomer.

    Science.gov (United States)

    Kofink, Michael; Papagiannopoulos, Menelaos; Galensa, Rudolf

    2007-07-04

    Cocoa contains high levels of different flavonoids. In the present study, the enantioseparation of catechin and epicatechin in cocoa and cocoa products by chiral capillary electrophoresis (CCE) was performed. A baseline separation of the catechin and epicatechin enantiomers was achieved by using 0.1 mol x L(-1) borate buffer (pH 8.5) with 12 mmol x L(-1) (2-hydroxypropyl)-gamma-cyclodextrin as chiral selector, a fused-silica capillary with 50 cm effective length (75 microm I.D.), +18 kV applied voltage, a temperature of 20 degrees C and direct UV detection at 280 nm. To avoid comigration or coelution of other similar substances, the flavan-3-ols were isolated and purified using polyamide-solid-phase-extraction and LC-MS analysis. As expected, we found (-)-epicatechin and (+)-catechin in unfermented, dried, unroasted cocoa beans. In contrast, roasted cocoa beans and cocoa products additionally contained the atypical flavan-3-ol (-)-catechin. This is generally formed during the manufacturing process by an epimerization which converts (-)-epicatechin to its epimer (-)-catechin. High temperatures during the cocoa bean roasting process and particularly the alkalization of the cocoa powder are the main factors inducing the epimerization reaction. In addition to the analysis of cocoa and cocoa products, peak ratios were calculated for a better differentiation of the cocoa products.

  15. (--Catechin in Cocoa and Chocolate: Occurence and Analysis of an Atypical Flavan-3-ol Enantiomer

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    Rudolf Galensa

    2007-07-01

    Full Text Available Cocoa contains high levels of different flavonoids. In the present study, the enantioseparation of catechin and epicatechin in cocoa and cocoa products by chiral capillary electrophoresis (CCE was performed. A baseline separation of the catechin and epicatechin enantiomers was achieved by using 0.1 mol·L−1 borate buffer (pH 8.5 with 12 mmol·L-1 (2-hydroxypropyl-γ-cyclodextrin as chiral selector, a fused-silica capillary with 50 cm effective length (75 μm I.D., +18 kV applied voltage, a temperature of 20°C and direct UV detection at 280 nm. To avoid comigration or coelution of other similar substances, the flavan-3-ols were isolated and purified using polyamide-solid-phase-extraction and LC-MS analysis. As expected, we found (--epicatechin and (+-catechin inunfermented, dried, unroasted cocoa beans. In contrast, roasted cocoa beans and cocoa products additionally contained the atypical flavan-3-ol (--catechin. This is generally formed during the manufacturing process by an epimerization which converts (--epicatechin to its epimer (--catechin. High temperatures during the cocoa bean roasting process and particularly the alkalization of the cocoa powder are the main factors inducing the epimerization reaction. In addition to the analysis of cocoa and cocoa products, peak ratios were calculated for a better differentiation of the cocoa products.

  16. Grape flavonoids and menopausal health.

    Science.gov (United States)

    Huntley, A L

    2007-12-01

    Grape flavonoids are members of a larger group of plant compounds called polyphenols. Epidemiological evidence relating to the traditional Mediterranean diet, which is high in polyphenols, derived from vegetables and red wine, suggests that dietary polyphenols are of benefit to health and reduce the incidence of cardiovascular disease. Overall, the evidence is promising for the benefit of grape flavonoids in the form of red wine, red grape juice and related preparations for cardiovascular risk factors. There are data to suggest a reduction in platelet activation, inflammation and low-density lipoprotein oxidation, and improvement of endothelial function with grape flavonoids. The evidence for grape flavonoids and renal function, cognition and cancer is less clear. However, it is important to note that much of this research has been carried out in animal and cell models; relatively little work has been done in humans and specifically on the health of menopausal women. There are no general safety concerns with ingestion of grape products. Obviously, consumption of red wine should be within recommended limits and it should be noted that grape juice has high sugar content. Grape flavonoids are also available as a supplement. In conclusion, it is likely that grape flavonoids do benefit the menopausal women. Further research is needed on the mode and dosage of application to maximize these benefits.

  17. Extraction and isolation of catechins from tea.

    Science.gov (United States)

    Vuong, Quan V; Golding, John B; Nguyen, Minh; Roach, Paul D

    2010-11-01

    Tea is a major source of catechins, which have become well known for their antioxidant potential. Numerous human, animal, and in vitro studies have linked tea catechins with prevention of certain types of cancers, reduction of the risks for obesity, diabetes, and cardiovascular disease, and improvement of the immune system. Tea catechins are widely used in various neutraceuticals, pharmaceuticals, and cosmetics for either enhancing product shelf-life or for enhancing human health. Thus, the demand for catechins has increased considerably. Catechins have been extracted and isolated from tea leaves by numerous methods through several steps including: treatment of the tea leaves, extraction of catechins from teas into solvents, isolation of catechins from other extracted components, and drying the preparations to obtain catechin extracts in a powder form. This paper outlines the physical and chemical properties of the tea catechins and reviews the extraction steps of the various extraction methods, as a basis to improve and further develop the extraction and isolation of the tea catechins.

  18. Preparation of tea catechins using polyamide.

    Science.gov (United States)

    Ye, Jian-Hui; Wang, Liu-Xiang; Chen, Hao; Dong, Jun-Jie; Lu, Jian-Liang; Zheng, Xin-Qiang; Wu, Ming-Yan; Liang, Yue-Rong

    2011-02-01

    An adsorption separation method using Polyamide-6 (PA) as an adsorbent was developed to separate catechins from green tea extract. The adsorption capacity of total catechins for PA was 193.128 mg g⁻¹ with an adsorption selectivity coefficient K(A)(B) of total catechins over caffeine 21.717, which was better than macroporous resin model HPD 600. The Langmuir model and the pseudo-second order mode were primely fitted to describe its equilibrium data and adsorption kinetics, respectively. PA column separation by two-step elution using water and 80% (v/v) aqueous ethanol was established to prepare catechins complex which contained 670.808 mg g⁻¹ total catechins and 1.828 mg g⁻¹ caffeine. It is considered that PA was a promising adsorbent for selective isolation of catechins.

  19. Preventive Effects of Catechins on Cardiovascular Disease

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    Xiao-Qiang Chen

    2016-12-01

    Full Text Available Catechins are polyphenolic phytochemicals with many important physiological activities that play a multifaceted health care function in the human body, especially in the prevention of cardiovascular disease. In this paper, various experimental and clinical studies have revealed the role of catechins in the prevention and treatment of cardiovascular disorders, and we review the preventive effects of catechins on cardiovascular disease from the following aspects: Regulating lipid metabolism, regulating blood lipid metabolism, vascular endothelial protection, and reducing blood pressure.

  20. Advances in the biotechnological glycosylation of valuable flavonoids.

    Science.gov (United States)

    Xiao, Jianbo; Muzashvili, Tamar S; Georgiev, Milen I

    2014-11-01

    The natural flavonoids, especially their glycosides, are the most abundant polyphenols in foods and have diverse bioactivities. The biotransformation of flavonoid aglycones into their glycosides is vital in flavonoid biosynthesis. The main biological strategies that have been used to achieve flavonoid glycosylation in the laboratory involve metabolic pathway engineering and microbial biotransformation. In this review, we summarize the existing knowledge on the production and biotransformation of flavonoid glycosides using biotechnology, as well as the impact of glycosylation on flavonoid bioactivity. Uridine diphosphate glycosyltransferases play key roles in decorating flavonoids with sugars. Modern metabolic engineering and proteomic tools have been used in an integrated fashion to generate numerous structurally diverse flavonoid glycosides. In vitro, enzymatic glycosylation tends to preferentially generate flavonoid 3- and 7-O-glucosides; microorganisms typically convert flavonoids into their 7-O-glycosides and will produce 3-O-glycosides if supplied with flavonoid substrates having a hydroxyl group at the C-3 position. In general, O-glycosylation reduces flavonoid bioactivity. However, C-glycosylation can enhance some of the benefits of flavonoids on human health, including their antioxidant and anti-diabetic potential.

  1. Molecular regulation of catechins biosynthesis in tea [Camellia sinensis (L.) O. Kuntze].

    Science.gov (United States)

    Rani, Arti; Singh, Kashmir; Ahuja, Paramvir S; Kumar, Sanjay

    2012-03-10

    Catechins are bioprospecting molecules present in tea and any effort towards metabolic engineering of this important moiety would require knowledge on gene regulation. These are synthesized through the activities of phenylpropanoid and flavonoid pathways. Expression regulation of various genes of these pathways namely phenylalanine ammonia-lyase (CsPAL), cinnamate 4-hydroxylase (CsC4H), p-coumarate:CoA ligase (Cs4CL), flavanone 3-hydroxylase (CsF3H), dihydroflavonol 4-reductase (CsDFR) and anthocyanidin reductase (CsANR) was accomplished previously. In depth analyses of the remaining genes namely, chalcone synthase (CsCHS), chalcone isomerase (CsCHI), flavonoid 3'5'-hydroxylase (CsF3'5'H) and anthocyanidin synthase (CsANS) were lacking. The objective of the work was to clone and analyze these genes so as to generate a comprehensive knowledge on the critical genes of catechins biosynthesis pathway. Gene expression analysis was carried out in response to leaf age and external cues (drought stress, abscisic acid, gibberellic acid treatments and wounding). A holistic analysis suggested that CsCHI, CsF3H, CsDFR, CsANS and CsANR were amongst the critical regulatory genes in regulating catechins content.

  2. Wine Flavonoids in Health and Disease Prevention.

    Science.gov (United States)

    Fernandes, Iva; Pérez-Gregorio, Rosa; Soares, Susana; Mateus, Nuno; de Freitas, Victor

    2017-02-14

    Wine, and particularly red wine, is a beverage with a great chemical complexity that is in continuous evolution. Chemically, wine is a hydroalcoholic solution (~78% water) that comprises a wide variety of chemical components, including aldehydes, esters, ketones, lipids, minerals, organic acids, phenolics, soluble proteins, sugars and vitamins. Flavonoids constitute a major group of polyphenolic compounds which are directly associated with the organoleptic and health-promoting properties of red wine. However, due to the insufficient epidemiological and in vivo evidences on this subject, the presence of a high number of variables such as human age, metabolism, the presence of alcohol, the complex wine chemistry, and the wide array of in vivo biological effects of these compounds suggest that only cautious conclusions may be drawn from studies focusing on the direct effect of wine and any specific health issue. Nevertheless, there are several reports on the health protective properties of wine phenolics for several diseases such as cardiovascular diseases, some cancers, obesity, neurodegenerative diseases, diabetes, allergies and osteoporosis. The different interactions that wine flavonoids may have with key biological targets are crucial for some of these health-promoting effects. The interaction between some wine flavonoids and some specific enzymes are one example. The way wine flavonoids may be absorbed and metabolized could interfere with their bioavailability and therefore in their health-promoting effect. Hence, some reports have focused on flavonoids absorption, metabolism, microbiota effect and overall on flavonoids bioavailability. This review summarizes some of these major issues which are directly related to the potential health-promoting effects of wine flavonoids. Reports related to flavonoids and health highlight some relevant scientific information. However, there is still a gap between the knowledge of wine flavonoids bioavailability and their health

  3. Targeting DNA methylation with green tea catechins.

    Science.gov (United States)

    Yiannakopoulou, Eugenia C

    2015-01-01

    Aberrant epigenetic alterations in the genome such as DNA methylation play a significant role in cancer development. Green tea catechins have been reported to modulate epigenetic processes. This review aims to synthesize evidence on the modulation of DNA methylation by green tea catechins. Green tea catechins have been reported to reverse DNA methylation of tumor suppressor genes and increase transcription of these genes. Green tea catechins and especially epigallocatechin gallate modulate DNA methylation by attenuating the effect of DNA methyltransferase 1 (DNMT1). However, the exact mechanism of DNMT1 inhibition is not delineated. Suggested mechanisms include direct enzymatic inhibition, indirect enzymatic inhibition, reduced DNMT1 expression and translation. The possible effect of green tea catechins on other pathways of DNA methylation, i.e. methyl-CpG binding domain proteins, has not been investigated. Furthermore, the link between redox properties and epigenetic modulation by green tea catechins has not been defined either. Since green tea catechins are natural compounds with a rather acceptable safety profile, further research on their action as inhibitors of DNA methylation seems worthwhile.

  4. Cancer Preventive Activities of Tea Catechins

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    Chung S. Yang

    2016-12-01

    Full Text Available Catechins are widely occurring in our diet and beverages. The cancer-preventive activities of catechins have been extensively studied. Of these, (−-epigallocatechin-3-gallate (EGCG, the principal catechin in green tea, has received the most attention. The inhibitory activities of tea catechins against carcinogenesis and cancer cell growth have been demonstrated in a large number of laboratory studies. Many mechanisms for modulating cancer signaling and metabolic pathways have been proposed based on numerous studies in cell lines with EGCG, the most active tea catechin. Nevertheless, it is not known whether many of these mechanisms indeed contribute to the anti-cancer activities in animals and in humans. Human studies have provided some results for the cancer preventive activities of tea catechins; however, the activities are not strong. This article reviews the cancer preventive activities and mechanisms of action of tea catechins involving their redox activities, biochemical properties and binding to key enzymes or signal transduction proteins. These mechanisms lead to suppression of cell proliferation, increased apoptosis and inhibition of angiogenesis. The relevance of the proposed mechanisms for cancer prevention are assessed in the light of the situation in vivo. The potential and possible problems in the application of tea and tea-derived products for cancer prevention are discussed.

  5. Cancer Preventive Activities of Tea Catechins.

    Science.gov (United States)

    Yang, Chung S; Wang, Hong

    2016-12-09

    Catechins are widely occurring in our diet and beverages. The cancer-preventive activities of catechins have been extensively studied. Of these, (-)-epigallocatechin-3-gallate (EGCG), the principal catechin in green tea, has received the most attention. The inhibitory activities of tea catechins against carcinogenesis and cancer cell growth have been demonstrated in a large number of laboratory studies. Many mechanisms for modulating cancer signaling and metabolic pathways have been proposed based on numerous studies in cell lines with EGCG, the most active tea catechin. Nevertheless, it is not known whether many of these mechanisms indeed contribute to the anti-cancer activities in animals and in humans. Human studies have provided some results for the cancer preventive activities of tea catechins; however, the activities are not strong. This article reviews the cancer preventive activities and mechanisms of action of tea catechins involving their redox activities, biochemical properties and binding to key enzymes or signal transduction proteins. These mechanisms lead to suppression of cell proliferation, increased apoptosis and inhibition of angiogenesis. The relevance of the proposed mechanisms for cancer prevention are assessed in the light of the situation in vivo. The potential and possible problems in the application of tea and tea-derived products for cancer prevention are discussed.

  6. Evaluation of non-covalent interactions between serum albumin and green tea catechins by affinity capillary electrophoresis.

    Science.gov (United States)

    Zinellu, Angelo; Sotgia, Salvatore; Scanu, Bastianina; Pisanu, Elisabetta; Giordo, Roberta; Cossu, Annalisa; Posadino, Anna Maria; Carru, Ciriaco; Pintus, Gianfranco

    2014-11-07

    The natural antioxidant-associated biological responses appear contradictory since biologically active dosages registered in vitro experiments are considerably higher if compared to concentrations found in vivo. The recent research indicates that natural antioxidants, including the major catechins of green tea epicatechin (EC), epigallocatechin (EGC), epicatechingallate (ECG) and epigallocatechingallate (EGCG) form non-covalent complexes with albumin, a crucial aspect that may modulate their plasma concentration, tissue delivery and biological activity. Affinity capillary electrophoresis (ACE) was used to characterize the binding of the four catechins to human serum albumin (HSA) and bovine serum albumin (BSA) at near-physiological conditions: 10 mmol/L phosphate buffer, HEPES 50 mmol/L (pH 7.5), temperature 37°C. The studied flavonoids displayed affinities toward the albumin with binding constants in the range 10(3)-10(5)M(-1), with a greater affinity of catechins toward HSA than BSA (between 3 and 3.5 fold higher). We also confirmed that catechins having a galloyl moiety (ECG and EGCG) have a higher binding affinity toward albumin than the catechins lacking the galloyl moiety (EC and EGC), and that for both albumins the order of affinity is EC

  7. High catechin concentrations detected in Withania somnifera (ashwagandha by high performance liquid chromatography analysis

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    Sulaiman Siti

    2011-08-01

    Full Text Available Abstract Background Withania somnifera is an important medicinal plant traditionally used in the treatment of many diseases. The present study was carried out to characterize the phenolic acids, flavonoids and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH scavenging activities in methanolic extracts of W. somnifera fruits, roots and leaves (WSFEt, WSREt and WSLEt. Methods WSFEt, WSREt and WSLEt was prepared by using 80% aqueous methanol and total polyphenols, flavonoids as well as DPPH radical scavenging activities were determined by spectrophotometric methods and phenolic acid profiles were determined by HPLC methods. Results High concentrations of both phenolics and flavonoids were detected in all parts of the plant with the former ranging between 17.80 ± 5.80 and 32.58 ± 3.16 mg/g (dry weight and the latter ranging between 15.49 ± 1.02 and 31.58 ± 5.07 mg/g. All of the three different plant parts showed strong DPPH radical scavenging activities (59.16 ± 1.20 to 91.84 ± 0.38%. Eight polyphenols (gallic, syringic, benzoic, p-coumaric and vanillic acids as well as catechin, kaempferol and naringenin have been identified by HPLC in parts of the plant as well. Among all the polyphenols, catechin was detected in the highest concentration (13.01 ± 8.93 to 30.61 ± 11.41 mg/g. Conclusion The results indicating that W. somnifera is a plant with strong therapeutic properties thus further supporting its traditional claims. All major parts of W. somnifera such as the roots, fruits and leaves provide potential benefits for human health because of its high content of polyphenols and antioxidant activities with the leaves containing the highest amounts of polyphenols specially catechin with strong antioxidant properties.

  8. Genotoxicity studies on green tea catechin.

    Science.gov (United States)

    Ogura, R; Ikeda, N; Yuki, K; Morita, O; Saigo, K; Blackstock, C; Nishiyama, N; Kasamatsu, T

    2008-06-01

    The beneficial effects of tea catechins are well documented. We evaluated the genotoxic potential of a green tea catechin preparation using established genotoxicity assays, including a bacterial reverse mutation assay (Ames test), a chromosomal aberration assay in cultured Chinese hamster lung cells (CHL/IU), a mouse lymphoma L5178Y/tk assay, and a bone marrow micronucleus (MN) assay in ICR CD mice and SD rats. No significant increases in the number of revertant colonies were observed in the Ames test, but positive responses were observed in two in vitro assays: the chromosomal aberration assay and mouse lymphoma L5178/tk assay. However, the in vivo study demonstrated no significant increase in micronucleated polychromatic erythrocytes (MNPCE) in the bone marrow of both ICR CD mice and SD rats administered a high dose of the green tea catechin preparation up to 2000mg/kg. Combined with favorable epidemiological information suggesting a chemopreventive effect of tea catechins on carcinogenesis, we conclude that green tea catechin presents no significant genotoxic concern under the anticipated conditions of use. These results are consistent with other genotoxicity studies of tea catechins, which show minimal, if any, genotoxic potential.

  9. A review of the epidemiological evidence on tea, flavonoids, and lung cancer.

    Science.gov (United States)

    Arts, Ilja C W

    2008-08-01

    Tea and its main bioactive ingredients, the flavonoids, have been associated with human cancer for several decades. In this article, an overview is provided of observational epidemiological studies of lung cancer incidence in relation to intake of green tea, black tea, flavonols/flavones, and catechins. A PubMed search was conducted in September 2007. Articles were selected if they provided risk ratios (relative risk or odds ratio) for lung cancer and were of observational design (cohort, case-control, or case-cohort). Three of 12 studies reported a significantly lower risk of lung cancer with a high intake of flavonoids, whereas 1 study reported a significantly increased risk. After stratification by type of flavonoid, catechin intake was no longer associated with lung cancer risk in 3 of 4 studies available. For tea, 4 of 20 studies reported significantly reduced risks with high intake. Two studies found significantly increased risk ratios, but both were older studies. Findings were similar for green and black tea but became more significant when only methodologically sounder cohort studies were considered. When tea intake and lung cancer were studied among never- or former smokers to eliminate the confounding effect of smoking, 4 of 7 reported associations were significantly protective. In general, the studies on tea, flavonoids, and lung cancer risk indicate a small beneficial association, particularly among never-smokers. More well-designed cohort studies, in particular for catechins, are needed to strengthen the evidence on effects of long-term exposure to physiological doses of dietary flavonoids.

  10. Investigation of Phenolic, Flavonoid, and Vitamin Contents in Different Parts of Korean Ginseng (Panax ginseng C.A. Meyer)

    Science.gov (United States)

    Kim, Ji-Sang

    2016-01-01

    This study investigated the phenolic, flavonoid, and vitamin constituents in the main root, root hair, and leaf of ginseng. The total individual phenolic and flavonoid contents were the highest in the leaf, followed by the main root and root hair. Ferulic acid and m-coumaric acid were found to be the major phenolics in the main root and root hair, while p-coumaric acid and m-coumaric acid were the major phenolics in the leaf. Catechin was the major flavonoid component in the main root and root hair, while catechin and kaempferol were the major flavonoid components in the leaf. Pantothenic acid was detected in the highest quantity in the non-leaf parts of ginseng, followed by thiamine and cobalamin. Linolenic acid and menadione were the major components in all parts of ginseng. PMID:27752503

  11. Histochemical evaluation of catechins in PEG stressed transgenic tea plants using catechin-specific-diazotized sulfanilamide reagent.

    Science.gov (United States)

    Bhattacharya, A; Sharma, M; Gulati, A; Joshi, R; Chanda, S K; Ahuja, P S

    2015-01-01

    We investigated the applicability of catechin-specific-reagent (CSR) for histochemical evaluation of catechins. The diazotized arylamine moiety in CSR reacts specifically with the A-ring of catechins to yield a golden yellow complex. This makes it highly specific for spectrophotometric quantification of catechins. Therefore, microtome cut sections of untransformed and osmotin-expressing transgenic leaves and stem of tea were stained with CSR. We found catechins in the form of golden yellow globules. The catechin globules increased in the structurally intact and highly turgid cells of osmotin expressing transgenic tea plants after stress treatment with 20% PEG; by contrast, the cells in non-transgenic plants accumulated fewer catechin globules. Spectrophotometric quantification of catechins also confirmed higher levels in transgenics compared to untransformed plants. We found elevated accumulation of catechins in stress tolerant cells of tea leaves.

  12. Catechins and Procyanidins of Ginkgo biloba Show Potent Activities towards the Inhibition of β-Amyloid Peptide Aggregation and Destabilization of Preformed Fibrils

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    Haiyan Xie

    2014-04-01

    Full Text Available Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761. In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds, six of them were identified as (+-catechin, (−-epicatechin, (−-gallocatechin, (−-epigallocatechin and procyanidins B1 and B3. The activities of these polyphenols in the inhibition of Aβ42 aggregation and the destabilization of preformed fibrils were evaluated using biochemical assays, which showed that all six of the polyphenols, as well as a fraction of the extract of Ginkgo biloba leaves (EGb containing catechins and procyanidins, exerted potent inhibitory activities towards Aβ42 aggregation and could also destabilize the performed fibrils. Catechins and procyanidins can therefore be regarded as the potent active constituents of EGb761 in terms of their inhibition of Aβ42 aggregation and destabilization of the fibrils. Although quantitative mass spectroscopic analysis revealed that the catechins and procyanidins are only present in low concentrations in EGb761, these components should be studied in greater detail because of their potent inhibitory effects towards Aβ42 aggregation and their ability to destabilize preformed fibrils, especially during the quality control of Ginkgo leaves and the manufacture of Ginkgo products.

  13. Catechins and procyanidins of Ginkgo biloba show potent activities towards the inhibition of β-amyloid peptide aggregation and destabilization of preformed fibrils.

    Science.gov (United States)

    Xie, Haiyan; Wang, Jing-Rong; Yau, Lee-Fong; Liu, Yong; Liu, Liang; Han, Quan-Bin; Zhao, Zhongzhen; Jiang, Zhi-Hong

    2014-04-22

    Catechins and procyanidins, together with flavonoid glycosides and terpene trilactones, are three important categories of components in the standard extract of Ginkgo biloba leaves (EGb761). In this research, catechins and proanthocyanidins were found to exist in both the extract of Ginkgo leaves and Ginkgo products. By comparing with reference compounds, six of them were identified as (+)-catechin, (-)-epicatechin, (-)-gallocatechin, (-)-epigallocatechin and procyanidins B1 and B3. The activities of these polyphenols in the inhibition of Aβ42 aggregation and the destabilization of preformed fibrils were evaluated using biochemical assays, which showed that all six of the polyphenols, as well as a fraction of the extract of Ginkgo biloba leaves (EGb) containing catechins and procyanidins, exerted potent inhibitory activities towards Aβ42 aggregation and could also destabilize the performed fibrils. Catechins and procyanidins can therefore be regarded as the potent active constituents of EGb761 in terms of their inhibition of Aβ42 aggregation and destabilization of the fibrils. Although quantitative mass spectroscopic analysis revealed that the catechins and procyanidins are only present in low concentrations in EGb761, these components should be studied in greater detail because of their potent inhibitory effects towards Aβ42 aggregation and their ability to destabilize preformed fibrils, especially during the quality control of Ginkgo leaves and the manufacture of Ginkgo products.

  14. Reaction of Acetaldehyde with Wine Flavonoids in the Presence of Sulfur Dioxide.

    Science.gov (United States)

    Sheridan, Marlena K; Elias, Ryan J

    2016-11-16

    Acetaldehyde is responsible for many of the beneficial changes that occur in red wine as a result of oxidation. Ethylidene bridges are formed between flavonoids upon their reaction with acetaldehyde, which can contribute to improvements in color stability and SO2-resistant pigments. In the present study, the reactions between acetaldehyde and various flavonoids (catechin, tannins from grape seed extract, and malvidin-3-glucoside) were examined in a model wine system. Lower pH conditions were seen to significantly increase the rate of reaction with acetaldehyde, whereas dissolved oxygen did not affect the rate. In systems containing SO2, the rate of reaction of acetaldehyde with catechin was slowed but was not prevented until SO2 was in great excess. Significant improvements in color stability were also observed after treatment with acetaldehyde, despite the presence of equimolar SO2. These results demonstrate that acetaldehyde is reactive in its sulfonate form, which is contrary to widely held assumptions. In addition, the products of the reaction of flavonoids with acetaldehyde were characterized using MALDI-TOF MS in this study. Ethyl-bridged catechin nonamers were observed, as well as anthocyanin and pyranoanthocyanin derivatives of catechin and tannin oligomers. The results of this work illustrate the significance of acetaldehyde reactions in forming stable pigments in wine and the reactivity of acetaldehyde from its sulfonate form.

  15. Structure-Activity Association of Flavonoids in Lung Diseases

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    João Henrique G. Lago

    2014-03-01

    Full Text Available Flavonoids are polyphenolic compounds classified into flavonols, flavones, flavanones, isoflavones, catechins, anthocyanidins, and chalcones according to their chemical structures. They are abundantly found in Nature and over 8,000 flavonoids have from different sources, mainly plant materials, have been described. Recently reports have shown the valuable effects of flavonoids as antiviral, anti-allergic, antiplatelet, antitumor, antioxidant, and anti-inflammatory agents and interest in these compounds has been increasing since they can be helpful to human health. Several mechanisms of action are involved in the biological properties of flavonoids such as free radical scavenging, transition metal ion chelation, activation of survival genes and signaling pathways, regulation of mitochondrial function and modulation of inflammatory responses. The anti-inflammatory effects of flavonoids have been described in a number of studies in the literature, but not frequently associated to respiratory disease. Thus, this review aims to discuss the effects of different flavonoids in the control of lung inflammation in some disorders such as asthma, lung emphysema and acute respiratory distress syndrome and the possible mechanisms of action, as well as establish some structure-activity relationships between this biological potential and chemical profile of these compounds.

  16. FLAVONOIDS OF SALVIA MICROSTEGIA

    OpenAIRE

    A. ULUBELEN**, Z. SUKAL*, B. HALFON*

    2015-01-01

    Three flavonoids, apigenin, apigenin 7-0-glucoside and chrysoeriol, havebeen isolated from the aerial parts of Salvia microstegia Boiss. et Bal.Key words: Salvia, flavonoids, apigenin, apigenin 7-O-glucoside, chrysoeriol.

  17. Antioxidative properties of flavonoids

    NARCIS (Netherlands)

    Bowedes, T.C.F.; Luttikhold, J.; Stijn, van M.F.M.; Visser, M.; Norren, van K.; Vermeulen, M.A.R.; Leeuwen, P.A.M.

    2011-01-01

    Evidence accumulates that a family of plant compounds, known as flavonoids, can prevent or slow down the progression of cardiovascular diseases, cancer, inflammatory and neurodegenerative diseases. Flavonoids are considered beneficial, this is often attributed to their powerful antioxidant propertie

  18. Pulse radiolysis study of the reactions of catechins with nitrogen dioxide

    Science.gov (United States)

    Gebicki, Jerzy L.; Meisner, Piotr; Stawowska, Katarzyna; Gebicka, Lidia

    2012-12-01

    Nitrogen dioxide (•NO2), one of the oxidizing radicals formed in vivo is suspected to play a role in various pathophysiological processes. The reactions of •NO2 with dietary catechins, the group of flavonoids present in high amounts in green tea and red wine, have been investigated by pulse radiolysis method. The kinetics of the reaction of •NO2 with gallic acid have been also studied for comparison. The spectra of transient intermediates are presented. The rate constants of the reaction of •NO2 with catechin, epigallocatechin, epigallocatechin gallate and gallic acid determined by the competition method with 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) at pH 7.0 and room temperature have been found to be 0.9, 1.0, 2.3 and 0.5×108 M-1 s-1, respectively. The values for catechins are among the highest reported for the reactions of •NO2 with non-radical compounds.

  19. Catechins as Potential Mediators of Cardiovascular Health.

    Science.gov (United States)

    Mangels, Daniel R; Mohler, Emile R

    2017-05-01

    The impact of diet on cardiovascular disease has become an increasingly relevant topic as ongoing epidemiological evidence continues to demonstrate clear associations with disease burden and mortality. Certain diets, such as those high in sodium and saturated fat, are associated with cardiovascular disease states, while other diets can be cardioprotective. However, there is limited knowledge on how the micro- and macronutrients within such cardioprotective diets afford their benefits. One such micronutrient is the catechin class, which are naturally occurring compounds in plant foods, such as teas, cocoa, wine, pears, and apples. Recent evidence reveals that catechins may be a key mediator in cardiovascular health via mechanisms of blood pressure reduction, flow-mediated vasodilation, and atherosclerosis attenuation. This review evaluates the current literature on the interplay between catechins and cardiovascular disease, which may have important implications for nutrition counseling and pharmaceutical drug development. © 2017 American Heart Association, Inc.

  20. Photochemistry of Flavonoids

    Directory of Open Access Journals (Sweden)

    Jan H. Van der Westhuizen

    2010-08-01

    Full Text Available Flavonoids and their photochemical transformations play an important role in biological processes in nature. Synthetic photochemistry allows access to molecules that cannot be obtained via more conventional methods. This review covers all published synthetic photochemical transformations of the different classes of flavonoids. It is first comprehensive review on the photochemistry of flavonoids.

  1. Interaction of catechins with aluminum in vitro

    Institute of Scientific and Technical Information of China (English)

    唐德松; 沈生荣; 陈勋; 张玉艳; 许重阳

    2004-01-01

    Tea is one of the most popular beverages, consumed by over two thirds of the world's population; but the aluminum accumulation property of tea plant is becoming the focus of many researches because of aluminum's known adverse effect on human health. Investigation of the interactions of catechins with A13+ showed that during the interaction of catechins with A13+, the UV-vis spectrum of catechins was changed. Absorption of EGCG at 274 nm decreased and increased at 322 nm; EC and C's at 278 nm changed little. The ratio of A13+ to EGCG was 1:1 in pH 5.0 buffer solution; in pH 6.2 buffer solution, the ratio in the A1-EGCG complex was 1:1. Interestingly, while the ratio reached to over 2, after the complex of A1-EGCG started polymerization, the ratio in the polymer was 2:1. In pH 6.2 buffer solution, the complex behavior of C with A13+ was the same as that of EGCG, with a little difference for EC. When the ratio of A13+ to EC was1. It was found that the ratio of A13+ to EC in the polymer was 1:1. Polymerization of A1-catechin complexes might reduce aluminum absorption in the intestine. Kow value was also employed to study the properties of aluminum species in tea infusion (at gastric and intestine pH condition) and the effect of catechins and tea polyphenols on Kow in buffer solution. Results showed that Kow value rose much higher at the intestine pH than at the gastric pH. Tea polyphenols and catechins could greatly reduce aluminum Kow value in acetic buffer,indicating that these compounds may reduce aluminum absorption during tea intake.

  2. Interaction of catechins with aluminum in vitro

    Institute of Scientific and Technical Information of China (English)

    唐德松; 沈生荣; 陈勋; 张玉艳; 许重阳

    2004-01-01

    Tea is one of the most popular beverages, consumed by over two thirds of the world's population; but the aluminum accumulation property of tea plant is becoming the focus of many researches because of aluminum's known adverse effect on human health. Investigation of the interactions of catechins with Al3+ showed that during the interaction of catechins with Al3+, the UV-vis spectrum of catechins was changed. Absorption of EGCG at 274 nm decreased and increased at 322 nm; EC and C's at 278 nm changed little. The ratio of Al3+ to EGCG was 1:1 in pH 5.0 buffer solution; in pH 6.2 buffer solution, the ratio in the Al-EGCG complex was 1:1. Interestingly, while the ratio reached to over 2, after the complex of Al-EGCG started polymerization, the ratio in the polymer was 2:1. In pH 6.2 buffer solution, the complex behavior of C with Al3+ was the same as that of EGCG, with a little difference for EC. When the ratio of Al3+ to EC was 1. It was found that the ratio of Al3+ to EC in the polymer was 1:1. Polymerization of Al-catechin complexes might reduce aluminum absorption in the intestine. Kow value was also employed to study the properties of aluminum species in tea infusion (at gastric and intestine pH condition) and the effect of catechins and tea polyphenols on Kow in buffer solution. Results showed that Kow value rose much higher at the intestine pH than at the gastric pH. Tea polyphenols and catechins could greatly reduce aluminum Kow value in acetic buffer, indicating that these compounds may reduce aluminum absorption during tea intake.

  3. Application of Pseudomonas fluorescens to Blackberry under Field Conditions Improves Fruit Quality by Modifying Flavonoid Metabolism.

    Directory of Open Access Journals (Sweden)

    Daniel Garcia-Seco

    Full Text Available Application of a plant growth promoting rhizobacterium (PGPR, Pseudomonas fluorescens N21.4, to roots of blackberries (Rubus sp. is part of an optimised cultivation practice to improve yields and quality of fruit throughout the year in this important fruit crop. Blackberries are especially rich in flavonoids and therefore offer potential benefits for human health in prevention or amelioration of chronic diseases. However, the phenylpropanoid pathway and its regulation during ripening have not been studied in detail, in this species. PGPR may trigger flavonoid biosynthesis as part of an induced systemic response (ISR given the important role of this pathway in plant defence, to cause increased levels of flavonoids in the fruit. We have identified structural genes encoding enzymes of the phenylpropanoid and flavonoid biosynthetic pathways catalysing the conversion of phenylalanine to the final products including flavonols, anthocyanins and catechins from blackberry, and regulatory genes likely involved in controlling the activity of pathway branches. We have also measured the major flavonols, anthocyanins and catechins at three stages during ripening. Our results demonstrate the coordinated expression of flavonoid biosynthetic genes with the accumulation of anthocyanins, catechins, and flavonols in developing fruits of blackberry. Elicitation of blackberry plants by treatment of roots with P.fluorescens N21.4, caused increased expression of some flavonoid biosynthetic genes and an accompanying increase in the concentration of selected flavonoids in fruits. Our data demonstrate the physiological mechanisms involved in the improvement of fruit quality by PGPR under field conditions, and highlight some of the genetic targets of elicitation by beneficial bacteria.

  4. Dietary catechins and procyanidins modulate zinc homeostasis in human HepG2 cells.

    Science.gov (United States)

    Quesada, Isabel M; Bustos, Mario; Blay, Mayte; Pujadas, Gerard; Ardèvol, Anna; Salvadó, M Josepa; Bladé, Cinta; Arola, Lluís; Fernández-Larrea, Juan

    2011-02-01

    Catechins and their polymers procyanidins are health-promoting flavonoids found in edible vegetables and fruits. They act as antioxidants by scavenging reactive oxygen species and by chelating the redox-active metals iron and copper. They also behave as signaling molecules, modulating multiple cell signalling pathways and gene expression, including that of antioxidant enzymes. This study aimed at determining whether catechins and procyanidins interact with the redox-inactive metal zinc and at assessing their effect on cellular zinc homeostasis. We found that a grape-seed procyanidin extract (GSPE) and the green tea flavonoid (-)-epigallocatechin-3-gallate (EGCG) bind zinc cations in solution with higher affinity than the zinc-specific chelator Zinquin, and dose-dependently prevent zinc-induced toxicity in the human hepatocarcinoma cell line HepG2, evaluated by the lactate dehydrogenase test. GSPE and EGCG hinder intracellular accumulation of total zinc, measured by atomic flame absorption spectrometry, concomitantly increasing the level of cytoplasmic labile zinc detectable by Zinquin fluorescence. Concurrently, GSPE and EGCG inhibit the expression, evaluated at the mRNA level by quantitative reverse transcriptase-polymerase chain reaction, of zinc-binding metallothioneins and of plasma membrane zinc exporter ZnT1 (SLC30A1), while enhancing the expression of cellular zinc importers ZIP1 (SLC39A1) and ZIP4 (SLC39A4). GSPE and EGCG also produce all these effects when HepG2 cells are stimulated to import zinc by treatment with supplemental zinc or the proinflammatory cytokine interleukin-6. We suggest that extracellular complexation of zinc cations and the elevation of cytoplasmic labile zinc may be relevant mechanisms underlying the modulation of diverse cell signaling and metabolic pathways by catechins and procyanidins.

  5. Extraction of Catechins from Green Tea Using Ultrasound

    Science.gov (United States)

    Koiwai, Hitoshi; Masuzawa, Nobuyoshi

    2007-07-01

    Recently, hazardous properties of synthetic substances contained in foods and medicines have been observed. Therefore, the pharmacological actions of natural substances became the focus of attention. Catechins, which are polyphenols, are abundant in green tea. To extract green tea catechins, there are two types of method: extraction using hot water and organic solvents. In the extraction using hot water, green tea quality deteriorates and catechins are destroyed due to the heat applied. Accordingly, the extraction of catechins at low temperatures is appropriate, although the efficiency is low. Therefore, we attempted to increase the amount of catechins extracted with ultrasonic irradiation.

  6. Wine Flavonoids in Health and Disease Prevention

    Directory of Open Access Journals (Sweden)

    Iva Fernandes

    2017-02-01

    Full Text Available Wine, and particularly red wine, is a beverage with a great chemical complexity that is in continuous evolution. Chemically, wine is a hydroalcoholic solution (~78% water that comprises a wide variety of chemical components, including aldehydes, esters, ketones, lipids, minerals, organic acids, phenolics, soluble proteins, sugars and vitamins. Flavonoids constitute a major group of polyphenolic compounds which are directly associated with the organoleptic and health-promoting properties of red wine. However, due to the insufficient epidemiological and in vivo evidences on this subject, the presence of a high number of variables such as human age, metabolism, the presence of alcohol, the complex wine chemistry, and the wide array of in vivo biological effects of these compounds suggest that only cautious conclusions may be drawn from studies focusing on the direct effect of wine and any specific health issue. Nevertheless, there are several reports on the health protective properties of wine phenolics for several diseases such as cardiovascular diseases, some cancers, obesity, neurodegenerative diseases, diabetes, allergies and osteoporosis. The different interactions that wine flavonoids may have with key biological targets are crucial for some of these health-promoting effects. The interaction between some wine flavonoids and some specific enzymes are one example. The way wine flavonoids may be absorbed and metabolized could interfere with their bioavailability and therefore in their health-promoting effect. Hence, some reports have focused on flavonoids absorption, metabolism, microbiota effect and overall on flavonoids bioavailability. This review summarizes some of these major issues which are directly related to the potential health-promoting effects of wine flavonoids. Reports related to flavonoids and health highlight some relevant scientific information. However, there is still a gap between the knowledge of wine flavonoids

  7. Structural Properties of Green Tea Catechins.

    Science.gov (United States)

    Botten, Dominic; Fugallo, Giorgia; Fraternali, Franca; Molteni, Carla

    2015-10-08

    Green tea catechins are polyphenols which are believed to provide health benefits; they are marketed as health supplements and are studied for their potential effects on a variety of medical conditions. However, their mechanisms of action and interaction with the environment at the molecular level are still not well-understood. Here, by means of atomistic simulations, we explore the structural properties of four green tea catechins, in the gas phase and water solution: specifically, (-)-epigallocatechin-3-gallate, which is the most abundant, (-)-epicatechin-3-gallate, (-)-epigallocatechin-3-O-(3-O-methyl)-gallate, and (-)-epigallocatechin. We characterize the free energy conformational landscapes of these catechins at ambient conditions, as a function of the torsional degrees of freedom of the pholyphenolic rings, determining the stable conformers and their connections. We show that these free energy landscapes are only subtly influenced by the interactions with the solvent and by the structural details of the polyphenolic rings. However, the number and position of the hydroxyl groups (or their sustituents) and the presence/absence of the galloyl moiety have significant impact on the selected catechin solvation shells and hydrogen bond capabilities, which are ultimately linked to their ability to interact with and affect the biological environment.

  8. Level of catechin, myricetin, quercetin and isoquercitrin in buckwheat (Fagopyrum esculentum Moench), changes of their levels during vegetation and their effect on the growth of selected weeds.

    Science.gov (United States)

    Kalinova, Jana; Vrchotova, Nadezda

    2009-04-01

    Buckwheat is well-known as a crop rich in flavonoids, however, attention has usually only been paid to the main flavonoid rutin as an important natural antioxidant or as a possible allelopathic compound. Therefore, some of the other constituents found within individual plant parts of buckwheat (isoquercitrin, quercetin, catechin, and myricetin), as well as changes of their level during the growing season, were determined by HPLC analysis. The effects of these compounds on plant growth were proved on seven plant species. In buckwheat, isoquercitrin represented the largest component of the selected compounds. The strongest inhibitive effects on the growth of those selected plants were produced by catechin. Quercetin and isoquercitrin had weak inhibitive effects. Myricetin did not show any influence on plant growth. Hence we suppose that myricetin, isoquercetin and quercetin do not have important function in allelopathy of buckwheat. Buckwheat as row material for functional foods could be a significant source of another antioxidant, isoquercitrin.

  9. Interactions between milk fat globules and green tea catechins.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-05-15

    The determination of putative chemical interactions between the milk fat globule membrane and green tea catechins provided useful information about the role of milk fat globules (MFGs) in high-fat dairy systems, such as cheese, and containing bioactive compounds, such as tea catechins. Catechins from green tea (125-1,000 ppm), including (+)-catechin, (-)-epigallocatechin gallate, and green tea extract were added to washed MFGs to examine possible interactions. The addition of catechins gave a significant change in the size and ζ-potential of MFGs. The recovery of different catechins from the milk fat globule suspensions was found to vary, suggesting selective association with the milk fat globule membranes. The interactions were further investigated using transmission electron microscopy and Fourier transform infra-red spectroscopy. It is suggested that catechins are localised in association with milk fat globule membrane domains as they contain both hydrophobic and hydrophilic moieties with potential points of molecular interaction.

  10. Free radical scavenging activity of Eagle tea and their flavonoids

    Directory of Open Access Journals (Sweden)

    Qiong Meng

    2012-06-01

    Full Text Available In this study, an online HPLC-DAD-MS coupled with 2,2′-azinobis (3-ethylbenzthiazoline-6-sulfonic acid diammonium salt (ABTS assay was employed for evaluating free radical scavenging activity of Eagle tea and their active components. Twenty-three chromatographic peaks were detected, and nineteen components had free radical scavenging activity. Among them, eight compounds were identified as flavonoids (hyperin, isoquercitrin, quercitrin, quercetin, kaempferol, catechins, chlorogenic acid and epicatechin based on MS data and standard chromatographic characters.

  11. Sugar Substitutes

    Science.gov (United States)

    ... drinks. You may also have heard them called "artificial sweeteners" or "non-caloric sweeteners." They can be used ... of nutrition for your body.What sugar substitutes/artificial sweeteners are approved by the FDA?The following sugar ...

  12. Quercetin 7-O-glucoside suppresses nitrite-induced formation of dinitrosocatechins and their quinones in catechin/nitrite systems under stomach simulating conditions.

    Science.gov (United States)

    Morina, Filis; Takahama, Umeo; Yamauchi, Ryo; Hirota, Sachiko; Veljovic-Jovanovic, Sonja

    2015-01-01

    Foods of plant origin contain flavonoids. In the adzuki bean, (+)-catechin, quercetin 3-O-rutinoside (rutin), and quercetin 7-O-β-D-glucopyranoside (Q7G) are the major flavonoids. During mastication of foods prepared from the adzuki bean, the flavonoids are mixed with saliva and swallowed into the stomach. Here we investigated the interactions between Q7G and (+)-catechin at pH 2, which may proceed in the stomach after the ingestion of foods prepared from the adzuki bean. Q7G reacted with nitrous acid producing nitric oxide (˙NO) and a glucoside of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone. (+)-Catechin reacted with nitrous acid producing ˙NO and 6,8-dinitrosocatechin. The production of the dinitrosocatechin was partly suppressed by Q7G, and the suppression resulted in the enhancement of Q7G oxidation. 6,8-Dinitrosocatechin reacted further with nitrous acid generating the o-quinone, and the quinone formation was effectively suppressed by Q7G. In the flavonoids investigated, the suppressive effect decreased in the order Q7G≈quercetin>kaempferol>quercetin 4'-O-glucoside>rutin. Essentially the same results were obtained when (-)-epicatechin was used instead of (+)-catechin. The results indicate that nitrous acid-induced formation of 6,8-dinitrosocatechins and the o-quinones can be suppressed by flavonols in the stomach, and that both a hydroxyl group at C3 and ortho-hydroxyl groups in the B-ring are required for efficient suppression.

  13. Separation and identification of flavonoids from fistular onion stalk (Allium fisturosum L. var. Caespitosum Makio).

    Science.gov (United States)

    Fu, Qinqin; Liu, Jingyou; Zhang, Changgong; Zhou, Yinbo; Zhang, Geng; Ma, Dan; Yang, Xinzhou

    2010-04-01

    The chemical constituents of fistular onion stalk obtained by supercritical CO(2) extraction were separated and purified by silica gel and sephadex LH-20 gel column chromatography and the preparative TLC method and four flavonoids were obtained. On the basis of the spectral data, they were structurally identified as (+)-catechin, (-)-epicatechin, astragalin, and 3-O-beta-D(2-O-beta-D-glucopyranosyl)-glucopyranosides of kaempferol.

  14. Preconditioning and Acute Effects of Flavonoids in Protecting Cardiomyocytes from Oxidative Cell Death

    Directory of Open Access Journals (Sweden)

    Masoumeh Akhlaghi

    2012-01-01

    Full Text Available While flavonoids can reportedly protect against cardiac ischemia-reperfusion injury, the relative effectiveness of different flavonoids and the mechanisms involved are unclear. We compared protection by different flavonoids using rat embryonic ventricular H9c2 cells subjected to simulated ischemia-reperfusion (IR and to tert-butyl hydroperoxide (t-buOOH. Characterization of the IR model showed the relative contributions of glucose, serum, and oxygen deprivation to cell death. With long-term (2-3 day pretreatment before IR the best protection was given by catechin, epigallocatechin gallate, proanthocyanidins, and ascorbate, which protected at all doses. Quercetin protected (34% at 5 μM but was cytotoxic at higher doses. Cyanidin protected mildly (10–15% at 5 and 20 μM, while delphinidin had no effect at 5 μM and was cytotoxic at higher doses. Comparing long-term and acute protection by catechin, a higher concentration was needed for benefit with acute (1 hr pretreatment. With a pure oxidative stress (t-buOOH only quercetin significantly protected with 3-day pretreatment, while with short-term (1 h pretreatments protection was best with quercetin and epigallocatechin gallate. The results suggest catechins to be especially useful as IR preconditioning agents, while quercetin and epigallocatechin gallate may be the most protective acutely in situations of oxidative stress.

  15. Antimicrobial activity of flavonoids.

    Science.gov (United States)

    Cushnie, T P Tim; Lamb, Andrew J

    2005-11-01

    Flavonoids are ubiquitous in photosynthesising cells and are commonly found in fruit, vegetables, nuts, seeds, stems, flowers, tea, wine, propolis and honey. For centuries, preparations containing these compounds as the principal physiologically active constituents have been used to treat human diseases. Increasingly, this class of natural products is becoming the subject of anti-infective research, and many groups have isolated and identified the structures of flavonoids possessing antifungal, antiviral and antibacterial activity. Moreover, several groups have demonstrated synergy between active flavonoids as well as between flavonoids and existing chemotherapeutics. Reports of activity in the field of antibacterial flavonoid research are widely conflicting, probably owing to inter- and intra-assay variation in susceptibility testing. However, several high-quality investigations have examined the relationship between flavonoid structure and antibacterial activity and these are in close agreement. In addition, numerous research groups have sought to elucidate the antibacterial mechanisms of action of selected flavonoids. The activity of quercetin, for example, has been at least partially attributed to inhibition of DNA gyrase. It has also been proposed that sophoraflavone G and (-)-epigallocatechin gallate inhibit cytoplasmic membrane function, and that licochalcones A and C inhibit energy metabolism. Other flavonoids whose mechanisms of action have been investigated include robinetin, myricetin, apigenin, rutin, galangin, 2,4,2'-trihydroxy-5'-methylchalcone and lonchocarpol A. These compounds represent novel leads, and future studies may allow the development of a pharmacologically acceptable antimicrobial agent or class of agents.

  16. Chitosan nanoparticles enhance the intestinal absorption of the green tea catechins (+)-catechin and (-)-epigallocatechin gallate.

    Science.gov (United States)

    Dube, Admire; Nicolazzo, Joseph A; Larson, Ian

    2010-10-09

    Catechins found in green tea have received considerable attention due to their favourable biological properties which include cardioprotective, neuroprotective and anti-cancer effects. However, their therapeutic potential is limited by their low oral bioavailability, attributed to poor stability and intestinal absorption. We encapsulated (+)-catechin (C) and (-)-epigallocatechin gallate (EGCg) in chitosan nanoparticles (CS NP) as a means of enhancing their intestinal absorption. Using excised mouse jejunum in Ussing chambers, encapsulation significantly enhanced (pcatechins after encapsulation (99.7+/-0.7 vs 94.9+/-3.8% and 56.9+/-3.0 vs 1.3+/-1.7% of the initial C and EGCg concentration remaining, respectively). This study demonstrates that encapsulation of catechins in CS NPs enhances their intestinal absorption and is a promising strategy for improving their bioavailability.

  17. Singlet oxygen reactions with flavonoids. A theoretical-experimental study.

    Directory of Open Access Journals (Sweden)

    Javier Morales

    Full Text Available Detection of singlet oxygen emission, λ(max = 1270 nm, following laser excitation and steady-state methods were employed to measure the total reaction rate constant, k(T, and the reactive reaction rate constant, k(r, for the reaction between singlet oxygen and several flavonoids. Values of k(T determined in deuterated water, ranging from 2.4×10(7 M(-1 s(-1 to 13.4×10(7 M(-1 s(-1, for rutin and morin, respectively, and the values measured for k(r, ranging from 2.8×10(5 M(-1 s(-1 to 65.7×10(5 M(-1 s(-1 for kaempferol and morin, respectively, being epicatechin and catechin chemically unreactive. These results indicate that all the studied flavonoids are good quenchers of singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid-rich diet was previously consumed. Analysis of the dependence of rate constant values with molecular structure in terms of global descriptors and condensed Fukui functions, resulting from electronic structure calculations, supports the formation of a charge transfer exciplex in all studied reactions. The fraction of exciplex giving reaction products evolves through a hydroperoxide and/or an endoperoxide intermediate produced by singlet oxygen attack on the double bond of the ring C of the flavonoid.

  18. Singlet Oxygen Reactions with Flavonoids. A Theoretical – Experimental Study

    Science.gov (United States)

    Morales, Javier; Günther, Germán; Zanocco, Antonio L.; Lemp, Else

    2012-01-01

    Detection of singlet oxygen emission, λmax = 1270 nm, following laser excitation and steady-state methods were employed to measure the total reaction rate constant, kT, and the reactive reaction rate constant, kr, for the reaction between singlet oxygen and several flavonoids. Values of kT determined in deuterated water, ranging from 2.4×107 M−1s−1 to 13.4×107 M−1s−1, for rutin and morin, respectively, and the values measured for kr, ranging from 2.8×105 M−1s−1 to 65.7×105 M−1s−1 for kaempferol and morin, respectively, being epicatechin and catechin chemically unreactive. These results indicate that all the studied flavonoids are good quenchers of singlet oxygen and could be valuable antioxidants in systems under oxidative stress, in particular if a flavonoid-rich diet was previously consumed. Analysis of the dependence of rate constant values with molecular structure in terms of global descriptors and condensed Fukui functions, resulting from electronic structure calculations, supports the formation of a charge transfer exciplex in all studied reactions. The fraction of exciplex giving reaction products evolves through a hydroperoxide and/or an endoperoxide intermediate produced by singlet oxygen attack on the double bond of the ring C of the flavonoid. PMID:22802966

  19. Flavonoids and the CNS

    Directory of Open Access Journals (Sweden)

    Anna K. Jäger

    2011-02-01

    Full Text Available Flavonoids are present in almost all terrestrial plants, where they provide UV-protection and colour. Flavonoids have a fused ring system consisting of an aromatic ring and a benzopyran ring with a phenyl substituent. The flavonoids can be divided into several classes depending on their structure. Flavonoids are present in food and medicinal plants and are thus consumed by humans. They are found in plants as glycosides. Before oral absorption, flavonoids undergo deglycosylation either by lactase phloridzin hydrolase or cytosolic β-glucocidase. The absorbed aglycone is then conjugated by methylation, sulphatation or glucuronidation. Both the aglycones and the conjugates can pass the blood-brain barrier. In the CNS several flavones bind to the benzodiazepine site on the GABAA-receptor resulting in sedation, anxiolytic or anti-convulsive effects. Flavonoids of several classes are inhibitors of monoamine oxidase A or B, thereby working as anti-depressants or to improve the conditions of Parkinson’s patients. Flavanols, flavanones and anthocyanidins have protective effects preventing inflammatory processes leading to nerve injury. Flavonoids seem capable of influencing health and mood.

  20. Protections of bovine serum albumin protein from damage on functionalized graphene-based electrodes by flavonoids

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Bolu [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China); Gou, Yuqiang [Lanzhou Military Command Center for Disease Prevention and Control, Lanzhou 730000 (China); Xue, Zhiyuan; Zheng, Xiaoping; Ma, Yuling [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China); Hu, Fangdi, E-mail: hufd@lzu.edu.cn [School of Pharmacy, Lanzhou University, Lanzhou 730000 (China); Zhao, Wanghong, E-mail: wanghongzhao@sina.com [Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou 51515 (China)

    2016-05-01

    A sensitive electrochemical sensor based on bovine serum albumin (BSA)/poly (diallyldimethylammonium chloride) (PDDA) functionalized graphene nanosheets (PDDA-G) composite film modified glassy carbon electrode (BSA/PDDA-G/GCE) had been developed to investigate the oxidative protein damage and protections of protein from damage by flavonoids. The performance of this sensor was remarkably improved due to excellent electrical conductivity, strong adsorptive ability, and large effective surface area of PDDA-G. The BSA/PDDA-G/GCE displayed the greatest degree of BSA oxidation damage at 40 min incubation time and in the pH 5.0 Fenton reagent system (12.5 mM FeSO{sub 4}, 50 mM H{sub 2}O{sub 2}). The antioxidant activities of four flavonoids had been compared by fabricated sensor based on the relative peak current ratio of SWV, because flavonoids prevented BSA damage caused by Fenton reagent and affected the BSA signal in a solution containing Co(bpy){sub 3}{sup 3+}. The sensor was characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). UV–vis spectrophotometry and FTIR were also used to investigate the generation of hydroxyl radical and BSA damage, respectively. On the basis of results from electrochemical methods, the order of the antioxidant activities of flavonoids is as follows: (+)-catechin > kaempferol > apigenin > naringenin. A novel, direct SWV analytical method for detection of BSA damage and assessment of the antioxidant activities of four flavonoids was developed and this electrochemical method provided a simple, inexpensive and rapid detection of BSA damage and evaluation of the antioxidant activities of samples. - Highlights: • Hydroxyl radicals were produced by Fenton reagents. • An electrochemical bovine serum albumin (BSA) damage sensor was successfully fabricated. • The proposed biosensor can assess the antioxidant capacity of four flavonoids. • The order of antioxidant

  1. Antimicrobial mechanism of flavonoids against Escherichia coli ATCC 25922 by model membrane study

    Energy Technology Data Exchange (ETDEWEB)

    He, Mengying; Wu, Ting; Pan, Siyi; Xu, Xiaoyun, E-mail: xiaoyunxu88@gmail.com

    2014-06-01

    Antimicrobial mechanism of four flavonoids (kaempferol, hesperitin, (+)-catechin hydrate, biochanin A) against Escherichia coli ATCC 25922 was investigated through cell membranes and a liposome model. The release of bacterial protein and images from transmission electron microscopy demonstrated damage to the E. coli ATCC 25922 membrane. A liposome model with dipalmitoylphosphatidylethanolamine (DPPE) (0.6 molar ratio) and dipalmitoylphosphatidylglycerol (DPPG) (0.4 molar ratio), representative of the phospholipid membrane of E. coli ATCC 25922, was used to specify the mode of action of four selected flavonoids through Raman spectroscopy and differential scanning calorimetry. It is suggested that for flavonoids, to be effective antimicrobials, interaction with the polar head-group of the model membrane followed by penetration into the hydrophobic regions must occur. The antimicrobial efficacies of the flavonoids were consistent with liposome interaction activities, kaempferol > hesperitin > (+)-catechin hydrate > biochanin A. This study provides a liposome model capable of mimicking the cell membrane of E. coli ATCC 25922. The findings are important in understanding the antibacterial mechanism on cell membranes.

  2. FLAVONOIDS FROM Cleome amblyocarpa

    OpenAIRE

    A. ULUBELEN*, N. TAN*, F.M. HARRAZ**,

    2015-01-01

    Seven flavonoids, six of them being known compounds, named apigenin, kaempferol 3-glucoside, quercetin 3-glucoside-7-rhamnoside,is orhamnetin 3- glucoside-7-rhamnoside, kaempferol 3, 7-dirhamnoside, kaempferol7-rhamnoside and the new derivative of kaempferol: kaempferol 7-methyl ether 3-rhamnoside were obtained from the polar fractions of Cleome amblyocarpa. Their structures were determined by spectral and chemical methods.Key words: Cleome arnblyocarpa; Capparaceae; flavonoids.

  3. Synthesis, characterization and in vitro anti-diabetic activity of catechin grafted inulin.

    Science.gov (United States)

    Liu, Jun; Lu, Jian-feng; Kan, Juan; Wen, Xiao-yuan; Jin, Chang-hai

    2014-03-01

    In this study, a novel biological macromolecule with strong in vitro anti-diabetic activity was developed by grafting catechin onto inulin via a free radical mediated method. The characterization, α-glucosidase and α-amylase inhibitory activities of catechin grafted inulin (catechin-g-inulin) were investigated. Results showed that the grafting ratio of catechin-g-inulin was 124.8 mg CAE/g. UV-vis spectrum of catechin-g-inulin exhibited a new band at 280 nm, attributing to B ring of catechin moiety. FT-IR spectrum of catechin-g-inulin showed new absorption bands between 1540 and 1418 cm(-1), attributing to CC stretching vibration of catechin moiety. (1)H NMR spectrum of catechin-g-inulin preserved all the characteristic proton signals of inulin and partial signals of catechin. These all confirmed the successful grafting copolymerization. Conjugation probably occurred between OH of inulin (C-6) and H-6/H-8 of catechin (A ring). Catechin-g-inulin also exhibited increased thermal stability and crystallinity as compared to inulin. Moreover, in vitro anti-diabetic assays showed the α-glucosidase inhibitory activity decreased in the order of catechin-g-inulin>catechin>acarbose>inulin, and α-amylase inhibitory activity decreased in the order of catechin-g-inulin>acarbose>catechin>inulin. These indicated the potential of catechin-g-inulin in the development of a novel effective anti-diabetic agent.

  4. Sweeteners - sugars

    Science.gov (United States)

    ... vitamin-type" waters, sports drinks, coffee drinks, and energy drinks also contain a lot of added sugar. ... vitamin-type" water, sports drinks, coffee drinks, and energy drinks. Eat less candy and sweet desserts such as ...

  5. Metabolic Flux Redirection and Transcriptomic Reprogramming in the Albino Tea Cultivar ‘Yu-Jin-Xiang’ with an Emphasis on Catechin Production

    Science.gov (United States)

    Liu, Guo-Feng; Han, Zhuo-Xiao; Feng, Lin; Gao, Li-Ping; Gao, Ming-Jun; Gruber, Margaret Y.; Zhang, Zhao-Liang; Xia, Tao; Wan, Xiao-Chun; Wei, Shu

    2017-01-01

    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. Metabolic flux redirection and transcriptomic reprogramming were found in flavonoid and carotenoid pathways of the ‘YJX’ pale leaves and shaded green leaves to different extents compared to the green cultivar ‘Shu-Cha-Zao’. Enhanced production of the antioxidant quercetin rather than catechin biosynthesis was correlated positively with the enhanced transcription of FLAVONOL SYNTHASE and FLAVANONE/FLAVONOL HYDROXYLASES leading to quercetin accumulation and negatively correlated to suppressed LEUCOANTHOCYANIDIN REDUCTASE, ANTHOCYANIDIN REDUCTASE and SYNTHASE leading to catechin biosynthesis. The altered levels of quercetin and catechins in ‘YJX’ will impact on its tea flavor and health benefits. PMID:28332598

  6. Metabolic Flux Redirection and Transcriptomic Reprogramming in the Albino Tea Cultivar 'Yu-Jin-Xiang' with an Emphasis on Catechin Production.

    Science.gov (United States)

    Liu, Guo-Feng; Han, Zhuo-Xiao; Feng, Lin; Gao, Li-Ping; Gao, Ming-Jun; Gruber, Margaret Y; Zhang, Zhao-Liang; Xia, Tao; Wan, Xiao-Chun; Wei, Shu

    2017-03-23

    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. Metabolic flux redirection and transcriptomic reprogramming were found in flavonoid and carotenoid pathways of the 'YJX' pale leaves and shaded green leaves to different extents compared to the green cultivar 'Shu-Cha-Zao'. Enhanced production of the antioxidant quercetin rather than catechin biosynthesis was correlated positively with the enhanced transcription of FLAVONOL SYNTHASE and FLAVANONE/FLAVONOL HYDROXYLASES leading to quercetin accumulation and negatively correlated to suppressed LEUCOANTHOCYANIDIN REDUCTASE, ANTHOCYANIDIN REDUCTASE and SYNTHASE leading to catechin biosynthesis. The altered levels of quercetin and catechins in 'YJX' will impact on its tea flavor and health benefits.

  7. Separation and Identification of Flavonoids from Fistular Onion Stalk(Allium fisturosum L.var.Caespitosum Makio)

    Institute of Scientific and Technical Information of China (English)

    付琴琴; 刘静幽; 张长弓; 周银波; 张耕; 马丹; 杨新洲

    2010-01-01

    The chemical constituents of fistular onion stalk obtained by supercritical CO2 extraction were separated and purified by silica gel and sephadex LH-20 gel column chromatography and the preparative TLC method and four flavonoids were obtained.On the basis of the spectral data,they were structurally identified as(+)-catechin,(-)-epicatechin,astragalin,and 3-O-β-D(2-O-β-D-glucopyranosyl)-glucopyranosides of kaempferol.

  8. Neuroprotection by flavonoids

    Directory of Open Access Journals (Sweden)

    Dajas F.

    2003-01-01

    Full Text Available The high morbidity, high socioeconomic costs and lack of specific treatments are key factors that define the relevance of brain pathology for human health and the importance of research on neuronal protective agents. Epidemiological studies have shown beneficial effects of flavonoids on arteriosclerosis-related pathology in general and neurodegeneration in particular. Flavonoids can protect the brain by their ability to modulate intracellular signals promoting cellular survival. Quercetin and structurally related flavonoids (myricetin, fisetin, luteolin showed a marked cytoprotective capacity in in vitro experimental conditions in models of predominantly apoptotic death such as that induced by medium concentrations (200 µM of H2O2 added to PC12 cells in culture. Nevertheless, quercetin did not protect substantia nigra neurons in vivo from an oxidative insult (6-hydroxydopamine, probably due to difficulties in crossing the blood-brain barrier. On the other hand, treatment of permanent focal ischemia with a lecithin/quercetin preparation decreased lesion volume, showing that preparations that help to cross the blood-brain barrier may be critical for the expression of the effects of flavonoids on the brain. The hypothesis is advanced that a group of quercetin-related flavonoids could become lead molecules for the development of neuroprotective compounds with multitarget anti-ischemic effects.

  9. Catechins and Their Therapeutic Benefits to Inflammatory Bowel Disease

    Directory of Open Access Journals (Sweden)

    Fei-Yan Fan

    2017-03-01

    Full Text Available Catechins are natural polyphenolic phytochemicals that exist in food and medicinal plants, such as tea, legume and rubiaceae. An increasing number of studies have associated the intake of catechins-rich foods with the prevention and treatment of chronic diseases in humans, such as inflammatory bowel disease (IBD. Some studies have demonstrated that catechins could significantly inhibit the excessive oxidative stress through direct or indirect antioxidant effects and promote the activation of the antioxidative substances such as glutathione peroxidases (GPO and glutathione (GSH, reducing the oxidative damages to the colon. In addition, catechins can also regulate the infiltration and proliferation of immune related-cells, such as neutrophils, colonic epithelial cells, macrophages, and T lymphocytes, helping reduce the inflammatory relations and provide benefits to IBD. Perhaps catechins can further inhibit the deterioration of intestinal lesions through regulating the cell gap junctions. Furthermore, catechins can exert their significant anti-inflammatory properties by regulating the activation or deactivation of inflammation-related oxidative stress-related cell signaling pathways, such as nuclear factor-kappa B (NF-κB, mitogen activated protein kinases (MAPKs, transcription factor nuclear factor (erythroid-derived 2-like 2 (Nrf2, signal transducer and the activator of transcription 1/3 (STAT1/3 pathways. Finally, catechins can also stabilize the structure of the gastrointestinal micro-ecological environment via promoting the proliferation of beneficial intestinal bacteria and regulating the balance of intestinal flora, so as to relieve the IBD. Furthermore, catechins may regulate the tight junctions (TJ in the epithelium. This paper elaborates the currently known possible molecular mechanisms of catechins in favor of IBD.

  10. Development of novel monoclonal antibodies directed against catechins for investigation of antibacterial mechanism of catechins.

    Science.gov (United States)

    Miyamoto, Takahisa; Zhang, Xiaoguang; Ueyama, Yuuki; Apisada, Kitichalermkiat; Nakayama, Motokazu; Suzuki, Yasuto; Ozawa, Tadahiro; Mitani, Asako; Shigemune, Naofumi; Shimatani, Kanami; Yui, Koji; Honjoh, Ken-Ichi

    2017-03-24

    Catechins are major polyphenolic compounds of green tea. To investigate mechanism for antibacterial action of catechins, 11 monoclonal antibodies (MAbs) were raised against a 3-succinyl-epicatechin (EC)-keyhole limpet hemocyanin (KLH) conjugate. Amino acid sequences of variable regions determined for MAbs b-1058, b-1565, and b-2106 confirmed their innovative character. MAb b-1058 strongly interacted with its target substances in the following order of magnitude: theaflavin-3,3'-di-O-gallate (TFDG)>theaflavin-3-O-gallate (TF3G)≥theaflavin-3'-O-gallate (TF3'G)>gallocatechin gallate (GCg)>penta-O-galloyl-β-d-glucose (PGG)>epigallocatechin gallate (EGCg), as determined using surface plasmon resonance (SPR) on MAb-immobilized sensor chips. The affinity profiles of MAbs b-1058 and b-2106 to the various polyphenols tested suggested that flavan skeletons with both carbonyl oxygen and hydroxyl groups are important for this interaction to take place. S. aureus cells treated with EGCg showed green fluorescence around the cells after incubation with FITC-labeled MAb b-1058. The fluorescence intensity increased with increasing concentrations of EGCg. These MAbs are effective to investigate antibacterial mechanism of catechins and theaflavins.

  11. Suppressive Effects of Tea Catechins on Breast Cancer.

    Science.gov (United States)

    Xiang, Li-Ping; Wang, Ao; Ye, Jian-Hui; Zheng, Xin-Qiang; Polito, Curt Anthony; Lu, Jian-Liang; Li, Qing-Sheng; Liang, Yue-Rong

    2016-07-28

    Tea leaf (Camellia sinensis) is rich in catechins, which endow tea with various health benefits. There are more than ten catechin compounds in tea, among which epigallocatechingallate (EGCG) is the most abundant. Epidemiological studies on the association between tea consumption and the risk of breast cancer were summarized, and the inhibitory effects of tea catechins on breast cancer, with EGCG as a representative compound, were reviewed in the present paper. The controversial results regarding the role of tea in breast cancer and areas for further study were discussed.

  12. Purification of Flavonoids from Black Currant Juice by Nanodiafiltration

    DEFF Research Database (Denmark)

    Jensen, Morten Busch; Christensen, Knud Villy; Norddahl, Birgir

    2009-01-01

    from the flavonoids in order to facilitate better analysis.         In the current study, the major solutes in black currant juice are fructose (32 ± 3 g/l), glucose (22 ± 3 g/l), sucrose (1.6 ± 0.2 g/l) and organic acids (28.9 ± 0.1 g/l). The flavonoids in black currant juice are mainly (97......%) comprised by the glucosides and rutinosides of cyanidin and delphinidin [2]. The content of these flavonoids in black currant juice is measured to (1.5 ± 0.1 g/l). The separation process consists of nanodiafiltration on flat sheet membranes with a nominal molecular weight cut off of 1,000 Da. The separation...... process was monitored by comparing concentrations of the four flavonoids and the sugars and acids in permeate and retentate. The flavonoids in the juice have a molecular weight between 449 and 611 Da and should be able to pass the pores of the membrane. However this study shows that the flavonoids...

  13. Quantitative and Qualitative analysis of Phenolic and Flavonoid content in Moringa oleifera Lam and Ocimum tenuiflorum L.

    Directory of Open Access Journals (Sweden)

    Sangeeta Sankhalkar

    2016-01-01

    Full Text Available Background: Number of secondary compounds is produced by plants as natural antioxidants. Moringa oleifera Lam. and Ocimum tenuiflorum L. are known for their wide applications in food and pharmaceutical industry. Objective: To compare phenolic and flavonoid content in M. oleifera Lam and O. tenuiflorum L. by quantitative and qualitative analysis. Materials and Methods: Phenolic and flavonoid content were studied spectrophotometrically and by paper chromatography in M. oleifera Lam. and O. tenuiflorum L. Results: Higher phenolic and flavonoid content were observed in Moringa leaf and flower. Ocimum flower showed higher phenolic content and low flavonoid in comparison to Moringa. Flavonoids such as biflavonyl, flavones, glycosylflavones, and kaempferol were identified by paper chromatography. Phytochemical analysis for flavonoid, tannins, saponins, alkaloids, reducing sugars, and anthraquinones were tested positive for Moringa and Ocimum leaf as well as flower. Conclusions: In the present study higher phenolic and flavonoid content, indicated the natural antioxidant nature of Moringa and Ocimum signifying their medicinal importance.

  14. Dietary flavonoids and iodine Metabolism

    NARCIS (Netherlands)

    Elst, van der J.P.; Smit, J.W.A.; Romijn, H.A.; Heide, van der D.

    2003-01-01

    Flavonoids have inhibiting effects on the proliferation of cancer cells, including thyroidal ones. In the treatment of thyroid cancer the uptake of iodide is essential. Flavonoids are known to interfere with iodide organification ill vitro, and to cause goiter. The influence of flavonoids on iodine

  15. Molecular interactions between caffeine and catechins in green tea.

    Science.gov (United States)

    Colon, Marta; Nerin, Cristina

    2014-07-16

    Migration of green tea components from an active packaging material containing green tea extract was performed in water and 3% acetic acid in water. The migration values for acid simulant were much higher than the values obtained in water. The influence of the acidic media in solutions of catechin standards and green tea extract was evaluated by liquid chromatography. Catechin, epicatechin, and caffeine from the green tea extract exhibited major variation in their concentrations values, with increases of 29.90, 20.75, and 15.95%, respectively, in acidic medium. The results suggested that catechins and caffeine form complexes through intermolecular interactions in neutral media and that these interactions are broken in acidic media. The continuous variation method was also performed to confirm the stoichiometry of the complexes between catechins and caffeine. Finally, a computer simulation was applied by Chem Pro 12.0, and the energies involved were calculated to confirm the experimental results obtained.

  16. Examining the potential benefits of (--epicatechin, (+-catechin, and rutin on maternal and offspring cardiovascular outcomes in LDLr-/-mice exposed to an atherogenic environment during early development

    Directory of Open Access Journals (Sweden)

    Mary N. R. Lesser

    2016-04-01

    Full Text Available Background: Maternal nutritional status can impact numerous early developmental processes. In certain cases, these effects can influence the risk their off spring can have for select chronic diseases later in life. Consequently, in this article were port on the effects of maternal consumption of high levels of certain flavonoids on the development of coronary artery disease (CAD in an atherosclerosis-prone mutant mouse model.Methods:LDLr -/-mutant mice were fed a control fat (CF, high fat (HF, or the HFdiet supplemented with epicatechin and catechin (HFEC or rutin (HFRU, prior to pregnancy and during lactation, in order to explore whether the flavonoids influenced markers of vascular health in the lactating dams (lactation day (LD 21. Post-weaning (postnatal day(PND22, offspring were challenged with an atherogenic environment (HF diet in the absence of flavonoids and vascular health markers were assessed in the adult offspring (PND 60. Results:Dams fed the HF diet had elevated markers of atherosclerosisonLD 21whencompared to the dams fed with the control diet. Flavonoid consumption prior to pregnancy and during lactation had inconsistent effects on maternal markers of atherosclerosis (plasma cholesterol, aortic lipid accumulation, and oxidative stress biomarkers at LD21 compared to dams fed the HF diet without flavonoids.At PND 60, there were no differences in vascular health markers among the groups of LDLr -/-offspring whose mothers consumed the CF or the HF diet with or without flavonoids during lactation. Conclusions: Maternal consumption of the flavonoid-supplemented HF diets had modest effects on maternal markers of atherosclerosis. The exposure of offspring to the flavonoid-supplemented HF diets during early lactation had little effect on the cardiovascular parameters assessed in the adult offspring.

  17. Managing your blood sugar

    Science.gov (United States)

    Hyperglycemia - control; Hypoglycemia - control; Diabetes - blood sugar control; Blood glucose - managing ... Know how to: Recognize and treat low blood sugar ( hypoglycemia ) Recognize and treat high blood sugar ( hyperglycemia ) ...

  18. Flavonoids from Inula viscosa.

    Science.gov (United States)

    Grande, M; Piera, F; Cuenca, A; Torres, P; Bellido, I S

    1985-10-01

    Phytochemical study of the aerial parts of INULA VISCOSA resulted in the isolation of sixteen flavonoids. One of them, 3- O-acetylpadmatin [(2 R,3 R)-3-acetoxy-5,3',4'-trihydroxy-7-methoxyflavanone], was isolated for the first time as a natural compound. Ferulic aldehyde, 2-methylphloroacetophenone, inuviscolide and 2-deacetoxyxanthinin were also isolated.

  19. Flavonoids and thyroid disease

    NARCIS (Netherlands)

    Heide, van der D.; Kastelijn, J.; Schroder-van der Elst, J.P.

    2003-01-01

    The most potent natural plant-derived compounds that can affect thyroid function, thyroid hormone secretion and availability to tissues is the group of flavonoids, i.e. plant pigments. They are present in our daily food, such as vegetables, fruits, grains, nuts, wine, and tea. Epidemiological studie

  20. Flavonoids from Carthamus tinctorius

    Institute of Scientific and Technical Information of China (English)

    LI,Feng(李锋); HE,Zhi-Sheng(何直昇); YE,Yang(叶阳)

    2002-01-01

    Two new flavonoids, (2S)-4' ,5-dihydroxyl-6,7-di-O-β-D-glucopyranosyl flavanone (1) and 6-hydroxykaempferol 6,7-di-O-β-D-glucopyranoside (2), were isolated from Carthamus tinctorius. Their structures were elucidated by spectroscopic means including 2D NMR, ESIMS and CD.

  1. Flavonoids in Astragalus corniculatus

    Directory of Open Access Journals (Sweden)

    Ilina Krasteva

    2008-01-01

    Full Text Available Nine flavonoids were identified in aerial parts of Astragalus corniculatus Bieb. (Fabaceae by liquid chromatography coupled with ionspray mass spectrometry in the tandem mode (LC/MS/MS with negative ion detection. Vitexin, orientin and eriodictyol-7-O-glucoside are obtained for the first time in genus Astragalus L, and isorhamnetin-3-O-glucoside in the species.

  2. Flavonoids and the CNS

    DEFF Research Database (Denmark)

    Jäger, Anna Katharina; Saaby, Lasse

    2011-01-01

    , sulphatation or glucuronidation. Both the aglycones and the conjugates can pass the blood-brain barrier. In the CNS several flavones bind to the benzodiazepine site on the GABA(A)-receptor resulting in sedation, anxiolytic or anti-convulsive effects. Flavonoids of several classes are inhibitors of monoamine...

  3. Green tea (Camellia sinensis) catechins and vascular function.

    Science.gov (United States)

    Moore, Rosalind J; Jackson, Kim G; Minihane, Anne M

    2009-12-01

    The health benefits of green tea (Camellia sinensis) catechins are becoming increasingly recognised. Amongst the proposed benefits are the maintenance of endothelial function and vascular homeostasis and an associated reduction in atherogenesis and CVD risk. The mounting evidence for the influential effect of green tea catechins on vascular function from epidemiological, human intervention and animal studies is subject to review together with exploration of the potential mechanistic pathways involved. Epigallocatechin-3-gallate, one of the most abundant and widely studied catechin found in green tea, will be prominent in the present review. Since there is a substantial inconsistency in the published data with regards to the impact of green tea catechins on vascular function, evaluation and interpretation of the inter- and intra-study variability is included. In conclusion, a positive effect of green tea catechins on vascular function is becoming apparent. Further studies in animal and cell models using physiological concentrations of catechins and their metabolites are warranted in order to gain some insight into the physiology and molecular basis of the observed beneficial effects.

  4. Studies on the Interaction between Catechin and Metal Ions

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Jieun; Yang, Ikjun; Park, Okhyun; Park, Hyoungryun [Chonnam National Univ., Gwangju (Korea, Republic of); Bark, Kimin [Gyeongsang National Univ., Chinju (Korea, Republic of); Park, Chulho [Nambu Univ., Gwangju (Korea, Republic of)

    2012-12-15

    In conclusion, the UV-vis absorption spectra of the deaerated methanolic solution reacted with metal ions such as Cu{sup 2+}, Zn{sup 2+}, Co{sup 2+}, and Fe{sup 3+} were changed as time passed after adding catechin followed by addition of catechin to methanol. This is strongly dependent not only on the presence of metal ion but on the storage time of the solution. The change has relevance to the oxidation of catechin. Oxidation of catechin is first initiated by the dissociation of -OH part of the catechol moiety in methanol and then the ionized anion forms are converted into their oxidized forms called quinones. The higher the standard reduction potential for metal-ion, the faster the oxidation occurs. The steady-state fluorescence emission spectra of catechin changed depending on the storage time of the solution. This finding indicates that oxidation of catechin is undergone by a sequence of multistep reactions in deaerated methanol solution.

  5. Miniaturized molecularly imprinted polymer extraction method for the gas chromatographic analysis of flavonoids.

    Science.gov (United States)

    Nolvachai, Yada; Kulsing, Chadin; Boysen, Reinhard I; Hearn, Milton T W; Marriott, Philip J

    2014-04-01

    In this study, the use of monolithic molecularly imprinted polymers in a micropipette tip format allowing the simple and fast extraction of flavonoids from standard solutions and a black tea sample is demonstrated. The imprinted polymer employed quercetin, methacrylic acid or 4-vinylpyridine, and ethylene glycol dimethacrylate as template, functional monomer, and cross-linker, respectively. Surface morphologies of the quercetin-imprinted polymers and the corresponding nonimprinted polymers were characterized by SEM. Extraction of flavonoid standards was performed to evaluate the selectivity and recovery with these imprinted and nonimprinted polymers. Flavonoid compositions in aliquots eluted from the tips were identified using fast GC with flame ionization detection. Maximum specific capacities of 0.2, 5.7, and 16.0 mg/g for catechin, morin, and quercetin, respectively, were obtained with the imprinted polymer prepared with methacrylic acid, with the corresponding recoveries of 99.8, 98.8, and 95.4%, respectively. Efficient extraction by the quercetin-imprinted polymer of epicatechin, catechin, and quercetin from an apple-flavored black tea sample was achieved, with GC-MS employed for compound identification for both the tea and extracted samples.

  6. Structural characteristics of green tea catechins for formation of protein carbonyl in human serum albumin.

    Science.gov (United States)

    Ishii, Takeshi; Mori, Taiki; Ichikawa, Tatsuya; Kaku, Maiko; Kusaka, Koji; Uekusa, Yoshinori; Akagawa, Mitsugu; Aihara, Yoshiyuki; Furuta, Takumi; Wakimoto, Toshiyuki; Kan, Toshiyuki; Nakayama, Tsutomu

    2010-07-15

    Catechins are polyphenolic antioxidants found in green tea leaves. Recent studies have reported that various polyphenolic compounds, including catechins, cause protein carbonyl formation in proteins via their pro-oxidant actions. In this study, we evaluate the formation of protein carbonyl in human serum albumin (HSA) by tea catechins and investigate the relationship between catechin chemical structure and its pro-oxidant property. To assess the formation of protein carbonyl in HSA, HSA was incubated with four individual catechins under physiological conditions to generate biotin-LC-hydrazide labeled protein carbonyls. Comparison of catechins using Western blotting revealed that the formation of protein carbonyl in HSA was higher for pyrogallol-type catechins than the corresponding catechol-type catechins. In addition, the formation of protein carbonyl was also found to be higher for the catechins having a galloyl group than the corresponding catechins lacking a galloyl group. The importance of the pyrogallol structural motif in the B-ring and the galloyl group was confirmed using methylated catechins and phenolic acids. These results indicate that the most important structural element contributing to the formation of protein carbonyl in HSA by tea catechins is the pyrogallol structural motif in the B-ring, followed by the galloyl group. The oxidation stability and binding affinity of tea catechins with proteins are responsible for the formation of protein carbonyl, and consequently the difference in these properties of each catechin may contribute to the magnitude of their biological activities.

  7. Flavonoids from flowers of Cephalaria pastricensis and their antiradical activity

    Directory of Open Access Journals (Sweden)

    SLOBODAN MILOSAVLJEVIC

    2004-11-01

    Full Text Available Two flavonoid glycosides 1 and 2 having the luteolin structure were isolated from flowers of the endemic plant species Cephalaria pastricensis. They were identified by 1H and 13C NMR, as well as UV/Vis spectroscopy. The structures of 1 and 2 were also confirmed by the spectral data of aglycones and TLC of the sugars obtained after acid hydrolysis. Flavones 1 and 2 showed significant antiradical activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH assay.

  8. Quercetin: a versatile flavonoid

    Directory of Open Access Journals (Sweden)

    Dr. Deepak Kumar Rai

    2007-07-01

    Full Text Available Associative evidence from observational and intervention studies in human subjects shows that a diet including plant foods (particularly fruit and vegetables rich in antioxidants conveys health benefits. There is no evidence that any particular nutrient or class of bioactive substances makes a special contribution to these benefits. Flavonoids occur naturally in fruits, vegetables and beverages such as tea and wine. Quercetin is the major flavonoid which belongs to the class called flavonols. Quercetin is found in many common foods including apples, tea, onions, nuts, berries, cauliflower, cabbage and many other foods. Quercetin provides many health promoting benefits, including improvement of cardiovascular health, eye diseases, allergic disorders, arthritis, reducing risk for cancers and many more. The main aim of this review is to obtain a further understanding of the reported beneficial health effects of Quercetin, its pharmacological effects, clinical application and also to evaluate its safety.

  9. Protective Properties of Flavonoid Extract of Coagulated Tofu (Curdled Soy Milk Against Acetaminophen-Induced Liver Injury in Rats

    Directory of Open Access Journals (Sweden)

    Ndatsu Yakubu

    2016-01-01

    Full Text Available The total flavonoid contents of the various coagulated tofu and the hepatoprotective potential of all tofu flavonoid extracts were investigated. Tofu was prepared from locally sourced coagulants (steep water, alum, lemon, and lemon peel ash extract. Total flavonoid contents of all coagulated tofu were investigated as established in vitro flavonoid assay. The hepatoprotective activities of tofu flavonoid extracts against acetaminophen-induced hepatic cell toxicity in rats was also investigated in this study. The activity was analyzed by assessing the levels of serum alanine aminotransferase (ALT, aspartate aminotransferase (AST, alkaline phosphatase (ALP and lactate dehydrogenase (LDH. The concentrations of the serum sugar, total protein, albumin, and cholesterol as well as prothrombin time (PT of experimental rats with histopathological analysis were also conducted. The range of the total flavonoid contents of tofu was 4.3-6.4 mg/g. Tofu flavonoid extracts significantly reduced the activities of serum AST, ALT, ALP, and LDH; total cholesterol, and sugar levels, but total protein and albumin concentrations increased compared to acetaminophen-intoxicated rats. Also, the prothrombin time prolongation of serum in acetaminophen intoxicated rats was reduced. Histology of the liver tissue demonstrated that tofu flavonoid extracts inhibited the acetaminophen-induced hepatic cell necrosis, decreased inflammatory cell infiltration and accelerated hepatocellular regeneration. Therefore, all tofus exhibited high total flavonoid contents, and the tofu supplement in human diets is highly recommended as it can be used as a functional food to prevent liver injuries.

  10. Effects of Flavonoids from Food and Dietary Supplements on Glial and Glioblastoma Multiforme Cells.

    Science.gov (United States)

    Vidak, Marko; Rozman, Damjana; Komel, Radovan

    2015-10-23

    Quercetin, catechins and proanthocyanidins are flavonoids that are prominently featured in foodstuffs and dietary supplements, and may possess anti-carcinogenic activity. Glioblastoma multiforme is the most dangerous form of glioma, a malignancy of the brain connective tissue. This review assesses molecular structures of these flavonoids, their importance as components of diet and dietary supplements, their bioavailability and ability to cross the blood-brain barrier, their reported beneficial health effects, and their effects on non-malignant glial as well as glioblastoma tumor cells. The reviewed flavonoids appear to protect glial cells via reduction of oxidative stress, while some also attenuate glutamate-induced excitotoxicity and reduce neuroinflammation. Most of the reviewed flavonoids inhibit proliferation of glioblastoma cells and induce their death. Moreover, some of them inhibit pro-oncogene signaling pathways and intensify the effect of conventional anti-cancer therapies. However, most of these anti-glioblastoma effects have only been observed in vitro or in animal models. Due to limited ability of the reviewed flavonoids to access the brain, their normal dietary intake is likely insufficient to produce significant anti-cancer effects in this organ, and supplementation is needed.

  11. Antioxidant Capacity of Flavonoids in Hepatic Microsomes Is not Reflected by Antioxidant Effects In Vivo

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    Garry Duthie

    2012-01-01

    Full Text Available Flavonoids are polyphenolic compounds with potential antioxidant activity via multiple reduction capacities. Oxidation of cellular lipids has been implicated in many diseases. Consequently, this study has assessed the ability of several dietary flavonoid aglycones to suppress lipid peroxidation of hepatic microsomes derived from rats deficient in the major lipid soluble antioxidant, dα-tocopherol. Antioxidant effectiveness was galangin > quercetin > kaempferol > fisetin > myricetin > morin > catechin > apigenin. However, none of the flavonoids were as effective as dα-tocopherol, particularly at the lowest concentrations used. In addition, there appears to be an important distinction between the in vitro antioxidant effectiveness of flavonoids and their ability to suppress indices of oxidation in vivo. Compared with dα-tocopherol, repletion of vitamin E deficient rats with quercetin, kaempferol, or myricetin did not significantly affect indices of lipid peroxidation and tissue damage. Direct antioxidant effect of flavonoids in vivo was not apparent probably due to low bioavailability although indirect redox effects through stimulation of the antioxidant response element cannot be excluded.

  12. Flavonoid analysis of buckwheat sprouts.

    Science.gov (United States)

    Nam, Tae-Gyu; Lee, Sun Mi; Park, Ji-Hae; Kim, Dae-Ok; Baek, Nam-in; Eom, Seok Hyun

    2015-03-01

    It is known that common buckwheat sprouts contain several flavonoids, including orientin, isoorientin, vitexin, isovitexin, rutin, and quercetrin, whereas tartary buckwheat sprouts contain only rutin. In this study, we evaluated flavonoids present in buckwheat sprouts and identified a previously unreported flavonoid. Simultaneous detection by HPLC was used to separate rutin and a compound that was not separated in previous studies. We used a novel HPLC elution gradient method to successfully separate rutin and the previously unidentified compound, for which we performed structural analysis. The identification of six flavonoids by HPLC was confirmed using HPLC-ESI-MS/MS analysis. The newly identified compound, [M+H](+) =611.17, was identified by NMR as the rutin epimer quercetin-3-O-robinobioside. Unlike common buckwheat sprout, tartary buckwheat sprout contained rutin as a main flavonoid, whereas other flavonoids appeared only in trace amounts or were not detected. Quercetin-3-O-robinobioside was not detected in tartary buckwheat sprout.

  13. Flavonoid engineering of flax potentiate its biotechnological application

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    Prescha Anna

    2011-01-01

    Full Text Available Abstract Background Flavonoids are a group of secondary plant metabolites important for plant growth and development. They show also a protective effect against colon and breast cancer, diabetes, hypercholesterolemic atherosclerosis, lupus nephritis, and immune and inflammatory reactions. Thus, overproduction of these compounds in flax by genetic engineering method might potentiate biotechnological application of these plant products. Results Flax plants of third generation overexpressing key genes of flavonoid pathway cultivated in field were used as plant material throughout this study. The biochemical properties of seed, oil and seedcake extracts and fibre from natural and transgenic flax plants were compared. The data obtained suggests that the introduced genes were stably inherited and expressed through plant generations. Overproduction of flavonoid compounds resulted in increase of fatty acids accumulation in oil from transgenic seeds due to protection from oxidation offered during synthesis and seed maturation. The biochemical analysis of seedcake extracts from seeds of transgenic flax revealed significant increase in flavonoids (kaempferol, phenolic acids (coumaric, ferulic, synapic acids and lignan content. Fibres, another product of flax plant showed increase in the level of catechine and acetylvanillone and decrease in phenolic acids upon flax modification. Biochemical analysis results were confirmed using IR spectroscopy. The integral intensities of IR bands have been used for identification of the component of phenylpropanoid pathway in oil, seedcake extract and fibre from control and transgenic flax. It was shown that levels of flavonoids, phenolic acids and lignans in oil and seedcake extract was higher in transgenic flax products compared to control. An FT-IR study of fibres confirmed the biochemical data and revealed that the arrangement of the cellulose polymer in the transgenic fibres differs from the control; in particular a

  14. Effects of green tea catechins on gramicidin channel function and inferred changes in bilayer properties

    NARCIS (Netherlands)

    Ingólfsson, Helgi I; Koeppe, Roger E; Andersen, Olaf S

    2011-01-01

    Green tea's health benefits have been attributed to its major polyphenols, the catechins: (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), and epicatechin (EC). Catechins (especially EGCG) modulate a wide range of biologically important molecules, inclu

  15. The interactions of anticancer agents with tea catechins: current evidence from preclinical studies.

    Science.gov (United States)

    Shang, Weihu; Lu, Weidong; Han, Mei; Qiao, Jinping

    2014-01-01

    Tea catechins exhibit a broad range of pharmacological activities that impart beneficial effects on human health. Epigallocatechin-3-gallate (EGCG), one of the major tea catechins, has been widely associated with cancer prevention and treatment. In addition, tea catechins in combination with anticancer drugs are being evaluated as a new cancer treatment strategy. However, the interactions of anticancer drugs with tea catechins are largely unknown. Accumulated data indicate significant interactions between anticancer drugs and tea catechins, such as synergistic tumor inhibition or antagonist activity. Therefore, it is critical to understand comprehensively the effects of tea catechins on anticancer drugs. Focusing on evidence from preclinical studies, this paper will review the interactions between anticancer drugs and tea catechins, including pharmacodynamics and pharmacokinetics effects. We hope that by detailing the interactions between anticancer drugs and tea catechins, more attention will be directed to this important therapeutic combination in the future.

  16. Catechins decrease neurological severity score through apoptosis and neurotropic factor pathway in rat traumatic brain injury

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    Retty Ratnawati

    2017-08-01

    Administration of catechins decreased NSS through inhibiting inflammation and apoptosis, as well as induced the neurotrophic factors in rat brain injury. Catechins may serve as a potential intervention for TBI.

  17. Improved amine spray reagent for the detection of sugars

    NARCIS (Netherlands)

    Niemann, G.J.

    1979-01-01

    In the course of our investigations on naturally occurring flavonoid glycosides, the sugars obtained after acid hydrolysis were mainly analysed by gas-liquid chromatography and/or paper chromatography, using p-anisidine phosphate as the spray reagent. Often only very small amounts of the isolated co

  18. Subcellular Localization of Galloylated Catechins in Tea Plants [Camellia sinensis (L.) O. Kuntze] Assessed via Immunohistochemistry

    OpenAIRE

    Xu, Huanhuan; Wang, Ya; Chen, Yana; Zhang, Pan; Zhao, Yi; Huang, Yewei; Wang, Xuanjun; Sheng, Jun

    2016-01-01

    Galloylated catechins, as the main secondary metabolites in the tea plant, including (-)-epigallocatechin-3-gallate and (-)-epicatechin-3-gallate, comprise approximately three-quarters of all the tea plant catechins and have stronger effects than non-galloylated catechins, both on the product quality in tea processing and the pharmacological efficacy to human beings. The subcellular localization of galloylated catechins has been the primary focus of studies that assess biosynthesis and physio...

  19. Lipopolysaccharide-Deficient Mutants of Salmonella enterica Have Increased Sensitivity to Catechins

    OpenAIRE

    Yoshii, Miho; OKAMOTO, Akira; Ota, Michio

    2013-01-01

    Antimicrobial activity is one of the well-known biological characteristics of catechins, the main extract of green tea leaves. It is thought that catechins intercalate into the bacterial cell membrane and damage the lipid bilayer. However, the association between catechins and lipopolysaccharides, which consist of an O side chain, core oligosaccharide, and lipid A, has not been previously investigated. In this study, we evaluated the catechin sensitivity of Salmonella enterica mutants that la...

  20. Accumulation of catechins in tea in relation to accumulation of mRNA from genes involved in catechin biosynthesis.

    Science.gov (United States)

    Eungwanichayapant, P D; Popluechai, S

    2009-02-01

    Catechins are a group of polyphenols found in tea (Camellia sinensis var. sinensis) at high levels. They are beneficial for health. From the study on accumulation of catechins in shoots and mature leaves of a tea cultivar, Oolong No. 17, using high-performance liquid chromatography (HPLC), it was found that the amounts of most catechins in the shoots were higher than those in the mature leaves, with an exception of catechins gallate (CG) that was found in trace amounts in both the shoots and mature leaves. mRNA accumulation of genes involved in catechin synthesis was studied using reverse transcriptase-polymerase chain reaction (RT-PCR). The results showed that the mRNA accumulation of the genes were higher in the shoots than in the mature leaves. These genes included genes of phenylalanine ammonia-lyase 1 (PAL1; EC 4.3.1.5), chalcone synthase (CHS; EC 2.3.1.74), dihydroflavonol 4-reductase (DFR; EC 1.1.1.219), leucoanthocyanidin reductase (LCR; EC 1.17.1.3), and flavanone 3-hydroxylase (F3H; EC 1.14.11.9).

  1. Phosphate modulated luminescence in lanthanum vanadate nanorods- Catechin, polyphenolic ligand

    Science.gov (United States)

    Tamilmani, Vairapperumal; Nair, Balachandran Unni; Sreeram, Kalarical Janardhanan

    2017-08-01

    Rare earth orthovanadates and phosphates offer a very high opportunity for fabrication of nanoscale devices that exploit their luminescence properties. Optimization of luminescence by way of modulation of size, shape, structure, and morphology has been an area of study for several researchers. There has been a debate as to whether doped orthophosphate or orthovanadate is better luminescent material as both are chemically similar. It has been reported earlier that catechin hydrate can play the role of a structure director and thus influence the luminescence properties of orthovanadates. In this work, a catechin modulated the synthesis of Eu-doped lanthanum orthophosphate by phosphate substitution into vanadate host lattice is reported. A mechanistic understanding of the luminescence changes in LaMO4 has been proposed. During the substitution of V with P, catechin modulates the structure between 1D nanorods and nanowires. The host crystal structure, shape, and size influence the luminescence properties in doped LaMO4.

  2. Determination of catechins and flavonol glycosides in Chinese tea varieties.

    Science.gov (United States)

    Wu, Chunyan; Xu, Hairong; Héritier, Julien; Andlauer, Wilfried

    2012-05-01

    A standardised profiling method based on high performance liquid chromatography combined with ultraviolet (UV) and mass spectrometric detection (MS) was established to analyse the phenolic compounds of selected tea varieties used for manufacturing of green, black and oolong teas. The composition and content of 24 tea constituents were analysed, including catechins, flavonol and flavones glycosides, phenolic acids and purine alkaloids. Each tea variety had a unique chemical profile. The compositions of catechins were lower in the tea varieties for green tea manufacturing, while the content of myricetin glycosides was the lowest in the tea variety for oolong tea manufacturing. The content of individual phenolic compounds in the selected tea varieties is highly variable. However, the content of total catechins is proposed to be helpful to classify tea according to the future application as non fermented green and fermented oolong or black tea.

  3. Analysis on Interaction between Genotype of Four Main Flavonoids of Barley Grain and Environment

    Institute of Scientific and Technical Information of China (English)

    Tao YANG; Chengli DUAN; Yawen ZENG; Juan DU; Shuming YANG; Xiaoying PU; Shengchao YANG

    2012-01-01

    [Objective] This study aimed to analyze the interaction between genotype of flavonoids of barley grain and environment, to increase the flavonoid content of barley grain in cultivation and breeding. [Method] In this study, the content of cate- chin, myricetin, quercetin and kaempferol of barley grain planted in Kunming, Qujing and Baoshan were determined by HPLC, and the genotype, environment, genotype- environment interaction of the flavonoid content of barley grain were analyzed. [Result] According to the experimental results, the genotype variance, environmental variance and G x E interaction variance of catechin and kaempferol contents show the same trend: genotype variation 〉 environmental variation 〉 G × E interaction variation, which all reach a extremely significant level; the genotype variance, envi- ronmental variance and G × E interaction variance of quercetin and total flavonoid contents show the same trend: genetype variation 〉 G × E interaction variation 〉 environmental variation, which all reach a extremely significant level; the genotype variance and environmental variance of myricetin content both reach a extremely sig- nificant level, while the G × E interaction variance reaches a significant level, showing an order of genotype variation 〉 environmental variation 〉 G × E interaction variation; the genotype variance, environmental variance and G x E interaction vari- ance of total flavonoid content show an order of genotype variation 〉 environmental variation 〉 G × E interaction variation. Among different barley varieties, Ziguang- mangluoerling and Kuanyingdamai in Qujing, Kunming and Baoshan have relatively high content of quercetin, while other barley varieties barely contain any quercetin. The grains of Ziguangmangluoerling and Kuanyingdamai are purple, while the grains of other barley varieties are yellow. [Conclusion] Four main flavonoids and the total flavonoids of barley grain are mainly under genetic control and

  4. Antimicrobial activity screening of isolated flavonoids from Azadirachta indica leaves

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    QUDSIA KANWAL

    2011-03-01

    Full Text Available The antimicrobial activities of two flavonoids, namely genistein 7-O-glucoside (1 and (–-epi-catechin (2, isolated from Azadirachta indica A. Juss (neem leaves, were evaluated against five fungal species, viz: Alternaria alternata (Fr. Keissler, Aspergillus fumigatus Fresenius, Aspergillus niger van Tieghem, Macrophomina phaseolina (Tassi Goid. and Penicillium citrii, and four bacterial species, viz. Lactobacillus sp., Escherichia coli, Azospirillium lipoferum and Bacillus sp. Six concentrations, viz. 100, 300, 500, 700, 900 and 1000 ppm of each of the two flavonoids were employed using malt extract agar medium. All the concentrations of both the test compounds significantly suppressed fungal as well as bacterial growth. The highest concentration (1000 ppm of both fractions 1 and 2 reduced the growth of the different test fungal species by 83–99 % and 82–95 %, respectively. Compound 1 was highly effective against Lactobacillus sp., against which its various concentrations reduced the bacterial growth by 52–99.8 %. Compound 2 was highly effective against A. lipoferum and Bacillus sp., resulting in 94–100 % and 73–99% reduction in bacterial growth, respectively.

  5. A RP-HPLC method for the determination of tea catechins

    NARCIS (Netherlands)

    Khokhar, S.; Venema, D.; Hollman, P.C.H.; Dekker, M.; Jongen, W.M.F.

    1997-01-01

    An HPLC method with gradient elution for the quantification of catechins ((−)-epigallocatechin (EGC), ( )-catechin (C), (−)-epicatechin (EC), (−)-epigallocatechingallate (EGCg) and (−)-epicatechingallate (ECg)) in tea was developed. The method was used to determine catechins in black tea, green tea

  6. A RP-HPLC method for the determination of tea catechins

    NARCIS (Netherlands)

    Khokhar, S.; Venema, D.; Hollman, P.C.H.; Dekker, M.; Jongen, W.M.F.

    1997-01-01

    An HPLC method with gradient elution for the quantification of catechins ((−)-epigallocatechin (EGC), ( )-catechin (C), (−)-epicatechin (EC), (−)-epigallocatechingallate (EGCg) and (−)-epicatechingallate (ECg)) in tea was developed. The method was used to determine catechins in black tea, green tea

  7. Biochemical and molecular characterization of a flavonoid 3-O-glycosyltransferase responsible for anthocyanins and flavonols biosynthesis in Freesia hybrida

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    Wei eSun

    2016-03-01

    Full Text Available The glycosylation of flavonoids increases their solubility and stability in plants. Flowers accumulate anthocyanidin and flavonol glycosides which are synthesized by UDP-sugar flavonoid glycosyltransferases (UFGTs. In our previous study, a cDNA clone (Fh3GT1 encoding UFGT was isolated from Freesia hybrida, which was preliminarily proved to be invovled in cyanidin 3-O-glucoside biosynthesis. Here, a variety of anthocyanin and flavonol glycosides were detected in flowers and other tissues of F. hybrida, implying the versatile roles of Fh3GT1 in flavonoids biosynthesis. To further unravel its multi-functional roles, integrative analysis between gene expression and metabolites was investigated. The results showed expression of Fh3GT1 was positively related to the accumulation of anthocyanins and flavonol glycosides, suggesting its potential roles in the biosynthesis of both flavonoid glycosides. Subsequently, biochemical analysis results revealed that a broad range of flavonoid substrates including flavonoid not naturally occurred in F. hybrida could be recognized by the recombinant Fh3GT1. Both UDP-glucose and UDP-galactose could be used as sugar donors by recombinant Fh3GT1, although UDP-galactose was transferred with relatively low activity. Furthermore, regiospecificity analysis demonstrated that Fh3GT1 was able to glycosylate delphinidin at the 3-, 4'- and 7- positions in a sugar-dependent manner. And the introduction of Fh3GT1 into Arabidopsis UGT78D2 mutant successfully restored the anthocyanins and flavonols phenotypes caused by lost-of-function of the 3GT, indicating that Fh3GT1 functions as a flavonoid 3-O-glucosyltransferase in vivo. In summary, these results demonstrate that Fh3GT1 is a flavonoid 3-O-glycosyltransferase using UDP-glucose as the preferred sugar donor and may involve in flavonoid glycosylation in F. hybrida.

  8. Flavonoids from Macaranga lowii

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    Widiastuti Agustina

    2012-03-01

    Full Text Available new isoprenylated dihydroflavonol derivative, macalowiinin (1, together with two known flavonoids 4’-O-methyl-8-isoprenylnaringenin (2 and 4’-O-methyl-5,7,4’-trihydroxyflavone (3 (= acasetin, have been isolated from the methanol extract of the leaves of Macaranga lowii. The structures of these compounds were determined based on UV, NMR, and mass spectral data, and optical rotation. Preliminary cytotoxic evaluation of compounds 1 – 3 against P-388 cells showed that compound 3 is the most active with IC50 was 58.7 mM.

  9. Flavonoids from Symplocos racemosa

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    Mila Jung

    2014-12-01

    Full Text Available A novel isoflavone glycoside, peseudobatigenin 7-O-[β-d-apiofuranosyl-(1''''→5'''-O-β-d-apiofuranosyl-(1'''→6'']-β-d-glucopyranoside, namely sympracemoside (1, was isolated from the aerial parts of Symplocos racemosa along with 15 known flavonoids (2–16. Their structures were characterized by Q-TOF mass, optical rotation, UV, 1D and 2D-NMR spectroscopic data. Compounds 3, 9, 16 showed moderate inhibitory activities against NO production with IC50 value of 88.2, 42.1 and 74.3 μM, respectively.

  10. Flavonoids and Other Phenolic Compounds in Needles of Pinus peuce and Other Pine Species from the Macedonian Flora.

    Science.gov (United States)

    Karapandzova, Marija; Stefkov, Gjose; Cvetkovikj, Ivana; Stanoeva, Jasmina Petreska; Stefova, Marina; Kulevanova, Svetlana

    2015-06-01

    Flavonoids and other phenolic compounds in young needles of four pine species, Pinus peuce, P. nigra, P. mugo and P. sylvestris from the Macedonian flora were investigated. The amount of total phenols and total flavonoids were determined using Folin-Ciocalteau and aluminum chloride assay, respectively. The obtained results revealed that the total phenolic content (TPC) and total flavonoids content (TFC) varied among different pine species ranging from 9.8 to 14.0 mg GAE/g and from 3.3 to 7.2 mg CE/g of dried plant material, respectively. Qualitative analysis of flavonoids and other phenolic components was made by a LC-DAD/ESI-MS(n) optimized chromatographic method. A total of 17 phenolic components were identified and classified as: acids (2), procyanidins (2) and flavonoid glycosides (13). The most prevalent components were flavonoid glycosides, especially flavonols and methylated flavonols (9). Additionally, 3 components were found as acylated flavonol glycosides with ferulic and p-coumaric acid. The last one was found not only in esterified form but also in the free form. Only one flavone-apigenin glycoside was detected. Procyanidins were identified as catechin derivatives, both dimers and trimers.

  11. High performance liquid chromatography tandem mass spectrometry dual extraction method for identification of green tea catechin metabolites excreted in human urine.

    Science.gov (United States)

    Clarke, Kayleigh A; Dew, Tristan P; Watson, Rachel E B; Farrar, Mark D; Bennett, Susan; Nicolaou, Anna; Rhodes, Lesley E; Williamson, Gary

    2014-12-01

    The simultaneous analysis of free-form and conjugated flavonoids in the same sample is difficult but necessary to properly estimate their bioavailability. A method was developed to optimise the extraction of both free and conjugated forms of catechins and metabolites in a biological sample following the consumption of green tea. A double-blind randomised controlled trial was performed in which 26 volunteers consumed daily green tea and vitamin C supplements and 24 consumed a placebo for 3 months. Urine was collected for 24h at 4 separate time points (pre- and post-consumption) to confirm compliance to the supplementation and to distinguish between placebo and supplementation consumption. The urine was assessed for both free and conjugated metabolites of green tea using LC-MS(2) analysis, after a combination extraction method, which involved an ethyl acetate extraction followed by an acetonitrile protein precipitation. The combination method resulted in a good recovery of EC-O-sulphate (91±7%), EGC-O-glucuronide (94±6%), EC (95±6%), EGC (111±5%) and ethyl gallate (74±3%). A potential total of 55 catechin metabolites were investigated, and of these, 26 conjugated (with methyl, glucuronide or sulphate groups) and 3 free-form (unconjugated) compounds were identified in urine following green tea consumption. The majority of EC and EGC conjugates significantly increased post-consumption of green tea in comparison to baseline (pre-supplementation) samples. The conjugated metabolites associated with the highest peak areas were O-methyl-EC-O-sulphate and the valerolactones M6/M6'-O-sulphate. In line with previous studies, EC and EGC were only identified as conjugated derivatives, and EGCG and ECG were not found as mono-conjugated or free-forms. In summary, the method reported here provides a good recovery of catechin compounds and is appropriate for use in the assessment of flavonoid bioavailability, particularly for biological tissues that may contain endogenous

  12. Flavonoids from Lonchocarpus muehlbergianus

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    Magalhães Aderbal F.

    2004-01-01

    Full Text Available The light petroleum extract from the roots of Lonchocarpus muehlbergianus Hassl contained nine flavonoids, including six new ones. These are 2,4-cis-2,4,5,8-tetramethoxy-(2,3:6,7-furanoflavan; 2,4-cis-4-hydroxy-2,5,8-trimethoxy-(2,3:6,7-furanoflavan; 2,4-cis-2-prenyloxy-4,5,8-trimethoxy-(2,3:6,7-fu-ranoflavan; 2,4-cis-2-prenyloxy-4-hydroxy-5,8-dimethoxy-(2,3:6,7-furanoflavan; 2',5',6'-trimethoxy-9-(1,1-dimethylallyoxy-[2,3:3,4]-furanochalcone; 5,6-dimethoxy-(2,3:7,8-furanoflavone, identi-fied by analysis of their spectral data (UV, IR, ¹H and 13C NMR, 2D-NMR, NOE and MS. The natural occurrence of 2,4-dioxygenated flavan derivatives is being reported for the first time. Quantitative analysis of the petrol extract, by using reversed-phase HPLC, showed that the most abundant flavonoid in the extract is 2,4-cis-2,4,5,8- tetramethoxy-(2,3:6,7-furanoflavan.

  13. New biflavonoid and other flavonoids from the leaves of Chimarrhis turbinata and their antioxidant activities

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Carmem L.; Silva, Dulce H.S.; Castro-Gamboa, Ian; Bolzani, Vanderlan da S. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica]. E-mail: bolzaniv@iq.unesp.br

    2005-11-15

    A new biflavonol, named chimarrhoside (1), and eight known flavonol glycosides (2-9), were isolated from the leaves of Chimarrhis turbinata. Their structures were established on the basis of 1D and 2D NMR experiments as quercetin-3-O-rutinoside (2), kaempferol-3-O-rutinoside (3), kaempferol-3-O-{alpha}-L-rhamnopyranosyl-(1{yields}6)-{beta}-D-galactopyranoside (4), quercetin-3-O-{alpha}-L-rhamnopyranosyl-(1{yields}6)- {beta}-D-galactopyranoside (5), 6-hydroxy-rutin (6), kaempferol-3-Oalactopyranoside (7), kaempferol-3-O-D-glucopyranoside (8) and kaempferol-3-O-{alpha}-L-rhamnopyranosyl-(1{yields}6)-{alpha}-L-rhamnopyranosyl-(1= {yields}4)-{beta}-D- glucopyranoside (9). In addition, catechin (10) and catechin-(4{alpha}{yields}8)-catechin-procyanidin B-3) (11) were isolated. The crude extract, fractions and isolated compounds were evaluated for their antioxidative properties using an autographic assay based on {beta}-carotene bleaching on TLC plates, and spectrophotometric detection by reduction of the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. Flavonoids 2, 5, 6, 10 and 11 displayed strong free radical scavenging activity, when compared with the standards BHT and rutin. (author)

  14. Cytoprotection by almond skin extracts or catechins of hepatocyte cytotoxicity induced by hydroperoxide (oxidative stress model) versus glyoxal or methylglyoxal (carbonylation model).

    Science.gov (United States)

    Dong, Qiang; Banaich, Monica S; O'Brien, Peter J

    2010-04-29

    Oxidative and carbonyl stress are detrimental in the pathogenesis of diabetic complications, as well as in other chronic diseases. However, this process may be decreased by dietary bioactive compounds. Almond skin is an abundant source of bioactive compounds and antioxidants, including polyphenolic flavonoids, which may contribute to the decrease in oxidative and carbonyl stress. In this study, four Almond Skin Extracts (ASEI, ASEII, ASEIII, and ASEIV) were prepared by different methods and evaluated for their antioxidant activity. The order of the polyphenol content (total muM gallic acid equivalents) of the four extracts was found to be, in decreasing order of effectiveness: ASEI>ASEIII>ASEIV>ASEII. The order of Ferric-reducing antioxidant power (FRAP, microM FeSO(4)/g) value, in decreasing order was ASEI (216)>ASEIII (176)>ASEIV (89)>ASEII (85). The order of ASE effectiveness for decreasing protein carbonyation induced by the copper Fenton reaction was ASEI>ASEIV>ASEII>ASEIII. The order of antioxidant effectiveness for inhibiting tertiary-butyl hydroperoxide (TBH) induced microsomal lipid peroxidation was ASEI>ASEIV>ASEII, ASEIII. Also, the order of ASE effectiveness for inhibiting TBH induced hepatocyte cell death was: ASEIII, ASEIV>ASEI, ASEII. Catechin also protected hepatocytes from TBH induced hepatocyte, lipid peroxidation and cytotoxicity. In a cell free model, equimolar concentrations of catechin or epicatechin rescued serum albumin from protein carbonylation induced by methylglyoxal (MGO). Catechin, epicatechin and ASEI all decreased gloxal induced hepatocyte cell death and reactive oxygen species (ROS) formation in GSH-depleted hepatocytes. Catechin and epicatechin protected against GO or MGO induced hepatocyte cell death, protein carbonylation and ROS formation. Catechin was more effective than epicatechin. Our results suggest that (a) bioactive almond skin constituents in the non-lipophilic polyphenol extract were the most effective at protecting

  15. Effects of Drying Temperature on Flavonoids Extraction Rate from Young Stems and Leaves of Two Cassava Varieties

    Directory of Open Access Journals (Sweden)

    WANG Ding-mei

    2017-01-01

    Full Text Available To improve flavonoids resources utilization level of young cassava stems and leaves, using cassava varieties SC09 and SC205 as ob jects, investigated the effect of different drying temperatures(40~120℃on the flavonoids extraction rate(FERand their stability in 120 d storage period after drying, explored a right drying storage method for postharvest young cassava stems and leaves. The research showed that total FER rised first, and then fell and rised again with the increase of drying temperature. During 40~80℃, the total FER was obviously in fluenced by variety and temperature, but only temperature was main factor affecting total FER during 90~120℃. Extract degree of flavonoids include rutin, amentoflavone or catechin, kaempferol, hesperidin, quercetin minished in order; the effect of cassava variety on the extraction rate of catechin and hesperidin was greater than that of drying temperature, but that contrary to other 4 flavonoids. Variety and temperature had a maximum impact respectively on catechin and rutin extraction rates. Whereas both of variety and temperature had a minimum impact on kaempferol extraction rate. FER reached higher levels of 1.42%and 1.53% respectively in SC09 after 120℃drying and SC205 after 110℃drying, and had best stability during 120 d storage period. The extraction rate of hesperidin increased after drying storage, and that of other 5 ingredients were changing with different varieties and temperatures; the coefficient variation(CV=1.03%~6.86%of kaempferol was minimum and its stability was best; extraction rates of rutin and kaempferol in SC205 after 110℃drying were maximum, whose increasing rates were 44.89%and 7.27%respectively with a small separate degree(CV were 6.94%, 4.59%and good extraction stability. Maximum in creasing rates of catechin, amentoflavone, quercetin and hesperidin were 211.60%,17.60%,186.39% and 538.08% respectively. However,their stabilities of extraction efficiency were poor

  16. Cloning and Characterization of a Flavonoid 3′-Hydroxylase Gene from Tea Plant (Camellia sinensis

    Directory of Open Access Journals (Sweden)

    Tian-Shan Zhou

    2016-02-01

    Full Text Available Tea leaves contain abundant flavan-3-ols, which include dihydroxylated and trihydroxylated catechins. Flavonoid 3′-hydroxylase (F3′H: EC 1.14.13.21 is one of the enzymes in the establishment of the hydroxylation pattern. A gene encoding F3′H, designated as CsF3′H, was isolated from Camellia sinensis with a homology-based cloning technique and deposited in the GenBank (GenBank ID: KT180309. Bioinformatic analysis revealed that CsF3′H was highly homologous with the characterized F3′Hs from other plant species. Four conserved cytochrome P450-featured motifs and three F3′H-specific conserved motifs were discovered in the protein sequence of CsF3′H. Enzymatic analysis of the heterologously expressed CsF3′H in yeast demonstrated that tea F3′H catalyzed the 3′-hydroxylation of naringenin, dihydrokaempferol and kaempferol. Apparent Km values for these substrates were 17.08, 143.64 and 68.06 μM, and their apparent Vmax values were 0.98, 0.19 and 0.44 pM·min−1, respectively. Transcription level of CsF3′H in the new shoots, during tea seed germination was measured, along with that of other key genes for flavonoid biosynthesis using real-time PCR technique. The changes in 3′,4′-flavan-3-ols, 3′,4′,5′-flavan-3-ols and flavan-3-ols, were consistent with the expression level of CsF3′H and other related genes in the leaves. In the study of nitrogen supply for the tea plant growth, our results showed the expression level of CsF3′H and all other tested genes increased in response to nitrogen depletion after 12 days of treatment, in agreement with a corresponding increase in 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols content in the leaves. All these results suggest the importance of CsF3′H in the biosynthesis of 3′,4′-catechins, 3′,4′,5′-catechins and flavan 3-ols in tea leaves.

  17. Home blood sugar testing

    Science.gov (United States)

    Diabetes - home glucose testing; Diabetes - home blood sugar testing ... Usual times to test your blood sugar are before meals and at bedtime. Your provider may ask you to check your blood sugar 2 hours after a meal or ...

  18. Sweeteners - sugar substitutes

    Science.gov (United States)

    Artificial sweeteners are substances that are used in place of sweeteners with sugar (sucrose) or sugar alcohols . They ... foods and drinks without adding extra calories. Using artificial sweeteners in place of sugar can also help prevent ...

  19. Spectroscopic analysis of catechins in peanut seed skins

    Science.gov (United States)

    Peanuts, Arachis hypogaea, are cultivated as a source of edible seed oil and protein. The peanut seed testa or skin that surrounds the seed is typically removed after the shelling process by blanching. Several phenolic compounds such as catechins may be isolated as co-products from peanut seed skins...

  20. Do pH and flavonoids influence hypochlorous acid-induced catalase inhibition and heme modification?

    Science.gov (United States)

    Krych-Madej, Justyna; Gebicka, Lidia

    2015-09-01

    Hypochlorous acid (HOCl), highly reactive oxidizing and chlorinating species, is formed in the immune response to invading pathogens by the reaction of hydrogen peroxide with chloride catalyzed by the enzyme myeloperoxidase. Catalase, an important antioxidant enzyme, catalyzing decomposition of hydrogen peroxide to water and molecular oxygen, hampers in vitro HOCl formation, but is also one of the main targets for HOCl. In this work we have investigated HOCl-induced catalase inhibition at different pH, and the influence of flavonoids (catechin, epigallocatechin gallate and quercetin) on this process. It has been shown that HOCl-induced catalase inhibition is independent on pH in the range 6.0-7.4. Preincubation of catalase with epigallocatechin gallate and quercetin before HOCl treatment enhances the degree of catalase inhibition, whereas catechin does not affect this process. Our rapid kinetic measurements of absorption changes around the heme group have revealed that heme modification by HOCl is mainly due to secondary, intramolecular processes. The presence of flavonoids, which reduce active catalase intermediate, Compound I to inactive Compound II have not influenced the kinetics of HOCl-induced heme modification. Possible mechanisms of the reaction of hypochlorous acid with catalase are proposed and the biological consequences are discussed.

  1. Effects of (+-Catechin on the Composition, Phenolic Content and Antioxidant Activity of Full-Fat Cheese during Ripening and Recovery of (+-Catechin after Simulated In Vitro Digestion

    Directory of Open Access Journals (Sweden)

    Ali Rashidinejad

    2016-08-01

    Full Text Available (+-Catechin, the representative catechin in green tea, was incorporated into a full-fat cheese (at 125–500 ppm followed by ripening for 90 days at 8 °C and digesting for six hours. Determination of pH, proximate composition, total phenolic content (TPC and antioxidant activity (AA after manufacture and ripening demonstrated that the addition of (+-catechin significantly (p ≤ 0.05 decreased the pH of both whey and curd during cheese manufacturing and ripening with no significant (p > 0.05 effect on the moisture, protein and fat contents. (+-Catechin increased TPC, as well as AA, though the increase was not proportional with increasing the concentration of added (+-catechin. About 57%–69% of (+-catechin was retained in the cheese curd, whereas about 19%–39% (depending on the concentration was recovered from the cheese digesta. Transmission electron micrographs showed that the ripened control cheese had a homogeneous pattern of milk fat globules with regular spacing entrapped in a homogenous structure of casein proteins, whereas the addition of (+-catechin disrupted this homogenous structure. The apparent interaction between (+-catechin and cheese fat globules was confirmed by Fourier transform infrared spectroscopy. These associations should be taken into account when incorporating antioxidants, such as (+-catechin, to create functional dairy products, such as cheese.

  2. Effects of (+)-Catechin on the Composition, Phenolic Content and Antioxidant Activity of Full-Fat Cheese during Ripening and Recovery of (+)-Catechin after Simulated In Vitro Digestion.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-08-27

    (+)-Catechin, the representative catechin in green tea, was incorporated into a full-fat cheese (at 125-500 ppm) followed by ripening for 90 days at 8 °C and digesting for six hours. Determination of pH, proximate composition, total phenolic content (TPC) and antioxidant activity (AA) after manufacture and ripening demonstrated that the addition of (+)-catechin significantly (p ≤ 0.05) decreased the pH of both whey and curd during cheese manufacturing and ripening with no significant (p > 0.05) effect on the moisture, protein and fat contents. (+)-Catechin increased TPC, as well as AA, though the increase was not proportional with increasing the concentration of added (+)-catechin. About 57%-69% of (+)-catechin was retained in the cheese curd, whereas about 19%-39% (depending on the concentration) was recovered from the cheese digesta. Transmission electron micrographs showed that the ripened control cheese had a homogeneous pattern of milk fat globules with regular spacing entrapped in a homogenous structure of casein proteins, whereas the addition of (+)-catechin disrupted this homogenous structure. The apparent interaction between (+)-catechin and cheese fat globules was confirmed by Fourier transform infrared spectroscopy. These associations should be taken into account when incorporating antioxidants, such as (+)-catechin, to create functional dairy products, such as cheese.

  3. Sugar Substitutes: Artificial Sweeteners and Sugar Alcohols

    OpenAIRE

    Washburn, Carolyn; Christensen, Nedra

    2012-01-01

    Most people enjoy the sweet taste of food. Artificial sweeteners and sugar alcohols can provide the sweet flavor and be beneficial for people with diabetes or those choosing to avoid sugars because they contain lower calories and carbohydrates than regular sugars. These products are also beneficial in that they do not cause tooth decay.

  4. Chocolate as a source of tea flavonoids

    NARCIS (Netherlands)

    Arts, I.C.W.; Hollman, P.C.H.; Kromhout, D.

    1999-01-01

    The antioxidant catechin content of chocolate is four times that of tea. Chocolate contributed 20% of the catechin intake in a representative sample of the Dutch population, and tea contributes 55%. Epidemiological assessments of health effects of tea should include other foods that are sources of

  5. Chocolate as a source of tea flavonoids

    NARCIS (Netherlands)

    Arts, I.C.W.; Hollman, P.C.H.; Kromhout, D.

    1999-01-01

    The antioxidant catechin content of chocolate is four times that of tea. Chocolate contributed 20% of the catechin intake in a representative sample of the Dutch population, and tea contributes 55%. Epidemiological assessments of health effects of tea should include other foods that are sources of c

  6. Chemiluminescence assay for catechin based on generation of hydrogen peroxide in basic solution

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Hidetoshi; Kanemitsu, Mahina; Tajima, Noriko; Maeda, Masako

    2002-11-20

    We have determined that the catechin group in basic solution efficiently produces hydrogen peroxide; moreover, a highly sensitive analysis methodology was developed to measure catechin employing a peroxalate chemiluminescence detection system. Identification of hydrogen peroxide generated by catechin was determined by ESR as well as peroxalate chemiluminescence using catalase and SOD. As a result, catechin-generated superoxide by electron reduction to dissolved oxygen in basic solution, followed by production of hydrogen peroxide through dismutation reaction. This method could measure several tea catechins, (+)-catechin (CC), (-)-epigallocatechin-3-gallate (EGCg), (-)-epicatechin-3-gallate (ECG) and gallic acid, with measurement range from 10{sup -7} to 10{sup -3} mol/l and sensitivity of 10{sup -8} mol/l. This method was also applied to the determination of total catechin levels in green tea, black tea and roasted green tea.

  7. Differential expression of flavonoid biosynthesis genes and accumulation of phenolic compounds in common buckwheat (Fagopyrum esculentum).

    Science.gov (United States)

    Li, Xiaohua; Park, Nam Il; Xu, Hui; Woo, Sun-Hee; Park, Cheol Ho; Park, Sang Un

    2010-12-01

    Common buckwheat (Fagopyrum esculentum) is a short-season grain crop that is a source of rutin and other phenolic compounds. In this study, we isolated the cDNAs of 11 F. esculentum enzymes in the flavonoid biosynthesis pathway, namely, phenylalanine ammonia lyase (PAL), cinnamate 4-hydroxylase (C4H), 4-coumarate:CoA ligase (4CL) 1 and 2, chalcone synthase (CHS), chalcone isomerase (CHI), flavone 3-hydroxylase (F3H), flavonoid 3'-hydroxylase (F3'H), flavonol synthase (FLS) 1 and 2, and anthocyanidin synthase (ANS). Quantitative real-time polymerase chain reaction analysis showed that these genes were most highly expressed in the stems and roots. However, high performance liquid chromatography analysis indicated that their flavonoid products, such as rutin and catechin, accumulated in the flowers and leaves. These results suggested that flavonoids may be transported within F. esculentum. In addition, light and dark growth conditions affected the expression levels of the biosynthesis genes and accumulation of phenolic compounds in F. esculentum sprouts.

  8. Dietary flavonoid intake, black tea consumption, and risk of overall and advanced stage prostate cancer.

    Science.gov (United States)

    Geybels, Milan S; Verhage, Bas A J; Arts, Ilja C W; van Schooten, Frederik J; Goldbohm, R Alexandra; van den Brandt, Piet A

    2013-06-15

    Flavonoids are natural antioxidants found in various foods, and a major source is black tea. Some experimental evidence indicates that flavonoids could prevent prostate cancer. We investigated the associations between flavonoid intake, black tea consumption, and prostate cancer risk in the Netherlands Cohort study, which includes 58,279 men who provided detailed baseline information on several cancer risk factors. From 1986 to 2003, 3,362 prostate cancers were identified, including 1,164 advanced (stage III/IV) cancers. Cox proportional hazards regression using the case-cohort approach was used to estimate hazard ratios and 95% confidence intervals. Intake of total catechin, epicatechin, kaempferol, and myricetin and consumption of black tea were associated with a decreased risk of stage III/IV or stage IV prostate cancer. Hazard ratios of stage III/IV and stage IV prostate cancer for the highest versus the lowest category of black tea consumption (≥5 versus ≤1 cups/day) were 0.75 (95% confidence interval: 0.59, 0.97) and 0.67 (95% confidence interval: 0.50, 0.91), respectively. No associations were observed for overall and nonadvanced prostate cancer. In conclusion, dietary flavonoid intake and black tea consumption were associated with a decreased risk of advanced stage prostate cancer.

  9. Huanglongbing modifies quality components and flavonoid content of 'Valencia' oranges.

    Science.gov (United States)

    Massenti, Roberto; Lo Bianco, Riccardo; Sandhu, Amandeep K; Gu, Liwei; Sims, Charles

    2016-01-15

    In order to evaluate the effect of citrus greening disease, or Huanglongbing (HLB), on quality components and flavonoid contents of 'Valencia' oranges, fruit from non-infected trees (control), from infected trees but symptom-less (asymptomatic) and from infected trees and showing clear HLB symptoms (symptomatic) were harvested in March and in May, 2013. Fruit peel, pulp and juice were separated, the main quality components were determined, and hesperidin, nobiletin, tangeretin, narirutin and didymin were quantified using liquid chromatography. Peel colour, total soluble solids and citric acid were similar in control and asymptomatic fruits. Symptomatic fruits were smaller, yielded less juice, had higher acidity and lower sugar and peel colour than control fruits. In the peel, hesperidin, nobiletin, tangeretin, narirutin and didymin were higher in symptomatic than in asymptomatic and control fruits. Peel flavonoids decreased with fruit maturation. Also, in pulp and juice, flavonoid content was higher in symptomatic than in asymptomatic and control fruits. These results show that asymptomatic fruits are similar to control fruits more than to symptomatic fruits, suggesting that secondary metabolism and physical properties of fruits are only affected at a later and more advanced stage of HLB infection. Despite the significant loss of quality, fruit with clear HLB symptoms accumulate high quantities of flavonoids in peel and pulp. © 2014 Society of Chemical Industry.

  10. Flavonoids from Pseudotsuga menziesii.

    Science.gov (United States)

    Krauze-Baranowska, Mirosława; Sowiński, Paweł; Kawiak, Anna; Sparzak, Barbara

    2013-01-01

    Four O-acylated flavonol glycosides, new in the plant kingdom, were isolated from the needles of Pseudotsuga menziesii. Their structures were established by 1D and 2D NMR and MS data as: daglesioside I [kaempferol 3-O-[2",5"-O-(4''',4(IV)-dihydroxy)-beta-truxinoyl]-alpha-L-arabinofuranoside] (1), daglesioside II [kaempferol 3-O-[2",5"-O-(4"'-hydroxy)-beta-truxinoyl]-alpha-L-arabinofuranoside] (2), daglesioside III [kaempferol 3-O-[2",5"-di-O-(E)-p-coumaroyl]-alpha-L-arabinofuranoside] (3), and daglesioside IV [kaempferol 3-O-[3",6"-di-O-(E)-cinnamoyl]-beta-D-glucopyranoside] (4). In addition, the known flavonoids (E)-tiliroside, (E)-ditiliroside, astragalin (kaempferol 3-O-beta-D-glucopyranoside), isorhamnetin, kaempferol, and quercetin were identified. The cytotoxic activity of compounds 1 and 3 was evaluated towards the HL-60, HeLa, and MDA-MB468 cell lines.

  11. Biochemical changes in phenols, flavonoids, tannins, vitamin E,β-carotene and antioxidant activity during soaking of three whitesorghum varieties

    Institute of Scientific and Technical Information of China (English)

    Abd El-Moneim MR Afify; Hossam S El-Beltagi; Samiha M Abd El-Salam; Azza A Omran

    2012-01-01

    Objective: To investigate the changes in total phenols, flavonoids, tannins, vitamin E,β-carotene and antioxidant activity during soaking of three white sorghum varieties. Methods:The changes in total phenols, total flavonoids, tannins, phenolic acids compounds, flavonoid components, vitamin E, β-carotene and antioxidant activity during soaking of sorghum grains were determined. Results: Total phenols, total flavonoids, tannins, vitamin E, β-carotene and antioxidant activity in raw sorghum were ranged from 109.21 to 116.70, 45.91 to 54.69, 1.39 to 21.79 mg/100 g, 1.74 to 5.25, 0.54 to 1.19 mg/kg and 21.72% to 27.69% and 25.29% to 31.97%, respectively. The above measured compounds were significantly decreased after soaking. p-Hydroxybenzoic acid, vanillic acid, syringic acid and cinnamic acid represent the major phenolic acids in Dorado variety. While ferulic acid, p-coumaric acid, gallic acid and caffeic acid represent the major phenolic acids in Shandaweel-6. On the other hand, protocatechuic acid represents the major phenolic acids in Giza-15. Regarding flavonoids components, Dorado was the highest variety in kampferol and naringenin while Shandaweel-6 was the highest variety in luteolin, apigenin, hypersoid, quercetin and christen. Finally, Giza-15 was the highest variety in catechin. Phenolic acids, flavonoid compounds and antioxidant activities were decreased after soaking.Conclusions:tannins, phenolic acids compounds, flavonoid components, vitamin E, β-carotene and antioxidant activity which decreased after soaking. Sorghum varieties have moderate quantities from total phenols, total flavonoids

  12. The Occurrence, Fate and Biological Activities of C-glycosyl Flavonoids in the Human Diet.

    Science.gov (United States)

    Courts, Fraser L; Williamson, Gary

    2015-01-01

    The human diet contains a wide variety of plant-derived flavonoids, many of which are glycosylated via an O- or less commonly a C-glycosidic linkage. The distribution, quantity, and biological effects of C-glycosyl flavonoids in the human diet have received little attention in the literature in comparison to their O-linked counterparts, however, despite being present in many common foodstuffs. The structural nature, nomenclature, and distribution of C-glycosyl flavonoids in the human diet are, therefore, reviewed. Forty-three dietary flavonoids are revealed to be C-glycosylated, arising from the dihydrochalcone, flavone, and flavan-3-ol backbones, and distributed among edible fruits, cereals, leaves, and stems. C-linked sugar groups are shown to include arabinose, galactose, glucose, rutinose, and xylose, often being present more than once on a single flavonoid backbone and occasionally in tandem with O-linked glucose or rutinose groups. The pharmacokinetic fate of these compounds is discussed with particular reference to their apparent lack of interaction with hydrolytic mechanisms known to influence the fate of O-glycosylated dietary flavonoids, explaining the unusual but potentially important appearance of intact C-glycosylated flavonoid metabolites in human urine following oral administration. Finally, the potential biological significance of these compounds is reviewed, describing mechanisms of antidiabetic, antiinflammatory, anxiolytic, antispasmodic, and hepatoprotective effects.

  13. Tea catechins with a galloyl moiety suppress postprandial hypertriacylglycerolemia by delaying lymphatic transport of dietary fat in rats.

    Science.gov (United States)

    Ikeda, Ikuo; Tsuda, Koichi; Suzuki, Yuko; Kobayashi, Makoto; Unno, Tomonori; Tomoyori, Hiroko; Goto, Hitomi; Kawata, Yayoi; Imaizumi, Katsumi; Nozawa, Ayumu; Kakuda, Takami

    2005-02-01

    Tea catechins, (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), have been shown to be epimerized to (-)-catechin (C), (-)-gallocatechin (GC), (-)-catechin gallate (CG), and (-)-gallocatechin gallate (GCG), respectively, during heat treatment. In this study, we examined the effect of tea catechins rich in ECG and EGCG and heat-treated tea catechins rich in CG and GCG on postprandial hypertriacylglycerolemia in rats. Both tea catechins and heat-treated tea catechins suppressed postprandial hypertriacylglycerolemia. Lymphatic recovery of (14)C-trioleoylglycerol in rats cannulated in the thoracic duct was delayed by the administration of tea catechins and heat-treated tea catechins. Tea catechins and heat-treated tea catechins had the same effect on all variables tested. These catechin preparations dose-dependently inhibited the activity of pancreatic lipase in vitro. When purified catechins were used, only those with a galloyl moiety inhibited the activity of pancreatic lipase. These results suggest that catechins with a galloyl moiety suppress postprandial hypertriacylglycerolemia by slowing down triacylglycerol absorption through the inhibition of pancreatic lipase. Because postprandial hypertriacylglycerolemia is a risk factor for coronary heart disease, our results suggest that catechins with a galloyl moiety may prevent this disease.

  14. Flavonoid intake and eye health.

    Science.gov (United States)

    Milbury, Paul E

    2012-01-01

    In the modern era of evidence-based scientific medicine, there is little recognition of centuries of shaman observational evidence. Yet it is extremely difficult to conduct long duration controlled studies of large populations. The controversy surrounding the issue of flavonoid bioactivity and alleged benefits for eye health is also plagued by natural product industry marketing efforts that rely on small, often poorly designed studies. Ample laboratory evidence exists from in vitro and in vivo studies that provide plausible mechanistic evidence for flavonoid interactions relevant to visual function. Lacking are large randomized double-blind placebo-controlled studies in older subjects who have early signs of vision impairment. These studies could link flavonoid intake and bioavailability to efficacy in prevention of age related vision disorders that develop over decades. Support for clinical trials remains to be found before a full "recommendation" can be made regarding the value of diets high in flavonoids for eye health.

  15. Flavonoids, Inflammation and Immune System

    Directory of Open Access Journals (Sweden)

    Francisco J. Pérez-Cano

    2016-10-01

    Full Text Available Flavonoids, including around 6000 phenolic compounds, are products of the secondary metabolism of plants which can be a part of one’s diet via the consumption of many edible plants.[...

  16. Excretion of Four Catechins in Tea Polyphenols in Rats

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To investigate excretion profiles of the four major anti-oxidant active catechins, (-) epigallo-catechin-3-gallate (EGCG), (-) epicatechin-3-gallate (ECG), (-) epigallocatechin (EGC), and epicatechin (EC) in tea polyphenols (TP) in rats in order to provide experimental data for clinical uses and development of TP as a novel drug. Methods The above four catechins in urine, bile, and feces were simultaneously determined by high performance liquid chromatography coupled with ultraviolet absorption detector (HPLC-UV) assay with a binary gradient elution. The samples were extracted by ethyl acetate prior to HPLC. The quantification was carried out by peak area internal standard method. Following iv dosing TP 100 mg/kg to rats, the samples were collected at different time intervals up to 8 h (urine and bile) and 24 h (feces). Results The urinary Ae, 0-8 h (cumulative excretion amount over 8 h) of EGCG, ECG, EGC, and EC were, on the average, 150.83, 30.75, 116.69, and 254.56 μg, corresponding to fe, 0-8 h (cumulative excretion fraction of dose over 8 h) of 1.45%, 0.84%, 7.88%, and 10.73%, respectively; the biliary Ae, 0-8 h were 12.61, 42.64, 6.61, and 1.24 μg, corresponding to the fe, 0-8 h of 0.12%, 1.16%, 0.45%, and 0.053%,respectively. For fecal excretion, only EGCG and EGC were detected with Ae, 0-24 h of 7.38 μg (fe, 0-24 h of 0.07%) and 157 μg (fe, 0-24 h of 9.99 %), respectively. The fe, total (the total fe of 3 excretory routes) were 18.32%, 10.78%, 2.00%, and 1.64% for EGC, EC, ECG, and EGCG, respectively. Conclusion EGCG and EC are mainly excreted in urine, ECG in bile, and EGC in feces by reference to their Ae and fe. The excretion of the four catechins based on fe, total is ranked in order of EGC > EC > ECG > EGCG. Only small amount of four catechins are recovered in urine, bile, and feces, indicating an extensive metabolic conversion of catechins in the rat body.

  17. Association of Catechin Molecules in Water: Quantitative Binding Study and Complex Structure Analysis.

    Science.gov (United States)

    Ujihara, Tomomi; Hayashi, Nobuyuki

    2016-01-22

    Associations between catechin molecules were investigated by (1)H NMR titration experiments. Eight green tea catechins formed self-assembled dimers in water, and gallate-type catechins had a greater tendency to self-associate than non-gallate-type catechins. All eight catechins also associated as 1:1 heterodimer complexes. Investigation of complex formation of epigallocatechin-3-O-gallate (EGCg) and epigallocatechin (EGC) with the other catechins showed that the affinity between EGCg and 2,3-trans-gallate-type catechins was remarkably high, and the binding affinity of EGCg for ECg was also rather strong. In contrast, the non-gallate-type catechin EGC exhibited generally low binding affinity for other catechins. Structural analyses of the complexes by ROESY experiments and density functional theory calculations demonstrated that the higher binding abilities of gallate-type catechins are due to providing multiple intermolecular interactions that remain effective in an aqueous environment, such as aromatic/aromatic or CH/π interactions.

  18. Subcellular Localization of Galloylated Catechins in Tea Plants (Camellia sinensis (L. O. Kuntze Assessed via Immunohistochemistry

    Directory of Open Access Journals (Sweden)

    Huanhuan eXu

    2016-05-01

    Full Text Available Galloylated catechins, as the main secondary metabolites in the tea plant, including (--epigallocatechin-3-gallate and (--epicatechin-3-gallate, comprise approximately three-quarters of all the tea plant catechins and have stronger effects than non-galloylated catechins, both on the product quality in tea processing and the pharmacological efficacy to human beings. The subcellular localization of galloylated catechins has been the primary focus of studies that assess biosynthesis and physiological functions. Classical histochemical localization staining reagents can not specifically detect galloylated catechins; thus, their subcellular localization remains controversial. In the present study, we generated a monoclonal antibody (mAb against galloylated catechins, which can be used for the subcellular localization of galloylated catechins in the tea plant by immunohistochemistry. Direct ELISA and ForteBio Octet Red 96 System assay indicated the mAb could recognize the galloylated catechins with high specificities and affinities. In addition, tea bud was ascertained as the optimal tissue for freezing microtomic sections for immunohistochemistry. What’s more, the high quality mAbs which exhibited excellent binding capability to galloylated catechins were utilised for the visualization of them via immunohistochemistry. Our findings demonstrated that vacuoles were the primary sites of localization of galloylated catechins at the subcellular level.

  19. Antioxidant and protective effect of inulin and catechin grafted inulin against CCl4-induced liver injury.

    Science.gov (United States)

    Liu, Jun; Lu, Jian-feng; Wen, Xiao-yuan; Kan, Juan; Jin, Chang-hai

    2015-01-01

    In this study, the antioxidant activity and hepatoprotective effect of inulin and catechin grafted inulin (catechin-g-inulin) against carbon tetrachloride (CCl4)-induced acute liver injury were investigated. Results showed that both inulin and catechin-g-inulin had moderate scavenging activity on superoxide radical, hydroxyl radical and H2O2, as well as lipid peroxidation inhibition effect. The antioxidant activity decreased in the order of Vc > catechin >catechin-g-inulin > inulin. Administration of inulin and catechin-g-inulin could significantly reduce the elevated levels of serum aspartate transaminase, alanine transaminase and alkaline phosphatase as compared to CCl4 treatment group. Moreover, inulin and catechin-g-inulin significantly increased the levels of hepatic superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione and total antioxidant capacity, whereas markedly decreased the malondialdehyde level when compared with CCl4 treatment group. Notably, catechin-g-inulin showed higher hepatoprotective effect than inulin. In addition, the hepatoprotective effect of catechin-g-inulin was comparable to positive standard of silymarin. Our results suggested that catechin-g-inulin had potent antioxidant activity and potential protective effect against CCl4-induced acute liver injury.

  20. Flavonoids from Teucrium fruticans L.

    Directory of Open Access Journals (Sweden)

    Wanda Kisiel

    2014-01-01

    Full Text Available From aerial parts of Teucrium fncticans L. three flavonoids were isolated and identified as 5-hydroxy-6, 7, 3', 4'-tetramethoxyflavone, 5, 4'-dihydroxy-6, 7, 3'-trimethoxyflavone (cirsilineol and 5, 4'-dihydroxy-6, 7-dimethoxyflavone (cirsimaritin. The former compound was found to be a predominant flavone aglycone constituent of the plant material. This is the first report on the isolation of flavonoids from the plant.

  1. Flavonoid Interaction with a Chitinase from Grape Berry Skin: Protein Identification and Modulation of the Enzymatic Activity.

    Science.gov (United States)

    Filippi, Antonio; Petrussa, Elisa; Rajcevic, Uros; Čurin Šerbec, Vladka; Passamonti, Sabina; Renzone, Giovanni; Scaloni, Andrea; Zancani, Marco; Vianello, Angelo; Braidot, Enrico

    2016-09-28

    In the present study, an antibody raised against a peptide sequence of rat bilitranslocase (anti-peptide Ab) was tested on microsomal proteins obtained from red grape berry skin. Previously, this antibody had demonstrated to recognize plant membrane proteins associated with flavonoid binding and transport. Immuno-proteomic assays identified a number of proteins reacting with this particular antibody, suggesting that the flavonoid binding and interaction may be extended not only to carriers of these molecules, but also to enzymes with very different functions. One of these proteins is a pathogenesis-related (PR) class IV chitinase, whose in vitro chitinolytic activity was modulated by two of the most representative flavonoids of grape, quercetin and catechin, as assessed by both spectrophotometric and fluorimetric assays in grape microsomes and commercial enzyme preparations. The effect of these flavonoids on the catalysis and its kinetic parameters was also evaluated, evidencing that they determine a hormetic dose-dependent response. These results highlight the importance of flavonoids not only as antioxidants or antimicrobial effectors, but also as modulators of plant growth and stress response. Implications of the present suggestion are here discussed in the light of environment and pesticide-reduction concerns.

  2. Flavonoid Interaction with a Chitinase from Grape Berry Skin: Protein Identification and Modulation of the Enzymatic Activity

    Directory of Open Access Journals (Sweden)

    Antonio Filippi

    2016-09-01

    Full Text Available In the present study, an antibody raised against a peptide sequence of rat bilitranslocase (anti-peptide Ab was tested on microsomal proteins obtained from red grape berry skin. Previously, this antibody had demonstrated to recognize plant membrane proteins associated with flavonoid binding and transport. Immuno-proteomic assays identified a number of proteins reacting with this particular antibody, suggesting that the flavonoid binding and interaction may be extended not only to carriers of these molecules, but also to enzymes with very different functions. One of these proteins is a pathogenesis-related (PR class IV chitinase, whose in vitro chitinolytic activity was modulated by two of the most representative flavonoids of grape, quercetin and catechin, as assessed by both spectrophotometric and fluorimetric assays in grape microsomes and commercial enzyme preparations. The effect of these flavonoids on the catalysis and its kinetic parameters was also evaluated, evidencing that they determine a hormetic dose-dependent response. These results highlight the importance of flavonoids not only as antioxidants or antimicrobial effectors, but also as modulators of plant growth and stress response. Implications of the present suggestion are here discussed in the light of environment and pesticide-reduction concerns.

  3. Green tea catechins: inhibitors of glycerol-3-phosphate dehydrogenase.

    Science.gov (United States)

    Kao, Chung-Cheng; Wu, Bo-Tsung; Tsuei, Yi-Wei; Shih, Li-Jane; Kuo, Yu-Liang; Kao, Yung-Hsi

    2010-05-01

    Green tea catechins, especially (-)-epigallocatechin-3-gallate (EGCG), are known to regulate obesity and fat accumulation. We performed a kinetic analysis in a cell-free system to determine the mode of inhibition of glycerol-3-phosphate dehydrogenase (GPDH; EC 1.1.1.8) by EGCG. GPDH catalyzes the beta-nicotinamide adenine dinucleotide (NADH)-dependent reduction of dihydroxyacetone phosphate (DHAP) to yield glycerol-3-phosphate, which serves as one of the major precursors of triacylglycerols. We found that EGCG dose-dependently inhibited GPDH activity at a concentration of approximately 20 muM for 50 % inhibition. The IC (50) values of other green tea catechins, such as (-)-epicatechin, (-)-epicatechin-3-gallate, and (-)-epigallocatechin, were all above 100 microM. This suggests a catechin type-dependent effect. Based on double-reciprocal plots of the kinetic data, EGCG was a noncompetitive inhibitor of the GPDH substrates, NADH and DHAP, with respective inhibition constants (Ki) of 18 and 31 microM. Results of this study possibly support previous studies that EGCG mediates fat content. Georg Thieme Verlag KG Stuttgart. New York.

  4. Kinetics and Mechanistic Studies on the Reaction between Cytochrome c and Tea Catechins

    Directory of Open Access Journals (Sweden)

    Lihua Wang

    2014-08-01

    Full Text Available Green tea is characterized by the presence of an abundance of polyphenolic compounds, also known as catechins, including epicatechin (EC, epigallocatechin (EGC, epicatechin gallate (EGC and epigallocatechin gallate (EGCG. In addition to being a popular beverage, tea consumption has been suggested as a mean of chemoprevention. However, its mode of action is unclear. It was discovered that tea catechins can react with cytochrome c. When oxidized cytochrome c was mixed with catechins commonly found in green tea under non-steady-state conditions, a reduction of cytochrome c was observed. The reaction rate of the catechins was dependent on the pH and the nature of the catechin. The pseudo-first order rate constant obtained increased in the order of EC < ECG < EGC < EGCG, which is consistent with previously reported superoxide reduction activities and Cu2+ reduction activities of tea catechins.

  5. Investigation of the Interaction Between Sodium(meta) Arsenite and Catechin via ESI Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    CUI Sheng-yun; WEN Jin-feng; KIM Seung-jin; LEE Yong-ill

    2007-01-01

    Catechin, one of the main components of green tea, is considered to have the remedy effect of arsenic poison,although the chemical mechanism is not well known. In this study, sodium(meta) selenite, which is used as herbisolution to investigate the interaction between toxic inorganic arsenic compound and catechin via ESI tandem mass spectrometry. The interaction products of mono-methylated arsenic with catechin in the presence of methanol were identified in the negative mode. Collission induced dissociation(CID) mass spectrometric measurements indicate that monomethylated arsenic was "alkylated" strongly by conjugation at the sites of C2' and C5' in the phenyl ring B of the catechin. The interaction mechanism between sodium(meta) arsenite and catechin was proposed. The results provide useful information to understand the chemical pathway of the detoxification of the arsenic toxicity by catechin.

  6. Pharmacokinetics of green tea catechins in extract and sustained-release preparations.

    Science.gov (United States)

    Janle, Elsa M; Morré, Dorothy M; Morré, D James; Zhou, Qin; Zhu, Yongxin

    2008-01-01

    Catechins are a major constituent of green tea. For green tea to have cancer therapeutic benefit, catechin concentrations in the range of 100 nM are required continuously until apoptosis (programmed cell death) is induced. To prolong elevated plasma and interstitial concentrations of catechins, a sustained-release formulation of green tea extract was tested and compared to a commercial green tea extract (Tegreen97®). Sustained-release formulations are usually developed in the pharmaceutical industry to slowly deliver the compound over a period of time and increase the dosing interval. Plasma and interstitial fluid (ISF) pharmacokinetics of catechins were determined following an oral dose in the rat. The sustained-release formulation profile included multiple smaller peaks of total catechins in both plasma and ISF. Interstitial fluid profiles of green tea extract indicate that higher catechins concentration and longer duration in tissue than in blood may make a sustained-release form unnecessary.

  7. Influence of the galloyl moiety in tea catechins on binding affinity for human serum albumin.

    Science.gov (United States)

    Minoda, Kanako; Ichikawa, Tatsuya; Katsumata, Tomoharu; Onobori, Ken-ichi; Mori, Taiki; Suzuki, Yukiko; Ishii, Takeshi; Nakayama, Tsutomu

    2010-01-01

    The major catechins of green tea extract are (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), and (-)-epigallocatechin gallate (EGCg). Recent research has indicated that catechins form complexes with human serum albumin (HSA) in blood, and differences in their binding affinity toward HSA are believed to modulate their bioavailability. In this study, we kinetically investigated the interaction between the catechins and HSA immobilized on a quartz-crystal microbalance (QCM). The association constants obtained from the frequency changes of QCM revealed interactions of ECg and EGCg with HSA that are 100 times stronger than those of EC and EGC. Furthermore, comparisons of these catechins by native-gel electrophoresis/blotting with redox-cycling staining revealed that, in a phosphate buffer, ECg and EGCg have a higher binding affinity toward HSA than EC and EGC. These observations indicate that catechins with a galloyl moiety have higher binding affinities toward HSA than catechins lacking a galloyl moiety.

  8. Kinetics and Mechanistic Studies on the Reaction between Cytochrome c and Tea Catechins

    OpenAIRE

    Lihua Wang; Elizabeth Santos; Desiree Schenk; Montserrat Rabago-Smith

    2014-01-01

    Green tea is characterized by the presence of an abundance of polyphenolic compounds, also known as catechins, including epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (EGC) and epigallocatechin gallate (EGCG). In addition to being a popular beverage, tea consumption has been suggested as a mean of chemoprevention. However, its mode of action is unclear. It was discovered that tea catechins can react with cytochrome c. When oxidized cytochrome c was mixed with catechins commonl...

  9. Pharmacokinetics of Green Tea Catechins in Extract and Sustained-Release Preparations

    OpenAIRE

    Janle, Elsa M; Morré, Dorothy M.; Morré, D. James; Zhou, Qin; Zhu, Yongxin

    2008-01-01

    Catechins are a major constituent of green tea. For green tea to have cancer therapeutic benefit, catechin concentrations in the range of 100 nM are required continuously until apoptosis (programmed cell death) is induced. To prolong elevated plasma and interstitial concentrations of catechins, a sustained-release formulation of green tea extract was tested and compared to a commercial green tea extract (Tegreen97®). Sustained-release formulations are usually developed in the pharmaceutical i...

  10. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins

    OpenAIRE

    Masami Suganuma; Atsushi Takahashi; Tatsuro Watanabe; Keisuke Iida; Takahisa Matsuzaki; Yoshikawa, Hiroshi Y.; Hirota Fujiki

    2016-01-01

    Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (−)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AF...

  11. Flavonoids from Agrimonia pilosa Ledeb: Free Radical Scavenging and DNA Oxidative Damage Protection Activities and Analysis of Bioactivity-Structure Relationship Based on Molecular and Electronic Structures

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    Liancai Zhu

    2017-02-01

    Full Text Available To clarify the substantial basis of the excellent antioxidant capacity of Agrimonia pilosa Ledeb. Fourteen flavonoids were isolated and identified from Agrimonia pilosa Ledeb, seven of which have notable DPPH radical scavenging activities, i.e., catechin, luteolin, quercetin, quercitrin, hyperoside, rutin, luteolin-7-O-β-glucoside with IC50 values of 5.06, 7.29, 4.36, 7.12, 6.34, 6.36 and 8.12 µM, respectively. The DNA nicking assay showed that five flavonoids from Agrimonia pilosa Ledeb—taxifolin, catechin, hyperoside, quercitrin and rutin—have good protective activity against DNA oxidative damage. Further, we analyzed the bioactivity-structure relationship of these 14 flavonoids by applying quantum theory. According to their O-H bond dissociation enthalpy (BDE, C ring’s spin density and stable molecular structure, the relationship between their structures and radical scavenging capacities was evaluated and clarified. We found that among flavonoid aglycones from Agrimonia pilosa Ledeb, the O-H BDE of quercetin is lowest with the values of 69.02 and the O-H BDE of apigenin is highest with the values of 79.77. It is interesting that the O-H BDE value of isovitexin (78.55 with glycoside at C-6 position is lower than that of its aglycone (79.77 and vitexin (99.20 with glycoside at C-8 position. Further analysis indicated that the glycosidation of flavonoids at C-6 in the A-ring makes a more uniform distribution of spin density and improves the stability of free radicals leading to the increase in antioxidant capacity. Flavonoids with good antioxidant capacity might contribute to the pharmacological effects of Agrimonia pilosa Ledeb.

  12. Absorption and pharmacokinetics of green tea catechins in beagles.

    Science.gov (United States)

    Mata-Bilbao, Maria de Lourdes; Andrés-Lacueva, Cristina; Roura, Elena; Jáuregui, Olga; Escribano, Elvira; Torre, Celina; Lamuela-Raventós, Rosa M

    2008-09-01

    The present study evaluates for the first time in dogs, the kinetics of green tea catechins and their metabolic forms in plasma and urine. Ten beagles were administered 173 mg (12.35 mg/kg body weight) of catechins as a green tea extract, in capsules. Blood samples were collected during 24 h after intake and urine samples were collected during the following periods of time: 0-2, 2-6, 6-8 and 8-24 h. Two catechins with a galloyl moiety and three conjugated metabolites were detected in plasma. Most of the detected forms in plasma reached their maximum plasma concentration (Cmax) at around 1 h. Median Cmax for ( - )-epigallocatechin-3-gallate (EGCG), ( - )-epicatechin-3-gallate (ECG), ( - )-epigallocatechin glucuronide (EGC-glucuronide), ( - )-epicatechin glucuronide (EC-glucuronide), ( - )-epicatechin sulphate (EC-sulphate) were 0.3 (range 0.1-1.9), 0.1 (range 0-0.4), 0.8 (range 0.2-3.9), 0.2 (range 0.1-1.7) and 1 (range 0.3-3.4) micromol/l, respectively. The areas under the plasma concentration v. time curves (AUC0 --> 24) were 427 (range 102-1185) micromol/l x min for EGC-glucuronide, 112 (range 53-919) micromol/l x min for EC-sulphate, 71 (range 26-306) micromol/l x min for EGCG, 40 (range 12-258) micromol/l x min for EC-glucuronide and 14 (range 0.1-124) micromol/l x min for ECG. The values of mean residence time (MRT0 --> 24) were 5 (range 2-16), 2 (range 1-11), 10 (range 2-13), 3 (range 2-16) and 2.4 (range 1-18) h for EGCG, ECG, EGC-glucuronide, EC-glucuronide and EC-sulphate, respectively. In urine, catechins were present as conjugated forms, suggesting bile excretion of EGCG and ECG. Green tea catechins are absorbed following an oral administration and EGC-glucuronide is the metabolic form that remains in the organism for a longer period of time, suggesting that this compound could suffer an enterohepatic cycle.

  13. Enzymatic synthesis of poly(catechin)-antibiotic conjugates: an antimicrobial approach for indwelling catheters.

    Science.gov (United States)

    Gonçalves, Idalina; Abreu, Ana S; Matamá, Teresa; Ribeiro, Artur; Gomes, Andreia C; Silva, Carla; Cavaco-Paulo, Artur

    2015-01-01

    Biofilm formation in urinary indwelling catheters is one of the most critical issues that patients face. Catheters were coated with poly(catechin)-antibiotic conjugates with enhanced antimicrobial properties. Catechin was conjugated with two antibiotics, namely trimethoprim (TMP) and sulfamethoxazole (SMZ) via activation with N,N'-disuccinimidyl carbonate (DSC) and subsequent coupling to molecules containing α-amine moieties. Silicone and polyurethane catheters were functionalized in situ through laccase oxidation of catechin-antibiotic conjugates. Four antimicrobial coatings were produced, namely with poly(catechin), poly(catechin)-TMP, poly(catechin)-SMZ and poly(catechin)-TMP-SMZ. The bacterial adhesion reduction was tested on the functionalized devices using gram-negative and gram-positive strains. The most significant reduction in adhesion was observed with poly(catechin)-TMP (gram-negative -85 % and gram-positive -87 %) and with poly(catechin)-TMP-SMZ (gram-negative -85 % and gram-positive -91 %). The cytotoxicity to mammalian cells was tested by indirect contact for 5 days and revealed that all the tested coatings supported more than 90 % of viable cells. A promising approach for the increase of the indwelling catheter lifespan was developed aiming to reduce catheter-associated chronic infections.

  14. Interaction and release of catechin from anhydride maleic-grafted polypropylene films.

    Science.gov (United States)

    López de Dicastillo, Carol; Castro-López, Maria Del Mar; Lasagabaster, Aurora; López-Vilariño, Jose M; González-Rodríguez, M Victoria

    2013-04-24

    In this paper, investigations were carried out on catechin-loaded maleic anhydride (MAH)-modified polypropylenes (PP). Two maleic-modified polypropylenes (PPMAH) with different maleic concentrations have been blended with PP and catechin to obtain composites of improved catechin retention with the aim of studying the possible interactions between these grafted polymers with antioxidants, and a secondary interest in developing an active antioxidant packaging. Composite physicochemical properties were measured by thermal analysis (thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and oxidation induction time (OIT)) and infrared spectroscopy studies. Catechin release profiles into food simulants were obtained by HPLC-PDA-QqQ, following European legislation. Antiradical activity of composites was analyzed by the ABTS and DPPH method. The formation of intermolecular hydrogen bonds between catechin and functionalized PP has been confirmed by Fourier transform infrared (FTIR) studies. Besides, a small fraction of ester bonds, formed as a result of a chemical reaction between a fraction of the hydrolyzed anhydride and the catechin hydroxyl groups, is not discarded. OIT results also showed an increase in antioxidant effectiveness caused by the presence of catechin- and maleic-modified PPMAH in the blend formulations. Incorporation of MAH-grafted PP increased substantially the retention rate of catechin, being dependent on the MAH content of the grafted polypropylene. The described interactions between catechin and maleic groups, together with changes in PP morphology in comparison with reference PP explained lower antioxidant release. Besides formulation, antioxidant release was dependent on the type of food, the temperature, and the time.

  15. Exploring the possible applications of catechin (gel for oral care of the elderly and disabled individuals

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    Muneaki Tamura

    2012-08-01

    Full Text Available The oral cavity contains more than hundreds of microbial species. An increase in the number of these microorganisms like high pathogenic potential species, such as cariogenic and periodontopathic bacteria, and the change of microbial biota may result in, not only oral infection, but also systemic diseases, such as infective endocarditis and aspiration pneumonia. It is very important to control the growth of these microorganisms and its biota just after oral cleaning in order to suppress disease onset. In this regard, it is useful to use the anti-microbial component which acts against pathogenic microorganisms. Here, we highlight the importance of catechin, and feature its possible oral, especially periodontal applications. By combining catechin with gel (catechin gel, antimicrobial activity of catechin was prolonged in gel and catechin anti-oxidization property was observed. Catechin gel inhibited the growth of the Actinomyces, periodontopathic bacteria and Candida strains tested, but did not inhibit that of the oral streptococci that are important in the normal oral flora. In contrast, commercially available moisture gels containing antimicrobial components showed antimicrobial activity against all of the tested strains including the oral streptococci. This show that catechin has selective antimicrobial activity, attributable to hydrogen peroxide production. This paper reviews previous works using catechin and, likewise, catechin gel may be show its possible oral application for prevent dental caries and periodontal disease.

  16. Investigate the binding of catechins to trypsin using docking and molecular dynamics simulation.

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    Fengchao Cui

    Full Text Available To explore the inhibitory mechanism of catechins for digestive enzymes, we investigated the binding mode of catechins to a typical digestive enzyme-trypsin and analyzed the structure-activity relationship of catechins, using an integration of molecular docking, molecular dynamics simulation and binding free energy calculation. We found that catechins with different structures bound to a conservative pocket S1 of trypsin, which is comprised of residues 189-195, 214-220 and 225-228. In the trypsin-catechin complexes, Asp189 by forming strong hydrogen bonding, and Gln192, Trp215 and Gly216 through hydrophobic interactions, all significantly contribute to the binding of catechins. The number and the position of hydroxyl and aromatic groups, the structure of stereoisomers, and the orientation of catechins in the binding pocket S1 of trypsin all affect the binding affinity. The binding affinity is in the order of Epigallocatechin gallate (EGCG > Epicatechin gallate (ECG > Epicatechin (EC > Epigallocatechin (EGC, and 2R-3R EGCG shows the strongest binding affinity out of other stereoisomers. Meanwhile, the synergic conformational changes of residues and catechins were also analyzed. These findings will be helpful in understanding the knowledge of interactions between catechins and trypsin and referable for the design of novel polyphenol based functional food and nutriceutical formulas.

  17. Investigate the binding of catechins to trypsin using docking and molecular dynamics simulation.

    Science.gov (United States)

    Cui, Fengchao; Yang, Kecheng; Li, Yunqi

    2015-01-01

    To explore the inhibitory mechanism of catechins for digestive enzymes, we investigated the binding mode of catechins to a typical digestive enzyme-trypsin and analyzed the structure-activity relationship of catechins, using an integration of molecular docking, molecular dynamics simulation and binding free energy calculation. We found that catechins with different structures bound to a conservative pocket S1 of trypsin, which is comprised of residues 189-195, 214-220 and 225-228. In the trypsin-catechin complexes, Asp189 by forming strong hydrogen bonding, and Gln192, Trp215 and Gly216 through hydrophobic interactions, all significantly contribute to the binding of catechins. The number and the position of hydroxyl and aromatic groups, the structure of stereoisomers, and the orientation of catechins in the binding pocket S1 of trypsin all affect the binding affinity. The binding affinity is in the order of Epigallocatechin gallate (EGCG) > Epicatechin gallate (ECG) > Epicatechin (EC) > Epigallocatechin (EGC), and 2R-3R EGCG shows the strongest binding affinity out of other stereoisomers. Meanwhile, the synergic conformational changes of residues and catechins were also analyzed. These findings will be helpful in understanding the knowledge of interactions between catechins and trypsin and referable for the design of novel polyphenol based functional food and nutriceutical formulas.

  18. Green tea formulations with vitamin C and xylitol on enhanced intestinal transport of green tea catechins.

    Science.gov (United States)

    Chung, Jae-Hwan; Kim, Sol; Lee, Sang-Jun; Chung, Jin-Oh; Oh, Yu-Jin; Shim, Soon-Mi

    2013-05-01

    The effect of green tea formulated with vitamin C and xylitol on intestinal cell transport of gallated and nongallated catechin was studied. The transport of catechins from both apical to basolateral and basolateral to apical directions was measured. The effect of vitamin C (4, 10, 20 ppm), xylitol (11, 27.5, 55 ppm), and combinations of both on the intestinal transport rate of catechins was examined. The efflux value (Pb→a/Pa→b) of (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-epicatechin (EC), and (-)-epicatechin gallate (ECG) was 0.26, 0.22, 1.22, and 0.17, respectively, indicating that EC appeared to be less absorbed compared with other catechins. The addition of xylitol (11, 27.5, 55 ppm) and vitamin C (4, 10, 20 ppm) and in combination enhanced transport rate of nongallated catechins such as EC and EGC. For EC, vitamin C was revealed to be the most effective on intestinal transport, implying the inhibition of the efflux transport mechanism of EC. Intestinal transport of gallated catechins significantly increased from catechins formulated with vitamin C and xylitol in a dose-dependent manner compared to the catechin-only formulation. Results provide a potential strategy to enhance the delivery and bioavailability of catechins in humans by modulating green tea formulation with vitamin C and xylitol.

  19. Differential behaviors of tea catechins under thermal processing: Formation of non-enzymatic oligomers.

    Science.gov (United States)

    Fan, Fang-Yuan; Shi, Meng; Nie, Ying; Zhao, Yue; Ye, Jian-Hui; Liang, Yue-Rong

    2016-04-01

    Tea catechins as a member of flavan-3-ols subclass with the same skeleton may behave differentially. This study investigated the chemical conversions of 8 catechins under heat treatment with the involvement of epimerization, hydrolysis and oxidation/condensation reactions. Three reactions were enhanced as temperature increased from 30 °C to 90 °C. The epimerization of non-gallated catechins was favored by epi-configuration but hindered by pyrogallol moiety, and the hydrolysis reaction of gallated catechins was facilitated by pyrogallol moiety. Epicatechin and epigallocatechin had the lowest thermostabilities due to epimerization and oxidation/condensation reactions respectively. Sufficient O2 was not a precondition for the occurrence of chemical conversions of catechins under heat treatment. Non-enzymatic oligomerization occurred to epi type catechins and catechin under heat treatment, and dehydrodicatechins A were mainly responsible for the browning of epicatechin and catechin solutions. The evidence of generation of catechin oligomers provides a novel way to explain sensory change of tea and relevant products during thermal processing.

  20. Effects of red wine flavonoid components on biomembranes and cell proliferation

    Directory of Open Access Journals (Sweden)

    Tsuchiya H

    2011-05-01

    Full Text Available Hironori TsuchiyaDepartment of Dental Basic Education, Asahi University School of Dentistry, Mizuho, Gifu, JapanBackground: In order to understand the antiproliferative effect of red wine in mechanistic terms, the membrane interactions of flavonoid components and their related structures were compared using liposomal biomimetic membranes prepared with different phospholipids and cholesterol.Methods and results: A series of fluorescence polarization measurements revealed that anthocyanidins, flavones, flavonols, flavanones, flavanonols, isoflavones, catechins, and chalcones interact with biomimetic membranes in a structure-dependent manner to decrease their fluidity at concentrations of 1–10 µM by preferentially acting in the deeper regions of the lipid bilayers. In the structure and membrane interactivity relationship, greater membrane-interacting potency was associated with a 3-hydroxyl group and a double bond between the 2-carbon and 3-carbon of the C ring, 3’,4’-dihydroxyl groups of the B ring, and 5,7-dihydroxyl groups of the A ring. Cyanidin, quercetin, and (–-epigallocatechin gallate meet these structural requirements, and were effective in inhibiting the proliferation of tumor cells, showing inhibition rates of 16.4% and 35.4%, 23.3% and 74.3%, and 31.3% and 75.5%, respectively, after culture for 24 and 48 hours. These antiproliferative flavonoids simultaneously decreased the membrane fluidity of tumor cells depending on culture time. The rank order of cell membrane rigidification [(–-epigallocatechin gallate > quercetin > cyanidin] was consistent with inhibition of cell proliferation.Conclusion: Membrane interaction is very likely to underlie the antiproliferative effects of wine flavonoids. Membrane-interactive flavonoid components would contribute to the functionality of red wine.Keywords: red wine, flavonoid, membrane interaction, fluidity change, antiproliferative effect

  1. Low blood sugar - newborns

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007306.htm Low blood sugar - newborns To use the sharing features on this page, please enable JavaScript. A low blood sugar level in newborn babies is also called neonatal ...

  2. Oral green tea catechins transiently lower plasma glucose concentrations in female db/db mice.

    Science.gov (United States)

    Wein, Silvia; Schrader, Eva; Rimbach, Gerald; Wolffram, Siegfried

    2013-04-01

    Polyphenols, including green tea catechins, are secondary plant compounds often discussed in the context of health-promoting potential. Evidence for such effects is mainly derived from epidemiological and cell culture studies. The aim of the present study was to investigate antidiabetic, antiadipogenic, and anti-inflammatory effects at nonpharmacological doses in an obese diabetic mouse model that exerts early relevant clinical signs of non-insulin-dependent diabetes mellitus. Female db/db mice received a flavonoid-poor diet either without additive, with rosiglitazone (RSG, 0.02 g/kg diet), or with green tea extract (low-dose green tea extract [LGTE] and high-dose green tea extract [HGTE], 0.1 and 1 g/kg diet). Food and water were freely available. The body weight was monitored weekly. Blood was sampled (12-h fasted) from the tail vein on day 28 and analyzed for glucose, cholesterol, triacylglycerol, nonesterified fatty acids, insulin, adiponectin, and soluble intercellular adhesion molecule-1 (sICAM-1). Blood glucose was also analyzed on day 14. Furthermore, sICAM-1 release was investigated in tumor necrosis factor alpha-stimulated EAhy926 cells. After 14 days, fasting glycemia was improved by RSG or HGTE supplementation compared to controls. However, at the end of the study (day 28), only RSG exhibited glucose-lowering effects and induced plasma adiponectin concentrations, paralleled by higher body weight gain and reduced periuterine fat pads compared to controls. However, only GTE treatment reduced sICAM-1 release in vitro and in vivo. Nonpharmacological HGTE supplementation in db/db mice caused (1) no adiponectin-inducing or antiadipogenic effects, (2) reduced sICAM-1 release, thereby potentially exerting anti-inflammatory effects in the progressive diabetic state, and (3) a transient improvement in glycemia.

  3. Monitoring Blood Sugar: The Importance of Checking Blood Sugar Levels

    Science.gov (United States)

    ... to Be Smart About Social Media Monitoring Blood Sugar KidsHealth > For Parents > Monitoring Blood Sugar Print A ... Tests Record Keeping The Importance of Checking Blood Sugar Levels Besides helping to keep blood sugar levels ( ...

  4. Monitoring Blood Sugar: The Importance of Checking Blood Sugar Levels

    Science.gov (United States)

    ... Feeding Your 1- to 2-Year-Old Monitoring Blood Sugar KidsHealth > For Parents > Monitoring Blood Sugar A ... Other Tests Record Keeping The Importance of Checking Blood Sugar Levels Besides helping to keep blood sugar ...

  5. Extraction, Identification and Quantitative HPLC Analysis of Flavonoids From Fruit Extracts of Arbutus unedo L from Tiaret Area (Western Algeria

    Directory of Open Access Journals (Sweden)

    Khadidja Bouzid

    2014-12-01

    Full Text Available The aim of the current study was to evaluate the total phenolic, flavonoid content and to investigate the antioxidant capacities of the fruit extracts of Arbutus unedo L. that grows in Tiaret area (Western Algeria. First we have extracted the fruit by some non-polar solvent (chloroform, ethyl acetate, 1-butanol. Total phenolic content and total flavonoid content were evaluated according to the Folin-Ciocalteu procedure, and a colorimetric method, respectively. Extracts content was determined by using a high-performance liquid chromatography (HPLC-UV method. The total phenolic contents of A.unedo L. varied between 12.75±0.06 to 34.17±1.36 mg gallic acid equivalent/g of dry weight of extract. The total flavonoid varied from 2.18±0.10 to 6.54±1.14 mg catechin equivalent/g. The antioxidant potential of all extracts was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging activity, the IC50 of acetate ethyl was the best by 0,009 mg/ml may due to the phenolic compound, in the second was the chloroform extract by IC50=0,015mg/ml, in the third was butanol extract by IC50= 0,022 mg/ml and in the last was water extract by IC50= 0,048mg/ml. the antioxidant activity of all extracts was better than ascorbic acid. The extract obtained under optimum conditions was analyzed by HPLC and five flavonoid compounds were identified; they are catechin, apiginin, silybin, fisetine and naringin.

  6. An analysis on flavonoids contents in Mao Luang fruits of fifteen cultivars (Antidesma bunius), grown in northeast Thailand.

    Science.gov (United States)

    Butkhup, L; Samappito, S

    2008-04-01

    This investigation was carried out at the Department of Biotechnology, Faculty of Technology, Mahasarakham University, Mahasarakham Province, Northeast Thailand. The study aimed to analyze flavonoids contents in ripe fruits of fifteen Mao Luang cultivars (Antidesma bunius) harvested from dipterocarp forest of the mountainous areas of Phupan Valley, Sakon Nakhon Province, Northeast Thailand. The experiment was laid in a Completely Randomised Design (CRD) with five replications. The fifteen cultivars were used as treatments. An amount of 2 kg of ripe fruits of each cultivar was collected and extracted for juice solutions. The analysis was carried out with the use of RP-HPLC laboratory system. The results showed that fruits of the fifteen Mao Luang cultivars contained three different kinds of flavonoids, i.e., catechin, procyanidin B1 and procyanidin B2. These three chemical compounds were the major flavonoids in all analyzed fruit samples of the fifteen cultivars. The highest amount of procyanidin B1 was found with Lompat followed by Maeloogdog with values of 4122.75 and 3993.88 mg 100 g(-1) of fresh weight, respectively and the highest amount of procyanidin B2 was found with Sangkrow 2 followed by Fapratan with values of 5,006.39 and 3,689.42 mg 100 g(-1) of fresh weight, respectively. Catechin contents in fruits of the fifteen cultivars varied from 73.39 to 316.22 mg 100 g(-1) of fresh weight for Sangkrow 5 and Fapratan, respectively where Fapratan was the highest among the fifteen cultivars followed by Sangkrow 2 with values of 316.22 and 175.40 mg 100 g(-1) of fresh weight, respectively. In terms of grand total amounts of flavonoids, Sangkrow 2 was the best followed by Fapratan, Sangkrow 1 and Maeloogdog, whilst the rest were of secondary importance.

  7. Hydrophobic sugar holograms

    Science.gov (United States)

    Mejias-Brizuela, N. Y.; Olivares-Pérez, A.; Páez-Trujillo, G.; Hernández-Garay, M. P.; Fontanilla-Urdaneta, R.; Fuentes-Tapia, I.

    2008-02-01

    The sugar matrix is used to record of phase holograms; it was modified with the purpose of obtaining a hydrophobic material to improve the stability of the registered image and to stimulate the photosensitivity of the sugar. The new material is formed by a sugar, pectin and vanillin dissolution. The diffraction efficiency parameter increases in comparison with only the sugar matrix, obtaining already of 10%.

  8. Flavonoid transport across RBE4 cells: A blood-brain barrier model.

    Science.gov (United States)

    Faria, Ana; Pestana, Diogo; Teixeira, Diana; Azevedo, Joana; De Freitas, Victor; Mateus, Nuno; Calhau, Conceição

    2010-06-01

    There is a growing interest in dietary therapeutic strategies to combat oxidative stress-induced damage to the Central Nervous System (CNS), which is associated with a number of pathophysiological processes, including Alzheimer's and Parkinson's diseases and cerebrovascular diseases. Identifying the mechanisms associated with phenolic neuroprotection has been delayed by the lack of information concerning the ability of these compounds to enter the CNS. The aim of this study was to evaluate the transmembrane transport of flavonoids across RBE-4 cells (an immortalized cell line of rat cerebral capillary endothelial cells) and the effect of ethanol on this transport. The detection and quantification of all of the phenolic compounds in the studied samples (basolateral media) was performed using a HPLC-DAD (Diode Array Detector). All of the tested flavonoids (catechin, quercetin and cyanidin-3-glucoside) passed across the RBE-4 cells in a time-dependent manner. This transport was not influenced by the presence of 0.1% ethanol. In conclusion, the tested flavonoids were capable of crossing this blood-brain barrier model.

  9. Flavonoids and coumarins from Hieracium pilosella L. (Asteraceae

    Directory of Open Access Journals (Sweden)

    Tadeusz Krzaczek

    2011-04-01

    Full Text Available Typical chromatographic methods were successfully applied to isolate nine flavonoid compounds and two coumarin glycosides from the inflorescences and the herb of Hieracium pilosella L. Repeated column chromatography, occasionally paper chromatography and recrystallization made the separation of three flavonoid aglycones and six glycosides - possible. Coumarin glycosides were isolated by preparative thin layer chromatography. Subsequent UV, NMR and MS analyses have led to identification of the following flavonoid derivatives: known for the species - apigenin, luteolin, luteolin 7-O- ß-glucopyranoside, luteolin 4’-O-ß-glucopyranoside, isoetin 7-O-ß- -glucopyranoside, isoetin 4’-O-ß-glucuronide and new for the species – kaempferol 3-methyl ether and apigenin 7-O-ß-glucopyranoside. Third isoetin glycoside contained two different sugar moieties: xylose and glucose, probably attached to the hydroxyl groups at C-4’ or C-4’ and C-2’(or 5’ of an aglycone. Umbelliferone 7-O-ß-glucopyranoside (skimmin and new for the genus Hieracium esculetin 7-O-ß-glucopyranoside (cichoriin were determined by NMR and MS methods.

  10. Distribution of flavonoids in the Myristicaceae.

    Science.gov (United States)

    Valderrama, J C

    2000-11-01

    During the past two decades the study of the Myristicaceae species has increased, and many flavonoids of different types have been isolated. This review discusses the flavonoids presently known in the Myristicaceae.

  11. Flavonoids from Lysidice rhodostegia Hance

    Institute of Scientific and Technical Information of China (English)

    Song GAO; Guang-Miao FU; Li-Hua FAN; Shi-Shan YU; De-Quan YU

    2005-01-01

    A novel flavonoid named mopanolchin (1), together with seven known flavonoids, was isolated by various chromatographic techniques and spectroscopic methods from the EtOAc extract of the roots of Lysidice rhodostegia Hance. The structure of the new compound was elucidated as 1"-(4-hydroxy-3, 5-dimethoxy)phenyl-2"-hydroxymethyl-dioxino [4', 5',1", 2"]mopanol (1) on the basis of spectral analysis.The known compounds were identified as (-)-epicatechin-3-O-gallate (2), epicatechin (3), naringenin (4),eriodictyol (5), luteolin (6), 7, 3', 4'-trihydroxyflavone (7) and (-)-robinetinidol (8).

  12. Monitoring Your Blood Sugar Level

    Science.gov (United States)

    ... Loss and Diet Plans Nutrients and Nutritional Info Sugar and Sugar Substitutes Exercise and Fitness Exercise Basics Sports Safety ... Loss and Diet Plans Nutrients and Nutritional Info Sugar and Sugar Substitutes Exercise and Fitness Exercise Basics ...

  13. Sugar exported: sugar packed in containers

    Directory of Open Access Journals (Sweden)

    José Alberto Yemal

    2010-04-01

    Full Text Available This paper presents a study in the port sector specialized in handling of bagged sugar. Sugar has always been exported in bags of 50 kg, placed directly in the holds of ships for general cargo. It appears that this form of transport has become obsolete now, the market for the direct form of transport of sugar packed in containers. Companies involved in this type of port handling need understand the reasons that are influencing this new mode of transportation as a way to fit and remain active and competitive in the industry.

  14. More Flavor for Flavonoid-Based Interventions?

    Science.gov (United States)

    Kaakoush, Nadeem O; Morris, Margaret J

    2017-04-01

    Poor diets are associated with obesity and a decline in cognitive function. Flavonoids are plant compounds that have been associated with improved metabolic parameters in obesity and reversal of cognitive decline. Given that microbial flavonoid conversion is important for bioactivity, flavonoid-derived neuroactive compounds may be functionally crucial in the gut microbiome-brain axis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Modification of flavonoid biosynthesis in crop plants

    NARCIS (Netherlands)

    Schijlen, E.G.W.M.; Vos, de C.H.; Tunen, van A.J.; Bovy, A.G.

    2004-01-01

    Flavonoids comprise the most common group of polyphenolic plant secondary metabolites. In plants, flavonoids play an important role in biological processes. Beside their function as pigments in flowers and fruits, to attract pollinators and seed dispersers, flavonoids are involved in UV-scavenging,

  16. Modification of flavonoid biosynthesis in crop plants

    NARCIS (Netherlands)

    Schijlen, E.G.W.M.; Vos, de C.H.; Tunen, van A.J.; Bovy, A.G.

    2004-01-01

    Flavonoids comprise the most common group of polyphenolic plant secondary metabolites. In plants, flavonoids play an important role in biological processes. Beside their function as pigments in flowers and fruits, to attract pollinators and seed dispersers, flavonoids are involved in UV-scavenging,

  17. Stability of Green Tea Catechins in Commercial Tea Leaves during Storage for 6 Months

    Science.gov (United States)

    To help meet the needs of consumers, producers of dietary tea products, and researchers for information on health-promoting tea ingredients, we determined by HPLC seven catechins [(–)-epigallocatechin (EGC), (–)-catechin (C), (+)-epicatechin (EC), (–)-epigallocatechin 3-gallate (EGCG), (–)-gallocate...

  18. Sorption of catechins under conditions of reverse-phase high-efficiency liquid chromatography

    Science.gov (United States)

    Shafigulin, R. V.; Egorova, K. V.; Bulanova, A. V.

    2010-08-01

    The physico-chemical principles of catechin sorption from various polar solvents onto silica gel modified with octadecyl groups were studied. Thermodynamic characteristics of the sorption were calculated, and the applicability of different models of retention was demonstrated for catechins under the conditions of reverse-phase high-efficiency liquid chromatography.

  19. Polymerization of catechin catalyzed by Mn-, Fe- and Al-oxides.

    Science.gov (United States)

    Chen, Yue Min; Tsao, Tsung Ming; Liu, Cheng Chung; Huang, Pan Ming; Wang, Ming Kuang

    2010-11-01

    The role of short-range order (SRO) metal oxides, which are common in acid soils and associated environments, in influencing the abiotic transformations of catechin, which is common in the soil of tea plantations, still remains poorly understood. The aim of this study was to investigate the catalytic power of SRO Mn(IV)-, Fe(III)- and Al-oxides in influencing the abiotic transformations of catechin. At the end of a 90-h reaction period, the release of CO(2) in all the oxide-catechin systems is higher than that for the system with only catechin. Polymerization of catechin is catalyzed and enhanced by SRO-oxides, as is indicated by the absorbance values of the supernatants, which were obtained via visible adsorption spectroscopy, and the yields of humic polymers. The sequence of the oxides that increased the yield of total humic polymers in these systems under ambient atmosphere is: Fe(III)-oxide>Mn(IV)-oxide>Al-oxide>no catalyst (catechin). The electron spin resonance (ESR) and Fourier transformation infrared absorption spectrometry (FT-IR) of humic polymers formed in the oxide-catechin systems were similar to the spectra obtained from the humic polymers extracted from the soil. The catalytic power of SRO-oxides in promoting the oxidative polymerization of catechin, the resultant formation of humic substances, and C turnover in acid soils thus merit attention. Copyright (c) 2010. Published by Elsevier B.V.

  20. pH-dependent radical scavenging capacity of green tea catechins

    NARCIS (Netherlands)

    Muzolf, M.; Szymusiak, H.; Gliszczynska-Swiglo, A.; Rietjens, I.M.C.M.; Tyrakowska, B.

    2008-01-01

    The effect of pH on the radical scavenging capacity of green tea catechins was investigated using experimental as well as theoretical methods. It was shown that the radical scavenging capacity of the catechins, quantified by the TEAC value, increases with increasing pH of the medium. Comparison of t

  1. Interaction of green tea catechins with breast cancer endocrine treatment: a systematic review.

    Science.gov (United States)

    Yiannakopoulou, Eugenia C

    2014-01-01

    Recent data have shown strong chemopreventive and possibly cancer chemotherapeutic effects of green tea polyphenols and EGCG against breast cancer. This systematic review aims to synthesize data on the possible interaction of green tea catechins with breast cancer endocrine treatment. Electronic databases were searched with the appropriate search terms. Experimental trials suggest a synergistic interaction of green tea catechins with tamoxifen or raloxifene in the treatment of estrogen receptor-positive and estrogen receptor-negative breast cancer through estrogen receptor-dependent and -independent mechanisms. No evidence of an interaction of green tea catechins with aromatase inhibitors or fulvestrant has been reported. As green tea catechins are natural compounds with a rather favorable safety profile, the strategy of co-administrating green tea catechins with tamoxifen seems to be a rational approach in chemoprevention, adjuvant and metastatic breast cancer treatment that needs further investigation.

  2. Green tea catechins: biologic properties, proposed mechanisms of action, and clinical implications.

    Science.gov (United States)

    Rosen, Ted

    2012-11-01

    Botanical products, including and especially green tea leaves, have a wide range of both reputed and demonstrated health benefits and have been used medicinally for thousands of years. This paper focuses on green tea catechins, principally reviewing their known biologic properties and potential mechanisms of action (MOAs). The primary objective is to discuss the proposed antiviral, antiproliferative, and immunostimulatory activity of catechins based on strong evidence from in vitro and in vivo studies conducted to date, including two preclinical in vitro studies with sinecatechins, a proprietary mixture of catechins. This review also discusses the clinical implications of catechins for the treatment of external genital and perianal warts (EGWs) and other conditions caused by human papillomavirus (HPV). While the MOA of catechins in the treatment of EGWs and other HPV-related conditions may be related to or associated with postulated or proven antiviral and immunostimulatory activity, the precise clinical significance of the various in vitro findings remains largely unknown.

  3. Dietary Flavonoids and Acarbose Synergistically Inhibit alpha-Glucosidase and Lower Postprandial Blood Glucose.

    Science.gov (United States)

    Zhang, Bowei; Li, Xia; Sun, Wenlong; Xing, Yan; Xiu, Zhilong; Zhuang, Chunlin; Dong, Yuesheng

    2017-09-06

    The inhibition of porcine pancreatic α-amylase and mammalian α-glucosidase by sixteen individual flavonoids was determined. The IC50 values for baicalein, (+)-catechin, quercetin, and luteolin were 74.1 ± 5.6, 175.1 ± 9.1, 281.2 ± 19.2, and 339.4 ± 16.3 μM, respectively, against α-glucosidase. The IC50 values for apigenin and baicalein were 146.8 ± 7.1 and 446.4 ± 23.9 μM, respectively, against α-amylase. The combination of baicalein, quercetin or luteolin with acarbose showed synergistic inhibition, and the combination of (+)-catechin with acarbose showed antagonistic inhibition of α-glucosidase. The combination of baicalein or apigenin with acarbose showed additive inhibition of α-amylase at lower concentrations and antagonistic inhibition at a higher concentration. Kinetic studies of α-glucosidase activity revealed that baicalein alone, acarbose alone, and the combination showed non-competitive, competitive, and mixed-type inhibition, respectively. Molecular modeling revealed that baicalein had higher affinity to the non-competitive binding site of maltase, glucoamylase, and isomaltase subunits of α-glucosidase, with glide scores of -7.64, -6.98, and -6.88, respectively. (+)-Catechin had higher affinity to the active sites of maltase and glucoamylase and to the non-competitive site of isomaltase. After sucrose loading, baicalein dose-dependently reduced the postprandial blood glucose (PBG) level in mice. The combination of 80 mg/kg baicalein and 1 mg/kg acarbose synergistically lowered the level of PBG, and the hypoglycemic effect was comparable to 8 mg/kg acarbose. The results indicated that baicalein could be used as a supplemental drug or dietary supplement in dietary therapy for diabetes mellitus.

  4. Reproductive and developmental outcomes, and influence on maternal and offspring tissue mineral concentrations, of (−-epicatechin, (+-catechin, and rutin ingestion prior to, and during pregnancy and lactation in C57BL/6J mice

    Directory of Open Access Journals (Sweden)

    Mary N.R. Lesser

    2015-01-01

    Full Text Available Maternal nutrition can have a significant effect on developmental processes during pregnancy and lactation. While certain flavonoids have been postulated to be beneficial for health, little is known about the effects of ingestion during pregnancy and lactation on the mother and progeny. We report on the effects of maternal consumption of high levels of certain flavonoids on reproductive and developmental outcomes in a mouse model. C57BL/6J female mice were fed a control diet (CT, the CT diet supplemented with 1% or 2% of a mix of epicatechin and catechin (EC1, EC2, or rutin (RU1, RU2 prior to, during pregnancy, and lactation. A subset of dams was killed on gestation day (GD 18.5 to evaluate fetal outcomes and the remainder was allowed to deliver to evaluate offspring. Maternal food intake, body and tissue weight did not differ among groups. The number of resorptions, implantations, litter size, postnatal survival, body weight, and skeletal development were also similar. Alterations in maternal and offspring liver mineral concentrations were observed. The current results indicate that consumption of high amounts of epicatechin, catechin, and rutin during gestation and lactation is not associated with any marked developmental effects, although changes in liver mineral concentrations were noted.

  5. Ambivalent role of gallated catechins in glucose tolerance in humans: a novel insight into non-absorbable gallated catechin-derived inhibitors of glucose absorption.

    Science.gov (United States)

    Park, J H; Jin, J Y; Baek, W K; Park, S H; Sung, H Y; Kim, Y K; Lee, J; Song, D K

    2009-12-01

    Prolonged postprandial hyperglycemia is a detrimental factor for type 2 diabetes and obesity. The benefit of green tea extract (GTE) consumption still requires confirmation. We report the effects of circulating green tea catechins on blood glucose and insulin levels. Oral glucose loading 1 h after GTE ingestion in humans led to higher blood glucose and insulin levels than in control subjects. Gallated catechins were required for these effects, although within the intestinal lumen they have been known to decrease glucose and cholesterol absorption. Treatment with epigallocatechin-3-gallate hindered 2-deoxyglucose uptake into liver, fat, pancreatic beta-cell, and skeletal muscle cell lines. The glucose intolerance was ameliorated by gallated catechin-deficient GTE or GTE mixed with polyethylene glycol, which was used as an inhibitor of intestinal absorption of gallated catechins. These findings may suggest that the gallated catechin when it is in the circulation elevates blood glucose level by blocking normal glucose uptake into the tissues, resulting in secondary hyperinsulinemia, whereas it decreases glucose entry into the circulation when they are inside the intestinal lumen. These findings encourage the development of non-absorbable derivatives of gallated catechins for preventative treatment of type 2 diabetes and obesity, which would specifically induce only the positive luminal effect.

  6. Protective effect of catechin in type I Gaucher disease cells by reducing endoplasmic reticulum stress

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yea-Jin [Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, 336-795 (Korea, Republic of); Kim, Sung-Jo, E-mail: sungjo@hoseo.edu [Department of Biotechnology, Hoseo University, Baebang, Asan, Chungnam, 336-795 (Korea, Republic of); Heo, Tae-Hwe, E-mail: thhur92@catholic.ac.kr [College of Pharmacy, The Catholic University of Korea, Bucheon 420-743 (Korea, Republic of)

    2011-09-23

    Highlights: {yields} Catechin reduces the expression level of ER stress marker protein in type I Gaucher disease cells. {yields} Catechin induces the proliferation rate of GD cells similar levels to normal cells. {yields} Catechin improves wound healing activity. {yields} Catechin-mediated reductions in ER stress may be associated with enhanced cell survival. {yields} We identified catechin as a protective agent against ER stress in GD cells. -- Abstract: Gaucher disease (GD) is the most common lysosomal storage disorder (LSD) and is divided into three phenotypes, I, II, and III. Type I is the most prevalent form and has its onset in adulthood. The degree of endoplasmic reticulum (ER) stress is one of the factors that determine GD severity. It has recently been reported that antioxidants reduce ER stress and apoptosis by scavenging the oxidants that cause oxidative stress. For this report, we investigated the possibility that catechin can act on type I GD patient cells to alleviate the pathogenic conditions of GD. We treated GD cells with catechin and examined the expression level of GRP78/BiP (an ER stress marker) by western blots and fluorescence microscopy, the proliferation rate of GD cells, and scratch-induced wound healing activity. Our results show that catechin reduces the expression level of GRP78/BiP, leads to cell proliferation rates of GD cells similar levels to normal cells, and improves wound healing activity. We conclude that catechin protects against ER stress in GD cells and catechin-mediated reductions in ER stress may be associated with enhanced cell survival.

  7. Cancer chemoprevention with green tea catechins: from bench to bed.

    Science.gov (United States)

    Shirakami, Yohei; Shimizu, Masahito; Moriwaki, Hisataka

    2012-12-01

    Many epidemiological studies and a large number of experimental studies using a variety of animal models have observed that consumption or administration of green tea appears to exert cancer chemopreventive activity. Based on the results of numerous laboratory cell culture investigations, several mechanisms have been hypothesized to underlie the anti-cancer activity of green tea catechins, especially that of (-)-epigallocatechin-3-gallate (EGCG), the most abundant and active constituent in green tea. These mechanisms include promotion of anti-oxidant activity, inhibition of NF-κB and AP-1, regulation of the cell cycle, inhibition of receptor tyrosine kinase pathways, control of epigenetic modifications, and modulation of the immune system. Several recent interventional studies examining the anti-carcinogenic properties of green tea catechins in humans have yielded promising results that suggest the possibility of their application to human clinical trials. This review article analyzes the results of these studies to explicate the effects of consumption or administration of green tea and its constituents on malignancies observed to date and discuss future directions in this research field.

  8. Short communication: Effects of oral flavonoid supplementation on the metabolic and antioxidative status of newborn dairy calves.

    Science.gov (United States)

    Maciej, J; Schäff, C T; Kanitz, E; Tuchscherer, A; Bruckmaier, R M; Wolffram, S; Hammon, H M

    2016-01-01

    Scientific proof for flavonoids as a health tool in calf nutrition is inconsistent. We investigated the effects of the most abundant flavonoid, quercetin, and of a green tea extract (GTE) containing various catechins on the metabolic and antioxidative traits in dairy calves to clarify their potential health-promoting effects. Male newborn German Holstein calves (n=7 per group) received either no flavonoid (control group), 10mg of quercetin equivalents as quercetin aglycone or as rutin/kg of body weight (BW) per day, or 10mg/kg of BW per day of a GTE from d 2 to 26 of life. The supplements were provided with the morning and evening feeding. The calves were fed colostrum and milk replacer, and BW, feed intake, and health status were evaluated daily. Blood samples were collected from a jugular vein on d 1, 5, 12, 19, and 26 before the morning feeding to investigate the metabolic and antioxidative status of the calves. The growth performance and health status remained unchanged, but the GTE-fed calves had fewer loose feces than the controls. The plasma concentrations of quercetin changed over time and were higher in the rutin-fed group than in the control group, whereas the catechins were below the detection limit. The plasma Trolox equivalent antioxidative capacity and ferric reducing ability of plasma were measured as markers for plasma antioxidative capacity. The concentrations of Trolox equivalent antioxidative capacity increased, whereas ferric reducing ability of plasma decreased after the first day of life in all the groups. The oxidative stress markers in the plasma were measured as thiobarbituric acid reactive substances and F2-isoprostanes, but these did not indicate treatment or time effects. The plasma concentrations of total protein, albumin, urea, lactate, glucose, and nonesterified fatty acids and of insulin and cortisol varied over time, but no group differences were caused by the flavonoid supplementation. In summary, orally administered quercetin and

  9. Antioxidant Activity of Flavonoids Isolated From the Fruits of Xylopia parviflora (A. Rich. Benth

    Directory of Open Access Journals (Sweden)

    AT Tchinda

    2014-10-01

    Full Text Available The present study evaluates the antioxidant activity of the different flavonoids of the fruits of Xylopia parviflora used in Cameroon as spice in common traditional dishes. The fruits were successively extracted with hexane and methanol. The isolation of flavonoids was guided by the DPPH-TLC technique. The methanol crude extract and isolated compounds were screened for antioxidant and free radical scavenging activities using DPPH radical-scavenging, β-carotene/linoleic acid and ferric reducing antioxidant power (FRAP assays. The total phenolic content of the methanol crude extract was determined by Folin–Ciocalteu method. The DPPH-TLC technique led to the isolation of (+-catechin (1, kaempferol 3-O-arabinofuranoside (2 and quercetin 3-O-arabinofuranoside (3 identified by NMR and mass spectra analysis. In the colorimetric DPPH test, compound 1 had the same activity (EC50 8.1µg/ml as butylated hydroxytoluene (BHT used as standard while compound 3 and the methanol crude extract were less active (EC50 17.2µg/ml. Compound 2 was completely inactive. The total phenolic content of the fruit extracts was 113.03 mg gallic acid equivalents per g of extract. In the carotene bleaching test at the highest concentration of 100µg/mL, the order of inhibition of β-carotene discoloration was BHT > crude extract > quercetin 3-O-arabinofuranoside (3 > catechin (1 > kaempferol 3-O- arabinofuranoside (2. In the reducing power assay, compound 3 was more active at concentrations 40-100µg/mL. The HPLC analysis of the methanol crude extract revealed the presence of compounds 1-3 and unidentified phenolic compounds. The antioxidant activity of the methanol extract is probably due to the presence of compounds 1 and 3.

  10. Sugar - a harmless indulgence?

    DEFF Research Database (Denmark)

    Rasmussen, Lone Banke; Andersen, Niels Lyhne; Ovesen, L.

    1998-01-01

    The consumption of sugar is relatively high in Denmark - and other industrial countries - and many persons have a consumption which exceeds the recommended level of maximally 10% of energy intake. A high sugar consumption may reduce the nutrient density of the diet and increase the risk of vitamin...... and mineral deficiency, especially in low energy consumers. The sugar intake and the fat intake, expressed as percentage of energy, usually show an inverse association. This has lead to the statement that a diet with both a low sugar content and a low fat content is incompatible, but we will argue...... that this is not the fact. The significance of sugar for the development of obesity is not clarified. A high fat content in the diet seems to promote the development of obesity, while a high carbohydrate content tends to reduce obesity. It is not known if sugar in this connection is comparable to the other carbohydrates...

  11. Sugar - a harmless indulgence?

    DEFF Research Database (Denmark)

    Rasmussen, Lone Banke; Andersen, Niels Lyhne; Ovesen, L.

    1998-01-01

    and mineral deficiency, especially in low energy consumers. The sugar intake and the fat intake, expressed as percentage of energy, usually show an inverse association. This has lead to the statement that a diet with both a low sugar content and a low fat content is incompatible, but we will argue...... that this is not the fact. The significance of sugar for the development of obesity is not clarified. A high fat content in the diet seems to promote the development of obesity, while a high carbohydrate content tends to reduce obesity. It is not known if sugar in this connection is comparable to the other carbohydrates......The consumption of sugar is relatively high in Denmark - and other industrial countries - and many persons have a consumption which exceeds the recommended level of maximally 10% of energy intake. A high sugar consumption may reduce the nutrient density of the diet and increase the risk of vitamin...

  12. Fine-tuning of the flavonoid and monolignol pathways during apple early fruit development.

    Science.gov (United States)

    Baldi, Paolo; Moser, Mirko; Brilli, Matteo; Vrhovsek, Urska; Pindo, Massimo; Si-Ammour, Azeddine

    2017-05-01

    A coordinated regulation of different branches of the flavonoid pathway was highlighted that may contribute to elucidate the role of this important class of compounds during the early stages of apple fruit development. Apple (Malus × domestica Borkh.) is an economically important fruit appreciated for its organoleptic characteristics and its benefits for human health. The first stages after fruit set represent a very important and still poorly characterized developmental process. To enable the profiling of genes involved in apple early fruit development, we combined the suppression subtractive hybridization (SSH) protocol to next-generation sequencing. We identified and characterized genes induced and repressed during fruit development in the apple cultivar 'Golden Delicious'. Our results showed an opposite regulation of genes coding for enzymes belonging to flavonoid and monolignol pathways, with a strong induction of the former and a simultaneous repression of the latter. Two isoforms of phenylalanine ammonia-lyase and 4-coumarate:CoA ligase, key enzymes located at the branching point between flavonoid and monolignol pathways, showed opposite expression patterns during the period in analysis, suggesting a possible regulation mechanism. A targeted metabolomic analysis supported the SSH results and revealed an accumulation of the monomers catechin and epicatechin as well as several forms of procyanidin oligomers in apple fruitlets starting early after anthesis, together with a decreased production of other classes of flavonoids such as some flavonols and the dihydrochalcone phlorizin. Moreover, gene expression and metabolites accumulation of 'Golden Delicious' were compared to a wild apple genotype of Manchurian crabapple (Malus mandshurica (Maxim.) Kom.). Significant differences in both gene expression and metabolites accumulation were found between the two genotypes.

  13. Sugar from Palms

    DEFF Research Database (Denmark)

    Barfod, Anders

    Throughout the tropics and subtropics a large number of products are derived from the sugar-rich sap tapped from palms. I will give an overview of the most important species being exploited, harvesting practices and yields. I will further provide insights in the biomechanmics of sugar...... transportation in palms, which remain an enigma. Finally, the prospects for developing palm sugar into a commodity of worlswide significance will be discussed....

  14. Transport of sugars.

    Science.gov (United States)

    Chen, Li-Qing; Cheung, Lily S; Feng, Liang; Tanner, Widmar; Frommer, Wolf B

    2015-01-01

    Soluble sugars serve five main purposes in multicellular organisms: as sources of carbon skeletons, osmolytes, signals, and transient energy storage and as transport molecules. Most sugars are derived from photosynthetic organisms, particularly plants. In multicellular organisms, some cells specialize in providing sugars to other cells (e.g., intestinal and liver cells in animals, photosynthetic cells in plants), whereas others depend completely on an external supply (e.g., brain cells, roots and seeds). This cellular exchange of sugars requires transport proteins to mediate uptake or release from cells or subcellular compartments. Thus, not surprisingly, sugar transport is critical for plants, animals, and humans. At present, three classes of eukaryotic sugar transporters have been characterized, namely the glucose transporters (GLUTs), sodium-glucose symporters (SGLTs), and SWEETs. This review presents the history and state of the art of sugar transporter research, covering genetics, biochemistry, and physiology-from their identification and characterization to their structure, function, and physiology. In humans, understanding sugar transport has therapeutic importance (e.g., addressing diabetes or limiting access of cancer cells to sugars), and in plants, these transporters are critical for crop yield and pathogen susceptibility.

  15. Flavonoides de Lonchocarpus campestris (Leguminosae

    Directory of Open Access Journals (Sweden)

    Andreza Maria L. Pires

    2011-01-01

    Full Text Available A new flavone named 3,4',5,6-tetramethoxy-[2'',3'':7,8]furanoflavone besides the known flavonoids (2S,3R,4S-3,4,5,8-tetramethoxy-[2'',3'':6,7]-furanoflavan, 3,6-dimethoxy-2'',2''-dimethylcromene-[2'',3'':7,8] -flavone, 3,5,6-trimethoxy-[2'',3'':7,8]-furanoflavone, 2,4',4,5-tetramethoxy-[2'',3'':6,7]-furanodihydroaurone, (2R,3S,4S-3,4,5,6-tetramethoxy-[2'',3'':7,8]-furanoflavan and 3',4'-methylenodioxy-5,6-dimethoxy-[2'',3'':7,8]-furanoflavone were isolated from the root barks of Lonchocarpus campestris. The complete ¹H and 13C NMR assignments of the new furan flavonoid was performed using 1D and 2D pulse sequences, including COSY, HMQC and HMBC experiments.

  16. Regulation of NF-{kappa}B activity in astrocytes: effects of flavonoids at dietary-relevant concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Spilsbury, Alison [Reading School of Pharmacy, University of Reading, Reading RG6 6UB (United Kingdom); Vauzour, David; Spencer, Jeremy P.E. [Molecular Nutrition Group, Centre for Integrative Neuroscience and Neurodynamics, School of Chemistry, Food and Pharmacy, University of Reading, Reading RG6 6AP (United Kingdom); Rattray, Marcus, E-mail: m.a.n.rattray@reading.ac.uk [Reading School of Pharmacy, University of Reading, Reading RG6 6UB (United Kingdom)

    2012-02-17

    Highlights: Black-Right-Pointing-Pointer We tested the hypothesis that low concentrations of flavonoids inhibit NF-{kappa}B in astrocytes. Black-Right-Pointing-Pointer Primary cultured astrocytes possess a functional {kappa}B-system, measured using luciferase assays. Black-Right-Pointing-Pointer Seven flavonoids (100 nM-1 {mu}M) failed to reduce NF-{kappa}B activity in astrocytes. Black-Right-Pointing-Pointer Four flavonoids (100 nM-1 {mu}M) failed to reduce TNFa-stimulated NF-{kappa}B activity in astrocytes. Black-Right-Pointing-Pointer (-)-Epicatechin did not regulate nuclear translocation of the NF-{kappa}B subunit, p65. -- Abstract: Neuroinflammation plays an important role in the progression of neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Sustained activation of nuclear transcription factor {kappa}B (NF-{kappa}B) is thought to play an important role in the pathogenesis of neurodegenerative disorders. Flavonoids have been shown to possess antioxidant and anti-inflammatory properties and we investigated whether flavonoids, at submicromolar concentrations relevant to their bioavailability from the diet, were able to modulate NF-{kappa}B signalling in astrocytes. Using luciferase reporter assays, we found that tumour necrosis factor (TNF{alpha}, 150 ng/ml) increased NF-{kappa}B-mediated transcription in primary cultures of mouse cortical astrocytes, which was abolished on co-transfection of a dominant-negative I{kappa}B{alpha} construct. In addition, TNF{alpha} increased nuclear localisation of p65 as shown by immunocytochemistry. To investigate potential flavonoid modulation of NF-{kappa}B activity, astrocytes were treated with flavonoids from different classes; flavan-3-ols ((-)-epicatechin and (+)-catechin), flavones (luteolin and chrysin), a flavonol (kaempferol) or the flavanones (naringenin and hesperetin) at dietary-relevant concentrations (0.1-1 {mu}M) for 18 h. None of the flavonoids modulated constitutive or

  17. Extraction of catechins and caffeine from different tealeaves and comparison with micellar electrokinetic chromatography

    Institute of Scientific and Technical Information of China (English)

    SONG Guanqun; LIN Jinming; Qu Feng; C.W.Huie

    2003-01-01

    This work describes the simultaneous deter- mination of catechins and caffeine in green, black tealeaves and canned tea-drink using micellar electrokinetic chromatography. The catechins analyzed include (+)-catechin, (-)- epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. Using UV absorption method at 280 nm, the limits of detections of catechins and caffeine are 10-6 mol/L, which is suitable for the real sample determination. Using this analytical method, the extraction of these compounds from the tealeaves with hot water is compared under different temperatures. The effects of temperature on the amount of catechins and caffeine extracted are evident, showing that (-)-epigallocatechin gallate is the most easiest to be extracted at 100℃. The stability of catechins and caffeine in stocking solution of tea-drink at 4℃ is also compared on five consecutive days. The contents of catechins and caffeine in green and black teas are discussed and the difference of the content between different tealeaves can provide a reference for the assessment of tea quality.

  18. The galloyl catechins contributing to main antioxidant capacity of tea made from Camellia sinensis in China.

    Science.gov (United States)

    Zhao, Chunjian; Li, Chunying; Liu, Shuaihua; Yang, Lei

    2014-01-01

    Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82-32.36%. Total catechins content was in the range of 4.34-24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC) test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging test. Total polyphenol content, catechins content, and antioxidant capacity decreased in the following order: green > oolong > black > dark tea. A positive correlation existed between the antioxidant capacity and total polyphenol content or catechins content (R (2) = 0.67-0.87). The antioxidant capacities of five major catechins (epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epicatechin, epigallocatechin, and catechin) were determined by online HPLC DPPH radical-scavenging; the antioxidant activity of tea was mainly attributed to the esterified catechins (EGCG or ECG).

  19. The Galloyl Catechins Contributing to Main Antioxidant Capacity of Tea Made from Camellia sinensis in China

    Directory of Open Access Journals (Sweden)

    Chunjian Zhao

    2014-01-01

    Full Text Available Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82–32.36%. Total catechins content was in the range of 4.34–24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH radical-scavenging test. Total polyphenol content, catechins content, and antioxidant capacity decreased in the following order: green > oolong > black > dark tea. A positive correlation existed between the antioxidant capacity and total polyphenol content or catechins content (R2=0.67–0.87. The antioxidant capacities of five major catechins (epigallocatechin gallate (EGCG, epicatechin gallate (ECG, epicatechin, epigallocatechin, and catechin were determined by online HPLC DPPH radical-scavenging; the antioxidant activity of tea was mainly attributed to the esterified catechins (EGCG or ECG.

  20. Effects of catechins on vascular tone in rat thoracic aorta with endothelium.

    Science.gov (United States)

    Sanae, Fujiko; Miyaichi, Yukinori; Kizu, Haruhisa; Hayashi, Hisao

    2002-10-11

    The effects of eight catechin derivatives on vascular tone in rat thoracic aorta were examined. Catechin derivatives (10 microM) potentiated the contractile response to phenylephrine in endothelium-intact arteries. The potentiations produced by EGCg and EGC were almost absent in endothelium-denuded arteries and abolished by N(G)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthesis. The catechin derivatives also inhibited endothelium-dependent relaxation in response to acetylcholine. The order of catechin derivatives ranked in terms of both increasing vascular reactivity and impairing endothelium-dependent relaxation was similar; (-)-gallocatechin (GC) >or= (-)-epigallocatechin (EGC) >or= (-)-gallocatechin gallate (GCg) >or= (-)-epigallocatechin gallate (EGCg) >or= (-)-catechin (C) >or= (-)-epicatechin (EC) >or= (-)-catechin gallate (Cg) >or= (-)-epicatechin gallate (ECg). In addition, EGC inhibited the endothelium-independent relaxation evoked by both sodium nitroprusside and NOC-7, a spontanous NO releaser, but EGCg inhibited only that by NOC-7. These findings indicate that catechin derivatives produce a potentiation of the contractile response and an inhibition of the vasorelaxant response, probably through inactivation of endothelium-derived nitric oxide (NO), and that the hydroxyl on C-5 of the B ring together with the stereoscopic structure between the C-3 group and the B ring of flavanols was of importance in mediating the above effects and that the substitution of a gallate group of C-3 attenuated the effects, probably due to a decreased response to solube guanylate cyclase in vascular smooth muscle cells.

  1. Analysis of catechins in Theobroma cacao beans by cyclodextrin-modified micellar electrokinetic chromatography.

    Science.gov (United States)

    Gotti, Roberto; Furlanetto, Sandra; Pinzauti, Sergio; Cavrini, Vanni

    2006-04-21

    A micellar electrokinetic chromatography (MEKC) method was developed for the quantitation of polyphenols (+)-catechin and (-)-epicatechin (catechin monomers) and the methylxanthine theobromine in Theobroma cacao beans. Owing to the poor stability of catechin monomers in alkaline conditions, a 50 mM Britton-Robinson buffer at a pH 2.50 was preferred as the background electrolyte. Under these conditions, the addition of hydroxypropyl-beta-cyclodextrin (HP-beta-CD) at a concentration of 12 mM to the SDS micellar solution (90 mM), resulted in a cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) endowed with two peculiar advantages compare to the conventional MEKC: (i) strong improvement of separation of the most important phytomarkers of T. cacao and (ii) enantioselectivity toward (+/-)-catechin. In particular, separation of methylxanthines (theobromine and caffeine), procyanidin dimers B1 and B2, and catechins (epicatechin and catechin) was obtained simultaneously to the enantioseparation of racemic catechin within 10min. The enantioselectivity of the method makes it suitable in evaluation of possible epimerisation at the C-2 position of epicatechin monomer potentially occurring during heat processing and storage of T. cacao beans. The extraction procedure of the phytomarkers from the beans was approached using ultrasonic bath under mild conditions optimized by a multivariate strategy. The method was validated for robustness, selectivity, sensitivity, linearity, range, accuracy and precision and it was applied to T. cacao beans from different countries; interestingly, the native enantiomer (+)-catechin was found in the beans whereas, for the first time we reported that in chocolate, predominantly (-)-catechin is present, probably yielded by epimerisation of (-)-epicatechin occurred during the manufacture of chocolate.

  2. Tea catechins modulate the glucose transport system in 3T3-L1 adipocytes.

    Science.gov (United States)

    Ueda, Manabu; Furuyashiki, Takashi; Yamada, Kayo; Aoki, Yukiko; Sakane, Iwao; Fukuda, Itsuko; Yoshida, Ken-Ichi; Ashida, Hitoshi

    2010-11-01

    In this study, we investigated the effects of tea catechins on the translocation of glucose transporter (GLUT) 4 in 3T3-L1 adipocytes. We found that the ethyl acetate fraction of green tea extract, containing abundant catechins, most decreased insulin-induced glucose uptake activity in 3T3-L1 cells. When the cells were treated with 50 μM catechins in the absence or presence of insulin for 30 min, nongallate-type catechins increased glucose uptake activity without insulin, whereas gallate-type catechins decreased insulin-induced glucose uptake activity. (-)-Epicatechin (EC) and (-)-epigallocatechin (EGC), nongallate-type catechins, increased glucose uptake activity in the dose- and time-dependent manner, whereas (-)-catechin 3-gallate (Cg) and (-)-epigallocatechin 3-gallate (EGCg), gallate-type catechins, decreased insulin-induced glucose uptake activity in the dose- and time-dependent manner. When the cells were treated with 50 μM catechins for 30 min, EC and EGC promoted GLUT4 translocation, whereas Cg and EGCg decreased the insulin-induced translocation in the cells. EC and EGC increased phosphorylation of PKCλ/ζ without phosphorylation of insulin receptor (IR) and Akt. Wortmannin and LY294002, inhibitors for phosphatidylinositol 3'-kinase (PI3K), decreased EC- and EGC-induced glucose uptake activity in the cells. Cg and EGCg decreased phosphorylation of PKCλ/ζ in the presence of insulin without affecting insulin-induced phosphorylation of IR, and Akt. Therefore, EC and EGC promote the translocation of GLUT4 through activation of PI3K, and Cg and EGCg inhibit insulin-induced translocation of GLUT4 by the insulin signaling pathway in 3T3-L1 cells.

  3. Hyperactivity and sugar

    Science.gov (United States)

    ... likely to be hyperactive if they eat sugar, artificial sweeteners, or certain food colorings. Other experts disagree with this. Side Effects Some people claim that eating sugar (such as sucrose), aspartame (NutraSweet), and artificial flavors and colors lead to hyperactivity and other ...

  4. Drug-delivery systems of green tea catechins for improved stability and bioavailability.

    Science.gov (United States)

    Rodrigues, C F; Ascenção, K; Silva, F A M; Sarmento, B; Oliveira, M B P P; Andrade, J C

    2013-01-01

    Numerous studies in humans, animal models and cell lines have suggested the potential benefits from the consumption of green tea polyphenols, including prevention of cancer and heart diseases. However these potential effects have been strongly limited by green tea catechins low bioavailability, which hinders the development of therapeutic applications. In this review formulations that are being proposed for delivery of green tea catechins are discussed. New delivery systems are presented as valid alternatives to overcome the limitations such as green tea catechins poor stability or intestinal absorption.

  5. Sugar (sucrose) holograms

    Science.gov (United States)

    Ponce-Lee, E. L.; Olivares-Pérez, A.; Fuentes-Tapia, I.

    2004-06-01

    Computer holograms made with sugar crystals are reported. This material is well known as a good sweetener; the sugar from sugar cane or sugar beet (sucrose). These sweetener can be applied as honey "water and diluted sugar" easily on any substrate such as plastics or glasses without critical conditions for developed process. This step corresponds only to the cured sucrose as a photopolymer process. The maximum absorption spectra is localized at UV region λ=240 nm. We record with lithographic techniques some gratings, showing a good diffraction efficiency around 45%. This material has good resolution to make diffraction gratings. These properties are attractive because they open the possibility to make phase holograms on candies. Mainly the phase modulation is by refraction index.

  6. Quantitative and Qualitative Analysis of Phenolic and Flavonoid Content in Moringa oleifera Lam and Ocimum tenuiflorum L.

    Science.gov (United States)

    Sankhalkar, Sangeeta; Vernekar, Vrunda

    2016-01-01

    Number of secondary compounds is produced by plants as natural antioxidants. Moringa oleifera Lam. and Ocimum tenuiflorum L. are known for their wide applications in food and pharmaceutical industry. To compare phenolic and flavonoid content in M. oleifera Lam and O. tenuiflorum L. by quantitative and qualitative analysis. Phenolic and flavonoid content were studied spectrophotometrically and by paper chromatography in M. oleifera Lam. and O. tenuiflorum L. Higher phenolic and flavonoid content were observed in Moringa leaf and flower. Ocimum flower showed higher phenolic content and low flavonoid in comparison to Moringa. Flavonoids such as biflavonyl, flavones, glycosylflavones, and kaempferol were identified by paper chromatography. Phytochemical analysis for flavonoid, tannins, saponins, alkaloids, reducing sugars, and anthraquinones were tested positive for Moringa and Ocimum leaf as well as flower. In the present study higher phenolic and flavonoid content, indicated the natural antioxidant nature of Moringa and Ocimum signifying their medicinal importance. Moringa oleifera Lam. and Ocimum tenuiflorum L. are widly grown in India and are known for their medicinal properties. Number of secondary metabolites like phenolics and flavonoids are known to be present in both the plants. The present study was conducted with an objective to qualitatively and quantitatively compare the phenolics and flavanoids in these two medicinally important plants.Quantitation of total phenolics and flavanoids was done by spectrophotometrically while qualitative analysis was perfomed by paper chromatography and by phytochemical tests. Our results have shown higher phenolics and flavanoid content in Moringa leaf and flower. However, higher phenolic content was absent in Ocimum flower compared to that of Moringa. Phytochemical analysis of various metabolites such as flavonoids, tanins, sapponins, alkaloids, anthraquinones revealed that both the plant extracts were rich sources of

  7. Identification and concentration of some flavonoid components in Malaysian young ginger (Zingiber officinale Roscoe) varieties by a high performance liquid chromatography method.

    Science.gov (United States)

    Ghasemzadeh, Ali; Jaafar, Hawa Z E; Rahmat, Asmah

    2010-09-03

    Flavonoids make up one of the most pervasive groups of plant phenolics. Due to their importance in plants and human health, it would be useful to have a better understanding of flavonoid concentration and biological activities that could indicate their potentials as therapeutic agents, and also for predicting and controlling the quality of medicinal herbs. Ginger (Zingiber officinale Roscoe) is a famous and widely used herb, especially in Asia, that contains several interesting bioactive constituents and possesses health promoting properties. In this study, total flavonoids and some flavonoid components including quercetin, rutin, catechin, epicatechin, kaempferol and naringenin were extracted from the leaves and rhizomes of two varieties of Zingiber officinale (Halia Bentong and Halia Bara) at three different growth points (8, 12 and 16 weeks after planting), and analyzed by a high performance liquid chromatography (HPLC) method in order to determine the potential of the subterranean part of the young ginger. The results showed that Halia Bara had a higher content of flavonoids in the leaves and rhizomes as compared to Halia Bentong. In both varieties, the concentration of flavonoids in the leaves decreased (Halia Bentong, 42.3%; Halia Bara 36.7%), and in the rhizomes it increased (Halia Bentong 59.6%; Halia Bara 60.1%) as the growth period increased. Quercetin was abundant in both varieties. The antioxidant activity determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay showed high activities (65.7%) in the leaves of Halia Bara at 8 weeks after planting. Results suggested a good flavonoid content and antioxidant activity potential in ginger leaves at 8 weeks after planting. The leaves of these ginger varieties could be useful for both food flavourings and in traditional medicine.

  8. Identification and Concentration of Some Flavonoid Components in Malaysian Young Ginger (Zingiber officinale Roscoe Varieties by a High Performance Liquid Chromatography Method

    Directory of Open Access Journals (Sweden)

    Asmah Rahmat

    2010-09-01

    Full Text Available Flavonoids make up one of the most pervasive groups of plant phenolics. Due to their importance in plants and human health, it would be useful to have a better understanding of flavonoid concentration and biological activities that could indicate their potentials as therapeutic agents, and also for predicting and controlling the quality of medicinal herbs. Ginger (Zingiber officinale Roscoe is a famous and widely used herb, especially in Asia, that contains several interesting bioactive constituents and possesses health promoting properties. In this study, total flavonoids and some flavonoid components including quercetin, rutin, catechin, epicatechin, kaempferol and naringenin were extracted from the leaves and rhizomes of two varieties of Zingiber officinale (Halia Bentong and Halia Bara at three different growth points (8, 12 and 16 weeks after planting, and analyzed by a high performance liquid chromatography (HPLC method in order to determine the potential of the subterranean part of the young ginger. The results showed that Halia Bara had a higher content of flavonoids in the leaves and rhizomes as compared to Halia Bentong. In both varieties, the concentration of flavonoids in the leaves decreased (Halia Bentong, 42.3%; Halia Bara 36.7%, and in the rhizomes it increased (Halia Bentong 59.6%; Halia Bara 60.1% as the growth period increased. Quercetin was abundant in both varieties. The antioxidant activity determined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH assay showed high activities (65.7% in the leaves of Halia Bara at 8 weeks after planting. Results suggested a good flavonoid content and antioxidant activity potential in ginger leaves at 8 weeks after planting. The leaves of these ginger varieties could be useful for both food flavourings and in traditional medicine.

  9. Catechins inhibit atherosclerosis in male rats on a high fat diet

    Directory of Open Access Journals (Sweden)

    Erna Susanti

    2015-12-01

    High fat diet increases eNOS expression, decreases PI3K expression, and increases p38 MAPK activity. Administration of catechin decreases eNOS expression, increases PI3K expression, and decreases p38 MAPK activity.

  10. Catechin derivatives from Parapiptadenia rigida with in vitro wound-healing properties.

    Science.gov (United States)

    Schmidt, Cleber A; Murillo, Renato; Bruhn, Torsten; Bringmann, Gerhard; Goettert, Marcia; Heinzmann, Berta; Brecht, Volker; Laufer, Stefan A; Merfort, Irmgard

    2010-12-27

    Analysis of the ethanolic extract of the bark from Parapiptadenia rigida resulted in the isolation of the new catechin derivatives 4',3''-di-O-methylapocynin-D (10), 4',3''-di-O-methylapocynin-B (11), epigallocatechin-3-O-ferulate (8), and 4'-O-methylepigallocatechin-3-O-ferulate (9) and the catechins 4'-O-methylepigallocatechin-3-O-gallate (6) and 4'-O-methylepicatechin-3-O-gallate (7). These compounds, isolated for the first time from a natural source, are accompanied by the five known catechins 4'-O-methylgallocatechin (1), 4'-O-methylepigallocatechin (2), 3'-O-methylepicatechin (3), epigallocatechin-3-O-gallate (4), and epicatechin-3-O-gallate (5). Compounds 5 and 7 displayed promising wound-healing effects in a scratch assay. Some of the catechin derivatives showed inhibitory effects on NF-κB DNA binding and p38α MAPK activity.

  11. Determination of catechins in matcha green tea by micellar electrokinetic chromatography.

    Science.gov (United States)

    Weiss, David J; Anderton, Christopher R

    2003-09-05

    Catechins in green tea are known to have many beneficial health properties. Recently, it has been suggested that matcha has greater potential health benefits than other green teas. Matcha is a special powdered green tea used in the Japanese tea ceremony. However, there has been no investigation to quantitate the catechin intake from matcha compared to common green teas. We have developed a rapid method of analysis of five catechins and caffeine in matcha using micellar electrokinetic chromatography. Results are presented for water and methanol extractions of matcha compared with water extraction of a popular green tea. Using a mg catechin/g of dry leaf comparison, results indicate that the concentration of epigallocatechin gallate (EGCG) available from drinking matcha is 137 times greater than the amount of EGCG available from China Green Tips green tea, and at least three times higher than the largest literature value for other green teas.

  12. Acyl flavonoids, biflavones, and flavonoids from Cephalotaxus harringtonia var. nana.

    Science.gov (United States)

    Komoto, Noriko; Nakane, Takahisa; Matsumoto, Sachiko; Hashimoto, Shusuke; Shirota, Osamu; Sekita, Setsuko; Kuroyanagi, Masanori

    2015-10-01

    A methanol extract of the leaves of Cephalotaxus harringtonia var. nana and its ethyl acetate (EtOAc)-soluble fraction demonstrated strong antitumor activity against A549 and HT-29 cell lines. The EtOAc-soluble fraction was purified by column chromatography and high-performance liquid chromatography (HPLC) using a reverse-phase column to yield three novel acyl flavonoids and a biflavonoid, along with 15 other known compounds that included flavonoids, biflavonoids, and other phenolics. The structures of the new compounds were elucidated using spectral data from HR-MS and NMR, including two-dimensional NMR studies, as (2R,3R)-3-O-eicosanoyltaxifolin (1), (2R,3R)-3-O-docosanoyltaxifolin (2), (2R,3R)-3-O-tetracosanoyltaxifolin (3), and 6-methyl-4',7,7″-tri-O-methylamentoflavone (4). The isolated compounds, including the known compounds, were tested for possible antitumor activity; some of the biflavones were found to be active. The potent antitumor activity of the extract was attributed to Cephalotaxus alkaloids, such as homoharringtonine (20).

  13. Flavonoids from Lonchocarpus campestris (Leguminosae); Flavonoides de Lonchocarpus campestris (Leguminosae)

    Energy Technology Data Exchange (ETDEWEB)

    Pires, Andreza Maria L.; Silveira, Edilberto R.; Pessoa, Otilia Deusdenia L., E-mail: opessoa@ufc.b [Universidade Federal do Ceara (DQOI/UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica

    2011-07-01

    A new flavone named 3,4',5,6-tetramethoxy-[2'', 3'':7,8] furanoflavone besides the known flavonoids (2S,3R,4S)-3,4,5,8-tetramethoxy-[2'',3'':6,7]-furanoflavan, 3,6-dimethoxy-2'',2''-dimethylcromene-[2'',3'':7,8]-flavone, 3,5,6-trimethoxy-[2'',3'':7,8]-furanoflavone, 2,4',4,5-tetramethoxy-[2'',3'':6,7]-furanodihydroaurone, (2R,3S,4S)-3,4,5,6-tetramethoxy-[2'',3'':7,8]-furanoflavan and 3',4'-methylenedioxy-5,6-dimethoxy-[2'',3'':7,8]-furanoflavone were isolated from the root barks of Lonchocarpus campestris. The complete {sup 1}H and {sup 13}C NMR assignments of the new furan flavonoid was performed using 1D and 2D pulse sequences, including COSY, HMQC and HMBC experiments. (author)

  14. Comparative Antioxidant Activity and Total Flavonoid Content of Persian Pomegranate (Punica granatum L.) Cultivars.

    Science.gov (United States)

    Shams Ardekani, Mohammad Reza; Hajimahmoodi, Mannan; Oveisi, Mohammad Reza; Sadeghi, Naficeh; Jannat, Behrooz; Ranjbar, Ali Mohammad; Gholam, Narges; Moridi, Tahereh

    2011-01-01

    Pomegranate (Punica granatum L.), Lythraceae, is mainly grown in Mediterranean region. It is one of the major cultivated productions of Iran, which have been used in folk medicine for many centuries. It has been proved that pomegranate has a high antioxidant activity and is effective in the prevention of atherosclerosis. This study compares the antioxidant activity, total phenolic and flavonoid contents of nine different pomegranate cultivars grown in Iran. Aqueous solutions of known Fe(+2) concentration, vitamin E, vitamin C, gallic acid and catechin were used for calibration. The results showed that Sour summer pulp cultivar had the most antioxidant effect with significant difference with the other cultivar (p < 0.05) which can be introduced as a potent source of natural antioxidants, and the peel of three cultivars (Sweet saveh malas, Sour summer and Black peel) as a suitable source for extraction and purification of phenolic and flavonoid compound. The antioxidant capacity of pomegranate peel extract is 10 times higher than the pulp extract.

  15. Sugar Coated Taro

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    Taro is smooth and sticky in texture and rich in fat,protein and sugar.According to Chinese traditional medicine, taro nourishes the spine and stomach and helps energy. Ingredients:500 grams taro (peeled and chopped into diamond-shaped cubes), 15 grams sugar. 250 grams vegetable oil. Method: 1. Heat oil in a wok and add taro cubes. Fry unti they turn golden brown. 2. Take out the taro with a sieve and pour the oil into a container for later use. Add sugar and one tablespoon oil.Stir continuously to prevent burning. When the

  16. Phytotoxic effects of (+/--catechin in vitro, in soil, and in the field.

    Directory of Open Access Journals (Sweden)

    Inderjit

    Full Text Available BACKGROUND: Exploring the residence time of allelochemicals released by plants into different soils, episodic exposure of plants to allelochemicals, and the effects of allelochemicals in the field has the potential to improve our understanding of interactions among plants. METHODOLOGY/PRINCIPAL FINDINGS: We conducted experiments in India and the USA to understand the dynamics of soil concentrations and phytotoxicity of (+/--catechin, an allelopathic compound exuded from the roots of Centaurea maculosa, to other plants in vitro and in soil. Experiments with single and pulsed applications into soil were conducted in the field. Experimental application of (+/--catechin to soils always resulted in concentrations that were far lower than the amounts added but within the range of reported natural soil concentrations. Pulses replenished (+/--catechin levels in soils, but consistently at concentrations much lower than were applied, and even pulsed concentrations declined rapidly. Different natural soils varied substantially in the retention of (+/--catechin after application but consistent rapid decreases in concentrations over time suggested that applied experimental concentrations may overestimate concentrations necessary for phytotoxicity by over an order of magnitude. (+/--Catechin was not phytotoxic to Bambusa arundinacea in natural Indian soil in a single pulse, but soil concentrations at the time of planting seeds were either undetectable or very low. However, a single dose of (+/--catechin suppressed the growth of bamboo in sand, in soil mixed with organic matter, and Koeleria macrantha in soils from Montana and Romania, and in field applications at 40 microg l(-1. Multiple pulses of (+/--catechin were inhibitory at very low concentrations in Indian soil. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that (+/--catechin is highly dynamic in natural soils, but is phytotoxic well below natural concentrations measured in some soils and applied

  17. Systemic Absorption of Catechins after Intraruminal or Intraduodenal Application of a Green Tea Extract in Cows

    OpenAIRE

    Silvia Wein; Birgit Beyer; Annika Gohlke; Ralf Blank; Metges, Cornelia C.; Siegfried Wolffram

    2016-01-01

    Green tea catechins have various potential health benefits in humans including anti-inflammatory, anti-oxidative and hepato-protective effects. If present in the circulation, they might have similar effects in ruminants, which are exposed to oxidative stress and fatty liver disease such as dairy cows during the periparturient phase. However, the bioavailability of a substance is a prerequisite for any post absorptive effect in vivo. This study aimed to investigate the appearance of catechins ...

  18. Flavonoids:emerging trends and potential health benefits%Flavonoids: emerging trends and potential health benefits

    Institute of Scientific and Technical Information of China (English)

    Raj K.Keservani; Anil K.Sharma

    2014-01-01

    Flavonoids are widely used in industry for the prevention of various diseases.In daily life we are directly in touch with flavonoids due to their presence in different beverages,fruits and vegetables.Flavonoids are mainly used as a coloring agent in plants,antioxidant and nutritional food for human.Flavonoids have explicit role in UV filtration,symbiotic nitrogen fixation and floral pigmentation.Flavonoids have potential for different biological activities like chelation of metals,decreasing platelets aggregation and cell signaling etc.

  19. Developmental, genetic and environmental factors affect the expression of flavonoid genes, enzymes and metabolites in strawberry fruits.

    Science.gov (United States)

    Carbone, Fabrizio; Preuss, Anja; De Vos, Ric C H; D'Amico, Eleonora; Perrotta, Gaetano; Bovy, Arnaud G; Martens, Stefan; Rosati, Carlo

    2009-08-01

    The influence of internal (genetic and developmental) and external (environmental) factors on levels of flavonoid gene transcripts, enzyme activity and metabolites was studied in fruit of six cultivated strawberry (Fragaria x ananassa Duch.) genotypes grown at two Italian locations. Gene expression and enzyme activity showed development- and genotype-associated patterns, revealing gene coordination. Analysis clarified the regulation mechanism of the hydroxylation status of the B-ring of the major flavonoid pools and pointed out examples of genotype-specific post-transcriptional regulation mechanisms and key steps of pathway regulation in strawberry fruits. Metabolite profiles were strongly affected by development and genotype. Flavan-3-ols, their proanthocyanidin (PA) derivatives and anthocyanins were the most abundant metabolites. Flavonol levels and PA-associated traits (epicatechin/catechin ratio and mean degree of polymerization) showed significant environmental effects. Multivariate and correlation analyses determined the relationships among genes, enzymes and metabolites. The combined molecular and biochemical information elucidated more in depth the role of genetic and environmental factors on flavonoid metabolism during strawberry fruit development, highlighting the major impact of developmental processes, and revealing genotype-dependent differences and environmental effects on PA-related traits.

  20. Total flavonoid content and antioxidant activity in leaves and stems extract of cultivated and wild tabat barito (Ficus deltoidea Jack)

    Science.gov (United States)

    Manurung, Hetty; Kustiawan, Wawan; Kusuma, Irawan W.; Marjenah

    2017-02-01

    Tabat barito (Ficus deltoidea Jack) is a name given by Dayak Tribe who lived in Borneo-Kalimantan and it is belongs to the moraceae. Almost all of the parts of F. deltoidea plant is widely used as a medicinal property. The total flavonoid content (TFC) and antioxidant activity from cultivated and wild F. deltoidea leaves and stems extract were assessed. Total flavonoid content was estimated by using Aluminium chloride colorimetric method and expressed as catechin equivalents (mg CE g-1 extract) and the antioxidant activity by the DPPH (2,2-diphenyl-1-picryl hydrazyl) method. The content of total flavonoid of leaves and stems (430.77 and 371.80 µg CE mg-1 extract) of cultivated F. deltoidea were higher than in the wild leaves and stems (114.82 and 66.67 µg CE mg-1 extract). The IC50 of leaves extract of cultivated and wild F. deltoidea, based on the DPPH assay, has a strong antioxidant activity (34.19 and 39.31 µg mL-1 extract) as compared to stems extract. These results showed that the cultivated F. deltoidea are suitable source for medicinal properties and the leaves could be exploited as source of natural antioxidants.

  1. Interaction of environmental moisture with powdered green tea formulations: effect on catechin chemical stability.

    Science.gov (United States)

    Ortiz, J; Ferruzzi, M G; Taylor, L S; Mauer, L J

    2008-06-11

    Green tea and tea catechins must be stable in finished products to deliver health benefits; however, they may be adversely affected by tea processing/storage conditions and the presence of other components. The objective of this study was to determine the effects of storage relative humidity (RH) and addition of other ingredients on catechin stability in simulated dry beverage mixtures. Samples of green tea powder alone and mixed with sucrose, citric acid, and/or ascorbic acid were prepared and stored in desiccators at 22 degrees C and 0-85% RH for up to 3 months. Epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate were determined by high-performance liquid chromatography (HPLC). Formulation and the interaction of formulation and RH significantly promoted catechin degradation ( P or = 58% RH by the presence of powdered citric acid and at > or = 75% RH by the presence of ascorbic acid. Catechins degraded the most in formulations containing both acids. Although catechin chemical stability was maintained at < or = 43% RH in all samples stored at 22 degrees C for 3 months, caking was observed in samples at these relative humidities. These results are the first to demonstrate that addition of other dry components to tea powders may affect catechin stability in finished dry blends and highlight the importance of considering the complex interplay between a multicomponent system and its environment for developing stable products.

  2. Inhibiting effect of tea catechins on the lipid peroxidation induced in tritiated water

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, M. [Radiochemical Research Laboratory, University of Shizuoka, 836 Ohya, Shizuoka-shi 422-8529 (Japan); Takeuchi, Y. [Radiochemical Research Laboratory, University of Shizuoka, 836 Ohya, Shizuoka-shi 422-8529 (Japan); Okuno, K. [Radiochemical Research Laboratory, University of Shizuoka, 836 Ohya, Shizuoka-shi 422-8529 (Japan); Yoshioka, H. [Institute for Environmental Sciences, University of Shizuoka, 52-1 Yada, Shizuoka-shi 422-8526 (Japan); Yoshioka, H. [Radiochemical Research Laboratory, University of Shizuoka, 836 Ohya, Shizuoka-shi 422-8529 (Japan)]. E-mail: srhyosi@ipc.shizuoka.ac.jp

    2006-02-15

    Lipid peroxidation induced by {beta}-ray in tritiated water and the inhibiting effect of tea catechins on it were studied using a spin probe method. A hydrophobic spin probe, 16-doxylstearic acid (16NS), was incorporated into a liposome prepared from egg yolk phosphatidylcholine, which was dispersed in tritiated water; the catechins were added to the solution. The rate of the decrease of ESR intensity of 16NS was a measure of the peroxidation and of the inhibiting effect. Inhibiting activity increased with an increase in the concentration of the catechin. Inhibiting ability estimated from the slope of the curves was in the order of (-)-epicatechin gallate > (-)-epigallocatechin gallate > (-)-epicatechin > (-)-epigallocatechin. The activity decreased with increasing temperature and the temperature dependence increased with the catechin concentration. These results were explained by a model; the initiator of the peroxidation is the hydroxyl radical (OH) and catechin is adsorbed on the surface of the membrane and scavenges OH coming into there from the water phase. The activity depended on the ratio of the adsorbed catechin, namely the partition coefficient between the water and the lipid.

  3. Estimation of tea catechin levels using micellar electrokinetic chromatography: a quantitative approach.

    Science.gov (United States)

    Liu, Chao-Ming; Chen, Chung-Yu; Lin, Yang-Wei

    2014-05-01

    A simple, inexpensive micellar electrokinetic chromatography (MEKC) method with UV detection was used to determine seven catechins and one xanthine (caffeine) in tea. All the compounds were successfully separated (15kV) within a 15-min migration period with a high number of theoretical plates (>8.0×10(4)) in a running buffer (pH 7) containing 10mmoll(-1) sodium tetraborate, 4mmoll(-1) sodium phosphate, and 25mmoll(-1) SDS. The regression lines of all standard catechins were linear within the range of 0.03-4μgml(-1). Green tea infused at 95°C for 10min showed higher levels of catechins (especially epigallocatechin galate, epicatechin gallate, and epicatechin) than tea infused at 80°C. In addition, major differences were observed in the levels of catechins in the first and second infusions (both brewed at 95°C for 10min). Finally, green tea leaves were infused separately with tap water, deionised water, spring water, reverse osmosis water, and distilled water at 95°C, and the catechin content of the infusions was investigated by the proposed method. In the infusion brewed with tap water, catechins appeared to be epimerisation from the epistructure to the nonepistructure. This epimerisation may take place more readily in tap water than in distilled water owing to the complexity of the ions present in tap water.

  4. Factors Influencing the Antifolate Activity of Synthetic Tea-Derived Catechins

    Directory of Open Access Journals (Sweden)

    José Neptuno Rodríguez-López

    2013-07-01

    Full Text Available Novel tea catechin derivatives have been synthesized, and a structure-activity study, related to the capacity of these and other polyphenols to bind dihydrofolate reductase (DHFR, has been performed. The data showed an effective binding between all molecules and the free enzyme, and the dissociation constants of the synthetic compounds and of the natural analogues were on the same order. Polyphenols with a catechin configuration were better DHFR inhibitors than those with an epicatechin configuration. Antiproliferative activity was also studied in cultured tumour cells, and the data showed that the activity of the novel derivatives was higher in catechin isomers. Derivatives with a hydroxyl group para on the ester-bonded gallate moiety presented a high in vitro binding to DHFR, but exhibited transport problems in cell culture due to ionization at physiologic pHs. The impact of the binding of catechins to serum albumin on their biological activity was also evaluated. The information provided in this study could be important for the design of novel medicinal active compounds derived from tea catechins. The data suggest that changes in their structure to avoid serum albumin interactions and to facilitate plasmatic membrane transport are essential for the intracellular functions of catechins.

  5. Optimizing conditions for the extraction of catechins from green tea using hot water.

    Science.gov (United States)

    Vuong, Quan V; Golding, John B; Stathopoulos, Costas E; Nguyen, Minh H; Roach, Paul D

    2011-11-01

    Six different factors involved in the extraction of catechins from green tea using water were examined for their impact on the yield of catechins and on the efficiency of water use. The best temperature and time combination for catechin extraction was at 80°C for 30 min. The yield of catechins was also optimal with a tea particle size of 1 mm, a brewing solution pH tea-to-water ratio at 50:1 (mL/g). In terms of efficient use of water in a single extraction, a water-to-tea ratio of 20:1 (mL/g) gave the best results; 2.5 times less water was used per gram of green tea. At the water-to-tea ratio of 20:1 mL/g, the highest yield of catechins per gram of green tea was achieved by extracting the same sample of green tea twice. However, for the most efficient use of water, the best extraction was found to be once at a water-to-tea ratio of 12:1 (mL/g) and once at a water-to-tea ratio of 8:1 (mL/g). Therefore, all six of the factors investigated had an impact on the yield of catechins extracted from green tea using water and two had an impact on the efficiency of water use.

  6. Factors influencing the antifolate activity of synthetic tea-derived catechins.

    Science.gov (United States)

    Sáez-Ayala, Magalí; Fernández-Pérez, María Piedad; Chazarra, Soledad; Mchedlishvili, Nani; Tárraga-Tomás, Alberto; Rodríguez-López, José Neptuno

    2013-07-16

    Novel tea catechin derivatives have been synthesized, and a structure-activity study, related to the capacity of these and other polyphenols to bind dihydrofolate reductase (DHFR), has been performed. The data showed an effective binding between all molecules and the free enzyme, and the dissociation constants of the synthetic compounds and of the natural analogues were on the same order. Polyphenols with a catechin configuration were better DHFR inhibitors than those with an epicatechin configuration. Antiproliferative activity was also studied in cultured tumour cells, and the data showed that the activity of the novel derivatives was higher in catechin isomers. Derivatives with a hydroxyl group para on the ester-bonded gallate moiety presented a high in vitro binding to DHFR, but exhibited transport problems in cell culture due to ionization at physiologic pHs. The impact of the binding of catechins to serum albumin on their biological activity was also evaluated. The information provided in this study could be important for the design of novel medicinal active compounds derived from tea catechins. The data suggest that changes in their structure to avoid serum albumin interactions and to facilitate plasmatic membrane transport are essential for the intracellular functions of catechins.

  7. Degradation kinetics of catechins in green tea powder: effects of temperature and relative humidity.

    Science.gov (United States)

    Li, Na; Taylor, Lynne S; Mauer, Lisa J

    2011-06-08

    The stability of catechins in green tea powders is important for product shelf life and delivering health benefits. Most published kinetic studies of catechin degradation have been conducted with dilute solutions and, therefore, are limited in applicability to powder systems. In this study, spray-dried green tea extract powders were stored under various relative humidity (RH) (43-97%) and temperature (25-60 °C) conditions for up to 16 weeks. High-performance liquid chromatography (HPLC) was used to determine catechin contents. Catechin degradation kinetics were affected by RH and temperature, but temperature was the dominant factor. Kinetic models as functions of RH and temperature for the individual 2,3-cis-configured catechins (EGCG, EGC, ECG, and EC) were established. The reaction rate constants of catechin degradation also followed the Williams-Landel-Ferry (WLF) relationship. This study provides a powerful prediction approach for the shelf life of green tea powder and highlights the importance of glass transition in solid state kinetics studies.

  8. Green tea catechins and their oxidative protection in the rat eye.

    Science.gov (United States)

    Chu, Kai On; Chan, Kwok Ping; Wang, Chi Chiu; Chu, Ching Yan; Li, Wai Ying; Choy, Kwong Wai; Rogers, Michael Scott; Pang, Chi Pui

    2010-02-10

    Catechins, active constituents of green tea, are well-known antioxidative natural products. It was proposed that green tea extract (GTE) consumption could benefit the eye, and the pharmacokinetics of catechins and oxidation status in rat eye were investigated after oral administration. Sprague-Dawley rats were fed GTE and sacrificed at different time intervals. Their eyes were dissected into cornea, lens, retina, choroid-sclera, vitreous humor, and aqueous humor for analysis of catechins and 8-epi-isoprostane by HPLC-ECD and GC-NCI-MS, respectively. Catechins were differentially distributed in eye tissues. Gallocatechin was present at the highest concentration in the retina, 22729.4 +/- 4229.4 pmol/g, and epigallocatechin in aqueous humor at 602.9 +/- 116.7 nM. The corresponding area-under-curves were 207,000 pmol x h/g and 2035.0 +/- 531.7 nM x h, respectively. The time of maximum concentration of the catechins varied from 0.5 to 12.2 h. Significant reductions in 8-epi-isoprostane levels were found in the compartments except the choroid-sclera or plasma, indicating antioxidative activities of catechins in these tissues.

  9. Effects of different brewing conditions on catechin content and sensory acceptance in Turkish green tea infusions.

    Science.gov (United States)

    Saklar, Sena; Ertas, Erdal; Ozdemir, Ibrahim S; Karadeniz, Bulent

    2015-10-01

    The optimal brewing conditions for Turkish green tea were determined on the basis of extracted catechins and sensory attributes. Green tea infusions were prepared at 75, 85 and 95 °C with brewing times of 1, 2, 3, 5, 10, 20, 30 and 45 min. The amounts of epistructured catechins (EGCG, EGC, ECG, EC), non-epistructured catechins (C, GC, GCG) and caffeine in brewed tea samples were analysed. Sensory analyses were performed by nine trained panelists for infusion colour, taste, aroma and overall acceptability. Brewing at 85 °C for 3 min was found to be the optimal condition, where the EGCG content was at a maximum of 50.69 mg/100 ml with the highest sensory scores. It was observed that the yield of epistructured catechins increased rapidly for the first 3-5 min of brewing at 85 °C, and increased brewing time resulted in a decrease in the yield of epistructured catechins. The amount of nonepistructured catechins continued to increase with longer extraction times. Sensory scores for infusion colour, taste, aroma and overall acceptability were highest at 3 and 5 min brewing times at all temperatures. Sensory scores were very low for 30 and 45 min brewing at 85 and 95 °C due to the bitter taste and dark colour.

  10. Dietary flavonoids: intake, health effects and bioavailability

    NARCIS (Netherlands)

    Hollman, P.C.H.; Katan, M.B.

    1999-01-01

    Flavonoids are polyphenolic compounds that occur ubiquitously in foods of plant origin. Over 4000 different flavonoids have been described. They may have beneficial health effects because of their antioxidant properties and their inhibitory role in various stages of tumour development in animal stud

  11. Rare prenylated flavonoids from Tephrosia purpurea.

    Science.gov (United States)

    Hegazy, Mohamed-Elamir F; Abd el-Razek, Mohamed H; Nagashima, Fumihiro; Asakawa, Yoshinori; Paré, Paul W

    2009-01-01

    Chemical investigations of aerial parts of Tephrosia purpurea yielded the rare prenylated flavonoids, tephropurpulin A (1) and isoglabratephrin (2), in addition to a previously identified flavonoid, glabratephrin (3). Structures were established by 1D and 2D NMR spectroscopy, as well as by HR-MS analysis; for compounds 2 and 3, structures were confirmed by X-ray analysis.

  12. Flavonoid variation in Eurasian Sedum and Sempervivum

    NARCIS (Netherlands)

    Stevens, J.F; 't Hart, H; Elema, E.T; Bolck, A

    1996-01-01

    Flavonoids from vegetative parts of 29 species of Eurasian Sedum, Sedum meyeri-johannis from central East Africa, 34 species of Sempervivum, and Jovibarba heuffelii have been identified after acid hydrolysis. Ten flavonoid aglycones were detected, i.e. kaempferol, herbacetin, sexangularetin, quercet

  13. Blood sugar test - blood

    Science.gov (United States)

    ... blood glucose level ( hypoglycemia ) may be due to: Hypopituitarism (a pituitary gland disorder) Underactive thyroid gland or ... tonic-clonic seizure Glucagon blood test Glucagonoma Hyperthyroidism Hypopituitarism Hypothyroidism Insulinoma Low blood sugar Multiple endocrine neoplasia ( ...

  14. Flavonoids and dementia: an update.

    Science.gov (United States)

    Orhan, I E; Daglia, M; Nabavi, S F; Loizzo, M R; Sobarzo-Sánchez, E; Nabavi, S M

    2015-01-01

    Dementia is a strongly age-related syndrome due to cognitive decline that can be considered a typical example of the combination of physiological and pathological aging-associated changes occurring in old people; it ranges from intact cognition to mild cognitive impairment, which is an intermediate stage of cognitive deterioration, and dementia. The spread of this syndrome has induced to study and try to reduce dementia modifiable risk factors. They include insulin resistance and hyperinsulinaemia, high blood pressure, obesity, smoking, depression, cognitive inactivity or low educational attainment as well as physical inactivity and incorrect diet, which can be considered one of the most important factors. One emerging strategy to decrease the prevalence of mild cognitive impairment and dementia may be the use of nutritional interventions. In the last decade, prospective data have suggested that high fruit and vegetable intakes are related to improved cognitive functions and reduced risks of developing a neurodegenerative process. The protective effects against neurodegeneration could be in part due to the intake of flavonoids that have been associated with several health benefits such as antioxidant and anti-inflammatory activities, increased neuronal signaling, and improved metabolic functions. The present article is aimed at reviewing scientific studies that show the protective effects of flavonoid intake against mild cognitive impairment and dementia.

  15. Flavonoids--food sources and health benefits.

    Science.gov (United States)

    Kozłowska, Aleksandra; Szostak-Wegierek, Dorota

    2014-01-01

    Flavonoids are a group of bioactive compounds that are extensively found in foodstuffs of plant origin. Their regular consumption is associated with reduced risk of a number of chronic diseases, including cancer, cardiovascular disease (CVD) and neurodegenerative disorders. Flavonoids are classified into subgroups based on their chemical structure: flavanones, flavones, flavonols, flavan-3-ols, anthocyanins and isoflavones. Their actions at the molecular level include antioxidant effects, as well the ability to modulate several key enzymatic pathways. The growing body of scientific evidence indicates that flavonoids play a beneficial role in disease prevention, however further clinical and epidemiological trials are greatly needed. Among dietary sources of flavonoids there are fruits, vegetables, nuts, seeds and spices. Consumption of these substances with diet appears to be safe. It seems that a diet rich in flavonoids is beneficial and its promotion is thus justifiable.

  16. Flavonoids as chemotaxonomic markers for Erythroxylum australe.

    Science.gov (United States)

    Johnson, Emanuel L; Schmidt, Walter F

    2004-01-01

    Methanolic leaf extracts of Erythroxylum australe F. Muell. produced eight O-conjugated flavonoids. Six of the flavonoid aglycones were dihydroisoflavones (all dihydro-orobol derivatives), one a flavanone, eriodictyol, and one a flavonol, quercetin. The major glycosides of the flavonoids included mono-glucosyl-rhamnosyls and dirhamnosyl-glucosides with either 3, 5, 7 or 3', 4' linkage or a combination thereof The array of flavonoids present in E. australe suggests kinship to E. ulei and linkage to the four cultivated alkaloid-bearing Erythroxylum, especially the ancestral E. coca var. coca. Because of the uniqueness of the flavonoids present in leaf tissue of E. australe they are unambiguously useful as chemotaxonomic markers for the taxon.

  17. Optimizing Polychlorinated Biphenyl Degradation by Flavonoid-Induced Cells of the Rhizobacterium Rhodococcus erythropolis U23A.

    Directory of Open Access Journals (Sweden)

    Thi Thanh My Pham

    Full Text Available There is evidence that many plant secondary metabolites may act as signal molecules to trigger the bacterial ability to metabolize polychlorinated biphenyls (PCBs during the rhizoremediation process. However, the bases for the PCB rhizoremediation process are still largely unknown. The rhizobacterium Rhodococcus erythropolis U23A is unable to use flavanone as a growth substrate. However, on the basis of an assay that monitors the amount of 4-chlorobenzoate produced from 4-chlorobiphenyl by cells grown co-metabolically on flavanone plus sodium acetate, this flavonoid was previously found to be a potential inducer of the U23A biphenyl catabolic pathway. In this work, and using the same assay, we identified ten other flavonoids that did not support growth, but that acted as inducers of the U23A biphenyl pathway, and we confirmed flavonoid induction of the biphenyl catabolic pathway using quantitative real-time polymerase chain reaction (RT-qPCR on the bphA gene. We also examined the effect of the growth co-substrate on flavonoid induction. Sodium acetate was replaced by glucose, mannose, sucrose, or mannitol, which are sugars found in plant root exudates. The data showed that the level of induction of strain U23A biphenyl-degrading enzymes was significantly influenced by the nature and concentration of the flavonoid in the growth medium, as well as by the substrate used for growth. Sucrose allowed for an optimal induction response for most flavonoids. Some flavonoids, such as flavone and isoflavone, were better inducers of the biphenyl catabolic enzymes than biphenyl itself. We also found that all flavonoids tested in this work were metabolized by strain U23A during co-metabolic growth, but that the metabolite profiles, as well as the level of efficiency of degradation, differed for each flavonoid. To obtain insight into how flavonoids interact with strain U23A to promote polychlorinated biphenyl (PCB degradation, we determined the concentration of

  18. Automated sugar analysis

    Directory of Open Access Journals (Sweden)

    Tadeu Alcides MARQUES

    2016-03-01

    Full Text Available Abstract Sugarcane monosaccharides are reducing sugars, and classical analytical methodologies (Lane-Eynon, Benedict, complexometric-EDTA, Luff-Schoorl, Musson-Walker, Somogyi-Nelson are based on reducing copper ions in alkaline solutions. In Brazil, certain factories use Lane-Eynon, others use the equipment referred to as “REDUTEC”, and additional factories analyze reducing sugars based on a mathematic model. The objective of this paper is to understand the relationship between variations in millivolts, mass and tenors of reducing sugars during the analysis process. Another objective is to generate an automatic model for this process. The work herein uses the equipment referred to as “REDUTEC”, a digital balance, a peristaltic pump, a digital camcorder, math programs and graphics programs. We conclude that the millivolts, mass and tenors of reducing sugars exhibit a good mathematical correlation, and the mathematical model generated was benchmarked to low-concentration reducing sugars (<0.3%. Using the model created herein, reducing sugars analyses can be automated using the new equipment.

  19. Molecular interactions between green tea catechins and cheese fat studied by solid-state nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, Edward J; Hindmarsh, Jason; Everett, David W

    2017-01-15

    Molecular integrations between green tea catechins and milk fat globules in a cheese matrix were investigated using solid-state magic angle spinning nuclear magnetic resonance spectroscopy. Full-fat cheeses were manufactured containing free catechin or free green tea extract (GTE), and liposomal encapsulated catechin or liposomal encapsulated GTE. Molecular mobility of the carbon species in the cheeses was measured by a wide-line separation technique. The (1)H evolution frequency profile of the (13)C peak at 16ppm obtained for the control cheese and cheeses containing encapsulated polyphenols (catechin or GTE) were similar, however, the spectrum was narrower for cheeses containing free polyphenols. Differences in spectral width indicates changes in the molecular mobility of --CH3- or -C-C-PO4- species through hydrophobic and/or cation-π associations between green tea catechins and cheese fat components. However, the similar spectral profile suggests that encapsulation protects cheese fat from interaction with catechins.

  20. The behaviour of green tea catechins in a full-fat milk system under conditions mimicking the cheesemaking process.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-09-01

    Due to their well-known health benefits, green tea catechins have received recent attention as natural additives in foods such as dairy products. However, they may present some irreversible associations with milk components (e.g. protein and milk fat globules). To investigate the behaviour of two important green tea catechins, (+)-catechin (C) and (-)-epigallocatechin gallate (EGCG), in a standard whole milk system under the conditions of cheesemaking, 250 and 500 ppm of each catechin were added to whole milk (3.3% fat). Although both C and EGCG at either concentration increased both total phenolic content and total antioxidant capacity of the subnatants obtained from the milk system, there was a less linear increase when the concentration of the catechins was doubled, whereas C or EGCG were recovered (measured by HPLC) differently. Overall, these results suggest a degree of associations between green tea catechins with milk proteins and milk fat.

  1. Determination the Total Flavonoids from Stem and Leaf of Artabotrys.haimanensis

    Institute of Scientific and Technical Information of China (English)

    BI He-ping; SONG Xiao-Ping; HAN Chang-ri; LI Chuan-bao

    2004-01-01

    The Annonaccac family is a main one of the tropical plants flora and there are totally 127 genus, about 2231 species in the world, wildly distributed in the tropical zone and subtropics areas.China is one of the countries where species of this family are mostly distributed, with 24 genus, 103 species and 6 variant, among which, 45 species and 1 variant are endemic to China. There are about 100 types of plants of Artabotrys genus in the world, among which, 10 species are in China. Scholars from home and abroad have found a series of new substance of biological activities in the plants of Annonaccac family with antimalarial, anti-tumor, anti-leukemia and obvious cardiotonic effects,which has aroused great interest. Plants of Artabotrys genus, Artabotrys Hainanensis are endemic to Hainan, distributed widely in Hainan Island. They have long been used among the ordinary people as medicinal plants with antipyretic, antidotal, antiphlogistic and analgesic effects. The flavonoid is a very important secondary metabolite in plants with many physiological activities such as fat-reduction, antithrombus, antioxidant and blood-sugar-reduction. This paper studies the total flavonoids from stem and leaf of Artabotrys by spectrophotometry. Artabotrys Hainanensis R.E.Fries were collected from Hainan Jianfeng Mountain and were identified. Spectrophotometry was used to determination of the total flavonoids from stem and leaf of Artabotrys. The total flavonoids of Artabotrys were tested with rutin as check sample. By adding aluminium ion agent and controling proper pH, the flavonoids and the aluminium ion were combined into complex compound and the characteristic absorption peak was obtainable in the visible spectrum. The total flavonoids from stem and leaf of Artabotrys were determined to be 2.29% in stem and 6.83% in leaf. The regression equation was Y=0.000786A+0.0058, and the correlation coefficient r=0.9997. This method is easily operated and the result determined is stable and

  2. C-Glycosyltransferases catalyzing the formation of di-C-glucosyl flavonoids in citrus plants.

    Science.gov (United States)

    Ito, Takamitsu; Fujimoto, Shunsuke; Suito, Fumiaki; Shimosaka, Makoto; Taguchi, Goro

    2017-04-02

    Citrus plants accumulate many kinds of flavonoids, including di-C-glucosyl flavonoids, which have attracted considerable attention owing to their health benefits. However, biosynthesis of di-C-glucosyl flavonoids has not been elucidated at the molecular level. Here, we identified the C-glycosyltransferases (CGTs) FcCGT (UGT708G1) and CuCGT (UGT708G2) as the primary enzymes involved in the biosynthesis of di-C-glucosyl flavonoids in the citrus plants kumquat (Fortunella crassifolia) and satsuma mandarin (Citrus unshiu), respectively. The amino acid sequences of these CGTs were 98% identical, indicating that CGT genes are highly conserved in the citrus family. The recombinant enzymes FcCGT and CuCGT utilized 2-hydroxyflavanones, dihydrochalcone, and their mono-C-glucosides as sugar acceptors and produced corresponding di-C-glucosides. The Km and kcat values of FcCGT toward phloretin were C-glucosylphloretin) were 14.4 μM and 5.3 s(-1) , respectively; these values are comparable to those of other glycosyltransferases reported to date. Transcripts of both CGT genes were found to concentrate in various plant organs, and particularly in leaves. Our results suggest that di-C-glucosyl flavonoid biosynthesis proceeds via a single enzyme using either 2-hydroxyflavanones or phloretin as a substrate in citrus plants. In addition, Escherichia coli cells expressing CGT genes were found to be capable of producing di-C-glucosyl flavonoids, which is promising for commercial production of these valuable compounds. This article is protected by copyright. All rights reserved.

  3. Apparatus for drying sugar cubes

    NARCIS (Netherlands)

    Derckx, H.A.J.; Torringa, H.M.

    1999-01-01

    Device for drying sugar cubes containing a heating apparatus for heating and dehumidifying the sugar cubes, a conditioning apparatus for cooling off and possibly further dehumidifying the sugar cubes and a conveying apparatus for conveying the sugar cubes through the heating apparatus and the condit

  4. Apparatus for drying sugar cubes

    NARCIS (Netherlands)

    Derckx, H.A.J.; Torringa, H.M.

    1999-01-01

    Device for drying sugar cubes containing a heating apparatus for heating and dehumidifying the sugar cubes, a conditioning apparatus for cooling off and possibly further dehumidifying the sugar cubes and a conveying apparatus for conveying the sugar cubes through the heating apparatus and the

  5. The Sugar Tax in Holland

    NARCIS (Netherlands)

    Ajjaji, Fadoua

    2016-01-01

    This inquiry supports the theory of a sugar tax has a positive influence on the sugar consumption of Dutch individuals. Once a tax is implemented, the sugar consumption declines. Furthermore, this study supported the hypothesis claiming that children have a positive influence on their parental sugar

  6. Apparatus for drying sugar cubes

    NARCIS (Netherlands)

    Derckx, H.A.J.; Torringa, H.M.

    1999-01-01

    Device for drying sugar cubes containing a heating apparatus for heating and dehumidifying the sugar cubes, a conditioning apparatus for cooling off and possibly further dehumidifying the sugar cubes and a conveying apparatus for conveying the sugar cubes through the heating apparatus and the condit

  7. The Sugar Tax in Holland

    NARCIS (Netherlands)

    Ajjaji, Fadoua

    2016-01-01

    This inquiry supports the theory of a sugar tax has a positive influence on the sugar consumption of Dutch individuals. Once a tax is implemented, the sugar consumption declines. Furthermore, this study supported the hypothesis claiming that children have a positive influence on their parental sugar

  8. Inhibition of proliferation of human lung cancer cells by green tea catechins is mediated by upregulation of let-7

    OpenAIRE

    ZHONG, ZHIWEI; Dong, Zhuo; Yang, Lihua; Chen, Xiaoqiang; Gong, Zhaohui

    2012-01-01

    Green tea catechins are known to function as anticancer agents via inhibition of carcinogenesis during the initiation, promotion and progression stages. Many potential mechanisms have been proposed, yet the precise mechanism of lung cancer prevention by green tea catechins remains unclear. microRNAs (miRs) are a class of 21–24 nucleotide small non-coding RNAs and play critical roles throughout cellular development and regulation. Emerging evidence demonstrates that tea catechins influence the...

  9. Antiprotozoal, Antibacterial and Antidiarrheal Properties from the Flowers of Chiranthodendron pentadactylon and Isolated Flavonoids

    Science.gov (United States)

    Calzada, Fernando; Juárez, Teresa; García-Hernández, Normand; Valdes, Miguel; Ávila, Oscar; Mulia, Lilian Yepez; Velázquez, Claudia

    2017-01-01

    Background: Chiranthodendron pentadactylon Larreat. (Sterculiaceae) is a Mexican plant used in traditional medicine for the treatment of heart disease symptoms and infectious diarrhea. Objective: To evaluate in vitro antiprotozoal and antibacterial activities and in vivo antidiarrheal activity from the flowers of C. pentadactylon using the extract, fractions, and major isolated flavonoids. Materials and methods: Bioassay-guided fractionation of the methanol extract of C. pentadactylon (MECP) led to the isolation of five flavonoids, tiliroside, astragalin, isoquercitrin, (+)-catechin, and (-)-epicatechin. Antimicrobial activities were tested on two protozoa (Entamoeba histolytica and Giardia lamblia) and nine bacterial enteropathogens (two Escherichia coli strains, two Shigella sonnei strains, two Shigella flexneri strains, two Salmonella sp. strains, and Vibrio cholerae) isolated from feces of children with acute diarrhea or dysentery and resistant to chloramphenicol. Also, antidiarrheal activity was tested on cholera toxin-induced diarrhea in male Balb-c mice. Results: Epicatechin was the most potent antiamoebic and antigiardial compound with IC50 values of 1.9 μg/mL for E. histolytica and 1.6 μg/mL for G. lamblia; tiliroside showed moderate antiprotozoal activity against both protozoan. In contrast, in the antibacterial activity, tiliroside was the most potent compound on all microorganisms with minimum inhibitory concentration values less than 0.7 mg/mL. In the case of cholera toxin-induced diarrhea, epicatechin was the most potent flavonoid with IC50 of 14.7 mg/kg. Conclusion: Epicatechin and tiliroside were the flavonoids responsible for antimicrobial andantidiarrheal activities of C. pentadactylon. Its antiprotozoal, antibacterial, and antidiarrheal properties are in good agreement with the traditional medicinal use of C. pentadactylon for the treatment of infectious diarrhea. SUMMARY Epicatechin was the most potent antiamoebic and antigiardial compound

  10. Synthesis of Phenolics and Flavonoids in Ginger (Zingiber officinale Roscoe and Their Effects on Photosynthesis Rate

    Directory of Open Access Journals (Sweden)

    Asmah Rahmat

    2010-11-01

    Full Text Available The relationship between phenolics and flavonoids synthesis/accumulation and photosynthesis rate was investigated for two Malaysian ginger (Zingiber officinale varieties grown under four levels of glasshouse light intensity, namely 310, 460, 630 and 790 μmol m−2s−1. High performance liquid chromatography (HPLC was employed to identify and quantify the polyphenolic components. The results of HPLC analysis indicated that synthesis and partitioning of quercetin, rutin, catechin, epicatechin and naringenin were high in plants grown under 310 µmol m−2s−1. The average value of flavonoids synthesis in leaves for both varieties increased (Halia Bentong 26.1%; Halia Bara 19.5% when light intensity decreased. Photosynthetic rate and plant biomass increased in both varieties with increasing light intensity. More specifically, a high photosynthesis rate (12.25 µmol CO2 m−2s−1 in Halia Bara and plant biomass (79.47 g in Halia Bentong were observed at 790 µmol m−2s−1. Furthermore, plants with the lowest rate of photosynthesis had highest flavonoids content. Previous studies have shown that quercetin inhibits and salicylic acid induces the electron transport rate in photosynthesis photosystems. In the current study, quercetin was an abundant flavonoid in both ginger varieties. Moreover, higher concentration of quercetin (1.12 mg/g dry weight was found in Halia Bara leaves grown under 310 µmol m−2s−1 with a low photosynthesis rate. Furthermore, a high content of salicylic acid (0.673 mg/g dry weight was detected in Halia Bara leaves exposed under 790 µmol m−2s−1 with a high photosynthesis rate. No salicylic acid was detected in gingers grown under 310 µmol m−2s−1. Ginger is a semi-shade loving plant that does not require high light intensity for photosynthesis. Different photosynthesis rates at different light intensities may be related to the absence or presence of some flavonoid and phenolic compounds.

  11. Green tea catechins prevent low-density lipoprotein oxidation via their accumulation in low-density lipoprotein particles in humans.

    Science.gov (United States)

    Suzuki-Sugihara, Norie; Kishimoto, Yoshimi; Saita, Emi; Taguchi, Chie; Kobayashi, Makoto; Ichitani, Masaki; Ukawa, Yuuichi; Sagesaka, Yuko M; Suzuki, Emiko; Kondo, Kazuo

    2016-01-01

    Green tea is rich in polyphenols, including catechins which have antioxidant activities and are considered to have beneficial effects on cardiovascular health. In the present study, we investigated the effects of green tea catechins on low-density lipoprotein (LDL) oxidation in vitro and in human studies to test the hypothesis that catechins are incorporated into LDL particles and exert antioxidant properties. In a randomized, placebo-controlled, double-blind, crossover trial, 19 healthy men ingested green tea extract (GTE) in the form of capsules at a dose of 1 g total catechin, of which most (>99%) was the gallated type. At 1 hour after ingestion, marked increases of the plasma concentrations of (-)-epigallocatechin gallate and (-)-epicatechin gallate were observed. Accordingly, the plasma total antioxidant capacity was increased, and the LDL oxidizability was significantly reduced by the ingestion of GTE. We found that gallated catechins were incorporated into LDL particles in nonconjugated forms after the incubation of GTE with plasma in vitro. Moreover, the catechin-incorporated LDL was highly resistant to radical-induced oxidation in vitro. An additional human study with 5 healthy women confirmed that GTE intake sufficiently increased the concentration of gallated catechins, mainly in nonconjugated forms in LDL particles, and reduced the oxidizability of LDL. In conclusion, green tea catechins are rapidly incorporated into LDL particles and play a role in reducing LDL oxidation in humans, which suggests that taking green tea catechins is effective in reducing atherosclerosis risk associated with oxidative stress.

  12. Enzymatic activity of cell-free extracts from Burkholderia oxyphila OX-01 bio-converts (+)-catechin and (-)-epicatechin to (+)-taxifolin.

    Science.gov (United States)

    Otsuka, Yuichiro; Matsuda, Motoki; Sonoki, Tomonori; Sato-Izawa, Kanna; Goodell, Barry; Jelison, Jody; Navarro, Ronald R; Murata, Hitoshi; Nakamura, Masaya

    2016-12-01

    This study characterized the enzymatic ability of a cell-free extract from an acidophilic (+)-catechin degrader Burkholderia oxyphila (OX-01). The crude OX-01 extracts were able to transform (+)-catechin and (-)-epicatechin into (+)-taxifolin via a leucocyanidin intermediate in a two-step oxidation. Enzymatic oxidation at the C-4 position was carried out anaerobically using H2O as an oxygen donor. The C-4 oxidation occurred only in the presence of the 2R-catechin stereoisomer, with the C-3 stereoisomer not affecting the reaction. These results suggest that the OX-01 may have evolved to target both (+)-catechin and (-)-epicatechin, which are major structural units in plants.

  13. Inhibition of proliferation of human lung cancer cells by green tea catechins is mediated by upregulation of let-7.

    Science.gov (United States)

    Zhong, Zhiwei; Dong, Zhuo; Yang, Lihua; Chen, Xiaoqiang; Gong, Zhaohui

    2012-08-01

    Green tea catechins are known to function as anticancer agents via inhibition of carcinogenesis during the initiation, promotion and progression stages. Many potential mechanisms have been proposed, yet the precise mechanism of lung cancer prevention by green tea catechins remains unclear. microRNAs (miRs) are a class of 21-24 nucleotide small non-coding RNAs and play critical roles throughout cellular development and regulation. Emerging evidence demonstrates that tea catechins influence the expression of miRs in human cancer cells to inhibit tumorigenesis. Both let-7a-1 and let-7g were detected in the human lung cancer cells treated with tea catechins. The cell viability and cell cycle were analyzed after tea catechins treatment. In the present study, we found that tea catechins upregulated the tumor-suppressor miRs, let-7a-1 and let-7g, in lung cancer cell lines. The upregulation of let-7a/7g repressed the expression of their targets, C-MYC and the regulatory protein of LIN-28, at the mRNA and protein levels. Moreover, the cell growth assay indicated that tea catechins significantly inhibited cell proliferation, and the flow cytometric analysis revealed an increase in the number of cells in the G2/M phase and a decrease in the number of cells in the S phase after treatment with tea catechins. These observations suggest that green tea catechins mediate the inhibition of proliferation of lung cancer cells through the let-7 signaling pathway.

  14. Synthesis of calixarenes and their extraction performance for ester catechins

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A series of extractants (tert-butylcalix[6]arene, tert-butylcalix[8]arene and octeacetate of tert-butylcalix[8]arene) were synthesized, and their structures were identified by IR and 1H-NMR. The distribution behavior of ester catechins monomer in the aqueous and chloroform two-phase system containing one of calixarene was studied. The influences of different extractants,concentration of tert-butylcalix[8]arene and extraction temperature on the partition coefficients and the separation factors were investigated. The experiment results show that tert-butylcalix[8]arene is the best extractant that forms a more stable supramolecular compound with gallocatechin gallate (GCG) than with epigallocathechin gallate (EGCG) or epicatechin gallate (ECG). When the concentration ofp-tert-butylcalix[8]arene is 3.79 mmol/L, the extraction temperature is 4 ℃C, the partition coefficients of KGG cG, KECG,KEGG cG are 0.987, 0.629, 0.449, the separation factors ofα1 and α2 are 1.450 and 1.596, respectively. The important factors influencing the extraction properties of calixarene are discovered to be its cavity size and hydrogen bonding.

  15. Chemopreventive Potential of Green Tea Catechins in Hepatocellular Carcinoma

    Directory of Open Access Journals (Sweden)

    Masahito Shimizu

    2015-03-01

    Full Text Available Hepatocellular carcinoma (HCC, which is a common malignancy worldwide, usually develops in a cirrhotic liver due to hepatitis virus infection. Metabolic syndrome, which is frequently complicated by obesity and diabetes mellitus, is also a critical risk factor for liver carcinogenesis. Green tea catechins (GTCs may possess potent anticancer and chemopreventive properties for a number of different malignancies, including liver cancer. Antioxidant and anti-inflammatory activities are key mechanisms through which GTCs prevent the development of neoplasms, and they also exert cancer chemopreventive effects by modulating several signaling transduction and metabolic pathways. Furthermore, GTCs are considered to be useful for the prevention of obesity- and metabolic syndrome-related carcinogenesis by improving metabolic disorders. Several interventional trials in humans have shown that GTCs may ameliorate metabolic abnormalities and prevent the development of precancerous lesions. The purpose of this article is to review the key mechanisms by which GTCs exert chemopreventive effects in liver carcinogenesis, focusing especially on their ability to inhibit receptor tyrosine kinases and improve metabolic abnormalities. We also review the evidence for GTCs acting to prevent metabolic syndrome-associated liver carcinogenesis.

  16. A functional genomics approach to (iso)flavonoid glycosylation in the model legume Medicago truncatula.

    Science.gov (United States)

    Modolo, Luzia V; Blount, Jack W; Achnine, Lahoucine; Naoumkina, Marina A; Wang, Xiaoqiang; Dixon, Richard A

    2007-07-01

    Analysis of over 200,000 expressed sequence tags from a range of Medicago truncatula cDNA libraries resulted in the identification of over 150 different family 1 glycosyltransferase (UGT) genes. Of these, 63 were represented by full length clones in an EST library collection. Among these, 19 gave soluble proteins when expressed in E. coli, and these were screened for catalytic activity against a range of flavonoid and isoflavonoid substrates using a high-throughput HPLC assay method. Eight UGTs were identified with activity against isoflavones, flavones, flavonols or anthocyanidins, and several showed high catalytic specificity for more than one class of (iso)flavonoid substrate. All tested UGTs preferred UDP-glucose as sugar donor. Phylogenetic analysis indicated that the Medicago (iso)flavonoid glycosyltransferase gene sequences fell into a number of different clades, and several clustered with UGTs annotated as glycosylating non-flavonoid substrates. Quantitative RT-PCR and DNA microarray analysis revealed unique transcript expression patterns for each of the eight UGTs in Medicago organs and cell suspension cultures, and comparison of these patterns with known phytochemical profiles suggested in vivo functions for several of the enzymes.

  17. Bioactive flavonoids from Kaempferia parviflora.

    Science.gov (United States)

    Yenjai, Chavi; Prasanphen, Khanchara; Daodee, Supawadee; Wongpanich, Varima; Kittakoop, Prasat

    2004-01-01

    Nine flavonoids (1-9) have been isolated from Kaempferia parviflora. Among these, 5,7,4'-trimethoxyflavone (8) and 5,7,3',4'-tetramethoxyflavone (9) exhibited antiplasmodial activity against Plasmodium falciparum, with IC50 values of 3.70 and 4.06 microg/ml, respectively. 3,5,7,4'-Tetramethoxyflavone (7) and compound 8 possessed antifungal activity against Candida albicans with respective IC50 values of 39.71 and 17.63 microg/ml, and also showed mild antimycobacterial activity with the minimum inhibitory concentrations (MIC) of 200 and 50 microg/ml, respectively. However, none of the isolated compounds demonstrated cytotoxicity against KB, BC and NCI-H187 cell lines.

  18. Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen Species

    Directory of Open Access Journals (Sweden)

    Mohd Farhan

    2016-02-01

    Full Text Available Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C, epicatechin (EC, epigallocatechin (EGC and epigallocatechin-3-gallate (EGCG are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells.

  19. Systemic Absorption of Catechins after Intraruminal or Intraduodenal Application of a Green Tea Extract in Cows.

    Science.gov (United States)

    Wein, Silvia; Beyer, Birgit; Gohlke, Annika; Blank, Ralf; Metges, Cornelia C; Wolffram, Siegfried

    2016-01-01

    Green tea catechins have various potential health benefits in humans including anti-inflammatory, anti-oxidative and hepato-protective effects. If present in the circulation, they might have similar effects in ruminants, which are exposed to oxidative stress and fatty liver disease such as dairy cows during the periparturient phase. However, the bioavailability of a substance is a prerequisite for any post absorptive effect in vivo. This study aimed to investigate the appearance of catechins from a green tea extract (GTE) in cattle plasma after intraruminal and intraduodenal administration because absorption is of major importance regarding the bioavailability of catechins. The studies were performed in 5 rumen-fistulated non-lactating heifers and 6 duodenally fistulated lactating dairy cows, respectively, equipped with indwelling catheters placed in a jugular vein. The GTE was applied intraruminally (10 and 50 mg/kg BW, heifers) or duodenally (10, 20 and 30 mg/kg BW, dairy cows) in a cross-over design with a 2 d washout period between different dosages. Blood samples were drawn following the GTE administration at various pre-defined time intervals. The concentration of the major GTE catechins (gallocatechin, epigallocatechin, catechin, epicatechin, epigallocatechin-gallate, epicatechin-gallate) in plasma samples were analysed by HPLC with electrochemical detection. Irrespective of the dose, almost none of the catechins originally contained in the GTE were detected in plasma samples after intraruminal application. In contrast, intraduodenal administration of GTE resulted in increased plasma concentrations of epicatechin, epigallocatechin, epigallocatechin gallate in a dose-dependent manner. Thus, we can conclude that intraruminally or orally administered catechins are intensively metabolized by ruminal microorganisms.

  20. Systemic Absorption of Catechins after Intraruminal or Intraduodenal Application of a Green Tea Extract in Cows.

    Directory of Open Access Journals (Sweden)

    Silvia Wein

    Full Text Available Green tea catechins have various potential health benefits in humans including anti-inflammatory, anti-oxidative and hepato-protective effects. If present in the circulation, they might have similar effects in ruminants, which are exposed to oxidative stress and fatty liver disease such as dairy cows during the periparturient phase. However, the bioavailability of a substance is a prerequisite for any post absorptive effect in vivo. This study aimed to investigate the appearance of catechins from a green tea extract (GTE in cattle plasma after intraruminal and intraduodenal administration because absorption is of major importance regarding the bioavailability of catechins. The studies were performed in 5 rumen-fistulated non-lactating heifers and 6 duodenally fistulated lactating dairy cows, respectively, equipped with indwelling catheters placed in a jugular vein. The GTE was applied intraruminally (10 and 50 mg/kg BW, heifers or duodenally (10, 20 and 30 mg/kg BW, dairy cows in a cross-over design with a 2 d washout period between different dosages. Blood samples were drawn following the GTE administration at various pre-defined time intervals. The concentration of the major GTE catechins (gallocatechin, epigallocatechin, catechin, epicatechin, epigallocatechin-gallate, epicatechin-gallate in plasma samples were analysed by HPLC with electrochemical detection. Irrespective of the dose, almost none of the catechins originally contained in the GTE were detected in plasma samples after intraruminal application. In contrast, intraduodenal administration of GTE resulted in increased plasma concentrations of epicatechin, epigallocatechin, epigallocatechin gallate in a dose-dependent manner. Thus, we can conclude that intraruminally or orally administered catechins are intensively metabolized by ruminal microorganisms.

  1. Catechin-induced activation of the LKB1/AMP-activated protein kinase pathway.

    Science.gov (United States)

    Murase, Takatoshi; Misawa, Koichi; Haramizu, Satoshi; Hase, Tadashi

    2009-07-01

    Catechins are abundant in green tea and induce a variety of biologic actions, including anti-cancer, anti-obesity, and anti-diabetes effects, and their clinical application has been widely investigated. To clarify the underlying molecular mechanisms of these actions, we examined the effect of catechins on AMP-activated protein kinase (AMPK) in cultured cells and in mice. In Hepa 1-6, L6, and 3T3-L1 cells, epigallocatechin gallate (EGCG) induced increases in AMPKalpha and the downstream target acetyl-CoA carboxylase (ACC) phosphorylation, and AMPKalpha activity. Analysis of the molecular specificity of eight naturally occurring catechins revealed that catechins with a gallocatechin moiety or a galloyl residue act as AMPK activators. In addition, phosphorylation of LKB1, which is a tumor-suppressor protein and a major AMPK-kinase, was increased by catechin treatment. EGCG-induced phosphorylation of LKB1 and AMPKalpha was suppressed by treatment with catalase, suggesting that reactive oxygen species are involved in EGCG-induced activation of the LKB1/AMPK pathway. Oral administration of EGCG (200mg/kg body weight) to BALB/c mice induced an increase in AMPKalpha activity in the liver concomitant with a significant increase in AMPKalpha and ACC phosphorylation. EGCG administration also increased oxygen consumption and fat oxidation, as determined by indirect calorimetry. These findings suggest that multiple effects of catechins, including anti-obesity and anti-cancer effects, are mediated, at least in part, by the activation of LKB1/AMPK in various tissues, and that these effects vary according to the catechin structure.

  2. Cancer Therapy by Catechins Involves Redox Cycling of Copper Ions and Generation of Reactive Oxygen species.

    Science.gov (United States)

    Farhan, Mohd; Khan, Husain Yar; Oves, Mohammad; Al-Harrasi, Ahmed; Rehmani, Nida; Arif, Hussain; Hadi, Sheikh Mumtaz; Ahmad, Aamir

    2016-02-04

    Catechins, the dietary phytochemicals present in green tea and other beverages, are considered to be potent inducers of apoptosis and cytotoxicity to cancer cells. While it is believed that the antioxidant properties of catechins and related dietary agents may contribute to lowering the risk of cancer induction by impeding oxidative injury to DNA, these properties cannot account for apoptosis induction and chemotherapeutic observations. Catechin (C), epicatechin (EC), epigallocatechin (EGC) and epigallocatechin-3-gallate (EGCG) are the four major constituents of green tea. In this article, using human peripheral lymphocytes and comet assay, we show that C, EC, EGC and EGCG cause cellular DNA breakage and can alternatively switch to a prooxidant action in the presence of transition metals such as copper. The cellular DNA breakage was found to be significantly enhanced in the presence of copper ions. Catechins were found to be effective in providing protection against oxidative stress induced by tertbutylhydroperoxide, as measured by oxidative DNA breakage in lymphocytes. The prooxidant action of catechins involved production of hydroxyl radicals through redox recycling of copper ions. We also determined that catechins, particularly EGCG, inhibit proliferation of breast cancer cell line MDA-MB-231 leading to a prooxidant cell death. Since it is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies, cancer cells would be more subject to redox cycling between copper ions and catechins to generate reactive oxygen species (ROS) responsible for DNA breakage. Such a copper dependent prooxidant cytotoxic mechanism better explains the anticancer activity and preferential cytotoxicity of dietary phytochemicals against cancer cells.

  3. The impact of microbial biotransformation of catechin in enhancing the allelopathic effects of Rhododendron formosanum.

    Directory of Open Access Journals (Sweden)

    Chao-Min Wang

    Full Text Available Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (--catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (--catechin as the carbon source and catalyzed the conversion of (--catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (--catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (--catechin did and the effect of (--catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise

  4. The impact of microbial biotransformation of catechin in enhancing the allelopathic effects of Rhododendron formosanum.

    Science.gov (United States)

    Wang, Chao-Min; Li, Tsai-Chi; Jhan, Yun-Lian; Weng, Jen-Hsien; Chou, Chang-Hung

    2013-01-01

    Rhododendron formosanum is distributed widely in the central mountains in Taiwan and the major allelopathic compound in the leaves has been identified as (-)-catechin, which is also a major allelochemical of an invasive spotted knapweed in North America. Soil microorganisms play key roles in ecosystems and influence various important processes, including allelopathy. However, no microorganism has been identified as an allelochemical mediator. This study focused on the role of microorganisms in the allelopathic effects of R. formosanum. The microorganism population in the rhizosphere of R. formosanum was investigated and genetic analysis revealed that the predominant genera of microorganisms in the rhizosphere of R. formosanum were Pseudomonas, Herbaspirillum, and Burkholderia. The dominant genera Pseudomonas utilized (-)-catechin as the carbon source and catalyzed the conversion of (-)-catechin into protocatechuic acid in vitro. The concentrations of allelochemicals in the soil were quantified by liquid chromatography-electrospray ionization/tandem mass spectrometry. The concentration of (-)-catechin in the soil increased significantly during the extreme rainfall in the summer season and suppressed total bacterial populations. Protocatechuic acid accumulation was observed while total bacterial populations increased abundantly in both laboratory and field studies. Allelopathic interactions were tested by evaluating the effects of different allelochemicals on the seed germination, radicle growth, and photosynthesis system II of lettuce. Protocatechuic acid exhibited higher phytotoxicity than (-)-catechin did and the effect of (-)-catechin on the inhibition of seed germination was enhanced by combining it with protocatechuic acid at a low concentration. This study revealed the significance of the allelopathic interactions between R. formosanum and microorganisms in the rhizosphere. These findings demonstrate that knowledge regarding the precise biotransformation

  5. Flavonoid regulation of EAG1 channels

    Science.gov (United States)

    Carlson, Anne E.; Brelidze, Tinatin I.

    2013-01-01

    The voltage-gated, K+-selective ether á go-go 1 (EAG1) channel is expressed throughout the brain where it is thought to regulate neuronal excitability. Besides its normal physiological role in the brain, EAG1 is abnormally expressed in several cancer cell types and promotes tumor progression. Like all other channels in the KCNH family, EAG1 channels have a large intracellular carboxy-terminal region that shares structural similarity with cyclic nucleotide–binding homology domains (CNBHDs). EAG1 channels, however, are not regulated by the direct binding of cyclic nucleotides and have no known endogenous ligands. In a screen of biological metabolites, we have now identified four flavonoids as potentiators of EAG1 channels: fisetin, quercetin, luteolin, and kaempferol. These four flavonoids shifted the voltage dependence of activation toward more hyperpolarizing potentials and slowed channel deactivation. All four flavonoids regulated channel gating with half-maximal concentrations of 2–8 µM. The potentiation of gating did not require the amino-terminal or post-CNBHD regions of EAG1 channels. However, in fluorescence resonance energy transfer and anisotropy-based binding assays, flavonoids bound to the purified CNBHD of EAG1 channels. The CNBHD of KCNH channels contains an intrinsic ligand, a conserved stretch of residues that occupy the cyclic nucleotide–binding pocket. Mutations of the intrinsic ligand in EAG1 (Y699A) potentiated gating similar to flavonoids, and flavonoids did not further potentiate EAG1-Y699A channels. Furthermore, the Y699A mutant CNBHD bound to flavonoids with higher affinity than wild-type CNBHD. These results suggest that the flavonoids identified here potentiated EAG1 channels by binding to the CNBHD, possibly by displacing their intrinsic ligand. EAG1 channels should be considered as a possible target for the physiological effects of flavonoids. PMID:23440277

  6. Elevated carbon dioxide increases contents of flavonoids and phenolic compounds, and antioxidant activities in Malaysian young ginger (Zingiber officinale Roscoe.) varieties.

    Science.gov (United States)

    Ghasemzadeh, Ali; Jaafar, Hawa Z E; Rahmat, Asmah

    2010-11-03

    Zingiber officinale Roscoe. (Family Zingiberaceae) is well known in Asia. The plant is widely cultivated in village gardens in the tropics for its medicinal properties and as a marketable spice in Malaysia. Ginger varieties are rich in physiologically active phenolics and flavonoids with a range of pharmacological activities. Experiments were conducted to determine the feasibility of increasing levels of flavonoids (quercetin, rutin, catechin, epicatechin, kaempferol, naringenin, fisetin and morin) and phenolic acid (gallic acid, vanillic acid, ferulic acid, tannic acid, cinnamic acid and salicylic acid), and antioxidant activities in different parts of Malaysian young ginger varieties (Halia Bentong and Halia Bara) with CO(2) enrichment in a controlled environment system. Both varieties showed an increase in phenolic compounds and flavonoids in response to CO(2) enrichment from 400 to 800 µmol mol-1 CO(2). These increases were greater in rhizomes compared to leaves. High performance liquid chromatography (HPLC) results showed that quercetin and gallic acid were the most abundant flavonoid and phenolic acid in Malaysian young ginger varieties. Under elevated CO(2) conditions, kaempferol and fisetin were among the flavonoid compounds, and gallic acid and vanillic acid were among the phenolic compounds whose levels increased in both varieties. As CO(2) concentration was increased from 400 to 800 µmol mol-1, free radical scavenging power (DPPH) increased about 30% in Halia Bentong and 21.4% in Halia Bara; and the rhizomes exhibited more enhanced free radical scavenging power, with 44.9% in Halia Bentong and 46.2% in Halia Bara. Leaves of both varieties also displayed good levels of flavonoid compounds and antioxidant activities. These results indicate that the yield and pharmaceutical quality of Malaysian young ginger varieties can be enhanced by controlled environment production and CO(2) enrichment.

  7. Elevated Carbon Dioxide Increases Contents of Flavonoids and Phenolic Compounds, and Antioxidant Activities in Malaysian Young Ginger (Zingiber officinale Roscoe. Varieties

    Directory of Open Access Journals (Sweden)

    Asmah Rahmat

    2010-11-01

    Full Text Available Zingiber officinale Roscoe. (Family Zingiberaceae is well known in Asia. The plant is widely cultivated in village gardens in the tropics for its medicinal properties and as a marketable spice in Malaysia. Ginger varieties are rich in physiologically active phenolics and flavonoids with a range of pharmacological activities. Experiments were conducted to determine the feasibility of increasing levels of flavonoids (quercetin, rutin, catechin, epicatechin, kaempferol, naringenin, fisetin and morin and phenolic acid (gallic acid, vanillic acid, ferulic acid, tannic acid, cinnamic acid and salicylic acid, and antioxidant activities in different parts of Malaysian young ginger varieties (Halia Bentong and Halia Bara with CO2 enrichment in a controlled environment system. Both varieties showed an increase in phenolic compounds and flavonoids in response to CO2 enrichment from 400 to 800 µmol mol-1 CO2. These increases were greater in rhizomes compared to leaves. High performance liquid chromatography (HPLC results showed that quercetin and gallic acid were the most abundant flavonoid and phenolic acid in Malaysian young ginger varieties. Under elevated CO2 conditions, kaempferol and fisetin were among the flavonoid compounds, and gallic acid and vanillic acid were among the phenolic compounds whose levels increased in both varieties. As CO2 concentration was increased from 400 to 800 µmol mol-1, free radical scavenging power (DPPH increased about 30% in Halia Bentong and 21.4% in Halia Bara; and the rhizomes exhibited more enhanced free radical scavenging power, with 44.9% in Halia Bentong and 46.2% in Halia Bara. Leaves of both varieties also displayed good levels of flavonoid compounds and antioxidant activities. These results indicate that the yield and pharmaceutical quality of Malaysian young ginger varieties can be enhanced by controlled environment production and CO2 enrichment.

  8. Intestinal sugar transport

    Institute of Scientific and Technical Information of China (English)

    Laurie A Drozdowski; Alan BR Thomson

    2006-01-01

    Carbohydrates are an important component of the diet.The carbohydrates that we ingest range from simple monosaccharides (glucose, fructose and galactose) to disaccharides (lactose, sucrose) to complex polysaccharides. Most carbohydrates are digested by salivary and pancreatic amylases, and are further broken down into monosaccharides by enzymes in the brush border membrane (BBM) of enterocytes. For example, lactase-phloridzin hydrolase and sucraseisomaltase are two disaccharidases involved in the hydrolysis of nutritionally important disaccharides. Once monosaccharides are presented to the BBM, mature enterocytes expressing nutrient transporters transport the sugars into the enterocytes. This paper reviews the early studies that contributed to the development of a working model of intestinal sugar transport, and details the recent advances made in understanding the process by which sugars are absorbed in the intestine.

  9. Green tea catechins enhance norepinephrine-induced lipolysis via a protein kinase A-dependent pathway in adipocytes.

    Science.gov (United States)

    Chen, Shu; Osaki, Noriko; Shimotoyodome, Akira

    2015-05-22

    Green tea catechins have been shown to attenuate obesity in animals and humans. The catechins activate adenosine monophosphate-activated protein kinase (AMPK), and thereby increase fatty acid oxidation in liver and skeletal muscles. Green tea catechins have also been shown to reduce body fat in humans. However, the effect of the catechins on lipolysis in adipose tissue has not been fully understood. The aim of this study was to clarify the effect of green tea catechins on lipolysis in adipocytes and to elucidate the underlying mechanism. Differentiated mouse adipocyte cell line (3T3-L1) was stimulated with green tea catechins in the presence or absence of norepinephrine. Glycerol and free fatty acids in the media were measured. Phosphorylation of hormone-sensitive lipase (HSL) was determined by Western blotting, and the mRNA expression levels of HSL, adipose triglyceride lipase (ATGL), and perilipin were determined by quantitative RT-PCR. The cells were treated with inhibitors of protein kinase A (PKA), protein kinase C (PKC), protein kinase G (PKG), or mitogen-activated protein kinase (MAPK) to determine the responsible pathway. Treatment of 3T3-L1 adipocytes with green tea catechins increased the level of glycerol and free fatty acids released into the media in the presence, but not absence, of norepinephrine, and increased the level of phosphorylated HSL in the cells. The catechins also increased mRNA and protein levels of HSL and ATGL. PKA inhibitor (H89) attenuated the catechin-induced increase in glycerol release and HSL phosphorylation. The results demonstrate that green tea catechins enhance lipolysis in the presence of norepinephrine via a PKA-dependent pathway in 3T3-L1 adipocytes, providing a potential mechanism by which green tea catechins could reduce body fat.

  10. The potential role of green tea catechins in the prevention of the metabolic syndrome - a review.

    Science.gov (United States)

    Thielecke, Frank; Boschmann, Michael

    2009-01-01

    The metabolic syndrome (MetS) represents an emerging health burden for governments and health care providers. Particularly relevant for prevention and early management of MetS are lifestyle conditions including physical activity and the diet. It has been shown that green tea, when consumed on a daily basis, supports health. Many of the beneficial effects of green tea are related to its catechin, particularly (-)-epigallocatechin-3-gallate (EGCG), content. There is conclusive evidence from in vitro and animal studies which provide the concepts for underlying functional mechanisms of green tea catechins and their biological actions. An increasing number of human studies have explored the effects of green tea catechins on the major MetS conditions such as obesity, type-2 diabetes and cardiovascular risk factors. This article provides a comprehensive overview of the human studies addressing the potential benefits of green tea catechins on the MetS. The number of human studies in this field is still limited. However, the majority of human epidemiological and intervention studies demonstrate beneficial effects of green tea or green tea extracts, rich in EGCG on weight management, glucose control and cardiovascular risk factors. The optimal dose has not yet been established. The current body of evidence in humans warrants further attention. In particular, well-controlled long-term human studies would help to fully understand the protective effects of green tea catechins on parameters related to the MetS.

  11. The green tea catechin epigallocatechin gallate (EGCG blocks cell motility, chemotaxis and development in Dictyostelium discoideum.

    Directory of Open Access Journals (Sweden)

    Kyle J McQuade

    Full Text Available Catechins, flavanols found at high levels in green tea, have received significant attention due to their potential health benefits related to cancer, autoimmunity and metabolic disease, but little is known about the mechanisms by which these compounds affect cellular behavior. Here, we assess whether the model organism Dictyostelium discoideum is a useful tool with which to characterize the effects of catechins. Epigallocatechin gallate (EGCG, the most abundant and potent catechin in green tea, has significant effects on the Dictyostelium life cycle. In the presence of EGCG aggregation is delayed, cells do not stream and development is typically stalled at the loose aggregate stage. The developmental effects very likely result from defects in motility, as EGCG reduces both random movement and chemotaxis of Dictyostelium amoebae. These results suggest that catechins and their derivatives may be useful tools with which to better understand cell motility and development in Dictyostelium and that this organism is a useful model to further characterize the activities of catechins.

  12. Combination therapy with catechins and caffeine inhibits fat accumulation in 3T3-L1 cells

    Science.gov (United States)

    Zhu, Xiaojuan; Yang, Licong; Xu, Feng; Lin, Lezhen; Zheng, Guodong

    2017-01-01

    Catechins and caffeine, which are green tea components, have a slimming effect; however, the combinational effect of fat metabolism in 3T3-L1 cells remains unclear. In the present study, 3T3-L1 cells were treated with catechins and caffeine in combination, and it was found that combination therapy with catechins and caffeine markedly reduced intracellular fat accumulation, mRNA expression levels of peroxisome proliferator-activated receptor-γ and CCAAT/enhancer-binding protein α in the early stage of cell differentiation were significantly reduced, and mRNA expression of fatty acid synthetase(FAS) andglycerol-3-phosphate dehydrogenase protein expression levels of FAS were downregulated. Noradrenaline-induced lipolysis was enhanced by caffeine, which markedly increased the protein expression of adipose triglyceride lipase and hormone sensitive lipase. These results indicated that combination therapy with catechins and caffeine synergistically inhibited lipid accumulation by regulating the gene and protein expression levels of lipid metabolism-related enzymes. Therefore, catechins and caffeine combination therapy has potential as a functional food that may be used to prevent obesity and lifestyle-associated diseases. PMID:28352352

  13. Comparison of Some Extraction Methods for Isolation of Catechins and Caffeine from Turkish Green Tea

    Directory of Open Access Journals (Sweden)

    Ezgi DEMİR

    2015-07-01

    Full Text Available Effective extraction of anticancer and antioxidant principles from Turkish green tea were main purpose of this work. The pre-optimized experimental condition for liquid extraction was employed for comparative appraisal.  Not only extraction methods also nature of the green tea samples (fresh, dried or frozen and quantitative yields related to collection periods were investigated.  After extraction of the green tea with various techniques the extract was partitioned with chloroform to remove caffeine, after that the extract was partitioned with ethyl acetate to obtain catechin mixture. Quantification of individual catechins was carried out by HPLC and analysis results proved that epigallocatechin gallate (EGCG was main catechin specie present in all extracts. The results indicate that hot water extraction (at 80 0C provides higher catechin yield when compared to other methods. The highest extract yields were obtained with dried leaves collected in second collection period. The crude catechin mixture contains high amount of EGCG and might be used as raw material for production of plant remedies at industrial scale.

  14. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins

    Directory of Open Access Journals (Sweden)

    Masami Suganuma

    2016-11-01

    Full Text Available Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (−-epigallocatechin gallate (EGCG in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young’s moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young’s moduli resulting in increased stiffness (large elasticity of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

  15. Catechins and Caffeine Inhibit Fat Accumulation in Mice through the Improvement of Hepatic Lipid Metabolism

    Directory of Open Access Journals (Sweden)

    Chikako Sugiura

    2012-01-01

    Full Text Available To elucidate the inhibiting mechanisms of fat accumulation by catechins, caffeine, and epigallocatechin gallate (EGCG, ICR mice were fed diets containing either 0.3% catechins or 0.1% EGCG and/or 0.05% caffeine for 4 weeks. After the feeding, intraperitoneal adipose tissues weights were significantly lower in the caffeine, catechins + caffeine, and EGCG + caffeine groups compared to controls. Hepatic fatty acid synthase (FAS activity in the catechins + caffeine group was significantly lower, and the activities of acyl-CoA oxidase (ACO and carnitine palmitoyltransferase-II (CPT-II were significantly higher, compared to the control group. However, these activities were not observed in the other groups. FAS mRNA expression levels in the catechins + caffeine group were significantly lower than in the control group. ACO and CPT-II mRNA levels were not different among all of the treatment groups. These findings indicate that the inhibitory effects of fat accumulation via a combination of catechins, EGCG, or caffeine were stronger collectively than by either catechins, EGCG, or caffeine alone. Moreover, it was demonstrated that the combination of catechins and caffeine induced inhibition of fat accumulation by suppression of fatty acid synthesis and upregulation of the enzymatic activities involved in β-oxidation of fatty acid in the liver, but this result was not observed by combination of EGCG and caffeine.

  16. Catechins and Caffeine Inhibit Fat Accumulation in Mice through the Improvement of Hepatic Lipid Metabolism.

    Science.gov (United States)

    Sugiura, Chikako; Nishimatsu, Shiho; Moriyama, Tatsuya; Ozasa, Sayaka; Kawada, Teruo; Sayama, Kazutoshi

    2012-01-01

    To elucidate the inhibiting mechanisms of fat accumulation by catechins, caffeine, and epigallocatechin gallate (EGCG), ICR mice were fed diets containing either 0.3% catechins or 0.1% EGCG and/or 0.05% caffeine for 4 weeks. After the feeding, intraperitoneal adipose tissues weights were significantly lower in the caffeine, catechins + caffeine, and EGCG + caffeine groups compared to controls. Hepatic fatty acid synthase (FAS) activity in the catechins + caffeine group was significantly lower, and the activities of acyl-CoA oxidase (ACO) and carnitine palmitoyltransferase-II (CPT-II) were significantly higher, compared to the control group. However, these activities were not observed in the other groups. FAS mRNA expression levels in the catechins + caffeine group were significantly lower than in the control group. ACO and CPT-II mRNA levels were not different among all of the treatment groups. These findings indicate that the inhibitory effects of fat accumulation via a combination of catechins, EGCG, or caffeine were stronger collectively than by either catechins, EGCG, or caffeine alone. Moreover, it was demonstrated that the combination of catechins and caffeine induced inhibition of fat accumulation by suppression of fatty acid synthesis and upregulation of the enzymatic activities involved in β-oxidation of fatty acid in the liver, but this result was not observed by combination of EGCG and caffeine.

  17. Supplementary catechins attenuate cooking-oil-fumes-induced oxidative stress in rat lung.

    Science.gov (United States)

    Yang, Chao-Huei; Lin, Chun-Yao; Yang, Joan-Hwa; Liou, Shaw-Yih; Li, Ping-Chia; Chien, Chiang-Ting

    2009-06-30

    Cooking-oil-fumes containing toxic components may induce reactive oxygen species (ROS) to oxidize macromolecules and lead to acute lung injury. Our previous study showed that a decaffineated green tea extract containing (+)-catechin, (-)-epicatechin, (+)-gallocatechin, (-)-epigallocatechin, (-)-epicatechin gallate, and (-)-epigallocatechin gallate can inhibit oxidation, inflammation, and apoptosis. We determined whether the catechins supplement may reduce cooking-oil-fumes-induced acute lung injury in rat. In the urethane-anesthetized Wistar rat subjected to 30-120 min of cooking-oil-fumes exposure, blood ROS significantly increased in the recovery stage. After 30-min cooking-oil-fumes exposure, the enhanced blood ROS level further increased in a time-dependent manner during the recovery stage (321 +/- 69 counts/10 s after 1 h, 540 +/- 89 counts/10 s after 2 h, and 873 +/- 112 counts/10 s after 4 h). Four hours after 30-min cooking-oil-fumes exposure, lung lavage neutrophils and ROS as well as lung tissue dityrosine and 4-hydroxy-2-nonenal increased significantly. Two weeks of catechins supplememnt significantly reduced the enhanced lavage ROS, lung dityrosine and 4-hydroxy-2-nonenal level. Cooking-oil-fumes-induced oxidative stress decreased lung Bcl-2/Bax ratio and HSP70 expression, but catechins treatment preserved the downregulation of Bcl-2/Bax ratio and HSP70 expression. We conclude that catechins supplement attenuates cooking-oil-fumes-induced acute lung injury via the preservation of oil-smoke induced downregulation of antioxidant, antiapoptosis, and chaperone protein expression.

  18. Biophysical Approach to Mechanisms of Cancer Prevention and Treatment with Green Tea Catechins.

    Science.gov (United States)

    Suganuma, Masami; Takahashi, Atsushi; Watanabe, Tatsuro; Iida, Keisuke; Matsuzaki, Takahisa; Yoshikawa, Hiroshi Y; Fujiki, Hirota

    2016-11-18

    Green tea catechin and green tea extract are now recognized as non-toxic cancer preventives for humans. We first review our brief historical development of green tea cancer prevention. Based on exciting evidence that green tea catechin, (-)-epigallocatechin gallate (EGCG) in drinking water inhibited lung metastasis of B16 melanoma cells, we and other researchers have studied the inhibitory mechanisms of metastasis with green tea catechins using biomechanical tools, atomic force microscopy (AFM) and microfluidic optical stretcher. Specifically, determination of biophysical properties of cancer cells, low cell stiffness, and high deformability in relation to migration, along with biophysical effects, were studied by treatment with green tea catechins. The study with AFM revealed that low average values of Young's moduli, indicating low cell stiffness, are closely associated with strong potential of cell migration and metastasis for various cancer cells. It is important to note that treatments with EGCG and green tea extract elevated the average values of Young's moduli resulting in increased stiffness (large elasticity) of melanomas and various cancer cells. We discuss here the biophysical basis of multifunctions of green tea catechins and green tea extract leading to beneficial effects for cancer prevention and treatment.

  19. Differentiation of green tea samples by chiral CD-MEKC analysis of catechins content.

    Science.gov (United States)

    Gotti, Roberto; Furlanetto, Sandra; Lanteri, Silvia; Olmo, Stefano; Ragaini, Alessandro; Cavrini, Vanni

    2009-08-01

    A chiral CD-MEKC method, enantioselective for catechin and gallocatechin, was developed, validated and applied to the analysis of tea samples. The method was addressed to the fast and simultaneous quantitation of the most represented and biologically important green tea catechins and methylxanthines. The CD-MEKC was based on SDS as surfactant (90 mM) and hydroxypropyl-beta-CD (25 mM) as chiral selector, under acidic conditions (25 mM borate-phosphate buffer, pH 2.5). The method was first applied to study the thermal epimerisation of epi-structured catechins, (-)-epicatechin and (-)-epigallocatechin, to non-epi-structured (-)-catechin and (-)-gallocatechin. The latter compounds, being non-native molecules, were for the first time regarded as useful phytomarkers of tea samples subjected to thermal treatment. The proposed method was applied to the analysis of more than twenty tea samples of different geographical origins (China, Japan, Ceylon), having undergone different storage conditions and manufacturing processes. Finally, factor analysis was used to visualise the useful information contained in the data set, showing that it was possible to distinguish tea samples on the basis of their different contents of native and non-native catechins.

  20. Flavonoids: biosynthesis, biological functions, and biotechnological applications

    Science.gov (United States)

    Falcone Ferreyra, María L.; Rius, Sebastián P.; Casati, Paula

    2012-01-01

    Flavonoids are widely distributed secondary metabolites with different metabolic functions in plants. The elucidation of the biosynthetic pathways, as well as their regulation by MYB, basic helix-loop-helix (bHLH), and WD40-type transcription factors, has allowed metabolic engineering of plants through the manipulation of the different final products with valuable applications. The present review describes the regulation of flavonoid biosynthesis, as well as the biological functions of flavonoids in plants, such as in defense against UV-B radiation and pathogen infection, nodulation, and pollen fertility. In addition, we discuss different strategies and achievements through the genetic engineering of flavonoid biosynthesis with implication in the industry and the combinatorial biosynthesis in microorganisms by the reconstruction of the pathway to obtain high amounts of specific compounds. PMID:23060891

  1. Flavonoids: Biosynthesis, Biological functions and Biotechnological applications

    Directory of Open Access Journals (Sweden)

    Maria Lorena eFalcone Ferreyra

    2012-09-01

    Full Text Available Flavonoids are widely distributed secondary metabolites with different metabolic functions in plants. The elucidation of the biosynthetic pathways, as well as their regulation by MYB, bHLH and WD40-type transcription factors, has allowed metabolic engineering of plants through the manipulation of the different final products with valuable applications. The present review describes the regulation of flavonoid biosynthesis, as well as the biological functions of flavonoids in plants, such as in defense against UV-B radiation and pathogen infection, nodulation, pollen fertility. In addition, we discuss different strategies and achievements through the genetic engineering of flavonoid biosynthesis with implication in the industry and the combinatorial biosynthesis in microorganisms by the reconstruction of the pathway to obtain high amounts of specific compounds.

  2. Structure-cytotoxicity relationships for dietary flavonoids

    DEFF Research Database (Denmark)

    Breinholt, V.; Dragsted, L.O.

    1998-01-01

    The cytotoxicity of a large series of dietary flavonoids was tested in a non-tumorigenic mouse and two human cancer cell lines, using the neutral red dye exclusion assay. All compounds tested exhibited a concentration-dependent cytotoxic action in the employed cell lines. The relative cytotoxicity...... of the flavonoids, however, Tvas found to vary greatly among the different cell Lines. With a few exceptions, the investigated flavonoids were more cytotoxic to the human cancer cell lines, than the mouse cell line. The differences in cytotoxicity were accounted for in part by differences in cellular uptake...... and metabolic capacity among the different cell types. In 3T3 cells fairly consistent structure-cytotoxicity relationships were found. The most cytotoxic structures tested in 3T3 cells were flavonoids with adjacent 3',4' hydroxy groups on the B-ring, such as luteolin, quercetin, myricetin, fisetin, eriodictyol...

  3. Some new external flavonoids from American ferns

    Energy Technology Data Exchange (ETDEWEB)

    Wollenweber, E.

    1979-01-01

    American gymnogrammoid ferns have been analysed for the flavonoid aglycones present in frond exudates. They are predominantly methylated chalcones, dihydrochalcones, flavones, and flavonols, occurring mostly as farinose deposit (''ceraceous indument''). This is the first report of external flavonoids on Pterozonium species; a chalcone has been identified. On Cheilanthes kaulfussii and Cheilanthes viscida traces of flavonoid aglycones are observed, dissolved in lipophilic exudate material. On Pellaea longimucronata a flavonol is found even on leaves which appear glaucous. 2',4',6'-Trihydroxychalcone is found for the second time in the plant kingdom on Adiantum sulphureum. Galangin-3,7-dimethylether is found as a new natural flavonol on Cheilanthes kaulfussii. In addition, samples of Pityrogramma chrysoconia and Pit. triangularis var. maxonii have been investigated. The results indicate chemotaxonomic implication of flavonoid patterns.

  4. Antioxidant flavonoids bind human serum albumin

    Science.gov (United States)

    Kanakis, C. D.; Tarantilis, P. A.; Polissiou, M. G.; Diamantoglou, S.; Tajmir-Riahi, H. A.

    2006-10-01

    Human serum albumin (HSA) is a principal extracellular protein with a high concentration in blood plasma and carrier for many drugs to different molecular targets. Flavonoids are powerful antioxidants and prevent DNA damage. The antioxidative protections are related to their binding modes to DNA duplex and complexation with free radicals in vivo. However, flavonoids are known to inhibit the activities of several enzymes such as calcium phospholipid-dependent protein kinase, tyrosine protein kinase from rat lung, phosphorylase kinase, phosphatidylinositol 3-kinase and DNA topoisomerases that exhibit the importance of flavonoid-protein interaction. This study was designed to examine the interaction of human serum albumin (HSA) with quercetin (que), kaempferol (kae) and delphinidin (del) in aqueous solution at physiological conditions, using constant protein concentration of 0.25 mM (final) and various drug contents of 1 μM-1 mM. FTIR and UV-vis spectroscopic methods were used to determine the polyphenolic binding mode, the binding constant and the effects of flavonoid complexation on protein secondary structure. The spectroscopic results showed that flavonoids are located along the polypeptide chains through H-bonding interactions with overall affinity constant of Kque = 1.4 × 10 4 M -1, Kkae = 2.6 × 10 5 M -1 and Kdel = 4.71 × 10 5 M -1. The protein secondary structure showed no alterations at low pigment concentration (1 μM), whereas at high flavonoid content (1 mM), major reduction of α-helix from 55% (free HSA) to 42-46% and increase of β-sheet from 15% (free HSA) to 17-19% and β-anti from 7% (free HSA) to 10-20% occurred in the flavonoid-HSA adducts. The major reduction of HSA α-helix is indicative of a partial protein unfolding upon flavonoid interaction.

  5. A New Flavonoid from Oxytropis kansuensis

    Institute of Scientific and Technical Information of China (English)

    Jun Xi LIU; Xin Yi HUANG; Duo Long DI; Sheng Xiang JIANG

    2006-01-01

    A new flavonoid 1 rhamnocitrin-3-O-(6"-feruloyl)-β-D-galactopyranoside-4'-O-β-D-glucospyranoside called kansuensisoside A together with a known flavonoid 2 (rhamnocitrin3-O-β-D-galactopyranoside-4'-O-β-D-glucospyranoside) were isolated from the extract of the whole plant of Oxytropis kansuensis Bunge. The structure of 1 was elucidated by spectroscopic methods including 2D-NMR techniques (COSY, HMQC, HMBC) and HR-ESIMS.

  6. Free sugar profile in cycads.

    Science.gov (United States)

    Marler, Thomas E; Lindström, Anders J

    2014-01-01

    The sugars fructose, glucose, maltose, and sucrose were quantified in seven tissues of Zamia muricata Willd. to determine their distribution throughout various organs of a model cycad species, and in lateral structural roots of 18 cycad species to determine the variation in sugar concentration and composition among species representing every cycad genus. Taproot and lateral structural roots contained more sugars than leaf, stem, female strobilus, or coralloid roots. For example, taproot sugar concentration was 6.4-fold greater than stem sugar concentration. The dominant root sugars were glucose and fructose, and the only detected stem sugar was sucrose. Sucrose also dominated the sugar profile for leaflet and coralloid root tissue, and fructose was the dominant sugar in female strobilus tissue. Maltose was a minor constituent of taproot, leaflet, and female strobilus tissue, but absent in other tissues. The concentration of total free sugars and each of the four sugars did not differ among genera or families. Stoichiometric relationships among the sugars, such as the quotient hexoses/disaccharides, differed among organs and families. Although anecdotal reports on cycad starch have been abundant due to its historical use as human food and the voluminous medical research invested into cycad neurotoxins, this is the first report on the sugar component of the non-structural carbohydrate profile of cycads. Fructose, glucose, and sucrose are abundant in cycad tissues, with their relative abundance highly contrasting among organs. Their importance as forms of carbon storage, messengers of information, or regulators of cycad metabolism have not been determined to date.

  7. The Maple Sugar Festival

    Science.gov (United States)

    Johnston, Basil

    1978-01-01

    Describing the Iroquoi's Maple Sugar Festival, this article details the symbolism of renewal, becoming, and regeneration celebrated by the Iroquoi as the sap from the maple trees begins to flow each year. The symbolic role of woman, the sweet sap itself, and man's fellow creatures are described. (JC)

  8. Flavonoids and oxidative stress in Drosophila melanogaster.

    Science.gov (United States)

    Sotibrán, América Nitxin Castañeda; Ordaz-Téllez, María Guadalupe; Rodríguez-Arnaiz, Rosario

    2011-11-27

    Flavonoids are a family of antioxidants that are widely represented in fruits, vegetables, dry legumes, and chocolate, as well as in popular beverages, such as red wine, coffee, and tea. The flavonoids chlorogenic acid, kaempferol, quercetin and quercetin 3β-d-glycoside were investigated for genotoxicity using the wing somatic mutation and recombination test (SMART). This test makes use of two recessive wing cell markers: multiple wing hairs (mwh) and flare (flr(3)), which are mutations located on the left arm of chromosome 3 of Drosophila melanogaster and are indicative of both mitotic recombination and various types of mutational events. In order to test the antioxidant capacities of the flavonoids, experiments were conducted with various combinations of oxidants and polyphenols. Oxidative stress was induced using hydrogen peroxide, the Fenton reaction and paraquat. Third-instar transheterozygous larvae were chronically treated for all experiments. The data obtained in this study showed that, at the concentrations tested, the flavonoids did not induce somatic mutations or recombination in D. melanogaster with the exception of quercetin, which proved to be genotoxic at only one concentration. The oxidants hydrogen peroxide and the Fenton reaction did not induce mutations in the wing somatic assay of D. melanogaster, while paraquat and combinations of flavonoids produced significant numbers of small single spots. Quercetin 3β-d-glycoside mixed with paraquat was shown to be desmutagenic. Combinations of the oxidants with the other flavonoids did not show any antioxidant activity.

  9. Green tea catechins reduced the glycaemic potential of bread: an in vitro digestibility study.

    Science.gov (United States)

    Goh, Royston; Gao, Jing; Ananingsih, Victoria K; Ranawana, Viren; Henry, Christiani Jeyakumar; Zhou, Weibiao

    2015-08-01

    Green tea catechins are potent inhibitors of enzymes for carbohydrate digestion. However, the potential of developing low glycaemic index bakery food using green tea extract has not been investigated. Results of this study showed that addition of green tea extract (GTE) at 0.45%, 1%, and 2% concentration levels significantly reduced the glycaemic potential of baked and steamed bread. The average retention levels of catechins in the baked and steamed bread were 75.3-89.5% and 81.4-99.3%, respectively. Bread fortified with 2% GTE showed a significantly lower level of glucose release during the first 90 min of pancreatic digestion as well as a lower content of rapidly digested starch (RDS) content. A significantly negative correlation was found between the catechin retention level and the RDS content of bread. The potential of transforming bread into a low GI food using GTE fortification was proven to be promising. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Green tea catechins: Proposed mechanisms of action in breast cancer focusing on the interplay between survival and apoptosis.

    Science.gov (United States)

    Yiannakopoulou, Eugenia Ch

    2014-02-01

    Recent data have shown strong chemopreventive and possibly cancer chemotherapeutic effects of green tea polyphenols against cancer. Despite advances in breast cancer treatment, mortality from breast cancer is still high. Undoubtedly novel treatment strategies are needed for chemoprevention of high risk women and for the treatment of receptor negative breast cancer. Green tea catechins have been shown to inhibit proliferation of breast cancer cells and to block carcinogenesis. This review attempts a critical presentation of the mechanisms of action of green tea catechins in breast cancer. Several mechanisms of action of green tea catechins in breast cancer have been proposed including modulation of extracellular signalling, induction of apoptosis through redox regulation, or through modulation of epigenetic alterations. A number of molecular targets of green tea catechins have been suggested i.e molecular chaperones, telomerase, apoptotic cascade. Although the molecular links among the proposed mechanisms of action of green tea catechins are often missing, it must be emphasized that all the proposed mechanisms indicate that green tea catechins inhibit growth and /or promote apoptosis. It would be interesting if future experimental trials could take into account that green tea catechins are multi-target agents and attempt to link every novel proposed target with the other already proposed targets of green tea catechins.

  11. Impact of fermentation, drying, roasting, and Dutch processing on epicatechin and catechin content of cacao beans and cocoa ingredients.

    Science.gov (United States)

    Payne, Mark J; Hurst, W Jeffrey; Miller, Kenneth B; Rank, Craig; Stuart, David A

    2010-10-13

    Low molecular weight flavan-3-ols are thought to be responsible, in part, for the cardiovascular benefits associated with cocoa powder and dark chocolate. The levels of epicatechin and catechin were determined in raw and conventionally fermented cacao beans and during conventional processing, which included drying, roasting, and Dutch (alkali) processing. Unripe cacao beans had 29% higher levels of epicatechin and the same level of catechin compared to fully ripe beans. Drying had minimal effect on the epicatechin and catechin levels. Substantial decreases (>80%) in catechin and epicatechin levels were observed in fermented versus unfermented beans. When both Ivory Coast and Papua New Guinea beans were subjected to roasting under controlled conditions, there was a distinct loss of epicatechin when bean temperatures exceeded 70 °C. When cacao beans were roasted to 120 °C, the catechin level in beans increased by 696% in unfermented beans, by 650% in Ivory Coast beans, and by 640% in Papua New Guinea fermented beans compared to the same unroasted beans. These results suggest that roasting in excess of 70 °C generates significant amounts of (-)-catechin, probably due to epimerization of (-)-epicatechin. Compared to natural cocoa powders, Dutch processing caused a loss in both epicatechin (up to 98%) and catechin (up to 80%). The epicatechin/catechin ratio is proposed as a useful and sensitive indicator for the processing history of cacao beans.

  12. Manage your blood sugar (image)

    Science.gov (United States)

    Checking your blood sugar levels often and writing down the results will tell you how well you are managing your diabetes so you ... possible. The best times to check your blood sugar are before meals and at bedtime. Your blood ...

  13. A Generic Multiple Reaction Monitoring Based Approach for Plant Flavonoids Profiling Using a Triple Quadrupole Linear Ion Trap Mass Spectrometry

    Science.gov (United States)

    Yan, Zhixiang; Lin, Ge; Ye, Yang; Wang, Yitao; Yan, Ru

    2014-06-01

    Flavonoids are one of the largest classes of plant secondary metabolites serving a variety of functions in plants and associating with a number of health benefits for humans. Typically, they are co-identified with many other secondary metabolites using untargeted metabolomics. The limited data quality of untargeted workflow calls for a shift from the breadth-first to the depth-first screening strategy when a specific biosynthetic pathway is focused on. Here we introduce a generic multiple reaction monitoring (MRM)-based approach for flavonoids profiling in plants using a hybrid triple quadrupole linear ion trap (QTrap) mass spectrometer. The approach includes four steps: (1) preliminary profiling of major aglycones by multiple ion monitoring triggered enhanced product ion scan (MIM-EPI); (2) glycones profiling by precursor ion triggered EPI scan (PI-EPI) of major aglycones; (3) comprehensive aglycones profiling by combining MIM-EPI and neutral loss triggered EPI scan (NL-EPI) of major glycone; (4) in-depth flavonoids profiling by MRM-EPI with elaborated MRM transitions. Particularly, incorporation of the NH3 loss and sugar elimination proved to be very informative and confirmative for flavonoids screening. This approach was applied for profiling flavonoids in Astragali radix ( Huangqi), a famous herb widely used for medicinal and nutritional purposes in China. In total, 421 flavonoids were tentatively characterized, among which less than 40 have been previously reported in this medicinal plant. This MRM-based approach provides versatility and sensitivity that required for flavonoids profiling in plants and serves as a useful tool for plant metabolomics.

  14. New Approaches for Effective Microwave Assisted Extraction of Caffeine and Catechins from Green Tea

    Directory of Open Access Journals (Sweden)

    Gönül SERDAR

    2016-01-01

    Full Text Available This study was designed to develop an effective microwave assisted extraction (MAE method for extraction of caffeine and catechins from green tea samples. A series of solvents (water, ethanol:water mixture or citric acid:water mixture were used for extraction of green tea samples (fresh, frozen or dried collected in three collection periods (first, second and third collection periods. Tea samples were extracted using water in a close microwave system under the certain extraction conditions. Extraction was carried out under a controlled 600 W microwave power at 80 oC temperature for 4 min irradiation time. Alternative to water, an ethanol-water mixture (1:1 or a citric acid-water (1:1 mixture was used as extracting solvent under the same conditions. After MAE crude aqueous extract was partitioned first with chloroform to separate caffeine then ethyl acetate for catechins.  Both caffeine and catechin extraction was quite successful with microwave assisted system employing only 4 minutes treatment. The highest caffeine yield was obtained in the second collection period using frozen green tea samples and ethanol-water as extracting solvent. The yield of catechin extracts was between 0.84-3.96% depending on the solvent system used for extraction. Ethanol-water mixture seems to be appropriate for effective extraction in the basis of extract yields. However, HPLC results showed that individual catechin content of each extraction is more important criteria for the evaluation of most effective extraction medium rather than the mass of the extract.  Using citric acid as extracting solvent in MAE seem to be more fruitful providing 100% catechin mixture with the highest EGCG content. 

  15. Mechanism of Creaming Down Based on Chemical Characterization of a Complex of Caffeine and Tea Catechins.

    Science.gov (United States)

    Ishizu, Takashi; Tsutsumi, Hiroyuki; Sato, Takashi

    2016-01-01

    The component of a precipitate resulting from creaming down, which was made from caffeine and a catechin mixture, was determined by an integrated value of H2 proton signals of tea catechins in the quantitative (1)H-NMR spectrum. The results showed that gallate-type catechins formed a precipitate by creaming down more predominantly than non-gallate-type catechins. X-ray crystallographic analysis showed that the gallate-type catechin (-)-epigallocatechin-3-O-gallate (EGCg), (-)-epicatechin-3-O-gallate (ECg) formed 2 : 2 and 2 : 4 complexes with caffeine, respectively, and the non-gallate-type catechin (-)-epicatechin (EC) and caffeine formed a 1 : 1 complex. The 2 : 2, 2 : 4 complexes of caffeine and EGCg, ECg formed a hydrophobic space with three aromatic A, B, and B' rings of two EGCg, ECg molecules, and one caffeine molecule was captured in this hydrophobic space. However, no such hydrophobic space in the 1 : 1 complex of caffeine and EC formed. It was thought that the hydrophobicity of the 2 : 2, 2 : 4 complexes of caffeine and EGCg, ECg was stronger than that of the 1 : 1 complex of caffeine and EC, with the result that the 2 : 2, 2 : 4 complexes of caffeine and EGCg, ECg precipitated by creaming down more predominantly than the 1 : 1 complex of caffeine and EC in an aqueous solution. Furthermore, the molecular capture of various heterocyclic compounds by formation of the 2 : 2 complex of EGCg from the aqueous solution was investigated using the quantitative (1)H-NMR spectrum.

  16. Anti-Trypanosoma cruzi activity of green tea (Camellia sinensis) catechins.

    Science.gov (United States)

    Paveto, Cristina; Güida, María C; Esteva, Mónica I; Martino, Virginia; Coussio, Jorge; Flawiá, Mirtha M; Torres, Héctor N

    2004-01-01

    The trypanocidal action of green tea catechins against two different developmental stages of Trypanosoma cruzi is reported for the first time. This activity was assayed with the nonproliferative bloodstream trypomastigote and with the intracellular replicative amastigote parasite forms. An ethyl acetate fraction from Camellia sinensis green tea leaves, which contains most of the polyphenolic compounds and the maximal trypanocidal activity, was obtained by fractionation of the aqueous extract with organic solvents. The active compounds present in this extract were further purified by LH-20 column chromatography and were identified by high-performance liquid chromatography analysis with a photo diode array detector and gas chromatography coupled to mass spectroscopy. The following flavan-3-ols derivatives, known as catechins, were identified: catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate. The purified compounds lysed more than 50% of the parasites present in the blood of infected BALB/c mice at concentrations as low as 0.12 to 85 pM. The most active compounds were gallocatechin gallate and epigallocatechin gallate, with minimal bactericidal concentrations that inhibited 50% of isolates tested of 0.12 and 0.53 pM, respectively. The number of amastigotes in infected Vero cells decreased by 50% in the presence of each of these compounds at 100 nM. The effects of the catechins on the recombinant T. cruzi arginine kinase, a key enzyme in the energy metabolism of the parasite, were assayed. The activity of this enzyme was inhibited by about 50% by nanomolar concentrations of catechin gallate or gallocatechin gallate, whereas the other members of the group were less effective. On the basis of these results, we suggest that these compounds could be used to sterilize blood and, eventually, as therapeutic agents for Chagas' disease.

  17. Sugar Beet (Beta vulgaris L.)

    OpenAIRE

    Kagami, Hiroyo; Kurata, Masayuki; Matsuhira, Hiroaki; Taguchi, Kazunori; Mikami, Tetsuo; Tamagake, Hideto; Kubo, Tomohiko

    2014-01-01

    Creating transgenic plants is invaluable for the genetic analysis of sugar beet and will be increasingly important as sugar beet genomic technologies progress. A protocol for Agrobacterium-mediated transformation of sugar beet is described in this chapter. Our protocol is optimized for a sugar beet genotype that performs exceptionally well in tissue culture, including the steps of dedifferentiation, callus proliferation, and regeneration. Because of the infrequent occurrence of such a genotyp...

  18. Quantification of catechins and caffeine from green tea (Camellia sinensis infusions, extract, and ready-to-drink beverages

    Directory of Open Access Journals (Sweden)

    Rafaela Macedo Mendes De Oliveira

    2012-03-01

    Full Text Available This study aimed to quantify the levels of catechins and caffeine in various forms of presentation of green tea: infusion tea bags, extract, and ready-to-drink beverage and, based on their content, identify the most suitable for consumption. High Performance Liquid Chromatography (HPLC analytical method was used for the quantification of catechins and caffeine. The tea bags had the highest concentration of total catechins with 5 to 9.5% followed by the extract with 3.64 to 4.88%, and ready-to-drink green tea beverage showed low levels of catechins, from 0.14 to 0.26%. As for caffeine content, green tea extract had higher concentration (1.96 to 3.54% compared to the tea bags (1.39 to 1.57%. Tea bags were found the most suitable for consumption because it contains higher amounts of catechins and smaller amounts of caffeine.

  19. Role of catechins in the antioxidant capacity of an active film containing green tea, green coffee, and grapefruit extracts.

    Science.gov (United States)

    Colon, M; Nerin, C

    2012-10-03

    The oxygen radical absorbance capacity (ORAC) method was used to characterize the antioxidant capacity of natural extracts of green tea, green coffee, and grapefruit. These natural extracts were incorporated into a plastic film layer, which was subsequently subjected to a free radical gas stream in order to determine the antioxidant capacity directly in the active film. The green tea extract (GTE) afforded the strongest antioxidant activity. To identify the active compounds in the extract, concentration of the diverse catechins in samples were determined by HPLC-UV analysis. The results showed that the content of catechins in the GTE is around 77% (w/w), the major components being (-)-epigallocatechin gallate, (-)-epicatechin gallate, and (-)-epicatechin. A variation in the concentration profile of catechins was detected during the oxidation process. The chromatographic study demonstrated that (-)-gallocatechin, (-)- epigallocatechin, (+)-catechin, and (-)-catechin gallate exhibited the most radical scavenging.

  20. Analysis of some selected catechins and caffeine in green tea by high performance liquid chromatography.

    Science.gov (United States)

    El-Shahawi, M S; Hamza, A; Bahaffi, S O; Al-Sibaai, A A; Abduljabbar, T N

    2012-10-15

    Green tea seems to have a positive impact on health due to the catechins-found as flavanols. Thus, the present study was aimed to develop a low cost reversed phase high performance liquid chromatographic (HPLC) method for simultaneous determination of flavanol contents, namely catechin (C), epicatechin (EC), epigallocatechin (EGC), epicatechin 3-gallate (ECG) and epigallocatechin 3-gallate (EGCG) and caffeine in 29 commercial green tea samples available in a Saudi Arabian local market. A C-18 reversed-phase column, acetonitrile-trifluoroacetic acid as a mobile phase, coupled with UV detector at 205 nm, was successfully used for precise analysis of the tested analytes in boiled water of digested tea leaves. The average values of N (No. of theoretical plates), HETP (height equivalent of theoretical plates) and R(s) (separation factor) (at 10 μg ml(-1) of the catechins EC, EGC, EGCG and ECG) were 2.6×10(3)±1.2×10(3), 1.7×10(-3)±4.7×10(-4) cm and 1.7±5.53×10(-2), respectively. The developed HPLC method demonstrated excellent performance, with low limits of detection (LOD) and quantification (LOQ) of the tested catechins of 0.004-0.05 μg ml(-1) and 0.01-0.17 μg ml(-1), respectively, and recovery percentages of 96-101%. The influence of infusion time (5-30 min) and temperature on the content of the flavanols was investigated by HPLC. After a 5 min infusion of the tea leaves, the average concentrations of caffeine, catechin, EC, EGC, ECG and EGCG were found to be in the ranges 0.086-2.23, 0.113-2.94, 0.58-10.22, 0.19-24.9, 0.22-13.9 and 1.01-43.3 mg g(-1), respectively. The contents of caffeine and catechins followed the sequence: EGCG>EGC>ECG>EC>C>caffeine. The method was applied satisfactorily for the analysis of (+)-catechin, even at trace and ultra trace concentrations of catechins. The method was rapid, accurate, reproducible and ideal for routine analysis.

  1. The Galloyl Catechins Contributing to Main Antioxidant Capacity of Tea Made from Camellia sinensis in China

    OpenAIRE

    Chunjian Zhao; Chunying Li; Shuaihua Liu; Lei Yang

    2014-01-01

    Total polyphenol content, catechins content, and antioxidant capacities of green, dark, oolong, and black teas made from Camellia sinensis in China were evaluated. The total polyphenol content of 20 samples of tea was in the range of 7.82–32.36%. Total catechins content was in the range of 4.34–24.27%. The antioxidant capacity of tea extract was determined by the oxygen radical absorbance capacity (ORAC) test and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging test. Total polyphen...

  2. Flavonoids, Flavonoid Subclasses, and Esophageal Cancer Risk: A Meta-Analysis of Epidemiologic Studies.

    Science.gov (United States)

    Cui, Lingling; Liu, Xinxin; Tian, Yalan; Xie, Chen; Li, Qianwen; Cui, Han; Sun, Changqing

    2016-06-08

    Flavonoids have been suggested to play a chemopreventive role in carcinogenesis. However, the epidemiologic studies assessing dietary intake of flavonoids and esophageal cancer risk have yielded inconsistent results. This study was designed to examine the association between flavonoids, each flavonoid subclass, and the risk of esophageal cancer with a meta-analysis approach. We searched for all relevant studies with a prospective cohort or case-control study design published from January 1990 to April 2016, using PUBMED, EMBASE, and Web of Science. Pooled odds ratios (ORs) were calculated using fixed or random-effect models. In total, seven articles including 2629 cases and 481,193 non-cases were selected for the meta-analysis. Comparing the highest-intake patients with the lowest-intake patients for total flavonoids and for each flavonoid subclass, we found that anthocyanidins (OR = 0.60, 95% CI: 0.49-0.74), flavanones (OR = 0.65, 95% CI: 0.49-0.86), and flavones (OR = 0.78, 95% CI 0.64-0.95) were inversely associated with the risk of esophageal cancer. However, total flavonoids showed marginal association with esophageal cancer risk (OR = 0.78, 95% CI: 0.59-1.04). In conclusion, our study suggested that dietary intake of total flavonoids, anthocyanidins, flavanones, and flavones might reduce the risk of esophageal cancer.

  3. Elevated plasma and urinary concentrations of green tea catechins associated with improved plasma lipid profile in healthy Japanese women.

    Science.gov (United States)

    Takechi, Ryusuke; Alfonso, Helman; Hiramatsu, Naoko; Ishisaka, Akari; Tanaka, Akira; Tan, La'Belle; Lee, Andy H

    2016-03-01

    This study investigated green tea catechins in plasma and urine and chronic disease biomarkers. We hypothesized that plasma and urinary concentration of green tea catechins are associated with cardiovascular disease and diabetes biomarkers. First void urine and fasting plasma samples were collected from 57 generally healthy females aged 38 to 73 years (mean, 52 ± 8 years) recruited in Himeji, Japan. The concentrations of plasma and urinary green tea catechins were determined by liquid chromatography coupled with mass tandem spectrometer. Low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, triglyceride, glucose, insulin, glycated hemoglobin, and C-reactive protein in plasma/serum samples were analyzed by a commercial diagnostic laboratory. Statistical associations were assessed using Spearman correlation coefficients. The results showed weak associations between plasma total catechin and triglyceride (r = -0.30) and LDL cholesterol (r = -0.28), whereas plasma (-)-epigallocatechin-3-gallate, (-)-epigallocatechin, (-)-epicatechin-3-gallate, and (-)-epicatechin exhibited weak to moderate associations with triglyceride or LDL cholesterol, but little associations with HDL cholesterol, body fat, and body mass index were evident. Urinary total catechin was weakly associated with triglyceride (r = -0.19) and LDL cholesterol (r = -0.15), whereas urinary (-)-epigallocatechin-3-gallate (r = -0.33), (-)-epigallocatechin (r = -0.23), and (-)-epicatechin-3-gallate (r = -0.33) had weak to moderate correlations with triglyceride and similarly with body fat and body mass index. Both plasma (r = -0.24) and urinary (r = -0.24) total catechin, as well as individual catechins, were weakly associated with glycated hemoglobin. Plasma total and individual catechins were weakly to moderately associated with C-reactive protein, but not the case for urinary catechins. In conclusion, we found weak to moderate associations between plasma and urinary green tea

  4. 75 FR 60715 - Domestic Sugar Program-FY 2010 and FY 2011 Cane Sugar and Beet Sugar Marketing Allotments and...

    Science.gov (United States)

    2010-10-01

    ... Commodity Credit Corporation Domestic Sugar Program--FY 2010 and FY 2011 Cane Sugar and Beet Sugar Marketing... 2010 (FY 2010) State sugar marketing allotments and company allocations to sugarcane and sugar beet processors. This applies to all domestic sugar marketed for human consumption in the United States from...

  5. Fundamental insights into conformational stability and orbital interactions of antioxidant (+)-catechin species and complexation of (+)-catechin with zinc(II) and oxovanadium(IV)

    Science.gov (United States)

    Yasarawan, Nuttawisit; Thipyapong, Khajadpai; Sirichai, Somsak; Ruangpornvisuti, Vithaya

    2013-09-01

    Conformational stability of (+)-catechin species in water has been examined with density functional theory, associated with the polarizable continuum model (PCM) of solvation. Factors such as electron delocalization, lone-pair electron donation and intramolecular hydrogen bonding substantially contribute to the conformational stabilization. Upon deprotonation, the HOMO and LUMO energies for (+)-catechin are both elevated; the energy gaps for the deprotonated species are narrower than the energy gap for the neutral species. The preferential deprotonation occurs at the C3'-, C5-, C7- and C4'-OH groups successively. The pKa value at 9.3 predicted for the most acidic OH group agrees well with previous experimental data; however the values are overestimated for the less acidic OH groups due to limitations of the PCM for charged solutes and/or complex nature of true deprotonation pathways. Formation of hydrogen radicals should be promoted at high pH values following the bond dissociation enthalpies. Complexation of (+)-catechin with either zinc(II) or oxovanadium(IV) is favored at the 1:1 metal-to-ligand (M:L) mole ratio, with the oxovanadium(IV) complex showing higher reaction preference. At M:L = 1:2, formation of two isomeric complexes are plausible for each type of metal ion. Effects of stoichiometry and isomerism on the computational spectral features of the possibly formed metal complexes have been described.

  6. Effects of stachyose on absorption and transportation of tea catechins in mice: possible role of Phase II metabolic enzymes and efflux transporters inhibition by stachyose

    Science.gov (United States)

    Li, Wenfeng; Lu, Yalong; Huang, Di; Han, Xiao; Yang, Xingbin

    2016-01-01

    Background Nutritional and absorption-promoting properties of stachyose combined with tea catechins (TC) have been revealed. However, the mechanism involved in non-digestible oligosaccharides-mediated enhancement of flavonoid absorption has largely remained elusive. Methods This study was designed to investigate the molecular mechanism of stachyose in enhancing absorption and transportation of TC in mice. Mice were orally pre-treated with stachyose (50, 250, and 500 mg/kg·bw) for 0–8 weeks, and 1 h before sacrifice, mice were treated with TC (250 mg/kg·bw). Results Gas chromatography-mass spectrometry analysis showed that serum concentrations of epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate were dose- and time-dependently elevated with stachyose pre-treatment in mice. Furthermore, pre-treatment with stachyose in mice reduced intestinal sulfotransferase and uridine diphosphate-glucuronosyltransferase levels by 3.3–43.2% and 23.9–30.4%, relative to control mice, respectively. Moreover, intestinal P-glycoprotein and multidrug resistance-associated protein-1 contents were decreased in mice by pre-administration of stachyose in dose- and time-dependent manner. Conclusions This is the first time to demonstrate that suppression of Phase II metabolic enzymes and efflux transporters of TC in the intestine can play a major role in increasing absorption of TC by stachyose feeding. PMID:27782875

  7. Effects of stachyose on absorption and transportation of tea catechins in mice: possible role of Phase II metabolic enzymes and efflux transporters inhibition by stachyose

    Directory of Open Access Journals (Sweden)

    Wenfeng Li

    2016-10-01

    Full Text Available Background: Nutritional and absorption-promoting properties of stachyose combined with tea catechins (TC have been revealed. However, the mechanism involved in non-digestible oligosaccharides-mediated enhancement of flavonoid absorption has largely remained elusive. Methods: This study was designed to investigate the molecular mechanism of stachyose in enhancing absorption and transportation of TC in mice. Mice were orally pre-treated with stachyose (50, 250, and 500 mg/kg·bw for 0–8 weeks, and 1 h before sacrifice, mice were treated with TC (250 mg/kg·bw. Results: Gas chromatography-mass spectrometry analysis showed that serum concentrations of epicatechin, epigallocatechin, epicatechin gallate, and epigallocatechin gallate were dose- and time-dependently elevated with stachyose pre-treatment in mice. Furthermore, pre-treatment with stachyose in mice reduced intestinal sulfotransferase and uridine diphosphate-glucuronosyltransferase levels by 3.3–43.2% and 23.9–30.4%, relative to control mice, respectively. Moreover, intestinal P-glycoprotein and multidrug resistance-associated protein-1 contents were decreased in mice by pre-administration of stachyose in dose- and time-dependent manner. Conclusions: This is the first time to demonstrate that suppression of Phase II metabolic enzymes and efflux transporters of TC in the intestine can play a major role in increasing absorption of TC by stachyose feeding.

  8. Starches, Sugars and Obesity

    Directory of Open Access Journals (Sweden)

    Erik E. J. G. Aller

    2011-03-01

    Full Text Available The rising prevalence of obesity, not only in adults but also in children and adolescents, is one of the most important public health problems in developed and developing countries. As one possible way to tackle obesity, a great interest has been stimulated in understanding the relationship between different types of dietary carbohydrate and appetite regulation, body weight and body composition. The present article reviews the conclusions from recent reviews and meta-analyses on the effects of different starches and sugars on body weight management and metabolic disturbances, and provides an update of the most recent studies on this topic. From the literature reviewed in this paper, potential beneficial effects of intake of starchy foods, especially those containing slowly-digestible and resistant starches, and potential detrimental effects of high intakes of fructose become apparent. This supports the intake of whole grains, legumes and vegetables, which contain more appropriate sources of carbohydrates associated with reduced risk of cardiovascular and other chronic diseases, rather than foods rich in sugars, especially in the form of sugar-sweetened beverages.

  9. Efficient procedure for isolating methylated catechins from green tea and effective simultaneous analysis of ten catechins, three purine alkaloids, and gallic acid in tea by high-performance liquid chromatography with diode array detection.

    Science.gov (United States)

    Hu, Bing; Wang, Lin; Zhou, Bei; Zhang, Xin; Sun, Yi; Ye, Hong; Zhao, Liyan; Hu, Qiuhui; Wang, Guoxiang; Zeng, Xiaoxiong

    2009-04-10

    Monomers of (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin 3-O-(3-O-methyl) gallate (EGCG3''Me) and (-)-3-O-methyl epicatechin gallate (ECG3'Me) (purity, >97%) were successfully prepared from extract of green tea by two-time separation with Toyopearl HW-40S column chromatography eluted by 80% ethanol. In addition, monomers of (-)-catechin (C), (-)-gallocatechin (GC), (-)-gallocatechin gallate (GCG), and (-)-catechin gallate (CG) (purity, >98%) were prepared from EC, EGC, EGCG, and ECG by heat-epimerization and semi-preparative HPLC chromatography. With the prepared catechin standards, an effective and simultaneous HPLC method for the analysis of gallic acid, tea catechins, and purine alkaloids in tea was developed in the present study. Using an ODS-100Z C(18) reversed-phase column, fourteen compounds were rapidly separated within 15min by a linear gradient elution of formic acid solution (pH 2.5) and methanol. A 2.5-7-fold reduction in HPLC analysis time was obtained from existing analytical methods (40-105min) for gallic acid, tea catechins including O-methylated catechins and epimers of epicatechins, as well as purine alkaloids. Detection limits were generally on the order of 0.1-1.0ng for most components at the applied wavelength of 280nm. Method replication generally resulted in intraday and interday peak area variation of catechins.

  10. Persimmon leaf flavonoid promotes brain ischemic tolerance**

    Institute of Scientific and Technical Information of China (English)

    Mingsan Miao; Xuexia Zhang; Ming Bai; Linan Wang

    2013-01-01

    Persimmon leaf flavonoid has been shown to enhance brain ischemic tolerance in mice, but its mechanism of action remains unclear. The bilateral common carotid arteries were occluded using a micro clip to block blood flow for 10 minutes. After 10 minutes of ischemic preconditioning, 200, 100, and 50 mg/kg persimmon leaf flavonoid or 20 mg/kg ginaton was intragastrical y administered per day for 5 days. At 1 hour after the final administration, ischemia/reperfusion models were estab-lished by blocking the middle cerebral artery for 2 hours. At 24 hours after model establishment, compared with cerebral ischemic rats without ischemic preconditioning or drug intervention, plasma endothelin, thrombomodulin and von Wil ebrand factor levels significantly decreased and intercel-lular adhesion molecule-1 expression markedly reduced in brain tissue from rats with ischemic pre-conditioning. Simultaneously, brain tissue injury reduced. Ischemic preconditioning combined with drug exposure noticeably improved the effects of the above-mentioned indices, and the effects of 200 mg/kg persimmon leaf flavonoid were similar to 20 mg/kg ginaton treatment. These results indicate that ischemic preconditioning produces tolerance to recurrent severe cerebral ischemia. However, persimmon leaf flavonoid can elevate ischemic tolerance by reducing inflammatory reactions and vascular endothelial injury. High-dose persimmon leaf flavonoid showed an identical effect to ginaton.

  11. Fermentation of various sugars and sugar substitutes by oral microorganisms

    Institute of Scientific and Technical Information of China (English)

    Boonyanit Thaweboon; Sroisiri Thaweboon; Doan Minh Tri

    2011-01-01

    Objective: To examine acid production of caries-associated strains of oral microorganisms and salivary microorganisms from sugar and sugar substitutes. Methods:Standard and clinical strains of Streptococcus mutans (S. mutans), Lactobacillus casei (L. casei) and Candida albicans were incubated in peptone-yeast-extract media containing 1% test sugar (sucrose, glucose, fructose) or sugar substitutes (xylitol, sorbitol, trehalulose and palatinose) at 37 ℃in 5% CO2 for 24-48 h. The pH of each culture was measured and microbial growth was determined as optical density at 660 nm. Paraffin-stimulated saliva collected from high caries-risk persons were added to media containing 10%test sugar or sugar substitutes. The pH of medium was measured at each time interval from 0-90 minutes. Results:All types of sugar and trehalulose could be fermented by all test microorganisms in pH lower than 5.5 except sucrose by standard strain of L. casei. All sugar and sugar substitutes supported growth of all organisms except xylitol for S. mutans. In the fermentation assay by salivary microorganisms, all sugar could be utilized and produced pH< 5.5 within 10 minutes of incubation and the pH drop was prolonged to until 90 minutes. Conversely, xylitol and palatinose were not fermented by microorganisms in saliva. Conclusions:All test microorganisms could ferment sucrose, glucose, fructose and trehalulose to pH lower than 5.5. Sugar alcohols and palatinose were not utilized well by organisms and may be used as sugar substitutes to reduce dental caries incidence. However, further studies particularly clinical investigations are required to evaluate the cariogenicity of these sugar substitutes.

  12. Radioprotective effects of flavonoids against to chromosomal damage: relation between the structure and activity

    Energy Technology Data Exchange (ETDEWEB)

    Alcaraz, M.; Acevedo, C.; Benavente-Garcia, O.; Castillo, J.; Vicente, V.; Canteras, M.

    2004-07-01

    Protective effects of grape (Vitis vinifera) seed (GSE), Citrus spp. fruits (CE) and olive Olea europaea L) leaf (OL) extracts, the flavonoids diosmin and rutin, widely used as pharmaceuticals, and diemthyl sulphoxide (DMSO) against chromosomal damage induced by X-rays and g radiation were determined by using two different micronucleus test for anti genotoxic activity. The quantitative distribution of several flavones-3-ols was determined using HPLC in a grape (Vitis vinifera), seed extract (GSE) and Olea european (OL) of four cultivars grown in the region of Murcia. Polymer>C4 units made up the largest group of procyanidins in the GSE (90,92%, expressed as HPLC% area). The antioxidant activity of GSE and other reference compounds was investigated by measuring theirs ability to scavenge the ABTS+ radical cation (TEAC). The most effective compounds were in order: GSE >rutin>(+)-catechin>OL>diosmina>ascorbic acid. The radioprotective effects of GSE and other reference compounds were determined by using the micronucleus test for anticlastogenic activity, any reduction of the frequency of micronucleated polychromatic erythrocytes (mnOCEs) being evaluated in the bone marrow of mouse exposed to X rays; and evaluating the reduction in the frequency of micronuclei in citokinesis-blocked cells of human lymphocytes exposed to g-rays. The most effective compounds were, in order: GSE>rutin>dimetylsufoxide (DMSO)>ascorbic acid>OL>6-n-propyl-2-thiouracil-6c (PTU)>disomin. The higher ABTS scavenging capacity and antigenotoxic activity of GSE can be explained, structurally, by the high number of conjugated structures between the catechol groups in the B-rings ant the 3-OH free groups of the polymeric polyphenolic skeleton and, in addition, by the stability of the aroxyl flavonoide radical generated in the above processes. (Author)

  13. Acclimation Changes of Flavonoids in Needles of Conifers during Heat and Drought Stress 2015

    Directory of Open Access Journals (Sweden)

    Walter Feucht

    2016-07-01

    Full Text Available The long-term harsh climate conditions in 2015 distorted already from June up to November in all study trees of Tsuga and Taxus the intracellular organization of the needles. Intimately involved in these repressive processes were the flavanols, a small subgroup of the flavonoids. They were not only deposited in vacuoles of conifer needles but also in the nuclei and chromosomes. Among the many flavonoids the small group of catechin derivatives and polymers named flavanols can exclusively be stained blue with DMACA (dimethylaminocinnamaldehyde. From mid-July onward, the vacuolar flavanols of the epidermal cell layers were gradually diminished as evidenced by decreasing blue staining of nuclei and vacuoles. Subsequently, in August also the large spongy mesophyll cells showed the flavanols decreasing progressively. Apparently, the antioxidant flavanols operate as oxygen radical scavengers. (ROS were used up during the harsh environmental stress conditions. Both, Tsuga and Taxus reacted in this way. However, it is quite surprising that in all study trees the palisade cells did not contain such vacuolar flavanols. Only these cells were in June the first to show a loss of chlorophyll from chloroplasts as well as an efflux of flavanols from the nuclei. Conversely, from September onward another group of phenols, the yellow-staining flavanols were newly formed in the palisade cells and later on also in the mesophyll cells. Obviously, they were assembled finally to stabilize finally the fragile cell sites. Summing up, the present study shows by cytological studies that the climatic conditions in 2015 produced the worst disturbance of subcellular structures observed since 2000 when our studies on nuclear phenols in needles of conifers were initiated.

  14. Polymeric proanthocyanidins: Interflavanoid linkage isomerism in (epicatechin-4)-(epicatechin-4)-catechin procyanidins

    Science.gov (United States)

    Richard W. Hemingway; L. Yeap Foo; L. J. Porter

    1981-01-01

    Procyanidin trimers have been isolated from a variety of plants,1-3 but their structures remain unresolved. We have now isolated three configurational isomers of (epicatechin-4)-(epicatechin-4)-catechin from Pinus taeda L. (loblolly pine) phloem which exhibit isomerism of the interflavanoid linkages.

  15. Green Tea Catechin Consumption Enhances Exercise-Induced Abdominal Fat Loss

    Science.gov (United States)

    Aim: This study evaluated the influence of a green tea catechin beverage on body composition and fat distribution in overweight and obese adults during exercised-induced weight loss. Methods: Participants (N=132) were randomly assigned to receive a 500 mL beverage containing approximately 625 mg of...

  16. Nutraceuticals for body-weight management: The role of green tea catechins.

    Science.gov (United States)

    Janssens, Pilou L H R; Hursel, Rick; Westerterp-Plantenga, Margriet S

    2016-08-01

    Green tea catechins mixed with caffeine have been proposed as adjuvants for maintaining or enhancing energy expenditure and for increasing fat oxidation, in the context of prevention and treatment of obesity. These catechins-caffeine mixtures seem to counteract the decrease in metabolic rate that occurs during weight loss. Their effects are of particular importance during weight maintenance after weight loss. Other metabolic targets may be fat absorption and the gut microbiota composition, but these effects still need further investigation in combination with weight loss. Limitations for the effects of green tea catechins are moderating factors such as genetic predisposition related to COMT-activity, habitual caffeine intake, and ingestion combined with dietary protein. In conclusion, a mixture of green tea catechins and caffeine has a beneficial effect on body-weight management, especially by sustained energy expenditure, fat oxidation, and preservation of fat free body-mass, after energy restriction induced body-weight loss, when taking the limitations into account. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Isolation and Purification of a Novel Long-chain Acyl Catechin from Lipophilic Tea Polyphenols

    Institute of Scientific and Technical Information of China (English)

    陈平; 杜琪珍

    2003-01-01

    Llpophilic tea polyphenols (LTP) was prepared by esterification of green tea polyphenols (GTP) with hexadecanoyl chloride. A novel long-chaln acyl catechin was isolated and purified from LTP by high-speed countercurrent chromatography (HSCCC).Its molecular structure was elucidated as epigallocatechin-3-O-gallate-4'-O-hexadecanate by elemental analysis, IR, MS and 1H NMR spectra.

  18. Role of Catechin Quinones in the Induction of EpRE-Mediated Gene Expression

    NARCIS (Netherlands)

    Muzolf-Panek, M.; Gliszczynska-Swiglo, A.; Haan, de L.H.J.; Aarts, J.M.M.J.G.; Szymusiak, H.; Vervoort, J.J.M.; Tyrakowska, B.; Rietjens, I.M.C.M.

    2008-01-01

    In the present study, the ability of green tea catechins to induce electrophile-responsive element (EpRE)-mediated gene expression and the role of their quinones in the mechanism of this induction were investigated. To this end, Hepa1c1c7 mouse hepatoma cells were used, stably transfected with a luc

  19. Green tea extract containing a highly absorbent catechin prevents diet-induced lipid metabolism disorder.

    Science.gov (United States)

    Suzuki, Takashi; Kumazoe, Motofumi; Kim, Yoonhee; Yamashita, Shuya; Nakahara, Kanami; Tsukamoto, Shuntaro; Sasaki, Masako; Hagihara, Takatoki; Tsurudome, Yukari; Huang, Yuhui; Maeda-Yamamoto, Mari; Shinoda, Yuki; Yamaguchi, Wataru; Yamada, Koji; Tachibana, Hirofumi

    2013-09-25

    We investigated the effects of extracts of Benifuuki (a tea cultivar that contains methylated catechins such as epigallocatechin-3-O-(3-O-methyl) gallate (EGCG3"Me)) in mice fed a high-fat/high-sucrose (HF/HS) diet. This tea cultivar was then compared with an extract of Yabukita (a popular tea cultivar that lacks methylated catechins). For 6 weeks, C57BL/6J mice were fed either HF/HS diet with or without tea extracts from tea cultivars, which contained almost identical ingredients except for methylated catechins (i.e., Yabukita (0.2% and 1%) or Benifuuki (0.2% and 1%) extract powders). Supplementation with Benifuuki 0.2% markedly lowered plasma levels of TG and NEFAs compared with mice supplemented with Yabukita 0.2%. The diet containing Benifuuki 1% decreased adipose tissue weights, liver TG, and expression of lipogenic genes in the liver. These results suggested that Benifuuki had much greater lipid-lowering effects than Yabukita. Taken together, these data suggest that methylated catechins direct the strong lipid-lowering activity of Benifuuki.

  20. UHPLC determination of catechins for the quality control of green tea.

    Science.gov (United States)

    Naldi, Marina; Fiori, Jessica; Gotti, Roberto; Périat, Aurélie; Veuthey, Jean-Luc; Guillarme, Davy; Andrisano, Vincenza

    2014-01-01

    An ultra-high performance liquid chromatography (UHPLC) with UV detection method was developed for the fast quantitation of the most represented and biologically important green tea catechins and caffeine. UHPLC system was equipped with C18 analytical column (50mm×2.1mm, 1.8μm), utilizing a mobile phase composed of pH 2.5 triethanolamine phosphate buffer (0.1M) and acetonitrile in a gradient elution mode; under these conditions six major catechins and caffeine were separated in a 3min run. The method was fully validated in terms of precision, detection and quantification limits, linearity, accuracy, and it was applied to the identification and quantification of catechins and caffeine present in green tea infusions. In particular, commercially available green tea leaves samples of different geographical origin (Sencha, Ceylon Green and Lung Ching) were used for infusion preparations (water at 85°C for 15min). The selectivity of the developed UHPLC method was confirmed by comparison with UHPLC-MS/MS analysis. The recovery of the main six catechins and caffeine on the three analyzed commercial tea samples ranged from 94 to 108% (n=3). Limits of detection (LOD) were comprised in the range 0.1-0.4μgmL(-1). An orthogonal micellar electrokinetic (MEKC) method was applied for comparative purposes on selectivity and quantitative data. The combined use of the results obtained by the two techniques allowed for a fast confirmation on quantitative characterization of commercial samples.

  1. Extract of lotus leaf ( Nelumbo nucifera ) and its active constituent catechin with insulin secretagogue activity.

    Science.gov (United States)

    Huang, Chun Fa; Chen, Ya Wen; Yang, Ching Yao; Lin, Hui Yi; Way, Tzong Der; Chiang, Wenchang; Liu, Shing Hwa

    2011-02-23

    The effect of lotus leaf ( Nelumbo nucifera Gaertn.) on diabetes is unclear. We hypothesized that lotus leaf can regulate insulin secretion and blood glucose levels. The in vitro and in vivo effects of lotus leaf methanolic extract (NNE) on insulin secretion and hyperglycemia were investigated. NNE increased insulin secretion from β cells (HIT-T15) and human islets. NNE enhanced the intracellular calcium levels in β cells. NNE could also enhance phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2 and protein kinase C (PKC), which could be reversed by a PKC inhibitor. The in vivo studies showed that NNE possesses the ability to regulate blood glucose levels in fasted normal mice and high-fat-diet-induced diabetic mice. Furthermore, the in vitro and in vivo effects of the active constituents of NNE, quercetin, and catechin, on glucose-induced insulin secretion and blood glucose regulation were evaluated. Quercetin did not affect insulin secretion, but catechin significantly and dose-dependently enhanced insulin secretion. Orally administered catechin significantly reversed the glucose intolerance in high-fat-diet-induced diabetic mice. These findings suggest that NNE and its active constituent catechin are useful in the control of hyperglycemia in non-insulin-dependent diabetes mellitus through their action as insulin secretagogues.

  2. Engineering the Production of Major Catechins by Escherichia coli Carrying Metabolite Genes of Camellia sinensis

    Directory of Open Access Journals (Sweden)

    Kabir Mustapha Umar

    2012-01-01

    Full Text Available A mimicked biosynthetic pathway of catechin metabolite genes from C. sinensis, consisting of flavanone 3 hydroxylase (F3H, dihydroflavonol reductase (DFR, and leucoanthocyanidin reductase (LCR, was designed and arranged in two sets of constructs: (a single promoter in front of F3H and ribosome-binding sequences both in front of DFR and LCR; (b three different promoters with each in the front of the three genes and ribosome-binding sequences at appropriate positions. Recombinant E. coli BL (DE3 harbouring the constructs were cultivated for 65 h at 26°C in M9 medium consisting of 40 g/L glucose, 1 mM IPTG, and 3 mM eriodictyol. Compounds produced were extracted in ethyl acetate in alkaline conditions after 1 h at room temperature and identified by HPLC. Two of the four major catechins, namely, (−-epicatechin (0.01  and (−-epicatechin gallate (0.36 mg/L, and two other types ((+-catechin hydrate (0.13 mg/L and (−-catechin gallate (0.04 mg/L were successfully produced.

  3. A Novel Phenylpropanoid-substituted Catechin Glycoside and a New Dihydrochalcone from Sarcandra glabra

    Institute of Scientific and Technical Information of China (English)

    Yuan LI; Dong Ming ZHANG; Shi Shan YU; Jian Bei LI; Yong Ming LUO

    2006-01-01

    A novel phenylpropanoid-substituted catechin glycoside glabraoside A 1 and a new dihydrochalcone 3'-(7″-allylphenyl)-2′,4′,4″-trihydroxy-6′-methoxydihydrochalcone 2 were isolated from the herbs of Sarcandra glabra. Their structures were elucidated on the basis of spectroscopic analyses and chiroptical methods.

  4. Estimating catechin concentrations of new shoots in the green tea field using ground-based hyperspectral image

    Science.gov (United States)

    Ryu, C. S.; Suguri, M.; Park, S. B.; Mikio, M.

    2013-10-01

    Hyperspectral camera was applied to establish the models of catechin concentration for green tea. The possibility of improvement for the models was checked by the multi-year models and the mutual prediction. ECg, EGCg and the ester catechin (ECg and EGCg) decreased with the growth but EC, EGC and the free catechin (EC and EGC) were changed by the covering. In partial least square regression (PLSR) models for each catechin, R2 (Relative Error for validation) was more than 0.785 (13.4%) for a single year data, 0.723 (13.3%) for two years data, and 0.756 (13.6%) for three years data except several catechins. It was possible to improve the precision and accuracy of models using the combination of catechin (free and ester type) or the combination of multi-year data. When each and each type of catechin model was predicted by the other year data, the accuracy of two years model improved comparing with it of a single year data. It means that the multi-year models might be more accurate than a single year models to predict the unknown data.

  5. Co-delivery of hydrophobic curcumin and hydrophilic catechin by a water-in-oil-in-water double emulsion.

    Science.gov (United States)

    Aditya, N P; Aditya, Sheetal; Yang, Hanjoo; Kim, Hye Won; Park, Sung Ook; Ko, Sanghoon

    2015-04-15

    Curcumin and catechin are naturally occurring phytochemicals with extreme sensitivity to oxidation and low bioavailability. We fabricated a water-in-oil-in-water (W/O/W) double emulsion encapsulating hydrophilic catechin and hydrophobic curcumin simultaneously. The co-loaded emulsion was fabricated using a two-step emulsification method, and its physicochemical properties were characterised. Volume-weighted mean size (d43) of emulsion droplets was ≈3.88 μm for blank emulsions, whereas it decreased to ≈2.8-3.0 μm for curcumin and/or catechin-loaded emulsions, which was attributed to their capacity to act as emulsifiers. High entrapment efficiency was observed for curcumin and/or catechin-loaded emulsions (88-97%). Encapsulation of catechin and curcumin within an emulsion increased their stability significantly in simulated gastrointestinal fluid, which resulted in a four-fold augmentation in their bioaccessibility compared to that of freely suspended curcumin and catechin solutions. Co-loading of curcumin and catechin did not have adverse effects on either compound's stability or bioaccessibility.

  6. Flavonoids as fruit and vegetable intake biomarkers

    DEFF Research Database (Denmark)

    Krogholm, Kirstine Suszkiewicz

    Most validation studies show that the food frequency questionnaire (FFQ) is rather low in precision and accuracy, and there is an ongoing debate regarding the applicability of such self-reported data with regard to diet-disease relationships. However, no other method has so far been able to replace...... of fruit and vegetable intakes. In Paper I, the urinary recovery of the 7 flavonoids in morning spot urine (i.e. all urine voids from midnight including the first morning void) was also found to respond to moderate increases in the intake of fruits and vegetables. However, the association was somewhat...... weaker than in 24h urine samples, indicating that the 24h urinary recovery of the 7 flavonoids is a stronger biomarker of the intake of fruit and vegetables than the urinary recovery of the 7 flavonoids in morning spot urine. In Paper II, the biokinetic profiles of some of the most important dietary...

  7. Flavonoids in Inflammatory Bowel Disease: A Review

    Science.gov (United States)

    Vezza, Teresa; Rodríguez-Nogales, Alba; Algieri, Francesca; Utrilla, Maria Pilar; Rodriguez-Cabezas, Maria Elena; Galvez, Julio

    2016-01-01

    Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the intestine that compromises the patients’ life quality and requires sustained pharmacological and surgical treatments. Since their etiology is not completely understood, non-fully-efficient drugs have been developed and those that have shown effectiveness are not devoid of quite important adverse effects that impair their long-term use. In this regard, a growing body of evidence confirms the health benefits of flavonoids. Flavonoids are compounds with low molecular weight that are widely distributed throughout the vegetable kingdom, including in edible plants. They may be of great utility in conditions of acute or chronic intestinal inflammation through different mechanisms including protection against oxidative stress, and preservation of epithelial barrier function and immunomodulatory properties in the gut. In this review we have revised the main flavonoid classes that have been assessed in different experimental models of colitis as well as the proposed mechanisms that support their beneficial effects. PMID:27070642

  8. Flavonoids in Inflammatory Bowel Disease: A Review

    Directory of Open Access Journals (Sweden)

    Teresa Vezza

    2016-04-01

    Full Text Available Inflammatory bowel disease (IBD is characterized by chronic inflammation of the intestine that compromises the patients’ life quality and requires sustained pharmacological and surgical treatments. Since their etiology is not completely understood, non-fully-efficient drugs have been developed and those that have shown effectiveness are not devoid of quite important adverse effects that impair their long-term use. In this regard, a growing body of evidence confirms the health benefits of flavonoids. Flavonoids are compounds with low molecular weight that are widely distributed throughout the vegetable kingdom, including in edible plants. They may be of great utility in conditions of acute or chronic intestinal inflammation through different mechanisms including protection against oxidative stress, and preservation of epithelial barrier function and immunomodulatory properties in the gut. In this review we have revised the main flavonoid classes that have been assessed in different experimental models of colitis as well as the proposed mechanisms that support their beneficial effects.

  9. Flavonoids from leaves of Mauritia flexuosa

    Directory of Open Access Journals (Sweden)

    Djalma M. de Oliveira

    2013-08-01

    Full Text Available The chromatographic fractionation of the Mauritia flexuosa L. f., Arecaceae, leaves extract, a plant known by the name of buriti palm tree, resulted in the isolation of six flavonoids: tricin-7-O-rutinoside, apigenin-6-C-arabinoside, 8-C-glucoside (isoschaftoside, kaempferol-3-O-rutinoside (nicotiflorine, quercetin-3-O-rutinoside (rutin, luteolin-8-C-glucoside (orientin and luteolin-6-C-glucoside (isoorientin. The flavonoids were found out and previously reported as constituents of the Arecaceae family plants, but the occurrence of C-glucoside flavonoids, in the species being analyzed, is described for the first time on this study. The structural elucidations of all of the isolated compounds were performed by means of the comparison of their spectral data (¹H and 13C NMR, UV and ESI-MS with those ones of the literature.

  10. Supercritical Fluid Extraction of Flavonoids from Dandelion

    Directory of Open Access Journals (Sweden)

    Wu Jun

    2014-01-01

    Full Text Available In this study, the total flavonoids from dandelion was extracted by supercritical CO2 and the total flavonoids content in the extract was investigated by the sodium nitrite-aluminum nitrate method with Rutin as a standard product. Single-factor experiments were carried out to map the effects of extraction pressure, temperature, time and entrainer amount on the yield of flavonoids. The orthogonal experiments on the optimum technology parameters demonstrated that the influence of the experimental conditions over the yield from high to low was: (a pressure, (b temperature, (c entrainer amount, (d time. The optimization result showed that under the conditions of 50°C, 35 MPa, 80 min and 4.0 mL/g entrainer amount, the yield of the preparative supercritical fluid extraction was 4.974%.

  11. Flavonoid composition of Juniperus oblonga Bieb.

    Science.gov (United States)

    Pisarev, D I; Novikov, O O; Novikova, M Yu; Zhilyakova, E T

    2011-04-01

    Juniperus oblonga Bieb is widely spread in the Caucasus Mountains, particularly in its eastern and southern regions. Diuretic effect of juniper berries is determined by the presence of volatile oils and polyphenol complex, particularly flavonoids. Flavonoids were extracted from raw material with 70% ethanol and then with ethyl acetate. Column chromatography of ethyl acetate fraction on polyamide yielded 5 compounds, which were identified on the basis of physicochemical constants of parent compounds and products of acid hydrolysis and alkaline degradation of aglycones and on the basis of UV-spectroscopy as apigenin, isoquercitrin, apigenin-7-glucoside, quercetin-3-rutinoside, and scutellarin-7-glucoside. Quantitative composition of flavonoid in equivalent to rutin concentration in Juniperus oblonga Bieb was 0.910±0.007% (UV-spectrophotometry data).

  12. In vitro human skin permeation and cutaneous metabolism of catechins from green tea extract and green tea extract-loaded chitosan microparticles.

    Science.gov (United States)

    Wisuitiprot, W; Somsiri, A; Ingkaninan, K; Waranuch, N

    2011-12-01

    Catechins are major antioxidants in green tea (Camellia sinensis or Camellia assamica), but because they do not permeate the skin well, the application of green tea in cosmetic products has so far been limited. This study aims to evaluate the cutaneous absorption of catechins from an extract of green tea and from a green tea extract-loaded chitosan microparticle. The catechin skin metabolism was also examined. The results suggest that chitosan microparticles significantly improve the ability of catechins to permeate skin. The cutaneous metabolism of the catechins significantly affected their permeation profiles. Epicatechin (EC) and epigallocatechin (EGC) penetrated the skin more than epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). The galloyl groups in EGCG and ECG were enzymatically hydrolysed to EGC and EC, respectively. Dehydroxylation of catechins was also observed. Chitosan microparticles effectively prevented enzymatic changes of the catechins; therefore, chitosan microparticles are here found to be the promising carriers for enhancing the skin permeation.

  13. Content Variation of Catechin Markers, Total Phenolics and Caffeine in Green Tea Dietary Supplements.

    Science.gov (United States)

    Abourashed, Ehab A; Roberson, Cindy Leslie A; Elsharkawy, Nancy

    2016-01-01

    Green tea (Camellia sinensis) preparations are among the top selling products in the United States dietary supplements market. Numerous manufacturers claim different levels of specific catechin markers in their products while many others use total phenolic concentration instead, or not at all. Limited quality control results have been published for green tea dietary supplements over the past seven years. Thus, the goal of this work was to correlate determined levels of phenolics, catechins, and caffeine with manufacturer label claims for selected dietary supplement products (26 total) purchased in the United States. The Folin-Ciocalteu (FC) method was used to determine the total phenolic content while reversed-phase (RP) HPLC was used to quantify the major catechins: epicatechin (EC), epigallocatechin (EGC), epicatechin gallate (ECG), epigallocatechin gallate (EGCG). The developed HPLC method was validated for accuracy and precision. It utilized a C8 column with gradient elution of acetonitrile in 0.1% aqueous formic acid over 11 min total run time. Peak detection was performed at 280 nm. Caffeine was also included in the HPLC method as another non-phenolic alkaloid marker commonly found in green tea. Both methods showed a good correlation between the content of catechins and polyphenolic compounds in the selected products. The ranges of total catechins and polyphenol concentrations were 3.8-70.2% and 3.6-95.8%, respectively, while that of caffeine was 0.8-11.2%. The selected products displayed a wide range of marker levels. A lack of conformity in disclosing the actual levels of marker compounds was also noticed in the labeling of many products.

  14. Ameliorative Effect of Green Tea Catechin Against Cadmium Chloride-Induced Testicular Toxicity in Mice.

    Science.gov (United States)

    Sharma, Priyanka; Goyal, Pradeep Kumar

    2015-01-01

    The present study was designed to evaluate the effect of green tea catechin (7500 µg/kg/animal/day) against cadmium-induced testicular dysfunctions and oxidative stress in the testes of mice. For this purpose, Swiss albino mice were divided into six groups: group I, negative control; group II, catechin-treated control; group III, cadmium chloride (CdCl2)-treated control; group IV, experimental group I; group V, experimental group II; and group VI, experimental group III. Animals from all of these groups were necropsied at various post-treatment intervals between 12 hours and 30 days for various biochemical alterations in the testes. CdCl2 intoxication resulted in a significant decline in testicular total proteins, cholesterol, and alkaline phosphatase, whereas acid phosphatase and lipid peroxidation exhibited a noticeable augmentation as compared to negative control. Catechin treatment effectively protected CdCl2-induced alterations in all such parameters throughout the experiment. Catechin was effective in reducing the CdCl2-induced augmentation of phase I (P450 and CYPB5) as well as phase II (DT-diaphorase and glutathione-S-transferase) enzymes in testes. Furthermore, CdCl2 intoxication was found to attenuate the antioxidant potential of testes, which was however augmented when supplemented with green tea extract. Compared to CdCl2-treated control mice, superoxide dismutase, glutathione peroxidase, glutathione, and catalase levels were significantly decreased in testes. Indeed, green tea catechin significantly increased testicular antioxidant enzymatic activities compared to those given CdCl2 alone. In conclusion, the use of green tea extract appeared to be beneficial to a great extent in inhibiting and restoring the testicular injuries induced by CdCl2 intoxication in mammals.

  15. Modified micellar electrokinetic chromatography in the analysis of catechins and xanthines in chocolate.

    Science.gov (United States)

    Gotti, Roberto; Fiori, Jessica; Mancini, Francesca; Cavrini, Vanni

    2004-10-01

    Modified micellar electrokinetic chromatography (MEKC) analysis of monomeric flavanols (catechin and epicatechin) and methylxanthines (caffeine and theobromine) in chocolate and cocoa was performed by using sodium dodecyl sulfate (SDS) as a principal component of the running buffer. Because of the reported poor stability of catechins in alkaline solutions, acidic conditions (pH 2.5) were chosen and consequently the electroosmotic flow (EOF) was significantly suppressed; this resulted in a fast anodic migration of the analytes partitioned into the SDS micelles. Under these conditions, variations of either pH value in acidic range or SDS concentration, showed to be not suitable to modulate the selectivity. To overcome this limit, use of additives to the SDS-based running buffer was successfully applied and three different systems were optimized for the separation of (+)-catechin, (-)-epicatechin, caffeine, and theobromine in chocolate and cocoa powder samples. In particular, two mixed micelle systems were applied; the first consisted of a mixture of SDS and 3-[(3-cholamidopropyl)dimethylammonio]-1-propansulfonate (CHAPS) with a composition of 90 mM and 10 mM, respectively; the second was SDS and taurodeoxycholic acid sodium salt (TDC) with a composition of 70 mM and 30 mM, respectively. A further MEKC approach was developed by addition of 10 mM hydroxypropyl-beta-cyclodextrin (HP-beta-CD) to the SDS solution (90 mM); it provided a useful cyclodextrin(CD)-modified MEKC. By applying the optimized conditions, different separation profiles of the flavanols and methylxanthines were obtained showing interesting potential of these combined systems; their integrated application showed to be useful for the identification of the low level of (+)-catechin in certain real samples. The CD-MEKC approach was validated and applied to the determination of catechins and methylxanthines in aqueous extracts from four different commercial chocolate types (black and milk) and two cocoa

  16. Free Sugar Profile in Cycads

    Directory of Open Access Journals (Sweden)

    Thomas Edward Marler

    2014-10-01

    Full Text Available The sugars fructose, glucose, maltose, and sucrose were quantified in seven tissues of Zamia muricata Willd. to determine their distribution throughout various organs of a model cycad species, and in lateral structural roots of 18 cycad species to determine the variation in sugar concentration and composition among species representing every cycad genus. Taproot and lateral structural roots contained more sugars than leaf, stem, female strobilus, or coralloid roots. For example, taproot sugar concentration was 6.4-fold greater than stem sugar concentration. The dominant root sugars were glucose and fructose, and the only detected stem sugar was sucrose. Sucrose also dominated the sugar profile for leaflet and coralloid root tissue, and fructose was the dominant sugar in female strobilus tissue. Maltose was a minor constituent of taproot, leaflet, and female strobilus tissue, but absent in other tissues. The concentration of total free sugars and each of the four sugars did not differ among genera or families. Stoichiometric relationships among the sugars, such as the quotient hexoses/disaccharides, differed among organs and families. Although anecdotal reports on cycad starch have been abundant due to its historical use as human food and the voluminous medical research invested into cycad neurotoxins, this is the first report on the sugar component of the non-structural carbohydrate profile of cycads. Fructose, glucose, and sucrose are abundant in cycad tissues, with their relative abundance highly contrasting among organs. Their importance as forms of carbon storage, messengers of information, or regulators of cycad metabolism have not been determined to date.

  17. ISOLATION AND IDENTIFICATION OF FLAVONOIDS FROM PROSOPIS JULIFLORA

    Directory of Open Access Journals (Sweden)

    KHANDELWAL PREETI

    2017-01-01

    Full Text Available Objective: The Flavonoids are remarkable and important secondary metabolites, found in plants. The present study was carried out to investigate the flavonoid content present in the leaves, stem, and pods of Prosopis juliflora. Methods: The established protocol of Subramanian & Nagarajan, 1969 was used for isolation of flavonoids. The structure of the isolated compounds was established on the basis of physical and chemical test and spectroscopic evidences (TLC, IR and GC- MS. Results: The study was revealed that the three types of flavonoids Quercetin, Kaempferol and Luteolin were found in Prosopis juliflora. Out of these three flavonoids, Quercetin was found as a major flavonoid. Kaempferol and luteolin were found as minor flavonoids. Conclusion: The present flavonoids may be responsible for various activities found in this plant, like- Antioxidant activity, anti-microbial activity etc.

  18. Strains for the production of flavonoids from glucose

    Energy Technology Data Exchange (ETDEWEB)

    Stephanopoulos, Gregory; Santos, Christine; Koffas, Mattheos

    2015-11-13

    The invention relates to the production of flavonoids and flavonoid precursors in cells through recombinant expression of tyrosine ammonia lyase (TAL), 4-coumarate:CoA ligase (4CL), chalcone synthase (CHS), and chalcone isomerase (CHI).

  19. Sap-Sugar Content of Grafted Sugar Maple Trees

    Science.gov (United States)

    Maurice E. Jr. Demeritt; Maurice E. Jr. Demeritt

    1985-01-01

    In March and April 1983, 289 and 196 young grafted sugar maple trees were tapped and evaluated for sap-sugar content. In April, sap was collected from taps both above and below the graft union. Diameter of all tapped trees at 18 inches above the ground was measured. Analysis of the data revealed that: (1) trees selected for high sugar yield cannot be reproduced by...

  20. Flavonoides e terpenoides de Croton muscicarpa (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    Milena B. Barreto

    2013-01-01

    Full Text Available A new sesquiterpene and twelve known compounds comprising eight flavonoids and four terpenoids, were isolated from the leaves, stems, roots and exudate of Croton muscicarpa Müll. Arg.. Their structures were identified as the terpenoids 6α-methoxy-cyperene, dammaradienol, squalene, acetyl aleuritolic acid and spathulenol, and as the flavonoids retusin, 3,7,4'-trimethoxy kaempferol, ombuine, pachipodol, kaempferol, casticin, 5-hydroxy-3,6,7,4'-tetramethoxyflavone and artemetin. All isolated compounds were characterized based on IR, MS, ¹H and 13C NMR, including 2D analyses (COSY, HSQC, HMBC, NOESY and comparison with data from the literature.

  1. Flavonoids and terpenoids from Croton muscicarpa (Euphorbiaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Milena B.; Gomes, Clerton L.; Freitas, Joao Vito B. de; Pinto, Francisco das Chagas L.; Silveira, Edilberto R.; Gramosa, Nilce V., E-mail: nilce@dqoi.ufc.br [Departamento de Quimica Organica e Inorganica, Centro de Ciencias, Universidade Federal do Ceara, Fortaleza (Brazil); Torres, Daniela S. Carneiro [Departamento de Ciencias Biologicas Jequie, Universidade Estadual do Sudoeste da Bahia, Jequie, BA (Brazil)

    2013-09-01

    A new sesquiterpene and twelve known compounds comprising eight flavonoids and four terpenoids, were isolated from the leaves, stems, roots and exudate of Croton muscicarpa Muell.. Arg.. Their structures were identified as the terpenoids 6{alpha}-methoxy-cyperene, dammaradienol, squalene, acetyl aleuritolic acid and spathulenol, and as the flavonoids retusin, 3,7,4'-trimethoxy kaempferol, ombuine, pachipodol, kaempferol, casticin, 5-hydroxy-3,6,7,4'-tetramethoxyflavone and artemetin. All isolated compounds were characterized based on IR, MS, {sup 1}H and {sup 13}C NMR, including 2D analyses (COSY, HSQC, HMBC, NOESY) and comparison with data from the literature. (author)

  2. Quantification of catechins and caffeine from green tea (Camellia sinensis) infusions, extract, and ready-to-drink beverages

    OpenAIRE

    Rafaela Macedo Mendes De Oliveira

    2012-01-01

    This study aimed to quantify the levels of catechins and caffeine in various forms of presentation of green tea: infusion tea bags, extract, and ready-to-drink beverage and, based on their content, identify the most suitable for consumption. High Performance Liquid Chromatography (HPLC) analytical method was used for the quantification of catechins and caffeine. The tea bags had the highest concentration of total catechins with 5 to 9.5% followed by the extract with 3.64 to 4.88%, and ready-t...

  3. Glutathione and the Antioxidant Potential of Binary Mixtures with Flavonoids: Synergisms and Antagonisms

    Directory of Open Access Journals (Sweden)

    Patrícia Valentão

    2013-07-01

    Full Text Available Polyphenols are able to trap free radicals, which contributes to their known antioxidant capacity. In plant extracts, these secondary metabolites may act in concert, in a way that their combined activities will be superior to their individual effects (synergistic interaction. Several polyphenols have demonstrated clear antioxidant properties in vitro, and many of their biological actions have been attributed to their intrinsic reducing capabilities. As so, the intake of these compounds at certain concentrations in the diet and/or supplementation may potentiate the activity of reduced form glutathione (GSH, thus better fighting oxidative stress. The aim of this work was to predict a structure-antioxidant activity relationship using different classes of flavonoids and to assess, for the first time, possible synergisms and antagonisms with GSH. For these purposes a screening microassay involving the scavenging of DPPH• was applied. In general, among the tested compounds, those lacking the catechol group in B ring showed antagonistic behaviour with GSH. Myricetin displayed additive effect, while quercetin, fisetin, luteolin, luteolin-7-O-glucoside, taxifolin and (+-catechin demonstrated synergistic actions. Furthermore, adducts formed at C2′ and C5′ of the B ring seem to be more important for the antioxidant capacity than adducts formed at C6 and C8 of the A ring.

  4. PENGARUH BLANCHING TERHADAP AKTIVITAS ANTIOKSIDAN, KADAR FENOL, FLAVONOID, DAN TANIN TERKONDENSASI KUNIR PUTIH (Curcuma mangga Val. Blanching Effects on Antioxidant Activity, Phenol, Flavonoid and Condensed Tannin Contents of White Saffron (Curcuma mang

    Directory of Open Access Journals (Sweden)

    Dwiyati Pujimulyani

    2012-05-01

    Full Text Available The purposes of this research were to examine antioxidant activity, total phenolic content (TPC, total flavonoid content(TFC, and condensed tannin content (CTC of blanced white saffron that were extracted with methanol : HCl=1000 :1.White saffron rhizomes were peeled, washed and blanched in the media of 0.0 5% and 0 % citric acid solution at 100 ºC for 5 and 10 minutes. �hite saffrons were evaluated antioxidant activity using 2-2-diphenyl-1-picrylhydrazyl (DPPH, TPC, TFC, and CTC. Blanched white saffron in the media of 0.05%, temperature 100 ºC for  5 minutes significantly increased the antioxidant  activity (from 87.38 to 90.90 % RSA, TPC (from 58.35 to 81.80 mg GAE/g, TFC (from12.82 to 24.69 mg QE/g, and CTC (from 6.10 to 10.59 mg CE/g compare to the non-blanched. The antioxidant activ-ity of blanched white saffron has significantly positive correlation with TPC, TFC, and CTC. ABSTRAK Tujuan penelitian ini adalah mengetahui pengaruh blanching terhadap aktivitas antioksidan kadar fenol total, flavonoid total dan kadar tanin terkondensasi kunir putih yang diekstrak dengan pelarut metanol : HCl = 1000 : 1.  Kunir putih dikupas, dicuci, dilakukan blanching dalam media asam sitrat 0,05 % dan 0 % (akuades, pada suhu 100 ºC selama5 dan 10 menit. Kunir putih diuji aktivitas antioksidan dengan metode 2-2-diphenyl-1-picrylhydrazyl (DPPH, kadarfenol total, flavonoid total dan tanin terkondensasi. Blanching dalam media asam sitrat 0,05 %, suhu 100 ºC selama5 menit dapat meningkatkan secara nyata aktivitas antioksidan dari 87,38 menjadi 90,90 % RSA (Radical Scaveng-ing Activity, kadar fenol total dari 58,35 menjadi 81,80 mg Ekivalen Asam Galat (EAG/g, flavonoid total dari 12,82menjadi 24,69 mg ekivalen kuersetin (EK/g dan tanin terkondensasi dari 6,10 menjadi 10,59 mg Ekivalen Catechin(EC/g dibanding kunir putih tanpa blanching. Aktivitas antioksidan kunir putih yang telah mengalami blanching dalammedia asam sitrat 0 % maupun 0,05 % berkorelasi

  5. Estrogenicity and metabolism of prenylated flavonoids and isoflavonoids

    NARCIS (Netherlands)

    Schans, van de M.G.M.

    2015-01-01

      Binding of (prenylated) flavonoids and isoflavonoids to the human estrogen receptors (hERs) might result in beneficial health effects in vivo. To understand structure-activity relationships of prenylated (iso)flavonoids towards the hERs, prenylated (iso)flavonoids were purified from extracts

  6. THE SYSTEMATIC AND EVOLUTIONARY SIGNIFICANCE OF EXUDATE FLAVONOIDS IN AEONIUM

    NARCIS (Netherlands)

    STEVENS, JF; HART, HT; WOLLENWEBER, E

    1995-01-01

    Leaf exudates of 32 species of Aeonium were examined for the presence of flavonoids. Thirty two flavonoids were detected in exudates of half of the species. The flavonoids were identified as methyl ethers of kaempferol, 6-hydroxykaempferol, quercetin, myricetin and scutellarein. The distribution of

  7. THE SYSTEMATIC AND EVOLUTIONARY SIGNIFICANCE OF EXUDATE FLAVONOIDS IN AEONIUM

    NARCIS (Netherlands)

    STEVENS, JF; HART, HT; WOLLENWEBER, E

    1995-01-01

    Leaf exudates of 32 species of Aeonium were examined for the presence of flavonoids. Thirty two flavonoids were detected in exudates of half of the species. The flavonoids were identified as methyl ethers of kaempferol, 6-hydroxykaempferol, quercetin, myricetin and scutellarein. The distribution of

  8. Comprehensive profiling and natural variation of flavonoids in rice

    Institute of Scientific and Technical Information of China (English)

    Xuekui Dong; Wei Chen; Wensheng Wang; Hongyan Zhang; Xianqing Liu; Jie Luo

    2014-01-01

    Flavonoids constitute a major group of plant phenolic compounds. While extensively studied in Arabidopsis, profiling and natural y occurring variation of these compounds in rice (Oryza sativa), the monocot model plant, are less reported. Using a col ection of rice germplasm, comprehensive profiling and natural variation of flavonoids were presented in this report. Application of a widely targeted metabolomics method facilitat-ed the simultaneous identification and quantification of more than 90 flavonoids using liquid chromatography tandem mass spectrometry (LC-MS/MS). Comparing flavonoid contents in various tissues during different developmental stages revealed tissue-specific accumulation of most flavonoids. Further investi-gation indicated that flavone mono-C-glycosides, malonylated flavonoid O-hexosides, and some flavonoid O-glycosides accu-mulated at significantly higher levels in indica than in japonica, while the opposite was observed for aromatic acylated flavone C-hexosyl-O-hexosides. In contrast to the highly differential accumulation between the two subspecies, relatively smal variations within subspecies were detected for most flavonoids. Besides, an association analysis between flavonoid accumulation and its biosynthetic gene sequence polymorphisms disclosed that natural variation of flavonoids was probably caused by sequence polymorphisms in the coding region of flavonoid biosynthetic genes. Our work paves the way for future dissection of biosynthesis and regulation of flavonoid pathway in rice.

  9. Effect of maturity on phenolics (phenolic acids and flavonoids) profile of strawberry cultivars and mulberry species from Pakistan.

    Science.gov (United States)

    Mahmood, Tahir; Anwar, Farooq; Abbas, Mateen; Saari, Nazamid

    2012-01-01

    In this study, we investigated how the extent of ripeness affects the yield of extract, total phenolics, total flavonoids, individual flavonols and phenolic acids in strawberry and mulberry cultivars from Pakistan. In strawberry, the yield of extract (%), total phenolics (TPC) and total flavonoids (TFC) ranged from 8.5-53.3%, 491-1884 mg gallic acid equivalents (GAE)/100 g DW and 83-327 mg catechin equivalents (CE)/100 g DW, respectively. For the different species of mulberry the yield of extract (%), total phenolics and total flavonoids of 6.9-54.0%, 201-2287 mg GAE/100 g DW and 110-1021 mg CE/100 g DW, respectively, varied significantly as fruit maturity progressed. The amounts of individual flavonols and phenolic acid in selected berry fruits were analyzed by RP-HPLC. Among the flavonols, the content of myricetin was found to be high in Morus alba (88 mg/100 g DW), the amount of quercetin as high in Morus laevigata (145 mg/100 g DW) while kaempferol was highest in the Korona strawberry (98 mg/100 g DW) at fully ripened stage. Of the six phenolic acids detected, p-hydroxybenzoic and p-coumaric acid were the major compounds in the strawberry. M. laevigata and M. nigra contained p-coumaric acid and vanillic acid while M. macroura and M. alba contained p-hydroxy-benzoic acid and chlorogenic acid as the major phenolic acids. Overall, a trend to an increase in the percentage of extraction yield, TPC, TFC, flavonols and phenolic acids was observed as maturity progressed from un-ripened to fully-ripened stages.

  10. Effect of Maturity on Phenolics (Phenolic Acids and Flavonoids Profile of Strawberry Cultivars and Mulberry Species from Pakistan

    Directory of Open Access Journals (Sweden)

    Tahir Mahmood

    2012-04-01

    Full Text Available In this study, we investigated how the extent of ripeness affects the yield of extract, total phenolics, total flavonoids, individual flavonols and phenolic acids in strawberry and mulberry cultivars from Pakistan. In strawberry, the yield of extract (%, total phenolics (TPC and total flavonoids (TFC ranged from 8.5–53.3%, 491–1884 mg gallic acid equivalents (GAE/100 g DW and 83–327 mg catechin equivalents (CE/100 g DW, respectively. For the different species of mulberry the yield of extract (%, total phenolics and total flavonoids of 6.9–54.0%, 201–2287 mg GAE/100 g DW and 110–1021 mg CE/100 g DW, respectively, varied significantly as fruit maturity progressed. The amounts of individual flavonols and phenolic acid in selected berry fruits were analyzed by RP-HPLC. Among the flavonols, the content of myricetin was found to be high in Morus alba (88 mg/100 g DW, the amount of quercetin as high in Morus laevigata (145 mg/100 g DW while kaempferol was highest in the Korona strawberry (98 mg/100 g DW at fully ripened stage. Of the six phenolic acids detected, p-hydroxybenzoic and p-coumaric acid were the major compounds in the strawberry. M. laevigata and M. nigra contained p-coumaric acid and vanillic acid while M. macroura and M. alba contained p-hydroxy-benzoic acid and chlorogenic acid as the major phenolic acids. Overall, a trend to an increase in the percentage of extraction yield, TPC, TFC, flavonols and phenolic acids was observed as maturity progressed from un-ripened to fully-ripened stages.

  11. Anti-arthritic Effects of Total Flavonoids from Juniperus sabina on Complete Freund's Adjuvant Induced Arthritis in Rats

    Science.gov (United States)

    Zhao, Jun; Liu, Tao; Xu, Fang; You, Shuping; Xu, Fang; Li, Chenyang; Gu, Zhengyi

    2016-01-01

    Context: Twigs and leaves of Juniperus sabina L. have been traditionally used as the medicinal herb in China for the treatment of many ailments including rheumatoid arthritis (RA). Aims: To confirm the therapeutic effect of total flavonoids from J. sabina (JSTF) on RA-induced by Complete Freund's Adjuvant (CFA) in rats. Settings and Design: Wistar rats (200 ± 20 g) were immunized by intradermal injection of 0.1 mL of CFA into the right hind metatarsal footpad. JSTF was administered orally at the dose of 125,250 and 500 mg/kg on 14 days after the induction of adjuvant arthritis. Tripterygium glycoside (20 mg/kg) was used as a positive control. Paw swelling, arthritic score, body weight loss, serum cytokines, inflammatory mediators, and histological change were measured. Results: We found that JSTF could ameliorate paw swelling of CFA rats, and significantly inhibit arthritic score (P Juniperus sabina L. have been traditionally used as the medicinal herb in China for the treatment of rheumatoid arthritisJSTF could ameliorate paw swelling of CFA rats, and significantly inhibit arthritic scoreHistopathological studies showed a marked decrease of synovial inflammatory infiltration and synovial lining hyperplasia in the joints of JSTF-treated animalsSix flavonoids were isolated and from JSTF including: Catechin, quercitrin, isoquercitrin, isoscutellarein 7-O-β-D-xylopyranoside, isoscutellarein 7-O-β-D-xylopyranose-(1 → 3)-α-L- rhamnoside, and rutin. Abbreviations used: JSTF: Total flavonoids from Juniperus sabina; CFA: Complete Freund's Adjuvant; TG: Tripterygium glycoside; TNF-α: Tumor necrosis factor alpha; IL-1β: Interleukin 1beta; IL-6: Interleukin 6; H and E: Hematoxylin and eosin. PMID:27601846

  12. Flavonoid-membrane Interactions: A Protective Role of Flavonoids at the Membrane Surface?

    Directory of Open Access Journals (Sweden)

    Patricia I. Oteiza

    2005-01-01

    Full Text Available Flavonoids can exert beneficial health effects through multiple mechanisms. In this paper, we address the important, although not fully understood, capacity of flavonoids to interact with cell membranes. The interactions of polyphenols with bilayers include: (a the partition of the more non-polar compounds in the hydrophobic interior of the membrane, and (b the formation of hydrogen bonds between the polar head groups of lipids and the more hydrophilic flavonoids at the membrane interface. The consequences of these interactions are discussed. The induction of changes in membrane physical properties can affect the rates of membrane lipid and protein oxidation. The partition of certain flavonoids in the hydrophobic core can result in a chain breaking antioxidant activity. We suggest that interactions of polyphenols at the surface of bilayers through hydrogen bonding, can act to reduce the access of deleterious molecules (i.e. oxidants, thus protecting the structure and function of membranes.

  13. Separation of flavonoids by means of solvent extraction; Yobai chushutsuho ni yoru flavonoid rui no bunri

    Energy Technology Data Exchange (ETDEWEB)

    Kitazaki, H.; Ishimaru, M. [Tsumura and Co., Tokyo (Japan); Inoue, K.; Nakamura, S. [Saga University, Saga (Japan). Faculty of Science and Engineering

    1997-03-10

    Some herb medicines may contain various flavonoids. The bioactivity of them has been attracted attention. In this paper, the separating purification method by solvent extraction was investigated. The extractant is di (ethylhexyl) amine, tributyl phosphate, N,N-dioctyl hexanamide, trioctylphosphine oxide (TOPO), and Cyanex 925. Flavonoids are considered to be separated based on the difference of solubility in an ethanol solution, the existence of a glycoside in flavonoids, and the number of hydroxyl groups or their bonding position. For example, flavone, flavonol, 7,8-dihydroxyflavone, baicalein, and baicalin are used as the representative substance of flavonoids. If a target substance is baicalin, this mixture is dissolved in an ethanol solution to eliminate insoluble matter such as flavonol. Next, flavone is extracted and eliminated by hexane. In the last step, the target baicalin is left in raffinate by TOPO or Cyanex 925. 3 refs., 7 figs., 1 tab.

  14. 76 FR 62339 - Domestic Sugar Program-2011-Crop Cane Sugar and Beet Sugar Marketing Allotments and Company...

    Science.gov (United States)

    2011-10-07

    ... Commodity Credit Corporation Domestic Sugar Program--2011-Crop Cane Sugar and Beet Sugar Marketing... Commodity Credit Corporation (CCC) is issuing this notice to publish the fiscal year (FY) 2012 State sugar marketing allotments and company allocations to sugarcane and sugar beet processors, which apply to all...

  15. A new flavonoid from Selaginella tamariscina

    Institute of Scientific and Technical Information of China (English)

    Jian Feng Liu; Kang Ping Xu; De Jian Jiang; Fu Shuang Li; Jian Shen; Ying Jun Zhou; Ping Sheng Xu; Bin Tan; Gui Shan Tan

    2009-01-01

    6-(2-Hydroxy-5-acetylphenyl)-apigenin (1),a new flavonoid with a phenyl substituent,was first isolated from Selaginella tamariscina.Its structure was elucidated on the basis of 1D and 2D NMR as well as ESI-HR-MS spectroscopic analysis.

  16. Structure-cytotoxicity relationships for dietary flavonoids

    DEFF Research Database (Denmark)

    Breinholt, V.; Dragsted, L.O.

    1998-01-01

    and metabolic capacity among the different cell types. In 3T3 cells fairly consistent structure-cytotoxicity relationships were found. The most cytotoxic structures tested in 3T3 cells were flavonoids with adjacent 3',4' hydroxy groups on the B-ring, such as luteolin, quercetin, myricetin, fisetin, eriodictyol...

  17. Flavonoids as Inhibitors of Human Butyrylcholinesterase Variants

    Directory of Open Access Journals (Sweden)

    Maja Katalinić

    2014-01-01

    Full Text Available The inhibition of butyrylcholinesterase (BChE, EC 3.1.1.8 appears to be of interest in treating diseases with symptoms of reduced neurotransmitter levels, such as Alzheimer’s disease. However, BCHE gene polymorphism should not be neglected in research since it could have an effect on the expected outcome. Several well-known cholinergic drugs (e.g. galantamine, huperzine and rivastigmine originating from plants, or synthesised as derivatives of plant compounds, have shown that herbs could serve as a source of novel target-directed compounds. We focused our research on flavonoids, biologically active polyphenolic compounds found in many plants and plant-derived products, as BChE inhibitors. All of the tested flavonoids: galangin, quercetin, fisetin and luteolin reversibly inhibited usual, atypical, and fluoride-resistant variants of human BChE. The inhibition potency increased in the following order, identically for all three BChE variants: luteolinflavonoids exists in view of BChE polymorphism. Our results suggested that flavonoids could assist the further development of new BChE-targeted drugs for treating symptoms of neurodegenerative diseases and dementia.

  18. Flavonoids protecting food and beverages against light.

    Science.gov (United States)

    Huvaere, Kevin; Skibsted, Leif H

    2015-01-01

    Flavonoids, which are ubiquitously present in the plant kingdom, preserve food and beverages at the parts per million level with minor perturbation of sensory impressions. Additionally, they are safe and possibly contribute positive health effects. Flavonoids should be further exploited for the protection of food and beverages against light-induced quality deterioration through: (1) direct absorption of photons as inner filters protecting sensitive food components; (2) deactivation of (triplet-)excited states of sensitisers like chlorophyll and riboflavin; (3) quenching of singlet oxygen from type II photosensitisation; and (iv) scavenging of radicals formed as reaction intermediates in type I photosensitisation. For absorption of light, combinations of flavonoids, as found in natural co-pigmentation, facilitate dissipation of photon energy to heat thus averting photodegradation. For protection against singlet oxygen and triplet sensitisers, chemical quenching gradually decreases efficiency hence the pathway to physical quenching should be optimised through product formulation. The feasibility of these protection strategies is further supported by kinetic data that are becoming available, allowing for calculation of threshold levels of flavonoids to prevent beer and dairy products from going off. On the other hand, increasing understanding of the interplay between light and matrix physicochemistry, for example the effect of aprotic microenvironments on phototautomerisation of compounds like quercetin, opens up for engineering better light-to-heat converting channels in processed food to eventually prevent quality loss.

  19. Two New Flavonoid Glycosides from Chrysanthemum morifolium

    Institute of Scientific and Technical Information of China (English)

    Jian ZHANG; An Wei DING; You Bin LI; Da Wei QIAN; Jin Ao DUAN; Zhi Qi YIN

    2006-01-01

    Two new flavonoid glycosides were isolated from the flowering heads of Chrysanthemum morifolium. Their structures were determined to be luteolin 4'-methoxy-7- O-(6"-O-acetyl)-β-D-glucopyranoside (1) and acacetin 7-O-(3"-O-acetyl)-β-D-glucopyranoside (2) by means of 1H and 13C NMR spectroscopic analysis, including 2D NMR technique.

  20. Absorption, bioavailability and metabolism of flavonoids

    NARCIS (Netherlands)

    Hollman, P.C.H.

    2004-01-01

    To unravel mechanisms of action of dietary flavonoids in their potential role in disease prevention, it is crucial to know the factors that determine their release from foods, their extent of absorption, and their fate in the organism. Research on absorption, metabolism, and bioavailability of flavo

  1. Functional screening of metagenome and genome libraries for detection of novel flavonoid-modifying enzymes.

    Science.gov (United States)

    Rabausch, U; Juergensen, J; Ilmberger, N; Böhnke, S; Fischer, S; Schubach, B; Schulte, M; Streit, W R

    2013-08-01

    The functional detection of novel enzymes other than hydrolases from metagenomes is limited since only a very few reliable screening procedures are available that allow the rapid screening of large clone libraries. For the discovery of flavonoid-modifying enzymes in genome and metagenome clone libraries, we have developed a new screening system based on high-performance thin-layer chromatography (HPTLC). This metagenome extract thin-layer chromatography analysis (META) allows the rapid detection of glycosyltransferase (GT) and also other flavonoid-modifying activities. The developed screening method is highly sensitive, and an amount of 4 ng of modified flavonoid molecules can be detected. This novel technology was validated against a control library of 1,920 fosmid clones generated from a single Bacillus cereus isolate and then used to analyze more than 38,000 clones derived from two different metagenomic preparations. Thereby we identified two novel UDP glycosyltransferase (UGT) genes. The metagenome-derived gtfC gene encoded a 52-kDa protein, and the deduced amino acid sequence was weakly similar to sequences of putative UGTs from Fibrisoma and Dyadobacter. GtfC mediated the transfer of different hexose moieties and exhibited high activities on flavones, flavonols, flavanones, and stilbenes and also accepted isoflavones and chalcones. From the control library we identified a novel macroside glycosyltransferase (MGT) with a calculated molecular mass of 46 kDa. The deduced amino acid sequence was highly similar to sequences of MGTs from Bacillus thuringiensis. Recombinant MgtB transferred the sugar residue from UDP-glucose effectively to flavones, flavonols, isoflavones, and flavanones. Moreover, MgtB exhibited high activity on larger flavonoid molecules such as tiliroside.

  2. Analysis of flavonoids and the flavonoid structural genes in brown fiber of upland cotton.

    Directory of Open Access Journals (Sweden)

    Hongjie Feng

    Full Text Available BACKGROUND: As a result of changing consumer preferences, cotton (Gossypium Hirsutum L. from varieties with naturally colored fibers is becoming increasingly sought after in the textile industry. The molecular mechanisms leading to colored fiber development are still largely unknown, although it is expected that the color is derived from flavanoids. EXPERIMENTAL DESIGN: Firstly, four key genes of the flavonoid biosynthetic pathway in cotton (GhC4H, GhCHS, GhF3'H, and GhF3'5'H were cloned and studied their expression profiles during the development of brown- and white cotton fibers by QRT-PCR. And then, the concentrations of four components of the flavonoid biosynthetic pathway, naringenin, quercetin, kaempferol and myricetin in brown- and white fibers were analyzed at different developmental stages by HPLC. RESULT: The predicted proteins of the four flavonoid structural genes corresponding to these genes exhibit strong sequence similarity to their counterparts in various plant species. Transcript levels for all four genes were considerably higher in developing brown fibers than in white fibers from a near isogenic line (NIL. The contents of four flavonoids (naringenin, quercetin, kaempferol and myricetin were significantly higher in brown than in white fibers and corresponding to the biosynthetic gene expression levels. CONCLUSIONS: Flavonoid structural gene expression and flavonoid metabolism are important in the development of pigmentation in brown cotton fibers.

  3. The effects of bathing in hot springs on the absorption of green tea catechin: a pilot study.

    Science.gov (United States)

    Hayasaka, Shinya; Goto, Yasuaki; Maeda-Yamamoto, Mari

    2013-11-01

    Japan is a major tea producing country, and green tea is known for its health benefits which are believed to be due to catechins. However, difficulties in maintaining an adequate amount of catechins in the blood have been reported. Another important health-promoting activity among the Japanese is bathing in hot springs. This pilot study examined whether the combined effects of green tea consumption and hot spring bathing improved absorption of green tea catechins. The study, with a comparative within-subject design involving two different intervention trials--green tea consumption with hot spring bathing and only green tea consumption--was conducted on 2 separate days. Plasma levels of catechin; (-)-epigallocatechin-3-O-gallate (EGCG) were analyzed from four volunteers. Plasma EGCG concentration was found to be higher for the combined trial of green tea consumption and hot spring bathing.

  4. Effect of moderate intakes of different tea catechins and caffeine on acute measures of energy metabolism under sedentary conditions

    DEFF Research Database (Denmark)

    Gregersen, N.T.; Bitz, C.; Krog-Mikkelsen, I.

    2009-01-01

    Green tea may stimulate energy metabolism; however, it is unclear if acute effects are caused by specific catechins, caffeine or their combination. The objective of the present study was to examine the separate and combined effects of different catechins and caffeine on energy expenditure (EE......) and fat oxidation over a single day. Fifteen healthy, normal-weight males received capsules containing placebo, caffeine alone (150mg), or caffeine plus a catechin mixture (600 mg) enriched in either epigallocatechin-3-gallate (EGCG), epigallocatechin or a mix of catechins, in a randomised cross......-over double-blinded design. On each test day EE, respiratory quotient (RQ) and substrate oxidation were measured under sedentary conditions in a respiratory chamber for 13.5h. We found no significant treatment effect on EE (P=0.20) or RQ (P=0.68). EGCG with caffeine insignificantly raised EE and fat oxidation...

  5. Green Tea Catechin Metabolites Exert Immunoregulatory Effects on CD4(+) T Cell and Natural Killer Cell Activities.

    Science.gov (United States)

    Kim, Yoon Hee; Won, Yeong-Seon; Yang, Xue; Kumazoe, Motofumi; Yamashita, Shuya; Hara, Aya; Takagaki, Akiko; Goto, Keiichi; Nanjo, Fumio; Tachibana, Hirofumi

    2016-05-11

    Tea catechins, such as (-)-epigallocatechin-3-O-gallate (EGCG), have been shown to effectively enhance immune activity and prevent cancer, although the underlying mechanism is unclear. Green tea catechins are instead converted to catechin metabolites in the intestine. Here, we show that these green tea catechin metabolites enhance CD4(+) T cell activity as well as natural killer (NK) cell activity. Our data suggest that the absence of a 4'-hydroxyl on this phenyl group (B ring) is important for the effect on immune activity. In particular, 5-(3',5'-dihydroxyphenyl)-γ-valerolactone (EGC-M5), a major metabolite of EGCG, not only increased the activity of CD4(+) T cells but also enhanced the cytotoxic activity of NK cells in vivo. These data suggest that EGC-M5 might show immunostimulatory activity.

  6. Simultaneous preparation of naturally abundant and rare catechins by tannase-mediated biotransformation combining high speed counter current chromatography.

    Science.gov (United States)

    Xia, Guobin; Hong, Shan; Liu, Songbai

    2014-05-15

    Simultaneous preparation of naturally rare catechins, EGC and EC, has been realized by tannase-mediated biotransformation combining high speed counter current chromatography. In addition, simultaneous preparation of the four catechins, EGCG, ECG, EGC, and EC in green tea extract has also been achieved by HSCCC under the normal phase and the reversed phase modes. The identity of the catechins was determined by HPLC-DAD-ESI-MS and quantification of the catechins was performed by HPLC-DAD. In a typical HSCCC separation, 27.2 mg 98.8% EGCG, 14.1 mg 94.7% EGC, and 9.3 mg 97.5% EC were obtained. This new method is efficient, time-saving and valuable for biological studies.

  7. The Role of Flavonoids on Oxidative Stress in Epilepsy

    Directory of Open Access Journals (Sweden)

    Tâmara Coimbra Diniz

    2015-01-01

    Full Text Available Backgrounds. Oxidative stress can result from excessive free-radical production and it is likely implicated as a possible mechanism involved in the initiation and progression of epileptogenesis. Flavonoids can protect the brain from oxidative stress. In the central nervous system (CNS several flavonoids bind to the benzodiazepine site on the GABAA-receptor resulting in anticonvulsive effects. Objective. This review provides an overview about the role of flavonoids in oxidative stress in epilepsy. The mechanism of action of flavonoids and its relation to the chemical structure is also discussed. Results/Conclusions. There is evidence that suggests that flavonoids have potential for neuroprotection in epilepsy.

  8. Allelopathic potential of catechins of the Tachigali myrmecophyla (Leguminosae); Potencial alelopatico de catequinas de Tachigali myrmecophyla (leguminosae)

    Energy Technology Data Exchange (ETDEWEB)

    Lobo, Livia T.; Castro, Kelly Christina Ferreira; Arruda, Mara Silvia P.; Silva, Milton N. da; Arruda, Alberto C.; Mueller, Adolfo Henrique; Arruda, Giselle Maria Skelding P.; Santos, Alberdan Silva [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Centro de Ciencias Exatas e Naturais. Dept. de Quimica]. E-mail: livia_lobo@yahoo.com.br; Souza Filho, Antonio Pedro da Silva [EMBRAPA Amazonia Oriental, Belem, PA (Brazil). Lab. de Agroindustria

    2008-07-01

    Two compounds, (+)-catechin and epicatechin, were isolated from leaves of T. myrmecophyla, using chromatographic techniques. The structural identification was carried out on the basis of {sup 1}H and {sup 13}C NMR spectral data and comparison with literature data. The compounds (+)-catechin and epicatechin were submitted to germination inhibition and radicle and hypocotyl growth assays. Results showed some significant activities confirming the initial hypothesis about allelopathic properties of that plant. (author)

  9. Therapeutic Efficacy of Nanocomplex of Poly(Ethylene Glycol) and Catechin for Dry Eye Disease in a Mouse Model.

    Science.gov (United States)

    Lee, Hyesook; Shim, Whuisu; Kim, Chae Eun; Choi, So Yeon; Lee, Haeshin; Yang, Jaewook

    2017-03-01

    We investigated the possibility of the nanocomplex of poly(ethylene glycol) (PEG) and catechin as a new biomedical material to treat dry eye disease. NOD.B10.H2b mice were exposed to an air draft and injected with scopolamine for 10 days. Ten days later, the mice were treated with normal saline (n = 11), 1% catechin (n = 11), 1% PEG (n = 11), and 1% catechin/PEG nanocomplex solution mixture containing catechin and PEG at weight ratios of 1:1 (CP1, n = 11), 1:5 (CP5, n = 11), and 1:10 (CP10, n = 11). All treatments were administered five times a day for 10 days. We estimated the effect of PEG/catechin nanocomplexes on inflammation, tear production, epithelium stabilization, and goblet cell density. Desiccation stress significantly decreased tear production and increased the corneal irregularity score. Furthermore, desiccation stress markedly increased the detached epithelium and decreased the numbers of conjunctival goblet cells. In addition, the expression of proinflammatory-related factors was markedly induced by desiccation stress in the lacrimal glands. However, the PEG/catechin nanocomplex effectively induced an increase in tear production, stabilization of the corneal epithelium, and an increase in conjunctival goblet cells and anti-inflammatory improvements in a PEG dose-dependent manner. In this study, we found that PEG may increase bioavailability of catechin. Therefore, the PEG/catechin nanocomplex can be used as a new biomedical material to treat dry eye disease through stabilization of the tear film and inhibition of inflammation.

  10. Ovariectomy lowers urine levels of unconjugated (+)-catechin, (-)-epicatechin, and their methylated metabolites in rats fed grape seed extract.

    Science.gov (United States)

    Cutts, John K; Peavy, Thomas R; Moore, Doyle R; Prasain, Jeevan; Barnes, Stephen; Kim, Helen

    2013-12-01

    Abstract Steroid hormones modulate expression of enzymes that metabolize xenobiotics, including dietary supplements. Half of the human population undergoes menopause, yet the effect of this age-related loss of ovarian steroid hormones on the metabolism of dietary supplements has yet to be determined. Grape seed extract (GSE) is a dietary supplement comprised of monomeric and oligomeric catechins and has health benefits in models of age-related diseases. We hypothesized that surgically-induced loss of ovarian hormones would increase methylation, glucuronidation, and/or sulfation of the grape seed polyphenols (+)-catechin and (-)-epicatechin. Fourteen-week-old spontaneously hypertensive rats (SHRs) were ovariectomized (OVX) or sham-OVX. At 17 weeks of age, SHRs were gavaged with vehicle (water) or GSE (300 mg/kg body weight) once daily for 6 days. Urinary excretion of (+)-catechin, (-)-epicatechin, and their metabolites was analyzed by liquid chromatography-mass spectrometry. Although total urinary output of (+)-catechin, (-)-epicatechin, and their methylated metabolites was unaffected by OVX, the amounts of (+)-catechin, (-)-epicatechin and their methylated metabolites that were not conjugated with glucuronic acid or sulfate were lowered by OVX. Specifically, urine from OVX SHRs administered GSE contained 30% higher proportions (91.8% vs. 62.3%) of glucuronidated (+)-catechin and (-)-epicatechin and glucuronidated methyl (+)-catechin and methyl (-)-epicatechin than urine from sham-OVX SHRs. However, there were no differences in urinary levels of total methylated or sulfated catechins in OVX SHRs. This is the first quantitative characterization of metabolites of grape seed polyphenols in a model of menopause; it indicates that ovariectomy causes either an increase in expression and/or activity of select uridine 5'-diphospho-glucuronosyltransferase(s).

  11. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Erna Susanti

    2015-12-01

    Conclusions: The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG. Four major catechins were separated and identified by LC-MS/MS, such as EGCG, epigallocatechin, ECG and epicatechin. The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.

  12. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

    OpenAIRE

    Erna Susanti; Ciptati; Retty Ratnawati; ., Aulanni'am; Achmad Rudijanto

    2015-01-01

    Objective: To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone. Methods: Green tea GMB-4 clones were extracted with distilled water at 90 °C. Samples were eluted into the column with 10% ethanol. Subsequently, the column was eluted with 95% ethanol and evaporated separately. Green tea extract was identified by thin layer chromatography. Catechins were separated by the stationary phase in column chromatography using polyamide with 10% eth...

  13. Method for determining the composition of the sugar moiety of a sugar containing compound

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention relates to methods of labeling sugar moieties of sugar containing compounds including glycopeptides. The compounds presented in the present invention facilitate reliable detection of sugar moieties of sugar containing compounds by a combination of spectroscopy methods...

  14. Metode Cepat Identifikasi Flavonoid dari Daun Ocimum sanctum L. (Selasih

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    Diah Dhianawaty

    2012-03-01

    Full Text Available A plant’s effectiveness as a herbal drug comes from its chemical content such as flavonoids. Flavonoids are useful for human body health. Therefore flavonoids content can be used as a marker from the usefulness of a plant, and rapid identification method of flavonoid is needed. The objective of the research was to get a rapid method of flavonoid content identification from Ocimum sanctum. The extraction, isolation and identification of flavonoids from Ocimum sanctum leaves has been done at Medical Chemistry laboratory Faculty of Medicine Universitas Padjadjaran in 2005. Flavonoids were extracted continually by 95% ethanol, were isolated with paper chromatography/cellulose TLC and 2% acetic acid, then continued with elucidation reagents: n-butanol–acetic acid–water, chloroform–acetic acid–water, forestall, 5%, 15%, 35% and 50% acetic acids. Flavonoids were identified with diagnostic reagents and ultraviolet light. Isolation with 2% and 35% acetic acids respectively gave two spots of flavonoids as flavon, FOAc-1 had Rf=0.69 and FOAc-2 had Rf=0.57. The other elucidation reagents gave one spot of flavonoid. In conclusion, isolation with 2% and 35% acetic acids respectively and identification with diagnostic reagent and ultraviolet light is a rapid method for identification of flavonoids content in Ocimum sanctum

  15. Metabolism of Flavonoids in Novel Banana Germplasm during Fruit Development

    Science.gov (United States)

    Dong, Chen; Hu, Huigang; Hu, Yulin; Xie, Jianghui

    2016-01-01

    Banana is a commercially important fruit, but its flavonoid composition and characteristics has not been well studied in detail. In the present study, the metabolism of flavonoids was investigated in banana pulp during the entire developmental period of fruit. ‘Xiangfen 1,’ a novel flavonoid-rich banana germplasm, was studied with ‘Brazil’ serving as a control. In both varieties, flavonoids were found to exist mainly in free soluble form and quercetin was the predominant flavonoid. The most abundant free soluble flavonoid was cyanidin-3-O-glucoside chloride, and quercetin was the major conjugated soluble and bound flavonoid. Higher content of soluble flavonoids was associated with stronger antioxidant activity compared with the bound flavonoids. Strong correlation was observed between antioxidant activity and cyanidin-3-O-glucoside chloride content, suggesting that cyanidin-3-O-glucoside chloride is one of the major antioxidants in banana. In addition, compared with ‘Brazil,’ ‘Xiangfen 1’ fruit exhibited higher antioxidant activity and had more total flavonoids. These results indicate that soluble flavonoids play a key role in the antioxidant activity of banana, and ‘Xiangfen 1’ banana can be a rich source of natural antioxidants in human diets. PMID:27625665

  16. Natural Flavonoids as Promising Analgesic Candidates: A Systematic Review.

    Science.gov (United States)

    Xiao, Xiao; Wang, Xiaoyu; Gui, Xuan; Chen, Lu; Huang, Baokang

    2016-11-01

    Due to the chemical structural diversity and various analgesic mechanisms, an increasing number of studies indicated that some flavonoids from medicinal plants could be promising candidates for new natural analgesic drugs, which attract high interests of advanced users and academic researchers. The aim of this systematic review is to report flavonoids and its derivatives as new analgesic candidates based on the pharmacological evidences. Sixty-four papers were found concerning the potential analgesic activity of 46 flavonoids. In this case, the evidence for analgesic activity of flavonoids and total flavonoids was investigated. Meanwhile, the corresponding analgesic mechanism of flavonoids was discussed by generalizing and analyzing the current publications. Based on this review, the conclusion can be drawn that some flavonoids are promising candidates for painful conditions and deserve particular attention in further research and development.

  17. Frequently Asked Questions about Sugar

    Science.gov (United States)

    ... sodas and other products made with non-nutritive (artificial) sweeteners contain zero calories from added sugars, does that ... is “sugar free” or made with non-nutritive (artificial) sweeteners doesn’t necessarily mean that it’s healthy. Last ...

  18. Flavonoids, flavonoid subclasses and breast cancer risk: a meta-analysis of epidemiologic studies.

    Directory of Open Access Journals (Sweden)

    Chang Hui

    Full Text Available BACKGROUND: Studies have suggested the chemopreventive effects of flavonoids on carcinogenesis. Yet numbers of epidemiologic studies assessing dietary flavonoids and breast cancer risk have yielded inconsistent results. The association between flavonoids, flavonoid subclasses (flavonols, flavan-3-ols, etc. and the risk of breast cancer lacks systematic analysis. OBJECTIVE: We aimed to examine the association between flavonoids, each flavonoid subclass (except isoflavones and the risk of breast cancer by conducting a meta-analysis. DESIGN: We searched for all relevant studies with a prospective cohort or case-control study design published before July 1(st, 2012, using Cochrane library, MEDLINE, EMBASE and PUBMED. Summary relative risks (RR were calculated using fixed- or random-effects models. All analyses were performed using STATA version 10.0. RESULTS: Twelve studies were included, involving 9 513 cases and 181 906 controls, six of which were prospective cohort studies, and six were case-control studies. We calculated the summary RRs of breast cancer risk for the highest vs lowest categories of each flavonoid subclass respectively. The risk of breast cancer significantly decreased in women with high intake of flavonols (RR=0.88, 95% CI 0.80-0.98 and flavones (RR=0.83, 95% CI: 0.76-0.91 compared with that in those with low intake of flavonols and flavones. However, no significant association of flavan-3-ols (RR=0.93, 95% CI: 0.84-1.02, flavanones (summary RR=0.95, 95% CI: 0.88-1.03, anthocyanins (summary RR=0.97, 95% CI: 0.87-1.08 or total flavonoids (summary RR=0.98, 95% CI: 0.86-1.12 intake with breast cancer risk was observed. Furthermore, summary RRs of 3 case-control studies stratified by menopausal status suggested flavonols, flavones or flavan-3-ols intake is associated with a significant reduced risk of breast cancer in post-menopausal while not in pre-menopausal women. CONCLUSIONS: The present study suggests the intake of flavonols

  19. Genetic diversity of UPASI tea clones (Camellia sinensis (L.) O. Kuntze) on the basis of total catechins and their fractions.

    Science.gov (United States)

    Saravanan, M; Maria John, K M; Raj Kumar, R; Pius, P K; Sasikumar, R

    2005-03-01

    Tea leaf catechins and the ratio of dihydroxylated to trihydroxylated catechin fractions were analysed to identify the genetic diversity of 26 UPASI released tea clones. Principal component analysis (PCA) based on regression factor separated tea clones into five groups according to their jats (Jats are region based rays for e.g., Assam, China and Cambod origin) as well as their quality constituents (such as total polyphenols, total catechins, amino acids in the green leaves and liquor characteristics of black tea), particularly the catechins. Group 1 represented medium quality (quality of the final produce) clones, such as UPASI-10, UPASI-12 and UPASI-15 and drought tolerant clones like UPASI-1, UPASI-2, UPASI-9 and UPASI-10. Group 2 contained purely "China" cultivars while group 3 possessed high quality tea cultivars. "Assam" (group 5) teas had the lowest ratio of dihydroxylated to trihydroxylated catechin fractions (1:4) than the "Chinery" (group 2) teas (1:5). This biochemical differentiation indicated that there is a vast genetic diversity in UPASI released tea clones in terms of catechin fractions, even though the majority of them were selected from one tea estate located in the Nilgiris.

  20. Development of rapid and simultaneous quantitative method for green tea catechins on the bioanalytical study using UPLC/ESI-MS.

    Science.gov (United States)

    Misaka, Shingen; Kawabe, Keisuke; Onoue, Satomi; Werba, José Pablo; Giroli, Monica; Kimura, Junko; Watanabe, Hiroshi; Yamada, Shizuo

    2013-01-01

    A rapid and quantitative analytical method for the simultaneous determination of green tea catechins using ultra-performance liquid chromatography/electrospray ionization-mass spectrometry was developed. Total analytical run time was 3.5 min for the detection of (-)-epicatechin (EC), (-)-epicatechin-3-O-gallate (ECG), (-)-epigallocatechin (EGC), (-)-epigallocatechin-3-O-gallate (EGCG) and myricetin as the internal standard (IS) in rat plasma. The calibration curves were linear over the range of 10-5000 ng/mL for all the catechins. The inter- and intra-day precision (relative standard deviation) and accuracy (percentage deviation) of the method were both lower than 10%. The average extraction recoveries in plasma ranged from 68.5 to 86.5%, and the lower limits of quantification of EC, EGC, ECG and EGCG were 10 ng/mL with a signal-to-noise ratio of >10. The assay developed was successfully applied to a pharmacokinetic study of catechins following intravenous and intragastric administrations of green tea extract in rats. Plasma concentrations of four catechins were detected up to 5-24 h after administration, and the pharmacokinetic parameters of catechins were in agreement with previous studies. From these findings, taken together with the high productivity and precision, the developed method could be a reliable and reproducible tool for the evaluation of pharmacokinetic properties of catechins.

  1. Sugar beet (Beta vulgaris L.).

    Science.gov (United States)

    Kagami, Hiroyo; Kurata, Masayuki; Matsuhira, Hiroaki; Taguchi, Kazunori; Mikami, Tetsuo; Tamagake, Hideto; Kubo, Tomohiko

    2015-01-01

    Creating transgenic plants is invaluable for the genetic analysis of sugar beet and will be increasingly important as sugar beet genomic technologies progress. A protocol for Agrobacterium-mediated transformation of sugar beet is described in this chapter. Our protocol is optimized for a sugar beet genotype that performs exceptionally well in tissue culture, including the steps of dedifferentiation, callus proliferation, and regeneration. Because of the infrequent occurrence of such a genotype in sugar beet populations, our protocol includes an in vitro propagation method for germplasm preservation. The starting materials for transgenic experiments are aseptic shoots grown from surface-sterilized seed balls. Callus is induced from leaf explants and subsequently infected with Agrobacterium. Plantlets are regenerated from transgenic callus and vernalized for flowering, if necessary. The efficiency of transformation was quite high; in our laboratory, the culture of only ten leaf explants, on average, generated one transgenic plant.

  2. Use of cyclodextrins to recover catechin and epicatechin from red grape pomace.

    Science.gov (United States)

    López-Miranda, Santiago; Serrano-Martínez, Ana; Hernández-Sánchez, Pilar; Guardiola, Lucía; Pérez-Sánchez, Horacio; Fortea, Isabel; Gabaldón, José Antonio; Núñez-Delicado, Estrella

    2016-07-15

    The capacity of cyclodextrins (CDs) to extract phenolic compounds from grape pomace was evaluated and compared with that of ethanol/water or aqueous extraction. The extraction method (stirring and ultrasound), temperature and time were also studied. Total phenolic compounds (TPC) and antioxidant activity were measured, and HPLC analysis was used to identify the phenolic compounds. The extracts obtained using the ethanol/water mixture presented the highest TPC content and antioxidant activity, followed by those obtained using CD solutions. The addition of CDs to the extractant agent had a selective effect on the extraction of catechin and epicatechin. The yield of catechin and epicatechin by using aqueous solutions of CDs was similar to that obtained using organic solvents as ethanol.

  3. Urinary Sugars--A Biomarker of Total Sugars Intake.

    Science.gov (United States)

    Tasevska, Natasha

    2015-07-01

    Measurement error in self-reported sugars intake may explain the lack of consistency in the epidemiologic evidence on the association between sugars and disease risk. This review describes the development and applications of a biomarker of sugars intake, informs its future use and recommends directions for future research. Recently, 24 h urinary sucrose and fructose were suggested as a predictive biomarker for total sugars intake, based on findings from three highly controlled feeding studies conducted in the United Kingdom. From this work, a calibration equation for the biomarker that provides an unbiased measure of sugars intake was generated that has since been used in two US-based studies with free-living individuals to assess measurement error in dietary self-reports and to develop regression calibration equations that could be used in future diet-disease analyses. Further applications of the biomarker include its use as a surrogate measure of intake in diet-disease association studies. Although this biomarker has great potential and exhibits favorable characteristics, available data come from a few controlled studies with limited sample sizes conducted in the UK. Larger feeding studies conducted in different populations are needed to further explore biomarker characteristics and stability of its biases, compare its performance, and generate a unique, or population-specific biomarker calibration equations to be applied in future studies. A validated sugars biomarker is critical for informed interpretation of sugars-disease association studies.

  4. Preventive role of green tea catechins from obesity and related disorders especially hypercholesterolemia and hyperglycemia

    OpenAIRE

    Ahmad, Rabia Shabir; Butt, Masood Sadiq; Sultan, M Tauseef; Mushtaq, Zarina; Ahmad, Shakeel; Dewanjee, Saikat; De Feo, Vincenzo; Zia-Ul-Haq, Muhammad

    2015-01-01

    Background During the last few years, scientific investigations have proposed diet based regimens to prevent several health ailments including obesity, hypercholesterolemia and diabetes. In this regard, a promising tool is the use of functional foods/nutraceuticals. Present research project was an attempt to explore nutraceutical worth of locally grown green tea variety (Qi-Men) against lifestyle related disorders. Methods Functional drinks (T2 and T3) were prepared by adding catechins and ep...

  5. Phenolation of ±catechin with mineral acids. II. Identification of new reaction products

    Science.gov (United States)

    Weiling Peng; Anthony H. Conner; Richard W. Hemingway

    1997-01-01

    To investigate the reactions that occur in the flavanoid unit during the liquefaction of tannin in phenol, the phenolysis of ±catechin was studied using either H2SO4, HCl, or BF3 2H2O as acid catalyst. In addition to 2-[3-(3,4-dihydroxyphenyl)-2-hydroxy-3-(4-hydroxyphenyl)propyl]-1,3,5-benzenetriol (1) and 2-[(3,4-dihydroxyphenyl)(4-hydroxyphenyl)methyl]-2,3-dihydro-4,...

  6. PHYTOCHEMICAL EVALUATION OF HYDROXY CITRIC ACID, CATECHINS AND CALCIUM PANTOTHENATE PRESENT IN HERBAL FORMULATION

    Directory of Open Access Journals (Sweden)

    S. P. Karuppiah

    2012-01-01

    Full Text Available The analytical method for the estimation of phytochemical active ingredients present in Garginia combogia extract, Green tea extract with calcium pantothenate for herbal formulations are evaluated for it’s Assay content and dissolution release. This herbal formulation with slim formula consists of several active ingredients such as Hydroxy Citric acid, catechins and calcium pantothenate. The HPLC method for the estimation of active content and the in-vitro dissolution release is developed for the study.

  7. Quantitative analysis of catechins in Saraca asoca and correlation with antimicrobial activity

    Institute of Scientific and Technical Information of China (English)

    Amey Shirolkar; Anjum Gahlaut; Anil K. Chhillar; Rajesh Dabur

    2013-01-01

    Herbal medicines are highly complex and have unknown mechanisms in diseases treatment. Saraca asoca (Roxb.), De. Wild has been recommended to treat gynecological disorders and used in several commercial polyherbal formulations. In present study, efforts have been made to explore antimicrobial activity and its co-relation with the distributions of catechins in the organs of S. asoca using targeted MS/MS. Eight extracts (cold and hot water) from four different organs of S. asoca and two drugs were prepared and antimicrobial activity was assessed by microbroth dilution assay. Quantitative and qualitative analysis of catechins in crude extracts was done by using targeted and auto-MS/MS and correlated with antimicrobial activity. (þ)-Catechin and (þ)-epicatechin and their biosynthesis related compound were found to be up-regulated in regenerated bark and leaves extracts. (?)-Epigallocatechin was found to be significantly higher in bark water extract as compared to others but showed low antimicrobial activity. Result showed down-regulation of (?)-epigallocatechin and up-regulation of (þ)-catechin and (þ)-epicatechin in the regenerated bark and leaves of S. asoca. It might be the contributing factor in the antimicrobial activity of regenerated bark and leaves of the plant. The concentration of (þ)-epicatechin in processed drugs (Ashokarishta) from Baidyanath was found to be seven times higher than that of Dabur Pvt. Ltd., but no antimicrobial activity was observed, indicating the variations among the plant based drugs. This will be helpful in rational use of S. asoca parts. Furthermore, the analytical method developed is sensitive, repeatable and reliable; therefore, it is suitable for quality control of herbal drugs.

  8. Life Cycle Assessment of Sugar Production (VB)

    DEFF Research Database (Denmark)

    Teljigovic, Mehmed; Mengiardi, Jon; Factor, Gabriela

    1999-01-01

    The environmental organisation NOAH has proposed carrying out an environmental assessment of two different sugar productions (using sugar beet or sugar cane) in order to illustrate which of the systems has a higher environmental impact for sugar consumption in Denmark. Therefore a comparison...... will be made between sugar from sugar beet produced in Denmark versus sugar produces from sugar cane in a tropical country, Brazil, and transported afterwards to Denmark. To evaluate the environmental aspects of these two product systems a Life Cycle Assessement (LCA) will be carried out.From the results...... obtained in the present LCA of sugar produces from sugar canes or sugar beet it is difficult to make an immediate choice between the two possibilities. Indeed, Quantitative results from the EDIP (Environmental Design of Industrial Products) software are globally similar for both ways of producing sugar...

  9. Eliminate Sweetened Drinks, Cut Kids' Sugar Intake

    Science.gov (United States)

    ... fullstory_161163.html Eliminate Sweetened Drinks, Cut Kids' Sugar Intake Average U.S. child consumes about 80 grams ... Looking for the quickest way to cut added sugar from your kid's diet? Eliminate sugar-sweetened drinks, ...

  10. Human Serum Albumin Increases the Stability of Green Tea Catechins in Aqueous Physiological Conditions.

    Directory of Open Access Journals (Sweden)

    Angelo Zinellu

    Full Text Available Epicatechin (EC, epigallocatechin (EGC, epicatechingallate (ECG and epigallocatechingallate (EGCG are antioxidants present in the green tea, a widely used beverage whose health benefits are largely recognized. Nevertheless, major physicochemical limitations, such as the high instability of catechins, pose important questions concerning their potential pharmacological use. Recent studies indicate that binding of catechins with plasmatic proteins may modulate their plasma concentration, tissue delivery and biological activity. After 5 minutes of incubation with HSA both ECG and EGCG were fully bound to HSA, while after 48h incubation only 41% of EC and 70% of EGC resulted linked. HSA had a strong stabilizing effect on all catechins, which could be found in solution between 29 and 85% even after 48h of incubation. In the absence of HSA, EGC and EGCG disappeared in less than 24h, while ECG and EC were found after 48h at 5 and 50%, respectively. The stabilizing effect of HSA toward EGCG, obtained in aqueous physiological conditions, resulted stronger in comparison to cysteine and HCl, previously reported to stabilize this polyphenol. Because of the multitude of contradictory data concerning in vivo and in vitro antioxidant-based experimentations, we believe our work may shed some light on this debated field of research.

  11. Determination and pharmacokinetic study of catechin in rat plasma by HPLC

    Institute of Scientific and Technical Information of China (English)

    Li Xie; Xin-Nan Li; De-Xi Jiang; Dan Zhang

    2011-01-01

    A high performance liquid chromatographic method was developed and validated for the quantitative determination of catechin in rat plasma and its pharmacokinetic study after intragastric administration of Catechu and Xiongdanjiangre Wan into SD rats. Plasma samples were prepared by protein precipitation using methanol-5% aqueous zinc sulfate (70:30, v/v) as precipitant. Chromatographic separation was achieved on Hypersil Cl8 column (250 mm~ 4.6 mm, 10 pm) with acetonitrile-water-triethylamine (6:94:0.3, v/v/v, pH 4.0+0.1, adjusted with phos- phoric acid) as mobile phase, followed by a UV detection at 207 nm. Good linearity was obtained over the range of 0.143-7.15 mg/L of catechin, with correlation coefficient of 0.9992. The method was simple, sensitive, accurate and reproducible and' has been successfully applied to the pharmacokinetic study of catechin in rat plasma.

  12. Protective action of green tea catechins in neuronal mitochondria during aging.

    Science.gov (United States)

    Assuncao, Marco; Andrade, Jose Paulo

    2015-01-01

    Mitochondria are central players in the regulation of cell homeostasis. They are essential for energy production but at the same time, reactive oxygen species accumulate as byproducts of the electron transport chain causing mitochondrial damage. In the central nervous system, senescence and neurodegeneration occur as a consequence of mitochondrial oxidative insults and impaired electron transfer. The accumulation of several oxidation products in neurons during aging prompts the idea that consumption of antioxidant compounds may delay neurodegenerative processes. Tea, one of the most consumed beverages in the world, presents benefits to human health that have been associated to its abundance in polyphenols, mainly catechins, that possess powerful antioxidant properties in vivo and in vitro. In this review, the focus will be placed on the effects of green tea catechins in neuronal mitochondria. Although these compounds reach the brain in small quantities, there are several possible targets, signaling pathways and molecular machinery impinging in the mitochondria that will be highlighted. Accumulated evidence thus far seems to indicate that catechins help prevent neurodegeneration and delay brain function decline.

  13. Human Serum Albumin Increases the Stability of Green Tea Catechins in Aqueous Physiological Conditions.

    Science.gov (United States)

    Zinellu, Angelo; Sotgia, Salvatore; Scanu, Bastianina; Forteschi, Mauro; Giordo, Roberta; Cossu, Annalisa; Posadino, Anna Maria; Carru, Ciriaco; Pintus, Gianfranco

    2015-01-01

    Epicatechin (EC), epigallocatechin (EGC), epicatechingallate (ECG) and epigallocatechingallate (EGCG) are antioxidants present in the green tea, a widely used beverage whose health benefits are largely recognized. Nevertheless, major physicochemical limitations, such as the high instability of catechins, pose important questions concerning their potential pharmacological use. Recent studies indicate that binding of catechins with plasmatic proteins may modulate their plasma concentration, tissue delivery and biological activity. After 5 minutes of incubation with HSA both ECG and EGCG were fully bound to HSA, while after 48h incubation only 41% of EC and 70% of EGC resulted linked. HSA had a strong stabilizing effect on all catechins, which could be found in solution between 29 and 85% even after 48h of incubation. In the absence of HSA, EGC and EGCG disappeared in less than 24h, while ECG and EC were found after 48h at 5 and 50%, respectively. The stabilizing effect of HSA toward EGCG, obtained in aqueous physiological conditions, resulted stronger in comparison to cysteine and HCl, previously reported to stabilize this polyphenol. Because of the multitude of contradictory data concerning in vivo and in vitro antioxidant-based experimentations, we believe our work may shed some light on this debated field of research.

  14. Calcium desensitizer catechin reverses diastolic dysfunction in mice with restrictive cardiomyopathy.

    Science.gov (United States)

    Zhang, Lei; Nan, Changlong; Chen, Yuan; Tian, Jie; Jean-Charles, Pierre-Yves; Getfield, Cecile; Wang, Xiaoqing; Huang, Xupei

    2015-05-01

    Diastolic dysfunction refers to an impaired relaxation and an abnormality in ventricular blood filling during diastole while systolic function is preserved. Cardiac myofibril hypersensitivity to Ca(2+) is a major factor that causes impaired relaxation of myocardial cells. The present study investigates the effect of the green tea extract catechins on myofibril calcium desensitization and restoration of diastolic function in a restrictive cardiomyopathy (RCM) mouse model with cardiac troponin mutations. Wild type (WT) and RCM mice were treated daily with catechin (epigallocatechin-3-gallate, EGCg, 50 mg/kg body weight) for 3 months. Echocardiography and cell based assays were performed to measure cardiac structure and flow-related variables including chamber dimensions, fraction shortening, trans-mitral flow patterns in the experimental mice. In addition, myocyte contractility and calcium dynamics were measured in WT and RCM cardiomyocytes treated in vitro with 5 μM EGCg. Our data indicated that RCM mice treated with EGCg showed an improved diastolic function while systolic function remained unchanged. At the cellular level, sarcomere relaxation and calcium decay were accelerated in RCM myocardial cells treated with EGCg. These results suggest that catechin is effective in reversing the impaired relaxation in RCM myocardial cells and rescuing the RCM mice with diastolic dysfunction.

  15. Transcripts of Anthocyanidin Reductase and Leucoanthocyanidin Reductase and Measurement of Catechin and Epicatechin in Tartary Buckwheat

    Directory of Open Access Journals (Sweden)

    Yeon Bok Kim

    2014-01-01

    Full Text Available Anthocyanidin reductase (ANR and leucoanthocyanidin reductase (LAR play an important role in the monomeric units biosynthesis of proanthocyanidins (PAs such as catechin and epicatechin in several plants. The aim of this study was to clone ANR and LAR genes involved in PAs biosynthesis and examine the expression of these two genes in different organs under different growth conditions in two tartary buckwheat cultivars, Hokkai T8 and T10. Gene expression was carried out by quantitative real-time RT-PCR, and catechin and epicatechin content was analyzed by high performance liquid chromatography. The expression pattern of ANR and LAR did not match the accumulation pattern of PAs in different organs of two cultivars. Epicatechin content was the highest in the flowers of both cultivars and it was affected by light in only Hokkai T8 sprouts. ANR and LAR levels in tartary buckwheat might be regulated by different mechanisms for catechin and epicatechin biosynthesis under light and dark conditions.

  16. The case against (-)-catechin involvement in allelopathy of Centaurea stoebe (spotted knapweed)

    Science.gov (United States)

    Dayan, Franck E; Bajsa, Joanna; Meepagala, Kumudini M; Hufbauer, Ruth A; Blair, Amy C

    2009-01-01

    Proving allelopathic chemical interference is a daunting endeavor, in that production and movement of a phytotoxin from a donor plant to a receiving plant must be demonstrated in the substrate in which the plants grow, which is usually a complex soil matrix. The soil levels or soil flux levels of the compound generated by the donor must be proven to be sufficient to adversely affect the receiving plant. Reports of (-)-catechin to be the novel weapon used by Centaurea stoebe (spotted knapweed) to invade new territories are not supported by the paper featured in this Addendum, nor by papers produced by two other laboratories. These papers find that (-)-catechin levels in soil in which C. stoebe grows are orders of magnitude below levels that cause only minor growth effects on reported sensitive species. Furthermore, the claim that (-)-catechin acts as a phytotoxin through causing oxidative damage is refuted by the fact that the molecule is a strong antioxidant and is quickly degraded by extracellular root enzymes. PMID:19816095

  17. Industrial wastewater treatment plant of sugar production

    OpenAIRE

    Čad, Luka

    2016-01-01

    Sugar as product in our every day’s life’s been consumed in enormous quantities as one of main resources in food and drink industry. Production processes of sugar from sugar beet bring significant environmental impacts with it’s waste waters as the biggest pollutant. The thesis deals with sugar production waste water’s treatment process by presenting an example of waste water treatment plant of sugar factory, therefor presenting the production processes in sugar factories and their environmen...

  18. In vitro antioxidant profiles of some flavonoids

    Science.gov (United States)

    Aksoy, Mine; Gülçin, Ilhami; Küfrevioǧlu, Ö. Irfan

    2016-04-01

    Baicalin ((2S,3S,4S,5R,6S)-6-(5,6-dihydroxy-4-oxo-2-phenyl-chromen-7-yl)oxy-3,4,5-trihydroxy-tetrahydropyran-2-carboxylic acid) and baicalein (5,6,7-trihydroxyflavone) are a flavone, a type of flavonoid. Baicalin is the glucuronide of baicalein. Phlorizin, or phloridzin is a naturally occurring flavonoid produced in some plants. It belongs to the group of dihydrochalcones. In this study, we investigated the in vitro antioxidant properties of baicalin, baicalein and phloridzin using different methods including ferric ion (Fe3+) reducing power, cupric ion (Cu2+) reducing power (CUPRAC method), reduction of Fe3+-TPTZ complex, 1,1-diphenyl-2-picrylhydrazyl free radicals (DPPH.) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid radicals (ABTS.+) scavenging activities. Also, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and α-Tocopherol were used as standard antioxidants.

  19. Chemistry and Biological Activities of Flavonoids: An Overview

    Directory of Open Access Journals (Sweden)

    Shashank Kumar

    2013-01-01

    Full Text Available There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about their nuclear structure. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. Most recent researches have focused on the health aspects of flavonoids for humans. Many flavonoids are shown to have antioxidative activity, free radical scavenging capacity, coronary heart disease prevention, hepatoprotective, anti-inflammatory, and anticancer activities, while some flavonoids exhibit potential antiviral activities. In plant systems, flavonoids help in combating oxidative stress and act as growth regulators. For pharmaceutical purposes cost-effective bulk production of different types of flavonoids has been made possible with the help of microbial biotechnology. This review highlights the structural features of flavonoids, their beneficial roles in human health, and significance in plants as well as their microbial production.

  20. Which sources of flavonoids: complex diets or dietary supplements?

    Science.gov (United States)

    Egert, Sarah; Rimbach, Gerald

    2011-01-01

    There is increasing interest in the potential health benefits of dietary flavonoids. Fruits and vegetables, tea, and cocoa are rich natural sources of flavonoids. Epidemiological studies have indicated that consumption of these foods is likely to be associated with a reduced risk of cardiovascular disease, but the etiology of this benefit is not yet clearly defined. Furthermore, in some acute interventions, a positive effect of tea and cocoa on vascular function has been reported. An alternative source of flavonoids is dietary supplements, which have become increasingly popular in the recent past. In this context, it needs to be critically evaluated whether vascular health-promoting and other positive properties of flavonoid-rich diets can be replaced by purified flavonoids as dietary supplements. Plant sources of flavonoids contain a complex mixture of secondary plant metabolites and not only flavonoids per se. This complex mixture of secondary plant metabolites cannot be simply exchanged by single purified compounds as dietary supplements. If flavonoids are given as dietary supplements, toxicity issues as well as nutrient drug interactions need to be taken into account. Purified flavonoids given in high doses as dietary supplements may affect trace element, folate, and vitamin C status. Furthermore, they may exhibit antithyroid and goitrogenic activities. In this review article, the available literature on the safety issues surrounding high dose supplemental flavonoid consumption has been summarized.

  1. Advance on the Flavonoid C-glycosides and Health Benefits.

    Science.gov (United States)

    Xiao, Jianbo; Capanoglu, Esra; Jassbi, Amir Reza; Miron, Anca

    2016-07-29

    The dietary flavonoids, especially their glycosides, are the most vital phytochemicals in diets and are of great general interest due to their diverse bioactivity. Almost all natural flavonoids exist as their O-glycoside or C-glycoside forms in plants. The dietary flavonoid C-glycosides have received less attention than their corresponding O-glycosides. This review summarizes current knowledge regarding flavonoid C-glycosides and their influence on human health. Among the flavonoid C-glycosides, flavone C-glycosides, especially vitexin, isoorientin, orientin, isovitexin and their multiglycosides are more frequently mentioned than others. Flavonoid C-monoglycosides are poorly absorbed in human beings with very few metabolites in urine and blood and are deglycosylated and degraded by human intestinal bacteria in colon. However, flavonoid C-multiglycosides are absorbed unchanged in the intestine and distributed to other tissues. Flavonoid C-glycosides showed significant antioxidant activity, anticancer and antitumor activity, hepatoprotective activity, anti-inflammatory activity, anti-diabetes activity, antiviral activity, antibacterial and antifungal activity, and other biological effects. It looks like that the C-glycosylflavonoids in most cases showed higher antioxidant and anti-diabetes potential than their corresponding O-glycosylflavonoids and aglycones. However, there is a lack of in vivo data on the biological benefits of flavonoid C-glycosides. It is necessary to investigate more on how flavonoid C-glycosides prevent and handle the diseases.

  2. Chemistry and biological activities of flavonoids: an overview.

    Science.gov (United States)

    Kumar, Shashank; Pandey, Abhay K

    2013-01-01

    There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about their nuclear structure. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. Most recent researches have focused on the health aspects of flavonoids for humans. Many flavonoids are shown to have antioxidative activity, free radical scavenging capacity, coronary heart disease prevention, hepatoprotective, anti-inflammatory, and anticancer activities, while some flavonoids exhibit potential antiviral activities. In plant systems, flavonoids help in combating oxidative stress and act as growth regulators. For pharmaceutical purposes cost-effective bulk production of different types of flavonoids has been made possible with the help of microbial biotechnology. This review highlights the structural features of flavonoids, their beneficial roles in human health, and significance in plants as well as their microbial production.

  3. A new flavonoid glucoside from Cassia angustifolia

    Institute of Scientific and Technical Information of China (English)

    Qiu Ping Wu; Zhu Ju Wang; Li Ying Tang; Mei Hong Fu; Yan He

    2009-01-01

    A new flavonoid glucoside with a known one was isolated from the leaves of Cassia angustifolia. Based on the spectral analysis,including MS, 1H NMR, 13C NMR, DEPT, 1H-1HCOSY, HMQC, HMBC and NOSEY, their chemical structures were determined as kaempferol-3-O-[(6"-O-trans-sinnapoyl)-B-D-glucopyranosyl (1 -6)]-B-D-glucopyranoside 1 and apigenin-6,8-di-C-glycoside 2.

  4. Litchi Flavonoids: Isolation, Identification and Biological Activity

    Directory of Open Access Journals (Sweden)

    Yueming Jiang

    2007-04-01

    Full Text Available The current status of the isolation, identification, biological activity, utilization and development prospects of flavonoids found in litchi fruit pericarp (LFP tissues is reviewed. LFP tissues account for approximately 15% by weight of the whole fresh fruit and are comprised of significant amount of flavonoids. The major flavonoids in ripe LFP include flavonols and anthocyanins. The major flavanols in the LFP are reported to be procyanidin B4, procyanidin B2 and epicatechin, while cyanindin-3-rutinside, cyanidin-3-glucoside, quercetin-3-rutinosde and quercetin-3-glucoside are identified as the important anthocyanins. Litchi flavanols and anthocyanins exhibit good potential antioxidant activity. The hydroxyl radical and superoxide anion scavenging activities of procyanidin B2 are greater than those of procyanidin B4 and epicatechin, while epicatechin has the highest α,α-diphenyl-β-picrylhydrazyl radical (DPPH· scavenging activity. In addition to the antioxidant activity, LFP extract displays a dose- and time-dependent inhibitory effect on human breast cancer, which could be attributed, in part, to its inhibition of proliferation and induction of apoptosis in cancer cells through upregulation and down-regulation of multiple genes. Furthermore, various anticancer activities are observed for epicatechin, procyanidin B2, procyanidin B4 and the ethyl acetate fraction of LFP tissue extracts. Procyanidin B4 and the ethyl acetate fraction show a stronger inhibitory effect on HELF than MCF-7 proliferation, while epicatechin and procyanidin B2 have lower cytotoxicities towards MCF-7 and HELF than paclitaxel. It is therefore suggested that flavonoids from LFP might be potentially useful components for functional foods and/or anti-breast cancer drugs.

  5. Flavonoids from Lactuca quercina and L. tatarica

    Directory of Open Access Journals (Sweden)

    Wanda Kisiel

    2014-01-01

    Full Text Available From aerial parts of Lactuca quercina L. and Lactuca tatarica C. A. Meyer six flavonoids were isolated using different chromatographic techniques. Of these, three compounds, apigenin, luteolin and quercetin-3-O-β-glucopyranoside, were found in both species, two compounds, apigenin-7-O-β-glucopyranoside and kaempferol-3-O-β-glucopyranoside, originated from the latter, and one compound, luteolin-7-O-β-glucopyranoside, from the former.

  6. A New Flavonoid Glycoside from Lysionotus pauciflorus.

    Science.gov (United States)

    Luo, Wei; Wen, Yaya; Tu, Yanbei; Du, Hongjian; Li, Qin; Zhu, Chao; Li, Yanfang

    2016-05-01

    Ten flavonoids (1-10), including a new glycoside (nevadensin-7-sambubioside, 7), together with a phenylpropanoid glycoside (11) were isolated from Lysionotus pauciflorus. Their structures were elucidated by a combination of spectroscopic methods and comparing with literature data. Five compounds (1, 3, 4, 8, and 9) were obtained from the family Gesneriaceae for the first time. The new compound was evaluated in vitro for anticholinesterase activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), but was found to be inactive.

  7. Tocopherols and flavonoids of SOS-7 halophyte

    Directory of Open Access Journals (Sweden)

    El-Shami, S. M.

    1993-10-01

    Full Text Available Halophyte is an oil seed coded as SOS-7 (Salicomia Oil Seed, 7th year of selection. Tocopherol constituents of SOS-7 halophyte oil were determined directly in the oil by using high pressure liquid chromatography coupled to fluorescence detector. It was found that the oil contains 710 ppm total tocopherols. The tocopherol constituents, alpha, beta, gamma and delta, were found at the level of 38.2,1.0, 58.7 and 2.1% respectively. Nine flavonoid glycosides were isolated and identified from the seeds and it was found that they belong to the flavonol class of flavonoids. These flavonol compounds were identified as: quercetin-3, 7-diglucoside, quercetin-3-glucoside-7-galactoside, quercetin-3-sophoroside, quercetin-3-glucoside, quercetin-3-galactoside, isorhamnetin-3, 7-di-glucoside, isorhamnetin-3-glucoside, kaempferol-3, 7-diglucoside and kaempferol-3-glucoside.

    Halofito es una semilla oleaginosa codificada como SOS-7 (semilla oleaginosa Salicomia, séptimo año de selección. Los tocoferoles del aceite de halofito SOS-7 fueron determinados directamente en el aceite usando cromatografía líquida de alta presión acoplada a detector fluorescente. Se encontró que el aceite contenía 710 ppm de tocoferoles totales. Los tocoferoles alfa, beta, gamma y delta, se encontraron a niveles de 38.2,1.0, 58.7 y 2.1%, respectivamente. Nueve glicósidos flavonoides fueron aislados e identificados de las semillas y se encontró que pertenecen a la clase flavonol dentro de los flavonoides. Estos flavonoles fueron identificados como: quercetina-3,7-diglucosido, quercetina-3-glucosido-7-galactosido, quercetina-3-soforosido, quercetina- 3-glucosido, quercetina-3-galactosido, isorannetina-3, 7-di-glucosido, isorannetina-3-glucosido, kampferol-3, 7-diglucosido y kampferol-3-glucosido.

  8. Flavonoid profile of green asparagus genotypes.

    Science.gov (United States)

    Fuentes-Alventosa, J M; Jaramillo, S; Rodríguez-Gutiérrez, G; Cermeño, P; Espejo, J A; Jiménez-Araujo, A; Guillén-Bejarano, R; Fernández-Bolaños, J; Rodríguez-Arcos, R

    2008-08-27

    The determination of flavonoid profiles from different genotypes of triguero asparagus and their comparison to those from green asparagus commercial hybrids was the main goal of this study. The samples consisted of 32 commercial hybrids and 65 genotypes from the Huetor-Tajar population variety (triguero). The analysis of individual flavonoids by HPLC-DAD-MS has allowed the determination of eight naturally occurring flavonol derivatives in several genotypes of triguero asparagus. Those compounds included mono-, di-, and triglycosides of three flavonols, that is, quercetin, isorhamnetin, and kaempferol. The detailed analysis of the flavonoid profiles revealed significant differences among the distinct genotypes. These have been classified in three distinct groups as the result of a k-means clustering analysis, two of them containing both commercial hybrids and triguero asparagus and another cluster constituted by 21 genotypes of triguero asparagus, which contain several key flavonol derivatives able to differentiate them. Hence, the triglycosides tentatively identified as quercetin-3-rhamnosyl-rutinoside, isorhamnetin-3-rhamnosyl-rutinoside, and isorhamnetin-3-O-glucoside have been detected only in the genotypes grouped in the above-mentioned cluster. On the other hand, the compound tentatively identified as isorhamnetin-3-glucosyl-rutinoside was present in most genotypes of triguero asparagus, whereas it has not been detected in any of the commercial hybrids.

  9. The effects of co-administration of butter on the absorption, metabolism and excretion of catechins in rats after oral administration of tea polyphenols.

    Science.gov (United States)

    Zhang, Liang; Han, Yuhui; Xu, Liwei; Liang, Yuhong; Chen, Xin; Li, Junsong; Wan, Xiaochun

    2015-07-01

    In Southwest China, tea polyphenols are usually utilized by way of butter tea. Tea polyphenols inhibit the absorption and biosynthesis of fatty acids in vivo, but the effects of butter on the pharmacokinetics of tea polyphenols have drawn less concern. A rapid UHPLC-MS/MS method was used to quantitatively determine the catechins in the plasma, feces and bile of rats after the oral administration of tea polyphenol or its combination with butter. In comparison with the single tea polyphenol treatment, the maximum plasma concentrations (Cmax) of the free EGCG, EGC, EC, GCG, GC and ECG significantly decreased after the co-administration of butter. The mean residence times (MRT) of the free EGCG, EGC, EC, GC and ECG were also significantly prolonged. When the plasma samples were treated with β-glucuronidase and arylsulfatase, the pharmacokinetic parameters of the total catechins (free and conjugated forms) were not affected by the co-administration of butter. These results indicated that the total absorption of catechins was not affected by butter, but the metabolism of catechins had been changed. Furthermore, the fecal catechins were significantly increased by butter. The total fecal amount and excretion ratio of all catechins were increased highly. The biliary excretion of EGCG, EGC, EC, GCG and GC was significantly increased by the co-administration of butter. To sum up, the butter changed the metabolism of catechins in vivo by decreasing the plasma concentration of the free catechins but increasing the conjugated catechins.

  10. Direct interaction of natural and synthetic catechins with signal transducer activator of transcription 1 affects both its phosphorylation and activity

    KAUST Repository

    Menegazzi, Marta

    2013-12-10

    Our previous studies showed that (-)-epigallocatechin-3-gallate (EGCG) inhibits signal transducer activator of transcription 1 (STAT1) activation. Since EGCG may be a promising lead compound for new anti-STAT1 drug design, 15 synthetic catechins, characterized by the (-)-gallocatechin-3-gallate stereochemistry, were studied in the human mammary MDA-MB-231 cell line to identify the minimal structural features that preserve the anti-STAT1 activity. We demonstrate that the presence of three hydroxyl groups of B ring and one hydroxyl group in D ring is essential to preserve their inhibitory action. Moreover, a possible molecular target of these compounds in the STAT1 pathway was investigated. Our results demonstrate a direct interaction between STAT1 protein and catechins displaying anti-STAT1 activity. In particular, surface plasmon resonance (SPR) analysis and molecular modeling indicate the presence of two putative binding sites (a and b) with different affinity. Based on docking data, site-directed mutagenesis was performed, and interaction of the most active catechins with STAT1 was studied with SPR to test whether Gln518 on site a and His568 on site b could be important for the catechin-STAT1 interaction. Data indicate that site b has higher affinity for catechins than site a as the highest affinity constant disappears in the H568ASTAT1 mutant. Furthermore, Janus kinase 2 (JAK2) kinase assay data suggest that the contemporary presence in vitro of STAT1 and catechins inhibits JAK2-elicited STAT1 phosphorylation. The very tight catechin-STAT1 interaction prevents STAT1 phosphorylation and represents a novel, specific and efficient molecular mechanism for the inhibition of STAT1 activation. © Copyright 2014 Federation of European Biochemical Societies. All rights reserved.

  11. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    Erna Susanti; Ciptati; Retty Ratnawati; Aulanniam; Achmad Rudijanto

    2015-01-01

    Objective: To identify the bioactive compounds in catechins isolation and its compo-nents from green tea GMB-4 clone. Methods: Green tea GMB-4 clones were extracted with distilled water at 90 ? C. Samples were eluted into the column with 10%ethanol. Subsequently, the column was eluted with 95% ethanol and evaporated separately. Green tea extract was identified by thin layer chromatography. Catechins were separated by the stationary phase in column chroma-tography using polyamide with 10% ethanol eluent and 95% ethanol. The results of isolations were analyzed by high performance liquid chromatographic (HPLC) and LC-MS/MS. Analysis of catechins by HPLC was done by external standard. Results: Fraction from 10% ethanol showed that four major peaks at retention time of 1.663, 2.367, 2.950 and 4.890, indicated the presence of four catechins components including catechin, epicatechins, gallocatechin and epigallocatechin. Whereas, fraction from 95% ethanol showed two main peaks at retention time of 5.167 and 9.82, which indicated the presence of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). EGCG (m/z 459), epigallocatechin (m/z 307), ECG (m/z 443), and epicatechin (m/z 291) were isolated and separated successfully using HPLC and LC-MS/MS. Conclusions: The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG. Four major catechins were separated and identified by LC-MS/MS, such as EGCG, epigallocatechin, ECG and epicatechin. The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.

  12. Qualitative analysis of catechins from green tea GMB-4 clone using HPLC and LC-MS/MS

    Institute of Scientific and Technical Information of China (English)

    Erna; Susanti; Ciptati; Retty; Ratnawati; Aulanni’am; Achmad; Rudijanto

    2015-01-01

    Objective:To identify the bioactive compounds in catechins isolation and its components from green tea GMB-4 clone.Methods:Green tea GMB-4 clones were extracted with distilled water at 90C.Samples were eluted into the column with 10%ethanol.Subsequently,the column was eluted with95%ethanol and evaporated separately.Green tea extract was identified by thin layer chromatography.Catechins were separated by the stationary phase in column chromatography using polyamide with 10%ethanol eluent and 95%ethanol.The results of isolations were analyzed by high performance liquid chromatographic(HPLC)and LCMS/MS.Analysis of catechins by HPLC was done by external standard.Results:Fraction from 10%ethanol showed that four major peaks at retention time of1.663,2.367,2.950 and 4.890,indicated the presence of four catechins components including catechin,epicatechins,gallocatechin and epigallocatechin.Whereas,fraction from 95%ethanol showed two main peaks at retention time of 5.167 and 9.82,which indicated the presence of epigallocatechin gallate(EGCG)and epicatechin gallate(ECG).EGCG(m/z 459),epigallocatechin(m/z 307),ECG(m/z 443),and epicatechin(m/z 291)were isolated and separated successfully using HPLC and LC-MS/MS.Conclusions:The HPLC and LC-MS/MS methods were successfully tuned for the qualitative analysis of green tea extract with EGCG and ECG.Four major catechins were separated and identified by LC-MS/MS,such as EGCG,epigallocatechin,ECG and epicatechin.The result of HPLC analysis showed that EGCG and ECG were main components from catechins isolation of green tea GMB-4 clone.

  13. 草麻黄根的黄酮类成分研究%Flavonoids from roots of Ephedra sinica

    Institute of Scientific and Technical Information of China (English)

    陶华明; 朱全红; 刘永宏

    2011-01-01

    目的:研究麻黄属植物草麻黄Ephedrasinica根的黄酮类化学成分.方法:草麻黄根用90%乙醇加热回流提取,采用硅胶、SephadexLH-20、RP-18柱色谱进行分离纯化,通过波谱分析(MS、1H-NMR、13C-NMR)鉴定结构.结果:从草麻黄根的醇提物的醋酸乙酯部分分离得到13个黄酮类化合物,分别鉴定为:麻黄根素A(1)、麻黄宁A(2)、麻黄宁B(3)、麻黄宁D(4)、芹菜素(5)、山柰酚(6)、槲皮素(7)、二氢槲皮素(8)、3',4',5,7-四羟基二氢黄酮(9)、儿茶素(10)、表儿茶素(11)、阿夫儿茶精(12)、表阿夫儿茶精(13).结论:化合物7~13为首次从该植物中分离得到.%Objective To study the flavonoids from the roots of Ephedra sinica in Ephedra Toum. Ex L. Methods The roots of E. Sinica were extracted with 90% ethanol, and isolated and purified by silica gel, Sephadex LH-20, and RP-18 gel column chromatography. All the compounds were identified based on spectral analyses (including MS, 'H-NMR, and 13C-NMR). Results Thirteen flavonoids were isolated from the roots of E. Sinica and were characterized as ephedrannin A (1), mahuannin A (2), mahuannin B (3), mahuannin D (4), apigenin (5), kaempferol (6), quercetin (7), dihydroquercetin (8), 3', 4', 5, 7-tetrahydroxy flavanone (9), (+)-catechin (10), (-)-epi-catechin (11), afzelechin (12), and (-)-epi-afzelechin (13), respectively. Conclusion Compounds 7-13 are obtained from this plant for the first time.

  14. Bioavailability, metabolism and potential health protective effects of dietary flavonoids

    DEFF Research Database (Denmark)

    Bredsdorff, Lea

    the association between exposure to dietary flavonoids and the risk of acute coronary syndrome (ACS) in a nested case-control study. The bioavailability and metabolism of hesperetin and naringenin was investigated by analysing urine and plasma from 16 subjects after consumption of three treatments of orange juice...... epidemiological studies but the evidence is inconclusive. One major obstacle for epidemiological studies investigating associations between flavonoid intake and risk of CHD is the estimation of flavonoid intake. There is a vast variety of flavonoids in commonly eaten food products but only limited knowledge...... of their content. In addition, variation in individual metabolic genotype and microflora may greatly affect the actual flavonoid exposure. The preventive effects of flavonoids on CHD are mainly ascribed to their anti-inflammatory and antioxidant activities. Several mechanisms of anti-inflammatory and antioxidant...

  15. Evaluation of Antioxidant Compounds and Total Sugar Content in a Nectarine [Prunus persica (L. Batsch] Progeny

    Directory of Open Access Journals (Sweden)

    Yolanda Gogorcena

    2011-10-01

    Full Text Available Epidemiological studies suggest that consumption of fruit rich in phenolic compounds is associated with health-protective effects due to their antioxidant properties. For these reasons quality evaluation has become an important issue in fruit industry and in breeding programs. Phytochemical traits such as total phenolics, flavonoids, anthocyanins, L-ascorbic acid, sugar content and relative antioxidant capacity (RAC were analyzed over four years in flesh fruit of an F1 population “Venus” × “Big Top” nectarines. Other traits such as harvesting date, yield, fruit weight, firmness, soluble solids concentration (SSC, pH, titratable acidity (TA and ripening index (RI were also determined in the progeny. Results showed high variability among genotypes for all analyzed traits. Total phenolics and flavonoids showed significant positive correlations with RAC implying that both are important antioxidant bioactive compounds in peaches. We found genotypes with enhanced antioxidant capacity and a better performance than progenitors, and in consequence the best marketability.

  16. Maturation of sugar maple seed

    Science.gov (United States)

    Clayton M., Jr. Carl; Albert G., Jr. Snow; Albert G. Snow

    1971-01-01

    The seeds of a sugar maple tree (Acer saccharum Marsh.) do not mature at the same time every year. And different trees mature their seeds at different times. So time of year is not a reliable measure of when seeds are ripe. Better criteria are needed. In recent studies we have found that moisture content and color are the best criteria for judging when sugar maple...

  17. Chemistry and Biological Activities of Flavonoids: An Overview

    OpenAIRE

    Shashank Kumar; Pandey, Abhay K

    2013-01-01

    There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about...

  18. Total Phenolics and Total Flavonoids in Selected Indian Medicinal Plants

    OpenAIRE

    C T Sulaiman; Indira Balachandran

    2012-01-01

    Plant phenolics and flavonoids have a powerful biological activity, which outlines the necessity of their determination. The phenolics and flavonoids content of 20 medicinal plants were determined in the present investigation. The phenolic content was determined by using Folin-Ciocalteu assay. The total flavonoids were measured spectrophotometrically by using the aluminium chloride colorimetric assay. The results showed that the family Mimosaceae is the richest source of phenolics, (Acacia ni...

  19. Assessment of Flavonoid Release with Different Permeation Enhancers

    OpenAIRE

    Vaisakh M N; Pandey A

    2012-01-01

    The aim of the study was to evaluate the effect of different permeation enhancers in the transdermal permeation of flavonoids. A weed plant named Chromolaena odorata have been employed as the flavonoid source. Six different cream formulations have been prepared with the Chromolaena extract using different permeation enhancers such as ethanol, dimethyl sulphoxide, surfactants and occlusive agents. The amount of flavonoids penetrated during a time period of four hours was noted. The highest amo...

  20. Isolation, purification and identification of ellagic acid derivatives, catechins, and procyanidins from the root bark of Anisophyllea dichostyla R. Br.

    Science.gov (United States)

    Khallouki, F; Haubner, R; Hull, W E; Erben, G; Spiegelhalder, B; Bartsch, H; Owen, R W

    2007-03-01

    The root bark of Anisophyllea dichostyla R. Br. is traditionally used in the Democratic Republic Congo for the treatment of several conditions such as anorexia, fatigue and intestinal infections. We have identified and quantitated several polyphenol antioxidants in the methanol extract of the root bark (120g). The polyphenol content (3.32g/kg) was predominantly ellagitannins (25%) and polyhydroxyflavan-3-ols (catechins and procyanidins, 75%) with 3'-O-methyl-3,4-methylenedioxo ellagic acid 4'-O-beta-d-glucopyranoside and (-)-epicatechin as the major species in each class. These two compounds and the following species were identified unequivocally by NMR spectroscopy: (+)-catechin, (-)-epicatechin 3-O-gallate, 3-O-methyl ellagic acid, 3,3'-di-O-methyl ellagic acid, 3'-O-methyl-3,4-methylenedioxo ellagic acid, 3'-O-methyl-3,4-methylenedioxo ellagic acid 4'-O-beta-d-glucopyranoside, and 3'-O-methyl ellagic acid 4-O-beta-d-xylopyranoside. The following additional compounds were purified by semi-preparative HPLC and tentatively identified on the basis of UV spectra, HPLC-ESI-MS and nano-ESI-MS-MS: (+)-catechin-3-O-beta-d-glucopyranoside, epicatechin-(4beta-->8)-catechin (procyanidin B(1)), epicatechin-(4beta-->8)-epicatechin (procyanidin B(2)), an (epi)catechin trimer, 3-O-methyl ellagic acid 4-O-beta-d-glucopyranoside, (-)-epicatechin 3-O-vanillate, 3,4-methylenedioxo ellagic acid 4'-O- beta-d-glucopyranoside, and 3,3'-di-O-methyl ellagic acid 4-O-beta-d-xylopyranoside. Fractionation of the raw extract by column chromatography on silicic acid yielded 10 fractions. In the hypoxanthine/xanthine oxidase antioxidant assay system, CC-9 which contained a range of polyphenols dominated by (-)-epicatechin-O-gallate proved to be the most potent antioxidant fraction (IC(50)=52 micro g/mL) in terms of ROS scavenging. In terms of XO inhibition CC-8, dominated by (epi)catechin trimer and which also contained appreciable amounts of 3'-O-methyl ellagic acid 4'-O

  1. Dietary flavonoids and gastric cancer risk in a Korean population.

    Science.gov (United States)

    Woo, Hae Dong; Lee, Jeonghee; Choi, Il Ju; Kim, Chan Gyoo; Lee, Jong Yeul; Kwon, Oran; Kim, Jeongseon

    2014-11-10

    Gastric cancer is the most common cancer among men in Korea, and dietary factors are closely associated with gastric cancer risk. We performed a case-control study using 334 cases and 334 matched controls aged 35-75 years. Significant associations were observed in total dietary flavonoids and their subclasses, with the exception of anthocyanidins and isoflavones (OR (95% CI): 0.49 (0.31-0.76), p trend = 0.007 for total flavonoids). However, these associations were not significant after further adjustment for fruits and vegetable consumption (OR (95% CI): 0.62 (0.36-1.09), p trend = 0.458 for total flavonoids). Total flavonoids and their subclasses, except for isoflavones, were significantly associated with a reduced risk gastric cancer in women (OR (95% CI): 0.33 (0.15-0.73), p trend = 0.001 for total flavonoids) but not in men (OR (95% CI): 0.70 (0.39-1.24), p trend = 0.393 for total flavonoids). A significant inverse association with gastric cancer risk was observed in flavones, even after additional adjustment for fruits and vegetable consumption in women. No significantly different effects of flavonoids were observed between H. pylori-positive and negative subjects. In conclusion, dietary flavonoids were inversely associated with gastric cancer risk, and these protective effects of dietary flavonoids were prominent in women. No clear differences were observed in the subgroup analysis of H. pylori and smoking status.

  2. Life Cycle Assessment of Sugar Production (VB)

    DEFF Research Database (Denmark)

    Teljigovic, Mehmed; Mengiardi, Jon; Factor, Gabriela

    1999-01-01

    will be made between sugar from sugar beet produced in Denmark versus sugar produces from sugar cane in a tropical country, Brazil, and transported afterwards to Denmark. To evaluate the environmental aspects of these two product systems a Life Cycle Assessement (LCA) will be carried out.From the results...

  3. Positive allosteric modulation of the GHB high-affinity binding site by the GABAA receptor modulator monastrol and the flavonoid catechin

    DEFF Research Database (Denmark)

    Eghorn, Laura Friis; Høstgaard-Jensen, Kirsten; Kongstad, Kenneth Thermann

    2014-01-01

    conformational changes in the binding site, demonstrating a positive allosteric modulation of radioligand binding. Surprisingly, binding of [3H]GHB and the GHB high-affinity site-specific radioligands [125I]BnOPh-GHB and [3H]HOCPCA was either decreased or only weakly increased, indicating that the observed......γ-Hydroxybutyric acid (GHB) is a metabolite of γ-aminobutyric acid (GABA) and a proposed neurotransmitter in the mammalian brain. We recently identified α4βδ GABAA receptors as possible high-affinity GHB targets. GABAA receptors are highly sensitive to allosteric modulation. Thus to investigate...... whether GHB high-affinity binding sites are also sensitive to allosteric modulation, we screened both known GABAA receptor ligands and a library of natural compounds in the rat cortical membrane GHB specific high-affinity [3H]NCS-382 binding assay. Two hits were identified: Monastrol, a positive...

  4. Adsorption kinetics of tea waste to catechins%茶渣对儿茶素的吸附动力学

    Institute of Scientific and Technical Information of China (English)

    胡书琴; 汤一; 刘莉

    2014-01-01

    Summary Catechins , the main functional components in tea , were generally recognized as possessing desirable biological and physiological effects , such as anti‐oxidation , anti‐cancer , reducing the risk of cardiovascular diseases etc . Therefore , application areas of tea catechins in food and pharmaceuticals were expanding rapidly . At present , conventional extraction technologies of catechins contained hot water extraction method , organic solvent extraction process , resin extraction method and supercritical CO 2 extraction method . However , the application value was limited because of the low efficiency , high cost and potentially toxic residues . In order to extract catechins efficiently and safely , the recent studies found that lignocellulose could absorb catechins in abundance and in a low cost . Tea waste was used as a new kind of adsorbent in this paper . Because of the porous structure , it had large specific surface area . Meanwhile , the main components of tea waste were cellulose and protein . They all contained a mass of carboxyl groups and hydroxyl radicals which could form hydrogen bonds with catechins . The tea waste was similar to lignocellulose in structure and it was eatable , safe with no poisonous residue .The experiments were carried out as below . The equations of pseudo‐first‐order model and pseudo‐second‐order model were used to simulate the adsorption kinetics respectively . Then , different concentrations of ethanol were used to desorb the tea waste when it reached adsorption saturation . Finally , the same size tea waste was used to pack the chromatography column and the breakthrough curves of catechins and caffeine were drawn , then different concentrations of ethanol were used to elute the column gradely when it reached adsorption equilibrium . The results indicated that the kinetics were more fitted to the pseudo‐second‐order model ( R2 = 0 .913 6 0 .997 1) . The order of the secondary adsorption speed constant

  5. Molecular Docking Studies of Catechin and Its Derivatives as Anti-bacterial Inhibitor for Glucosamine-6-Phosphate Synthase

    Science.gov (United States)

    Fikrika, H.; Ambarsari, L.; Sumaryada, T.

    2016-01-01

    Molecular docking simulation of catechin and its derivatives on Glucosamine-6- Phosphate Synthase (GlmS) has been performed in this research. GlmS inhibition by a particular ligand will suppress the production of bacterial cell wall and significantly reduce the population of invading bacteria. In this study, catechin derivatives i.e epicatechin, galloatechin and epigalloatechin were found to have stronger binding affinities as compared to natural ligand of GlmS, Fructose-6-Phosphate (F6P). Those three ligands were docked on the same pocket in GlmS target as F6P, with 70% binding sites similarity. Based on the docking results, gallocatechin turns out to be the most potent ligand for anti-bacterial agent with ΔG= -8.00 kcal/mol. The docking between GlmS and catechin derivatives are characterized by a constant present of a strong hydrogen bond between functional group O3 and Ser-349. This hydrogen bond most likely plays a significant role in the docking mechanism and binding modes selection. The surprising result is catechin itself exhibited a quite strong binding with GlmS (ΔG= -7.80 kcal.mol), but docked on a completely different pocket compared to other ligands. This results suggest that catechin might still have a curing effect but with a completely different pathway and mechanism as compared to its derivatives.

  6. Inhibition of pro-/active MMP-2 by green tea catechins and prediction of their interaction by molecular docking studies.

    Science.gov (United States)

    Chowdhury, Animesh; Nandy, Suman Kumar; Sarkar, Jaganmay; Chakraborti, Tapati; Chakraborti, Sajal

    2017-03-01

    Matrix metalloproteinases (MMPs) play a crucial role in developing different types of lung diseases, e.g., pulmonary arterial hypertension (PAH). Green tea polyphenolic catechins such as EGCG and ECG have been shown to ameliorate various types of diseases including PAH. Our present study revealed that among the four green tea catechins (EGCG, ECG, EC, and EGC), EGCG and ECG inhibit pro-/active MMP-2 activities in pulmonary artery smooth muscle cell (PASMC) culture supernatant. Based on the above, we investigated the interactions of pro-/active MMP-2 with the green tea catechins by computational methods. In silico analysis revealed a strong interaction of pro-/active MMP-2 with EGCG/ECG, and galloyl group has been observed to be responsible for this interaction. The in silico analysis corroborated our experimental observation that EGCG and ECG are active in preventing both the proMMP-2 and MMP-2 activities. Importantly, these two catechins appeared to be better inhibitors for proMMP-2 in comparison to MMP-2 as revealed by gelatin zymogram and also by molecular docking studies. In many type of cells, activation of proMMP-2 occurs via an increase in the level of MT1-MMP (MMP-14). We, therefore, determined the interactions of MT1-MMP with the green tea catechins by molecular docking analysis. The study revealed a strong interaction of MT1-MMP with EGCG/ECG, and galloyl group has been observed to be responsible for the interaction.

  7. Acute ingestion of catechin-rich green tea improves postprandial glucose status and increases serum thioredoxin concentrations in postmenopausal women.

    Science.gov (United States)

    Takahashi, Masaki; Miyashita, Masashi; Suzuki, Katsuhiko; Bae, Seong-Ryu; Kim, Hyeon-Ki; Wakisaka, Takuya; Matsui, Yuji; Takeshita, Masao; Yasunaga, Koichi

    2014-11-14

    Elevated postprandial hyperglycaemia and oxidative stress increase the risks of type 2 diabetes and CVD. Green tea catechin possesses antidiabetic properties and antioxidant capacity. In the present study, we examined the acute and continuous effects of ingestion of catechin-rich green tea on postprandial hyperglycaemia and oxidative stress in healthy postmenopausal women. Participants were randomly assigned into the placebo (P, n 11) or green tea (GT, n 11) group. The GT group consumed a catechin-rich green tea (catechins 615 mg/350 ml) beverage per d for 4 weeks. The P group consumed a placebo (catechins 92 mg/350 ml) beverage per d for 4 weeks. At baseline and after 4 weeks, participants of each group consumed their designated beverages with breakfast and consumed lunch 3 h after breakfast. Venous blood samples were collected in the fasted state (0 h) and at 2, 4 and 6 h after breakfast. Postprandial glucose concentrations were 3 % lower in the GT group than in the P group (three-factor ANOVA, group × time interaction, Pcatechin-rich green tea intake was observed. Conversely, serum postprandial thioredoxin concentrations were 5 % higher in the GT group than in the P group (three-factor ANOVA, group × time interaction, Pcatechin-rich green tea has beneficial effects on postprandial glucose and redox homeostasis in postmenopausal women.

  8. Correlation between catechin content and NF-κB inhibition by infusions of green and black tea.

    Science.gov (United States)

    Di Lorenzo, Chiara; Dell'Agli, Mario; Sangiovanni, Enrico; Dos Santos, Ariana; Uberti, Francesca; Moro, Enzo; Bosisio, Enrica; Restani, Patrizia

    2013-06-01

    This study investigates whether infusions of green and black tea inhibit the NF-κB driven transcription in human epithelial gastric AGS cells. Water extracts were prepared from different brands of green and black tea available on the Italian market. Teas with or without caffeine were studied. An industrially prepared freeze-dried water extract of green tea was also tested. Catechin and caffeine contents were measured by HPLC analysis. The decrease in phenol and catechin content three months after the expiry date was also investigated. The NF-κB driven transcription and the free radical scavenger activity were inhibited, and this effect was related to catechin levels. The potency of epigallocatechin 3-gallate in inhibiting NF-κB driven transcription is so great that tea extracts low in epigallocatechin 3-gallate are still highly active. In one decaffeinated sample of green tea, the phenol and catechin content was very low, probably as a consequence of caffeine removal. The decrease in catechin levels after 3 months did not reduce the inhibition of NF-κB driven transcription by tea infusions. This is the first paper reporting the inhibitory effect of NF-κB of commercial green and black infusions at the gastric level, evaluating their stability as well.

  9. A novel functional full-fat hard cheese containing liposomal nanoencapsulated green tea catechins: manufacture and recovery following simulated digestion.

    Science.gov (United States)

    Rashidinejad, Ali; Birch, E John; Everett, David W

    2016-07-13

    (+)-Catechin or green tea extract were encapsulated in soy lecithin nanoliposomes and incorporated into a full-fat cheese, then ripened at 8 °C for 90 days. Cheese samples were subjected to simulated gastrointestinal digestion to measure total phenolic content (TPC) and antioxidant activity of the cheese digesta, and to determine the catechin recovery after digestion by high performance liquid chromatography (HPLC). Addition of catechin or green tea extract significantly (P ≤ 0.05) increased TPC and antioxidant activity (measured by ferric reducing antioxidant power and oxygen radical absorbance capacity) of the full-fat cheese without affecting pH or proximate composition. HPLC analysis confirmed retention of encapsulated catechins in the cheese curd; however, individual catechins were recovered in differing amounts (15-52%) from cheese digesta after 6 h of digestion. Transmission electron microscopy and Fourier transform infrared spectroscopy provided evidence for association of nanoliposomes with the surface of milk fat globules inside the cheese matrix. The study shows the potential for using cheese as a delivery vehicle for green tea antioxidants.

  10. The water footprint of sweeteners and bio-ethanol from sugar cane, sugar beet and maize

    NARCIS (Netherlands)

    Gerbens-Leenes, Winnie; Hoekstra, Arjen Ysbert

    2009-01-01

    Sugar cane and sugar beet are used for sugar for human consumption. In the US, maize is used, amongst others, for the sweetener High Fructose Maize Syrup (HFMS). Sugar cane, sugar beet and maize are also important for bio-ethanol production. The growth of crops requires water, a scarce resource. The

  11. 76 FR 36512 - USDA Increases the Domestic Sugar Overall Allotment Quantity, Reassigns Domestic Cane Sugar...

    Science.gov (United States)

    2011-06-22

    ... Office of the Secretary USDA Increases the Domestic Sugar Overall Allotment Quantity, Reassigns Domestic Cane Sugar Allotments, and Increases the Fiscal Year 2011 Raw Sugar Tariff-Rate Quota AGENCY: Office of... in the domestic sugar Overall Allotment Quantity (OAQ); a reassignment of surplus sugar under...

  12. The water footprint of sweeteners and bio-ethanol from sugar cane, sugar beet and maize

    NARCIS (Netherlands)

    Gerbens-Leenes, P.W.; Hoekstra, A.Y.

    2009-01-01

    Sugar cane and sugar beet are used for sugar for human consumption. In the US, maize is used, amongst others, for the sweetener High Fructose Maize Syrup (HFMS). Sugar cane, sugar beet and maize are also important for bio-ethanol production. The growth of crops requires water, a scarce resource. The

  13. In vitro bioavailability and cellular bioactivity studies of flavonoids and flavonoid-rich plant extracts: questions, considerations and future perspectives.

    Science.gov (United States)

    Gonzales, Gerard Bryan

    2017-08-01

    In vitro techniques are essential in elucidating biochemical mechanisms and for screening a wide range of possible bioactive candidates. The number of papers published reporting in vitro bioavailability and bioactivity of flavonoids and flavonoid-rich plant extracts is numerous and still increasing. However, even with the present knowledge on the bioavailability and metabolism of flavonoids after oral ingestion, certain inaccuracies still persist in the literature, such as the use of plant extracts to study bioactivity towards vascular cells. There is therefore a need to revisit, even question, these approaches in terms of their biological relevance. In this review, the bioavailability of flavonoid glycosides, the use of cell models for intestinal absorption and the use of flavonoid aglycones and flavonoid-rich plant extracts in in vitro bioactivity studies will be discussed. Here, we focus on the limitations of current in vitro systems and revisit the validity of some in vitro approaches, and not on the detailed mechanism of flavonoid absorption and bioactivity. Based on the results in the review, there is an apparent need for stricter guidelines on publishing data on in vitro data relating to the bioavailability and bioactivity of flavonoids and flavonoid-rich plant extracts.

  14. Sugar substitutes: Health controversy over perceived benefits

    OpenAIRE

    Tandel, Kirtida R.

    2011-01-01

    Sugar is an inseparable part of the food we consume. But too much sugar is not ideal for our teeth and waistline. There have been some controversial suggestions that excessive sugar may play an important role in certain degenerative diseases. So artificial sweeteners or artificially sweetened products continue to attract consumers. A sugar substitute (artificial sweetener) is a food additive that duplicates the effect of sugar in taste, but usually has less food energy. Besides its benefits, ...

  15. Optimal concentration for sugar transport in plants

    OpenAIRE

    Jensen, Kaare H; Savage, Jessica A; Holbrook, N. Michele

    2013-01-01

    Vascular plants transport energy in the form of sugars from the leaves where they are produced to sites of active growth. The mass flow of sugars through the phloem vascular system is determined by the sap flow rate and the sugar concentration. If the concentration is low, little energy is transferred from source to sink. If it is too high, sap viscosity impedes flow. An interesting question is therefore at which concentration is the sugar flow optimal. Optimization of sugar flow and transpor...

  16. Inverse association of tea and flavonoid intakes with incident myocardial infarction: the Rotterdam Study

    NARCIS (Netherlands)

    J.M. Geleijnse (Marianne); L.J. Launer (Lenore); D.A. van der Kuip (Deirdre); J.C.M. Witteman (Jacqueline); A. Hofman (Albert)

    2002-01-01

    textabstractBACKGROUND: Dietary flavonoids may protect against cardiovascular disease, but evidence is still conflicting. Tea is the major source of flavonoids in Western populations. OBJECTIVE: The association of tea and flavonoid intake with incident myocardial infarction was

  17. Inverse association of tea and flavonoid intakes with incident myocardial infarction: the Rotterdam Study

    NARCIS (Netherlands)

    J.M. Geleijnse (Marianne); L.J. Launer (Lenore); D.A. van der Kuip (Deirdre); J.C.M. Witteman (Jacqueline); A. Hofman (Albert)

    2002-01-01

    textabstractBACKGROUND: Dietary flavonoids may protect against cardiovascular disease, but evidence is still conflicting. Tea is the major source of flavonoids in Western populations. OBJECTIVE: The association of tea and flavonoid intake with incident myocardial infarction was exa

  18. Combined Autodock and comparative molecular field analysis study on predicting 5-lipoxygenase inhibitory activity of flavonoids isolated from Spatholobus suberectus Dunn.

    Science.gov (United States)

    Jiang, Shiyun; Huang, Kai; Liu, Wen; Fu, Fengming; Xu, Jie

    2015-01-01

    5-Lipoxygenase (5-LOX) plays a key role in the pathway of leukotriene biosynthesis. To predict the inhibitory activity of flavonoid inhibitors against 5-LOX from Spatholobus suberectus Dunn, Autodock 4.2 and comparative molecular field analysis (CoMFA) were employed. For the positive inhibitors (n=7), the value of the coefficient of determination (R2) between the binding free energy, calculated using Autodock 4.2, and the experimental pIC50 is 0.838. In the training set (n=21) of inhibitors against 5-LOX, the R2 of non-cross-validated partial least squares analysis between the actual and predicted pIC50 values, using the no-validation with the optimum number of components set to 6, is 0.997 (p=0.000). For the model generated by CoMFA, the contribution of electrostatic and steric factors are 0.522 and 0.478, respectively. Among the flavonoids of S. suberectus, liquiritigenin, catechin, butin, 3',4',7-trihydroxyflavone, plathymenin, and gallocatechin are the more potent inhibitors of 5-LOX based on the calculated binding free energy and the predicted pIC50 value.

  19. Flavonoid compounds from the red marine alga Alsidium corallinum protect against potassium bromate-induced nephrotoxicity in adult mice.

    Science.gov (United States)

    Ben Saad, Hajer; Gargouri, Manel; Kallel, Fatma; Chaabene, Rim; Boudawara, Tahia; Jamoussi, Kamel; Magné, Christian; Mounir Zeghal, Khaled; Hakim, Ahmed; Ben Amara, Ibtissem

    2017-05-01

    Potassium bromate (KBrO3 ), an environmental pollutant, is a well-known human carcinogen and a potent nephrotoxic agent. Currently, natural products have built a well-recognized role in the management of many diseases induced by pollutants. As potent natural sources of bioactive compounds, marine algae have been demonstrated to be rich in novel secondary metabolites with a broad range of biological functions. In this study, adults male mice were orally treated for 15 days with KBrO3 (0.5 g/L) associated or not with extract of Alsidium corallinum, a red Mediterranean alga. In vitro study demonstrated that algal extract has antioxidant efficacy attributable to the presence of flavonoids and polyphenols. Among these, Liquid chromatography-mass spectrometry analysis showed A. corallinum is rich in kaempferol, apigenin, catechin, and quercetin flavonoids. In vivo study showed that supplementation with the alga significantly prevented KBrO3 -induced nephrotoxicity as indicated by plasma biomarkers (urea, uric acid, and creatinin levels) and oxidative stress related parameters (malondialdehyde, superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, vitamin C, hydrogen peroxide, protein oxidation products) in kidney tissue. The corrective effect of A. corallinum on KBrO3 -induced kidney injury was also supported by molecular and histopathological observations. In conclusion, it was established that the red alga, thanks to its bioactive compounds, effectively counteracts toxic effects of KBrO3 and could be a useful coadjuvant agent for treatment of this pollutant poisonings. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1475-1486, 2017. © 2016 Wiley Periodicals, Inc.

  20. Mechanisms of carcinogenesis prevention by flavonoids

    Directory of Open Access Journals (Sweden)

    G. A. Belitsky

    2014-01-01

    Full Text Available The mechanisms of anticancerogenic effects of flavanoids and isocyanates from the plants widely consumed in the midland belt of Russia were reviewed. Data of studies both in vitro and in vivo were analyzed. Special attention was paid to inhibition of targets responsible for carcinogen metabolic activation, carcinogenesis promotion and tumor progression as well as neoangiogenesis. Besides that the antioxidant properties of flavonoids and their effects on cell cycle regulation, apoptosis initiation and cell mobility were considered.

  1. Two new flavonoid diglycosides from Cephalotaxus sinensis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two new acetylated flavonoid diglycosides, scutellarein-5-O-[α-L-rhamnopyranosyl-(1 → 4)-β-D-6-O-acetylglucopyranoside](1), apigenin-5-O-[α-L-rhamnopyranosyl-(1→ 2)-β-D-3,6-di-O-acetylglucopyranoside] (2), were isolated from the leaves of Cephalotaxus sinensis. Their structures were determined by chemical and spectroscopic methods including HR-FAB-MS,1H-1H COSY, HSQC and HMBC experiments.(C) 2007 Yu Hong Yu. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

  2. Chromone and Flavonoid Alkaloids: Occurrence and Bioactivity

    Directory of Open Access Journals (Sweden)

    Robin J. Marles

    2011-12-01

    Full Text Available The chromone and flavonoid alkaloids represent an unusual group of structurally diverse secondary metabolites, derived from the convergence of multiple biosynthetic pathways that are widely distributed through the plant and animal kingdoms. Many of them have been discovered through bioassay-guided chemical investigations of traditional medicines, suggesting potential therapeutic significance. Their unique structures and varied pharmacological activities may provide important new leads for the discovery of drugs with novel mechanisms of action. Potential therapeutic indications are as diverse as cancer and viral infections, inflammation and immunomodulation, neurological and psychiatric conditions, and diabetes.

  3. Flavonoides e sesquiterpenos de Croton pedicellatus Kunth

    Directory of Open Access Journals (Sweden)

    Elton Luz Lopes

    2012-01-01

    Full Text Available The chemical investigation of the ethanolic extract from leaves of Croton pedicellatus yielded the bis-nor-sesquiterpenes blumenol A and blumenol A glucoside, along with the flavonoids: tiliroside, 6"-O-p-coumaroyl-β-galactopyranosyl- kaempferol, 6"-O-p-coumaroyl-β-glucopyranosyl-3"-methoxy- kaempferol, kaempferol, 3-glucopyranosyl-quercetin and alpinumisoflavone, as well as 4-hydroxy-3,5-dimethoxybenzoic acid. The identification of all isolated compounds was performed by spectrometric methods, including HR-ESI-MS, 1D and 2D NMR experiments, and by comparison with previously-described physical and spectral data.

  4. Estrogenic flavonoids: structural requirements for biological activity.

    Science.gov (United States)

    Miksicek, R J

    1995-01-01

    A systematic survey of polycyclic phenols has been performed to identify members of this chemical group with estrogenic activity. Twelve compounds were found to be able to stimulate the transcriptional activity of the human estrogen receptor expressed in cultured cells by transient transfection. These natural estrogens belong to several distinct, but chemically related classes including chalcones, flavanones, flavones, flavonols, and isoflavones. Selected examples of estrogenic flavonoids were further analyzed to determine their biological potencies and their relative affinities for binding to the estrogen receptor. These data are interpreted with respect to the molecular structure of polycyclic phenols required for hormonal activity as nonsteroidal estrogens.

  5. Methylxanthine and catechin content of fresh and fermented cocoa beans, dried cocoa beans, and cocoa liquor

    Directory of Open Access Journals (Sweden)

    Pedro P. Peláez

    2016-01-01

    Full Text Available The theobromine and catechin content can affect the quality of cocoa liquor and is influenced by cacao variety, production area (PA, and fermentation, as well as the method of drying beans (FDB and cocoa liquor production (CLP. This study examined variationsin methylxanthine and catechin levels in fresh and fermented cocoa beans, dried cocoa grains, and in cocoa liquor from Trinitario, Criollo, and Forastero cacao varieties. A total of 123 cocoa bean samples from three Peruvian PAs at different altitudes, Tingo María (TM, San Alejandro (SA, and Curimana (CU, were evaluated. The theobromine (Tb and caffeine (Cf contents in fresh cocoa beans were affected by both cocoa type and PA. The caffeine content was higher in Trinitario cacao than in Criollo and Forastero varieties (p ≤ 0.05. The Tb and CF contents decreased in dry cocoa grain and was affected by FDB (p ≤ 0.05 (1.449 ± 0.004 to 1.140 ± 0.010 and 0.410 ± 0.03 to 0.165 ± 0.02 g Tb and C, respectively, per 100 g dry weight. Cocoa beans from Tingo María, which has thehighest altitude, had higher Tb and CF contents than those from other PAs. The catechin (C and epicatechin (EC contents were affected by the FDB and CLP, and were highestin fresh cocoa beans from the Tingo María area (range: 0.065 ± 0.01 to 0.020 ± 0.00 g C/100 g. The C and EC contents decreased during FDB and CLP (0.001 g C/100 g of cocoa liquor. Taken together, these results show that higher concentrations of Tb, Cf, C,and EC are present in fresh cocoa beans. Moreover, the cocoa variety influenced cocoa liquor quality. Overall, cocoa from the Tingo María PA had the most desirable chemical composition.

  6. Eco-friendly separation of catechins using cyclodextrins as mobile phase additives in RP-HPLC.

    Science.gov (United States)

    Bi, Wentao; Li, Shengnan; Row, Kyung Ho

    2012-01-01

    New mobile phases for RP-HPLC were developed for the separation of catechin compounds in tea. Cyclodextrin mobile phase additives decreased the use of toxic and inflammable organic solvents without compromising resolution or separation efficiency. To develop a simple greener method for analyzing five tea catechins in RP-HPLC, the mobile phase condition was optimized and the lowest organic modifier proportion with content resolutions and retention factors were obtained. Eco-friendly cyclodextrins were used as mobile phase additives to decrease the proportion of organic modifier and improve resolutions and retention factors. The effects of several physico-chemical parameters on the retention factors were investigate d and the optimum conditions were obtained on a conventional C₁₈ column, where the mobile phase consisted of acetonitrile/water (12/88, v/v) with 1.5 mmol/L β-cyclodextrin at a flow rate of 1.0 mL/min. Cyclodextrins can separate analytes through host-guest complexation, where a transient diastereomeric complex is formed between the cyclodextrin and the analyte. β-Cyclodextrin is the most accessible, the least expensive and generally the most useful cyclodextrin. This work developed a simple eco-friendly method with the lowest concentration of organic solvents. Under the optimal condition, five catechins could be baseline separated within 17 minutes in the isocratic mode. This research exhibited the potential for the separation and determination of other active compounds from natural plants by a greener method. Copyright © 2011 John Wiley & Sons, Ltd.

  7. Exploratory conformational study of (+)-catechin. Modeling of the polarizability and electric dipole moment.

    Science.gov (United States)

    Bentz, Erika N; Pomilio, Alicia B; Lobayan, Rosana M

    2014-12-01

    The extension of the study of the conformational space of the structure of (+)-catechin at the B3LYP/6-31G(d,p) level of theory is presented in this paper. (+)-Catechin belongs to the family of the flavan-3-ols, which is one of the five largest phenolic groups widely distributed in nature, and whose biological activity and pharmaceutical utility are related to the antioxidant activity due to their ability to scavenge free radicals. The effects of free rotation around all C-O bonds of the OH substituents at different rings are taken into account, obtaining as the most stable conformer, one that had not been previously reported. One hundred seven structures, and a study of the effects of charge delocalization and stereoelectronic effects at the B3LYP/6-311++G(d,p) level are reported by natural bond orbital analysis, streamlining the order of these structures. For further analysis of the structural and molecular properties of this compound in a biological environment, the calculation of polarizabilities, and the study of the electric dipole moment are performed considering the whole conformational space described. The results are analyzed in terms of accumulated knowledge for (4α → 6″, 2α → O → 1″)-phenylflavans and (+)-catechin in previous works, enriching the study of both types of structures, and taking into account the importance of considering the whole conformational space in modeling both the polarizability and the electric dipole moment, also proposing to define a descriptive subspace of only 16 conformers.

  8. Methods for dehydration of sugars and sugar alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Holladay, Johnathan E [Kennewick, WA; Hu, Jianli [Kennewick, WA; Zhang, Xinjie [Burlington, MA; Wang, Yong [Richland, WA

    2010-08-10

    The invention includes a method of dehydration of a sugar using a dehydration catalyst and a co-catalyst within a reactor. A sugar is introduced and H.sub.2 is flowed through the reactor at a pressure of less than or equal to about 300 psig to convert at least some of the sugar into an anhydrosugar product. The invention includes a process for producing isosorbide. A starting material comprising sorbitol is flowed into a reactor. H.sub.2 is counter flowed through the reactor. The starting material is exposed to a catalyst in the presence of a co-catalyst which comprises at least one metal. The exposing is conducted at a hydrogen pressure of less than or equal to 300 psig within the reactor and the hydrogen removes at least some of any water present during the exposing and inhibits formation of colored byproducts.

  9. 绿茶胶囊对黑巧克力中表儿茶素和儿茶素在人体内生物利用率的影响%Effects of green tea capsules on human bioavailability of epicatechin and catechin from dark chocolate

    Institute of Scientific and Technical Information of China (English)

    蒋晗; Andrea Day

    2012-01-01

    以志愿者体内实验方式考察绿茶胶囊对黑巧克力中表儿茶素和儿茶素在人体内生物利用率的影响.六位志愿者在实验前一天严格执行低黄酮类饮食,空腹过夜并留下尿样作为空白样本.试验第一阶段:志愿者摄入50 g黑巧克力(含表儿茶素152 mg,儿茶素33mg).一周之后的第二阶段,志愿者摄入50 g黑巧克力和一片绿茶胶囊(绿茶胶囊含表儿茶素207mg,儿茶素39mg).服用后每间隔一定时间,收集志愿者尿样,测定表儿茶素和儿茶素的生物利用率.结果显示,虽然第二阶段的表儿茶素和儿茶素摄入总量均高于第一阶段,但两者在第一阶段人体中的生物利用率均高于第二阶段.因此和单独摄入黑巧克力相比,绿茶胶囊和黑巧克力同时服用可能会导致减少或者延迟人体对表儿茶素和儿茶素的吸收.%To compare the human bioavailability of epicatechin and catechin after intake of dark chocolate with or without a green tea capsule. Six volunteers followed a low-flavonoids diet 1 d before each phase of the study and underwent an overnight fast. In phase 1, they ingested 50 g of dark chocolate (epicatechin: 152 mg; catechin: 33 mg). After one week, subjects were fed 50 g dark chocolate along with a green tea capsule (epicatechin: 207 mg; catechin: 39 mg) as phase 2. Urine samples were collected over 3 time periods for detection of the human bioavailability of cepicatechin and catechin. Even though high amounts of epicatechin and catechin were ingested in phase 2, the human bioavailability of both epicatechin and catechin in phase 1 was higher than that in phase 2. Therefore the results suggests that green tea capsule co-ingestion with chocolate might result in a reduction or a possible delaying of epicatechin and catechin absorption compared with only intake of chocolate.

  10. Synthesis of modified proanthocyanidins: introduction of acyl substituents at C-8 of catechin. Selective synthesis of a C-4-->O-->C-3 ether-linked procyanidin-like dimer.

    Science.gov (United States)

    Beauhaire, Josiane; Es-Safi, Nour-Eddine; Boyer, François-Didier; Kerhoas, Lucien; Guernevé, Christine le; Ducrot, Paul-Henri

    2005-02-01

    The regioselective introduction of substituents at C-8 of (+)-catechin is described, leading to the synthesis of several catechin derivatives with various substitution patterns to be used for the further synthesis of modified proanthocyanidins. Thereafter, a new 3-O-4 ether-linked procyanidin-like derivative was synthesized. Its formation was selectively achieved through TiCl(4)-catalyzed condensation of 4-(2-hydroxyethoxy)tetra-O-benzyl catechin with the 8-trifluoroacetyl adduct of tetra-O-benzyl catechin.

  11. Green tea catechins for well-being and therapy: prospects and opportunities

    Directory of Open Access Journals (Sweden)

    Miyoshi N

    2015-12-01

    Full Text Available Noriyuki Miyoshi,1 Monira Pervin,1 Takuji Suzuki,2 Keiko Unno,3 Mamoru Isemura,1 Yoriyuki Nakamura1 1School of Food and Nutritional Sciences, University of Shizuoka, Yada, Shizuoka, Japan; 2Faculty of Education, Art and Science, Yamagata University, Yamagata, Japan; 3School of Pharmaceutical Sciences, University of Shizuoka, Yada, Shizuoka, Japan Abstract: Tea is derived from the leaves and buds of Camellia sinensis (Theaceae plant, and is consumed worldwide. Green tea was discovered in the People's Republic of China approximately 3,000 BC. Lu Yu (733–803 published a book that describes the history of tea, the techniques, and utensils used for manufacturing, the method of preparation, and drinking of tea in the People's Republic of China. Green tea contains various components with specific health-promoting effects and is believed to exert protective effects against diseases such as cancer, obesity, diabetes, hepatitis, and neurodegenerative diseases. Of the various tea components, the polyphenol catechins have been the subject of extensive investigation. Among the catechins, (--epigallocatechin gallate has the strongest bioactivity in most cases. Caffeine induces alertness, decreases the sensation of fatigue, and has a diuretic effect. Theanine and -aminobutyric acid can lower the blood pressure and regulate brain function. Vitamin C exhibits antiscorbutic activity, prevents cataracts, and may boost the immune system. Majority of the scientific evidence based on cellular and animal experiments as well as a number of human epidemiological and intervention studies indicate that green tea and (--epigallocatechin gallate have beneficial health effects against various diseases. However, conflicting results have also been reported. Since confounding factors could affect the results, future studies should be designed to eliminate such factors for better understanding of the benefits of green tea on human health. Genetic and environmental factors

  12. Inhibition of MMP-9 by green tea catechins and prediction of their interaction by molecular docking analysis.

    Science.gov (United States)

    Sarkar, Jaganmay; Nandy, Suman Kumar; Chowdhury, Animesh; Chakraborti, Tapati; Chakraborti, Sajal

    2016-12-01

    Green tea polyphenolic catechins have been shown to prevent various types of diseases such as pulmonary hypertension (PAH), cancer and cardiac and neurological disorders. Matrix metalloproteinases (MMPs) play an important role in the development of PAH. The present study demonstrated that among the four green tea catechins (EGCG, ECG, EC and EGC), EGCG and ECG inhibit pro-/active MMP-9 activities in pulmonary artery smooth muscle cell culture supernatant. Based on the above, we investigated the interactions of pro-/active MMP-9 with the green tea catechins by computational methods. In silico molecular docking analysis revealed a strong interaction between pro-/active MMP-9 and EGCG/ECG, and galloyl group appears to be responsible for this enhanced interaction. The molecular docking studies corroborate our experimental observation that EGCG and ECG are mainly active in preventing both the proMMP-9 and MMP-9 activities.

  13. Effect of catechins on fattening performance, meat quality, some antioxidant and blood parameters and fattening costs in Japanese quail (Coturnix coturnix japonica).

    Science.gov (United States)

    Kara, K; Şentürk, M; Guclu, B K; Sariözkan, S; Eren, M

    2016-08-01

    The aim of this study was to investigate the effect of dietary supplementation of green tea (Camellia sinensis) catechins in quail (Coturnix coturnix japonica). Quail were fed with a basal diet, and the treatment groups were fed on the basal diet with 1.25 or 2.50 g/kg catechin supplementation for 30 d. Fattening performance and meat quality of the quail were estimated. Serum total antioxidant status (TAS), plasma and liver malondialdehyde (MDA) and some serum biochemical parameters were measured. The results showed that catechin supplementation did not affect live weight, feed intake, feed conversion ratio, carcass weight, carcass dressing or the nutrient composition of breast and thigh meats. The water holding capacity (WHC) of breast meat was increased in the 2.50 g/kg catechin treatment. Catechin supplementation increased the serum TAS, but decreased plasma MDA and liver MDA concentration as well as serum glucose and total cholesterol levels. Serum triglyceride and total protein levels were not affected by catechin supplementation. In conclusion, catechins have effective antioxidant hypoglycaemic and hypocholesterolaemic properties, as well as having the potential to increase meat quality in fattening quail. On the other hand, catechin supplementation did not have any negative effect on the fattening performance, meat nutrient composition and fattening costs in fattening quail.

  14. Study on antioxidant activity of total flavonoids in nicandra physaloides extract%复合酶酶解假酸浆黄酮苷抗氧化性研究

    Institute of Scientific and Technical Information of China (English)

    孙维蔓; 王遂

    2013-01-01

    本文研究了复合酶酶解前后假酸浆提取物的抗氧化活性能力,并采用薄层色谱法( TLC)对酶解产物中总黄酮进行了分离,利用高效液相色谱-质谱联用技术对其鉴定分析。通过对DPPH自由基、羟自由基及超氧阴离子自由基清除能力实验,酶解液抗氧化性能显著高于假酸浆提取液;酶解液的薄层及HPLC-MS法初步鉴定出假酸浆中含有桑色素、二氢槲皮素和儿茶素三种黄酮。%The enzymatic hydrolyzing condition was studied for flavonoids from Nicandra Physaloides .Flavonoid composition analysis was achieved by using TLC and HPLC-MS.According to experiment on free radical scavenging activity ,that antioxidativity of sam-ples incrdased in different degree after enzyme action.TLC and HPLC-MS shows four kinds of flavonoid aglycone:Morin、Taxifolin and Catechin.

  15. Construction of a SSR-based genetic map and identification of QTLs for catechins content in tea plant (Camellia sinensis).

    Science.gov (United States)

    Ma, Jian-Qiang; Yao, Ming-Zhe; Ma, Chun-Lei; Wang, Xin-Chao; Jin, Ji-Qiang; Wang, Xue-Min; Chen, Liang

    2014-01-01

    Catechins are the most important bioactive compounds in tea, and have been demonstrated to possess a wide variety of pharmacological activities. To characterize quantitative trait loci (QTLs) for catechins content in the tender shoots of tea plant, we constructed a moderately saturated genetic map using 406 simple sequence repeat (SSR) markers, based on a pseudo-testcross population of 183 individuals derived from an intraspecific cross of two Camellia sinensis varieties with diverse catechins composition. The map consisted of fifteen linkage groups (LGs), corresponding to the haploid chromosome number of tea plant (2n = 2x = 30). The total map length was 1,143.5 cM, with an average locus spacing of 2.9 cM. A total of 25 QTLs associated with catechins content were identified over two measurement years. Of these, nine stable QTLs were validated across years, and clustered into four main chromosome regions on LG03, LG11, LG12 and LG15. The population variability explained by each QTL was predominantly at moderate-to-high levels and ranged from 2.4% to 71.0%, with an average of 17.7%. The total number of QTL for each trait varied from four to eight, while the total population variability explained by all QTLs for a trait ranged between 38.4% and 79.7%. This is the first report on the identification of QTL for catechins content in tea plant. The results of this study provide a foundation for further cloning and functional characterization of catechin QTLs for utilization in improvement of tea plant.

  16. Construction of a SSR-based genetic map and identification of QTLs for catechins content in tea plant (Camellia sinensis.

    Directory of Open Access Journals (Sweden)

    Jian-Qiang Ma

    Full Text Available Catechins are the most important bioactive compounds in tea, and have been demonstrated to possess a wide variety of pharmacological activities. To characterize quantitative trait loci (QTLs for catechins content in the tender shoots of tea plant, we constructed a moderately saturated genetic map using 406 simple sequence repeat (SSR markers, based on a pseudo-testcross population of 183 individuals derived from an intraspecific cross of two Camellia sinensis varieties with diverse catechins composition. The map consisted of fifteen linkage groups (LGs, corresponding to the haploid chromosome number of tea plant (2n = 2x = 30. The total map length was 1,143.5 cM, with an average locus spacing of 2.9 cM. A total of 25 QTLs associated with catechins content were identified over two measurement years. Of these, nine stable QTLs were validated across years, and clustered into four main chromosome regions on LG03, LG11, LG12 and LG15. The population variability explained by each QTL was predominantly at moderate-to-high levels and ranged from 2.4% to 71.0%, with an average of 17.7%. The total number of QTL for each trait varied from four to eight, while the total population variability explained by all QTLs for a trait ranged between 38.4% and 79.7%. This is the first report on the identification of QTL for catechins content in tea plant. The results of this study provide a foundation for further cloning and functional characterization of catechin QTLs for utilization in improvement of tea plant.

  17. Effect of moderate intakes of different tea catechins and caffeine on acute measures of energy metabolism under sedentary conditions.

    Science.gov (United States)

    Gregersen, Nikolaj T; Bitz, Christian; Krog-Mikkelsen, Inger; Hels, Ole; Kovacs, Eva M R; Rycroft, Jane A; Frandsen, Erik; Mela, David J; Astrup, Arne

    2009-10-01

    Green tea may stimulate energy metabolism; however, it is unclear if acute effects are caused by specific catechins, caffeine or their combination. The objective of the present study was to examine the separate and combined effects of different catechins and caffeine on energy expenditure (EE) and fat oxidation over a single day. Fifteen healthy, normal-weight males received capsules containing placebo, caffeine alone (150 mg), or caffeine plus a catechin mixture (600 mg) enriched in either epigallocatechin-3-gallate (EGCG), epigallocatechin or a mix of catechins, in a randomised cross-over double-blinded design. On each test day EE, respiratory quotient (RQ) and substrate oxidation were measured under sedentary conditions in a respiratory chamber for 13.5 h. We found no significant treatment effect on EE (P = 0.20) or RQ (P = 0.68). EGCG with caffeine insignificantly raised EE and fat oxidation v. caffeine-only and placebo (EE 5.71 (SE 0.12) v. 5.68 (SE 0.14) v. 5.59 (SE 0.13) MJ/12.5 h, respectively; fat oxidation 84.8 (SE 5.2) v. 80.7 (SE 4.7) v. 76.8 (SE 4.0) g/12.5 h). Catechin/caffeine combinations at these dosages and mode of application had non-significant acute effects on EE and fat oxidation. The maximum observed effect on EE of about 2 % could still be meaningful for energy balance over much longer period of exposure. However, higher short-term effects reported in the literature may reflect variations in green tea extracts, added caffeine, or synergies with physical activity. The specific mechanisms and conditions that may underpin observed longer-term benefits of catechin-enriched green tea consumption on body composition remain to be confirmed.

  18. Study of flavonoids of Sechium edule (Jacq) Swartz (Cucurbitaceae) different edible organs by liquid chromatography photodiode array mass spectrometry.

    Science.gov (United States)

    Siciliano, Tiziana; De Tommasi, Nunziatina; Morelli, Ivano; Braca, Alessandra

    2004-10-20

    A liquid chromatography-mass spectrometry (LC-MS)-based method was developed for the characterization of flavonoids from Sechium edule (Jacq) Swartz (Cucurbitaceae) edible organs, a plant cultivated since pre-Colombian times in Mexico where the fruit is called chayote. Chayote is used for human consumption in many countries; in addition to the fruits, stems, leaves and the tuberous part of the roots are also eaten. Eight flavonoids, including three C-glycosyl and five O-glycosyl flavones, were detected, characterized by nuclear magnetic resonance spectroscopic data, and quantified in roots, leaves, stems, and fruits of the plant by LC-photodiode array-MS. The aglycone moieties are represented by apigenin and luteolin, while the sugar units are glucose, apiose, and rhamnose. The results indicated that the highest total amount of flavonoids was in the leaves (35.0 mg/10 g of dried part), followed by roots (30.5 mg/10 g), and finally by stems (19.3 mg/10 g).

  19. Free radical scavenging abilities of flavonoids as mechanism of protection against mutagenicity induced by tert-butyl hydroperoxide or cumene hydroperoxide in Salmonella typhimurium TA102.

    Science.gov (United States)

    Edenharder, R; Grünhage, D

    2003-09-09

    Mutagenicity induced by tert-butyl hydroperoxide (BHP) or cumene hydroperoxide (CHP) in Salmonella typhimurium TA102 was effectively reduced by flavonols with 3',4'-hydroxyl groups such as fisetin, quercetin, rutin, isoquercitrin, hyperoxide, myricetin, myricitrin, robinetin, and to a lesser extent also by morin and kaempferol (ID50=0.25-1.05 micromol per plate). With the exception of isorhamnetin, rhamnetin, morin, and kaempferol, closely similar results were obtained with both peroxides. Hydrogenation of the double bond between carbons 2 and 3 (dihydroquercetin, dihydrorobinetin) as well as the additional elimination of the carbonyl function at carbon 4 (catechins) resulted in a loss of antimutagenicity with the notable exception of catechin itself. Again, all flavones and flavanones tested were inactive except luteolin, luteolin-7-glucoside, diosmetin, and naringenin. The typical radical scavenger butylated hydroxytoluene also showed strong antimutagenicity against CHP (ID50=5.4 micromol per plate) and BHP (ID50=11.4 micromol per plate). Other lipophilic scavengers such as alpha-tocopherol and N,N'-diphenyl-1,4-phenylenediamine exerted only moderate effects, the hydrophilic scavenger trolox was inactive. The metal chelating agent 1,10-phenanthroline strongly reduced mutagenicities induced by CHP and BHP (ID50=2.75 and 2.5 micromol per plate) at low concentrations but induced mutagenic activities at higher concentrations. The iron chelator deferoxamine mesylate, however, was less effective in both respects. The copper chelator neocuproine effectively inhibited mutagenicity induced by BHP (ID50=39.7 micromol per plate) and CHP (ID50=25.9 micrommol per plate), the iron chelator 2,2'-dipyridyl was less potent (ID50=6.25 mmol per plate against BHP, 0.42 mmol per plate against CHP). In the absence of BHP and CHP, yet not in the presence of these hydroperoxides, quercetin, rutin, catechin, epicatechin, and naringenin induced strong mutagenic activities in S

  20. Dietary supplementation with mulberry leaf flavonoids inhibits methanogenesis in sheep.

    Science.gov (United States)

    Ma, Tao; Chen, Dan-Dan; Tu, Yan; Zhang, Nai-Feng; Si, Bing-Wen; Diao, Qi-Yu

    2017-01-01

    The effects of flavonoids on methanogenesis and microbial flora in Dorper × thin-tailed Han crossbred ewes were evaluated in two experiments. To investigate the effects of flavonoids on nutrient digestibility and nitrogen balance, 18 ewes (60.0 ± 1.73 kg body weight (BW)) were allotted to two dietary treatments in experiment one, a control diet and the control diet supplemented with flavonoids (2 g/head/day). In experiment two, the effects of supplementary flavonoids on ruminal fermentation and microbial flora were investigated using quantitative polymerase chain reaction with six ewes (67.2 ± 0.79 kg BW) with ruminal cannula assigned to the identical dietary treatments used in experiment one. Supplementary flavonoids improved the apparent digestibility of nitrogen (N, P flavonoids, whereas the total volatile fatty acid (VFA) content increased (P = 0.037). Supplementary flavonoids decreased ruminal populations of protozoans (P = 0.002) and methanogens (P flavonoids improved the digestibility of organic matter and reduced CH4 output by inhibiting the populations of microbes involved in methanogenesis.