WorldWideScience

Sample records for vvmybf1 regulates flavonol

  1. Ultraviolet-B radiation and water deficit interact to alter flavonol and anthocyanin profiles in grapevine berries through transcriptomic regulation.

    Science.gov (United States)

    Martínez-Lüscher, Johann; Sánchez-Díaz, Manuel; Delrot, Serge; Aguirreolea, Jone; Pascual, Inmaculada; Gomès, Eric

    2014-11-01

    UV-B radiation and water deficit may trigger flavonol and anthocyanin biosynthesis in plant tissues. In addition, previous research has showed strong qualitative effects on grape berry skin flavonol and anthocyanin profiles in response to UV-B and water deficit. The aim of this study is to identify the mechanisms leading to quantitative and qualitative changes in flavonol and anthocyanin profiles, in response to separate and combined UV-B and water deficit. Grapevines (Vitis vinifera L. cv. Tempranillo) were exposed to three levels of UV-B radiation (0, 5.98 and 9.66 kJ m(-2) day(-1)) and subjected to two water regimes. A strong effect of UV-B on flavonol and anthocyanin biosynthesis was found, resulting in an increased anthocyanin concentration and a change in their profile. Concomitantly, two key biosynthetic genes (FLS1 and UFGT) were up-regulated by UV-B, leading to increased flavonol and anthocyanin skin concentration. Changes in flavonol and anthocyanin composition were explained to a large extend by transcript levels of F3'H, F3'5'H and OMT2. A significant interaction between UV-B and water deficit was found in the relative abundance of 3'4' and 3'4'5' substituted flavonols, but not in their anthocyanin homologues. The ratio between 3'4'5' and 3'4' substituted flavonols was linearly related to the ratios of F3'5'H and FLS1 transcription, two steps up-regulated independently by water deficit and UV-B radiation, respectively. Our results indicate that changes in flavonol profiles in response to environmental conditions are not only a consequence of changes in the expression of flavonoid hydroxylases; but also the result of the competition of FLS, F3'5'H and F3'H enzymes for the same flavonol substrates.

  2. A R2R3-MYB transcription factor regulates the flavonol biosynthetic pathway in a traditional Chinese medicinal plant, Epimedium sagittatum

    Directory of Open Access Journals (Sweden)

    Wenjun Huang

    2016-07-01

    Full Text Available Flavonols as plant secondary metabolites with vital roles in plant development and defense against UV light, have been demonstrated to be the main bioactive components in the genus Epimedium plants, several species of which are used as materials for Herba Epimedii, an important traditional Chinese medicine. The flavonol biosynthetic pathway genes had been already isolated from E. sagittatum, but a R2R3-MYB transcription factor regulating the flavonol synthesis has not been functionally characterized so far in Epimedium plants. In this study, we isolated and characterized the R2R3-MYB transcription factor EsMYBF1 involved in regulation of the flavonol biosynthetic pathway from E. sagittatum. Sequence analysis indicated that EsMYBF1 belongs to the subgroup 7 of R2R3-MYB family which contains the flavonol-specific MYB regulators identified to date. Transient reporter assay showed that EsMYBF1 strongly activated the promoters of EsF3H (flavanone 3-hydroxylase and EsFLS (flavonol synthase, but not the promoters of EsDFRs (dihydroflavonol 4-reductase and EsANS (anthocyanidin synthase in transiently transformed Nicotiana benthamiana leaves. Both yeast two-hybrid assay and transient reporter assay validated EsMYBF1 to be independent of EsTT8, or AtTT8 bHLH regulators of the flavonoid pathway as cofactors. Ectopic expression of EsMYBF1 in transgenic tobacco resulted in the increased flavonol content and the decreased anthocyanin content in flowers. Correspondingly, the structural genes involved in flavonol synthesis were upregulated in the EsMYBF1 overexpression lines, including NtCHS (chalcone synthase, NtCHI (chalcone isomerase, NtF3H and NtFLS, whereas the late biosynthetic genes of the anthocyanin pathway (NtDFR and NtANS were remarkably downregulated, compared to the controls. These results suggest that EsMYBF1 is a flavonol-specific R2R3-MYB regulator, and involved in regulation of the biosynthesis of the flavonol-derived bioactive components in E

  3. Involvement of P-glycoprotein in regulating cellular levels of Ginkgo flavonols: quercetin, kaempferol, and isorhamnetin.

    Science.gov (United States)

    Wang, Yi; Cao, Jiang; Zeng, Su

    2005-06-01

    Quercetin, kaempferol, and isorhamnetin were the most important flavonoid constituents in extracts from Ginkgo biloba leaves. Transport studies of Ginkgo flavonols were performed in Caco-2 cell mono-layers. Their apparent permeability in absorptive and secretion directions was determined, and quercetin, kaempferol and isorhamnetin displayed polarized transport, with the Papp,B-A being higher than the Papp,A-B (Pisorhamnetin, Student's t-test). Bcap37/MDR1 cells, which were transfected with a P-glycoprotein (P-gp) gene construct, were treated with quercetin, kaempferol or isorhamnetin. The concentrations of Ginkgo flavonol in Bcap37/MDR1 cells were lower than those in parent cells (Pisorhamnetin, Mann-Whitney U test). The concentrations of the flavonol in transfected cells increased when incubated with the P-gp inhibitor verapamil (Pisorhamnetin stimulated the ATPase activity (Pisorhamnetin, Mann Whitney U test). The results indicated that Ginkgo flavonols quercetin, kaempferol and isorhamnetin were substrates of P-gp. The P-gp type efflux pump might limit the bioavailability of Ginkgo flavonols.

  4. Post-veraison sunlight exposure induces MYB-mediated transcriptional regulation of anthocyanin and flavonol synthesis in berry skins of Vitis vinifera

    Science.gov (United States)

    Matus, José Tomás; Loyola, Rodrigo; Vega, Andrea; Peña-Neira, Alvaro; Bordeu, Edmundo; Arce-Johnson, Patricio; Alcalde, José Antonio

    2009-01-01

    Anthocyanins, flavan-3-ols, and flavonols are the three major classes of flavonoid compounds found in grape berry tissues. Several viticultural practices increase flavonoid content in the fruit, but the underlying genetic mechanisms responsible for these changes have not been completely deciphered. The impact of post-veraison sunlight exposure on anthocyanin and flavonol accumulation in grape berry skin and its relation to the expression of different transcriptional regulators known to be involved in flavonoid synthesis was studied. Treatments consisting of removing or moving aside the basal leaves which shade berry clusters were applied. Shading did not affect sugar accumulation or gene expression of HEXOSE TRANSPORTER 1, although in the leaf removal treatment, these events were retarded during the first weeks of ripening. Flavonols were the most drastically reduced flavonoids following shading and leaf removal treatments, related to the reduced expression of FLAVONOL SYNTHASE 4 and its putative transcriptional regulator MYB12. Anthocyanin accumulation and the expression of CHS2, LDOX, OMT, UFGT, MYBA1, and MYB5a genes were also affected. Other regulatory genes were less affected or not affected at all by these treatments. Non-transcriptional control mechanisms for flavonoid synthesis are also suggested, especially during the initial stages of ripening. Although berries from the leaf removal treatment received more light than shaded fruits, malvidin-3-glucoside and total flavonol content was reduced compared with the treatment without leaf removal. This work reveals that flavonol-related gene expression responds rapidly to field changes in light levels, as shown by the treatment in which shaded fruits were exposed to light in the late stages of ripening. Taken together, this study establishes MYB-specific responsiveness for the effect of sun exposure and sugar transport on flavonoid synthesis. PMID:19129169

  5. Characterization of a citrus R2R3-MYB transcription factor that regulates the flavonol and hydroxycinnamic acid biosynthesis

    Science.gov (United States)

    Flavonols and hydroxycinnamic acids are important phenylpropanoid metabolites in plants. In this study, we isolated and characterized a citrus R2R3-MYB transcription factor CsMYBF1, encoding a protein belonging to the flavonol-specific MYB subgroup. Ectopic expression of CsMYBF1 in tomato led to an ...

  6. Auxin and ethylene induce flavonol accumulation through distinct transcriptional networks.

    Science.gov (United States)

    Lewis, Daniel R; Ramirez, Melissa V; Miller, Nathan D; Vallabhaneni, Prashanthi; Ray, W Keith; Helm, Richard F; Winkel, Brenda S J; Muday, Gloria K

    2011-05-01

    Auxin and ethylene are key regulators of plant growth and development, and thus the transcriptional networks that mediate responses to these hormones have been the subject of intense research. This study dissected the hormonal cross talk regulating the synthesis of flavonols and examined their impact on root growth and development. We analyzed the effects of auxin and an ethylene precursor on roots of wild-type and hormone-insensitive Arabidopsis (Arabidopsis thaliana) mutants at the transcript, protein, and metabolite levels at high spatial and temporal resolution. Indole-3-acetic acid (IAA) and 1-aminocyclopropane-1-carboxylic acid (ACC) differentially increased flavonol pathway transcripts and flavonol accumulation, altering the relative abundance of quercetin and kaempferol. The IAA, but not ACC, response is lost in the transport inhibitor response1 (tir1) auxin receptor mutant, while ACC responses, but not IAA responses, are lost in ethylene insensitive2 (ein2) and ethylene resistant1 (etr1) ethylene signaling mutants. A kinetic analysis identified increases in transcripts encoding the transcriptional regulators MYB12, Transparent Testa Glabra1, and Production of Anthocyanin Pigment after hormone treatments, which preceded increases in transcripts encoding flavonoid biosynthetic enzymes. In addition, myb12 mutants were insensitive to the effects of auxin and ethylene on flavonol metabolism. The equivalent phenotypes for transparent testa4 (tt4), which makes no flavonols, and tt7, which makes kaempferol but not quercetin, showed that quercetin derivatives are the inhibitors of basipetal root auxin transport, gravitropism, and elongation growth. Collectively, these experiments demonstrate that auxin and ethylene regulate flavonol biosynthesis through distinct signaling networks involving TIR1 and EIN2/ETR1, respectively, both of which converge on MYB12. This study also provides new evidence that quercetin is the flavonol that modulates basipetal auxin transport.

  7. 7-Rhamnosylated Flavonols Modulate Homeostasis of the Plant Hormone Auxin and Affect Plant Development.

    Science.gov (United States)

    Kuhn, Benjamin M; Errafi, Sanae; Bucher, Rahel; Dobrev, Petre; Geisler, Markus; Bigler, Laurent; Zažímalová, Eva; Ringli, Christoph

    2016-03-04

    Flavonols are a group of secondary metabolites that affect diverse cellular processes. They are considered putative negative regulators of the transport of the phytohormone auxin, by which they influence auxin distribution and concomitantly take part in the control of plant organ development. Flavonols are accumulating in a large number of glycosidic forms. Whether these have distinct functions and diverse cellular targets is not well understood. The rol1-2 mutant of Arabidopsis thaliana is characterized by a modified flavonol glycosylation profile that is inducing changes in auxin transport and growth defects in shoot tissues. To determine whether specific flavonol glycosides are responsible for these phenotypes, a suppressor screen was performed on the rol1-2 mutant, resulting in the identification of an allelic series of UGT89C1, a gene encoding a flavonol 7-O-rhamnosyltransferase. A detailed analysis revealed that interfering with flavonol rhamnosylation increases the concentration of auxin precursors and auxin metabolites, whereas auxin transport is not affected. This finding provides an additional level of complexity to the possible ways by which flavonols influence auxin distribution and suggests that flavonol glycosides play an important role in regulating plant development.

  8. Differential stress-response expression of two flavonol synthase genes and accumulation of flavonols in tartary buckwheat.

    Science.gov (United States)

    Li, Xiaohua; Kim, Yeon Bok; Kim, Yeji; Zhao, Shicheng; Kim, Haeng Hoon; Chung, Eunsook; Lee, Jai-Heon; Park, Sang Un

    2013-12-15

    Flavonoids are ubiquitously present in plants and play important roles in these organisms as well as in the human diet. Flavonol synthase (FLS) is a key enzyme of the flavonoid biosynthetic pathway, acting at the diverging point into the flavonol subclass branch. We isolated and characterized a FLS isoform gene, FtFLS2, from tartary buckwheat (Fagopyrum tataricum). FtFLS2 shares 48% identity and 67% similarity with the previously reported FtFLS1, whereas both genes share 47-65% identity and 65-69% similarity with FLSs from other plant species. Using quantitative real-time PCR and high-performance liquid chromatography (HPLC), the expression of FtFLS1/2 and the production of 3 main flavonols (kaempferol, myricetin and quercetin) was detected in roots, leaves, stems, flowers and different stages of developing seeds. The relationship between the expression of the 2 FLS genes and the accumulation of the 3 basic flavonols was analyzed in 2 tartary buckwheat cultivars. FtFLS1 and FtFLS2 exhibited differential transcriptional levels between the tartary buckwheat cultivars 'Hokkai T10' and 'Hokkai T8'. Generally, higher transcript levels of FtFLS1 and FtFLS2 and a higher amount of flavonols were observed in the 'Hokkai T10' cultivar than 'Hokkai T8'. The content of flavonols showed tissue-specific accumulation between the 2 cultivars. The transcription of FtFLS1 was inhibited by the exogenous application of abscisic acid (ABA), salicylic acid (SA) and sodium chloride (NaCl), while FtFLS2 was not affected by ABA but up-regulated by SA and NaCl. These data indicate that the 2 FtFLS isoforms of buckwheat have different functions in the response of buckwheat to environmental stress.

  9. Acetylated flavonol triglycosides from Ammi majus L.

    Science.gov (United States)

    Singab, A N

    1998-12-01

    Two new acetylated flavonol triglycosides: kaempferol and isorhamnetin 3-O-[2"-(4"'-acetylrhamnosyl)-6"-glucosyl] glucosides, were isolated and identified from the aerial parts of Ammi majus L. In addition, three known flavonol glycosides namely; isorhamnetin-3-O-rutinoside, kaempferol-3-O-glucoside and isorhamnetin-3-O-glucoside were detected.

  10. Neuroprotective actions of flavones and flavonols: mechanisms and relationship to flavonoid structural features.

    Science.gov (United States)

    Dajas, Federico; Andrés, Abin-Carriquiry Juan; Florencia, Arredondo; Carolina, Echeverry; Felicia, Rivera-Megret

    2013-03-01

    Epidemiological studies have shown positive preventive action of flavonoids on cardiovascular and neurodegenerative events. Among the six groups in which flavonoids are classified, the flavones and flavonols, based on the backbone of 2-phenylchromen-4-one (2-phenyl-1-benzopyran-4-one) are the most commonly encountered within the families and genera of the higher plants. Numerous studies support a neuroprotective activity of flavones such as luteolin and flavonols such as kaempherol and quercetin in experimental focal ischemia and models of neurodegeneration. Antioxidation, modulation of signaling cascades and gene expression as well as anti-inflammation appear as the main protective mechanisms and mitochondria are a likely main target mediating the preventive actions against oxidative stress. Flavones and flavonols re-establish the redox regulation of proteins, transcription factors and signaling cascades that are otherwise inhibited by elevated oxidative stress. The final survival or death of the neuron depends on flavone and flavonol concentrations, time of exposure and, mainly, metabolic and oxidative neuronal circumstances. Neuroprotection appears to be linked to specific structural motifs, beyond those involved in antioxidation. By themselves or as templates for synthetic compounds, flavone and flavonol molecules show potential as multi-targeted therapeutic tools for protecting the brain. Nonetheless, more research needs to be done on the correlation of potential beneficial effects of flavones and flavonols and their mechanisms of action.

  11. Dietary Flavonols and Flavonol-rich foods intake and the risk of breast cancer

    NARCIS (Netherlands)

    Adebamowo, C.A.; Sampson, L.; Katan, M.B.; Spiegelman, D.; Willett, W.C.; Holmes, M.D.; Cho, E.

    2005-01-01

    Laboratory and animal studies suggest that dietary flavonols may reduce breast cancer risk but there are limited epidemiological studies. We computed flavonol intakes from dietary data collected by validated food frequency questionnaires in 1991 and 1995 from 90,630 women in the Nurses Health Study

  12. Anthocyanins and flavonols are responsible for purple color of Lablab purpureus (L.) sweet pods.

    Science.gov (United States)

    Cui, Baolu; Hu, Zongli; Zhang, Yanjie; Hu, Jingtao; Yin, Wencheng; Feng, Ye; Xie, Qiaoli; Chen, Guoping

    2016-06-01

    Lablab pods, as dietary vegetable, have high nutritional values similar to most of edible legumes. Moreover, our studies confirmed that purple lablab pods contain the natural pigments of anthocyanins and flavonols. Compared to green pods, five kinds of anthocyanins (malvidin, delphinidin and petunidin derivatives) were found in purple pods by HPLC-ESI-MS/MS and the major contents were delphinidin derivatives. Besides, nine kinds of polyphenol derivatives (quercetin, myricetin, kaempferol and apigenin derivatives) were detected by UPLC-ESI-MS/MS and the major components were quercetin and myricetin derivatives. In order to discover their molecular mechanism, expression patterns of biosynthesis and regulatory gens of anthocyanins and flavonols were investigated. Experimental results showed that LpPAL, LpF3H, LpF3'H, LpDFR, LpANS and LpPAP1 expressions were significantly induced in purple pods compared to green ones. Meanwhile, transcripts of LpFLS were more abundant in purple pods than green or yellow ones, suggestind that co-pigments of anthocyanins and flavonols are accumulated in purple pods. Under continuously dark condition, no anthocyanin accumulation was detected in purple pods and transcripts of LpCHS, LpANS, LpFLS and LpPAP1 were remarkably repressed, indicating that anthocyanins and flavonols biosynthesis in purple pods was regulated in light-dependent manner. These results indicate that co-pigments of anthocyanins and flavonols contribute to purple pigmentations of pods.

  13. New Acetylated Flavonol Glycosides from Knoxia corymbosa

    Institute of Scientific and Technical Information of China (English)

    Yu Bo WANG; Jian Xin PU; Hai Ying, REN; Jing Feng ZHAO; Shuang Xi MEI; Zi Yan LI; Hong Bin ZHANG; Liang LI

    2003-01-01

    Two new diacetylated flavonol glycosides, kampferol-3-O-β-3〃, 6〃-diacetylglucopyrano- side and quercetin-3-O-β-3〃, 6〃-diacetylglucopyranoside were isolated from knoxia corymbosa. Their structures were elucidated by spectroscopic evidents.

  14. Functional analyses of a flavonol synthase - like gene from Camellia nitidissima reveal its roles in flavonoid metabolism during floral pigmentation

    Indian Academy of Sciences (India)

    Xing-Wen Zhou; Zheng-Qi Fan; Yue Chen; Yu-Lin Zhu; Ji-Yuan Li; Heng-Fu Yin

    2013-09-01

    The flavonoids metabolic pathway plays central roles in floral coloration, in which anthocyanins and flavonols are derived from common precursors, dihydroflavonols. Flavonol synthase (FLS) catalyses dihydroflavonols into flavonols, which presents a key branch of anthocyanins biosynthesis. The yellow flower of Camellia nitidissima Chi. is a unique feature within the genus Camellia, which makes it a precious resource for breeding yellow camellia varieties. In this work, we characterized the secondary metabolites of pigments during floral development of C. nitidissima and revealed that accumulation of flavonols correlates with floral coloration. We first isolated CnFLS1 and showed that it is a FLS of C. nitidissima by gene family analysis. Second, expression analysis during floral development and different floral organs indicated that the expression level of CnFLS1 was regulated by developmental cues, which was in agreement with the accumulating pattern of flavonols. Furthermore, over-expression of CnFLS1 in Nicotiana tabacum altered floral colour into white or light yellow, and metabolic analysis showed significant increasing of flavonols and reducing of anthocyanins in transgenic plants. Our work suggested CnFLS1 plays critical roles in yellow colour pigmentation and is potentially a key point of genetic engineering toward colour modification in Camellia.

  15. Two New Flavonol Glycosides from Knoxia corymbosa

    Institute of Scientific and Technical Information of China (English)

    Yu Bo WANG; Shuang Xi MEI; Yao Hua WANG; Jing Feng ZHAO; Hai Ying REN; Jie GUO; Hong Bin ZHANG; Liang LI

    2003-01-01

    Two new flavonol glycosides (1 and 2) together with two known flavonoides (3 and 4),were isolated from the whole plant of Knoxia corymbosa willd. The structures of 1 and 2 wereelucidated as kaempferol-7-O-α-L-arabinosyl-3-O-β-D-6"-acetylglucopyranoside and kaempferol-7-O-α-L-arabinosyl-3-O-β-D-3",6"-diacetylglucopyranoside respectively.

  16. Superior anticancer activity of halogenated chalcones and flavonols over the natural flavonol quercetin.

    Science.gov (United States)

    Dias, Tatiana A; Duarte, Cecília L; Lima, Cristovao F; Proença, M Fernanda; Pereira-Wilson, Cristina

    2013-07-01

    A series of chalcone and flavonol derivatives were synthesized in good yield by an eco-friendly approach. A pharmacological evaluation was performed with the human colorectal carcinoma cell line HCT116 and revealed that the anticancer activity of flavonols was higher when compared with that of the respective chalcone precursors. The antiproliferative activity of halogenated derivatives increases as the substituent in the 3- or 4-positon of the B-ring goes from F to Cl and to Br. In addition, halogens in position 3 enhance anticancer activity in chalcones whereas for flavonol derivatives the best performance was registered for the 4-substituted derivatives. Flow cytometry analysis showed that compounds 3p and 4o induced cell cycle arrest and apoptosis as demonstrated by increased S, G2/M and sub-G1 phases. These data were corroborated by western blot and fluorescence microscopy analysis. In summary, halogenated chalcones and flavonols were successfully prepared and presented high anticancer activity as shown by their cell growth and cell cycle inhibitory potential against HCT116 cells, superior to that of quercetin, used as a positive control.

  17. New iodine derivatives of flavonol and isoflavone

    Directory of Open Access Journals (Sweden)

    Mário G. de Carvalho

    2009-03-01

    Full Text Available The reaction of the flavonol 3,7,3', 4'-tetra-O-methylquercetin (1 and of the isoflavone 7,4'-di-O-methylgenistein (2 with alkaline iodine in methanol afforded four new iodine derivatives: 8-iodo-5-hydroxy-3,7,3', 4'-tetramethoxy- flavone (1a and 6-iodo-5-hydroxy-3,7,3', 4'-tetramethoxyflavone (1b from 1; 2 afforded a mixture of two compounds, identified as a racemic mixture of (±-trans-5-hydroxy-2,3,7,4'-tetramethoxy-8-iodo-isoflavanone (2a and (±-trans-5-hydroxy-2,3,7,4'-tetramethoxy-6,8-diiodo-isoflavanone (2b. The formation of these different products reveals a significant difference involving the chemical interaction between the reactive site of α, β-unsaturated ketones of flavonol and isoflavone under the tested reaction conditions (using I2/KOH/MeOH. Furthermore, the trans stereo selectivity is noteworthy in the nucleophylic addition of methanol at the isoflavone α, β-unsaturated system. The structures were identified on the basis of spectral data, mainly 1D and 2D NMR and mass spectra.A reação do flavonol 3,7,3',4'-tetra-O-metilquercetina (1 e da isoflavona 7,4'-di-O-metilgenisteina (2 com iodo/KOH em metanol forneceu como produto quatro derivados iodados: 8-iodo-5-hidroxi-3,7,3',4'-tetrametoxiflavona (1a e 6-iodo-5-hidroxi-3,7,3',4'-tetrametoxiflavona (1b a partir da iodação de 1; a partir de 2 foi obtida uma mistura racêmica composta de (±-trans-5-hidroxi-2,3,7,4'-tetrametoxi-8-iodo-isoflavanona (2a e (±-trans-5-hidroxi-2,3,7,4'-tetrametoxi-6,8-diiodo-isoflavanona (2b. A formação destes diferentes produtos revela a significante diferença envolvendo a interação química entre o sitio reativo de cetonas α, β-insaturadas de flavonol e de isoflavonas nas condições experimentais testadas (usando I2/KOH/MeOH. Além disso, ressalta-se a estereosseletividade trans na adição de metanol ao sistema α, β-insaturado da isoflavona. As estruturas foram identificadas com análise nos dados espectrométricos de RMN 1D e 2D e

  18. Fluorescence imaging of soybean flavonol isolines

    Science.gov (United States)

    Kim, Moon S.; Lee, Edward H.; Mulchi, Charles L.; McMurtrey, James E., III; Chappelle, Emmett W.; Rowland, Randy A.

    1998-07-01

    Experiments were conducted to characterize the fluorescence emission of leaves from four soybean ('Harosoy') plants containing different concentrations of flavonols (kaempferol glycosides). The investigation utilized genetically mutated soybean flavonol isolines grown in a constant environment, thus limiting factors known to affect fluorescence emission characteristics other than different kaempferol glycosides concentrations. Flavonol isolines included OX922, OX941, OX942, OX944. The first two isolines contain kaempferol (K) glycosides; K3, K6, and K9, and the latter two did not have K3, K6, and K9. A fluorescence imaging system (FIS) was used to characterize steady state florescence images of the sample leaves measured at wavelengths centered at 450, 550, 680, and 740 nm with an excitation at 360 nm. Images taken with FIS greatly complement non-imaging fluorescence measurements by characterizing the spatial variation of fluorescence within leaves. We also acquired fluorescence emission spectra to characterize spectral features of the soybean flavonol isolines. The emission spectral shape of the fluorescence emission characteristics were not significantly different between the soybeans that contain kaempferol glycosides and the ones that do not contain kaempferol glycosides. Typical emission maxima of green vegetation in the blue, green, red, and far-red bands were noticed in all four soybean isolines. However, plants containing kaempferol glycosides, OX922 and OX941 had significantly lower intensities throughout the wavelength regions. These results imply that fluorescence emission intensities in the fluorescence emission bands studied are significantly affected by the presence and absence of kaempferol glycosides concentrations (UV radiation screening compounds). Pure kaempferol glycoside dissolved in solution show minimal fluorescence emission when excited with the absorption maximum radiation at 365 nm. However, a broad band emission can be seen in the green

  19. Post-transcriptional silencing of flavonol synthase mRNA in tobacco leads to fruits with arrested seed set.

    Directory of Open Access Journals (Sweden)

    Monika Mahajan

    Full Text Available Flavonoids are synthesized by phenylpropanoid pathway. They are known to participate in large number of physiological and biochemical processes in plants. Parthenocarpy and male sterility has earlier been reported by silencing chalcone synthase (CHS encoding gene. Silencing of CHS has blocked the synthesis of most of useful flavonoids including flavan-3-ols and flavonols. Also, these studies could not identify whether parthenocarpy/male sterility were due to lack of flavan-3-ols or flavonols or both. Flavonol synthase (FLS is an important enzyme of flavonoid pathway that catalyzes the formation of flavonols. In this article, we propose a novel strategy towards the generation of seedless or less-seeded fruits by downregulation of flavonol biosynthesis in tobacco (Nicotiana tabacum cv Xanthi through post-transcriptional gene silencing (PTGS of FLS encoding mRNA. The FLS silenced lines were observed for 20-80% reduction in FLS encoding gene expression and 25-93% reduction in flavonol (quercetin content. Interestingly, these FLS silenced tobacco lines also showed reduction in their anthocyanidins content. While the content of flavan-3-ols (catechin, epi-catechin and epi-gallocatechin was found to be increased in FLS silenced lines. The delayed flowering in FLS silenced lines could be due to decrease in level of indole acetic acid (IAA at apical region of their shoots. Furthermore, the pollen germination was hampered and pollens were unable to produce functional pollen tube in FLS silenced tobacco lines. Pods of FLS silenced lines contained significantly less number of seeds. The in vitro and in vivo studies where 1 µM quercetin was supplied to germination media, documented the restoration of normal pollen germination and pollen tube growth. This finding identified the role of flavonols particularly quercetin in pollen germination as well as in the regulation of plant fertility. Results also suggest a novel approach towards generation of seedless

  20. [Physico-chemical characterisation of Zn-flavonols complexes].

    Science.gov (United States)

    Muntean, Daniela; Imre, Silvia; Vari, C E

    2007-01-01

    The aim of flavonols complexation is to improve their specific activity. The flavonols sources were Morus alba L. and Morus nigra L., zinc being the biological active ion. Physico-chemical characterization was made by thin-layer chromatography, UV-VIS spectrophotometry, IR spectrometry and polarography. The complexes results were within acceptability limits, but their obtaining is economically inefficient.

  1. Acylated flavonol glycosides from Tagetes minuta with antibacterial activity

    Directory of Open Access Journals (Sweden)

    Irum eShahzadi

    2015-09-01

    Full Text Available Wild marigold (Tagetes minuta, a flowering plant of the family Asteraceae contains compounds of pharmaceutical and nutritional importance especially essential oils and flavonols. Identification, characterization of flavonols and determination of their antibacterial activity were major objectives of the current study. The isolation and purification of flavonols was accomplished using chromatographic techniques while structural elucidation was completed by LC-MS and NMR spectroscopy. The extracts and purified compounds were tested against various bacterial strains for antibacterial activity. A total of nineteen flavonols were isolated from this species. Of these, seventeen were of butanol and two of ethyl acetate extracts. Based on the concentration and purity, eight potential flavonols were selected and structurally elucidated. Four flavonols, 6-hydroxyquercetin 7-O-β-(6''-galloylglucopyranoside (2, 6-hydroxykaempferol 7-O-β-glucopyranoside (5, 6-hydroxykaempferol 7-O-β-(6''-galloylglucopyranoside (7, 6-hydroxyquercetin 7-O-β-(6''-caffeoylglucopyranoside (9, were identified for the first time from T. minuta. Butanol and ethyl acetate extracts of flowers and seeds showed significant antibacterial activity against Micrococcus leteus, Staphylococcus aureus, Bacillus subtilis and Pseudomonas piket. Among the isolated flavonols only 1, 2 and 18 were found to possess significant antibacterial activity against M. luteus. The extracts and purified flavonols from T. minuta can be potential candidates for antibacterial drug discovery and support to ethnopharmacological use.

  2. Disequilibrium of flavonol synthase and dihydroflavonol-4-reductase expression associated tightly to white versus red color flower formation in plants

    Directory of Open Access Journals (Sweden)

    Ping eLuo

    2016-01-01

    Full Text Available Flower colour is the main character throughout the plant kingdom. Though substantial information exists regarding the structural and regulatory genes involved in anthocyanin and flavonol biosynthesis, little is known that what make a diverse white versus red color flower in natural species. Here, the contents of pigments in seven species from varied phylogenetic location in plants with red and white flowers.were determined. Flavonols could be detected in red and white flowers, but anthocyanins were almost undetectable in the white cultivar. Comparisons of expression patterns of gene related to the flavonoid biosynthesis indicated that disequilibrium expression of flavonol synthase (FLS and dihydroflavonol-4-reductase (DFR genes determined the accumulation of flavonols and anothcyanins in both red and white flowers of seven species. To further investigate the role of such common regulatory patterns in determining flower color, FLS genes were isolated from Rosa rugosa (RrFLS1, Prunus persica (PpFLS and Petunia hybrida (PhFLS, and DFR genes were isolated from Rosa rugosa (RrDFR1 and Petunia hybrida (PhDFR. Heterologous expression of the FLS genes within tobacco host plants demonstrated conservation of function, with the transgenes promoting flavonol biosynthesis and inhibiting anthocyanin accumulation, so resulting in white flowers. Conversely, overexpression of DFR genes in tobacco displayed down-regulation of the endogenous NtFLS gene, and the promotion of anthocyanin synthesis. On this basis, we propose a model in which FLS and DFR gene-products compete for common substrates in order to direct the biosynthesis of flavonols and anthocyanins, respectively, thereby determining white versus red coloration of flowers.

  3. Simultaneous Determination of Flavonols and Terpene Lactones in ...

    African Journals Online (AJOL)

    ... Flavonols and Terpene. Lactones in Beagle Dog Plasma by Ultra-Performance ... International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African ..... Extracts: A Review of the Pharmacokinetics of the.

  4. A New Flavonol Triglycoside and Other Flavonol Glycosides from Astragalus armatus Willd. (Fabaceae

    Directory of Open Access Journals (Sweden)

    Assia Khalfallah

    2014-01-01

    Full Text Available From the aerial parts of Astragalus armatus, a new acylated flavonol triglycoside, isorhamnetin-3-O-(5'''-p-hydroxybenzoyl-β-apiofuranosyl-(1→2[ α -rhamnopyranosyl-(1→6]- β -galactopyranoside (1 which we named astrarmatuside, has been isolated and structurally elucidated together with seven known flavonol glycosides: tamarixetin-3-O- α -apiofuranosyl-(1→2[ α -rhamnopyranosyl-(1→6]- β -galactopyranoside (2 (m illettias p ec oside D , isorhamnetin-3-O-β-apiofuranosyl-(1→2[α-rhamnopyranosyl-(1→6]-β-galacto-pyranoside (3, kaempferol-3-O-α-rhamnopyranosyl-(1→2[α-rhamnopyranosyl-(1→6]-β-glucopyranoside (4, kaempferol-3-O-α-rhamnopyranosyl-(1→2[α-rhamnopyranosyl-(1→6]-β-galactopyranoside (mauritianin (5, isorhamnetin-3-O-α-rhamnopyranosyl-(1→2[α-rhamnopyranosyl-(1→6]-β-galactopyranoside (6, kaempferol-3-O-α-rhamnopyranosyl-(1→6]-β-glucopyranoside (nikotiflorin (7 and isorhamnetin-3-O-α-rhamnopyranosyl-(1→6]-β-glucopyranoside (narcissin (8 . The structures of the isolated compounds were established by means of 2D NMR experiments, HPLC-DADMS, HR-MS and UV spectral analyses. Pivotal role in the structure elucidation and in particular in the determination of sugar sequence, played HSQC-TOCSY and ROESY experiments whereas those of the known compounds (2–8 were established by spectral comparison with those published in the literature.

  5. Flavonols and flavones in foods and their relation with cancer and coronary heart disease risk.

    NARCIS (Netherlands)

    Hertog, M.G.L.

    1994-01-01

    Flavonoids are polyphenolic antioxidants occurring ubiquitously in vegetable foods. Flavonols and flavones inhibit chemically induced tumors in rodents. The flavonol quercetin also inhibits LDL oxidation and platelet aggregation in vitro . We therefore decided to investigate the relation between fla

  6. Flavonols and flavones in foods and their relation with cancer and coronary heart disease risk

    NARCIS (Netherlands)

    Hertog, M.G.L.

    1994-01-01

    Flavonoids are polyphenolic antioxidants occurring ubiquitously in vegetable foods. Flavonols and flavones inhibit chemically induced tumors in rodents. The flavonol quercetin also inhibits LDL oxidation and platelet aggregation in vitro . We therefore decided to investigate the

  7. A new flavonol glycoside from the Abelmoschus esculentus Linn.

    OpenAIRE

    2012-01-01

    Background: Abelmoschus esculentus L. belonging to the family Malvaceae is a kind of one year herbage plant, which is one of the most important vegetables widely grown in Nigeria for its tender fruits and young leaves. It's easy to be cultivated and grows well in both tropical and temperate zones, that is, it is widely planted from Africa to Asia, South European to America. A new flavonol glycoside characterized as 5,7,3′,4′-tetrahydroxy-4′′-O-methyl flavonol -3-O-β-D- glucopyranoside (1) has...

  8. Forced Degradation of Flavonol Glycosides Extraced from Ginkgo biloba

    Institute of Scientific and Technical Information of China (English)

    JIN Ye; ZHANG Wei-yu; MENG Qing-fan; LI Dan-hui; GARG Sajay; TENG Li-rong; WEN Jing-yuan

    2013-01-01

    The degradation of flavonol glycosides extracted from Ginkgo biloba was performed under different conditions and the degraded products were determined by reversed-phase high performance liquid chromatography (RP-HPLC) method.Four stress conditions including acid(0.1 mol/L HCl),base(0.1 mol/L NaOH),temperature (70 ℃) and oxidation(0.03% H2O2,volume fraction) were used for the forced degradation studies.The pH stabilities of the flavonol glycosides were determined in phosphate buffers of varying pH values from 4.5 to 7.4.The degradation rate constants and half-life of three Ginkgo flavonol aglycones(quercetin,kaempferol and isorhamnetin) which represent Ginkgo flavonol glycosides were calculated in forced degradation and pH-stability studies of them.The resuits indicate that the three substances were more stable when incubated under acid condition and showed pH-dependent stability.The degradation was observed to follow first-order kinetics in all degradation studies.The stability results could provide important bases on development,preparation and storage of products of Ginkgo biloba extract and should be significantly considered during the further formulation development.

  9. A new flavonol glycoside from the Abelmoschus esculentus Linn.

    Directory of Open Access Journals (Sweden)

    Haibing Liao

    2012-01-01

    Full Text Available Background: Abelmoschus esculentus L. belonging to the family Malvaceae is a kind of one year herbage plant, which is one of the most important vegetables widely grown in Nigeria for its tender fruits and young leaves. It′s easy to be cultivated and grows well in both tropical and temperate zones, that is, it is widely planted from Africa to Asia, South European to America. A new flavonol glycoside characterized as 5,7,3′,4′-tetrahydroxy-4′′-O-methyl flavonol -3-O-β-D- glucopyranoside (1 has been isolated from the fruit of A. esculentus together with one known compound 5,7,3′,4′-tetrahydroxy flavonol -3-O-[β-D-glucopyranosyl-(1→6]-β-D-glucopyranoside (2. The structure of the new compound was elucidated on the basis of its spectral data, including 2-D NMR and mass (MS spectra. The antioxidant activities of the isolated compounds 1 and 2 were evaluated by 2 assays, the 1,1-diphenyl-2-picryl-hydrazyl (DPPH and ferric reducing antioxidant power (FRAP. The present work deals with the isolation, identification and antioxidant activity of the two compounds. Materials and Methods: The compounds were isolated by Diaion HP-20, Sephedex LH-20 column chromatography methods, their structures were identified by physicochemical properties and spectroscopic analysis. The antioxidant activities of the isolated compounds 1 and 2 were evaluated by two assays, e.g., DPPH and FRAP. Results: Two flavonol glycosides have been isolated from the fruit of Abelmoschus esculentus L. for the first time, and the compound 1 was a new compound, the compound 2 was isolated from the plant for the first time. Conclusion: The results show that the two flavonol glycosides have strong ability for scavenging DPPH and FRAP free radical by the experiment of antioxidant activities, so A. esculentus may be a natural antioxidants resource.

  10. Evaluation of flavonols and derivatives as human cathepsin B inhibitor.

    Science.gov (United States)

    Ramalho, Suelem D; de Sousa, Lorena R F; Burger, Marcela C M; Lima, Maria Inês S; da Silva, M Fátima das G F; Fernandes, João B; Vieira, Paulo C

    2015-01-01

    Cathepsin B (catB) is a cysteine protease involved in tumour progression and represents a potential therapeutic target in cancer. Among the 15 evaluated extracts from cerrado biome, Myrcia lingua Berg. (Myrtaceae) extract demonstrated to be a source of compounds with potential to inhibit catB. Using bioactivity-guided fractionation, we have found flavonols as inhibitors and also some other derivatives were obtained. From the evaluated compounds, myricetin (5) and quercetin (6) showed the most promising results with IC50 of 4.9 and 8.2 μM, respectively, and mode of inhibition as uncompetitive on catB. The results demonstrated polyhydroxylated flavonols as promising inhibitors of catB.

  11. Flavonols and Antioxidant Activity of Ammi visnaga L. (Apiaceae

    Directory of Open Access Journals (Sweden)

    Reguia Bencheraiet

    2011-01-01

    Full Text Available Eleven flavonols have been isolated from the aerial parts of Ammi visnaga L. from which four aglycones, four monoglycosides, two diglycosides and one triglycoside. The flavonoid aglycones were distributed into one hydroxylated, quercetin (1 and three methoxylated, namely, rhamnetin (2, isorhamnetin (3 and rhamnazin (4. Among the monoglycosides, we found three 3-O-glucosides respectively linked to rhamnetin (5, isorhamnetin (6 and rhamnazin (7 and one 7-O-glucoside of isorhamnetin (8. The two diglycosides were 3-O-rutin of quercetin (9 and isorhamnetin (10 while the single trioside was quercetin 7,3,3’-O-triglucoside (11. These flavonols are reported for the first time from A. visnaga L . Free radical DPPH scavenging potential of the butanolic extract was investigated.

  12. A New Antimicrobial Flavonol Glycoside from Alchornea davidii

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new flavonol glycoside, isorhamnetin-3-O-β-D-xyloside, was isolated from the extract of leaves and twigs of Alchornea davidii (Euphorbiaceae). Its structure was established on the basis of the spectral analysis and chemical degradation. Antimicrobial assay showed that it moderately inhibited the growth of test bacteria (Staphylococcus aureus, Bacillus subtilis and Pseudomonas fluorescens) and fungi (Candida albicans, Aspergillus niger and Trichophyton rubrum) with MICs at 50 μg/Ml.

  13. A New Flavonol Oligosaccharide from the Seeds of Aesculus chinensis

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new flavonol oligosaccharide, quercetin-3-O-[b-D-xylopyranosyl-(1?2)- a-L-rhamnopyranosyl-(1?6)]-b-D-glucopyranoside-3¢-O-b-D-glucopyranoside, named aescuflavoside was isolated from Aesculus chinensis. It¢s structure was elucidated by spectra FAB-MS, 1D NMR and 2D NMR including 1H NMR, 13C NMR, HMQC and HMBC techniques.

  14. A New Flavonol Oligosaccaride from the Seeds of Aesculus chinensis

    Institute of Scientific and Technical Information of China (English)

    FengWEI; LingYunMA; 等

    2002-01-01

    A new flavonol ologosaccharide,quercetin-3-O-[β-D-xylopyranosyl-(1→2)-α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside-3′-O-β-D-glucopyranoside, named aesculfavoside was inolated from Aesculus chinensis.It′s structure was elucidatede by spectra FAB-MS,1D NMR and 2D NMR including 1H NMR,13C NMR,HMQC and HMBC techniques.

  15. Two new flavonol glycosides from Gymnema sylvestre and Euphorbia ebracteolata.

    Science.gov (United States)

    Liu, Xin; Ye, Wencai; Yu, Biao; Zhao, Shouxun; Wu, Houming; Che, Chuntao

    2004-03-15

    Two new flavonol glycosides, namely kaempferol 3-O-beta-D-glucopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-galactopyranoside (1) and quercetin 3-O-6"-(3-hydroxyl-3-methylglutaryl)-beta-D-glucopyranoside (2), have been isolated from the aerial parts of Gymnema sylvestre and Euphorbia ebracteolata, respectively. Their structures were determined on the basis of chemical and spectroscopic methods.

  16. Flavonol and chalcone ester glycosides from Bidens andicola.

    Science.gov (United States)

    De Tommasi, N; Piacente, S; Pizza, C

    1998-08-01

    Five new flavonol 7-O-glycosides (1-5), having quercetin or quercetin 3-methyl ether as their aglycons, and sugar chains made up of three or four sugars, including beta-D-glucopyranose, alpha-L-rhamnopyranose, and beta-D-xylopyranose, have been isolated from the aerial parts of Bidens andicola, along with a new chalcone ester glycoside (6) and five known chalcone ester glycosides. The structures of 1-6 were elucidated using a combination of spectroscopic techniques.

  17. Antiviral Effect of Methylated Flavonol Isorhamnetin against Influenza

    OpenAIRE

    Ahmed Abdal Dayem; Hye Yeon Choi; Young Bong Kim; Ssang-Goo Cho

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found t...

  18. Flavonols and Antioxidant Activity of Ammi visnaga L. (Apiaceae)

    OpenAIRE

    Reguia Bencheraiet; Habiba Kherrab; Ahmed Kabouche; Zahia Kabouche; Maurice Jay

    2011-01-01

    Eleven flavonols have been isolated from the aerial parts of Ammi visnaga L. from which four aglycones, four monoglycosides, two diglycosides and one triglycoside. The flavonoid aglycones were distributed into one hydroxylated, quercetin (1) and three methoxylated, namely, rhamnetin (2), isorhamnetin (3) and rhamnazin (4). Among the monoglycosides, we found three 3-O-glucosides respectively linked to rhamnetin (5), isorhamnetin (6) and rhamnazin (7) and one 7-O-glucoside of isorhamnetin (8). ...

  19. Combinatorial biosynthesis of flavones and flavonols in Escherichia coli.

    Science.gov (United States)

    Miyahisa, Ikuo; Funa, Nobutaka; Ohnishi, Yasuo; Martens, Stefan; Moriguchi, Takaya; Horinouchi, Sueharu

    2006-06-01

    (2S)-Flavanones (naringenin and pinocembrin) are key intermediates in the flavonoid biosynthetic pathway in plants. Recombinant Escherichia coli cells containing four genes for a phenylalanine ammonia-lyase, cinnamate/coumarate:CoA ligase, chalcone synthase, and chalcone isomerase, in addition to the acetyl-CoA carboxylase, have been established for efficient production of (2S)-naringenin from tyrosine and (2S)-pinocembrin from phenylalanine. Further introduction of the flavone synthase I gene from Petroselinum crispum under the control of the T7 promoter and the synthetic ribosome-binding sequence in pACYCDuet-1 caused the E. coli cells to produce flavones: apigenin (13 mg/l) from tyrosine and chrysin (9.4 mg/l) from phenylalanine. Introduction into the E. coli cells of the flavanone 3beta-hydroxylase and flavonol synthase genes from the plant Citrus species led to production of flavonols: kaempferol (15.1 mg/l) from tyrosine and galangin (1.1 mg/l) from phenylalanine. The combinatorial biosynthesis of the flavones and flavonols in E. coli is promising for the construction of a library of various flavonoid compounds and un-natural flavonoids in bacteria.

  20. Flavonols (kaempeferol, quercetin, myricetin) contents of selected fruits, vegetables and medicinal plants.

    Science.gov (United States)

    Sultana, Bushra; Anwar, Farooq

    2008-06-01

    The concentrations of flavonols (kaempeferol, quercetin, myricetin) were determined in 22 plant materials (9 vegetables, 5 fruits, and 8 medicinal plant organs). The materials were extracted with acidified methanol (methanol/HCl, 100:1, v/v) and analyzed by reverse phase high-performance liquid chromatographic (RP-HPLC) with UV detection. The total flavonols contents varied significantly (Paloe vera leaves contained the highest contents of flavonols (6125.6 and 1636.04mgkg(-1)), respectively, whereas, lowest was present in barks (2.42-274.07mgkg(-1)). Overall, leafy green vegetables, soft fruits and medicinal plant leaves exhibited higher levels of flavonols.

  1. Acylated flavonol glycosides from the flower of Elaeagnus angustifolia L.

    Science.gov (United States)

    Bendaikha, Sarah; Gadaut, Méredith; Harakat, Dominique; Magid, Alabdul

    2014-07-01

    Seven acylated flavonol glycosides named elaeagnosides A-G, in addition to seven known flavonoids were isolated from the flowers of Elaeagnus angustifolia. Their structures were elucidated by different spectroscopic methods including 1D, 2D NMR experiments and HR-ESI-MS analysis. In order to identify natural antioxidant and tyrosinase inhibitor agents, the abilities of these flavonoids to scavenge the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and to inhibit tyrosinase activity were evaluated. Results revealed that two of these compounds had significant anti-oxidant effect and one compound showed weak tyrosinase-inhibitory activity compared with kojic acid, quercetin, or ascorbic acid, which were used as positive control.

  2. A New Flavonol Glycoside from Anaphalis sinica Hance

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new flavonol glycoside, 5,7,3,4-tetrahydroxy-3-methoxyflavonol-3-O-β-D-glucopyranoside(1) was isolated along with quercetin(2), quercetin-3-O-α-L-rhamnopyranoside(3), quercetin-3-O-β-D-glucopyranoside(4) and kaempferol-3-O-β-D-(6"-O-p-coumaroyl)-glucopyranoside(5) from Anaphalis sinica Hance. Their structures were determined on the basis of spectral data(MS, UV, IR, 1H and 13C NMR). The structure of compound 1 was confirmed by X-ray crystallographic analysis.

  3. Flavonol 3-O-Glycosides from Three Algerian Bupleurum Species

    Directory of Open Access Journals (Sweden)

    Reguia Bencheraiet

    2012-01-01

    Full Text Available Flavonoids distribution in three algerian Bupleureum (Apiaceae species has been investigated. Quercetin (1, quercetin 3-rutinoside (2 and isorhamnetin 3-rutinoside (3 were found in the endemic species B. plantagineum Desf. Three kaempferol glycosides, kaempferol 3-glucoside (4, kaempferol 3-galactoside (5, kaempferol 3-rutinoside (6 and three quercetin glycosides, quercetin 3-rutinoside (2, quercetin 3-glucoside (7 and quercetin 3-galactoside (8, have been isolated from B. fruticosum L. while isorhamnetin (9, isorhamnetin 3-galactoside (10 and isorhamnetin 3-galactorhamnoside (11 were found in B. spinosum L. Seven flavonols are reported here for the first time from the genus.

  4. Dietary Flavonol Intake May Lower Stroke Risk in Men and Women

    NARCIS (Netherlands)

    Hollman, P.C.H.; Geelen, A.; Kromhout, D.

    2010-01-01

    Flavonols are strong antioxidants in plant foods and tea is a major dietary source. There is evidence from prospective cohort studies that tea and flavonols are inversely related to stroke incidence. We conducted a metaanalysis of prospective cohort studies to assess quantitatively the strength of

  5. Flavonols and fertilization in Petunia hybrida: localization and mode of action during pollen tube growth

    NARCIS (Netherlands)

    Ylstra, B.; Busscher, J.; Franken, J.; Hollman, P.C.H.; Mol, J.N.M.; Tunen, van A.J.

    1995-01-01

    Flavonols form an important class of flavonoids which serve an essential function during plant reproduction. Flavonoid biosynthesis is initiated by the enzyme chalcone synthase (CHS). A high abundance of flavonols and chs mRNA was demonstrated in male and female reproductive organs of Petunia hybrid

  6. Red wine is a poor source of bioavailable flavonols in men

    NARCIS (Netherlands)

    Vries, de J.H.M.; Hollman, P.C.H.; Amersfoort, van I.; Olthof, M.R.; Katan, M.B.

    2001-01-01

    Red wine is a source of polyphenolic antioxidants, of which flavonols such as quercetin are representatives. Red wine might therefore prevent LDL oxidation and atherosclerosis. However, data on the bioavailability of flavonols from wine are lacking. Therefore, we compared the bioavailability of

  7. Flavones and flavonols play distinct critical roles during nodulation of Medicago truncatula by Sinorhizobium meliloti.

    Science.gov (United States)

    Zhang, Juan; Subramanian, Senthil; Stacey, Gary; Yu, Oliver

    2009-01-01

    Flavonoids play critical roles in legume-rhizobium symbiosis. However, the role of individual flavonoid compounds in this process has not yet been clearly established. We silenced different flavonoid-biosynthesis enzymes to generate transgenic Medicago truncatula roots with different flavonoid profiles. Silencing of chalcone synthase, the key entry-point enzyme for flavonoid biosynthesis led to flavonoid-deficient roots. Silencing of isoflavone synthase and flavone synthase led to roots deficient for a subset of flavonoids, isoflavonoids (formononetin and biochanin A) and flavones (7,4'-dihydroxyflavone), respectively. When tested for nodulation by Sinorhizobium meliloti, flavonoid-deficient roots had a near complete loss of nodulation, whereas flavone-deficient roots had reduced nodulation. Isoflavone-deficient roots nodulated normally, suggesting that isoflavones might not play a critical role in M. truncatula nodulation, even though they are the most abundant root flavonoids. Supplementation of flavone-deficient roots with 7, 4'-dihydroxyflavone, a major inducer of S. meliloti nod genes, completely restored nodulation. However, the same treatment did not restore nodulation in flavonoid-deficient roots, suggesting that other non-nod gene-inducing flavonoid compounds are also critical to nodulation. Supplementation of roots with the flavonol kaempferol (an inhibitor of auxin transport), in combination with the use of flavone pre-treated S. meliloti cells, completely restored nodulation in flavonoid-deficient roots. In addition, S. meliloti cells constitutively producing Nod factors were able to nodulate flavone-deficient roots, but not flavonoid-deficient roots. These observations indicated that flavones might act as internal inducers of rhizobial nod genes, and that flavonols might act as auxin transport regulators during nodulation. Both these roles of flavonoids appear critical for symbiosis in M. truncatula.

  8. Metabolomic and genetic analyses of flavonol synthesis in Arabidopsis thaliana support the in vivo involvement of leucoanthocyanidin dioxygenase

    NARCIS (Netherlands)

    Stracke, R.; Vos, de R.C.H.; Bartelniewoehner, L.; Ishihara, H.; Sagasser, M.; Martens, S.; Weisshaar, B.

    2009-01-01

    Flavonol synthase (FLS) (EC-number 1.14.11.23), the enzyme that catalyses the conversion of flavonols into dihydroflavonols, is part of the flavonoid biosynthesis pathway. In Arabidopsis thaliana, this activity is thought to be encoded by several loci. In addition to the FLAVONOL SYNTHASE1 (FLS1) lo

  9. A New Acylated Flavonol Glycoside from Chenopodium foliosum

    Directory of Open Access Journals (Sweden)

    Zlatina Kokanova-Nedialkova, , , , , and

    2014-07-01

    Full Text Available A new acylated flavonol glycoside, namely gomphrenol-3-O-( 5 '''-O-E-feruloyl-β-D-apiofuranosyl-(1→2[β-D-glucopyranosyl-(1→6]-β-D-glucopyranoside (1 was isolated from the aerial parts of Chenopodium foliosum Asch. The structure of 1 was determined by means of spectroscopic methods (1D and 2D NMR, UV, IR, and HRESIMS. Radical scavenging and antioxidant activities of 1 were established using DPPH and ABTS radicals, FRAP assay and inhibition of lipid peroxidation (LP in linoleic acid system by the ferric thiocyanate method. Compound 1 showed low activity (DPPH and ABTS or lack of activity (FRAP and LP. In combination with CCl 4, 1 reduced the damage caused by the hepatotoxic agent and preserved cell viability and GSH level, decreased LDH leakage and reduced lipid damage. Effects were concentration dependent, most visible at the highest concentration (100 µg/m L , and similar to those of silymarin .

  10. Four New Flavonol Glycosides from the Leaves of Brugmansia suaveolens

    Directory of Open Access Journals (Sweden)

    Fabiana Geller

    2014-05-01

    Full Text Available Four new flavonol glycosides were isolated from the leaves of Brugmansia suaveolens: kaempferol 3-O-β-D-glucopyranosyl-(1'''→2''-O-α-L-arabinopyranoside (1, kaempferol 3-O-β-D-glucopyranosyl-(1'''→2''-O-α-L-arabinopyranoside-7-O-į-D-gluco-pyranoside (2, kaempferol 3-O-β-D-[6'''-O-(E-caffeoyl]-glucopyranosyl-(1'''→2''-O-α-l-arabinopyranoside-7-O-β-D-glucopyranoside (3, and kaempferol 3-O-β-D-[2'''-O-(E-caffeoyl]-glucopyranosyl-(1'''→2''-O-α-l-arabinopyranoside-7-O-β-D-glucopyranoside (4. The structure elucidation was performed by MS, 1D and 2D NMR analyses.

  11. Four new flavonol glycosides from the leaves of Brugmansia suaveolens.

    Science.gov (United States)

    Geller, Fabiana; Murillo, Renato; Steinhauser, Lisa; Heinzmann, Berta; Albert, Klaus; Merfort, Irmgard; Laufer, Stefan

    2014-05-22

    Four new flavonol glycosides were isolated from the leaves of Brugmansia suaveolens: kaempferol 3-O-β-D-glucopyranosyl-(1'''→2'')-O-α-L-arabinopyranoside (1), kaempferol 3-O-β-D-glucopyranosyl-(1'''→2'')-O-α-L-arabinopyranoside-7-O-į-D-gluco-pyranoside (2), kaempferol 3-O-β-D-[6'''-O-(E-caffeoyl)]-glucopyranosyl-(1'''→2'')-O-α-l-arabinopyranoside-7-O-β-D-glucopyranoside (3), and kaempferol 3-O-β-D-[2'''-O-(E-caffeoyl)]-glucopyranosyl-(1'''→2'')-O-α-l-arabinopyranoside-7-O-β-D-glucopyranoside (4). The structure elucidation was performed by MS, 1D and 2D NMR analyses.

  12. A new flavonol glycoside from glandless cotton seeds

    Directory of Open Access Journals (Sweden)

    Shanqin Yuan

    2012-02-01

    Full Text Available A new flavonol glycoside, namely quercetin 3-O-[α-d-apiofuranosyl(1–5-β-d-apiofuranosyl(1–2]-α-l-rhamnopyranosyl(1–6-β-d-glucopyranoside (1, was isolated from glandless cotton seeds together with the known compounds quercetin 3-O-α-l-rhamnopyranosyl(1–2-[α-l-rhamnopyranosyl(1–6]-β-d-glucopyranoside (manghaslin, 2, kaempferol 3-O-β-d-apiofruranosyl(1–2-β-d-glucopyranoside (3 and kaempferol 3-O-α-l-rhamnopyranosyl(1–6-β-d-glucopyranoside (4. It is interesting that the tetrasaccharide fragment of 1 contained both a β-apiosyl and an unusual α-apiosyl group.

  13. 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.

  14. Fluorescent analysis of interaction of flavonols with hemoglobin and bovine serum albumin

    Science.gov (United States)

    Sentchouk, V. V.; Bondaryuk, E. V.

    2007-09-01

    We have studied the fluorescent properties of flavonols (quercetin, fisetin, morin, rutin) with the aim of studying possible interaction with hemoglobin and bovine serum albumin (BSA). We observed an increase in the intensity of intrinsic fluorescence for all the flavonols except rutin in the presence of BSA. From the changes in the fluorescence spectra, we concluded that tautomeric forms are formed on interaction with hemoglobin. We determined the interconnection between the structure of related flavonols and their fluorescent properties on interaction with proteins, and we determined the binding constants for binding with BSA and hemoglobin.

  15. A new benzofuranolignan and a new flavonol derivative from the stem of Morus australis

    Institute of Scientific and Technical Information of China (English)

    Qing Jian Zhang; Di Zao Li; Ruo Yun Chen; De Quan Yu

    2008-01-01

    A new benzofuranolignan austrafuran A(1)and a new flavonol derivative 5,7,2',4'-tetrahydroxy-3-methoxyflavone(2)were isolated from the stem of Morus australis.Their structures were determined on the basis of spectroscopic evidences.

  16. The effect of growth conditions on flavonols and anthocyanins accumulation in green and red lettuce

    Directory of Open Access Journals (Sweden)

    Klaudia BRÜCKOVÁ

    2016-12-01

    Full Text Available The aim of the study was to investigate the effect of different growth conditions on anthocyanins and flavonols accumulation in leaves of green and red loose leaf lettuce (Lactuca sativa var. crispa. Lettuce plants were grown in three types of conditions, in greenhouse (I. variant, behind clear glass in field (II. variant and in open field conditions (III. variant. Estimation of anthocyanins and flavonols content was done by non-destructive measurements with optical fluorescence sensor Multiplex® 3 (Force-A, France. It was estimated that green lettuce varieties had a greater flavonols content compared to red lettuce varieties in all experimental variants. The highest level of flavonols was detected in leaves of green variety Zoltán (1.218 RU and in red lettuce had the highest amount of flavonols in variety Carmesi (1.095 RU. At the same time red lettuce varieties were characterized by higher anthocyanins content. Parameter anthocyanin index is correlated with visible red coloration of leaves. The highest content of anthocyanins was detected in variety Oakly (0.867 RU. Under the open field conditions was found statistically significant higher (P < 0.05 flavonols and anthocyanins level in both green and red lettuce leaves compared to greenhouse conditions. It may be connected with intensification of flavonoids biosynthesis and accumulation which normally stimulated by sun irradiation, especially UV-B radiation.

  17. Effect of foliar application of methyl jasmonate on flavonol-O-glycoside and some agronomic and morphological indices of chamomile (Matricaria chamomilla L. under salinity stress conditions

    Directory of Open Access Journals (Sweden)

    2016-06-01

    Full Text Available Jasmonate is a plant regulator that plays an essential role in signaling pathway and triggering the expression of plant defense-genes in response to abiotic stresses. Hence, the effect of methyl jasmonate on quantity and quality of chamomile flowers under salinity stress was investigated with a factorial experiment, based on a randomized complete blocks design with three replications, in the research greenhouse of University of Zanjan. Five concentrations of Methyl jasmonate (0, 75, 150, 225 and 300 µM was sprayed on chamomile plants which were growing under different concentrations of NaCl (2, 6, 10 and 14 dS/m. Results showed that the effects of methyl jasmonate and salinity were significant on all the traits. The highest values for plant height, total dry matter per pot, number and flower dry weight per pot and Flavonol-O-glycoside were obtained at 75 µM methyl jasmonate and salinity level of 6 dS/m. Flower yield and the amount of Flavonol-O-glycoside were decreased by increasing the salinity and methyl jasmonate concentrations over 6 dS/m and 75 µM, respectively. A significant positive correlation was revealed among all traits and dry weight of flower. Also, Flavonol-o-glycoside showed a positive and significant relationship with total dry matter per pot and flower dry weight. In general, concentration of 75 µM methyl jasmonate and salinity of 6 dS/m increased Flavonol-O-glycoside production of chamomile.

  18. Thermal Degradation of Flavonol Glycosides in Noni Leaves During Roasting

    Directory of Open Access Journals (Sweden)

    Shixin Deng

    2011-04-01

    Full Text Available Noni leaves have been used for a variety of health benefits for thousands of years. Noni leaf tea, a commercial product made by a roasting process, is attracting more attention due to its potential health benefits. Flavonoids appear to be some of the predominant constituents in noni leaves. As flavonoids exist mostly in the forms of glycosides or polymers, degradation to corresponding metabolites is usually needed for bio-absorption. This study investigates the effects of thermal treatment (non-aqueous roasting on flavonoids in noni leaves. Rutin and kaempferol glycoside contents decreased dramatically as roasting time and/or temperature increased, while quercetin and kaempferol aglycones were produced. A quantitative comparison demonstrated that quercetin and kaempferol concentrations were 3.74 and 6.28 times greater in noni leaf tea than in raw noni leaves, respectively. These findings indicate that the roasting process for the noni leaf tea could induce the degradation of flavonol glycosides, and produce their aglycone metabolites, which in turn, may lead to more beneficial bioactivities and bioavailability.

  19. Two New Flavonol Glycosides from Sarcopyramis bodinieri var. delicate

    Directory of Open Access Journals (Sweden)

    Yan Qiu

    2008-06-01

    Full Text Available Detailed chemical investigation of the herb Sarcopyramis bodinieri var. delicate resulted in the isolation of two new flavonol glycosides, namely, isorhamnetin-3-O-(6′′-OE- feruloyl-β-D-glucopyranoside (1 and isorhamnetin-3-O-(6′′-O-E-feruloyl-β-Dgalactopyranoside (2. In addition, four known compounds, quercetin-3-O-(6′′-acetyl-β-Dglucopyranoside (3, isorhamnetin-3-O-(6′′-acetyl-β-D-glucopyranoside (4, quercetin-3- O-(6′′-O-E-p-coumaroyl-β-D-glucopyranoside (5, and isorhamnetin-3-O-(6′′-O-E-pcoumaroyl- β-D-glucopyranoside (6 were obtained. The structures of the new isolates were determined by extensive spectroscopic analysis.

  20. Developmental effects on phenolic, flavonol, anthocyanin, and carotenoid metabolites and gene expression in potatoes.

    Science.gov (United States)

    Payyavula, Raja S; Navarre, Duroy A; Kuhl, Joseph; Pantoja, Alberto

    2013-07-31

    Potato phytonutrients include phenolic acids, flavonols, anthocyanins, and carotenoids. Developmental effects on phytonutrient concentrations and gene expression were studied in white, yellow, and purple potatoes. Purple potatoes contained the most total phenolics, which decreased during development (from 14 to 10 mg g(-1)), as did the activity of phenylalanine ammonia-lyase. The major phenolic, 5-chlorogenic acid (5CGA), decreased during development in all cultivars. Products of later branches of the phenylpropanoid pathway also decreased, including quercetin 3-O rutinoside, kaempferol 3-O-rutinoside, and petunidin 3-O-(p-coumaroyl)rutinoside-3-glucoside (from 6.4 to 4.0 mg g(-1)). Violaxanthin and lutein were the two most abundant carotenoids and decreased 30-70% in the yellow and white potatoes. Sucrose, which can regulate phenylpropanoid metabolism, decreased with development in all cultivars and was highest in purple potatoes. Total protein decreased by 15-30% in two cultivars. Expression of most phenylpropanoid and carotenoid structural genes decreased during development. Immature potatoes like those used in this study are marketed as "baby potatoes", and the greater amounts of these dietarily desirable compounds may appeal to health-conscious consumers.

  1. Chelation behavior of various flavonols and transfer of flavonol-chelated zinc(II) to alanylaspartic dipeptide: A PCM/DFT investigation

    Science.gov (United States)

    Yasarawan, Nuttawisit; Thipyapong, Khajadpai; Ruangpornvisuti, Vithaya

    2016-03-01

    Alanylaspartic dipeptide (AlaAsp) and zinc(II)-flavonol complex could represent a metal-binding site in proteins and a metal-ion releasing agent, respectively. Chelation of zinc(II) by either AlaAsp or flavonol ligands in aqueous solution has been examined using DFT methods with polarizable continuum model (PCM/DFT). Coordination geometry, complexation stoichiometry, coordination bond strength, preferable metal-binding site on ligands and effect of water coordination on the stability of complexes have been addressed. In several cases, the long-range corrected density functional CAM-B3LYP allows the most accurate prediction of both structural and spectroscopic data. The preferential transfer of flavonol-chelated zinc(II) to AlaAsp under solvation is attainable through the ligand-exchange reaction. The energy barrier of such reaction is significantly dependent on the degree of hydrogen bonding within the transition state. In summary, either hydroxylation or methoxylation at particular positions on the 3-hydroxyflavone backbone significantly affects the reactivity of flavonol chelates in the metal-ion transfer.

  2. Plant flavonol isorhamnetin attenuates chemically induced inflammatory bowel disease via a PXR-dependent pathway.

    Science.gov (United States)

    Dou, Wei; Zhang, Jingjing; Li, Hao; Kortagere, Sandhya; Sun, Katherine; Ding, Lili; Ren, Gaiyan; Wang, Zhengtao; Mani, Sridhar

    2014-09-01

    Isorhamnetin is an O-methylated flavonol present in fruit and vegetables. We recently reported the identification of isorhamnetin as an activator of the human pregnane X receptor (PXR), a known target for abrogating inflammation in inflammatory bowel disease (IBD). The current study investigated the role of isorhamnetin as a putative mouse PXR activator in ameliorating chemically induced IBD. Using two different models (ulcerative colitis like and Crohn's disease like) of experimental IBD in mice, we demonstrated that isorhamnetin abrogated inflammation through inhibiting the activity of myeloperoxidase, the levels of TNF-α and IL-6, the mRNA expression of proinflammatory mediators (iNOS, ICAM-1, COX2, TNF-α, IL-2 and IL-6) and the phosphorylation of IκBα and NF-κB p65. PXR gene overexpression inhibited NF-κB luciferase activity, and the inhibition was potentiated by isorhamnetin treatment. PXR knockdown by siRNA demonstrated the necessity for PXR in isorhamnetin-mediated up-regulation of xenobiotic metabolism genes. Ligand pocket-filling mutants (S247W/C284W and S247W/C284W/S208W) of human PXR weakened the effect of isorhamnetin on PXR activation. Molecular docking studies and time-resolved fluorescence resonance energy transfer competitive binding assays confirmed the ligand (isorhamnetin)-binding affinity. These results clearly demonstrated the ameliorating effect of isorhamnetin on experimental IBD via PXR-mediated up-regulation of xenobiotic metabolism and down-regulation of NF-κB signaling. The novel findings may contribute to the effective utilization of isorhamnetin or its derivatives as a PXR ligand in the treatment of human IBD.

  3. Antiviral effect of methylated flavonol isorhamnetin against influenza.

    Directory of Open Access Journals (Sweden)

    Ahmed Abdal Dayem

    Full Text Available Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3'-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1. However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B. Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70-80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids.

  4. Antiviral effect of methylated flavonol isorhamnetin against influenza.

    Science.gov (United States)

    Abdal Dayem, Ahmed; Choi, Hye Yeon; Kim, Young Bong; Cho, Ssang-Goo

    2015-01-01

    Influenza is an infectious respiratory disease with frequent seasonal epidemics that causes a high rate of mortality and morbidity in humans, poultry, and animals. Influenza is a serious economic concern due to the costly countermeasures it necessitates. In this study, we compared the antiviral activities of several flavonols and other flavonoids with similar, but distinct, hydroxyl or methyl substitution patterns at the 3, 3', and 4' positions of the 15-carbon flavonoid skeleton, and found that the strongest antiviral effect was induced by isorhamnetin. Similar to quercetin and kaempferol, isorhamnetin possesses a hydroxyl group on the C ring, but it has a 3'-methyl group on the B ring that is absent in quercetin and kaempferol. Co-treatment and pre-treatment with isorhamnetin produced a strong antiviral effect against the influenza virus A/PR/08/34(H1N1). However, isorhamnetin showed the most potent antiviral potency when administered after viral exposure (post-treatment method) in vitro. Isorhamnetin treatment reduced virus-induced ROS generation and blocked cytoplasmic lysosome acidification and the lipidation of microtubule associated protein1 light chain 3-B (LC3B). Oral administration of isorhamnetin in mice infected with the influenza A virus significantly decreased lung virus titer by 2 folds, increased the survival rate which ranged from 70-80%, and decreased body weight loss by 25%. In addition, isorhamnetin decreased the virus titer in ovo using embryonated chicken eggs. The structure-activity relationship (SAR) of isorhamnetin could explain its strong anti-influenza virus potency; the methyl group located on the B ring of isorhamnetin may contribute to its strong antiviral potency against influenza virus in comparison with other flavonoids.

  5. Flavanols and Flavonols in the Nuclei of Conifer Genotypes with Different Growth

    Directory of Open Access Journals (Sweden)

    Walter Feucht

    2014-09-01

    Full Text Available Flavanols and flavonols of mitotic and post-mitotic nuclei in needles of Taxus baccata L., Tsuga canadensis L., and slow growing dwarf genotypes of both genera are investigated histochemically. The flavanols of nuclear chromatins and in the vacuoles stain blue with the p-dimethylamino-cinnamaldehyde (DMACA reagent. Flavonols do not react with the reagent but owing to their UV absorbance they can be seen as bright yellow pigments. The nuclei in the photomicrographs obtained by microscopy were measured for flavanols at 640 nm. The vigorously sprouting Taxus baccata L. displays the most rapid cell cycling of the needles and the nuclei reveal clear blue and white mosaic structures. The flavanol component of Taxus baccata nuclei remains relatively stable most of the growing season. The dwarf genotypes also display fairly blue stained meristematic nuclei during the intense spring flush. However, after the spring flush and towards mid-summer the nuclear flavanols slowly decrease in parallel with a gradual increase in yellow staining nuclear flavonols. A mixture of blue stained flavanols and yellow flavonols results in greenish coloration of the nuclei. The greenish tint becomes more pronounced when the parenchyma cells mature and age. At the same time, the cytoplasm of the dwarf genotypes also begins to attain a more yellow tint. This trend continues towards mid-summer and autumn, particularly in the nana genotypes. It would appear that the yellow staining flavonols are linked to restricted growth conditions. In the present study, it becomes evident that the species-typical endogenous growth potential is related to both flavanol and flavonol allocation into the nuclei. The vigorously growing species of Taxus and Tsuga have a higher capacity for recruitment of flavanols into the nuclei than the very slow growing dwarf species.

  6. Plasma concentrations and urinary excretion of the antioxidant flavonols quercetin and kaempferol as biomarkers for dietary intake.

    NARCIS (Netherlands)

    Vries, de J.H.M.; Hollman, P.C.H.; Meyboom, S.; Buysman, M.N.C.P.; Zock, P.L.; Staveren, van W.A.; Katan, M.B.

    1998-01-01

    Flavonols are antioxidants that may reduce the risk of heart disease. Two major flavonols in the diet are quercetin and kaempferol, and their main sources in The Netherlands are tea and onions. We investigated whether plasma concentrations and urinary excretion of quercetin and kaempferol in humans

  7. Deconjugation and degradation of flavonol glycosides by pig cecal microbiota characterized by Fluorescence in situ hybridization (FISH)

    NARCIS (Netherlands)

    Hein, Eva-Maria; Rose, Katrin; van't Slot, Gordon; Friedrich, Alexander W; Humpf, Hans-Ulrich

    2008-01-01

    As the bioavailability of flavonoids is influenced by intestinal metabolism, we have investigated the microbial deconjugation and degradation of several flavonols and flavonol glycosides using the pig cecum in vitro model system developed in our group. For this model system the microbiota was direct

  8. DPPH radical scavenging activity of two flavonol glycosides from Aconitum napellus sp. lusitanicum.

    Science.gov (United States)

    Luis, J C; Valdés, F; Martín, R; Carmona, A J; Díaz, Jesús G

    2006-09-01

    The DPPH radical scavenging activity of two flavonol glycosides obtained from ethanolic extracts of Aconitum napellus sp. lusitanicum was studied. The results showed a high DPPH antiradical activity of compound 1 (quercetin 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranosyl-7-O-alpha-rhamnopyranoside) when compared with compound 2 (quercetin-3-sophoroside-7-rhamnopyranoside), rutin and ascorbic acid. The relationship between the caffeoyl and rhamnopyranoside groups in the flavonol glycosides structures and the DPPH antiradical activity was also discussed.

  9. Overexpression of petunia chalcone isomerase in tomato results in fruit containing increased levels of flavonols

    NARCIS (Netherlands)

    Muir, S.R.; Collins, G.J.; Robinson, S.; Hughes, S.G.; Bovy, A.G.; Vos, de C.H.R.; Tunen, van A.J.; Verhoeven, M.E.

    2001-01-01

    Tomatoes are an excellent source of the carotenoid lycopene, a compound that is thought to be protective against prostate cancer. They also contain small amounts of flavonoids in their peel (|[sim]|5–10 mg/kg fresh weight), mainly naringenin chalcone and the flavonol rutin, a quercetin glycoside. Fl

  10. 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

  11. Addition of milk does not affect the absorption of flavonols from tea in man

    NARCIS (Netherlands)

    Hollman, P.C.H.; Hof, van het K.H.; Tijburg, L.B.M.; Katan, M.B.

    2001-01-01

    Tea is a major source of flavonols, a subclass of antioxidant flavonoids present in plant foods which potentially are beneficial to human health. Milk added to tea, a frequent habit in the United Kingdom, could inhibit absorption of tea flavonoids, because proteins can bind flavonoids effectively. E

  12. Addition of milk does not affect the absorption of flavonols from tea in man

    NARCIS (Netherlands)

    Hollman, P.C.H.; Hof, van het K.H.; Tijburg, L.B.M.; Katan, M.B.

    2001-01-01

    Tea is a major source of flavonols, a subclass of antioxidant flavonoids present in plant foods which potentially are beneficial to human health. Milk added to tea, a frequent habit in the United Kingdom, could inhibit absorption of tea flavonoids, because proteins can bind flavonoids effectively.

  13. Flavonol-carbon nanostructure hybrid systems: a DFT study on the interaction mechanism and UV/Vis features.

    Science.gov (United States)

    García, Gregorio; Atilhan, Mert; Aparicio, Santiago

    2016-02-14

    Flavonols are a class of natural compounds with potential biological and pharmacological applications. They are also natural pigments responsible for the diversity of colors in plants. Flavonols offer the possibility of tuning their features through chemical functionalization as well as the presence of an aromatic backbone, which could lead to non-covalent interactions with different nanostructures or aromatic molecules. In this work, a protocol based on ONIOM (QM/QM) calculations to investigate the structural features (binding energies, intermolecular interactions) of flavonols interacting with the surface of several carbon nanostructures (such as graphene, fullerene C60 and carbon nanotubes) is developed. The confinement of flavonols inside carbon nanotubes has also been studied. Three flavonols, galangin, quercetin and myricetin, as well as pristine flavone were selected. Special attention has also been paid to the changes in UV/Vis features of flavonols due to the interaction with carbon nanostructures. Our results point out that π-stacking interactions are the driving force for the adsorption onto carbon nanostructures as well as for the confinement inside carbon nanotubes. Likewise, UV/Vis features of flavonols could be fine-tuned through the interaction with suitable carbon nanostructures.

  14. Domestication in Murtilla (Ugni molinae) Reduced Defensive Flavonol Levels but Increased Resistance Against a Native Herbivorous Insect.

    Science.gov (United States)

    Chacón-Fuentes, Manuel; Parra, Leonardo; Rodriguez-Saona, Cesar; Seguel, Ivette; Ceballos, Ricardo; Quiroz, Andres

    2015-06-01

    Plant domestication can have negative consequences for defensive traits against herbivores, potentially reducing the levels of chemical defenses in plants and consequently their resistance against herbivores. We characterized and quantified the defensive flavonols from multiple cultivated ecotypes with wild ancestors of murtilla, Ugni molinae Turcz, an endemic plant from Chile, at different times of the year, and examined their effects on a native insect herbivore, Chilesia rudis Butler (Lepidoptera: Arctiidae). We hypothesized that domestication results in a decrease in flavonol levels in U. molinae plants, and that this negatively affected C. rudis performance and preference. Ethanolic extracts were made from leaves, stems, and fruit of murtilla plants for flavonol analysis. Flavonols identified were kaempferol, quercetin, rutin, and quercetin 3-D-β-glucoside, the last two being the most abundant. More interestingly, we showed differences in flavonol composition between wild and cultivated U. molinae that persisted for most of the year. Relative amounts of all four flavonols were higher in wild U. molinae leaves; however, no differences were found in the stem and fruit between wild and cultivated plants. In choice and no-choice assays, C. rudis larvae gained more mass on, and consumed more leaf material of, wild as compared with cultivated U. molinae plants. Moreover, when applied to leaves, larvae ate more leaf material with increasing concentrations of each flavonol compound. Our study demonstrates that domestication in U. molinae reduced the amount of flavonols in leaves as well as the performance and preference of C. rudis, indicating that these compounds stimulate feeding of C. rudis. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Glucosinolates, myrosinase hydrolysis products, and flavonols found in rocket (Eruca sativa and Diplotaxis tenuifolia).

    Science.gov (United States)

    Bell, Luke; Wagstaff, Carol

    2014-05-21

    Rocket species have been shown to have very high concentrations of glucosinolates and flavonols, which have numerous positive health benefits with regular consumption. This review highlights how breeders and processors of rocket species can utilize genomic and phytochemical research to improve varieties and enhance the nutritive benefits to consumers. Plant breeders are increasingly looking to new technologies such as HPLC, UPLC, LC-MS, and GC-MS to screen populations for their phytochemical content to inform plant selections. This paper collates the research that has been conducted to date in rocket and summarizes all glucosinolate and flavonol compounds identified in the species. The paper emphasizes the importance of the broad screening of populations for phytochemicals and myrosinase degradation products, as well as unique traits that may be found in underutilized gene bank resources. This review also stresses that collaboration with industrial partners is becoming essential for long-term plant breeding goals through research.

  16. Flavonol glycosides from the aerial parts of Gynostemma pentaphyllum and their antioxidant activity.

    Science.gov (United States)

    Jang, Hari; Lee, Jin Woo; Lee, Chul; Jin, Qinghao; Lee, Myung Koo; Lee, Chong Kil; Lee, Mi Kyeong; Hwang, Bang Yeon

    2016-09-01

    The phytochemical investigation of the aerial parts of Gynostemma pentaphyllum led to the isolation of a new flavonol glycoside, gynopentaphylloside (1), along with seven known compounds (2-8). The structure of the new compound was determined on the basis of 1D, 2D NMR and HRESIMS data as well as acid hydrolysis. The antioxidant activity of the isolates was evaluated by a 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay.

  17. Flavonol glycosides and steroidal saponins from the leaves of Cestrum nocturnum and their cytotoxicity.

    Science.gov (United States)

    Mimaki, Y; Watanabe, K; Ando, Y; Sakuma, C; Sashida, Y; Furuya, S; Sakagami, H

    2001-01-01

    Phytochemical analysis of the leaves of Cestrum nocturnum (Solanaceae) resulted in the isolation of two new flavonol glycosides (1, 2) and seven steroidal saponins (3-9), including four new ones (4, 6, 7, and 9). The structures of the new compounds were determined by spectroscopic analysis, including 2D NMR data, and the results of hydrolytic cleavage. Cytotoxic activities of the isolated compounds against human oral squamous cell carcinoma-(HSC-2) cells and normal human gingival fibroblasts are reported.

  18. Plant flavonol isorhamnetin attenuates chemically induced inflammatory bowel disease via a PXR-dependent pathway

    OpenAIRE

    Dou, Wei; Zhang, Jingjing; Li, Hao; Kortagere, Sandhya; Sun, Katherine; Ding, Lili; Ren, Gaiyan; Wang, Zhengtao; Mani, Sridhar

    2014-01-01

    Isorhamnetin is an O-methylated flavonol present in fruit and vegetables. We recently reported the identification of isorhamnetin as an activator of the human pregnane X receptor (PXR), a known target for abrogating inflammation in inflammatory bowel disease (IBD). The current study investigated the role of isorhamnetin as a putative mouse PXR activator in ameliorating chemically induced IBD. Using two different models (Ulcerative colitis-like and Crohn’s disease-like) of experimental IBD in ...

  19. Two new acylated flavonol glycosides from Mimosa pigra L. leaves sub-family Mimosoideae

    Directory of Open Access Journals (Sweden)

    Chinedu J. Okonkwo

    2016-12-01

    Conclusion: Myricetin, quercetin and their glycoside derivatives are strong antioxidants; and elicit cytotoxic effect on human cancer cell lines among other pharmacological activities. The isolation of acylated flavonoids in M. pigra provided an important insight on the evolutionary trend of the medicinal plant. While the dominance of flavonols, may account for the various ethnomedicinal uses of the herb and the mechanism and mode of its confirmed pharmacological actions.

  20. Two 8C-methylated Flavonols from the Leaves of Vellozia candida Mikan (Velloziaceae

    Directory of Open Access Journals (Sweden)

    Branco Alexsandro

    2002-01-01

    Full Text Available From the leaves of Vellozia candida Mikan (Velloziaceae the new flavonol 3',4',5,7-tetrahydroxy-3,6-dimethoxy-8-methylflavone and its known 7-O-methyl derivative, 3',4',5-trihydroxy-3,6,7-trimethoxy-8-methylflavone, were isolated and characterized by spectral data, including 2D NMR and tandem mass spectrometry experiments. The 5-hydroxy-3,3',4',6,7-pentamethoxy-8-methylflavone derivative was obtained by methylation with diazomethane.

  1. Influence of domestic processing and storage on flavonol contents in berries.

    Science.gov (United States)

    Häkkinen, S H; Kärenlampi, S O; Mykkänen, H M; Törrönen, A R

    2000-07-01

    Effects of domestic processing and storage on the flavonols quercetin, myricetin, and kaempferol in five berries were studied using an optimized RP-HPLC method with UV and diode array detection after an acid hydrolysis of the corresponding glycosides. In fresh berries, the total content of flavonols was highest in lingonberry (169 mg/kg) and black currant (157 mg/kg), intermediate in bilberry (41 mg/kg) and strawberry (17 mg/kg), and lowest in red raspberry (9.5 mg/kg). Cooking strawberries with sugar to make jam resulted in minor losses (quercetin 15%, kaempferol 18%). During cooking of bilberries with water and sugar to make soup, 40% of quercetin was lost. Traditional preservation of crushed lingonberries in their own juice caused a considerable (40%) loss of quercetin. Only 15% of quercetin and 30% of myricetin present in unprocessed berries were retained in juices made by common domestic methods (steam-extracted black currant juice, unpasteurized lingonberry juice). Cold-pressing was superior to steam-extraction in extracting flavonols from black currants. During 9 months of storage at 20 C, quercetin content decreased markedly (40%) in bilberries and lingonberries, but not in black currants or red raspberries. Myricetin and kaempferol were more susceptible than quercetin to losses during storage.

  2. Genetic Variation of Flavonols Quercetin, Myricetin, and Kaempferol in the Sri Lankan Tea (Camellia sinensis L.) and Their Health-Promoting Aspects

    Science.gov (United States)

    Jeganathan, Brasathe; Kottawa-Arachchi, J. Dananjaya; Ranatunga, Mahasen A. B.; Abeysinghe, I. Sarath B.; Gunasekare, M. T. Kumudini; Bandara, B. M. Ratnayake

    2016-01-01

    Flavonol glycosides in tea leaves have been quantified as aglycones, quercetin, myricetin, and kaempferol. Occurrence of the said compounds was reported in fruits and vegetable for a long time in association with the antioxidant potential. However, data on flavonols in tea were scanty and, hence, this study aims to envisage the flavonol content in a representative pool of accessions present in the Sri Lankan tea germplasm. Significant amounts of myricetin, quercetin, and kaempferol have been detected in the beverage type tea accessions of the Sri Lankan tea germplasm. This study also revealed that tea is a good source of flavonol glycosides. The Camellia sinensis var. sinensis showed higher content of myricetin, quercetin, and total flavonols than var. assamica and ssp. lasiocalyx. Therefore flavonols and their glycosides can potentially be used in chemotaxonomic studies of tea germplasm. The nonbeverage type cultivars, especially Camellia rosaflora and Camellia japonica Red along with the exotic accessions resembling China type, could be useful in future germplasm studies because they are rich sources of flavonols, namely, quercetin and kaempferol, which are potent antioxidants. The flavonol profiles can be effectively used in choosing parents in tea breeding programmes to generate progenies with a wide range of flavonol glycosides. PMID:27366737

  3. Genetic Variation of Flavonols Quercetin, Myricetin, and Kaempferol in the Sri Lankan Tea (Camellia sinensis L. and Their Health-Promoting Aspects

    Directory of Open Access Journals (Sweden)

    Brasathe Jeganathan

    2016-01-01

    Full Text Available Flavonol glycosides in tea leaves have been quantified as aglycones, quercetin, myricetin, and kaempferol. Occurrence of the said compounds was reported in fruits and vegetable for a long time in association with the antioxidant potential. However, data on flavonols in tea were scanty and, hence, this study aims to envisage the flavonol content in a representative pool of accessions present in the Sri Lankan tea germplasm. Significant amounts of myricetin, quercetin, and kaempferol have been detected in the beverage type tea accessions of the Sri Lankan tea germplasm. This study also revealed that tea is a good source of flavonol glycosides. The Camellia sinensis var. sinensis showed higher content of myricetin, quercetin, and total flavonols than var. assamica and ssp. lasiocalyx. Therefore flavonols and their glycosides can potentially be used in chemotaxonomic studies of tea germplasm. The nonbeverage type cultivars, especially Camellia rosaflora and Camellia japonica Red along with the exotic accessions resembling China type, could be useful in future germplasm studies because they are rich sources of flavonols, namely, quercetin and kaempferol, which are potent antioxidants. The flavonol profiles can be effectively used in choosing parents in tea breeding programmes to generate progenies with a wide range of flavonol glycosides.

  4. Flavonols modulate the effector functions of healthy individuals' immune complex-stimulated neutrophils: a therapeutic perspective for rheumatoid arthritis.

    Science.gov (United States)

    Santos, Everton O L; Kabeya, Luciana M; Figueiredo-Rinhel, Andréa S G; Marchi, Larissa F; Andrade, Micássio F; Piatesi, Fabiana; Paoliello-Paschoalato, Adriana B; Azzolini, Ana Elisa C S; Lucisano-Valim, Yara M

    2014-07-01

    Rheumatoid arthritis (RA) patients usually exhibit immune complex (IC) deposition and increased neutrophil activation in the joint. In this study, we assessed how four flavonols (galangin, kaempferol, quercetin, and myricetin) modulate the effector functions of healthy individuals' and active RA patients' IC-stimulated neutrophils. We measured superoxide anion and total reactive oxygen species production using lucigenin (CL-luc)- and luminol (CL-lum)-enhanced chemiluminescence assays, respectively. Galangin, kaempferol, and quercetin inhibited CL-lum to the same degree (mean IC50=2.5 μM). At 2.5 μM, quercetin and galangin suppressed nearly 65% CL-lum of active RA patients' neutrophils. Quercetin inhibited CL-luc the most effectively (IC50=1.71±0.36 μM). The four flavonols diminished myeloperoxidase activity, but they did not decrease NADPH oxidase activity, phagocytosis, microbial killing, or cell viability of neutrophils. The ability of the flavonols to scavenge hypochlorous acid and chloramines, but not H2O2, depended on the hydroxylation degree of the flavonol B-ring. Therefore, at physiologically relevant concentrations, the flavonols partially inhibited the oxidative metabolism of IC-stimulated neutrophils without affecting the other investigated effector functions. Using these compounds to modulate IC-mediated neutrophil activation is a promising safe therapeutic strategy to control inflammation in active RA patients.

  5. Metal and flavonol contents of Moringa oleifera grown in South Africa

    Directory of Open Access Journals (Sweden)

    Vusumzi Pakade

    2013-03-01

    Full Text Available Moringa (Moringa oleifera is a plant that is commonly consumed as a nutritional supplement by some communities in South Africa. Contamination of moringa with toxic heavy metals could be deadly for consumers. However, some metal elements are essential for consumers in trace amounts. We therefore investigated the concentrations of heavy metals, including major and trace nutrient elements, in the soil and in the leaves and flowers of moringa grown on two farms in South Africa. After total digestion in the microwave, the concentrations of metals were determined using inductively coupled plasma optical emission spectroscopy. No toxic heavy metals were detected in the leaves and flowers of moringa. On average, moringa contained higher concentrations of Ca (18 500 mg/kg and Mg (5500 mg/kg than selected vegetables (spinach, cabbage, cauliflower, broccoli and peas. The concentrations of other major nutrients in moringa were similar to those of the vegetables. Based on reports of antioxidant activity, we also investigated the concentrations of flavonols (myricetin, quercetin, kaempferol in moringa leaves and flowers in comparison with the selected vegetables. A high concentration of flavonols is related to antioxidant activity. Plant and vegetable materials were extracted under reflux using an acidified methanol (1% HCl solution and the flavonols were identified and quantified using reverse-phased high-performance liquid chromatography with UV detection. Moringa leaves had higher concentrations of myricetin (1296.6 mg/kg, quercetin (1362.6 mg/kg and kaempferol (1933.7 mg/kg than vegetables (spinach: myricetin 620.0 mg/kg, quercetin 17.9 mg/kg, kaempferol 215.3 mg/kg. No major differences were found between the plants growing on the two farms. Moringa is thus nutritionally valuable and safe to consume.

  6. A new flavonol glucoside from the aerial parts of Sida glutinosa.

    Science.gov (United States)

    Das, Niranjan; Achari, Basudev; Harigaya, Yoshihiro; Dinda, Biswanath

    2011-10-01

    Phytochemical investigation on the dried aerial parts of Sida glutinosa has led to the isolation of a new flavonol glucoside, glutinoside (1), along with seven known compounds, 24(28)-dehydromakisterone A (2), 1,2,3,9-tetrahydropyrrolo[2,1-b]-quinazolin-3-amine (3), docosanoic acid, 1-triacontanol, campesterol, stigmasterol, and β-sitosterol. The structures of these compounds were elucidated by means of extensive spectroscopic techniques as well as GC/MS analysis (for sterols) and comparison with the literature data. All these seven known compounds are reported from this plant for the first time.

  7. Anti-inflammatory activity of a novel flavonol glycoside from the Bauhinia variegata Linn.

    Science.gov (United States)

    Yadava, R N; Reddy, V Madhu Sudhan

    2003-06-01

    Bauhinia variegata Linn. (Leguminosae) is commonly known as 'Kachnar' in Hindi. It is distributed almost throught India. Its powdered bark is traditionally used for tonic, astrain, ulcers. It is also useful in skin diseases. The roots are used as antidote to snake poison. The present article deals with the isolation and structural elucidation of a novel flavonol glycoside 5,7,3',4'-tetrahydroxy-3-methoxy-7-O-alpha-L-rhamnopyranosyl(1-->3)-O-beta-galactopyranoside (1) from the roots of Bauhinia Variegata and its structure was identified by spectral analysis and chemical degradations. The novel compound (1) showed anti-inflammatory activity.

  8. Chemical Components of Helicia nilagirica Beed. I. Structure of Three New Flavonol Glycosides

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Three new flavonol glycosides were isolated from the leaves of Helicia nilagirica Beed.. The structures were elucidated as kaempferol-3-O-β-D-xylopyranosyl-(1→6)-β-D-glyco- pyranosyl-(1→2)-α-L-rhamnopyranoside, quercetin-3-O-β-D-xylopyranosyl-(1→6)-β-D-glycopy- ranosyl-(1→2)-[-β-D-xylopyranosyl-(1→4)]-α-L-rhamnopyranoside, and quercetin-3-O-β-D- xylopyranosyl-(1→6)-α-D-glycopyranosyl-(1→2)-α-L-rhamnopyranoside, named as Helicianeoside A、B and C, respectively.

  9. Antioxidant activities and structural characterization of flavonol O-glycosides from seeds of Japanese horse chestnut (Aesculus turbinata BLUME).

    Science.gov (United States)

    Kimura, Hideto; Ogawa, Satoshi; Ishihara, Tomoe; Maruoka, Mahoko; Tokuyama-Nakai, Shota; Jisaka, Mitsuo; Yokota, Kazushige

    2017-08-01

    We attempted to evaluate the contents and distribution of antioxidants in the whole seeds, seed shells, and peeled seeds of the Japanese horse chestnut. The seed shells exhibited the highest antioxidant activities due to the presence of highly polymeric proanthocyanidins as we have reported recently. On the other hand, the peeled seeds predominantly contained flavonols such as quercetin and kaempferol at a high level of 66.7% of total polyphenols, also contributing to the predominant antioxidant activities. The instrumental analysis of the extract from the whole seeds revealed the identification of eight flavonol O-glycosides, including six compounds with quercetin and two species with kaempferol as aglycones. The isolated species exhibited different antioxidant activities depending on the types of aglycones, glycosides, and acylated moieties. The results indicate that the peeled seeds are a good source of flavonol O-glycosides serving as antioxidants to be used for food additives and dietary supplements. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Molecular imprinted polymer for solid-phase extraction of flavonol aglycones from Moringa oleifera extracts.

    Science.gov (United States)

    Pakade, Vusumzi; Cukrowska, Ewa; Lindahl, Sofia; Turner, Charlotta; Chimuka, Luke

    2013-02-01

    Molecular imprinted polymer produced using quercetin as the imprinting compound was applied for the extraction of flavonol aglycones (quercetin and kaempferol) from Moringa oleifera methanolic extracts obtained using heated reflux extraction method. Identification and quantification of these flavonols in the Moringa extracts was achieved using high performance liquid chromatography with ultra violet detection. Breakthrough volume and retention capacity of molecular imprinted polymer SPE was investigated using a mixture of myricetin, quercetin and kaempferol. The calculated theoretical number of plates was found to be 14, 50 and 8 for myricetin, quercetin and kaempferol, respectively. Calculated adsorption capacities were 2.0, 3.4 and 3.7 μmol/g for myricetin, quercetin and kaempferol, respectively. No myricetin was observed in Moringa methanol extracts. Recoveries of quercetin and kaempferol from Moringa methanol extracts of leaves and flowers ranged from 77 to 85% and 75 to 86%, respectively, demonstrating the feasibility of using the developed molecularly imprinted SPE method for quantitative clean-up of both of these flavonoids. Using heated reflux extraction combined with molecularly imprinted SPE, quercetin concentrations of 975 ± 58 and 845 ± 32 mg/kg were determined in Moringa leaves and flowers, respectively. However, the concentrations of kaempferol found in leaves and flowers were 2100 ± 176 and 2802 ± 157 mg/kg, respectively. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Genetic effects of the flavonols quercetin, kaempferol, and galangin on Chinese hamster ovary cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Carver, J.H. (Lawrence Livermore National Lab., Livermore, CA); Carrano, A.V.; MacGregor, J.T.

    1983-01-01

    The genotoxicity of selected flavonols was evaluated by multiple endpoints in Chinese hamster ovary (CHO) cells. Chromosomal aberrations, sister-chromatid exchange (SCE), and forward mutation at 4 gene loci were measured in a single population of cells exposed to quercetin, kaempferol, or galangin for 15 h with and without metabolic activation. The incidence of chromosomal aberrations was significantly increased by quercetin in the absence of activation and by kaempferol and galangin with and without activation. Flavanol treatment affected SCE and mutation at the hgprt, aprt, or Na/sup +//K/sup +/-ATPase loci only marginally, but significantly increased mutation frequencies at the tk locus. The response at the tk locus suggests that the CHO cells may behave similarly to L5178Y cells, in which the tk locus is thought to reflect chromosomal lesions in addition to point mutation. These results indicate that, at least under the conditions examined, flavonols induce chromosomal aberrations in CHO cells, but have little effect on point mutation or SCE.

  12. Experimental and theoretical investigation effect of flavonols antioxidants on DNA damage.

    Science.gov (United States)

    Ensafi, Ali A; Heydari-Soureshjani, E; Jafari-Asl, M; Rezaei, B; Ghasemi, Jahan B; Aghaee, Elham

    2015-08-01

    A new electrochemical biosensor was developed to demonstrate the effect of Acridine Orange (AO) on DNA damage. Then, the biosensor was used to check the inhibitors effect of three flavonols antioxidants (myricetin, fisetin and kaempferol) on DNA damage. Acridine Orange (AO) was used as a damaging agent because it shows a high affinity to nucleic acid and stretch of the double helical structure of DNA. Decreasing on the oxidation signals of adenine and guanine (in the DNA) in the presence of AO were used as probes to study the antioxidants power, using DNA-modified screen printed graphene electrode (DNA/SPGE). The results of our study showed that the DNA-biosensor could be suitable biosensor to investigate the inhibitors ability of the flavonols antioxidants on the DNA damage. The linear dependency was detected in the two regions in the ranges of 1.0-15.0 and 15.0-500.0 pmol L(-1). The detection limit was found 0.5 pmol L(-1) and 0.6 pmol L(-1) for guanine and adenine, respectively. To confirm the electrochemical results, Uv-Vis and fluorescence spectroscopic methods were used too. Finally molecular dynamic (MD) simulation was performed on the structure of DNA in a water box to study any interaction between the antioxidant, AO and DNA.

  13. Protective effects of red wine flavonols on 4-hydroxynonenal-induced apoptosis in PC12 cells.

    Science.gov (United States)

    Jang, Young Jin; Kang, Nam Joo; Lee, Ki Won; Lee, Hyong Joo

    2009-08-01

    There is accumulating evidence that a moderate consumption of red wine has health benefits, such as the inhibition of neurodegenerative diseases. Although this is generally attributed to resveratrol, the protective mechanisms and the active substance(s) remain unclear. We examined whether and how red wine extract (RWE) and red wine flavonols quercetin and myricetin inhibited 4-hydroxynonenal (HNE)-induced apoptosis of rat pheochromocytoma PC12 cells. RWE attenuated HNE-induced PC12 cell death in a dose-dependent manner. HNE induced cleavage of poly(ADP-ribose) polymerase, which is involved in DNA repair in the nucleus, and this was inhibited by RWE treatment. Treatment with RWE also inhibited HNE-induced nuclear condensation in PC12 cells. Data of 2',7'-dichlorofluorescin diacetate showed that RWE protected against apoptosis of PC12 cells by attenuating intracellular reactive oxygen species. The cytoprotective effects on HNE-induced cell death were stronger for quercetin and myricetin than for resveratrol. HNE-induced nuclear condensation was attenuated by quercetin and myricetin. These results suggest that the neuroprotective potential of red wine is attributable to flavonols rather than to resveratrol.

  14. Dietary Intakes of Individual Flavanols and Flavonols Are Inversely Associated with Incident Type 2 Diabetes in European Populations123

    DEFF Research Database (Denmark)

    Zamora-Ros, Raul; Forouhi, Nita G.; Sharp, Stephen J.

    2014-01-01

    Dietary flavanols and flavonols, flavonoid subclasses, have been recently associated with a lower risk of type 2 diabetes (T2D) in Europe. Even within the same subclass, flavonoids may differ considerably in bioavailability and bioactivity. We aimed to examine the association between individual f...

  15. High-Flavonol Tomatoes Through Heterologous Expression of the Maize Transcription Factor Genes LC and C1

    NARCIS (Netherlands)

    Bovy, A.; Vos, de R.; Kemper, M.; Schijlen, E.; Almenar Pertejo, M.; Muir, S.; Collins, G.; Robinson, S.; Verhoeyen, M.; Hughes, S.; Santos-Buelga, C.; Tunen, van A.

    2002-01-01

    Flavonoids are a group of polyphenolic plant secondary metabolites important for plant biology and human nutrition. In particular flavonols are potent antioxidants, and their dietary intake is correlated with a reduced risk of cardiovascular diseases. Tomato fruit contain only in their peel small am

  16. Dietary intakes of individual flavanols and flavonols are inversely associated with incident type 2 diabetes in European populations

    NARCIS (Netherlands)

    Zamora-Ros, R.; Forouhi, N.G.; Sharp, S.J.; Gonzalez, C.A.; Buijsse, B.; Schouw, van der Y.T.; Boeing, H.; Feskens, E.J.M.; Woudenbergh, van G.J.

    2014-01-01

    Dietary flavanols and flavonols, flavonoid subclasses, have been recently associated with a lower risk of type 2 diabetes (T2D) in Europe. Even within the same subclass, flavonoids may differ considerably in bioavailability and bioactivity. We aimed to examine the association between individual flav

  17. A general approach to quantification of hydroxycinnamic acid derivatives and flavones, flavonols, and their glycosides by UV spectrophotometry

    Science.gov (United States)

    A general method was developed for the quantification of hydroxycinnamic acid derivatives and flavones, flavonols, and their glycosides based on the UV molar relative response factors (MRRF) of the standards. Each of these phenolic compounds contains a cinnamoyl structure and has a maximum absorban...

  18. Expression of genes involved in anthocyanin biosynthesis in relation to anthocyanin, proanthocyanidin, and flavonol levels during bilberry fruit development.

    Science.gov (United States)

    Jaakola, Laura; Määttä, Kaisu; Pirttilä, Anna Maria; Törrönen, Riitta; Kärenlampi, Sirpa; Hohtola, Anja

    2002-10-01

    The production of anthocyanins in fruit tissues is highly controlled at the developmental level. We have studied the expression of flavonoid biosynthesis genes during the development of bilberry (Vaccinium myrtillus) fruit in relation to the accumulation of anthocyanins, proanthocyanidins, and flavonols in wild berries and in color mutants of bilberry. The cDNA fragments of five genes from the flavonoid pathway, phenylalanine ammonia-lyase, chalcone synthase, flavanone 3-hydroxylase, dihydroflavonol 4-reductase, and anthocyanidin synthase, were isolated from bilberry using the polymerase chain reaction technique, sequenced, and labeled with a digoxigenin-dUTP label. These homologous probes were used for determining the expression of the flavonoid pathway genes in bilberries. The contents of anthocyanins, proanthocyanidins, and flavonols in ripening bilberries were analyzed with high-performance liquid chromatography-diode array detector and were identified using a mass spectrometry interface. Our results demonstrate a correlation between anthocyanin accumulation and expression of the flavonoid pathway genes during the ripening of berries. At the early stages of berry development, procyanidins and quercetin were the major flavonoids, but the levels decreased dramatically during the progress of ripening. During the later stages of ripening, the content of anthocyanins increased strongly and they were the major flavonoids in the ripe berry. The expression of flavonoid pathway genes in the color mutants of bilberry was reduced. A connection between flavonol and anthocyanin synthesis in bilberry was detected in this study and also in previous data collected from flavonol and anthocyanin analyses from other fruits. In accordance with this, models for the connection between flavonol and anthocyanin syntheses in fruit tissues are presented.

  19. New flavonol glycosides from the flowers of Aconitum napellus ssp. tauricum.

    Science.gov (United States)

    Fico, G; Braca, A; Bilia, A R; Tomè, F; Morelli, I

    2001-04-01

    From the methanolic extract of the flowers of A. napellus spp. tauricum four new flavonol glycosides: quercetin 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7- O-alpha-rhamnopyranoside (1), kaempferol 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta- glucopyranoside-7-O-alpha-rhamnopyranoside (2), quercetin 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta- glucopyranoside-7-O-alpha-rhamnopyranoside (3), and kaempferol 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta- glucopyranoside-7-O-alpha-rhamnopyranoside (4), together with the known beta-3,4-dihydroxyphenethyl beta-glucopyranoside were isolated. The structural elucidation of all compounds was deduced on the basis of 1H- and 13C-NMR spectral data, including those derived from 2D-NMR, as well as on HPLC-MS results.

  20. Fluorescence studies of interaction between flavonol p-coumaroylglucoside tiliroside and bovine serum albumin

    Science.gov (United States)

    Hu, Xiaoli; Cui, Shuya; Liu, Jia qin

    2010-10-01

    In this paper, the interaction between flavonol p-coumaroylglucoside tiliroside and BSA was investigated by fluorescence quenching spectra, synchronous fluorescence spectra, and three-dimensional fluorescence spectra under simulative physiological conditions. It was proved that the fluorescence quenching of BSA by tiliroside was mainly a result of the formation of a tiliroside-BSA complex. The modified Stern-Volmer quenching constant and the corresponding thermodynamic parameters Δ H, Δ G and Δ S at different temperatures were calculated. The results indicated that electrostatic interactions were the predominant intermolecular forces in stabilizing the complex. The distance r = 3.95 nm between the donor (BSA) and acceptor (tiliroside) was obtained according to Förster's nonradioactive energy transfer theory. The synchronous fluorescence and three-dimensional fluorescence spectra results showed the microenvironment and conformation of BSA were changed in the binding reaction.

  1. Additional antiprotozoal flavonol glycosides of the aerial parts of Helianthemum glomeratum.

    Science.gov (United States)

    Calzada, Fernando; Alanís, Alma Delia

    2007-01-01

    Bioassay-guided fractionation of the methanol extract of aerial parts from Helianthemum glomeratum afforded five antiprotozoal flavonol glycosides: tiliroside, kaempferol-3-O-(3'',6''di-O-E-p-coumaroyl)-betad-glucopyranoside, astragalin, quercitrin and isoquercitrin. The in vitro antiprotozoal assay showed that tiliroside was the most potent antiamoebic and antigiardial compound with IC(50) values of 17.5 microg/mL for Entamoeba histolytica and 17.4 microg/mL for G. lamblia. Isoquercitrin showed selectivity against E. histolytica (IC(50) 14.7 microg/mL) and quercitrin toward G. lamblia (IC(50) 24.3 microg/mL). All isolated compounds were less active than metronidazole and emetine, two antiprotozoal drugs used as positive controls.

  2. A flavonol triglycoside and investigation of the antioxidant and cell stimulating activities of Annona muricata Linn.

    Science.gov (United States)

    Nawwar, Mahmoud; Ayoub, Nahla; Hussein, Sahar; Hashim, Amani; El-Sharawy, Reham; Wende, Kristian; Harms, Manuela; Lindequist, Ulrike

    2012-05-01

    Chemical investigation on leaves of Annona muricata resulted in the isolation of the flavonol triglycoside, quercetin 3-O-α-rhamnosyl-(1″″ → 6″)-β-sophoroside, together with twelve known phenolics. The structures of these compounds were established by 1D- and 2D-nuclear magnetic resonance spectroscopic techniques and mass spectrometry data. The in vitro antioxidant studies of the investigated aqueous ethanol extract and its column fractions were accomplished using the oxygen radical absorbance capacity (ORAC) method. A stimulating effect on HaCaT human keratinocytes by the leaf extract was also assessed. Il-6 production after UV irradiation was not influenced by A. muricata leaf extract.

  3. Allometric analysis of the induced flavonols on the leaf surface of wild tobacco (Nicotiana attenuata).

    Science.gov (United States)

    Roda, Amy L; Oldham, Neil J; Svatos, Ales; Baldwin, Ian T

    2003-02-01

    Trichomes excrete secondary metabolites that may alter the chemical composition of the leaf surface, reducing damage caused by herbivores, pathogens and abiotic stresses. We examined the surface exudates produced by Nicotiana attenuata Torr. Ex Wats., a plant known to contain and secrete a number of secondary metabolites that are toxic or a deterrent to herbivorous insects. Extractions specific to the leaf surface, the trichomes, and the laminar components demonstrated the localization of particular compounds. Diterpene glycosides occurred exclusively in leaf mesophyll, whereas nicotine was found in both the trichomes and mesophyll. Neither rutin nor nicotine was found on the leaf surface. Quercetin and 7 methylated derivatives were found in the glandular trichomes and appeared to be excreted onto the leaf surface. We examined the elicitation of these flavonols on the leaf surface with a surface-area allometric analysis, which measures changes in metabolites independent of the effects of leaf expansion. The flavonols responded differently to wounding, methyl jasmonate (MeJA), herbivore attack and UV-C radiation, and the response patterns corresponded to their compound-specific allometries. Finding greater amounts of quercetin on younger leaves and reduced amounts after herbivore feeding and MeJA treatment, we hypothesized that quercetin may function as an attractant, helping the insects locate a preferred feeding site. Consistent with this hypothesis, mirids (Tupiocoris notatus) were found more often on mature leaves sprayed with quercetin at a concentration typical of young leaves than on unsupplemented mature leaves. The composition of metabolites on the leaf surface of N. attenuata changes throughout leaf development and in response to herbivore attack or environmental stress, and these changes are mediated in part by responses of the glandular trichomes.

  4. Advanced Knowledge of Three Important Classes of Grape Phenolics: Anthocyanins, Stilbenes and Flavonols

    Directory of Open Access Journals (Sweden)

    Luigi Bavaresco

    2013-09-01

    Full Text Available Grape is qualitatively and quantitatively very rich in polyphenols. In particular, anthocyanins, flavonols and stilbene derivatives play very important roles in plant metabolism, thanks to their peculiar characteristics. Anthocyanins are responsible for the color of red grapes and wines and confer organoleptic characteristics on the wine. They are used for chemotaxonomic studies and to evaluate the polyphenolic ripening stage of grape. They are natural colorants, have antioxidant, antimicrobial and anticarcinogenic activity, exert protective effects on the human cardiovascular system, and are used in the food and pharmaceutical industries. Stilbenes are vine phytoalexins present in grape berries and associated with the beneficial effects of drinking wine. The principal stilbene, resveratrol, is characterized by anticancer, antioxidant, anti-inflammatory and cardioprotective activity. Resveratrol dimers and oligomers also occur in grape, and are synthetized by the vine as active defenses against exogenous attack, or produced by extracellular enzymes released from pathogens in an attempt to eliminate undesirable toxic compounds. Flavonols are a ubiquitous class of flavonoids with photo-protection and copigmentation (together with anthocyanins functions. The lack of expression of the enzyme flavonoid 3',5'-hydroxylase in white grapes restricts the presence of these compounds to quercetin, kaempferol and isorhamnetin derivatives, whereas red grapes usually also contain myricetin, laricitrin and syringetin derivatives. In the last ten years, the technological development of analytical instrumentation, particularly mass spectrometry, has led to great improvements and further knowledge of the chemistry of these compounds. In this review, the biosynthesis and biological role of these grape polyphenols are briefly introduced, together with the latest knowledge of their chemistry.

  5. Dietary Flavonols Intake and Risk of Esophageal and Gastric Cancer: A Meta-Analysis of Epidemiological Studies

    Directory of Open Access Journals (Sweden)

    Yan Xie

    2016-02-01

    Full Text Available Background: Esophageal cancer (EC and gastric cancer (GC are common cancers and leading causes of cancer deaths worldwide. Many studies have investigated the association between dietary flavonols intake and the risk of EC and GC, but the results are inconsistent. Hence, we conducted a systematic analysis of relevant population-based studies to assess the association and derive a more precise estimation. Methods: The Cochrane, PubMed and Embase databases were searched to identify articles published through January 2016 that met the predetermined inclusion criterion. Twelve studies involving 4593 patients and 519,378 controls were included. Results: The summary odds ratios (ORs of EC, GC and the two combined were respectively 0.88 (95% CI: 0.73–1.08, 0.80 (95% CI: 0.70–0.91 and 0.83 (95% CI: 0.74–0.92 for the highest category of dietary flavonols intake compared with the lowest. No significant heterogeneities were observed in these studies. Further analysis showed that the pooled ORs of EC and GC for cohort, population-based case-control and hospital-based case-control studies were 0.90 (95% CI: 0.61–1.34, 0.92 (95% CI: 0.72–1.18, 0.68 (95% CI: 0.38–1.24 and 0.83 (95% CI: 0.65–1.06, 0.84 (95% CI: 0.45–1.59, 0.70 (95% CI: 0.56–0.88. The subgroup analyses revealed a significant association of flavonol intake with a reduced risk of noncardia gastric adenocarcinoma but not gastric cardia adenocarcinoma. Moreover, significant inverse associations of flavonol intake with GC risk were observed in women but not in men, in smokers but not in nonsmokers, in European populations but not in American populations. Similarly, a significant inverse association of flavonols intake with EC risk was also observed in smokers but not in nonsmokers. Conclusion: High intake of dietary flavonols is significantly related to a reduced risk of GC, especially in women and smokers.

  6. Synergistic effect of flavones and flavonols against herpes simplex virus type 1 in cell culture. Comparison with the antiviral activity of propolis.

    Science.gov (United States)

    Amoros, M; Simões, C M; Girre, L; Sauvager, F; Cormier, M

    1992-12-01

    The in vitro activity against herpes simplex virus type 1 of the major flavonoids identified in propolis was investigated. Flavonols were found to be more active than flavones, the order of importance being galangin, kaempferol, and quercetin. The efficacy against HSV-1 of binary flavone-flavonol combinations has been also investigated. The synergy demonstrated by all combinations could explain why propolis is more active than its individual compounds.

  7. [Determination of flavonol glycosides in tea samples by ultra-high performance liquid chromatography-photodiode array detection-tandem mass spectrometry].

    Science.gov (United States)

    Wang, Zhicong; Sha, Yuebing; Yu, Xiaobo; Liang, Yuerong

    2015-09-01

    An ultra-high performance liquid chromatography-photodiode array detection-tandem mass spectrometry (UPLC-PDA-MS/MS) method was developed for the determination of flavonol glycosides in tea samples. The chromatographic separation was performed on an UPLC HSS T3 column by gradient elution with the mobile phases of acetonitrile and water both containing 0.1% (v/v) formic acid. A total of 15 flavonol glycosides which include 3 myricetin glycosides, 6 quercetin glycosides and 6 kaempferol glycosides were positively identified in green and black tea samples by comparing the retention times and mass spectra of the samples with standards and publications. The quantities of flavonol glycosides were relatively calculated with the stand- ard quercetin-3-rhamnosylglucoside (Q-GRh) which was calibrated with external quantification method using multi-reaction monitoring (MRM) mode. The results showed that there were different flavonol glycoside distributions in green tea and black tea. The total amount of flavonol glycosides in green tea was 1. 7 times of that in black tea. The major flavonol glycosides in green tea were myricetin-3-galactoside (M-Ga), myricetin-3-glucoside (M-G), quercetin-3-glucosyl-rhamnosyl-galactoside (Q-GaRhG), quercetin-3-glucosyl-rhamnosyl-glucoside (Q-GRhG), kaempferol-3-glucosyl-rhamnosyl-galactoside (K-GaRhG) and kaempferol-3-glucosyl- rhamnosyl-glucoside (K-GRhG), but for black tea, the major flavonol glycosides were quercetin-3-rhamnosylglucoside (Q-GRh), quercetin-3-glucoside (Q-G), kaempferol-3-rhamnosylglucoside (K-GRh) and kaempferol-3-galactoside (K-Ga). The present method is accurate, convenient for the rapid identification of flavonol glycosides and analysis of constituent distribution for green and black teas.

  8. Flavonol-induced changes in PIN2 polarity and auxin transport in the Arabidopsis thaliana rol1-2 mutant require phosphatase activity

    Science.gov (United States)

    Kuhn, Benjamin M.; Nodzyński, Tomasz; Errafi, Sanae; Bucher, Rahel; Gupta, Shibu; Aryal, Bibek; Dobrev, Petre; Bigler, Laurent; Geisler, Markus; Zažímalová, Eva; Friml, Jiří; Ringli, Christoph

    2017-01-01

    The phytohormone auxin is a major determinant and regulatory component important for plant development. Auxin transport between cells is mediated by a complex system of transporters such as AUX1/LAX, PIN, and ABCB proteins, and their localization and activity is thought to be influenced by phosphatases and kinases. Flavonols have been shown to alter auxin transport activity and changes in flavonol accumulation in the Arabidopsis thaliana rol1-2 mutant cause defects in auxin transport and seedling development. A new mutation in ROOTS CURL IN NPA 1 (RCN1), encoding a regulatory subunit of the phosphatase PP2A, was found to suppress the growth defects of rol1-2 without changing the flavonol content. rol1-2 rcn1-3 double mutants show wild type-like auxin transport activity while levels of free auxin are not affected by rcn1-3. In the rol1-2 mutant, PIN2 shows a flavonol-induced basal-to-apical shift in polar localization which is reversed in the rol1-2 rcn1-3 to basal localization. In vivo analysis of PINOID action, a kinase known to influence PIN protein localization in a PP2A-antagonistic manner, revealed a negative impact of flavonols on PINOID activity. Together, these data suggest that flavonols affect auxin transport by modifying the antagonistic kinase/phosphatase equilibrium. PMID:28165500

  9. High-flavonol tomatoes resulting from the heterologous expression of the maize transcription factor genes LC and C1.

    Science.gov (United States)

    Bovy, Arnaud; de Vos, Ric; Kemper, Mark; Schijlen, Elio; Almenar Pertejo, Maria; Muir, Shelagh; Collins, Geoff; Robinson, Sue; Verhoeyen, Martine; Hughes, Steve; Santos-Buelga, Celestino; van Tunen, Arjen

    2002-10-01

    Flavonoids are a group of polyphenolic plant secondary metabolites important for plant biology and human nutrition. In particular flavonols are potent antioxidants, and their dietary intake is correlated with a reduced risk of cardiovascular diseases. Tomato fruit contain only in their peel small amounts of flavonoids, mainly naringenin chalcone and the flavonol rutin, a quercetin glycoside. To increase flavonoid levels in tomato, we expressed the maize transcription factor genes LC and C1 in the fruit of genetically modified tomato plants. Expression of both genes was required and sufficient to upregulate the flavonoid pathway in tomato fruit flesh, a tissue that normally does not produce any flavonoids. These fruit accumulated high levels of the flavonol kaempferol and, to a lesser extent, the flavanone naringenin in their flesh. All flavonoids detected were present as glycosides. Anthocyanins, previously reported to accumulate upon LC expression in several plant species, were present in LC/C1 tomato leaves but could not be detected in ripe LC/C1 fruit. RNA expression analysis of ripening fruit revealed that, with the exception of chalcone isomerase, all of the structural genes required for the production of kaempferol-type flavonols and pelargonidin-type anthocyanins were induced strongly by the LC/C1 transcription factors. Expression of the genes encoding flavanone-3'-hydroxylase and flavanone-3'5'-hydroxylase, which are required for the modification of B-ring hydroxylation patterns, was not affected by LC/C1. Comparison of flavonoid profiles and gene expression data between tomato leaves and fruit indicates that the absence of anthocyanins in LC/C1 fruit is attributable primarily to an insufficient expression of the gene encoding flavanone-3'5'-hydroxylase, in combination with a strong preference of the tomato dihydroflavonol reductase enzyme to use the flavanone-3'5'-hydroxylase reaction product dihydromyricetin as a substrate.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Physico-chemical and Biological Evaluation of Flavonols: Fisetin, Quercetin and Kaempferol Alone and Incorporated in beta Cyclodextrins.

    Science.gov (United States)

    Corina, Danciu; Bojin, Florina; Ambrus, Rita; Muntean, Delia; Soica, Codruta; Paunescu, Virgil; Cristea, Mirabela; Pinzaru, Iulia; Dehelean, Cristina

    2017-01-01

    Fisetin,quercetin and kaempferol are among the important representatives of flavonols, biological active phytocomounds, with low water solubility. To evaluate the antimicrobial effect, respectively the antiproliferative and pro apoptotic activity on the B164A5 murine melanoma cell line of pure flavonols and their beta cyclodextrins complexes. Incorporation of fisetin, quercetin and kaempferol in beta cyclodextrins was proved by scanning electron microscopy (SEM), differencial scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Pure compounds and their complexes were tested for antiproliferative (MTT) and pro-apoptotic activity (Annexin V-PI) on the B164A5 murine melanoma cell line and for the antimicrobial properties (Disk Diffusion Method) on the selected strains. The phytocompounds presented in a different manner in vitro chemopreventive activity against B164A5 murine melanoma cell line and weak antimicrobial effect. The three flavonols: fisetin, quercetin and kaempferol were successfully incorporated in beta-cyclodextrin (BCD) and hydroxylpropyl-beta-cyclodextrin (HPBCD). Incorporation in beta cyclodextrins had a mix effect on the biological activity conducing to decrease, increase or consistent effect compared to pure phytocompound, depending on the screened process and on the chosen combination. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  12. Influence of light and temperature on gene expression leading to accumulation of specific flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica

    Directory of Open Access Journals (Sweden)

    Susanne eNeugart

    2016-03-01

    Full Text Available Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 µmol m-2 s-1 or 100 µmol m-2 s-1 at 10°C, or at 400 µmol m-2 s-1 with 5°C or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5°C or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides

  13. Influence of Light and Temperature on Gene Expression Leading to Accumulation of Specific Flavonol Glycosides and Hydroxycinnamic Acid Derivatives in Kale (Brassica oleracea var. sabellica).

    Science.gov (United States)

    Neugart, Susanne; Krumbein, Angelika; Zrenner, Rita

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plants were grown either at 400 μmol m(-2) s(-1) or 100 μmol m(-2) s(-1) at 10°C, or at 400 μmol m(-2) s(-1) with 5 or 15°C. The higher light intensity overall increased flavonol content of leaves, favoring the main quercetin glycosides, a caffeic acid monoacylated kaempferol triglycoside, and disinapoyl-gentiobiose. The higher temperature mainly increased the hydroxycinnamic acid derivative disinapoyl-gentiobiose, while at lower temperature synthesis is in favor of very complex sinapic acid acylated flavonol tetraglycosides such as kaempferol-3-O-sinapoyl-sophoroside-7-O-diglucoside. A global analysis of light and temperature dependent alterations of gene expression in B. oleracea var. sabellica leaves was performed with the most comprehensive Brassica microarray. When compared to the light experiment much less genes were differentially expressed in kale leaves grown at 5 or 15°C. A structured evaluation of differentially expressed genes revealed the expected enrichment in the functional categories of e.g. protein degradation at different light intensities or phytohormone metabolism at different temperature. Genes of the secondary metabolism namely phenylpropanoids are significantly enriched with both treatments. Thus, the genome of B. oleracea was screened for predicted genes putatively involved in the biosynthesis of flavonoids and hydroxycinnamic acid derivatives. All identified B. oleracea genes were analyzed for their most specific 60-mer oligonucleotides present on the

  14. Flavonol Glycosides in Currant Leaves and Variation with Growth Season, Growth Location, and Leaf Position.

    Science.gov (United States)

    Yang, Wei; Alanne, Aino-Liisa; Liu, Pengzhan; Kallio, Heikki; Yang, Baoru

    2015-10-28

    Flavonol glycosides (FG) were analyzed in the leaves of six currant cultivars (Ribes spp.) with HPLC-DAD, HPLC-MS/MS, and NMR. The average amounts of the 12 major, identified FG constituted 86-93% (9.6-14.1 mg/g DW) of the total of 27 FG found. Quercetin and kaempferol were the major aglycones with trace amounts of myricetin. Quercetin-3-O-(2,6-α-dirhamnopyranosyl-β-glucopyranoside), quercetin-3-O-(2-β-xylopyranosyl-6-α-rhamnopyranosyl-β-glucopyranoside), and kaempferol-3-O-(3,6-α-dirhamnopyranosyl-β-glucopyranoside) were identified for the first time in currant leaves and existed in a white currant cultivar 'White Dutch' only. Kaempferol-3-O-β-(6'-malonyl)glucopyranoside was also a new compound existing in abundance in five cultivars but not in the white one. The results show the primary importance of the genetic background of the cultivars. The content of malonylated FG of special importance in cardiovascular health decreased regularly during summer. Time of collection and leaf position were more prominent factors affecting the composition than were the year of harvest or the growth latitude. Randomly collected leaves differed in their FG profiles from those collected from the middle position of new branches.

  15. Application of Differential Colorimetry To Evaluate Anthocyanin-Flavonol-Flavanol Ternary Copigmentation Interactions in Model Solutions.

    Science.gov (United States)

    Gordillo, Belén; Rodríguez-Pulido, Francisco J; González-Miret, M Lourdes; Quijada-Morín, Natalia; Rivas-Gonzalo, Julián C; García-Estévez, Ignacio; Heredia, Francisco J; Escribano-Bailón, M Teresa

    2015-09-09

    The combined effect of anthocyanin-flavanol-flavonol ternary interactions on the colorimetric and chemical stability of malvidin-3-glucoside has been studied. Model solutions with fixed malvidin-3-glucoside/(+)-catechin ratio (MC) and variable quercetin-3-β-d-glucoside concentration (MC+Q) and solutions with fixed malvidin-3-glucoside/quercetin-3-β-d-glucoside ratio (MQ) and variable (+)-catechin concentration (MQ+C) were tested at levels closer to those existing in wines. Color variations during storage were evaluated by differential colorimetry. Changes in the anthocyanin concentration were monitored by HPLC-DAD. CIELAB color-difference formulas were demonstrated to be of practical interest to assess the stronger and more stable interaction of quercetin-3-β-d-glucoside with MC binary mixture than (+)-catechin with MQ mixture. The results imply that MC+Q ternary solutions kept their intensity and bluish tonalities for a longer time in comparison to MQ+C solutions. The stability of malvidin-3-glucoside improves when the concentration of quercetin-3-β-d-glucoside increases in MC+Q mixtures, whereas the addition of (+)-catechin in MQ+C mixtures resulted in an opposite effect.

  16. Detoxification of polycyclic aromatic hydrocarbons (PAHs) in Arabidopsis thaliana involves a putative flavonol synthase.

    Science.gov (United States)

    Hernández-Vega, Juan C; Cady, Brian; Kayanja, Gilbert; Mauriello, Anthony; Cervantes, Natalie; Gillespie, Andrea; Lavia, Lisa; Trujillo, Joshua; Alkio, Merianne; Colón-Carmona, Adán

    2017-01-05

    Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants with cytotoxic, teratogenic and carcinogenic properties. Bioremediation studies with bacteria have led to the identification of dioxygenases (DOXs) in the first step to degrade these recalcitrant compounds. In this study, we characterized the role of the Arabidopsis thaliana AT5G05600, a putative DOX of the flavonol synthase family, in the transformation of PAHs. Phenotypic analysis of loss-of-function mutant lines showed that these plant lines were less sensitive to the toxic effects of phenanthrene, suggesting possible roles of this gene in PAH degradation in vivo. Interestingly, these mutant lines showed less accumulation of H2O2 after PAH exposure. Transgenic lines over-expressing At5g05600 showed a hypersensitive response and more oxidative stress after phenanthrene treatments. Moreover, fluorescence spectra results of biochemical assays with the recombinant His-tagged protein AT5G05600 detected chemical modifications of phenanthrene. Taken together, these results support the hypothesis that AT5G05600 is involved in the catabolism of PAHs and the accumulation of toxic intermediates during PAH biotransformation in plants. This research represents the first step in the design of transgenic plants with the potential to degrade PAHs, leading to the development of vigorous plant varieties that can reduce the levels of these pollutants in the environment. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Crystal structure of a human cyclin-dependent kinase 6 complexwith a flavonol inhibitor, Fisetin

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Heshu; Chang, Debbie J.; Baratte, Blandine; Meijer, Laurent; Schulze-Gahmen, Ursula

    2005-01-10

    Cyclin-dependent kinases (CDKs) play a central role in cell cycle control, apoptosis, transcription and neuronal functions. They are important targets for the design of drugs with anti-mitotic and/or anti-neurodegenerative effects. CDK4 and CDK6 form a subfamily among the CDKs in mammalian cells, as defined by sequence similarities. Compared to CDK2 and CDK5, structural information on CDK4 and CDK6 is sparse. We describe here the crystal structure of human CDK6 in complex with a viral cyclin and a flavonol inhibitor, fisetin. Fisetin binds to the active form of CDK6, forming hydrogen bonds with the side chains of residues in the binding pocket that undergo large conformational changes during CDK activation by cyclin binding. The 4-keto group and the 3-hydroxyl group of fisetin are hydrogen bonded with the backbone in the hinge region between the N-terminal and C-terminal kinase domain, as has been observed for many CDK inhibitors. However, CDK2 and HCK kinase in complex with other flavone inhibitors such as quercetin and flavopiridol showed a different binding mode with the inhibitor rotated by about 180. The structural information of the CDK6-fisetin complex is correlated with the binding affinities of different flavone inhibitors for CDK6. This complex structure is the first description of an inhibitor complex with a kinase from the CDK4/6 subfamily and can provide a basis for selecting and designing inhibitor compounds with higher affinity and specificity.

  18. Identification and quantification of glucosinolate and flavonol compounds in rocket salad (Eruca sativa, Eruca vesicaria and Diplotaxis tenuifolia) by LC–MS: Highlighting the potential for improving nutritional value of rocket crops

    OpenAIRE

    Bell, Luke; Oruna-Concha, Maria Jose; Wagstaff, Carol

    2015-01-01

    Liquid Chromatography Mass Spectrometry (LC-MS) was used to obtain glucosinolate and flavonol content for 35 rocket accessions and commercial varieties. 13 glucosinolates and 11 flavonol compounds were identified. Semi-quantitative methods were used to estimate concentrations of both groups of compounds. Minor glucosinolate composition was found to be different between accessions; concentrations varied significantly. Flavonols showed differentiation between genera, with Diplotaxis accumulatin...

  19. Antioxidant Activities of Extract and Fractions from Receptaculum Nelumbinis and Related Flavonol Glycosides

    Directory of Open Access Journals (Sweden)

    Jun Yi

    2012-06-01

    Full Text Available The antioxidant activities of ethanolic crude extract (ECE and its four different solvent sub-fractions (namely, petroleum ether fraction (PEF, ethyl acetate fraction (EAF, n-butanol fraction (BF and the aqueous fraction (AF from the receptacles of Nelumbo nucifera Gaertn. (Receptaculum Nelumbinis were investigated using two in vitro antioxidant assays. BF showed the highest total phenolic content (607.6 mg/g gallic acid equivalents, total flavonoid content (862.7 mg/g rutin equivalents and total proanthocyanidin content (331.0 mg/g catechin equivalents, accompanied with the highest antioxidant activity compared to other fractions through 1,1-diphenyl-2-picrylhydrazyl (DPPH and 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid (ABTS radical scavenging assays. Five flavonol glycosides, namely hyperoside (1, isoquercitrin (2, quercetin-3-O-β-D-glucuronide (3, isorhamnetin-3-O-β-D-galactoside (4 and syringetin-3-O-β-D-glucoside (5 were isolated from the Receptaculum Nelumbinis. Compounds 25 were isolated for the first time from the Receptaculum Nelumbinis. The five isolated flavone glycosides, particularly compounds 13, demonstrated significant DPPH and ABTS radical scavenging activity, with IC50 values of 8.9 ± 0.2, 5.2 ± 0.2, 7.5 ± 0.1 for DPPH and 114.2 ± 1.7, 112.8 ± 0.8, 172.5 ± 0.7 µg/mL for ABTS, respectively. These results suggest that Receptaculum Nelumbinis has strong antioxidant potential and may be potentially used as a safe and inexpensive bioactive source of natural antioxidants.

  20. Functional Differentiation of the Glycosyltransferases That Contribute to the Chemical Diversity of Bioactive Flavonol Glycosides in Grapevines (Vitis vinifera)[W][OA

    Science.gov (United States)

    Ono, Eiichiro; Homma, Yu; Horikawa, Manabu; Kunikane-Doi, Satoshi; Imai, Haruna; Takahashi, Seiji; Kawai, Yosuke; Ishiguro, Masaji; Fukui, Yuko; Nakayama, Toru

    2010-01-01

    We identified two glycosyltransferases that contribute to the structural diversification of flavonol glycosides in grapevine (Vitis vinifera): glycosyltransferase 5 (Vv GT5) and Vv GT6. Biochemical analyses showed that Vv GT5 is a UDP-glucuronic acid:flavonol-3-O-glucuronosyltransferase (GAT), and Vv GT6 is a bifunctional UDP-glucose/UDP-galactose:flavonol-3-O-glucosyltransferase/galactosyltransferase. The Vv GT5 and Vv GT6 genes have very high sequence similarity (91%) and are located in tandem on chromosome 11, suggesting that one of these genes arose from the other by gene duplication. Both of these enzymes were expressed in accordance with flavonol synthase gene expression and flavonoid distribution patterns in this plant, corroborating their significance in flavonol glycoside biosynthesis. The determinant of the specificity of Vv GT5 for UDP-glucuronic acid was found to be Arg-140, which corresponded to none of the determinants previously identified for other plant GATs in primary structures, providing another example of convergent evolution of plant GAT. We also analyzed the determinants of the sugar donor specificity of Vv GT6. Gln-373 and Pro-19 were found to play important roles in the bifunctional specificity of the enzyme. The results presented here suggest that the sugar donor specificities of these Vv GTs could be determined by a limited number of amino acid substitutions in the primary structures of protein duplicates, illustrating the plasticity of plant glycosyltransferases in acquiring new sugar donor specificities. PMID:20693356

  1. Flavonol-enriched fraction from Vaccinium macrocarpon fruit inhibits matrix metalloproteinase-2, matrix metalloproteinase-9 and urokinase-type plasminogen activator expression in human prostate cancer cells in vitro

    Directory of Open Access Journals (Sweden)

    James MacPhee

    2014-11-01

    Full Text Available Background: Prostate cancer, amongst other cancer types has a genetic and environmental component, which can contribute to prostate cancer development and progression. Vaccinum macrocarpon (American cranberry is a botanical that contains several phytochemicals which have been suggested to play a role in preventing cardiovascular disease, cancer, and urinary tract infections as well as in the maintenance of oral health. Context and purpose of this study: This investigation evaluated the effects of a flavonolenriched fraction (FL from the American cranberry (Vaccinium macrocarpon containing quercetin and myricetin glycosides on matrix metalloproteinase (MMP and urokinase-type plasminogen activator (uPA activities and their associated regulatory proteins in DU145 human prostate cancer cells in vitro. Results: A flavonol-enriched fraction (FL was prepared from Vaccinium macrocarpon berries and the effect of this fraction on prostate cancer cell behaviour was assessed using biochemical and molecular approaches including cytotoxicity assays and Western blot analysis to determine protein expression. Cranberry FL decreased cellular viability of DU145 cells at a concentration of 25 ug/ml by 20% after 6 hours of treatment. Further investigations determined that associated with this cytotoxicity, cranberry FL decreases matrix metalloproteinase (MMP ( specifically MMP-2 and MMP-9 activity and urokinase plasminogen activator (uPA activity through effects on specific temporal MMP regulators and uPA regulators and by affecting either the phosphorylation status and/or expression of specific MAP kinase, PI-3 kinase, NF-kB and AP-1 pathway associated proteins. Conclusion: This study demonstrates, for the first time, the ability of Vaccinium macrocarpon flavonols to modulate cellular pathways associated with migration, invasion, and proliferation, suggesting that cranberry (Vaccinium macrocarpon is a viable candidate for further research as a natural product that

  2. Hepatoprotective effect of flavonol glycosides rich fraction from Egyptian Vicia calcarata Desf. against CCl4-induced liver damage in rats.

    Science.gov (United States)

    Singab, Abdel Nasser B; Youssef, Diaa T A; Noaman, Eman; Kotb, Saeed

    2005-07-01

    The hepatoprotective activity of flavonol glycosides rich fraction (F-2), prepared from 70% alcohol extract of the aerial parts of V. calcarata Desf., was evaluated in a rat model with a liver injury induced by daily oral administration of CCl4 (100 mg/kg, b.w) for four weeks. Treatment of the animals with F-2 using a dose of (25 mg/kg, b.w) during the induction of hepatic damage by CCl4 significantly reduced the indices of liver injuries. The hepatoprotective effects of F-2 significantly reduced the elevated levels of the following serum enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). The antioxidant activity of F-2 markedly ameliorated the antioxidant parameters including glutathione (GSH) content, glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), plasma catalase (CAT) and packed erythrocytes glucose-6-phosphate dehydrogenase (G6PDH) to be comparable with normal control levels. In addition, it normalized liver malondialdehyde (MDA) levels and creatinine concentration. Chromatographic purification of F-2 resulted in the isolation of two flavonol glycosides that rarely occur in the plant kingdom, identified as quercetin-3, 5-di-O-beta-D-diglucoside (5) and kaempferol-3, 5-di-O-beta-D-diglucoside (4) in addition to the three known compounds identified as quercetin-3-O-alpha-L-rhamnosyl- (1-->6)-beta-D-glucoside [rutin, 3], quercetin-3-O-beta-D-glucoside [isoquercitrin, 2] and kaempferol-3-O-beta-D-glucoside [astragalin, 1]. These compounds were identified based on interpretation of their physical, chemical, and spectral data. Moreover, the spectrophotometric estimation of the flavonoids content revealed that the aerial parts of the plant contain an appreciable amount of flavonoids (0.89%) calculated as rutin. The data obtained from this study revealed that the flavonol glycosides of F-2 protect the rat liver from hepatic damage induced by CCl4 through inhibition of

  3. Negative Regulation of Anthocynanin Biosynthesis in Arabidopsis by a miR156-Targeted SPL Transcription Factor

    Energy Technology Data Exchange (ETDEWEB)

    Gou, J.Y.; Liu, C.; Felippes, F. F.; Weigel, D.; Wang, J.-W.

    2011-04-01

    Flavonoids are synthesized through an important metabolic pathway that leads to the production of diverse secondary metabolites, including anthocyanins, flavonols, flavones, and proanthocyanidins. Anthocyanins and flavonols are derived from Phe and share common precursors, dihydroflavonols, which are substrates for both flavonol synthase and dihydroflavonol 4-reductase. In the stems of Arabidopsis thaliana, anthocyanins accumulate in an acropetal manner, with the highest level at the junction between rosette and stem. We show here that this accumulation pattern is under the regulation of miR156-targeted SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL) genes, which are deeply conserved and known to have important roles in regulating phase change and flowering. Increased miR156 activity promotes accumulation of anthocyanins, whereas reduced miR156 activity results in high levels of flavonols. We further provide evidence that at least one of the miR156 targets, SPL9, negatively regulates anthocyanin accumulation by directly preventing expression of anthocyanin biosynthetic genes through destabilization of a MYB-bHLH-WD40 transcriptional activation complex. Our results reveal a direct link between the transition to flowering and secondary metabolism and provide a potential target for manipulation of anthocyanin and flavonol content in plants.

  4. Impact of Flavonols on Cardiometabolic Biomarkers: A Meta-Analysis of Randomized Controlled Human Trials to Explore the Role of Inter-Individual Variability

    Science.gov (United States)

    Menezes, Regina; Rodriguez-Mateos, Ana; Kaltsatou, Antonia; González-Sarrías, Antonio; Greyling, Arno; Giannaki, Christoforos; Andres-Lacueva, Cristina; Milenkovic, Dragan; Gibney, Eileen R.; Dumont, Julie; Schär, Manuel; Garcia-Aloy, Mar; Palma-Duran, Susana Alejandra; Ruskovska, Tatjana; Maksimova, Viktorija; Combet, Emilie; Pinto, Paula

    2017-01-01

    Several epidemiological studies have linked flavonols with decreased risk of cardiovascular disease (CVD). However, some heterogeneity in the individual physiological responses to the consumption of these compounds has been identified. This meta-analysis aimed to study the effect of flavonol supplementation on biomarkers of CVD risk such as, blood lipids, blood pressure and plasma glucose, as well as factors affecting their inter-individual variability. Data from 18 human randomized controlled trials were pooled and the effect was estimated using fixed or random effects meta-analysis model and reported as difference in means (DM). Variability in the response of blood lipids to supplementation with flavonols was assessed by stratifying various population subgroups: age, sex, country, and health status. Results showed significant reductions in total cholesterol (DM = −0.10 mmol/L; 95% CI: −0.20, −0.01), LDL cholesterol (DM = −0.14 mmol/L; 95% CI: −0.21, 0.07), and triacylglycerol (DM = −0.10 mmol/L; 95% CI: −0.18, 0.03), and a significant increase in HDL cholesterol (DM = 0.05 mmol/L; 95% CI: 0.02, 0.07). A significant reduction was also observed in fasting plasma glucose (DM = −0.18 mmol/L; 95% CI: −0.29, −0.08), and in blood pressure (SBP: DM = −4.84 mmHg; 95% CI: −5.64, −4.04; DBP: DM = −3.32 mmHg; 95% CI: −4.09, −2.55). Subgroup analysis showed a more pronounced effect of flavonol intake in participants from Asian countries and in participants with diagnosed disease or dyslipidemia, compared to healthy and normal baseline values. In conclusion, flavonol consumption improved biomarkers of CVD risk, however, country of origin and health status may influence the effect of flavonol intake on blood lipid levels. PMID:28208791

  5. Antioxidant and free radical scavenging activity of flavonol glycosides from different Aconitum species.

    Science.gov (United States)

    Braca, Alessandra; Fico, Gelsomina; Morelli, Ivano; De Simone, Francesco; Tomè, Franca; De Tommasi, Nunziatina

    2003-05-01

    Bioassay-guided fractionation by 1,1-diphenyl-2-dipicrylhydrazyl (DPPH) radical scavenging test of polar extracts of some Italian Aconitum species (A. napellus subsp. tauricum, A. napellus subsp. neomontanum, A. paniculatum, A. vulparia) led to the isolation of 13 flavonol glycosides: quercetin 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (1), kaempferol 3-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (2), quercetin 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (3), kaempferol 3-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->2)-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (4), quercetin 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (5), kaempferol 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (6), kaempferol 7-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (7), kaempferol 3-O-beta-(2"-acetyl)galactopyranoside (8), kaempferol 3-O-beta-(2"-acetyl)galactopyranoside-7-O-alpha-arabinopyranoside (9), quercetin 3-O-beta-(2"-acetyl)galactopyranoside-7-O-alpha-arabinopyranoside (10), quercetin 3,7-di-O-alpha-rhamnopyranoside (11), kaempferol 3,7-di-O-alpha-rhamnopyranoside (12) and quercetin 3-O-beta-glucopyranoside-7-O-alpha-rhamnopyranoside (13). Their antioxidant activity (AA) was determined by measuring free radical scavenging activity by DPPH test and the coupled oxidation of beta-carotene and linoleic acid assay. The results showed that 5 is the most active compound in the DPPH free-radical scavenging test (IC(50) 1.9 microM) while in the coupled oxidation of beta-carotene and linoleic acid assay compound 1 has the highest inhibitory ratio after 1h (58.9%). Some structure-activity relationships on the AA were obtained.

  6. Analysis of flavonol glycoside isomers from leaves of Maytenus ilicifolia by offline and online high performance liquid chromatography-electrospray mass spectrometry.

    Science.gov (United States)

    de Souza, Lauro M; Cipriani, Thales R; Serrato, Rodrigo V; da Costa, Denise E; Iacomini, Marcello; Gorin, Philip A J; Sassaki, Guilherme L

    2008-10-17

    Flavonol glycosides present in leaves of Maytenus ilicifolia, were examined after fractionation on silica-gel column. Flavonol mono-, di-, tri-, and tetraglycosides, containing kaempferol, quercetin or myricetin were identified by offline electrospray mass spectrometry. Increasing the cone energy induced to adducts variation, from H(+) to Na(+). Protonated ions were characteristically fragmented by sequentially removing the monosaccharide residues, whereas in the sodiated ions, the aglycone was firstly removed. Online high performance liquid chromatography-mass spectrometry, with simple gradients of water, acetonitrile and acetic acid indicated the presence of several isomers, which were further identified by gas chromatography-mass spectrometry as containing galactose or glucose.

  7. Flavonol content and biometrical traits as a tool for the characterization of "Cipolla di Giarratana": a traditional Sicilian onion landrace.

    Science.gov (United States)

    Riggi, Ezio; Avola, Giovanni; Siracusa, Laura; Ruberto, Giuseppe

    2013-10-15

    "Cipolla di Giarratana", a locally cultivated white onion landrace, is listed as an item in the 'List of Traditional Agro-food Products' of the Italian Department for Agriculture and itemised as 'slow food presidium' by the Slow Food Foundation. Ten local accessions were investigated for their biomorphological and biochemical characteristics in five experimental locations. High-performance liquid chromatography coupled with diode array detection and electron spray-mass spectrometry (HPLC/DAD/ESI-MS) was used to identify the phenolic profile and quantify phenolic content in bulbs: quercetin, quercetin 3,4' di-O-glucoside and quercetin 4'-O-glucoside were detected as major components. The 'Cipolla di Giarratana' landrace is characterised by a high bulb weight (436g) and high diameter (11cm). The total flavonols content ranged between 68 and 408mgkg(-1) bulb fresh weight in nine of the 10 collected accessions. The opportunity of considering flavonol patterns as chemotaxonomic descriptors in order to characterise onion germplasm is also discussed.

  8. Flavonol Glucoside and Antioxidant Enzyme Biosynthesis Affected by Mycorrhizal Fungi in Various Cultivars of Onion (Allium cepa L.).

    Science.gov (United States)

    Mollavali, Mohanna; Bolandnazar, Saheb Ali; Schwarz, Dietmar; Rohn, Sascha; Riehle, Peer; Zaare Nahandi, Fariborz

    2016-01-13

    The objective of this study was to investigate the impact of mycorrhizal symbiosis on qualitative characteristics of onion (Allium cepa L.). For this reason, five onion cultivars with different scale color and three different strains of arbuscular mycorrhizal fungi (Diversispora versiformis, Rhizophagus intraradices, Funneliformis mosseae) were used. Red cultivars, mainly 'Red Azar-shahr', showed the highest content in vitamin C, flavonols, and antioxidant enzymes. Mycorrhizal inoculation increased total phenolic, pyruvic acid, and vitamin C of onion plants. Considerable increase was observed in quercetin-4'-O-monoglucoside and isorhamnetin-4'-O-monoglucoside content in plants inoculated with Diversispora versiformis, but quercetin-3,4'-O-diglucoside was not significantly influenced. Analyses for phenylalanine ammonia-lyase (PAL) and antioxiodant enzyme activities such as polyphenol oxidase (PPO), catalase (CAT), and peroxidase (POD) revealed that all except PPO were enhanced by mycorrhizal inoculation. Overall, these findings suggested that mycorrhizal inoculation influenced biosynthesis of flavonol glucosides and antioxidant enzymes by increasing nutrient uptake or by induction of the plant defense system.

  9. Antioxidant and antiatherogenic properties of phenolic acid and flavonol fractions of fruits of 'Amari' and 'Hallawi' date (Phoenix dactylifera L.) varieties.

    Science.gov (United States)

    Borochov-Neori, Hamutal; Judeinstein, Sylvie; Greenberg, Amnon; Volkova, Nina; Rosenblat, Mira; Aviram, Michael

    2015-04-01

    Date (Phoenix dactylifera L.) fruit phenolic-acid or flavonol fractions were examined in vitro for antioxidant and antiatherogenic properties. Two fractions of each subgroup were prepared from two date varieties, 'Amari' and 'Hallawi', by solid phase extraction on C18. The fractions were analyzed for phenolics composition by RP-HPLC and tested for ferric-reducing antioxidant power, free radical scavenging capacity, inhibition of Cu(2+)-induced LDL oxidation, and enhancement of HDL-mediated cholesterol efflux from macrophages. All four fractions exhibited variable capacities to reduce ferric ions, scavenge radicals, and inhibit LDL oxidation. Flavonol fractions were considerably better inhibitors of LDL oxidation compared to phenolic acid fractions, with IC50's of 9-31 nmol GAE mL(-1) compared to 85-116 nmol GAE mL(-1), respectively. Only the flavonol fractions stimulated cholesterol removal from macrophages. Within each subgroup, the levels of all the activities varied with fraction composition. The results demonstrated strong structure-activity relationships for date phenolics and identified date flavonols as potential antiatherogenic bioactives.

  10. Quantitative analysis of flavonols, flavones, and flavanones in fruits, vegetables and beverages by high-performance liquid chromatography with photo-diode array and mass spectrometric detection

    DEFF Research Database (Denmark)

    Justesen, U.; Knuthsen, Pia; Leth, Torben

    1998-01-01

    A high-performance liquid chromatographic (HPLC) separation method viith photo-diode array (PDA) and mass spectrometric (MS) detection was developed to determine and quantify flavonols, flavones, and flavanones in fruits, vegetables and beverages. The compounds were analysed as aglycones, obtained...

  11. Genetic resources of the functional food, teramnus labialis (L.f.) spreng for improving seed number, flavonol content, oil %, and fatty acid compositions

    Science.gov (United States)

    Teramnus labialis is used as food in India and has potential to be used as a functional food vegetable in the U.S.A. Photoperiod-sensitive T. labialis accessions were grown in the greenhouse from 2010 to 2011 and evaluated for flavonol content, oil %, and fatty acid compositions. Significant variati...

  12. Determination of Ginkgolides and Flavonols in Ginkgo Biloba Products and NIST Ginkgo Reference Standard by LC/UV/MS (Experimental Biology, April, 2007, Washington, D.C.)

    Science.gov (United States)

    The leaf extract of Ginkgo biloba has purported value for improving mental capacities in Alzheimer’s patients. The flavonols and the terpene lactones are considered to be the two main active components that influence human health. Almost all the clinical studies regarding Ginkgo biloba used either...

  13. UHPLC/PDA–ESI/MS Analysis of the Main Berry and Leaf Flavonol Glycosides from Different Carpathian Hippophaë rhamnoides L. Varieties

    NARCIS (Netherlands)

    Pop, R.M.; Socaciu, C.; Pintea, A.; Buzoianu, A.D.; Sanders, M.G.; Gruppen, H.; Vincken, J.P.

    2013-01-01

    Introduction - Sea buckthorn (Hippophaë rhamnoides L.) is known to be rich in many bioactive compounds (such as vitamins, phenolics, carotenoids) important for human health and nutrition. Among the phenolics, berries and leaves contain a wide range of flavonols that are good quality and authenticity

  14. Ultra performance liquid chromatography-tandem quadrupole mass spectrometry profiling of anthocyanins and flavonols in cowpea (Vigna unguiculata) of varying genotypes.

    Science.gov (United States)

    Ojwang, Leonnard O; Dykes, Linda; Awika, Joseph M

    2012-04-11

    The structure of flavonoids in food plants affects bioactivity and important nutritional attributes, like micronutrient bioavailability. This study investigated flavonol and anthocyanin compositions of cowpea (Vigna unguiculata) of varying genotypes. Black, red, green, white, light brown, and golden brown cowpea phenotypes were analyzed for anthocyanins and flavonols using ultra performance liquid chromatography-tandem quadrupole mass spectrometry. Eight anthocyanins and 23 flavonols (15 newly identified in cowpea) were characterized. Mono-, di-, and tri(acyl)glycosides of quercetin were predominant in most phenotypes; myricetin and kaempferol glycosides were present only in specific phenotypes. The red phenotypes had the highest flavonol content (880-1060 μg/g), whereas green and white phenotypes had the lowest (270-350 μg/g). Only black (1676-2094 μg/g) and green (875 μg/g) phenotypes had anthocyanins, predominantly delphinidin and cyanidin 3-O-glucosides. Cowpea phenotype influenced the type and amount of flavonoids accumulated in the seed; this may have implications in selecting varieties for nutrition and health applications.

  15. Priming of seeds with methyl jasmonate induced resistance to hemi-biotroph Fusarium oxysporum f.sp. lycopersici in tomato via 12-oxo-phytodienoic acid, salicylic acid, and flavonol accumulation.

    Science.gov (United States)

    Król, P; Igielski, R; Pollmann, S; Kępczyńska, E

    2015-05-01

    Methyl jasmonate (MeJA) was tested by seed treatment for its ability to protect tomato seedlings against fusarium wilt caused by the soil-borne fungal pathogen Fusarium oxysporum f.sp. lycopersici. Isolated from Solanum lycopersicon L. seeds, cv. Beta fungus was identified as F. oxysporum f.sp. lycopersici Race 3 fungus by using phytopathological and molecular methods. MeJA applied at 0.01, 0.1 and 1 mM reduced spore germination and mycelial growth in vitro. Soaking of tomato seeds in MeJA solution at 0.1 mM for 1 h significantly enhanced the resistance level against the tested fungus in tomato seedlings 4 weeks after inoculation. The extracts from leaves of 15-day-old seedlings obtained from previously MeJA soaked seeds had the ability to inhibit in vitro spore germination of tested fungus. In these seedlings a significant increase in the levels phenolic compounds such as salicylic acid (SA), kaempferol and quercetin was observed. Up-regulation of phenylalanine ammonia-lyase (PAL5) and benzoic acid/salicylic acid carboxyl methyltransferase (BSMT) genes and down-regulation of the isochorysmate synthase (ICS) gene in response to exogenous MeJA application indicate that the phenylalanine ammonia-lyase (PAL), not the isochorismate (IC) pathway, is the primary route for SA production in tomato. Moreover, the increased accumulation of the flavonols quercetin and kaempferol appears closely related to the increase of PAL5, chalcone synthase (CHS) and flavonol synthase/flavanone 3-hydroxylase-like (FLS) genes. Elevated levels of salicylic acid in seedlings raised from MeJA-soaked seeds were simultaneously accompanied by a decrease of jasmonic acid, the precursor of MeJA, and an increase of 12-oxo-phytodienoic acid (OPDA), the precursor of jasmonic acid. The present results indicate that the priming of tomato seeds with 0.1mM MeJA before sowing enables the seedlings grown from these seeds to reduce the attack of the soil-borne fungal pathogen F. oxysporum f.sp. lycopersici

  16. Identification and quantification of glucosinolate and flavonol compounds in rocket salad (Eruca sativa, Eruca vesicaria and Diplotaxis tenuifolia) by LC-MS: highlighting the potential for improving nutritional value of rocket crops.

    Science.gov (United States)

    Bell, Luke; Oruna-Concha, Maria Jose; Wagstaff, Carol

    2015-04-01

    Liquid chromatography mass spectrometry (LC-MS) was used to obtain glucosinolate and flavonol content for 35 rocket accessions and commercial varieties. 13 glucosinolates and 11 flavonol compounds were identified. Semi-quantitative methods were used to estimate concentrations of both groups of compounds. Minor glucosinolate composition was found to be different between accessions; concentrations varied significantly. Flavonols showed differentiation between genera, with Diplotaxis accumulating quercetin glucosides and Eruca accumulating kaempferol glucosides. Several compounds were detected in each genus that have only previously been reported in the other. We highlight how knowledge of phytochemical content and concentration can be used to breed new, nutritionally superior varieties. We also demonstrate the effects of controlled environment conditions on the accumulations of glucosinolates and flavonols and explore the reasons for differences with previous studies. We stress the importance of consistent experimental design between research groups to effectively compare and contrast results.

  17. Identification and quantification of glucosinolate and flavonol compounds in rocket salad (Eruca sativa, Eruca vesicaria and Diplotaxis tenuifolia) by LC–MS: Highlighting the potential for improving nutritional value of rocket crops

    Science.gov (United States)

    Bell, Luke; Oruna-Concha, Maria Jose; Wagstaff, Carol

    2015-01-01

    Liquid chromatography mass spectrometry (LC–MS) was used to obtain glucosinolate and flavonol content for 35 rocket accessions and commercial varieties. 13 glucosinolates and 11 flavonol compounds were identified. Semi-quantitative methods were used to estimate concentrations of both groups of compounds. Minor glucosinolate composition was found to be different between accessions; concentrations varied significantly. Flavonols showed differentiation between genera, with Diplotaxis accumulating quercetin glucosides and Eruca accumulating kaempferol glucosides. Several compounds were detected in each genus that have only previously been reported in the other. We highlight how knowledge of phytochemical content and concentration can be used to breed new, nutritionally superior varieties. We also demonstrate the effects of controlled environment conditions on the accumulations of glucosinolates and flavonols and explore the reasons for differences with previous studies. We stress the importance of consistent experimental design between research groups to effectively compare and contrast results. PMID:25442630

  18. Antimicrobial and selected in vitro enzyme inhibitory effects of leaf extracts, flavonols and indole alkaloids isolated from Croton menyharthii.

    Science.gov (United States)

    Aderogba, Mutalib A; Ndhlala, Ashwell R; Rengasamy, Kannan R R; Van Staden, Johannes

    2013-10-11

    Croton species are used in folk medicine in the management of infections, inflammation and oxidative stress-related diseases. In order to isolate, characterize and evaluate the bioactive constituents of Croton menyharthii Pax leaf extracts, repeated column fractionation of the ethyl acetate fraction from a 20% aqueous methanol crude extract afforded three flavonols identified by NMR (1D and 2D) spectroscopic methods as myricetrin-3-O-rhamnoside (myricetrin, 1), quercetin-3-O-rhamnoside (2) and quercetin (3) along with an indole alkaloid, (E)-N-(4-hydroxycinnamoyl)-5-hydroxytryptamine, [trans-N-(p-coumaroyl) serotonin, 4]. All the compounds are reported from the leaf extract of this plant for the first time. The crude extracts, four solvent fractions (hexane, DCM, ethyl acetate and butanol) and isolated compounds obtained from the leaves were evaluated for their inhibitory effects on selected bacteria, a fungus (Candida albicans), cyclooxygenase (COX-2), α-glucosidase and acetylcholinesterase (AChE). Amongst the compounds, quercetin (3) was the most active against Bacillus subtilis and Candida albicans while myricetrin-3-O-rhamnoside (1) and trans-N-(p-coumaroyl) serotonin (4) were the most active compounds against Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus. The inhibitory activity of myricetrin-3-O-rhamnoside (1) against COX-2 was insignificant while that of the other three compounds 2-4 was low. The AChE inhibitory activity of the alkaloid, trans-N-(p-coumaroyl) serotonin was high, with a percentage inhibitory activity of 72.6% and an IC50 value of 15.0 µg/mL. The rest of the compounds only had moderate activity. Croton menyharthii leaf extracts and isolated compounds inhibit α-glucosidase at very low IC50 values compared to the synthetic drug acarbose. Structure activity relationship of the isolated flavonols 1-3 is briefly outlined. Compounds 1-4 and the leaf extracts exhibited a broad spectrum of activities. This validates the

  19. Antimicrobial and Selected In Vitro Enzyme Inhibitory Effects of Leaf Extracts, Flavonols and Indole Alkaloids Isolated from Croton menyharthii

    Directory of Open Access Journals (Sweden)

    Johannes Van Staden

    2013-10-01

    Full Text Available Croton species are used in folk medicine in the management of infections, inflammation and oxidative stress-related diseases. In order to isolate, characterize and evaluate the bioactive constituents of Croton menyharthii Pax leaf extracts, repeated column fractionation of the ethyl acetate fraction from a 20% aqueous methanol crude extract afforded three flavonols identified by NMR (1D and 2D spectroscopic methods as myricetrin-3-O-rhamnoside (myricetrin, 1, quercetin-3-O-rhamnoside (2 and quercetin (3 along with an indole alkaloid, (E-N-(4-hydroxycinnamoyl-5-hydroxytryptamine, [trans-N-(p-coumaroyl serotonin, 4]. All the compounds are reported from the leaf extract of this plant for the first time. The crude extracts, four solvent fractions (hexane, DCM, ethyl acetate and butanol and isolated compounds obtained from the leaves were evaluated for their inhibitory effects on selected bacteria, a fungus (Candida albicans, cyclooxygenase (COX-2, α-glucosidase and acetylcholinesterase (AChE. Amongst the compounds, quercetin (3 was the most active against Bacillus subtilis and Candida albicans while myricetrin-3-O-rhamnoside (1 and trans-N-(p-coumaroyl serotonin (4 were the most active compounds against Escherichia coli, Klebsiella pneumonia and Staphylococcus aureus. The inhibitory activity of myricetrin-3-O-rhamnoside (1 against COX-2 was insignificant while that of the other three compounds 2–4 was low. The AChE inhibitory activity of the alkaloid, trans-N-(p-coumaroyl serotonin was high, with a percentage inhibitory activity of 72.6% and an IC50 value of 15.0 µg/mL. The rest of the compounds only had moderate activity. Croton menyharthii leaf extracts and isolated compounds inhibit α-glucosidase at very low IC50 values compared to the synthetic drug acarbose. Structure activity relationship of the isolated flavonols 1–3 is briefly outlined. Compounds 1–4 and the leaf extracts exhibited a broad spectrum of activities. This validates the

  20. Evaluation of a Method to Determine Flavonol Aglycones in Ginkgo biloba Dietary Supplement Crude Materials and Finished Products by High-Performance Liquid Chromatography

    Science.gov (United States)

    Gray, Dean; LeVanseler, Kerri; Pan, Meide; Waysek, Edward H.; Baugh, S.; Chandra, A.; Meibos, R.; Peng, T.; Perez, R.; Reif, K.; Roman, M.; Rousch, J.; Skamarack, J.; Solyom, A.; Sullivan, D.; Young, K.

    2008-01-01

    An interlaboratory study was conducted for evaluation of a method to determine the flavonol aglycones quercetin, kaempferol, and isorhamnetin in Ginkgo biloba products. The method calculates total glycosides based on these aglycones formed after acid hydrolysis. Twelve matrixes were chosen for study by 12 collaborating laboratories in 2 countries. Test materials included crude leaf material, standardized dry powder extract, single and multiple entity finished products, ethanol and glycerol tinctures, and National Institute of Standards and Technology (NIST) standard reference materials (SRMs). Results from 11 laboratories were used for the final calculations. Eight of the 12 matrixes evaluated produced acceptable results for total flavonol glycosides, with HorRat scores ranging from 1.31 to 2.05; repeatability relative standard deviations (RSDr) from 1.46 to 4.14; and reproducibility relative standard deviations (RSDR) from 4.67 to 9.69. These 8 matrixes consisted primarily of simple dosage forms (e.g., dry powder extracts, crude leaf samples, liquid extracts, and SRMs) and a single tablet product (Ginkgo Awareness). Four additional matrixes, consisting of 3 tablets and 1 soft gel product (Ginkgold, Ginkoba, Ginkogen, and Ginkgo Phytosome, respectively), showed greater total flavonol glycoside HorRat scores in comparison, ranging from 2.39 to 5.13, with RSDr values from 2.83 to 8.16, and RSDR values from 8.53 to 20.4. Based on the results presented here, the method is recommended for Official First Action for determination of total flavonol glycosides calculated from quercetin, kaempferol, and isorhamnetin in dry powder extracts, crude leaf material, liquid extracts, and a select finished product, Ginkgo Awareness. PMID:17373435

  1. Effect of anthocyanins, carotenoids, and flavonols on chlorophyll fluorescence excitation spectra in apple fruit: signature analysis, assessment, modelling, and relevance to photoprotection.

    Science.gov (United States)

    Merzlyak, Mark N; Melø, Thor Bernt; Naqvi, K Razi

    2008-01-01

    Whole apple fruit (Malus domestica Borkh.) widely differing in pigment content and composition has been examined by recording its chlorophyll fluorescence excitation and diffuse reflection spectra in the visible and near UV regions. Spectral bands sensitive to the pigment concentration have been identified, and linear models for non-destructive assessment of anthocyanins, carotenoids, and flavonols via chlorophyll fluorescence measurements are put forward. The adaptation of apple fruit to high light stress involves accumulation of these protective pigments, which absorb solar radiation in broad spectral ranges extending from UV to the green and, in anthocyanin-containing cultivars, to the red regions of the spectrum. In ripening apples the protective effect in the blue region could be attributed to extrathylakoid carotenoids. A simple model, which allows the simulation of chlorophyll fluorescence excitation spectra in the visible range and a quantitative evaluation of competitive absorption by anthocyanins, carotenoids, and flavonols, is described. Evidence is presented to support the view that anthocyanins, carotenoids, and flavonols play, in fruit with low-to-moderate pigment content, the role of internal traps (insofar as they compete with chlorophylls for the absorption of incident light in specific spectral bands), affecting thereby the shape of the chlorophyll fluorescence excitation spectrum.

  2. Nondestructive Optical Sensing of Flavonols and Chlorophyll in White Head Cabbage (Brassica oleracea L. var. capitata subvar. alba) Grown under Different Nitrogen Regimens.

    Science.gov (United States)

    Agati, Giovanni; Tuccio, Lorenza; Kusznierewicz, Barbara; Chmiel, Tomasz; Bartoszek, Agnieszka; Kowalski, Artur; Grzegorzewska, Maria; Kosson, Ryszard; Kaniszewski, Stanislaw

    2016-01-13

    A multiparametric optical sensor was used to nondestructively estimate phytochemical compounds in white cabbage leaves directly in the field. An experimental site of 1980 white cabbages (Brassica oleracea L. var. capitata subvar. alba), under different nitrogen (N) treatments, was mapped by measuring leaf transmittance and chlorophyll fluorescence screening in one leaf/cabbage head. The provided indices of flavonols (FLAV) and chlorophyll (CHL) displayed the opposite response to applied N rates, decreasing and increasing, respectively. The combined nitrogen balance index (NBI = CHL/FLAV) calculated was able to discriminate all of the plots under four N regimens (0, 100, 200, and 400 kg/ha) and was correlated with the leaf N content determined destructively. CHL and FLAV were properly calibrated against chlorophyll (R(2) = 0.945) and flavonol (R(2) = 0.932) leaf contents, respectively, by using a homographic fit function. The proposed optical sensing of cabbage crops can be used to estimate the N status of plants and perform precision fertilization to maintain acceptable crop yield levels and, additionally, to rapidly detect health-promoting flavonol antioxidants in Brassica plants.

  3. A new flavonol C-glycoside and a rare bioactive lignanamide from Piper wallichii Miq. Hand.-Mazz.

    Science.gov (United States)

    Wang, Pei-Pei; Zhao, Guo-Wei; Xia, Wen; Han, En-Ji; Xiang, Lan

    2014-05-01

    This study was conducted to investigate the chemical constituents of Piper wallichii (Miq.) Hand.-Mazz. and evaluate their biological activity. Compounds were isolated by various column chromatographic methods, and their structures were elucidated on the basis of physical characteristics and spectral data. The 1, 1-diphenyl-2-picrylhydrazyl (DPPH)-scavenging activity and acetylcholinesterase (AChE)-inhibitory activity of the compounds were evaluated. Five compounds were obtained and identified as 8-C-β-D-glucopyranosylkaempferol-3-O-β-D-glucopyranoside (1), 1, 2-dihydro-6,8-dimethoxy-7-hydroxy-1-(3, 5-dimethoxy-4-hydroxyphenyl)-N(1), N(2)-bis-[2-(4-hydroxyphenyl)ethyl]-2, 3-naphthalene dicarboxamide (2), goniothalactam (3), aristololactam A IIIa (4) and piperlonguminine (5). Compound 1 was a new flavonol C-glycoside, 2 was a rare lignanamide, which was isolated from the family Piperaceae for the first time, and compound 3 was isolated from this plant for the first time. Among them, 2 showed potent DPPH-scavenging activity, with IC50 of 31.38 ± 0.97 μmol·L(-1); Compounds 2, 3, and 4 showed AChE inhibitory activity at 100 μmol·L(-1), with inhibition rates of 28.57% ± 1.47%, 18.48% ± 2.41% and 17.4% ± 3.03%, respectively.

  4. Flavonol Activation Defines an Unanticipated Ligand-Binding Site in the Kinase-RNase Domain of IRE1

    Energy Technology Data Exchange (ETDEWEB)

    Wiseman, R. Luke; Zhang, Yuhong; Lee, Kenneth P.K.; Harding, Heather P.; Haynes, Cole M.; Price, Joshua; Sicheri, Frank; Ron, David (Scripps); (Toronto); (NYUSM)

    2010-08-18

    Signaling in the most conserved branch of the endoplasmic reticulum (ER) unfolded protein response (UPR) is initiated by sequence-specific cleavage of the HAC1/XBP1 mRNA by the ER stress-induced kinase-endonuclease IRE1. We have discovered that the flavonol quercetin activates yeast IRE1's RNase and potentiates activation by ADP, a natural activating ligand that engages the IRE1 nucleotide-binding cleft. Enzyme kinetics and the structure of a cocrystal of IRE1 complexed with ADP and quercetin reveal engagement by quercetin of an unanticipated ligand-binding pocket at the dimer interface of IRE1's kinase extension nuclease (KEN) domain. Analytical ultracentrifugation and crosslinking studies support the preeminence of enhanced dimer formation in quercetin's mechanism of action. These findings hint at the existence of endogenous cytoplasmic ligands that may function alongside stress signals from the ER lumen to modulate IRE1 activity and at the potential for the development of drugs that modify UPR signaling from this unanticipated site.

  5. Quantum Chemical Calculations on the Interaction between Flavonol and Functional Monomers (Methacrylic Acid and 4-Vinylpyridine in Molecularly Imprinted Polymers

    Directory of Open Access Journals (Sweden)

    Luis Enrique Gómez-Pineda

    2010-06-01

    Full Text Available Quantum chemical calculations were performed to characterize the interaction of the flavonol molecule (FL with methacrylic acid (MAA and 4-vinylpyridine (4VPy in the formation of imprinted polymers. The polarizable continuum model (PCM was used to gain insight on the type of interaction between the reactant molecules under vacuum conditions and in the presence of different solvents. The effect of solvent on the pre-polymerization complex formation was evaluated through the stability energy, in which chloroform behaves as the best solvent for the synthesis of the imprinted polymers since it facilitates the reaction by lowering its degree of stabilization. The reactivity was analyzed in terms of the electrostatic surface potential (ESP and Mulliken charge. By means of these results, it has been possible to determine two potential recognition sites for the interaction of the MAA monomer and one for the 4VPy in relation to the strength of interaction with FL. In this concern, the interaction of the system FL-MAA is stronger than FL-4VPy.

  6. Two new flavonol glycosides and a metabolite profile of Bryophyllum pinnatum, a phytotherapeutic used in obstetrics and gynaecology.

    Science.gov (United States)

    Fürer, Karin; Raith, Melanie; Brenneisen, Rudolf; Mennet, Monica; Simões-Wüst, Ana Paula; von Mandach, Ursula; Hamburger, Matthias; Potterat, Olivier

    2013-11-01

    Bryophyllum pinnatum is a succulent perennial plant native to Madagascar which is used in anthroposophical medicine to treat psychiatric disorders and as a tocolytic agent to prevent premature labour. We performed a metabolite profiling study in order to obtain a comprehensive picture of the constituents in B. pinnatum leaves and to identify chromatographic markers for quality control and safety assessment of medicinal preparations. Preliminary HPLC-PDA-ESIMS analyses revealed that flavonoid glycosides were the main UV-absorbing constituents in the MeOH extract of B. pinnatum. Two phenolic glucosides, syringic acid β-D-glucopyranosyl ester (1) and 4'-O-β-D-glucopyranosyl-cis-p-coumaric acid (2), as well as nine flavonoids (3-11) including kaempferol, quercetin, myricetin, acacetin, and diosmetin glycosides were unambiguously identified by 1H and 2D NMR analysis after isolation from a MeOH extract. The flavonol glycosides quercetin 3-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside 7-O-β-D-glucopyranoside (3) and myricetin 3-O-α-L-arabinopyranosyl-(1 → 2)-α-L-rhamnopyranoside (4) were new natural products. With the aid of HPLC-PDA-APCIMS and authentic references isolated from the related species B. daigremontianum, the presence of four bufadienolides, bersaldegenin-1-acetate (12), bryophyllin A (13), bersaldegenin-3-acetate (14), and bersaldegenin-1,3,5-orthoacetate (15) was detected in B. pinnatum.

  7. Determination of flavonol glycosides in green tea, oolong tea and black tea by UHPLC compared to HPLC.

    Science.gov (United States)

    Jiang, Heyuan; Engelhardt, Ulrich H; Thräne, Claudia; Maiwald, Beate; Stark, Janina

    2015-09-15

    An UHPLC method for the determination of flavonol glycosides (FOG) from green and oolong tea vs. black tea has been developed for the first time. Sample clean-up method by means of polyamide column chromatography was optimized with multiple-step elution. Using UHPLC and HPLC with gradient elution and photodiode array detection, eighteen FOG compounds were determined with the aid of electrospray tandem mass spectrometry. These FOG compounds were qualified on both UHPLC and HPLC, and this UHPLC method successfully separated rutin (quercetin-3-O-rutinoside) and K-grg (kaempferol-3-O-glucorhamnoglucoside) while conventional HPLC method did not. The total amounts of FOG compounds in the tea samples were 2.32-5.67g/kg dry weight (calculated as aglycones), and there is no significant difference for the total FOG content among green tea, oolong tea and black tea. However, kaempferol glycosides are more abundant in green teas, while oolong tea has more quercetin and myricetin glycosides. In black tea quercetin glycosides were most abundant.

  8. Flavonol-rich dark cocoa significantly decreases plasma endothelin-1 and improves cognitive responses in urban children.

    Directory of Open Access Journals (Sweden)

    Lilian eCalderon-Garciduenas

    2013-08-01

    Full Text Available Air pollution exposures are linked to systemic inflammation, cardiovascular and respiratory morbidity and mortality, neuroinflammation and neuropathology in young urbanites. In particular, most Mexico City Metropolitan Area (MCMA children exhibit subtle cognitive deficits, and neuropathology studies show 40% of them exhibiting frontal tau hyperphosphorylation and 51% amyloid-β diffuse plaques (compared to 0% in low pollution control children. We assessed whether a short cocoa intervention can be effective in decreasing plasma endothelin 1 (ET-1 and/or inflammatory mediators in MCMA children. Thirty g of dark cocoa with 680 mg of total flavonols were given daily for 10.11± 3.4 days (range 9 to 24 days to 18 children (10.55yrs, SD =1.45; 11F/7M. Key metabolite ratios in frontal white matter and in hippocampus pre and during cocoa intervention were quantified by magnetic resonance spectroscopy. ET-1 significantly decreased after cocoa treatment (p=0.0002. Fifteen children (83% showed a marginally significant individual improvement in one or both of the applied simple short memory tasks. Endothelial dysfunction is a key feature of exposure to particulate matter and decreased endothelin-1 bioavailability is likely useful for brain function in the context of air pollution. Our findings suggest that cocoa interventions may be critical for early implementation of neuroprotection of highly exposed urban children. Multi-domain nutraceutical interventions could limit the risk for endothelial dysfunction, cerebral hypoperfusion, neuroinflammation, cognitive deficits, structural volumetric detrimental brain effects, and the early development of the neuropathological hallmarks of Alzheimer’s and Parkinson’s diseases.

  9. Cellular mechanisms underlying the laxative effect of flavonol naringenin on rat constipation model.

    Directory of Open Access Journals (Sweden)

    Zi-Huan Yang

    Full Text Available BACKGROUND & AIMS: Symptoms of constipation are extremely common, especially in the elderly. The present study aim to identify an efficacious treatment strategy for constipation by evaluating the secretion-promoting and laxative effect of a herbal compound, naringenin, on intestinal epithelial anion secretion and a rat constipation model, respectively. METHODS/PRINCIPAL FINDINGS: In isolated rat colonic crypts, mucosal addition of naringenin (100 microM elicited a concentration-dependent and sustained increase in the short-circuit current (I(SC, which could be inhibited in Cl- free solution or by bumetanide and DPC (diphenylamine-2-carboxylic acid, but not by DIDS (4, 4'- diisothiocyanatostilbene-2, 2'-disulfonic acid. Naringenin could increase intracellular cAMP content and PKA activity, consisted with that MDL-12330A (N-(Cis-2-phenyl-cyclopentyl azacyclotridecan-2-imine-hydrochloride pretreatment reduced the naringenin-induced I(SC. In addition, significant inhibition of the naringenin-induced I(SC by quinidine indicated that basolateral K+ channels were involved in maintaining this cAMP-dependent Cl- secretion. Naringenin-evoked whole cell current which exhibited a linear I-V relationship and time-and voltage- independent characteristics was inhibited by DPC, indicating that the cAMP activated Cl- conductance most likely CFTR (cystic fibrosis transmembrane conductance regulator was involved. In rat constipation model, administration of naringenin restored the level of fecal output, water content and mucus secretion compared to loperamide-administrated group. CONCLUSIONS: Taken together, our data suggest that naringenin could stimulate Cl- secretion in colonic epithelium via a signaling pathway involving cAMP and PKA, hence provide an osmotic force for subsequent colonic fluid secretion by which the laxative effect observed in the rat constipation model. Naringenin appears to be a novel alternative treatment strategy for constipation.

  10. Direct analysis of 18 flavonol glycosides, aglycones and terpene trilactones in Ginkgo biloba tablets by matrix solid phase dispersion coupled with ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry.

    Science.gov (United States)

    Liu, Xin-Guang; Yang, Hua; Cheng, Xiao-Lan; Liu, Lei; Qin, Yong; Wang, Qi; Qi, Lian-Wen; Li, Ping

    2014-08-01

    Analysis and quality control of Ginkgo biloba have been comprehensively studied. However, little attention has been devoted to the simultaneous extraction and analysis of flavonols and terpene trilactones, especially for direct quantification of flavonol glycosides. This work described a rapid strategy for one-step extraction and quantification of the components. A matrix solid phase dispersion (MSPD) method was designed for the extraction of ginkgo ingredients and compared with the heat-reflux and ultrasonic extraction methods. An ultra-high performance liquid chromatography (UHPLC)-tandem-triple-quadrupole-mass spectrometry (QQQ-MS) method was developed for detection of the 18 components, including 10 original flavonol glycosides, 3 aglycones, and 5 lactones. Subsequently, the proposed strategy was used for the analysis of 12 G. biloba tablets. Results showed that MSPD produced comparable extraction efficiency but consumed less time and required lower solvent volumes compared with conventional methods. Without hydrolysis, the concentration detected was much closer to the original in the sample. The total flavonol glycoside contents in ginkgo tablets ranged from 3.59 to 125.21μgmg(-1), and the terpene trilactone varied from 3.45 to 57.8μgmg(-1) among different manufacturers. In conclusion, the proposed MSPD and UHPLC-QQQ-MS is rapid and sensitive in providing comprehensive profile of chemical constituents especially the genuine flavonol glycosides for improved quality control of ginkgo products.

  11. Phenylalanine ammonia-lyase, flavanone 3β-hydroxylase and flavonol synthase enzyme activity by a new in vitro assay method in berry fruits.

    Science.gov (United States)

    Flores, Gema; De la Peña Moreno, Fernando; Blanch, Gracia Patricia; Del Castillo, Maria Luisa Ruiz

    2014-06-15

    An HPLC method for the determination of phenylalanine ammonia-lyase, flavanone 3β-hydroxylase and flavonol synthase enzyme activity is proposed. This method is based on the determination of the compounds produced and consumed on the enzymatic reaction in just one chromatographic analysis. Optimisation of the method considered kinetic studies to establish the incubation time to perform the assay. The method here described proved to be an interesting approach to measure the activities of the three enzymes simultaneously increasing the rapidity, selectivity and sensitivity over other exiting methods. The enzyme activity method developed was applied to strawberry, raspberry, blackberry, redcurrant and blackcurrant fruits.

  12. The flavonoid pathway regulates the petal colors of cotton flower.

    Directory of Open Access Journals (Sweden)

    Jiafu Tan

    Full Text Available Although biochemists and geneticists have studied the cotton flower for more than one century, little is known about the molecular mechanisms underlying the dramatic color change that occurs during its short developmental life following blooming. Through the analysis of world cotton germplasms, we found that all of the flowers underwent color changes post-anthesis, but there is a diverse array of petal colors among cotton species, with cream, yellow and red colors dominating the color scheme. Genetic and biochemical analyses indicated that both the original cream and red colors and the color changes post-anthesis were related to flavonoid content. The anthocyanin content and the expression of biosynthesis genes were both increased from blooming to one day post-anthesis (DPA when the flower was withering and undergoing abscission. Our results indicated that the color changes and flavonoid biosynthesis of cotton flowers were precisely controlled and genetically regulated. In addition, flavonol synthase (FLS genes involved in flavonol biosynthesis showed specific expression at 11 am when the flowers were fully opened. The anthocyanidin reductase (ANR genes, which are responsible for proanthocyanidins biosynthesis, showed the highest expression at 6 pm on 0 DPA, when the flowers were withered. Light showed primary, moderate and little effects on flavonol, anthocyanin and proanthocyanidin biosynthesis, respectively. Flavonol biosynthesis was in response to light exposure, while anthocyanin biosynthesis was involved in flower color changes. Further expression analysis of flavonoid genes in flowers of wild type and a flavanone 3-hydroxylase (F3H silenced line showed that the development of cotton flower color was controlled by a complex interaction between genes and light. These results present novel information regarding flavonoids metabolism and flower development.

  13. Comparative Characterization of Total Flavonol Glycosides and Terpene Lactones at Different Ages, from Different Cultivation Sources and Genders of Ginkgo biloba Leaves

    Directory of Open Access Journals (Sweden)

    Yong Qin

    2012-08-01

    Full Text Available The extract from Ginkgo biloba leaves has become a very popular plant medicine and herbal supplement for its potential benefit in alleviating symptoms associated with peripheral vascular disease, dementia, asthma and tinnitus. Most research on G. biloba leaves focus on the leaves collected in July and August from four to seven year-old trees, however a large number of leaves from fruit cultivars (trees older than 10 years are ignored and become obsolete after fruit harvest season (November. In this paper, we expand the tree age range (from one to 300 years and first comparatively analyze the total flavonol glycosides and terpene lactones at different ages, from different cultivation sources and genders of G. biloba leaves collected in November by using the validated HPLC-ELSD and HPLC-PDA methods. The results show that the contents of total terpene lactones and flavonol glycosides in the leaves of young ginkgo trees are higher than those in old trees, and they are higher in male trees than in female trees. Geographical factors appear to have a significant influence on the contents as well. These results will provide a good basis for the comprehensive utilization of G. biloba leaves, especially the leaves from fruit cultivars.

  14. Ground and excited state proton transfer of the bioactive plant flavonol robinetin in a protein environment: spectroscopic and molecular modeling studies.

    Science.gov (United States)

    Pahari, Biswa Pathik; Chaudhuri, Sudip; Chakraborty, Sandipan; Sengupta, Pradeep K

    2015-02-12

    We performed spectroscopic and molecular modeling studies to explore the interaction of the bioactive plant flavonol robinetin (3,7,3',4',5'-OH flavone), with the carrier protein human serum albumin (HSA). Multiparametric fluorescence sensing, exploiting the intrinsic "two color" fluorescence of robinetin (comprising excited state intramolecular proton transfer (ESIPT) and charge transfer (CT) emissions) reveals that binding to HSA significantly affects the emission and excitation profiles, with strongly blue-shifted (∼29 nm) normal fluorescence and remarkable increase in the ESIPT fluorescence anisotropy (r) and lifetime (τ). Flavonol-induced HSA (tryptophan) fluorescence quenching data yield the dynamic quenching constant (KD) as 5.42 × 10(3) M(-1) and the association constant (Ks) as 5.59 × 10(4) M(-1). Time-resolved fluorescence anisotropy decay studies show dramatic (∼170 times) increase in the rotational correlation time (τ(rot)), reflecting greatly enhanced restrictions in motion of robinetin in the protein matrix. Furthermore, prominent induced circular dichroism (ICD) bands appear, indicating that the chiral environment of HSA strongly perturbs the electronic transitions of the intrinsically achiral robinetin molecule. Molecular docking calculations suggest that robinetin binds in subdomain IIA of HSA, where specific interactions with basic residues promote ground state proton abstraction and stabilize an anionic species, which is consistent with spectroscopic observations.

  15. Interplay between excited-state intramolecular proton transfer and charge transfer in flavonols and their use as protein-binding-site fluorescence probes

    Energy Technology Data Exchange (ETDEWEB)

    Sytnik, A.; Gormin, D.; Kasha, M. (Florida State Univ., Tallahassee, FL (United States))

    1994-12-06

    A comparative study is presented of competitive fluorescences of three flavonols, 3-hydroxyflavone, 3,3[prime],4[prime],7-tetrahydroxyflavone (fisetin), and 4[prime]-diethylamino-3-hydroxyflavone (DHF). The normal fluorescence S[sub 1] [yields] S[sub 0] (400-nm region) is largely replaced by the proton-transfer tautomer fluorescence S[prime][sub 1] [yields] S[prime][sub 0] in the 550-nm region for all three of the flavonols in aprotic solvents at room temperature. For DHF in polar solvents the normal fluorescence becomes a charge-transfer fluorescence (460-500 nm) which competes strongly with the still dominant proton-transfer fluorescence (at 570 nm). In protic solvents, and at 77 K, the interference with intramolecular hydrogen bonding gives rise to greatly enhanced normal fluorescence, lowering the quantum yield of proton-transfer fluorescence. The utility of DHF as a discriminating fluorescence probe for protein binding sites is suggested by the strong dependence of the charge-transfer fluorescence on polarity of the environment and by various static and dynamic parameters of the charge-transfer and proton-transfer fluorescence which can be determined. 49 refs., 6 figs., 1 tab.

  16. Transfer and Mass Balance of Ellagitannins, Anthocyanins, Flavan-3-ols, and Flavonols during the Processing of Red Raspberries (Rubus idaeus L.) to Juice.

    Science.gov (United States)

    Sójka, Michał; Macierzyński, Jakub; Zaweracz, Wojciech; Buczek, Maria

    2016-07-13

    The putative health benefits of raspberries and raspberry-based products are potentially attributable to the presence of polyphenolic compounds, such as ellagitannins, anthocyanins, flavanols, and flavonols. Their content in the products of raspberry processing into juice may be affected by the fruit cultivar, technological process parameters, and the properties of the polyphenolics themselves. The objective of the study was to investigate the composition and quantity of the above polyphenolics in raspberries and the products of their processing (that is, juice and press cake, including its seed and seedless fractions). The study also examined the relationship between the molecular mass of ellagitannins and their transfer to juice. The average percentage contributions of ellagitannins, anthocyanins, flavanols, and flavonols to total polyphenolics in the fruits were 64.2%, 17.1%, 16.9%, and 1.8%, respectively. Analysis of raspberry products showed that the dominant compounds in juice were anthocyanins, with 65.1% contribution to total polyphenolics, while in raspberry press cake, they were tannins (98.0%, mainly ellagitannin including lambertianin C and sanguiin H-6). As shown by our mass-balance calculations, on average, 68.1% of ellagitannins and 87.7% of flavanols were retained in press cake, especially in its seedless fraction. In addition, a significant negative correlation was found between the molecular mass of ellagitannins and their transfer to juice. An increase in molecular mass from 1568 to 2805 Da resulted in a more than 10-fold decrease in ellagitannin transfer.

  17. Complementary cereals and legumes for health: Synergistic interaction of sorghum flavones and cowpea flavonols against LPS-induced inflammation in colonic myofibroblasts.

    Science.gov (United States)

    Agah, Shima; Kim, Hyemee; Mertens-Talcott, Susanne U; Awika, Joseph M

    2017-07-01

    Cereals and legumes are traditionally consumed together in many cultures, and may provide complementary health benefits beyond what is known about improved indispensable amino acid intake. Here, we use an in vitro model of inflammatory pathways to investigate whether the different flavonoids in sorghum and cowpea could synergistically reduce inflammation. Interactive effect of combining apigenin and quercetin, as well as extracts (70% acetone, v/v) from a flavone-dominated white sorghum and flavonol-dominated white cowpea, against LPS-induced NF-κB and downstream cytokines (TNF-α, IL-6, IL-8) gene and protein expression was evaluated using the CCD18Co colon myofibroblasts. Combination of apigenin and quercetin, and sorghum and cowpea extracts synergistically downregulated LPS-induced NF-κB gene and protein expression in a dose-dependent manner, with additive effect producing IC50 values that were 14.6 and 14.0 times, respectively, higher than 1:1 combined treatments. Similar strong synergistic interactions were observed for the downstream cytokines (IC50 values for additive effect 8.3-21 times higher than combined treatments). Furthermore, the ratios of the different combined treatments significantly affected the magnitude of synergy. Combining the structurally related cereal flavones and legume flavonols elicit strong synergistic anti-inflammatory response in LPS-stimulated nonmalignant colonocytes, likely by targeting interdependent mechanisms. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Interaction of moderate UV-B exposure and temperature on the formation of structurally different flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica).

    Science.gov (United States)

    Neugart, Susanne; Fiol, Michaela; Schreiner, Monika; Rohn, Sascha; Zrenner, Rita; Kroh, Lothar W; Krumbein, Angelika

    2014-05-07

    Kale has a high number of structurally different flavonol glycosides and hydroxycinnamic acid derivatives. In this study we investigated the interaction of moderate UV-B radiation and temperature on these compounds. Kale plants were grown at daily mean temperatures of 5 or 15 °C and were exposed to five subsequent daily doses (each 0.25 kJ m(-2) d(-1)) of moderate UV-B radiation at 1 d intervals. Of 20 phenolic compounds, 11 were influenced by an interaction of UV-B radiation and temperature, e.g., monoacylated quercetin glycosides. Concomitantly, enhanced mRNA expression of flavonol 3'- hydroxylase showed an interaction of UV-B and temperature, highest at 0.75 kJ m(-2) and 15 °C. Kaempferol glycosides responded diversely and dependent on, e.g., the hydroxycinnamic acid residue. Compounds containing a catechol structure seem to be favored in the response to UV-B. Taken together, subsequent exposure to moderate UV-B radiation is a successful tool for enhancing the flavonoid profile of plants, and temperature should be considered.

  19. Computer-aided method for identification of major flavone/flavonol glycosides by high-performance liquid chromatography-diode array detection-tandem mass spectrometry (HPLC-DAD-MS/MS).

    Science.gov (United States)

    Wang, Zhengfang; Lin, Longze; Harnly, James M; Harrington, Peter de B; Chen, Pei

    2014-11-01

    A new computational tool is proposed here for tentatively identifying major (UV quantifiable) flavone/flavonol glycoside peaks of high performance liquid chromatogram (HPLC)-diode array detection (DAD)-tandem mass spectrometry (MS/MS) profiles based on a MATLAB-based script implementing an in-house algorithm. The HPLC-DAD-MS/MS profiles of red onion, Chinese lettuce, carrot leaf, and celery seed extracts were analyzed by the proposed computer-aided screening method for identifying possible flavone/flavonol glycoside peaks from the HPLC-UV and MS total ion current (TIC) chromatograms. The number of identified flavone/flavonol glycoside peaks of the HPLC-UV chromatograms is four, four, six, and nine for red onion, Chinese lettuce, carrot leaf, and celery seed, respectively. These results have been validated by human(s) experts. For the batch processing of nine HPLC-DAD-MS/MS profiles of celery seed extract, the entire script execution time was within 15 s while manual calculation of only one HPLC-DAD-MS/MS profile by a flavonoid expert could take hours. Therefore, this MATLAB-based screening method is able to facilitate the HPLC-DAD-MS/MS analysis of flavone/flavonol glycosides in plants to a large extent.

  20. A Comparative Study of Flavonols Content in Mulberry Purple Wine by Different Pretreatment%不同前处理发酵的桑椹紫酒中黄酮醇物质的比较研究

    Institute of Scientific and Technical Information of China (English)

    李岳珍; 侯钰; 陈欣悦; 陈有君

    2012-01-01

    采用反相高效液相色谱检测不同前处理发酵的桑椹紫酒中黄酮醇的含量,并与葡萄酒中黄酮醇的含量进行对比。结果表明,不同前处理桑椹紫酒中各类黄酮醇的含量除山萘酚,其余均差异极显著。桑椹紫酒中可以检测出10种黄酮醇。其中,槲皮素、杨梅素与葡萄酒中的含量相当,其余8种黄酮醇:山萘酚、异鼠李素、高良姜素、芦丁、非瑟酮、桑色素、鼠李素、芹菜素含量均比葡萄酒中的含量要高,且均在0.54 mg/L以上。%The content of flavonols in mulberry purple wine by different pretreatment was measured by reversed-phase high performance liquid chromatography detection,and then compared with flavonol content in grape wine.The results showed that there was evident difference in flavonol content in various types except kaempferol in mulberry wine by different pretreatment.There were ten kinds of flavonols detected in mulberry purple wine.Among them,the content of quercetin was equivalent to the content of myricetin,and the content of the other 8 kinds of flavonols including kaempferol,isorhamnetin,galangin,rutin,fisetin,morin,fhamnetin,and apigenin(their content was above 0.54 mg/L)was higher than that in grape wine.

  1. Increase in flavan-3-ols by silencing flavonol synthase mRNA affects the transcript expression and activity levels of antioxidant enzymes in tobacco.

    Science.gov (United States)

    Mahajan, M; Joshi, R; Gulati, A; Yadav, S K

    2012-09-01

    Flavonoids are plant secondary metabolites widespread throughout the plant kingdom involved in many physiological and biochemical functions. Amongst the flavonoids, flavan-3-ols (catechin and epicatechin) are known for their direct free radical scavenging activity in vitro, but studies on their antioxidant potential and interaction with antioxidant enzymes in vivo are lacking. Here, the flavonoid pathway was engineered by silencing a gene encoding flavonol synthase (FLS) in tobacco to direct the flow of metabolites towards production of flavan-3-ols. FLS silencing reduced flavonol content 17-53%, while it increased catechin and epicatechin content 51-93% and 18-27%, respectively. The silenced lines showed a significant increase in expression of genes for dihydroflavonol reductase and anthocyanidin synthase, a downstream gene towards epicatechin production, with no significant change in expression of other genes of the flavonoid pathway. Effects of accumulation of flavan-3-ols in FLS silenced lines on transcript level and activities of antioxidant enzymes were studied. Transcripts of the antioxidant enzymes glutathione reductase (GR), ascorbate peroxidase (APx), and catalase (CAT) increased, while glutathione-S-transferase (GST), decreased in FLS silenced lines. Enhanced activity of all the antioxidant enzymes was observed in silenced tobacco lines. To validate the affect of flavan-3-ols on the antioxidant system, in vitro experiments were conducted with tobacco seedlings exposed to two concentrations of catechin (10  and 50 μm) for 2 days. In vitro exposed seedlings produced similar levels of transcripts and activity of antioxidant enzymes as FLS silenced seedlings. Results suggest that flavan-3-ols (catechin) might be increasing activity of GR, Apx and CAT by elevating their mRNAs levels. Since these enzymes are involved in scavenging of reactive oxygen species, this strategy would help in tailoring crops for enhanced catechin production as well as making

  2. Comparison of Conventional Microwave and Focused Microwave-assisted Extraction to Enhance the Efficiency of the Extraction of Antioxidant Flavonols from Jocote Pomace (Spondias purpurea L.).

    Science.gov (United States)

    Reis, Letícia C B; Carneiro, Larissa M; Branco, Carla R C; Branco, Alexsandro

    2015-06-01

    Jocote (Spondias purpurea L.) is rich in phenolic compounds which have antioxidant properties. The focused microwave-assisted extraction (FMAE) was compared with the conventional microwave-assisted extraction (MAE) to obtain flavonols from jocote pomace. The effects of parameters such as the extraction time, the temperature and the composition of the solvent mixture (i.e., the ethanol to water ration) were evaluated and optimized using a statistical experimental design approach. Response surface methodology (RSM) was applied to determine the important effects and interactions of these independent variables on the extractive yield and quantification of some flavonoids. In addition, the antioxidant activity was analyzed. The total phenolic and flavonoid content was determined according to the Folin-Ciocalteu and aluminum chloride methods, respectively. The free radical scavenging activity of the extract was evaluated according to the DPPH assay. The results showed that the optimum extracting parameters used FMAE with extraction time of 20 min, temperature of 68 °C and ethanol composition of 80% in water. Under these conditions, a yield of 3.42% was obtained. Rutin and quercetin were quantified (0.19 mg/mL and 0.024 mg/mL, respectively) through HPLC-DAD. The total phenol and flavonoid contents were found to be 0.897 g GAE/g and 1.271 g QE/g, respectively. In the DPPH scavenging assay, the IC50 value of the extract occurred at 43.10 μg/mL. This study shows that FMAE is suitable as an efficient extraction procedure for the extraction of flavonols from jocote pomace.

  3. Estimated dietary intakes of flavonols, flavanones and flavones in the European Prospective Investigation into Cancer and Nutrition (EPIC) 24 hour dietary recall cohort.

    Science.gov (United States)

    Zamora-Ros, Raul; Knaze, Viktoria; Luján-Barroso, Leila; Slimani, Nadia; Romieu, Isabelle; Fedirko, Veronika; de Magistris, Maria Santucci; Ericson, Ulrica; Amiano, Pilar; Trichopoulou, Antonia; Dilis, Vardis; Naska, Androniki; Engeset, Dagrun; Skeie, Guri; Cassidy, Aedin; Overvad, Kim; Peeters, Petra H M; Huerta, José María; Sánchez, María-José; Quirós, J Ramón; Sacerdote, Carlotta; Grioni, Sara; Tumino, Rosario; Johansson, Gerd; Johansson, Ingegerd; Drake, Isabel; Crowe, Francesca L; Barricarte, Aurelio; Kaaks, Rudolf; Teucher, Birgit; Bueno-de-Mesquita, H Bas; van Rossum, Caroline T M; Norat, Teresa; Romaguera, Dora; Vergnaud, Anne-Claire; Tjønneland, Anne; Halkjær, Jytte; Clavel-Chapelon, Françoise; Boutron-Ruault, Marie-Christine; Touillaud, Marina; Salvini, Simonetta; Khaw, Kay-Thee; Wareham, Nicholas; Boeing, Heiner; Förster, Jana; Riboli, Elio; González, Carlos A

    2011-12-01

    Flavonols, flavanones and flavones (FLAV) are sub-classes of flavonoids that exert cardioprotective and anti-carcinogenic properties in vitro and in vivo. We aimed to estimate the FLAV dietary intake, their food sources and associated lifestyle factors in ten European countries participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. FLAV intake and their food sources for 36 037 subjects, aged between 35 and 74 years, in twenty-seven study centres were obtained using standardised 24 h dietary recall software (EPIC-SOFT). An ad hoc food composition database on FLAV was compiled using data from US Department of Agriculture and Phenol-Explorer databases and was expanded using recipes, estimations and flavonoid retention factors in order to increase its correspondence with the 24 h dietary recall. Our results showed that the highest FLAV-consuming centre was the UK health-conscious group, with 130·9 and 97·0 mg/d for men and women, respectively. The lowest FLAV intakes were 36·8 mg/d in men from Umeå and 37·2 mg/d in women from Malmö (Sweden). The flavanone sub-class was the main contributor to the total FLAV intake ranging from 46·6 to 52·9 % depending on the region. Flavonols ranged from 38·5 to 47·3 % and flavones from 5·8 to 8·6 %. FLAV intake was higher in women, non-smokers, increased with level of education and physical activity. The major food sources were citrus fruits and citrus-based juices (especially for flavanones), tea, wine, other fruits and some vegetables. We concluded that the present study shows heterogeneity in intake of these three sub-classes of flavonoids across European regions and highlights differences by sex and other sociodemographic and lifestyle factors.

  4. Low and moderate photosynthetically active radiation affects the flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica) dependent on two low temperatures.

    Science.gov (United States)

    Neugart, Susanne; Fiol, Michaela; Schreiner, Monika; Rohn, Sascha; Zrenner, Rita; Kroh, Lothar W; Krumbein, Angelika

    2013-11-01

    Kale (Brassica oleracea var. sabellica) contains a large number of naturally occurring structurally different non-acylated and acylated flavonol glycosides as well as hydroxycinnamic acid derivatives. The objective of this study was to determine the effect of low and moderate photosynthetic active radiation (PAR) and how these levels interact with low temperature in these phenolic compounds. Juvenile kale plants were treated with PAR levels from 200 to 800 μmol m(-2) s(-1) at 5 and 10 °C under defined conditions in climate chambers. Of the investigated 20 compounds, 11 and 17 compounds were influenced by PAR and temperature, respectively. In addition, an interaction between PAR and temperature was found for eight compounds. The response of the phenolic compounds to PAR was structure-dependent. While quercetin triglycosides increased with higher PAR at 5 and 10 °C, the kaempferol triglycosides exhibited the highest concentrations at 400 μmol m(-2) s(-1). In contrast, kaempferol diglycosides exhibited the highest concentrations at increased PAR levels of 600 and 800 μmol m(-2) s(-1) at 10 °C. However, key genes of flavonol biosynthesis were influenced by temperature but remained unaffected by PAR. Furthermore, there was no interaction between the PAR level and the low temperature in the response of hydroxycinnamic acid derivatives in kale with the exception of caffeoylquinic acid, which decreased with higher PAR levels of 600 and 800 μmol m(-2) s(-1) and at a lower temperature. In conclusion, PAR and its interaction with temperature could be a suitable tool for modifying the profile of phenolic compounds.

  5. The Role of Selected Flavonols in Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Receptor–1 (TRAIL-R1 Expression on Activated RAW 264.7 Macrophages

    Directory of Open Access Journals (Sweden)

    Monika Warat

    2015-01-01

    Full Text Available Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand Receptors (TRAIL-R are an important factor of apoptosis in cancer cells. There are no data about the effect of flavonols on the receptor expression on a surface of macrophage like cells. In this study, the expression level of TRAIL-R1 on murine RAW264.7 macrophages in the presence of selected flavonols: galangin, kaempferol, kaempferide and quercetin, which differ from their phenyl ring substituents, were studied. The expression of TRAIL-R1 death receptors on non-stimulated and lipopolysaccharide (LPS-stimulated macrophages was determined using flow cytometry. The results suggested that compounds being tested can modulate TRAIL-R1 expression and can enhance TRAIL-mediated apoptosis.

  6. Flavonols and antioxidant activity of Physalis peruviana L. fruit at two maturity stages - doi: 10.4025/actascitechnol.v35i2.13265

    Directory of Open Access Journals (Sweden)

    Silvana Licodiedoff

    2013-04-01

    Full Text Available Since the characteristics of the fresh fruit of cape gooseberry (Physalis peruviana L. are little known, its valorization and use are impaired. The fruit’s bioactive compounds at two stages of maturity, start and end of maturity, are evaluated, with differentiating colors between green-yellow and orange for two sizes of the fruit. The ratio between sugars and acids increased from the beginning to the end of maturity. Quercetin was not found in the samples. Nevertheless, rutin was predominant in small and large size mature sample, followed by greenish yellow (start of maturity color of the small size fruit, with values ranging between 6.904 and 6.761 mg g-1 and 5.891 to 4.465 mg g-1, respectively. Myricetin rates ranged between 1.085 and 1.170 mg g-1 and 1.110 to 1.309 mg g-1 for greenish yellow and orange fruits, respectively. These results characterize the fruit of Physalis peruviana L. as a source of phenolic compounds in food. Antioxidant activity, influenced by the different stages of fruit ripening, is correlated to a higher content of the flavonols rutin and myricetin. Maturity degree and fruit size affect the fruit’s chemical characteristics.  

  7. Simultaneous extraction and separation of flavonols and flavones from Chamaecyparis obtusa by multi-phase extraction using an ionic liquid-modified microsphere polymer.

    Science.gov (United States)

    Tian, Minglei; Bi, Wentao; Row, Kyung Ho

    2012-01-01

    Flavonols and flavones, especially quercitrin, myricetin and amentoflavone, are the main anti-bacterial and anti-cancer compounds in Chamaecyparis obtuse. Multi-phase extraction is a new method that can extract and separate target compounds simultaneously. An amino ionic liquid immobilised microsphere polymer was used as a multi-phase extraction sorbent to extract and separate quercitrin, myricetin and amentoflavone from Chamaecyparis obtusa. The sorbent and Chamaecyparis obtusa powder were packed into a single cartridge. Using a fixed volume of methanol with five repetitions, the target compounds were extracted from the powder to the sorbent. The sorbent was then washed with n-hexane to remove any interfering species and the target compounds were eluted sequentially using water, methanol and methanol containing 1% acetic acid (vol.). Under the optimised conditions, 0.45 mg/g of quercitrin, 0.18 mg/g of myricetin and 0.12 mg/g of amentoflavone from 2.0 g of powder were obtained by multi-phase extraction using 0.3 g of sorbent. The method described has a low deviation error, requires a small amount of solvent and is highly selective and reproducible. Copyright © 2012 John Wiley & Sons, Ltd.

  8. Flavonol acylglycosides from flower of Albizia julibrissin and their inhibitory effects on lipid accumulation in 3T3-L1 cells.

    Science.gov (United States)

    Yahagi, Tadahiro; Daikonya, Akihiro; Kitanaka, Susumu

    2012-01-01

    Obesity is a serious health problem worldwide. We investigated the anti-obesity effect of the flower of Albizia julibrissin DURAZZ. (Leguminosae). A 90% EtOH extract of the flower inhibited adipogenesis in 3T3-L1 preadipocytes, as well as the activity of glycerol-3-phosphate dehydrogenase (GPDH) activity. New flavonol acylglycosides (1-4) and eighteen known compounds (5-22) were isolated by bioassay-directed fractionation. These new glycosides were elucidated to be 3″-(E)-p-coumaroylquercitrin (1), 3″-(E)-feruloylquercitrin (2), 3″-(E)-cinnamoylquercitrin (3), and 2″-(E)-cinnamoylquercitrin (4) on the basis of spectroscopic and chemical analysis. These compounds inhibited adipogenesis in 3T3-L1 preadipocytes. In particular, 2 exhibited potent inhibitory effects on triglyceride accumulation. Furthermore, GPDH activity was inhibited by 2. Additionally, 2 inhibited glucose uptake in 3T3-L1 adipocytes. These results indicate that the 90% EtOH extract and compounds isolated from the flower of A. julibrissin inhibit adipogenesis in 3T3-L1 preadipocytes and may have anti-obesity effect through the inhibition of preadipocyte differentiation.

  9. Identification of 3′,4′-Dimethoxy Flavonol-3-β-d-Glucopyranoside Metabolites in Rats by Liquid Chromatography-Electrospray Ionization Ion Trap Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Yuan Zhu

    2016-04-01

    Full Text Available A method using liquid chromatography-electrospray ionization ion trap mass spectrometry was established for the identification of metabolites in feces, urine and bile in rats after oral administration of 3′,4′-dimethoxy flavonol-3-β-d-glucopyranoside (abbreviated DF3G. Seven metabolites in rat feces, urine and bile were firstly identified on the basis of their MS fragmentation behaviors. Three metabolites were identified in the feces, 6 in the urine and 2 in the bile, which suggested that demethylation, deglycosylation and deglycosylation followed by glucuronide conjugation were the major metabolic pathways for DF3G in vivo. Hydrolyzation might be the first step in the absorption and metabolism of DF3G. The possible metabolic pathway was proposed for the first time. The established method was simple, reliable and sensitive, revealing that it could be used to rapidly screen and identify the structures of metabolites of DF3G to better understand its metabolism in vivo.

  10. Isorhamnetin, A Flavonol Aglycone from Ginkgo biloba L., Induces Neuronal Differentiation of Cultured PC12 Cells: Potentiating the Effect of Nerve Growth Factor

    Directory of Open Access Journals (Sweden)

    Sherry L. Xu

    2012-01-01

    Full Text Available Flavonoids, a group of compounds mainly derived from vegetables and herbal medicines, share a chemical resemblance to estrogen, and indeed some of which have been used as estrogen substitutes. In searching for possible functions of flavonoids, the neuroprotective effect in brain could lead to novel treatment, or prevention, for neurodegenerative diseases. Here, different subclasses of flavonoids were analyzed for its inductive role in neurite outgrowth of cultured PC12 cells. Amongst the tested flavonoids, a flavonol aglycone, isorhamnetin that was isolated mainly from the leaves of Ginkgo biloba L. showed robust induction in the expression of neurofilament, a protein marker for neurite outgrowth, of cultured PC12 cells. Although isorhamnetin by itself did not show significant inductive effect on neurite outgrowth of cultured PC12 cells, the application of isorhamnetin potentiated the nerve growth factor- (NGF-induced neurite outgrowth. In parallel, the expression of neurofilaments was markedly increased in the cotreatment of NGF and isorhamnetin in the cultures. The identification of these neurite-promoting flavonoids could be very useful in finding potential drugs, or food supplements, for treating various neurodegenerative diseases, including Alzheimer’s disease and depression.

  11. Isorhamnetin, A Flavonol Aglycone from Ginkgo biloba L., Induces Neuronal Differentiation of Cultured PC12 Cells: Potentiating the Effect of Nerve Growth Factor.

    Science.gov (United States)

    Xu, Sherry L; Choi, Roy C Y; Zhu, Kevin Y; Leung, Ka-Wing; Guo, Ava J Y; Bi, Dan; Xu, Hong; Lau, David T W; Dong, Tina T X; Tsim, Karl W K

    2012-01-01

    Flavonoids, a group of compounds mainly derived from vegetables and herbal medicines, share a chemical resemblance to estrogen, and indeed some of which have been used as estrogen substitutes. In searching for possible functions of flavonoids, the neuroprotective effect in brain could lead to novel treatment, or prevention, for neurodegenerative diseases. Here, different subclasses of flavonoids were analyzed for its inductive role in neurite outgrowth of cultured PC12 cells. Amongst the tested flavonoids, a flavonol aglycone, isorhamnetin that was isolated mainly from the leaves of Ginkgo biloba L. showed robust induction in the expression of neurofilament, a protein marker for neurite outgrowth, of cultured PC12 cells. Although isorhamnetin by itself did not show significant inductive effect on neurite outgrowth of cultured PC12 cells, the application of isorhamnetin potentiated the nerve growth factor- (NGF-)induced neurite outgrowth. In parallel, the expression of neurofilaments was markedly increased in the cotreatment of NGF and isorhamnetin in the cultures. The identification of these neurite-promoting flavonoids could be very useful in finding potential drugs, or food supplements, for treating various neurodegenerative diseases, including Alzheimer's disease and depression.

  12. Separation of four flavonol glycosides from Solanum rostratum Dunal using aqueous two-phase flotation followed by preparative high-performance liquid chromatography.

    Science.gov (United States)

    Chang, Lin; Shao, Qian; Xi, Xingjun; Chu, Qiao; Wei, Yun

    2017-02-01

    Aqueous two-phase flotation followed by preparative high-performance liquid chromatography was used to separate four flavonol glycosides from Solanum rostratum Dunal. In the aqueous two-phase flotation section, the effects of sublation solvent, solution pH, (NH4 )2 SO4 concentration in aqueous solution, cosolvent, N2 flow rate, flotation time, and volumes of the polyethylene glycol phase on the recovery were investigated in detail, and the optimal conditions were selected: 50 wt% polyethylene glycol 1000 ethanol solvent as the flotation solvent, pH 4, 350 g/L of (NH4 )2 SO4 concentration in aqueous phase, 40 mL/min of N2 flow rate, 30 min of flotation time, 10.0 mL of flotation solvent volume, and two times. After aqueous two-phase flotation concentration, the flotation products were purified by preparative high-performance liquid chromatography. The purities of the final products A and B were 98.1 and 99.0%. Product B was the mixture of three compounds based on the analysis of high-performance liquid chromatography at the temperature of 10°C, while product A was hyperoside after the identification by nuclear magnetic resonance. Astragalin, 3'-O-methylquercetin 3-O-β-d-galactopyranoside, and 3'-O-methylquercetin 3-O-β-d-glucopyranoside were obtained with the purity of 93.8, 97.1, and 99.2%, respectively, after the further separation of product B using preparative high-performance liquid chromatography.

  13. Determination of Flavonol Aglycones in Ginkgo biloba Dietary Supplement Crude Materials and Finished Products by High-Performance Liquid Chromatography: Single Laboratory Validation

    Science.gov (United States)

    Gray, Dean; LeVanseler, Kerri; Pan, Meide

    2008-01-01

    A single laboratory validation (SLV) was completed for a method to determine the flavonol aglycones quercetin, kaempferol, and isorhamnetin in Ginkgo biloba products. The method calculates total glycosides based on these aglycones formed following acid hydrolysis. Nine matrixes were chosen for the study, including crude leaf material, standardized dry powder extract, single and multiple entity finished products, and ethanol and glycerol tinctures. For the 9 matrixes evaluated as part of this SLV, the method appeared to be selective and specific, with no observed interferences. The simplified 60 min oven heating hydrolysis procedure was effective for each of the matrixes studied, with no apparent or consistent differences between 60, 75, and 90 min at 90°C. A Youden ruggedness trial testing 7 factors with the potential to affect quantitative results showed that 2 factors (volume hydrolyzed and test sample extraction/hydrolysis weight) were the most important parameters for control during sample preparation. The method performed well in terms of precision, with 4 matrixes tested in triplicate over a 3-day period showing an overall repeatability (relative standard deviation, RSD) of 2.3%. Analysis of variance testing at α = 0.05 showed no significant differences among the within- or between-group sources of variation, although comparisons of within-day (Sw), between-day (Sb), and total (St) precision showed that a majority of the standard deviation came from within-day determinations for all matrixes. Accuracy testing at 2 levels (approximately 30 and 90% of the determined concentrations in standardized dry powder extract) from 2 complex negative control matrixes showed an overall 96% recovery and RSD of 1.0% for the high spike, and 94% recovery and RSD of 2.5% for the low spike. HorRat scores were within the limits for performance acceptability, ranging from 0.4 to 1.3. Based on the performance results presented herein, it is recommended that this method progress

  14. Effects of Parsley (Petroselinum crispum) and its Flavonol Constituents, Kaempferol and Quercetin, on Serum Uric Acid Levels, Biomarkers of Oxidative Stress and Liver Xanthine Oxidoreductase Aactivity inOxonate-Induced Hyperuricemic Rats.

    Science.gov (United States)

    Haidari, Fatemeh; Keshavarz, Seid Ali; Mohammad Shahi, Majid; Mahboob, Soltan-Ali; Rashidi, Mohammad-Reza

    2011-01-01

    Increased serum uric acid is known to be a major risk related to the development of several oxidative stress diseases. The aim of this study was to investigate the effect of parsley, quercetin and kaempferol on serum uric acid levels, liver xanthine oxidoreductase activity and two non-invasive biomarkers of oxidative stress (total antioxidant capacity and malondialdehyde concentration) in normal and oxonate-induced hyperuricemic rats. A total of 60 male Wistar rats were randomly divided into ten equal groups; including 5 normal groups (vehicle, parsley, quercetin, kaempferol and allopurinol) and 5 hyperuricemic groups (vehicle, parsley, quercetin, kaempferol and allopurinol). Parsley (5 g/Kg), quercetin (5 mg/Kg), kaempferol (5 mg/Kg) and allopurinol (5 mg/Kg) were administrated to the corresponding groups by oral gavage once a day for 2 weeks. The results showed that parsley and its flavonol did not cause any significant reduction in the serum uric acid levels in normal rats, but significantly reduced the serum uric acid levels of hyperuricemic rats in a time-dependent manner. All treatments significantly inhibited liver xanthine oxidoreductase activity. Parsley, kaempferol and quercetin treatment led also to a significant increase in total antioxidant capacity and decrease in malondialdehyde concentration in hyperuricemic rats. Although the hypouricemic effect of allopurinol was much higher than that of parsley and its flavonol constituents, it could not significantly change oxidative stress biomarkers. These features of parsley and its flavonols make them as a possible alternative for allopurinol, or at least in combination therapy to minimize the side effects of allopurinol to treat hyperuricemia and oxidative stress diseases.

  15. Flavonóides em seleções de acerola (Malpighia sp l.. 1- Teor de antocianinas e flavonóis totais Flavonoids in acerola (Malpighia sp L. selections. 1- Anthocyanins and flavonols content

    Directory of Open Access Journals (Sweden)

    Vera Lúcia Arroxelas Galvão de Lima

    2000-12-01

    Full Text Available Os flavonóides englobam classes de pigmentos naturais encontrados com freqüência nos vegetais. As antocianinas e os flavonóis são compostos que pertencem ao grupo dos flavonóides e são responsáveis pela coloração que varia de vermelho vivo à violeta e de branco à amarelo claro, respectivamente. A cor vermelha da acerola é decorrente da presença de antocianinas. Entretanto, a propagaç ão da aceloreira por sementes tem gerado frutos com coloração que varia de amarelo a vermelho púrpura. Dessa forma, há o interesse em difundir plantas com produção de frutos com coloração vermelho. Este trabalho teve como objetivo determinar o teor de antocianinas e flavonóis totais nas seleções de acerola - Barbados, Coopama, Flor Branca, Inada, Miró e Okinawa. Os frutos foram colhidos nos meses de março a junho/1999, com coloração vermelha uniforme, e analisados quanto aos teores de antocianinas e flavonóis totais. As seleções Inada e Barbados apresentaram os mais altos teores desses pigmentos, quando comparados aos das demais seleções, tornando-as agronomicamente interessantes.The flavonoids comprise a class of natural pigments that are frequently found in vegetables. The anthocyanins and flavonols are compounds which belong to the flavonoids group and they are responsible for red to violet and white to light-yellow coloration, respectively. The anthocyanins pigments are responsible for the red colour of the acerola fruit. However, the seed propagation of acerola trees has grown fruits which present colour variation from yellow to dark red. So, there is interest to spread acerola trees with red colour fruits. This paper aimed to determine the content of total anthocyanins and flavonols in selections of acerola - Barbados, Coopama, Flor Branca, Inada, Miró e Okinawa. Fruits were harvested based on homogeneous red colour, between the months of March and June/1999, and analysed with regard to the content of total anthocyanins and

  16. SUMO: regulating the regulator

    Directory of Open Access Journals (Sweden)

    Bossis Guillaume

    2006-06-01

    Full Text Available Abstract Post-translational modifiers of the SUMO (Small Ubiquitin-related Modifier family have emerged as key regulators of protein function and fate. While the past few years have seen an enormous increase in knowledge on SUMO enzymes, substrates, and consequences of modification, regulation of SUMO conjugation is far from being understood. This brief review will provide an overview on recent advances concerning (i the interplay between sumoylation and other post-translational modifications at the level of individual targets and (ii global regulation of SUMO conjugation and deconjugation.

  17. Influence of Light and Temperature on Gene Expression Leading to Accumulation of Specific Flavonol Glycosides and Hydroxycinnamic Acid Derivatives in Kale (Brassica oleracea var. sabellica)

    OpenAIRE

    Neugart, Susanne; Krumbein, Angelika; Zrenner, Rita

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plan...

  18. Influence of light and temperature on gene expression leading to accumulation of specific flavonol glycosides and hydroxycinnamic acid derivatives in kale (Brassica oleracea var. sabellica)

    OpenAIRE

    Susanne eNeugart; Angelika eKrumbein; Rita Maria eZrenner

    2016-01-01

    Light intensity and temperature are very important signals for the regulation of plant growth and development. Plants subjected to less favorable light or temperature conditions often respond with accumulation of secondary metabolites. Some of these metabolites have been identified as bioactive compounds, considered to exert positive effects on human health when consumed regularly. In order to test a typical range of growth parameters for the winter crop Brassica oleracea var. sabellica, plan...

  19. Simultaneous Quantification of Flavonol Glycosides, Terpene Lactones, Biflavones, Proanthocyanidins, and Ginkgolic Acids in Ginkgo biloba Leaves from Fruit Cultivars by Ultrahigh-Performance Liquid Chromatography Coupled with Triple Quadrupole Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Xin Yao

    2013-01-01

    Full Text Available On the basis of liquid chromatography coupled with triple quadrupole mass spectrometry working in multiple reaction monitoring mode, an analytical method has been established to simultaneously determine flavonol glycosides, terpene lactones, biflavones, proanthocyanidins, and ginkgolic acids in Ginkgo biloba leaves. Chromatographic separation was carried out on an Acquity BEH C18 column (100 mm × 2.1 mm, 1.7 μm with gradient elution of acetonitrile and 0.10% formic acid (v/v at a flow rate of 0.4 mL/min, and column temperature 30°C. The developed method was validated in terms of linearity, accuracy, precision, stability, and sensitivity. The optimized method was successfully applied to analyze twenty-two G. biloba leaf samples of fruit cultivars collected from different places in China. Furthermore, hierarchical clustering analysis (HCA was performed to evaluate and classify the samples according to the contents of the twenty-four chemical constituents. All of the results demonstrated that the developed method was useful for the overall evaluation of the quality of G. biloba leaves, and this study was also helpful for the comprehensive utilization and development of G. biloba resources.

  20. The Onion (Allium cepa L.) R2R3-MYB Gene MYB1 Regulates Anthocyanin Biosynthesis.

    Science.gov (United States)

    Schwinn, Kathy E; Ngo, Hanh; Kenel, Fernand; Brummell, David A; Albert, Nick W; McCallum, John A; Pither-Joyce, Meeghan; Crowhurst, Ross N; Eady, Colin; Davies, Kevin M

    2016-01-01

    Bulb color is an important consumer trait for onion (Allium cepa L., Allioideae, Asparagales). The bulbs accumulate a range of flavonoid compounds, including anthocyanins (red), flavonols (pale yellow), and chalcones (bright yellow). Flavonoid regulation is poorly characterized in onion and in other plants belonging to the Asparagales, despite being a major plant order containing many important crop and ornamental species. R2R3-MYB transcription factors associated with the regulation of distinct branches of the flavonoid pathway were isolated from onion. These belonged to sub-groups (SGs) that commonly activate anthocyanin (SG6, MYB1) or flavonol (SG7, MYB29) production, or repress phenylpropanoid/flavonoid synthesis (SG4, MYB4, MYB5). MYB1 was demonstrated to be a positive regulator of anthocyanin biosynthesis by the induction of anthocyanin production in onion tissue when transiently overexpressed and by reduction of pigmentation when transiently repressed via RNAi. Furthermore, ectopic red pigmentation was observed in garlic (Allium sativum L.) plants stably transformed with a construct for co-overexpression of MYB1 and a bHLH partner. MYB1 also was able to complement the acyanic petal phenotype of a defined R2R3-MYB anthocyanin mutant in Antirrhinum majus of the asterid clade of eudicots. The availability of sequence information for flavonoid-related MYBs from onion enabled phylogenetic groupings to be determined across monocotyledonous and dicotyledonous species, including the identification of characteristic amino acid motifs. This analysis suggests that divergent evolution of the R2R3-MYB family has occurred between Poaceae/Orchidaceae and Allioideae species. The DNA sequences identified will be valuable for future analysis of classical flavonoid genetic loci in Allium crops and will assist the breeding of these important crop species.

  1. The Onion (Allium cepa L.) R2R3-MYB Gene MYB1 Regulates Anthocyanin Biosynthesis

    Science.gov (United States)

    Schwinn, Kathy E.; Ngo, Hanh; Kenel, Fernand; Brummell, David A.; Albert, Nick W.; McCallum, John A.; Pither-Joyce, Meeghan; Crowhurst, Ross N.; Eady, Colin; Davies, Kevin M.

    2016-01-01

    Bulb color is an important consumer trait for onion (Allium cepa L., Allioideae, Asparagales). The bulbs accumulate a range of flavonoid compounds, including anthocyanins (red), flavonols (pale yellow), and chalcones (bright yellow). Flavonoid regulation is poorly characterized in onion and in other plants belonging to the Asparagales, despite being a major plant order containing many important crop and ornamental species. R2R3-MYB transcription factors associated with the regulation of distinct branches of the flavonoid pathway were isolated from onion. These belonged to sub-groups (SGs) that commonly activate anthocyanin (SG6, MYB1) or flavonol (SG7, MYB29) production, or repress phenylpropanoid/flavonoid synthesis (SG4, MYB4, MYB5). MYB1 was demonstrated to be a positive regulator of anthocyanin biosynthesis by the induction of anthocyanin production in onion tissue when transiently overexpressed and by reduction of pigmentation when transiently repressed via RNAi. Furthermore, ectopic red pigmentation was observed in garlic (Allium sativum L.) plants stably transformed with a construct for co-overexpression of MYB1 and a bHLH partner. MYB1 also was able to complement the acyanic petal phenotype of a defined R2R3-MYB anthocyanin mutant in Antirrhinum majus of the asterid clade of eudicots. The availability of sequence information for flavonoid-related MYBs from onion enabled phylogenetic groupings to be determined across monocotyledonous and dicotyledonous species, including the identification of characteristic amino acid motifs. This analysis suggests that divergent evolution of the R2R3-MYB family has occurred between Poaceae/Orchidaceae and Allioideae species. The DNA sequences identified will be valuable for future analysis of classical flavonoid genetic loci in Allium crops and will assist the breeding of these important crop species. PMID:28018399

  2. Light-induced Variation in Phenolic Compounds in Cabernet Sauvignon Grapes (Vitis vinifera L.) Involves Extensive Transcriptome Reprogramming of Biosynthetic Enzymes, Transcription Factors, and Phytohormonal Regulators

    Science.gov (United States)

    Sun, Run-Ze; Cheng, Guo; Li, Qiang; He, Yan-Nan; Wang, Yu; Lan, Yi-Bin; Li, Si-Yu; Zhu, Yan-Rong; Song, Wen-Feng; Zhang, Xue; Cui, Xiao-Di; Chen, Wu; Wang, Jun

    2017-01-01

    Light environments have long been known to influence grape (Vitis vinifera L.) berry development and biosynthesis of phenolic compounds, and ultimately affect wine quality. Here, the accumulation and compositional changes of hydroxycinnamic acids (HCAs) and flavonoids, as well as global gene expression were analyzed in Cabernet Sauvignon grape berries under sunlight exposure treatments at different phenological stages. Sunlight exposure did not consistently affect the accumulation of berry skin flavan-3-ol or anthocyanin among different seasons due to climatic variations, but increased HCA content significantly at véraison and harvest, and enhanced flavonol accumulation dramatically with its timing and severity degree trend. As in sunlight exposed berries, a highly significant correlation was observed between the expression of genes coding phenylalanine ammonia-lyase, 4-coumarate: CoA ligase, flavanone 3-hydroxylase and flavonol synthase family members and corresponding metabolite accumulation in the phenolic biosynthesis pathway, which may positively or negatively be regulated by MYB, bHLH, WRKY, AP2/EREBP, C2C2, NAC, and C2H2 transcription factors (TFs). Furthermore, some candidate genes required for auxin, ethylene and abscisic acid signal transductions were also identified which are probably involved in berry development and flavonoid biosynthesis in response to enhanced sunlight irradiation. Taken together, this study provides a valuable overview of the light-induced phenolic metabolism and transcriptome changes, especially the dynamic responses of TFs and signaling components of phytohormones, and contributes to the further understanding of sunlight-responsive phenolic biosynthesis regulation in grape berries. PMID:28469625

  3. Market, Regulation, Market, Regulation

    DEFF Research Database (Denmark)

    Frankel, Christian; Galland, Jean-Pierre

    2015-01-01

    This paper focuses on the European Regulatory system which was settled both for opening the Single Market for products and ensuring the consumers' safety. It claims that the New Approach and Standardization, and the Global Approach to conformity assessment, which suppressed the last technical...... barriers to trade in Europe, realized the free movement of products by organizing progressively several orders of markets and regulation. Based on historical and institutional documents, on technical publications, and on interviews, this article relates how the European Commission and the Member States had...... alternatively recourse to markets and to regulations, at the three main levels of the New Approach Directives implementation. The article focuses also more specifically on the Medical Devices sector, not only because this New Approach sector has long been controversial in Europe, and has recently been concerned...

  4. Market, Regulation, Market, Regulation

    DEFF Research Database (Denmark)

    Frankel, Christian; Galland, Jean-Pierre

    2015-01-01

    This paper focuses on the European Regulatory system which was settled both for opening the Single Market for products and ensuring the consumers' safety. It claims that the New Approach and Standardization, and the Global Approach to conformity assessment, which suppressed the last technical...... barriers to trade in Europe, realized the free movement of products by organizing progressively several orders of markets and regulation. Based on historical and institutional documents, on technical publications, and on interviews, this article relates how the European Commission and the Member States had...... alternatively recourse to markets and to regulations, at the three main levels of the New Approach Directives implementation. The article focuses also more specifically on the Medical Devices sector, not only because this New Approach sector has long been controversial in Europe, and has recently been concerned...

  5. Impact of Flavonols on Cardiometabolic Biomarkers:  A Meta‐Analysis of Randomized Controlled Human  Trials to Explore the Role of Inter‐Individual  Variability

    Directory of Open Access Journals (Sweden)

    Regina Menezes

    2017-02-01

    Full Text Available Several  epidemiological  studies  have  linked  flavonols  with  decreased  risk  of  cardiovascular  disease  (CVD.  However,  some  heterogeneity  in  the  individual  physiological  responses to the consumption of these compounds has been identified. This meta‐analysis aimed to  study the effect of flavonol supplementation on biomarkers of CVD risk such as, blood lipids, blood  pressure and plasma glucose, as well as factors affecting their inter‐individual variability. Data from  18 human randomized controlled trials were pooled and the effect was estimated using fixed or  random effects meta‐analysis model and reported as difference in means (DM. Variability in the  response of blood lipids to supplementation with flavonols was assessed by stratifying various  population subgroups: age, sex, country, and health status. Results showed significant reductions  in total cholesterol (DM = −0.10 mmol/L; 95% CI: −0.20, −0.01, LDL cholesterol (DM = −0.14 mmol/L;  Nutrients 2017, 9, 117  2 of 21  95% CI: −0.21, 0.07, and triacylglycerol (DM = −0.10 mmol/L; 95% CI: −0.18, 0.03, and a significant  increase in HDL cholesterol (DM = 0.05 mmol/L; 95% CI: 0.02, 0.07. A significant reduction was also  observed in fasting plasma glucose (DM = −0.18 mmol/L; 95%CI: −0.29, −0.08, and in blood pressure  (SBP: DM = −4.84 mmHg; 95% CI: −5.64, −4.04; DBP: DM = −3.32 mmHg; 95% CI: -4.09, -2.55.  Subgroup analysis showed a more pronounced effect of flavonol intake in participants from Asian  countries and in participants with diagnosed disease or dyslipidemia, compared to healthy and  normal baseline values. In conclusion, flavonol consumption improved biomarkers of CVD risk,  however, country of

  6. Antioxidant flavonol glycosides from Schinus molle.

    Science.gov (United States)

    Marzouk, Mohamed S; Moharram, Fatma A; Haggag, Eman G; Ibrahim, Magda T; Badary, Osama A

    2006-03-01

    Chromatographic separation of aqueous MeOH extract of the leaves of Schinus molle L. has yielded two new acylated quercetin glycosides, named isoquercitrin 6''-O-p-hydroxybenzoate (12) and 2''-O-alpha-L-rhamnopyranosyl-hyperin 6''-O-gallate (13), together with 12 known polyphenolic metabolites for the first time from this species, namely gallic acid (1), methyl gallate (2), chlorogenic acid (3), 2''-alpha-L-rhamnopyranosyl-hyperin (4), quercetin 3-O-beta-D-neohesperidoside (5), miquelianin (6), quercetin 3-O-beta-D-galacturonopyranoside (7), isoquercitrin (8), hyperin (9), isoquercitrin 6''-gallate (10), hyperin 6''-O-gallate (11) and (+)-catechin (14). Their structures were established on the basis of chromatographic properties, chemical, spectroscopic (UV, 1H, 13C NMR) and ESI-MS (positive and negative modes) analyses. Compounds 4-9 and 11 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical and superoxide anion generations with the highest activities shown by 6 and 7 in comparison with that of quercetin as a positive control in vitro.

  7. Regulating Transplants

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Legislation to determine brain death is viewed as essential in controlling the organ transplant industry Organ transplant represents a very sensitive and complicated issue. Experts say the temporary administrative regulations recently promulgated by the Central Government are an important step, but relevant laws and regulations must follow. Among these, the

  8. Determination of flavonol glycosides in tea samples by ultra-high performance liquid chromatography-photodiode array detection-tandem mass spectrometry%超高效液相色谱-二极管阵列检测-串联质谱法测定茶叶中15种黄酮醇糖苷类化合物

    Institute of Scientific and Technical Information of China (English)

    王智聪; 沙跃兵; 余笑波; 梁月荣

    2015-01-01

    采用ACQUITY UPLC HSS T3色谱柱,以含0�1%( v/v)甲酸的乙腈⁃水为流动相,梯度洗脱,建立了超高效液相色谱⁃二极管阵列检测⁃串联质谱( UPLC⁃PDA⁃MS/MS)联用技术测定茶叶中黄酮醇糖苷类化合物的方法。结合色谱保留时间、紫外光谱、一级和二级质谱参数等信息,在绿茶和红茶中共识别了15种黄酮醇糖苷类化合物,包括3种杨梅素糖苷、6种槲皮素糖苷和6种山柰素糖苷类化合物。定量分析中采用串联四极杆质谱检测,以槲皮素⁃3⁃葡萄糖⁃鼠李糖二糖糖苷( Q⁃GRh)为标准品,其他黄酮醇糖苷进行相对定量。结果表明,绿茶和红茶中黄酮醇糖苷类化合物的含量和分布差异显著,绿茶中的黄酮醇糖苷总量是红茶的1�7倍,绿茶中的黄酮醇糖苷主要以杨梅素⁃3⁃半乳糖糖苷( M⁃Ga)、杨梅素⁃3⁃葡萄糖糖苷( M⁃G)、槲皮素⁃3⁃葡萄糖⁃鼠李糖⁃葡萄糖三糖糖苷( Q⁃GaRhG)、槲皮素⁃3⁃半乳糖⁃鼠李糖⁃葡萄糖三糖糖苷( Q⁃GRhG)、山柰素⁃3⁃半乳糖⁃鼠李糖⁃葡萄糖三糖糖苷( K⁃GaRhG)和山柰素⁃3⁃葡萄糖⁃鼠李糖⁃葡萄糖三糖糖苷( K⁃GRhG)为主,而红茶中主要以Q⁃GRh、槲皮素⁃3⁃葡萄糖糖苷( Q⁃G)、山柰素⁃3⁃葡萄糖⁃鼠李糖二糖糖苷( K⁃GRh)和山柰素⁃3⁃半乳糖糖苷( K⁃Ga)为主。本方法简单快速,准确性好,可用于茶叶中黄酮醇糖苷类化合物的分析。%An ultra⁃high performance liquid chromatography⁃photodiode array detection⁃tandem mass spectrometry ( UPLC⁃PDA⁃MS/MS) method was developed for the determination of flavo⁃nol glycosides in tea samples. The chromatographic separation was performed on an UPLC HSS T3 column by gradient elution with the mobile phases of acetonitrile and water both containing 0�1%( v/v) formic acid. A total of 15 flavonol

  9. Effect of flavonol on reduction of acrylamide in Maillard reaction and its correlation with antioxidant capacity%黄酮醇抑制丙烯酰胺在美拉德反应中的形成及与抗氧化间的相关性

    Institute of Scientific and Technical Information of China (English)

    程军; 任一平; 张英; 章宇

    2013-01-01

    genetic and reproductive toxicities as well as mutagenic and carcinogenic properties . Therefore , it is necessary to find effective additive agents to reduce the formation of acrylamide in Maillard reaction .We investigated the effects of flavonols on the reduction of acrylamide in an equimolar asparagine‐glucose Maillard reaction system using potato matrix and microwave heating . To investigate the dose‐response effect , six different levels of flavonols were added into the self‐prepared Maillard reaction system and different levels of acrylamide were generated and observed . Meanwhile , the correlation between the inhibitory rate of acrylamide affected by flavonols and the change of Trolox equivalent antioxidant capacity ( ΔTEAC ) in Maillard reaction products was also evaluated . Acrylamide levels in Maillard reaction products were determined by ultra‐high performance liquid chromatography coupled with tandem mass spectrometry ( U HPLC‐MS/MS ) and quantified with multiple reaction monitoring ( MRM ) mode after the pretreatment of final products . ΔTEAC values were simultaneously measured by three representative antioxidant evaluation methods , i .e . DPPH ( 1 ,1‐diphenyl‐2‐picrylhydrazyl) , ABTS ( 2 ,2‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid) and FRAP ( ferric reducing ability of plasma) . The results indicated a non‐linear relationship between addition levels of flavonols and inhibitory rate of acrylamide . The optimal addition level of all six flavonols , i .e . kaempferol , kaempferol‐3‐o‐glucoside , quercetin , quercetin‐3‐o‐glucoside , myricetin and rutin was 1 × 10-9 mol/L , which exerted their maximal inhibitory effect against the generation of acrylamide . The inhibitory rate ranged from 48 .9% to 69 .3% when different types of flavonols were used at the optimal addition level . Taking ΔTEAC as the antioxidant measurement index , the correlation coefficients between ΔTEAC determined by three different

  10. NORM regulations

    Energy Technology Data Exchange (ETDEWEB)

    Gray, P. [ed.

    1997-02-01

    The author reviews the question of regulation for naturally occuring radioactive material (NORM), and the factors that have made this a more prominent concern today. Past practices have been very relaxed, and have often involved very poor records, the involvment of contractors, and the disposition of contaminated equipment back into commercial service. The rationale behind the establishment of regulations is to provide worker protection, to exempt low risk materials, to aid in scrap recycling, to provide direction for remediation and to examine disposal options. The author reviews existing regulations at federal and state levels, impending legislation, and touches on the issue of site remediation and potential liabilities affecting the release of sites contaminated by NORM.

  11. Quercetin induces apoptosis by activating caspase-3 and regulating Bcl-2 and cyclooxygenase-2 pathways in human HL-60 cells.

    Science.gov (United States)

    Niu, Guomin; Yin, Songmei; Xie, Shuangfeng; Li, Yiqing; Nie, Danian; Ma, Liping; Wang, Xiuju; Wu, Yudan

    2011-01-01

    Quercetin is one of the naturally occurring dietary flavonol compounds. It is present abundantly in plants and has chemopreventive and anticancer effects. To investigate its anticancer mechanism, we examined the activity of quercetin against acute leukemia cell line, HL-60. Our results showed that quercetin inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. Furthermore, quercetin down-regulated the expression of anti-apoptosis protein Bcl-2 and up-regulated the expression of pro-apoptosis protein Bax. Caspase-3 was also activated by quercetin, which started a caspase-3-depended mitochodrial pathway to induce apoptosis. It was also found that quercetin inhibited the expression of the cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein. Taken together, these findings suggested that quercetin induces apoptosis in a caspase-3-dependent pathway by inhibiting Cox-2 expression and regulates the expression of downstream apoptotic components, including Bcl-2 and Bax. Quercetin can be a potent and promising medicine which might be safely used in leukemia therapy.

  12. Quercetin induces apoptosis by activating caspase-3 and regulating Bcl-2 and cyclooxygenase-2 pathways in human HL-60 cells

    Institute of Scientific and Technical Information of China (English)

    Guomin Niu; Songmei Yin; Shuangfeng Xie; Yiqing Li; Danian Nie; Liping Ma; Xiuju Wang; Yudan Wu

    2011-01-01

    Quercetin is one of the naturally occurring dietary flavo-nol compounds. It is present abundantly in plants and has chemopreventive and anticancer effects. To investigate its anticancer mechanism, we examined the activity of quercetin against acute leukemia cell line, HL-60. Our results showed that quercetin inhibited cell proliferation and induced apoptosis in a time- and dose-dependent manner. Furthermore, quercetin down-regulated the expression of anti-apoptosis protein Bcl-2 and up-regulated the expression of pro-apoptosis protein Bax. Caspase-3 was also activated by quercetin, which started a caspase-3-depended mitochodrial pathway to induce apoptosis. It was also found that quercetin inhibited the expression of the cycloocygenase-2 (Cox-2) mRNA and Cox-2 protein. Taken together, these findings suggested that quercetin induces apoptosis in a caspase-3-dependent pathway by inhibiting Cox-2 expression and regulates the expression of downstream apoptotic components, including Bcl-2 and Bax. Quercetin can be a potent and promising medicine which might be safely used in leukemia therapy.

  13. Fisetin regulates astrocyte migration and proliferation in vitro.

    Science.gov (United States)

    Wang, Nan; Yao, Fang; Li, Ke; Zhang, Lanlan; Yin, Guo; Du, Mingjun; Wu, Bingyi

    2017-04-01

    Fisetin (3,3',4',7-tetrahydroxyflavone) is a plant flavonol found in fruits and vegetables that has been reported to inhibit migration and proliferation in several types of cancer. Reactive astrogliosis involves astrocyte migration and proliferation, and contributes to the formation of glial scars in central nervous system (CNS) disorders. However, the effect of fisetin on the migration and proliferation of astrocytes remains unclear. In this study, we found that fisetin inhibited astrocyte migration in a scratch-wound assay and diminished the phosphorylation of focal adhesion kinase (FAK; Tyr576/577 and paxillin (Tyr118). It also suppressed cell proliferation, as indicated by the decreased number of 5-ethynyl-2'-deoxyuridine (EdU)-positive cells, induced cell cycle arrest in the G1 phase, reduced the percentage of cells in the G2 and S phase (as measured by flow cytometry), and decreased cyclin D1 expression, but had no effect on apoptosis. Fisetin also decreased the phosphorylation levels of Akt and extracellular signal-regulated kinase (Erk)1/2, but had no effect on the phosphorylation of p38 mitogen-activated protein kinase (MAPK). These results indicate that fisetin inhibits aggressive cell phenotypes by suppressing cell migration and proliferation via the Akt/Erk signaling pathway. Fisetin may thus have potential for use as a therapeutic strategy targeting reactive astrocytes, which may lead to the inhibition of glial scar formation in vitro.

  14. Effects of Fertilier and Drought Stress on Growth as well as Flavonol Glycosides and Terpene Lactone Content of Ginkgo Biloba Seedlings%施肥与干旱胁迫对银杏生长及黄酮苷和萜类内酯含量的影响

    Institute of Scientific and Technical Information of China (English)

    冷平生; 李月华; 苏淑钗; 王沙生; 蒋湘宁

    2001-01-01

    Effects of VAM fungi(Glomus mosseae and G versiforme)、N、P fertilizer and drought stress on the growth as well as flavonol glycosides and terpene lactone content of Ginkgo biloba seedlings were measured,experimental results showed that VAM fungi、N、P fertilizer obviously increased uptake of N、P elements,improved growth,enhanced terpene lactone content,drought stress decreased leaf water potencial and terpene lactone content of ginkgo biloba seedlings,those negative effects might be compensated by infection of host plants with both VAM fungi in some extent.Biosynthesis and metabolize of terpene lactones of ginkgo bilobamight be close relative to growth status of Ginkgo biloba seedlings.VAM fung;,N、P fertilizer drought stress had little effect on flavonol glycoside content of Ginkgo biloba.%对银杏实生苗接种VAM真菌,叶面喷施N、P肥及干旱胁迫处理,测定银杏生长及黄酮苷和萜类内酯含量的变化,试验结果表明:增施N、P肥能显著改善银杏植株N、P供应,增加银杏苗叶量和干重,显著提高银杏叶萜类内酯含量,而对银杏黄酮苷含量影响较小;干旱胁迫降低银杏叶水势和萜类内酯含量,对银杏黄酮苷含量没有影响,接种VAM真菌能减轻干旱胁迫的负影响,显著提高银杏萜类内酯含量。银杏萜类内酯的生物合成代谢与银杏生长状况密切相关。

  15. Genome-wide Expression Analysis and Metabolite Profiling Elucidate Transcriptional Regulation of Flavonoid Biosynthesis and Modulation under Abiotic Stresses in Banana.

    Science.gov (United States)

    Pandey, Ashutosh; Alok, Anshu; Lakhwani, Deepika; Singh, Jagdeep; Asif, Mehar H; Trivedi, Prabodh K

    2016-08-19

    Flavonoid biosynthesis is largely regulated at the transcriptional level due to the modulated expression of genes related to the phenylpropanoid pathway in plants. Although accumulation of different flavonoids has been reported in banana, a staple fruit crop, no detailed information is available on regulation of the biosynthesis in this important plant. We carried out genome-wide analysis of banana (Musa acuminata, AAA genome) and identified 28 genes belonging to 9 gene families associated with flavonoid biosynthesis. Expression analysis suggested spatial and temporal regulation of the identified genes in different tissues of banana. Analysis revealed enhanced expression of genes related to flavonol and proanthocyanidin (PA) biosynthesis in peel and pulp at the early developmental stages of fruit. Genes involved in anthocyanin biosynthesis were highly expressed during banana fruit ripening. In general, higher accumulation of metabolites was observed in the peel as compared to pulp tissue. A correlation between expression of genes and metabolite content was observed at the early stage of fruit development. Furthermore, this study also suggests regulation of flavonoid biosynthesis, at transcriptional level, under light and dark exposures as well as methyl jasmonate (MJ) treatment in banana.

  16. Genome-wide Expression Analysis and Metabolite Profiling Elucidate Transcriptional Regulation of Flavonoid Biosynthesis and Modulation under Abiotic Stresses in Banana

    Science.gov (United States)

    Pandey, Ashutosh; Alok, Anshu; Lakhwani, Deepika; Singh, Jagdeep; Asif, Mehar H.; Trivedi, Prabodh K.

    2016-01-01

    Flavonoid biosynthesis is largely regulated at the transcriptional level due to the modulated expression of genes related to the phenylpropanoid pathway in plants. Although accumulation of different flavonoids has been reported in banana, a staple fruit crop, no detailed information is available on regulation of the biosynthesis in this important plant. We carried out genome-wide analysis of banana (Musa acuminata, AAA genome) and identified 28 genes belonging to 9 gene families associated with flavonoid biosynthesis. Expression analysis suggested spatial and temporal regulation of the identified genes in different tissues of banana. Analysis revealed enhanced expression of genes related to flavonol and proanthocyanidin (PA) biosynthesis in peel and pulp at the early developmental stages of fruit. Genes involved in anthocyanin biosynthesis were highly expressed during banana fruit ripening. In general, higher accumulation of metabolites was observed in the peel as compared to pulp tissue. A correlation between expression of genes and metabolite content was observed at the early stage of fruit development. Furthermore, this study also suggests regulation of flavonoid biosynthesis, at transcriptional level, under light and dark exposures as well as methyl jasmonate (MJ) treatment in banana. PMID:27539368

  17. Effect of metabolic regulators on aluminium uptake and toxicity in Matricaria chamomilla plants.

    Science.gov (United States)

    Kováčik, Jozef; Stork, František; Klejdus, Bořivoj; Grúz, Jiři; Hedbavny, Josef

    2012-05-01

    Phenolic metabolism of Al-exposed Matricaria chamomilla plants was modulated with four regulators: 2-aminoindane-2-phosphonic acid (AIP), salicylic acid (SA), sodium nitroprusside (SNP) and dithiothreitol (DTT). Physiological parameters (tissue water content, soluble proteins, reducing sugars, K+ content), root lignin content and free amino acids (increase in root proline and alanine) were the most affected in SA + Al variant, indicating negative impact of SA on Al-induced changes. SNP showed the least visible impact, suggesting protective effect of nitric oxide. Complex comparison between Al alone and combined treatments revealed that SA and DTT stimulated increase in shoot phenolic acids (mainly vanillic acid), sum of flavonols and soluble phenols but decreased the levels of coumarin-related compounds (Z- and E-2-β-D-glucopyranosyloxy-4-methoxycinnamic acids), leading to elevation of shoot Al. Positive correlation between phenolic acids (mainly ferulic and chlorogenic acids), soluble phenols and total Al was found in the roots of SA and DTT variants. These events were not observed in AIP and SNP treatments. These data, to our knowledge for the first time, exactly confirm that phenolic metabolites may affect shoot Al uptake and this relation is rather positive in terms of simple phenols (and negative in terms of coumarin-related compounds).

  18. Kaempferol ameliorates symptoms of metabolic syndrome by regulating activities of liver X receptor-β.

    Science.gov (United States)

    Hoang, Minh-Hien; Jia, Yaoyao; Mok, Boram; Jun, Hee-jin; Hwang, Kwang-Yeon; Lee, Sung-Joon

    2015-08-01

    Kaempferol is a dietary flavonol previously shown to regulate cellular lipid and glucose metabolism. However, its molecular mechanisms of action and target proteins have remained elusive, probably due to the involvement of multiple proteins. This study investigated the molecular targets of kaempferol. Ligand binding of kaempferol to liver X receptors (LXRs) was quantified by time-resolved fluorescence resonance energy transfer and surface plasmon resonance analyses. Kaempferol directly binds to and induces the transactivation of LXRs, with stronger specificity for the β-subtype (EC50 = 0.33 μM). The oral administration of kaempferol in apolipoprotein-E-deficient mice (150 mg/day/kg body weight) significantly reduced plasma glucose and increased high-density lipoprotein cholesterol levels and insulin sensitivity compared with the vehicle-fed control. Kaempferol also reduced plasma triglyceride concentrations and did not cause liver steatosis, a common side effect of potent LXR activation. In immunoblotting analysis, kaempferol reduced the nuclear accumulation of sterol regulatory element-binding protein-1 (SREBP-1). Our results show that the suppression of SREBP-1 activity and the selectivity for LXR-β over LXR-α by kaempferol contribute to the reductions of plasma and hepatic triglyceride concentrations in mice fed kaempferol. They also suggest that kaempferol activates LXR-β and suppresses SREBP-1 to enhance symptoms in metabolic syndrome.

  19. Synthesis and regulation of chlorogenic acid in potato: Rerouting phenylpropanoid flux in HQT-silenced lines.

    Science.gov (United States)

    Payyavula, Raja S; Shakya, Roshani; Sengoda, Venkatesan G; Munyaneza, Joseph E; Swamy, Prashant; Navarre, Duroy A

    2015-05-01

    Chlorogenic acid (CGA) is the major phenolic sink in potato tubers and can constitute over 90% of total phenylpropanoids. The regulation of CGA biosynthesis in potato and the role of the CGA biosynthetic gene hydroxycinnamoyl CoA:quinate hydroxycinnamoyl transferase (HQT) was characterized. A sucrose induced accumulation of CGA correlated with the increased expression of phenylalanine ammonia-lyase (PAL) rather than HQT. Transient expression of the potato MYB transcription factor StAN1 (anthocyanin 1) in tobacco increased CGA. RNAi suppression of HQT resulted in over a 90% reduction in CGA and resulted in early flowering. The reduction in total phenolics and antioxidant capacity was less than the reduction in CGA, suggesting flux was rerouted into other phenylpropanoids. Network analysis showed distinct patterns in different organs, with anthocyanins and phenolic acids showing negative correlations in leaves and flowers and positive in tubers. Some flavonols increased in flowers, but not in leaves or tubers. Anthocyanins increased in flowers and showed a trend to increase in leaves, but not tubers. HQT suppression increased biosynthesis of caffeoyl polyamines, some of which are not previously reported in potato. Decreased PAL expression and enzyme activity was observed in HQT suppressed lines, suggesting the existence of a regulatory loop between CGA and PAL. Electrophysiology detected no effect of CGA suppression on potato psyllid feeding. Collectively, this research showed that CGA in potatoes is synthesized through HQT and HQT suppression altered phenotype and redirected phenylpropanoid flux.

  20. Bioactive constituents from chinese natural medicines. XXIV. Hypoglycemic effects of Sinocrassula indica in sugar-loaded rats and genetically diabetic KK-A(y) mice and structures of new acylated flavonol glycosides, sinocrassosides A(1), A(2), B(1), and B(2).

    Science.gov (United States)

    Yoshikawa, Masayuki; Wang, Tao; Morikawa, Toshio; Xie, Haihui; Matsuda, Hisashi

    2007-09-01

    The methanolic extract from the whole plant of Sinocrassula indica (Crassulaceae) was found to inhibit the increase in serum glucose levels in oral administration of sucrose and glucose in rats at a dose of 250 mg/kg (p.o.). However, the extract did not inhibit the increase in serum glucose levels after intraperitoneal administration of glucose in these animals but did partly inhibit the gastric emptying. On the other hand, this extract significantly inhibited the increase in serum glucose levels after administration for 2 weeks in KK-A(y) mice, a genetically type II diabetic mice, at a dose of 250 mg/kg/d (p.o.) without significant changes of the weights of body, liver, and visceral fat. From the extract, four new acylated flavonol glycosides, sinocrassosides A(1), A(2), B(1), and B(2), were isolated together with 11 flavonoids and 2 megastigmanes. The absolute stereostructures of the four new compounds were elucidated on the basis of chemical and physicochemical evidence.

  1. Microwave-Assisted Method for Simultaneous Extraction and Hydrolysis for Determination of Flavonol Glycosides in Ginkgo Foliage Using Brönsted Acidic Ionic-Liquid [HO3S(CH24mim]HSO4 Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Yuangang Zu

    2012-07-01

    Full Text Available The Brönsted acidic ionic-liquid [HO3S(CH24mim] HSO4, a novel dual catalyst–solvent, has been successfully applied in simultaneous microwave-assisted extraction and hydrolysis for the determination of flavonol glycosides in Ginkgo foliage. The parameters, namely the [HO3S(CH24mim]HSO4 concentration, microwave-irradiation power, microwave-irradiation time, and solid–liquid ratio, were optimized. The optimum conditions were: an amount of 1.5 M [HO3S(CH24mim]HSO4, a microwave-irradiation power of 120 W, an irradiation time of 15 min, and a solid–liquid ratio of 1:30 g/mL. Compared with traditional methods the proposed approach demonstrates higher efficiency in a shorter operating time, and is an efficient, rapid, and simple sample preparation method.

  2. Fisetin regulates obesity by targeting mTORC1 signaling.

    Science.gov (United States)

    Jung, Chang Hwa; Kim, Heemun; Ahn, Jiyun; Jeon, Tae-Il; Lee, Dae-Hee; Ha, Tae-Youl

    2013-08-01

    Fisetin, a flavonol present in vegetables and fruits, possesses antioxidative and anti-inflammatory properties. In this study, we have demonstrated that fisetin prevents diet-induced obesity through regulation of the signaling of mammalian target of rapamycin complex 1 (mTORC1), a central mediator of cellular growth, cellular proliferation and lipid biosynthesis. To evaluate whether fisetin regulates mTORC1 signaling, we investigated the phosphorylation and kinase activity of the 70-kDa ribosomal protein S6 kinase 1 (S6K1) and mTORC1 in 3T3-L1 preadipocytes. Fisetin treatment of preadipocytes reduced the phosphorylation of S6K1 and mTORC1 in a time- and concentration-dependent manner. To further our understanding of how fisetin negatively regulates mTORC1 signaling, we analyzed the phosphorylation of S6K1, mTOR and Akt in fisetin-treated TSC2-knockdown cells. The results suggested that fisetin treatment inhibits mTORC1 activity in an Akt-dependent manner. Recent studies have shown that adipocyte differentiation is dependent on mTORC1 activity. Fisetin treatment inhibited adipocyte differentiation, consistent with the negative effect of fisetin on mTOR. The inhibitory effect of fisetin on adipogenesis is dependent of mTOR activity, suggesting that fisetin inhibits adipogenesis and the accumulation of intracellular triglycerides during adipocyte differentiation by targeting mTORC1 signaling. Fisetin supplementation in mice fed a high-fat diet (HFD) significantly attenuated HFD-induced increases in body weight and white adipose tissue. We also observed that fisetin efficiently suppressed the phosphorylation of Akt, S6K1 and mTORC1 in adipose tissue. Collectively, these results suggest that inhibition of mTORC1 signaling by fisetin prevents adipocyte differentiation of 3T3-L1 preadipocytes and obesity in HFD-fed mice. Therefore, fisetin may be a useful phytochemical agent for attenuating diet-induced obesity. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Antioxidant capacity changes and phenolic profile of Echinacea purpurea, nettle (Urtica dioica L.), and dandelion (Taraxacum officinale) after application of polyamine and phenolic biosynthesis regulators.

    Science.gov (United States)

    Hudec, Jozef; Burdová, Mária; Kobida, L'ubomír; Komora, Ladislav; Macho, Vendelín; Kogan, Grigorij; Turianica, Ivan; Kochanová, Radka; Lozek, Otto; Habán, Miroslav; Chlebo, Peter

    2007-07-11

    The changes of the antioxidant (AOA) and antiradical activities (ARA) and the total contents of phenolics, anthocyanins, flavonols, and hydroxybenzoic acid in roots and different aerial sections of Echinacea purpurea, nettle, and dandelion, after treatment with ornithine decarboxylase inhibitor, a polyamine inhibitor (O-phosphoethanolamine, KF), and a phenol biosynthesis stimulator (carboxymethyl chitin glucan, CCHG) were analyzed spectrophotometrically; hydroxycinnamic acids content was analyzed by RP-HPLC with UV detection. Both regulators increased the AOA measured as inhibition of peroxidation (IP) in all herb sections, with the exception of Echinacea stems after treatment with KF. In root tissues IP was dramatically elevated mainly after CCHG application: 8.5-fold in Echinacea, 4.14-fold in nettle, and 2.08-fold in dandelion. ARA decrease of Echinacea leaves treated with regulators was in direct relation only with cichoric acid and caftaric acid contents. Both regulators uphold the formation of cinnamic acid conjugates, the most expressive being that of cichoric acid after treatment with CCHG in Echinacea roots from 2.71 to 20.92 mg g(-1). There was a strong relationship between increase of the total phenolics in all sections of Echinacea, as well as in the studied sections of dandelion, and the anthocyanin content.

  4. RP-HPLC法测定银杏叶提取物类脂质体中黄酮和萜类内酯含量的优化方法%Quantitative Determination of Flavonol Glycosides and Terpene Lactones from Ginkgo Leaf Extract Noisome

    Institute of Scientific and Technical Information of China (English)

    崔大明; 金叶; 周毓麟; 李玉环; 郭璇; 滕利荣; 张炜煜

    2013-01-01

    The aim of this study was to develop a simple and accurate isocratic RP-HPLC analytical method to qualify and quantify three flavonol glycosides (Quercetin,Kaempferol and Isorhamnetin) and four terpene lactones (Ginkgolide A,Ginkgolide B,Ginkgolide C and Bilobalide) of ginkgo leaf extract.The contents of flavonoid glycosides and terpene lactones from EGBN were measured by dialysis method.And the saturation solubility of flavonoid glycosides was also measured with this HPLC method.The condition of HPLC method for flavonol glycosides is:column:Agilent HC-C18 (4.6 mm× 250.0 mm,5 μm) ; mobile phase:ACN-0.4% phosphoric acid (28∶72,v/v).The drug elution was performed at 40 ℃ at a flow rate of 1.0 mL/min and detected at the wavelength of 360 nm.And the condition of HPLC method for terpene lactones is:column:Agilent HC-C18 (250.0 mm × 4.6 mm,5μn) ; mobile phase:Methonal-THF-Water (46∶7∶47,v/v/v).The flow rate was kept at 0.8 mL/min.The temperature of NEB and EVA was performed at 60 ℃ and 105 ℃,respectively.The HPLC methods for flavonol glycosides and terpene lactones were shown to be linear,precise,sensitive,selective and accurate.And the contents of flavonoid glycosides and terpene lactones from EGBN can be measured by dialysis method.%建立反相高效液相色谱法(RP-HPLC),测定银杏叶提取物类脂质体(EGBN)中银杏3种黄酮化合物(槲皮素、山奈素、异鼠李素)和4种萜类内酯(银杏内酯A、银杏内酯B、银杏内酯C、白果内酯)的含量,及银杏总黄酮醇苷的饱和溶解度.采用透析法提取出EGBN中的银杏黄酮.黄酮应用Agilent HC-C18色谱柱(4.6 mm× 250.0 mm,5μm),以V(乙腈)∶V(0.4%磷酸)=28∶72为流动相,流速1.0 mL/min,检测波长360nm,柱温40℃.萜类内酯应用Agilent HC-C18色谱柱(4.6 mm×250.0 mm,5μm),以V(甲醇)∶V(四氢呋喃)∶V(水)=46∶7∶47为流动相,流速0.8 mL/min,NEB温度60℃,EVA温度105℃.结果表明:透析法可以将EGBN中有效成分很好的分

  5. Transcription factors, sucrose, and sucrose metabolic genes interact to regulate potato phenylpropanoid metabolism.

    Science.gov (United States)

    Payyavula, Raja S; Singh, Rajesh K; Navarre, Duroy A

    2013-11-01

    Much remains unknown about how transcription factors and sugars regulate phenylpropanoid metabolism in tuber crops like potato (Solanum tuberosum). Based on phylogeny and protein similarity to known regulators of phenylpropanoid metabolism, 15 transcription factors were selected and their expression was compared in white, yellow, red, and purple genotypes with contrasting phenolic and anthocyanin profiles. Red and purple genotypes had increased phenylalanine ammonia lyase (PAL) enzyme activity, markedly higher levels of phenylpropanoids, and elevated expression of most phenylpropanoid structural genes, including a novel anthocyanin O-methyltransferase. The transcription factors Anthocyanin1 (StAN1), basic Helix Loop Helix1 (StbHLH1), and StWD40 were more strongly expressed in red and purple potatoes. Expression of 12 other transcription factors was not associated with phenylpropanoid content, except for StMYB12B, which showed a negative relationship. Increased expression of AN1, bHLH1, and WD40 was also associated with environmentally mediated increases in tuber phenylpropanoids. Treatment of potato plantlets with sucrose induced hydroxycinnamic acids, flavonols, anthocyanins, structural genes, AN1, bHLH1, WD40, and genes encoding the sucrose-hydrolysing enzymes SUSY1, SUSY4, and INV2. Transient expression of StAN1 in tobacco leaves induced bHLH1, structural genes, SUSY1, SUSY4, and INV1, and increased phenylpropanoid amounts. StAN1 infiltration into tobacco leaves decreased sucrose and glucose concentrations. In silico promoter analysis revealed the presence of MYB and bHLH regulatory elements on sucrolytic gene promoters and sucrose-responsive elements on the AN1 promoter. These findings reveal an interesting dynamic between AN1, sucrose, and sucrose metabolic genes in modulating potato phenylpropanoids.

  6. Combinatorial Gene Regulation Using Auto-Regulation

    Science.gov (United States)

    Hermsen, Rutger; Ursem, Bas; ten Wolde, Pieter Rein

    2010-01-01

    As many as 59% of the transcription factors in Escherichia coli regulate the transcription rate of their own genes. This suggests that auto-regulation has one or more important functions. Here, one possible function is studied. Often the transcription rate of an auto-regulator is also controlled by additional transcription factors. In these cases, the way the expression of the auto-regulator responds to changes in the concentrations of the “input” regulators (the response function) is obviously affected by the auto-regulation. We suggest that, conversely, auto-regulation may be used to optimize this response function. To test this hypothesis, we use an evolutionary algorithm and a chemical–physical model of transcription regulation to design model cis-regulatory constructs with predefined response functions. In these simulations, auto-regulation can evolve if this provides a functional benefit. When selecting for a series of elementary response functions—Boolean logic gates and linear responses—the cis-regulatory regions resulting from the simulations indeed often exploit auto-regulation. Surprisingly, the resulting constructs use auto-activation rather than auto-repression. Several design principles show up repeatedly in the simulation results. They demonstrate how auto-activation can be used to generate sharp, switch-like activation and repression circuits and how linearly decreasing response functions can be obtained. Auto-repression, on the other hand, resulted only when a high response speed or a suppression of intrinsic noise was also selected for. The results suggest that, while auto-repression may primarily be valuable to improve the dynamical properties of regulatory circuits, auto-activation is likely to evolve even when selection acts on the shape of response function only. PMID:20548950

  7. 银杏叶提取物注射液中槲皮素、山柰酚、异鼠李素及总黄酮醇苷的HPLC法测定%Determination of Quercetin,Kaempferol,Isorhamnetin and Their Total Flavonol Glycosides in Ginkgo Biloba Extract Injection by HPLC

    Institute of Scientific and Technical Information of China (English)

    林佳媛; 张鹏; 蔡卫民; 马国

    2012-01-01

    An HPLC method was established for the determination of quercetin, kaempferol, isorhamnetin and their total flavonol glycosides in Ginkgo Biloba extract injection and the quality evaluation of two brands. A Diamonsil C18 column was used with the mobile phase of methanol-0.4% phosphoric acid (55 :45) at the detection wavelength of 360 nm. Quercetin, kaempferol and isorhamnetin in the unhydrolyzed and hydrolyzed Ginkgo Biloba extract injection showed good separation and linearity ranges. The average recoveries of quercetin, kaempferol and isorhamnetin in the unhydrolyzed and hydrolyzed samples were 100.2%, 100.3%, 100.2% with RSDs of 0.64%, 1.14%, 0.40%, and 100.0%, 100.7%, 100.3% with RSDs of 0.79%, 0.98%, 1.00%, respectively.%建立了高效液相色谱法测定银杏叶提取物注射液中的槲皮素、山柰酚、异鼠李素及总黄酮醇苷,评价了注射液的质量.色谱柱为Diamonsil C18柱,流动相为甲醇-0.4%磷酸(55∶45),检测波长360 nm.银杏叶提取物注射液水解前后,其主要组分槲皮素、山柰酚和异鼠李素分离良好,线性范围宽,平均加样回收率水解前分别为100.2%、100.3%和100.2%,RSD分别为0.64%、1.14%和0.40%水解后分别为100.0%、100.7%和100.3%,RSD分别为0.79%、0.98%和1.00%.

  8. Trout Stream Special Regulations

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer shows Minnesota trout streams that have a special regulation as described in the 2006 Minnesota Fishing Regulations. Road crossings were determined using...

  9. Hepcidin: regulation of the master iron regulator

    Science.gov (United States)

    Rishi, Gautam; Wallace, Daniel F.; Subramaniam, V. Nathan

    2015-01-01

    Iron, an essential nutrient, is required for many diverse biological processes. The absence of a defined pathway to excrete excess iron makes it essential for the body to regulate the amount of iron absorbed; a deficiency could lead to iron deficiency and an excess to iron overload and associated disorders such as anaemia and haemochromatosis respectively. This regulation is mediated by the iron-regulatory hormone hepcidin. Hepcidin binds to the only known iron export protein, ferroportin (FPN), inducing its internalization and degradation, thus limiting the amount of iron released into the blood. The major factors that are implicated in hepcidin regulation include iron stores, hypoxia, inflammation and erythropoiesis. The present review summarizes our present knowledge about the molecular mechanisms and signalling pathways contributing to hepcidin regulation by these factors. PMID:26182354

  10. General Theories of Regulation

    NARCIS (Netherlands)

    Hertog, J.A. den

    1999-01-01

    This chapter makes a distinction between three types of theories of regulation: public interest theories, the Chicago theory of regulation and the public choice theories. The Chicago theory is mainly directed at the explanation of economic regulation; public interest theories and public choice theor

  11. Transciptome analysis reveals flavonoid biosynthesis regulation and simple sequence repeats in yam (Dioscorea alata L.) tubers.

    Science.gov (United States)

    Wu, Zhi-Gang; Jiang, Wu; Mantri, Nitin; Bao, Xiao-Qing; Chen, Song-Lin; Tao, Zheng-Ming

    2015-04-30

    Yam (Dioscorea alata L.) is an important tuber crop and purple pigmented elite cultivar has recently become popular because of associated health benefits. Identifying candidate genes responsible for flavonoid biosynthesis pathway (FBP) will facilitate understanding the molecular mechanism of controlling pigment formation in yam tubers. Here, we used Illumina sequencing to characterize the transcriptome of tubers from elite purple-flesh cultivar (DP) and conventional white-flesh cultivar (DW) of yam. In this process, we also designed high quality molecular markers to assist molecular breeding for tuber trait improvement. A total of 125,123 unigenes were identified from the DP and DW cDNA libraries, of which about 49.5% (60,020 unigenes) were annotated by BLASTX analysis using the publicly available protein database. These unigenes were further annotated functionally and subject to biochemical pathway analysis. 511 genes were identified to be more than 2-fold (FDR yam cultivars, of which 288 genes were up-regulated and 223 genes were down-regulated in the DP tubers. Transcriptome analysis detected 61 unigenes encoding multiple well-known enzymes in the FBP. Furthermore, the unigenes encoding chalcone isomerase (CHS), flavanone 3-hydroxylase (F3H), flavonoid 3'-monooxygenase (F3'H), dihydroflavonol 4-reductase (DFR), leucoanthocyanidin dioxygenase (LDOX), and flavonol 3-O-glucosyltransferase (UF3GT) were found to be significantly up-regulated in the DP, implying that these genes were potentially associated with tuber color formation in this elite cultivar. The expression of these genes was further confirmed by qRT-PCR. Finally, 11,793 SSRs were successfully identified with these unigenes and 6,082 SSR markers were developed using Primer 3. This study provides the first comprehensive transcriptomic dataset for yam tubers, which will significantly contribute to genomic research of this and other related species. Some key genes associated with purple-flesh trait were

  12. Flavonol and flavone intakes in US health professionals

    NARCIS (Netherlands)

    Sampson, L.; Rimm, E.; Hollman, P.C.H.; Vries, de J.H.M.; Katan, M.B.

    2002-01-01

    Objective To determine flavonoid content of US foods, mean individual intakes, major food sources, and associations with other nutrients. Subjects US men (n=37,886) and women (n=78,886) who completed a semiquantitative food frequency questionnaire in 1990. Design Men and women completed a questionna

  13. A new flavonol glycoside from Hydrangea macrophylla (Thunb.) Seringe

    Institute of Scientific and Technical Information of China (English)

    Wei

    2010-01-01

    A new kaempferol glycoside, named kaempferol 3-O-[6"-O-β-D-glucopyranosyl-6'"-O-α-L-rhamnopy ranosyl-2""-O-α-L-rharnnopyranosyl]-β-D-glucopyranoside, was isolated from Hydrangea macrophylla (Thunb.) Seringe. Its structure was established by spectroscopic techniques including MS, IR, UV, and 2D NMR.

  14. Flavonol and flavone intakes in US health professionals

    NARCIS (Netherlands)

    Sampson, L.; Rimm, E.; Hollman, P.C.H.; Vries, de J.H.M.; Katan, M.B.

    2002-01-01

    Objective To determine flavonoid content of US foods, mean individual intakes, major food sources, and associations with other nutrients. Subjects US men (n=37,886) and women (n=78,886) who completed a semiquantitative food frequency questionnaire in 1990. Design Men and women completed a questionna

  15. Clinical benefit and preservation of flavonols in dark chocolate manufacturing.

    Science.gov (United States)

    McShea, Andrew; Ramiro-Puig, Emma; Munro, Sandra B; Casadesus, Gemma; Castell, Margarida; Smith, Mark A

    2008-11-01

    The consumption of high-cacao-content chocolate has been associated with positive health benefits ascribed to flavanol [corrected] antioxidants derived from the ground, fermented cocoa seeds of Theobroma cacao. However, flavanols [corrected] impart a bitter, astringent flavor to foodstuffs, frequently masked in chocolates and confections by aggressive processing and adulteration with other flavors. Recent reports have implied that not all varieties of dark chocolate are created equally, and significant caveats exist regarding its potential health benefits. It is perhaps not surprising that extensive processing, dilution, and the addition of flavor modifiers may improve the palatability of chocolate, but could have negative nutritional and clinical benefits. This article examines the chemical composition of chocolate and the clinical data associated with the consumption of flavonoid-rich cocoa. We review the steps in chocolate manufacturing that directly affect the antioxidant levels in chocolate products, and the caveats associated with claims of health benefits from the consumption of dark chocolate.

  16. Tomato ( Lycopersicon esculentum ) seeds: new flavonols and cytotoxic effect.

    Science.gov (United States)

    Ferreres, Federico; Taveira, Marcos; Pereira, David M; Valentão, Patrícia; Andrade, Paula B

    2010-03-10

    In this study, seeds of Lycopersicon esculentum Mill. were analyzed by HPLC/UV-PAD/MS(n)-ESI. Fourteen flavonoids were identified, including quercetin, kaempferol, and isorhamnetin derivatives, with 13 of them being reported for the first time in tomato seeds. The major identified compounds were quercetin-3-O-sophoroside, kaempferol-3-O-sophoroside, and isorhamnetin-3-O-sophoroside. A significant cell proliferation inhibition (>80%), against rat basophile leukemia (RBL-2H3) cell line, was observed with this extract (IC(50) = 5980 microg/mL). For acetylcholinesterase inhibitory activity, a concentration-dependent effect was verified (IC(20) = 2400 microg/mL). The same behavior was noted regarding antioxidant capacity, evaluated against DPPH (IC(10) = 284 microg/mL), nitric oxide (IC(25) = 396 microg/L), and superoxide radicals (IC(25) = 3 microg/mL).

  17. Bioavailability of the dietary antioxidant flavonol quercetin in man.

    NARCIS (Netherlands)

    Hollman, P.C.H.; Trijp, van J.M.P.; Mengelers, M.J.B.; Vries, de J.H.M.; Katan, M.B.

    1997-01-01

    Quercetin, a dietary antioxidant flavonoid, has anticarcinogenic properties. We quantified the absorption of quercetin in ileostomists. Absorption was 52 ± 5␏or quercetin glucosides from onions, 17 ± 15␏or quercetin rutinoside, and 24 ± 9␏or quercetin aglycone. The plasma quercetin concentration in

  18. Flavonol 3-O-Glycosides from Three Algerian Bupleurum Species

    OpenAIRE

    Reguia Bencheraiet; Ahmed Kabouche; Zahia Kabouche; Rachid Touzani; Maurice Jay

    2012-01-01

    Flavonoids distribution in three algerian Bupleureum (Apiaceae) species has been investigated. Quercetin (1), quercetin 3-rutinoside (2) and isorhamnetin 3-rutinoside (3) were found in the endemic species B. plantagineum Desf. Three kaempferol glycosides, kaempferol 3-glucoside (4), kaempferol 3-galactoside (5), kaempferol 3-rutinoside (6) and three quercetin glycosides, quercetin 3-rutinoside (2), quercetin 3-glucoside (7) and quercetin 3-galactoside (8), have been isolated from B. fruticosu...

  19. Gene expression and metabolite profiling of developing highbush blueberry fruit indicates transcriptional regulation of flavonoid metabolism and activation of abscisic acid metabolism.

    Science.gov (United States)

    Zifkin, Michael; Jin, Alena; Ozga, Jocelyn A; Zaharia, L Irina; Schernthaner, Johann P; Gesell, Andreas; Abrams, Suzanne R; Kennedy, James A; Constabel, C Peter

    2012-01-01

    Highbush blueberry (Vaccinium corymbosum) fruits contain substantial quantities of flavonoids, which are implicated in a wide range of health benefits. Although the flavonoid constituents of ripe blueberries are known, the molecular genetics underlying their biosynthesis, localization, and changes that occur during development have not been investigated. Two expressed sequence tag libraries from ripening blueberry fruit were constructed as a resource for gene identification and quantitative real-time reverse transcription-polymerase chain reaction primer design. Gene expression profiling by quantitative real-time reverse transcription-polymerase chain reaction showed that flavonoid biosynthetic transcript abundance followed a tightly regulated biphasic pattern, and transcript profiles were consistent with the abundance of the three major classes of flavonoids. Proanthocyanidins (PAs) and corresponding biosynthetic transcripts encoding anthocyanidin reductase and leucoanthocyanidin reductase were most concentrated in young fruit and localized predominantly to the inner fruit tissue containing the seeds and placentae. Mean PA polymer length was seven to 8.5 subunits, linked predominantly via B-type linkages, and was relatively constant throughout development. Flavonol accumulation and localization patterns were similar to those of the PAs, and the B-ring hydroxylation pattern of both was correlated with flavonoid-3'-hydroxylase transcript abundance. By contrast, anthocyanins accumulated late in maturation, which coincided with a peak in flavonoid-3-O-glycosyltransferase and flavonoid-3'5'-hydroxylase transcripts. Transcripts of VcMYBPA1, which likely encodes an R2R3-MYB transcriptional regulator of PA synthesis, were prominent in both phases of development. Furthermore, the initiation of ripening was accompanied by a substantial rise in abscisic acid, a growth regulator that may be an important component of the ripening process and contribute to the regulation of

  20. TOWARD MORE EFFECTIVE REGULATION

    Energy Technology Data Exchange (ETDEWEB)

    J. GRAF

    2000-06-01

    This paper proposes a model relationship between the operator engaged in a hazardous activity, the regulator of that activity, and the general public. The roles and responsibilities of each entity are described in a way that allows effective communication flow. The role of the regulator is developed using the steam boiler as an example of a hazard subject to regulation; however, the model applies to any regulated activity. In this model the safety analyst has the extremely important role of communicating sometimes difficult technical information to the regulator in a way that the regulator can provide credible assurance to the general public as to the adequacy of the control of the hazardous activity. The conclusion asserts that acceptance of the model, understanding of the roles and responsibilities and definition of who communicates what information to whom will mitigate frustration on the part of each of the three entities.

  1. Benchmarking and Regulation

    DEFF Research Database (Denmark)

    Agrell, Per J.; Bogetoft, Peter

    nchmarking methods, and in particular Data Envelopment Analysis (DEA), have become well-established and informative tools for economic regulation. DEA is now routinely used by European regulators to set reasonable revenue caps for energy transmission and distribution system operators....... The application of benchmarking in regulation, however, requires specific steps in terms of data validation, model specification and outlier detection that are not systematically documented in open publications, leading to discussions about regulatory stability and economic feasibility of these techniques....... In this paper, we review the modern foundations for frontier-based regulation and we discuss its actual use in several jurisdictions....

  2. Reconceptualizing Civil Regulation

    DEFF Research Database (Denmark)

    Galang, Roberto Martin; Castello, Itziar

    2011-01-01

    This article re-conceptualizes the notion of civil regulation, through an analysis of 775 projects by firms located in 21 Asian countries, wherein we map the state of civil regulation initiatives in the region. We challenge two established assumptions in the Corporate Social Responsibility...... literature. First, contrary to what is commonly argued, we claim that strong states in Asia promote civil regulation in what we call the “paradox of the weak state”. Second, we not only argue that civil regulation is mainly enforced by multinational enterprises willing to promote international social...

  3. Novel regulators of spermatogenesis.

    Science.gov (United States)

    Fok, Kin Lam; Chen, Hao; Ruan, Ye Chun; Chan, Hsiao Chang

    2014-05-01

    Spermatogenesis is a multistep process that supports the production of millions of sperm daily. Understanding of the molecular mechanisms that regulate spermatogenesis has been a major focus for decades. Yet, the regulators involved in different cellular processes of spermatogenesis remain largely unknown. Human diseases that result in defective spermatogenesis have provided hints on the molecular mechanisms regulating this process. In this review, we have summarized recent findings on the function and signaling mechanisms of several genes that are known to be associated with disease or pathological processes, including CFTR, CD147, YWK-II and CT genes, and discuss their potential roles in regulating different processes of spermatogenesis.

  4. Plant Growth Regulators.

    Science.gov (United States)

    Nickell, Louis G.

    1978-01-01

    Describes the effect of "plant growth regulators" on plants, such as controlling the flowering, fruit development, plant size, and increasing crop yields. Provides a list of plant growth regulators which includes their chemical, common, and trade names, as well as their different use(s). (GA)

  5. Mortgage market regulation: Europe

    NARCIS (Netherlands)

    Aalbers, M.B.; Smith, S.J.

    2012-01-01

    Despite several European Union (EU) initiatives, there is only limited pan-European mortgage market regulation. The EU strategy can be characterised as one of parallel liberalisation and consolidation. This article highlights the key differences in regulation among European mortgage markets.

  6. Regulation of SUMO Modification

    NARCIS (Netherlands)

    P.M. Knipscheer (Puck Maria)

    2007-01-01

    textabstractThe small ubiquitin related modifier SUMO is a posttranslational modifier that functions in a wide range of cellular processes like intracellular transport, cell cycle regulation, DNA repair and regulation of transcription. SUMO is an 11 kDa protein and is ligated to its target proteins

  7. AtROS1 overexpression provides evidence for epigenetic regulation of genes encoding enzymes of flavonoid biosynthesis and antioxidant pathways during salt stress in transgenic tobacco.

    Science.gov (United States)

    Bharti, Poonam; Mahajan, Monika; Vishwakarma, Ajay K; Bhardwaj, Jyoti; Yadav, Sudesh Kumar

    2015-09-01

    In plants, epigenetic changes have been identified as regulators of developmental events during normal growth as well as environmental stress exposures. Flavonoid biosynthetic and antioxidant pathways play a significant role in plant defence during their exposure to environmental cues. The aim of this study was to unravel whether genes encoding enzymes of flavonoid biosynthetic and antioxidant pathways are under epigenetic regulation, particularly DNA methylation, during salt stress. For this, a repressor of silencing from Arabidopsis, AtROS1, was overexpressed in transgenic tobacco. Generated transgenics were evaluated to examine the influence of AtROS1 on methylation status of promoters as well as on coding regions of genes encoding enzymes of flavonoids biosynthesis and antioxidant pathways. Overexpression of AtROS1 increases the demethylation levels of both promoters as well as coding regions of genes encoding chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase, flavonol synthase, dihydroflavonol 4-reductase, and anthocyanidin synthase of the flavonoid biosynthetic pathway, and glutathione S-transferase, ascorbate peroxidase, glutathione peroxidase, and glutathione reductase of the antioxidant pathway during control conditions. The level of demethylation was further increased at promoters as well as coding regions of these genes during salt-stress conditions. Transgenic tobacco overexpressing AtROS1 showed tolerance to salt stress that could have been due to the higher expression levels of the genes encoding enzymes of the flavonoid biosynthetic and antioxidant pathways. This is the first comprehensive study documenting the epigenetic regulation of flavonoid biosynthetic and antioxidant pathways during salt-stress exposure of plants. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  8. Public regulators and CSR

    DEFF Research Database (Denmark)

    Buhmann, Karin

    2016-01-01

    for responsible business conduct, connecting to social expectations and bridging to public regulation. This UN guidance has had a significant bearing on how public regulators seek to influence business conduct beyond Human Rights to broader Corporate Social Responsibility (CSR) concerns. Drawing on examples...... of such public regulatory governance, this article explores and explains developments towards a juridification of CSR entailing efforts by public regulators to reach beyond jurisdictional and territorial limitations of conventional public law to address adverse effects of transnational economic activity. Through...

  9. Epigenetic Regulation of Adipokines

    Directory of Open Access Journals (Sweden)

    Tho X. Pham

    2017-08-01

    Full Text Available Adipose tissue expansion in obesity leads to changes in the expression of adipokines, adipocyte-specific hormones that can regulate whole body energy metabolism. Epigenetic regulation of gene expression is a mechanism by which cells can alter gene expression through the modifications of DNA and histones. Epigenetic mechanisms, such as DNA methylation and histone modifications, are intimately tied to energy metabolism due to their dependence on metabolic intermediates such as S-adenosylmethionine and acetyl-CoA. Altered expression of adipokines in obesity may be due to epigenetic changes. The goal of this review is to highlight current knowledge of epigenetic regulation of adipokines.

  10. Volume regulation in epithelia

    DEFF Research Database (Denmark)

    Larsen, Erik Hviid; Hoffmann, Else Kay

    2016-01-01

    function of iso-osmotic fluid transport that depends on Na+ recirculation. The causative relationship is discussed for a fluid-absorbing and a fluid-secreting epithelium of which the Na+ recirculation mechanisms have been identified. A large number of transporters and ion channels involved in cell volume...... regulation are cloned. The volume-regulated anion channel (VRAC) exhibiting specific electrophysiological characteristics seems exclusive to serve cell volume regulation. This is contrary to K+ channels as well as cotransporters and exchange mechanisms that may serve both transepithelial transport and cell...

  11. Electrical installations and regulations

    CERN Document Server

    Whitfield, J F

    1966-01-01

    Electrical Installations and Regulations focuses on the regulations that apply to electrical installations and the reasons for them. Topics covered range from electrical science to alternating and direct current supplies, as well as equipment for providing protection against excess current. Cables, wiring systems, and final subcircuits are also considered, along with earthing, discharge lighting, and testing and inspection.Comprised of 12 chapters, this book begins with an overview of electrical installation work, traits of a good electrician, and the regulations governing installations. The r

  12. Sport Fishing Regulations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The regulations for sport fishing on St. Vincent National Wildlife Refuge are outlined in this document. Fishing is only permitted from sunrise to sunset, and only...

  13. Focus on PTEN regulation

    Directory of Open Access Journals (Sweden)

    Miriam eBermudez-Brito

    2015-07-01

    Full Text Available The role of PTEN as a tumour suppressor has been for a long time attributed to its lipid phosphatase activity against PI(3,4,5P3, the phospholipid product of the class I PI3Ks. Besides its traditional role as a lipid phosphatase at the plasma membrane, a wealth of data has shown that PTEN can function independently of its phosphatase activity and that PTEN also exists and plays a role in the nucleus, in cytoplasmic organelles and extracellularly. Accumulating evidence has shed light on diverse physiological functions of PTEN which are accompanied by a complex regulation of its expression and activity. PTEN levels and function are regulated transcriptionally, post-transcriptionally and post-translationally. PTEN is also sensitive to regulation by its interacting proteins and its localization. Herein, we summarize the current knowledge on mechanisms that regulate the expression and enzymatic activity of PTEN and its role in human diseases.

  14. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    - serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...... of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume......, controlled cell death and cellular migration. Volume regulatory mechanisms has long been in focus for regulating cellular proliferation and my thesis work have been focusing on the role of Cl- channels in proliferation with specific emphasis on ICl, swell. Pharmacological blockage of the ubiquitously...

  15. Regulation of cholesterol homeostasis

    NARCIS (Netherlands)

    van der Wulp, Mariette Y. M.; Verkade, Henkjan J.; Groen, Albert K.

    2013-01-01

    Hypercholesterolemia is an important risk factor for cardiovascular disease. It is caused by a disturbed balance between cholesterol secretion into the blood versus uptake. The pathways involved are regulated via a complex interplay of enzymes, transport proteins, transcription factors and

  16. Regulation and controlled synchronization

    NARCIS (Netherlands)

    Huijberts, H.J.C.; Huijberts, H.J.C.; Nijmeijer, Henk; Willems, R.M.A.

    1998-01-01

    We investigate the problem of controlled synchronization as a regulator problem. In controlled synchronization one is given autonomous transmitter dynamics and controlled receiver dynamics. The question is to find a (output) feedback controller that achieves matching between transmitter and

  17. Structural biology of starch-degrading enzymes and their regulation

    DEFF Research Database (Denmark)

    Møller, Marie Sofie; Svensson, Birte

    2016-01-01

    Starch is a major energy source for all domains of life. Recent advances in structures of starch-degrading enzymes encompass the substrate complex of starch debranching enzyme, the function of surface binding sites in plant isoamylase, details on individual steps in the mechanism of plant...... disproportionating enzyme and a self-stabilised conformation of amylose accommodated in the active site of plant α-glucosidase. Important inhibitor complexes include a flavonol glycoside, montbretin A, binding at the active site of human pancreatic α-amylase and barley limit dextrinase inhibitor binding...

  18. Structural biology of starch-degrading enzymes and their regulation

    DEFF Research Database (Denmark)

    Møller, Marie Sofie; Svensson, Birte

    2016-01-01

    Starch is a major energy source for all domains of life. Recent advances in structures of starch-degrading enzymes encompass the substrate complex of starch debranching enzyme, the function of surface binding sites in plant isoamylase, details on individual steps in the mechanism of plant...... disproportionating enzyme and a self-stabilised conformation of amylose accommodated in the active site of plant α-glucosidase. Important inhibitor complexes include a flavonol glycoside, montbretin A, binding at the active site of human pancreatic α-amylase and barley limit dextrinase inhibitor binding...... to the debranching enzyme, limit dextrinase using a new binding mode for cereal protein inhibitors....

  19. Worldwide regulations for mycotoxins.

    Science.gov (United States)

    van Egmond, Hans P

    2002-01-01

    Since the discovery of the aflatoxins in the 1960s, regulations have been established in many countries to protect the consumer from the harmful effects of mycotoxins that may contaminate foodstuffs. Various factors play a role in the decision-making process of setting limits for mycotoxins. These include scientific factors such as the availability of toxicological data, survey data, knowledge about the distribution of mycotoxins in commodities, and analytical methodology. Economical and political factors such as commercial interests and sufficiency of food supply have their impact as well. International enquiry's on existing mycotoxin legislation in foodstuffs and animal feedstuffs have been carried out several times in the 1980s and 1990s and details about tolerances, legal basis, responsible authorities, official protocols of analysis and sampling have been published. Recently a comprehensive update on worldwide regulations was published as FAO Food and Nutrition Paper 64. It appeared that at least 77 countries now have specific regulations for mycotoxins, 13 countries are known to have no specific regulations, whereas no data are available for about 50 countries, many of them in Africa. Over the years, a large diversity in tolerance levels for mycotoxins has remained. Some free trade zones (EU, MERCOSUR) are in the process of harmonizing the limits and regulations for mycotoxins in their respective member states, but it is not likely that worldwide harmonized limits for mycotoxins will soon be within reach.

  20. To regulate or not to regulate?

    Energy Technology Data Exchange (ETDEWEB)

    Mason, G.; Wrixon, A. [IAEA, Vienna (Austria)

    2006-07-01

    Full text of publication follows: In Hamlet famous soliloquy to be or not to be, he wrestles with the perennial human problem of choosing the right course of action in difficult circumstances. In recent years, we have witnessed a cast of thousands playing out a long-running scene that seems to echo Hamlet dilemma on a rather more prosaic level. When is it necessary to apply regulations to the control of exposure to ionizing radiation and when is regulatory control not warranted? This seemingly straightforward question has brought out the philosopher, ethician, lawyer, pragmatist, orator in simple radiation protection folk and has led to passionate debate on numerous occasions. This paper attempts an answer based on a review of recent developments. For deciding when to apply regulatory controls, several concepts have evolved over time, including exemption of practices and sources, exclusion of exposures and clearance of materials. These have different origins, purposes and characteristics. Exemption and clearance have often been associated with triviality of risk, while exclusion has been related to un-amenability of control. For each concept, criteria have been developed to assist the regulator in reaching a decision, but there has much disputation over numerical values. This paper briefly reviews and analyses recent developments and attempts to clarify the problem from first principles. The conclusion is that the underlying issue in each case is to determine when regulatory controls become unwarranted: that is, when the societal resources expended in applying them and complying with them would be disproportionate to any benefit they might bring. This is a natural extension of the principle of optimization of protection to the regulatory control of protection, in the context of exposure to radiation at very low levels. It also reflects common expectations of good governance: wise management of finite societal resources and avoidance of unwarranted controls on

  1. HPLC-ECD determination of flavonols from Ginkgo biloba leaf extracts in rat plasma and its pharmacokinetic study%HPLC-ECD法测定大鼠血浆中银杏叶黄酮成分及药代动力学研究

    Institute of Scientific and Technical Information of China (English)

    张颖; 刘建勋; 林力; 张强强; 王建农

    2011-01-01

    目的:建立大鼠灌胃银杏叶提取物后血浆中黄酮类成分的灵敏分析方法,并进行药代动力学研究.方法:血浆样品经葡萄糖醛酸苷水解酶水解后,采用高效液相色谱分离及电化学检测,同时分析大鼠血浆样品中槲皮素、异鼠李素和山柰酚.色谱柱为Agilent Zorbax Eclipse XDB-C8(150 mm x4.6 mm,5μm),流动相为甲醇-异丙醇-磷酸盐缓冲液(磷酸二氢钠-磷酸,pH=2)(15:15:70),流速0.8 mL·min-1,检测电压为200 mV,柱温30℃.结果:槲皮素、异鼠李素和山柰酚与其他内源性和药源性成分达到良好分离;最低检测浓度达到0.5 ng·mL-1;平均提取回收率分别为88.7%,86.2%,87.0%;准确度在92.7%~105.3%之间,日内精密度RSD小于6.6%,日间精密度RSD小于14.1%,样品分析时间为20 min.大鼠灌胃给予银杏叶提取物10mg·kg-1后,酶水解血浆中槲皮素、异鼠李素和山柰酚的半衰期分别为(3.53±1.88)h,(6.94±4.05)h,(3.97 4±2.30)h;3个黄酮类成分在大鼠血浆中都显示明显的二次达峰现象.结论:建立的检测方法能灵敏、特异、准确,可用于银杏叶提取物灌胃给药后黄酮类成分的药代动力学研究.%Objective : To establish a sensitive method for the quantification of flavonols from rat plasma after intragastric administration of Ginkgo biloba leaf extracts. Methods : HPLC with electrochemical detection( ECD) was employed to quantify quercetin ,isorhamnetin and kaempferol simultaneously after plasma samples were hydrolyzed by glucuronidase. The sample was separated by Agilent Zorbax Eclipse XDB - C8 (150 mm ×4. 6 mm,5 μm) column and eluted by the mobile phase composed of methanol - isopropanol - phosphate buffer( NaH2PO4 - H3PO4 , pH = 2) ( 15: 15: 70)at column temperature of 30 ℃ ,and the flow rate was 0. 8 mL · min -1. The potential of analysis cell was selected as 200 mV. Results : The analysis of plasma samples could be performed in 20 min with the quantitative limit of 0.5 ng ·mL-1

  2. Collaborative Tax Regulation

    DEFF Research Database (Denmark)

    Boll, Karen

    2016-01-01

    their customer bases decline to commercially non-viable levels. The analysis is framed by public governance literature and argues that the regulation is an example of collaborative or interactive governance, because the tax administrators do not regulate non-compliance directly, but activate external...... stakeholders, i.e. the consumers, in the regulatory craft. The study is based on a qualitative methodology and draws on a unique case of regulation in the cleaning sector. This sector is at high risk of tax evasion and human exploitation of vulnerable workers operating in the informal economy. The article has...... implications for how tax practitioners think about collaborative and interactive regulatory initiatives. While the tax administration in the study sees the approach as effective, the analysis shows that there are a number of caveats in relation to regularity, public listing, costs and revenue focus...

  3. Staff rules and regulations

    CERN Multimedia

    HR Department

    2007-01-01

    The 11th edition of the Staff Rules and Regulations, dated 1 January 2007, adopted by the Council and the Finance Committee in December 2006, is currently being distributed to departmental secretariats. The Staff Rules and Regulations, together with a summary of the main modifications made, will be available, as from next week, on the Human Resources Department's intranet site: http://cern.ch/hr-web/internal/admin_services/rules/default.asp The main changes made to the Staff Rules and Regulations stem from the five-yearly review of employment conditions of members of the personnel. The changes notably relate to: the categories of members of the personnel (e.g. removal of the local staff category); the careers structure and the merit recognition system; the non-residence, installation and re-installation allowances; the definition of family, family allowances and family-related leave; recognition of partnerships; education fees. The administrative circulars, some of which are being revised following the ...

  4. Collaborative Tax Regulation

    DEFF Research Database (Denmark)

    Boll, Karen

    2016-01-01

    This article shows a new form of regulation within a tax administration where tax administrators abate tax evasion by nudging and motivating consumers to only purchase services from tax compliant businesses. This indirectly closes or forces tax evading businesses to change their practices, because...... their customer bases decline to commercially non-viable levels. The analysis is framed by public governance literature and argues that the regulation is an example of collaborative or interactive governance, because the tax administrators do not regulate non-compliance directly, but activate external...... implications for how tax practitioners think about collaborative and interactive regulatory initiatives. While the tax administration in the study sees the approach as effective, the analysis shows that there are a number of caveats in relation to regularity, public listing, costs and revenue focus...

  5. Volume Regulated Channels

    DEFF Research Database (Denmark)

    Klausen, Thomas Kjær

    of volume perturbations evolution have developed system of channels and transporters to tightly control volume homeostasis. In the past decades evidence has been mounting, that the importance of these volume regulated channels and transporters are not restricted to the defense of cellular volume...... but are also essential for a number of physiological processes such as proliferation, controlled cell death, migration and endocrinology. The thesis have been focusing on two Channels, namely the swelling activated Cl- channel (ICl, swell) and the transient receptor potential Vanilloid (TRPV4) channel. I: Cl......- serves a multitude of functions in the mammalian cell, regulating the membrane potential (Em), cell volume, protein activity and the driving force for facilitated transporters giving Cl- and Cl- channels a major potential of regulating cellular function. These functions include control of the cell cycle...

  6. The Impact of Regulating Social Science Research with Biomedical Regulations

    Science.gov (United States)

    Durosinmi, Brenda Braxton

    2011-01-01

    The Impact of Regulating Social Science Research with Biomedical Regulations Since 1974 Federal regulations have governed the use of human subjects in biomedical and social science research. The regulations are known as the Federal Policy for the Protection of Human Subjects, and often referred to as the "Common Rule" because 18 Federal…

  7. Other-Regulation in Collaborative Groups: Implications for Regulation Quality

    Science.gov (United States)

    Rogat, Toni Kempler; Adams-Wiggins, Karlyn R.

    2014-01-01

    The current study examines variation in other-regulation, conceptualized as efforts by one student to regulate their group's work. This study extends research which has conceptualized other-regulation as temporarily guiding others' conceptual understanding and skill development by broadening the spectrum of other-regulation to include…

  8. The Impact of Regulating Social Science Research with Biomedical Regulations

    Science.gov (United States)

    Durosinmi, Brenda Braxton

    2011-01-01

    The Impact of Regulating Social Science Research with Biomedical Regulations Since 1974 Federal regulations have governed the use of human subjects in biomedical and social science research. The regulations are known as the Federal Policy for the Protection of Human Subjects, and often referred to as the "Common Rule" because 18 Federal…

  9. Nuclear regulation and safety

    Energy Technology Data Exchange (ETDEWEB)

    Hendrie, J.M.

    1982-01-01

    Nuclear regulation and safety are discussed from the standpoint of a hypothetical country that is in the process of introducing a nuclear power industry and setting up a regulatory system. The national policy is assumed to be in favor of nuclear power. The regulators will have responsibility for economic, reliable electric production as well as for safety. Reactor safety is divided into three parts: shut it down, keep it covered, take out the afterheat. Emergency plans also have to be provided. Ways of keeping the core covered with water are discussed. (DLC)

  10. Cyberplagiarism in University Regulations

    Directory of Open Access Journals (Sweden)

    Santiago Cavanillas

    2008-12-01

    Full Text Available The article examines the legal framework for plagiarism, and its twofold nature of illicit appropriation (from the author of the plagiarized work and fraud (with regard to the target audience of the plagiarism. Based on these premises, academic cyberplagiarism is analysed as a form of plagiarism carried out using electronic tools in the university setting. The question of responsibility (who can regulate the legal consequences of plagiarism? before and after the Ley Orgánica de Universidades (organic law on universities, LOU is studied, as is the disciplinary handling of cyberplagiarism with the limited regulations currently in place at universities.

  11. Design of dual pressure regulator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Soo; Kim, Kang Dae; Kim, Myoung Sub [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2008-07-01

    In this paper, we designed sandwich type pressure regulator for air pressure control system. As a result of research, we obtained several important conclusions. First, we decided theory of poppet valve and relief valve which are used in sandwich type pressure regulator, and then designed prototype of pressure regulator. Second, we organized circuit diagram of dual pressure regulator of air pressure control system.

  12. Markets, religion, regulation

    DEFF Research Database (Denmark)

    Fischer, Johan

    2016-01-01

    of regulation, certification and standardization on a global scale. Building on research on global kosher (a Hebrew term meaning “fit” or “proper”), halal (an Arabic word that literally means “permissible” or “lawful”) and Hindu vegetarianism this paper argues that these economies or markets to a large extent...

  13. Vehicle recycling regulations

    DEFF Research Database (Denmark)

    Smink, Carla

    2007-01-01

    The number of end-of-life vehicles (ELVs) in the EU is increasing continously. Around 75 percent of an ELV are recyclable metals. The forecast growth in the number of ELVs calls for regulation that aims to minimise the environmental impact of a car. Using Denmark as an example, this article...

  14. Situated bio-regulation

    DEFF Research Database (Denmark)

    Prainsack, Barbara; Wahlberg, Ayo

    2013-01-01

    Several years ago, both authors engaged in research into bioscience and biomedical regulation in Asian countries. One of us (BP) explored why the regulatory and discursive embedding of human embryonic stem cell in Israel was much more permissive than elsewhere. The other author (AW) sought to und...

  15. Regulated Gene Therapy.

    Science.gov (United States)

    Breger, Ludivine; Wettergren, Erika Elgstrand; Quintino, Luis; Lundberg, Cecilia

    2016-01-01

    Gene therapy represents a promising approach for the treatment of monogenic and multifactorial neurological disorders. It can be used to replace a missing gene and mutated gene or downregulate a causal gene. Despite the versatility of gene therapy, one of the main limitations lies in the irreversibility of the process: once delivered to target cells, the gene of interest is constitutively expressed and cannot be removed. Therefore, efficient, safe and long-term gene modification requires a system allowing fine control of transgene expression.Different systems have been developed over the past decades to regulate transgene expression after in vivo delivery, either at transcriptional or post-translational levels. The purpose of this chapter is to give an overview on current regulatory system used in the context of gene therapy for neurological disorders. Systems using external regulation of transgenes using antibiotics are commonly used to control either gene expression using tetracycline-controlled transcription or protein levels using destabilizing domain technology. Alternatively, specific promoters of genes that are regulated by disease mechanisms, increasing expression as the disease progresses or decreasing expression as disease regresses, are also examined. Overall, this chapter discusses advantages and drawbacks of current molecular methods for regulated gene therapy in the central nervous system.

  16. Federal Gasoline Regulations

    Science.gov (United States)

    The Clean Air Act requires EPA to regulate fuels and fuel additives for use in mobile sources if such fuel, fuel additive or any emission products causes or contributes to air or water pollution that may endanger the public health or welfare.

  17. Situated bio-regulation

    DEFF Research Database (Denmark)

    Prainsack, Barbara; Wahlberg, Ayo

    2013-01-01

    Several years ago, both authors engaged in research into bioscience and biomedical regulation in Asian countries. One of us (BP) explored why the regulatory and discursive embedding of human embryonic stem cell in Israel was much more permissive than elsewhere. The other author (AW) sought to und...

  18. Legislation and regulation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    This document presents the fulfilling of the Brazilian obligations under the Convention on Nuclear Safety. The Chapter 3 of the document contains some details about the Brazilian legislation and regulation, the legislative and regulatory framework, regulatory body and responsibility of the license holder.

  19. Regulation of cholesterol homeostasis

    NARCIS (Netherlands)

    van der Wulp, Mariette Y. M.; Verkade, Henkjan J.; Groen, Albert K.

    2013-01-01

    Hypercholesterolemia is an important risk factor for cardiovascular disease. It is caused by a disturbed balance between cholesterol secretion into the blood versus uptake. The pathways involved are regulated via a complex interplay of enzymes, transport proteins, transcription factors and non-codin

  20. Regulating groundwater use

    NARCIS (Netherlands)

    Hoogesteger van Dijk, Jaime; Wester, Flip

    2017-01-01

    Around the world it has proven very difficult to develop policies and interventions that ensure socio-environmentally sustainable groundwater use and exploitation. In the state of Guanajuato, Central Mexico, both the national government and the decentralized state government have pursued to regulate

  1. Regulating the private security industry

    CERN Document Server

    Percy, Sarah

    2002-01-01

    The under-regulation of the private security industry has increasingly become a topic of media and academic interest. This Adelphi Paper enters the debate by explaining why the industry requires further regulation, and what is wrong with the current system. It begins by briefly defining the industry and explaining the need for more effective regulation, before analysing three types of regulation: domestic, international and informal (including self-regulation).

  2. Dimensionally regulated pentagon integrals

    CERN Document Server

    Bern, Z; Kosower, D A

    1994-01-01

    We present methods for evaluating the Feynman parameter integrals associated with the pentagon diagram in 4-2 epsilon dimensions, along with explicit results for the integrals with all masses vanishing or with one non-vanishing external mass. The scalar pentagon integral can be expressed as a linear combination of box integrals, up to O(epsilon) corrections, a result which is the dimensionally-regulated version of a D=4 result of Melrose, and of van Neerven and Vermaseren. We obtain and solve differential equations for various dimensionally-regulated box integrals with massless internal lines, which appear in one-loop n-point calculations in QCD. We give a procedure for constructing the tensor pentagon integrals needed in gauge theory, again through O(epsilon^0).

  3. Probiotics and Appetite Regulation

    DEFF Research Database (Denmark)

    Bjerg, Anne Toksvig

    resistance and blood lipid profile among others. Probiotics which are health promoting bacteria can potentially be used to affect the GM and thereby change metabolic outcomes of the host. Animal studies have shown associations between intake of probiotics and appetite regulation, but currently no human...... studies have investigated this effect. Supplementation with different probiotic strains have been shown to have an effect on blood lipid profiles in both animals and humans and the mechanisms behind have been studied in vitro and in rodents. The aim of the present thesis was to examine in an ex vivo...... intestine, in an animal study and in two human studies the effect of the probiotic bacteria Lactobacillus paracasei subsp. paracasei L. casei W8 (W8) on appetite regulation, blood lipids and blood fatty acids. In addition, it was investigated if W8 had an effect on the fecal microbiota of the human...

  4. Regulation of Meiotic Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Gregory p. Copenhaver

    2011-11-09

    Meiotic recombination results in the heritable rearrangement of DNA, primarily through reciprocal exchange between homologous chromosome or gene conversion. In plants these events are critical for ensuring proper chromosome segregation, facilitating DNA repair and providing a basis for genetic diversity. Understanding this fundamental biological mechanism will directly facilitate trait mapping, conventional plant breeding, and development of genetic engineering techniques that will help support the responsible production and conversion of renewable resources for fuels, chemicals, and the conservation of energy (1-3). Substantial progress has been made in understanding the basal recombination machinery, much of which is conserved in organisms as diverse as yeast, plants and mammals (4, 5). Significantly less is known about the factors that regulate how often and where that basal machinery acts on higher eukaryotic chromosomes. One important mechanism for regulating the frequency and distribution of meiotic recombination is crossover interference - or the ability of one recombination event to influence nearby events. The MUS81 gene is thought to play an important role in regulating the influence of interference on crossing over. The immediate goals of this project are to use reverse genetics to identify mutants in two putative MUS81 homologs in the model plant Arabidopsis thaliana, characterize those mutants and initiate a novel forward genetic screen for additional regulators of meiotic recombination. The long-term goal of the project is to understand how meiotic recombination is regulated in higher eukaryotes with an emphasis on the molecular basis of crossover interference. The ability to monitor recombination in all four meiotic products (tetrad analysis) has been a powerful tool in the arsenal of yeast geneticists. Previously, the qrt mutant of Arabidopsis, which causes the four pollen products of male meiosis to remain attached, was developed as a facile system

  5. CNS regulation of appetite.

    Science.gov (United States)

    Harrold, Joanne A; Dovey, Terry M; Blundell, John E; Halford, Jason C G

    2012-07-01

    This article reviews the regulation of appetite from a biopsychological perspective. It considers psychological experiences and peripheral nutritional systems (both episodic and tonic) and addresses their relationship with the CNS networks that process and integrate their input. Whilst such regulatory aspects of obesity focus on homeostatic control mechanisms, in the modern environment hedonic aspects of appetite are also critical. Enhanced knowledge of the complexity of appetite regulation and the mechanisms that sustain obesity indicate the challenge presented by management of the obesity epidemic. Nonetheless, effective control of appetite expression remains a critical therapeutic target for weight management. Currently, strategies which utilise a combination of agents to target both homeostatic and hedonic control mechanisms represent the most promising approaches. This article is part of a Special Issue entitled 'Central Control of Food Intake'. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Hormonal Regulators of Appetite

    OpenAIRE

    Austin Juliana; Marks Daniel

    2008-01-01

    Obesity is a significant cause of morbidity and mortality worldwide. There has been a significant worsening of the obesity epidemic mainly due to alterations in dietary intake and energy expenditure. Alternatively, cachexia, or pathologic weight loss, is a significant problem for individuals with chronic disease. Despite their obvious differences, both processes involve hormones that regulate appetite. These hormones act on specific centers in the brain that affect the sensations of hunger a...

  7. The regulation of hunting

    DEFF Research Database (Denmark)

    Abildtrup, Jens; Jensen, Frank

    2014-01-01

    This paper examines a tax/subsidy on hunters based on game population. The tax/subsidy is the difference between actual and optimal population multiplied by an individual, variable tax rate. The tax rate is, among other things, based on the difference between the marginal value of the game...... population to the hunter and the regulator and differences in user costs of the population. The paper shows that the population tax/subsidy secures a first-best optimum....

  8. Computing Borel's Regulator II

    CERN Document Server

    Choo, Zacky; Sánchez-García, Rubén J; Snaith, Victor P

    2009-01-01

    In our earlier article we described a power series formula for the Borel regulator evaluated on the odd-dimensional homology of the general linear group of a number field and, concentrating on dimension three for simplicity, described a computer algorithm which calculates the value to any chosen degree of accuracy. In this sequel we give an algorithm for the construction of the input homology classes and describe the results of one cyclotomic field computation.

  9. [Sleep: regulation and phenomenology].

    Science.gov (United States)

    Vecchierini, M-F

    2013-12-01

    This article describes the two-process model of sleep regulation. The 24-hour sleep-wake cycle is regulated by a homeostatic process and an endogenous, 2 oscillators, circadian process, under the influence of external synchronisers. These two processes are partially independent but influence each other, as shown in the two-sleep-process auto-regulation model. A reciprocal inhibition model of two interconnected neuronal groups, "SP on" and "SP off", explains the regular recurrence of paradoxical sleep. Sleep studies have primarily depended on observation of the subject and have determined the optimal conditions for sleep (position, external conditions, sleep duration and need) and have studied the consequences of sleep deprivation or modifications of sleep schedules. Then, electrophysiological recordings permitted the classification of sleep stages according to the observed EEG patterns. The course of a night's sleep is reported on a "hypnogram". The adult subject falls asleep in non-REM sleep (N1), then sleep deepens progressively to stages N2 and N3 with the appearance of spindles and slow waves (N2). Slow waves become more numerous in stage N3. Every 90minutes REM sleep recurs, with muscle atonia and rapid eye movements. These adult sleep patterns develop progressively during the 2 first years of life as total sleep duration decreases, with the reduction of diurnal sleep and of REM sleep. Around 2 to 4 months, spindles and K complexes appear on the EEG, with the differentiation of light and deep sleep with, however, a predominance of slow wave sleep.

  10. Staff rules and regulations

    CERN Document Server

    HR Department

    2007-01-01

    The 11th edition of the Staff Rules and Regulations, dated 1 January 2007, adopted by the Council and the Finance Committee in December 2006, is currently being distributed to departmental secretariats. The Staff Rules and Regulations, together with a summary of the main modifications made, will be available, as from next week, on the Human Resources Department's intranet site: http://cern.ch/hr-web/internal/admin_services/rules/default.asp The main changes made to the Staff Rules and Regulations stem from the five-yearly review of employment conditions of members of the personnel. The changes notably relate to: the categories of members of the personnel (e.g. removal of the local staff category); the careers structure and the merit recognition system; the non-residence, installation and re-installation allowances; the definition of family, family allowances and family-related leave; recognition of partnerships; education fees. The administrative circulars, some of which are being revised following the m...

  11. Improving CS regulations.

    Energy Technology Data Exchange (ETDEWEB)

    Nesse, R.J.; Scheer, R.M.; Marasco, A.L.; Furey, R.

    1980-10-01

    President Carter issued Executive Order 12044 (3/28/78) that required all Federal agencies to distinguish between significant and insignificant regulations, and to determine whether a regulation will result in major impacts. This study gathered information on the impact of the order and the guidelines on the Office of Conservation and Solar Energy (CS) regulatory practices, investigated problems encountered by the CS staff when implementing the order and guidelines, and recommended solutions to resolve these problems. Major tasks accomplished and discussed are: (1) legislation, Executive Orders, and DOE Memoranda concerning Federal administrative procedures relevant to the development and analysis of regulations within CS reviewed; (2) relevant DOE Orders and Memoranda analyzed and key DOE and CS staff interviewed in order to accurately describe the current CS regulatory process; (3) DOE staff from the Office of the General Counsel, the Office of Policy and Evaluation, the Office of the Environment, and the Office of the Secretary interviewed to explore issues and problems encountered with current CS regulatory practices; (4) the regulatory processes at five other Federal agencies reviewed in order to see how other agencies have approached the regulatory process, dealt with specific regulatory problems, and responded to the Executive Order; and (5) based on the results of the preceding four tasks, recommendations for potential solutions to the CS regulatory problems developed. (MCW)

  12. Environmental regulations and business decisions

    OpenAIRE

    Gray, Wayne B.

    2015-01-01

    Environmental regulations raise production costs at regulated firms, though in most cases the costs are only a small fraction of a firm’s total costs. Productivity tends to fall, and firms may shift new investment and production to locations with less stringent regulation. However, environmental regulations have had enormous benefits in terms of lives saved and illnesses averted, especially through reductions in airborne particulates. The potential health gains may be even greater in developi...

  13. [Regulation of terpene metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, R.

    1992-01-01

    This report describes accomplishments over the past year on understanding of terpene synthesis in mint plants and sage. Specifically reported are the fractionation of 4-S-limonene synthetase, the enzyme responsible for the first committed step to monoterpene synthesis, along with isolation of the corresponding RNA and DNA cloning of its gene; the localization of the enzyme within the oil glands, regulation of transcription and translation of the synthetase, the pathway to camphor biosynthesis,a nd studies on the early stages and branch points of the isoprenoid pathway.

  14. FACTORS REGULATING LIBERAL TRANSLATION

    Institute of Scientific and Technical Information of China (English)

    龚海红

    2012-01-01

    Literal translation and liberal translation are two important methods and both play key roles in translation.However,some textbooks say that most translations are literal translations while others maintain most are liberal ones,besides,some others suggest a combination of the two.This paper focuses on the facts that regulate liberal translation.Because of the differences in culture,society,history,geography,and so on,there exists a great difference between Chinese language and English language,which does naturally lead to the liberal translation.

  15. The regulation of hunting

    DEFF Research Database (Denmark)

    Abildtrup, Jens; Jensen, Frank

    of the individual harvest. However, information about the individual harvest may be costly to obtain. Thus, we may have to look for alternatives to the existing system. This paper proposes a population tax/subsidy as an alternative which is the difference between the actual and optimal population multiplied...... by an individual, variable tax rate. The variable tax rate is, among other things, based on the difference in marginal value of the population between the hunter and the regulator. The paper shows that the population tax/subsidy secures a first-best optimum. Thus, the population tax is a good alternative...

  16. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  17. Genetic mapping of semi-polar metabolites in pepper fruits (Capsicum sp.): towards unravelling the molecular regulation of flavonoid quantitative trait loci.

    Science.gov (United States)

    Wahyuni, Yuni; Stahl-Hermes, Vanessa; Ballester, Ana-Rosa; de Vos, Ric C H; Voorrips, Roeland E; Maharijaya, Awang; Molthoff, Jos; Zamora, Marcela Viquez; Sudarmonowati, Enny; Arisi, Ana Carolina Maisonnave; Bino, Raoul J; Bovy, Arnaud G

    2014-01-01

    Untargeted LCMS profiling of semi-polar metabolites followed by metabolite quantitative trait locus (mQTL) analysis was performed in ripe pepper fruits of 113 F2 plants derived from a cross between Capsicum annuum AC1979 (no. 19) and Capsicum chinense No. 4661 Selection (no. 18). The parental accessions were selected based on their variation in fruit morphological characteristics and fruit content of some target phytonutrients. Clear segregation of fruit colour and fruit metabolite profiles was observed in the F2 population. The F2 plants formed three clusters based on their metabolite profiles. Of the total of 542 metabolites, 52 could be annotated, including a range of flavonoids, such as flavone C-glycosides, flavonol O-glycosides and naringenin chalcone, as well as several phenylpropanoids, a capsaicin analogue, fatty acid derivatives and amino acid derivatives. Interval mapping revealed 279 mQTLs in total. Two mQTL hotspots were found on chromosome 9. These two chromosomal regions regulated the relative levels of 35 and 103 metabolites, respectively. Analysis also revealed an mQTL for a capsaicin analogue, located on chromosome 7. Confirmation of flavonoid mQTLs using a set of six flavonoid candidate gene markers and their corresponding expression data (expression QTLs) indicated the Ca-MYB12 transcription factor gene on chromosome 1 and the gene encoding flavone synthase (FS-2) on chromosome 6 as likely causative genes determining the variation in naringenin chalcone and flavone C-glycosides, respectively, in this population. The combination of large-scale metabolite profiling and QTL analysis provided valuable insight into the genomic regions and genes important for the production of (secondary) metabolites in pepper fruit. This will impact breeding strategies aimed at optimising the content of specific metabolites in pepper fruit.

  18. The Regulation of Street Foods

    DEFF Research Database (Denmark)

    Forkour, John Boulard; Samuelsen, Helle; Yeboah, Eric Henry

    2017-01-01

    the challenges and negotiating strategies of regulators of street-vended foods in Ghana and analyses the implication for their relationship with street food vendors. The paper reveals that regulators operate in a context of limited resources, leading to a general feeling of neglect. In coping, regulators adopt...

  19. Transcriptome Analysis Reveals that Red and Blue Light Regulate Growth and Phytohormone Metabolism in Norway Spruce [Picea abies (L. Karst].

    Directory of Open Access Journals (Sweden)

    Fangqun OuYang

    yielded the higher IAA level. DELLA and phytochrome-interacting factor 3 (PIF3, involved in negative GA signaling, were also upregulated under blue light, which may be related to the lower GA level. Light quality also affects endogenous hormones by influencing secondary metabolism. Blue light promoted phenylpropanoid biosynthesis, phenylalanine metabolism, flavonoid biosynthesis and flavone and flavonol biosynthesis, accompanied by upregulation of most of the genes in their pathways. In conclusion, red light may promote stem growth by regulating biosynthesis of GAs, and blue light may promote flavonoid, lignin, phenylpropanoid and some hormones (such as jasmonic acid which were related to plant defense in Norway spruce, which might reduce the primary metabolites available for plant growth.

  20. [Regulation of terpene metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, R.

    1991-01-01

    During the last grant period, we have completed studies on the key pathways of monoterpene biosynthesis and catabolism in sage and peppermint, and have, by several lines of evidence, deciphered the rate-limiting step of each pathway. We have at least partially purified and characterized the relevant enzymes of each pathway. We have made a strong case, based on analytical, in vivo, and in vitro studies, that terpene accumulation depends upon the balance between biosynthesis and catabolism, and provided supporting evidence that these processes are developmentally-regulated and very closely associated with senescence of the oil glands. Oil gland ontogeny has been characterized at the ultrastructural level. We have exploited foliar-applied bioregulators to delay gland senescence, and have developed tissue explant and cell culture systems to study several elusive aspects of catabolism. We have isolated pure gland cell clusters and localized monoterpene biosynthesis and catabolism within these structures, and have used these preparations as starting materials for the purification to homogeneity of target regulatory'' enzymes. We have thus developed the necessary background knowledge, based on a firm understanding of enzymology, as well as the necessary experimental tools for studying the regulation of monoterpene metabolism at the molecular level. Furthermore, we are now in a position to extend our systematic approach to other terpenoid classes (C[sub 15]-C[sub 30]) produced by oil glands.

  1. Buck/boost regulator

    Science.gov (United States)

    Paulkovich, J.; Rodriguez, G. E. (Inventor)

    1981-01-01

    A voltage regulated DC to DC converter uses an inductor and a capacitor as storage elements. The inductor is composed of two windings having a common junction. A transformer with a center tap connected to the common junction of the two windings is connected at either end of its winding to ground through controlled switches. One winding of the inductor and either end of the transformer winding are connected by power diodes to the capacitor which supplies the output voltage to a load. The other winding of the inductor is connected to a fourth power diode as a clamping diode. Input voltage is supplied to the inductor through a third controlled switch. A pulse width modulator connected to the output of the converter alternately closes and opens the switches connected to either end of the transformer winding and also closes the switch supplying input voltage to the inductor each time either of the switches connected to the ends of the transformer winding are closed. The duty cycle of the closing and opening of the several switches is adjusted by the pulse modulator to regulate the output voltage.

  2. Regulations and Procedures Manual

    Energy Technology Data Exchange (ETDEWEB)

    Young, Lydia J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2011-07-25

    The purpose of the Regulations and Procedures Manual (RPM) is to provide LBNL personnel with a reference to University and Lawrence Berkeley National Laboratory (LBNL or Laboratory) policies and regulations by outlining normal practices and answering most policy questions that arise in the day-to-day operations of Laboratory organizations. Much of the information in this manual has been condensed from detail provided in LBNL procedure manuals, Department of Energy (DOE) directives, and Contract DE-AC02-05CH11231. This manual is not intended, however, to replace any of those documents. RPM sections on personnel apply only to employees who are not represented by unions. Personnel policies pertaining to employees represented by unions may be found in their labor agreements. Questions concerning policy interpretation should be directed to the LBNL organization responsible for the particular policy. A link to the Managers Responsible for RPM Sections is available on the RPM home page. If it is not clear which organization is responsible for a policy, please contact Requirements Manager Lydia Young or the RPM Editor.

  3. Circadian rhythms regulate amelogenesis.

    Science.gov (United States)

    Zheng, Li; Seon, Yoon Ji; Mourão, Marcio A; Schnell, Santiago; Kim, Doohak; Harada, Hidemitsu; Papagerakis, Silvana; Papagerakis, Petros

    2013-07-01

    Ameloblasts, the cells responsible for making enamel, modify their morphological features in response to specialized functions necessary for synchronized ameloblast differentiation and enamel formation. Secretory and maturation ameloblasts are characterized by the expression of stage-specific genes which follows strictly controlled repetitive patterns. Circadian rhythms are recognized as key regulators of the development and diseases of many tissues including bone. Our aim was to gain novel insights on the role of clock genes in enamel formation and to explore the potential links between circadian rhythms and amelogenesis. Our data shows definitive evidence that the main clock genes (Bmal1, Clock, Per1 and Per2) oscillate in ameloblasts at regular circadian (24 h) intervals both at RNA and protein levels. This study also reveals that the two markers of ameloblast differentiation i.e. amelogenin (Amelx; a marker of secretory stage ameloblasts) and kallikrein-related peptidase 4 (Klk4, a marker of maturation stage ameloblasts) are downstream targets of clock genes. Both, Amelx and Klk4 show 24h oscillatory expression patterns and their expression levels are up-regulated after Bmal1 over-expression in HAT-7 ameloblast cells. Taken together, these data suggest that both the secretory and the maturation stages of amelogenesis might be under circadian control. Changes in clock gene expression patterns might result in significant alterations of enamel apposition and mineralization.

  4. The Quality of Regulation

    Directory of Open Access Journals (Sweden)

    Emil BĂLAN

    2011-11-01

    Full Text Available Good governance also involves the affirmation and practice of some principles that allow the structures of the public space to administrate the general interest in the respect of the democracy and of the state of law pre-requisites, as well as the ones of a good administration: trust and predictability, openness and transparency, responsibility, efficiency and efficacy. The assurance of such desideratum imposes that the rules invested with the force of law, applicable to the juridical rapports to be clear, not equivoques, predictable, to allow both the protection of public interest and the respect of the citizens’ dignity and interests. The evaluation of the quality of regulation represents a necessary process of the appreciation of the impact that juridical norms are intended to produce and measures in which the outcomes of the implementation correspond to the ones established during the stage of formulating the public policy. The study tries to identify ways of evaluating the quality of regulation, valid in a social and political space governed by democratic rules and principles.

  5. Regulations and Procedures Manual

    Energy Technology Data Exchange (ETDEWEB)

    Young, Lydia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2010-09-30

    The purpose of the Regulations and Procedures Manual (RPM) is to provide Laboratory personnel with a reference to University and Lawrence Berkeley National Laboratory policies and regulations by outlining the normal practices and answering most policy questions that arise in the day-to-day operations of Laboratory departments. Much of the information in this manual has been condensed from detail provided in Laboratory procedure manuals, Department of Energy (DOE) directives, and Contract DE-AC02-05CH11231. This manual is not intended, however, to replace any of those documents. The sections on personnel apply only to employees who are not represented by unions. Personnel policies pertaining to employees represented by unions may be found in their labor agreements. Questions concerning policy interpretation should be directed to the department responsible for the particular policy. A link to the Managers Responsible for RPM Sections is available on the RPM home page. If it is not clear which department should be called, please contact the Associate Laboratory Director of Operations.

  6. Regulation as delegation

    Directory of Open Access Journals (Sweden)

    Oren Bar-Gill

    2016-03-01

    Full Text Available Objective to consider the conception of reverse delegation when the government acts a principal and an individual ndash an agent from the point of view of behavioral PrincipalAgent Theory. Methods statistical method sociological polling. Results In diverse areas ndash from retirement savings to consumer credit to prescription drug use to fuel economy and energy efficiency rules to tobacco consumption to food and beverage consumption ndash government makes decisions for us or endeavors to help us make better decisions thus serving as our agent. From the point of view of PrincipalAgent Theory and behavioral PrincipalAgent Theory a great deal of modern regulation can be helpfully evaluated as a hypothetical delegation. Shifting from personal decisions to public goods problems the authors view the idea of reverse delegation with the government as principal and the individuals as agents. They show that the essence of delegation changes depending on the context. The article describes conditions under which various approaches will make sense. Scientific novelty the paper is devoted to the foreign experience of regulation through delegation by the example of a country with developed market economy the USA. It shows the prospects of such approach in solving both the public and the private tasks. Application of PrincipalAgent Theory and behavioral PrincipalAgent Theory is viewed to distinguish between such types of hypothetical delegation as information default rules incentives precommitments mandates and prohibitions. The article considers the benefits and costs of delegation and circumstances in which one or another approach makes sense. Practical significance PrincipalAgent Theory is widely used in economics and political science and can serve as a convenient tool to consider the optimal scale and essence of the assistance rendered to us by the government as our agent. The paper is of interest for the Russian legal science as the institution of

  7. Hormonal Regulators of Appetite

    Directory of Open Access Journals (Sweden)

    Juliana Austin

    2009-01-01

    Full Text Available Obesity is a significant cause of morbidity and mortality worldwide. There has been a significant worsening of the obesity epidemic mainly due to alterations in dietary intake and energy expenditure. Alternatively, cachexia, or pathologic weight loss, is a significant problem for individuals with chronic disease. Despite their obvious differences, both processes involve hormones that regulate appetite. These hormones act on specific centers in the brain that affect the sensations of hunger and satiety. Mutations in these hormones or their receptors can cause substantial pathology leading to obesity or anorexia. Identification of individuals with specific genetic mutations may ultimately lead to more appropriate therapies targeted at the underlying disease process. Thus far, these hormones have mainly been studied in adults and animal models. This article is aimed at reviewing the hormones involved in hunger and satiety, with a focus on pediatrics.

  8. Hormonal Regulators of Appetite

    Directory of Open Access Journals (Sweden)

    Austin Juliana

    2008-11-01

    Full Text Available Obesity is a significant cause of morbidity and mortality worldwide. There has been a significant worsening of the obesity epidemic mainly due to alterations in dietary intake and energy expenditure. Alternatively, cachexia, or pathologic weight loss, is a significant problem for individuals with chronic disease. Despite their obvious differences, both processes involve hormones that regulate appetite. These hormones act on specific centers in the brain that affect the sensations of hunger and satiety. Mutations in these hormones or their receptors can cause substantial pathology leading to obesity or anorexia. Identification of individuals with specific genetic mutations may ultimately lead to more appropriate therapies targeted at the underlying disease process. Thus far, these hormones have mainly been studied in adults and animal models. This article is aimed at reviewing the hormones involved in hunger and satiety, with a focus on pediatrics.

  9. Mitosis and its regulation

    Directory of Open Access Journals (Sweden)

    Frías Vázquez Sara

    2014-07-01

    Full Text Available Cell division by mitosis is essential for the development of organisms and their reproduction; it is also neces- sary that each new cell is genetically identical to that from which it comes. In eukaryotes this is achieved by the presence of complex mechanisms that ensure the integrity of genomic material and their proper segregation during mitosis. The traditional view of mitosis has been divided into different stages that were characterized by morphological studies in dividing cells; advances in molecular biology have led beyond this characterization, so that we now know a range of participant molecules. This article will discuss the process of mitosis, both at the cellular and molecular level and a brief summary of the molecular players that regulate this process.

  10. Meat and Appetite Regulation

    DEFF Research Database (Denmark)

    Kehlet, Ursula Nana

    D thesis was to investigate the effects of fiber addition to meatballs and the effects of cooking methods of pork on appetite regulation. The PhD thesis is based on three human meal test studies and one analytical study related to the characteristics of fiber meat products. In paper I, the objective...... pork products are also characterized as high fat products containing more than 10 g fat per 100 g. In this context, the Danish meat industry puts a lot of effort into developing meat products with a healthier nutritional profile. Thus, it is relevant to provide scientific evidence of the satiating...... effects of new formulations of pork products. Different strategies can be applied to potentially enhance the satiating properties of pork. Processed meat products such as meatballs can serve as a matrix for the addition of fiber ingredients. Based on their high protein and fiber contents, high...

  11. Magnetostrictive Pressure Regulating System

    Science.gov (United States)

    Richard, James A. (Inventor); Pickens, Herman L. (Inventor)

    2013-01-01

    A magnetostrictive pressure regulating system includes a magnetostrictive valve that incorporates a magnetostrictive actuator with at least one current-carrying coil disposed thereabout. A pressure force sensor, in fluid communication with the fluid exiting the valve, includes (i) a magnetostrictive material, (ii) a magnetic field generator in proximity to the magnetostrictive material for inducing a magnetic field in and surrounding the magnetostrictive material wherein lines of magnetic flux passing through the magnetostrictive material are defined, and (iii) a sensor positioned adjacent to the magnetostrictive material and in the magnetic field for measuring changes in at least one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux. The pressure of the fluid exiting the valve causes the applied force. A controller coupled to the sensor and to the current-carrying coil adjusts a current supplied to the current-carrying coil based on the changes so-measured.

  12. NCAM regulates cell motility

    DEFF Research Database (Denmark)

    Prag, Søren; Lepekhin, Eugene A; Kolkova, Kateryna

    2002-01-01

    Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells...... independently of homophilic NCAM interactions. Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment...... to a fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59(fyn) with which NCAM-140 interacts. Furthermore, we showed that the extracellular part of NCAM acted as a paracrine...

  13. Regulation of cholesterol homeostasis.

    Science.gov (United States)

    van der Wulp, Mariëtte Y M; Verkade, Henkjan J; Groen, Albert K

    2013-04-10

    Hypercholesterolemia is an important risk factor for cardiovascular disease. It is caused by a disturbed balance between cholesterol secretion into the blood versus uptake. The pathways involved are regulated via a complex interplay of enzymes, transport proteins, transcription factors and non-coding RNA's. The last two decades insight into underlying mechanisms has increased vastly but there are still a lot of unknowns, particularly regarding intracellular cholesterol transport. After decades of concentration on the liver, in recent years the intestine has come into focus as an important control point in cholesterol homeostasis. This review will discuss current knowledge of cholesterol physiology, with emphasis on cholesterol absorption, cholesterol synthesis and fecal excretion, and new (possible) therapeutic options for hypercholesterolemia.

  14. Regulation of Terpene Metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Rodney Croteau

    2004-03-14

    OAK-B135 Research over the last four years has progressed fairly closely along the lines initially proposed, with progress-driven expansion of Objectives 1, 2 and 3. Recent advances have developed from three research thrusts: 1. Random sequencing of an enriched peppermint oil gland cDNA library has given access to a large number of potential pathway and regulatory genes for test of function; 2. The availability of new DNA probes and antibodies has permitted investigation of developmental regulation and organization of terpenoid metabolism; and 3. The development of a transformation system for peppermint by colleagues at Purdue University has allowed direct transgenic testing of gene function and added a biotechnological component to the project. The current status of each of the original research objectives is outlined below.

  15. Higher regulators, algebraic

    CERN Document Server

    Bloch, Spencer J

    2000-01-01

    This book is the long-awaited publication of the famous Irvine lectures. Delivered in 1978 at the University of California at Irvine, these lectures turned out to be an entry point to several intimately-connected new branches of arithmetic algebraic geometry, such as regulators and special values of L-functions of algebraic varieties, explicit formulas for them in terms of polylogarithms, the theory of algebraic cycles, and eventually the general theory of mixed motives which unifies and underlies all of the above (and much more). In the 20 years since, the importance of Bloch's lectures has not diminished. A lucky group of people working in the above areas had the good fortune to possess a copy of old typewritten notes of these lectures. Now everyone can have their own copy of this classic work.

  16. Probiotics and Appetite Regulation

    DEFF Research Database (Denmark)

    Bjerg, Anne Toksvig

    -armed parallel four weeks intervention study with W8 (1010 CFU) or placebo capsules was performed on young, normal to overweight participants. In the four weeks intervention study the effects of W8 on appetite, blood lipids, SCD1 activity and fecal microbiota were also investigated. Finally, associations between......Summary There is emerging focus on the gut microbiota’s (GM) effects on health. GM is suggested to be a contributing factor to the rapid development of obesity and its related diseases like type 2 diabetes and cardiovascular disease. The omposition of the GM has been associated with weight, insulin...... intestine, in an animal study and in two human studies the effect of the probiotic bacteria Lactobacillus paracasei subsp. paracasei L. casei W8 (W8) on appetite regulation, blood lipids and blood fatty acids. In addition, it was investigated if W8 had an effect on the fecal microbiota of the human...

  17. [Regulation of terpene metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, R.

    1989-11-09

    Terpenoid oils, resins, and waxes from plants are important renewable resources. The objective of this project is to understand the regulation of terpenoid metabolism using the monoterpenes (C[sub 10]) as a model. The pathways of monoterpene biosynthesis and catabolism have been established, and the relevant enzymes characterized. Developmental studies relating enzyme levels to terpene accumulation within the oil gland sites of synthesis, and work with bioregulators, indicate that monoterpene production is controlled by terpene cyclases, the enzymes catalyzing the first step of the monoterpene pathway. As the leaf oil glands mature, cyclase levels decline and monoterpene biosynthesis ceases. Yield then decreases as the monoterpenes undergo catabolism by a process involving conversion to a glycoside and transport from the leaf glands to the root. At this site, the terpenoid is oxidatively degraded to acetate that is recycled into other lipid metabolites. During the transition from terpene biosynthesis to catabolism, the oil glands undergo dramatic ultrastructural modification. Degradation of the producing cells results in mixing of previously compartmentized monoterpenes with the catabolic enzymes, ultimately leading to yield decline. This regulatory model is being applied to the formation of other terpenoid classes (C[sub 15] C[sub 20], C[sub 30], C[sub 40]) within the oil glands. Preliminary investigations on the formation of sesquiterpenes (C[sub 15]) suggest that the corresponding cyclases may play a lesser role in determining yield of these products, but that compartmentation effects are important. From these studies, a comprehensive scheme for the regulation of terpene metabolism is being constructed. Results from this project wail have important consequences for the yield and composition of terpenoid natural products that can be made available for industrial exploitation.

  18. Regulation of melanopsin expression.

    Science.gov (United States)

    Hannibal, Jens

    2006-01-01

    Circadian rhythms in mammals are adjusted daily to the environmental day/night cycle by photic input via the retinohypothalamic tract (RHT). Retinal ganglion cells (RGCs) of the RHT constitute a separate light-detecting system in the mammalian retina used for irradiance detection and for transmission to the circadian system and other non-imaging forming processes in the brain. The RGCs of the RHT are intrinsically photosensitive due to the expression of melanopsin, an opsin-like photopigment. This notion is based on anatomical and functional data and on studies of mice lacking melanopsin. Furthermore, heterologous expression of melanopsin in non-neuronal mammalian cell lines was found sufficient to render these cells photosensitive. Even though solid evidence regarding the function of melanopsin exists, little is known about the regulation of melanopsin gene expression. Studies in albino Wistar rats showed that the expression of melanopsin is diurnal at both the mRNA and protein levels. The diurnal changes in melanopsin expression seem, however, to be overridden by prolonged exposure to light or darkness. Significant increase in melanopsin expression was observed from the first day in constant darkness and the expression continued to increase during prolonged exposure in constant darkness. Prolonged exposure to constant light, on the other hand, decreased melanopsin expression to an almost undetectable level after 5 days of constant light. The induction of melanopsin by darkness was even more pronounced if darkness was preceded by light suppression for 5 days. These observations show that dual mechanisms regulate melanopsin gene expression and that the intrinsic light-responsive RGCs in the albino Wistar rat adapt their expression of melanopsin to environmental light and darkness.

  19. Endocannabinoids in cerebrovascular regulation.

    Science.gov (United States)

    Benyó, Zoltán; Ruisanchez, Éva; Leszl-Ishiguro, Miriam; Sándor, Péter; Pacher, Pál

    2016-04-01

    The cerebral blood flow is tightly regulated by myogenic, endothelial, metabolic, and neural mechanisms under physiological conditions, and a large body of recent evidence indicates that inflammatory pathways have a major influence on the cerebral blood perfusion in certain central nervous system disorders, like hemorrhagic and ischemic stroke, traumatic brain injury, and vascular dementia. All major cell types involved in cerebrovascular control pathways (i.e., smooth muscle, endothelium, neurons, astrocytes, pericytes, microglia, and leukocytes) are capable of synthesizing endocannabinoids and/or express some or several of their target proteins [i.e., the cannabinoid 1 and 2 (CB1 and CB2) receptors and the transient receptor potential vanilloid type 1 ion channel]. Therefore, the endocannabinoid system may importantly modulate the regulation of cerebral circulation under physiological and pathophysiological conditions in a very complex manner. Experimental data accumulated since the late 1990s indicate that the direct effect of cannabinoids on cerebral vessels is vasodilation mediated, at least in part, by CB1 receptors. Cannabinoid-induced cerebrovascular relaxation involves both a direct inhibition of smooth muscle contractility and a release of vasodilator mediator(s) from the endothelium. However, under stress conditions (e.g., in conscious restrained animals or during hypoxia and hypercapnia), cannabinoid receptor activation was shown to induce a reduction of the cerebral blood flow, probably via inhibition of the electrical and/or metabolic activity of neurons. Finally, in certain cerebrovascular pathologies (e.g., subarachnoid hemorrhage, as well as traumatic and ischemic brain injury), activation of CB2 (and probably yet unidentified non-CB1/non-CB2) receptors appear to improve the blood perfusion of the brain via attenuating vascular inflammation.

  20. Standard types of regulation loops; Chaines de regulation types

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, M. [ENSAM, Centre d`Enseignement et de Recherche de Lille, 59 - Lille (France)

    1997-12-01

    The aim of this paper is to give help in the analysis of industrial regulation problems using different types of real installations. The increasing complexity of industrial systems requires the use of a decomposition-recomposition procedure using a scheme with different blocs. Examples are given to help the non-specialist users in the mastery of essential choices and in the distinction between operational and material separations. The examples concern: the heating loop of a central heating installation, the sensors and actuators of industrial systems (the temperature regulation of a tubular furnace, the electro-hydraulic positioning systems used in machine tools, forming, aeronautics etc.., the regulation of a mixing system for hot and cold fluids, and the regulation of a fluidizing system. The usual types of regulation loops are presented with the different steps of the resolution of a regulation problem. (J.S.) 7 refs.

  1. Branded prescription drug fee. Final regulations, temporary regulations, and removal of temporary regulations.

    Science.gov (United States)

    2014-07-28

    This document contains final regulations that provide guidance on the annual fee imposed on covered entities engaged in the business of manufacturing or importing branded prescription drugs. This fee was enacted by section 9008 of the Patient Protection and Affordable Care Act, as amended by section 1404 of the Health Care and Education Reconciliation Act of 2010. This document also withdraws the Branded Prescription Drug Fee temporary regulations and contains new temporary regulations regarding the definition of controlled group that apply beginning on January 1, 2015. The final regulations and the new temporary regulations affect persons engaged in the business of manufacturing or importing certain branded prescription drugs. The text of the temporary regulations in this document also serves as the text of proposed regulations set forth in a notice of proposed rulemaking (REG-123286-14) on this subject in the Proposed Rules section in this issue of the Federal Register.

  2. Regulation of the power sector

    CERN Document Server

    2013-01-01

    Regulation of the Power Sector is a unified, consistent and comprehensive treatment of the theories and practicalities of regulation in modern power-supply systems. The need for generation to occur at the time of use occasioned by the impracticality of large-scale electricity storage coupled with constant and often unpredictable changes in demand make electricity-supply systems large, dynamic and complex and their regulation a daunting task. Conceptually arranged in four parts, this book addresses both traditional regulatory frameworks and also liberalized and re-regulated environments. First, an introduction gives a full characterization of power supply including engineering, economic and regulatory viewpoints. The second part presents the fundamentals of regulation and the third looks at the regulation of particular components of the power sector in detail. Advanced topics and subjects still open or subject to dispute form the content of the fourth part. In a sector where regulatory design is the key driver...

  3. Nanomaterials: Regulation and Risk Assessment

    DEFF Research Database (Denmark)

    Hansen, Steffen Foss; Grieger, Khara Deanne; Baun, Anders

    2013-01-01

    The topics of regulation and risk assessment of nanomaterials have never been more relevant and controversial in Europe than they are at this point in time. In this entry, we present and discuss a number of major pieces of legislation relevant for the regulation of nanomaterials, including REACH...... Regulation. Chemical risk assessment provides a fundamental element in support of existing legislation. Risk assessment is normally said to consist of four elements, i.e., hazard identification, dose–response assessment, exposure assessment, and risk characterization. Each of these four elements hold......, the Water Framework Directive, pharmaceuticals regulation, and the Novel Foods Regulation. Current regulation of nanomaterials entail three overall challenges: 1) limitations in regard to terminology and definitions of key terms such as a “substance,” “novel food,” etc.; 2) safety assessment requirements...

  4. Sustainable regulation of construction.

    Science.gov (United States)

    2000-11-01

    The seminar examined the role building codes and regulations can have in promoting a more sustainable approach to construction, particularly through their application to non-industrial building materials. A range of building materials such as straw, bamboo, rammed earth, adobe, and cob (a mixture of clay and chopped straw) were described and illustrated by slides to show their building potential. The current codes have a prime concern to protect the health and safety of people from the built environment. They have been developed almost exclusively for mainstream industrial materials and methods of construction, which makes them difficult to use with alternative, indigenous, or non-industrial building materials, even though those materials may be considered more sustainable. The argument was put forward that with only one-third of the world population living in modern industrial buildings today, it is not sustainable to re-house the remaining rapidly expanding population in high technology dwellings. Many of the low technology building materials and methods now used by the majority of people in the world need only incremental improvement to be equal or superior to many of their industrial replacements. Since these can be more sustainable methods of building, there needs to be an acceptance of the use of alternative materials, particularly in the developing parts of the world, where they are being rejected for less sustainable industrial methods. However, many codes make it difficult to use non-industrial materials; indeed, many of the industrial materials would not meet the demands that must be now met if they were now being introduced as new materials. Consequently, there is a need to develop codes to facilitate the use of a wider range of materials than in current use, and research is needed to assist this development. Sustainable regulation should take into account the full range of real impacts that materials and systems have in areas such as resource use and

  5. The Structure of Financial Regulation

    OpenAIRE

    Bratu Renate Doina; Petria Nicolae

    2011-01-01

    During the current global financial crisis has called into question the role and objectives of the regulation of financial markets and its scope of action. Liberalization of financial services under the impact of globalization and strong innovative character of the financial system, architecture of regulation has generated a change. In this sense, this paper aims to present and evaluate the structure of financial system regulation in the current international context.

  6. Nitrate Reductase: Properties and Regulation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Nitrate Reductase (NR) is a rating-limit and key enzyme of nitrate assimilation in plants ,so ,NR activity is important for growth,development and the dry matter accumulation of plants. The regulation of NR activity appears to be rather complex and many studies have been devoted to the description of regulation and properties,but in this paper we focus on the properties and regulation of NR in higher plants.

  7. Regulations on Open Government Information

    Institute of Scientific and Technical Information of China (English)

    YOU XUEYUN

    2007-01-01

    @@ On April 24, 2007 the State Council promulgated Regulations of the People's Republic of China on Open Government Information (referred to as Regulations below), which will become effective on May 1, 2008. As the first administrative rule of the central government of China that aims to safeguard the public's right to know, the Regulations are of great significance in China's democratization and its establishment of the rule of law.

  8. Personality and Emotion Regulation Strategies

    Directory of Open Access Journals (Sweden)

    Esti Hayu Purnamaningsih

    2017-01-01

    Full Text Available The emotions has many important functions in our life such as in relation of interpersonal communication, and health. In interpersonal communicative function aimed to signal to other information about internal state. Emotions manifests in specific cognitive, behavioural, and physiological reactions, thus closely related to health. There is wide variety of ways for individuals to regulate their emotion. In this regard, there are two kinds of emotion regulation strategy; first Antecedent-focused emotion regulation consisting of situation selection, situation modification, attentional deployment, cognitive change and second, Response-focused emotion regulation consisting of suppression. The purpose of this research is to investigate personality factors relate with emotion regulation strategies. 339 students from Faculty of Psychology, Universitas Gadjah Mada were participating in this study and given The Big Five Personality Factors (Ramdhani, 2012, adaptation, and the modified version of the Emotion Regulation Scale was used, Emotion Regulation Questionnaire (John & Gross, 2004 which measure personality and emotion regulation respectively. Using multiple regression analysis, the study indicated that personality predicts emotion regulation strategies.

  9. [Ghrelin: beyond hunger regulation].

    Science.gov (United States)

    Milke García, Maria del Pilar

    2005-01-01

    Man ingests food to mitigate hunger (mediated by physiological and biochemical signals), satisfy appetite (subjective sensation) and because of psychosocial reasons. Satiation biomarkers (stop feeding) are gastric distention and hormones (CCK, GLP-1) and satiety biomarkers (induce feeding) are food-induced thermogenesis, body temperature, glycaemia and also hormones (insulin, leptin and ghrelin). Oxidative metabolism/body composition, tryptophan/serotonin and proinflammatory cytokines are also implicated on hunger physiology. At the present time, ghrelin is the only known circulating orexigenic with potential on hunger/body weight regulation. It is a neuropeptide (endogenous ligand for the GH secretagogue) recently isolated from the oxyntic mucosa and synthesized mainly in the stomach. Its blood concentration depends on diet, hyperglucemia and adiposity/leptin. It is secreted 1-2 hours preprandially and its concentration decreases drastically during the postprandium. Ghrelin acts on the lateral hypothalamus and theoretically inhibits proinflammatory cytokine secretion and antagonizes leptin. Ghrelin physiologically increases food intake and stimulates adipogenesis, gastrointestinal motility and gastric acid secretion, and has other hormonal and cardiovascular functions. Ghrelin blood concentration is reduced in massive obesity, non-alcoholic steatohepatitis, polycystic ovary syndrome, acromegaly, hypogonadism, ageing, short bowel syndrome and rheumatoid arthritis; and increased in primary or secondary anorexia, starvation, chronic liver disease and celiac disease. Cerebral and peritoneal ghrelin administration (rats) and systemic administration (rats and healthy volunteers, cancer patients or patients on peritoneal dialysis) promotes food consumption and increases adiposity, of utmost importance in the treatment of patients with anorexia.

  10. Deciphering Transcriptional Regulation

    DEFF Research Database (Denmark)

    Valen, Eivind

    RNA); and ii) translation, in which the mRNA is translated into a protein. This thesis focus on the ¿rst of these steps, transcription, and speci¿cally the initiation of this. Simpli¿ed, initiation is preceded by the binding of several proteins, known as transcription factors (TFs), to DNA. This takes place......The myriad of cells in the human body are all made from the same blueprint: the human genome. At the heart of this diversity lies the concept of gene regulation, the process in which it is decided which genes are used where and when. Genes do not function as on/off buttons, but more like a volume...... control spanning the range from completely muted to cranked up to maximum. The volume, in this case, is the production rate of proteins. This production is the result of a two step procedure: i) transcription, in which a small part of DNA from the genome (a gene) is transcribed into an RNA molecule (an m...

  11. Regulating the sharing economy

    Directory of Open Access Journals (Sweden)

    Kristofer Erickson

    2016-06-01

    Full Text Available In this introductory essay, we explore definitions of the ‘sharing economy’, a concept indicating both social (relational, communitarian and economic (allocative, profit-seeking aspects which appear to be in tension. We suggest combining the social and economic logics of the sharing economy to focus on the central features of network enabled, aggregated membership in a pool of offers and demands (for goods, services, creative expressions. This definition of the sharing economy distinguishes it from other related peer-to-peer and collaborative forms of production. Understanding the social and economic motivations for and implications of participating in the sharing economy is important to its regulation. Each of the papers in this special issue contributes to knowledge by linking the social and economic aspects of sharing economy practices to regulatory norms and mechanisms. We conclude this essay by suggesting future research to further clarify and render intelligible the sharing economy, not as a contradiction in terms but as an empirically observable realm of socio-economic activity.

  12. Epigenetic regulation in obesity.

    Science.gov (United States)

    Drummond, Elaine M; Gibney, Eileen R

    2013-07-01

    Research suggests that 65% of variation in obesity is genetic. However, much of the known genetic associations have little known function and their effect size small, thus the gene-environment interaction, including epigenetic influences on gene expression, is suggested to be an important factor in the susceptibilty to obesity. This review will explore the potential of epigenetic markers to influence expression of genes associated with obesity. Epigenetic changes in utero are known to have direct implications on the phenotype of the offspring. More recently work has focused on how such epigenetic changes continue to regulate risk of obesity from infancy through to adulthood. Work has shown that, for example, hypomethylation of the MC4 gene causes an increase in expression, and has a direct impact on appetite and intake, and thus influences risk of obesity. Similar influences are also seen in other aspects of obesity including inflammation and adiposity. Maternal diet during foetal development has many epigenetic implications, which affect the offspring's risk factors for obesity during childhood and adulthood, and even in subsequent generations. Genes associated with risk of obesity, are susceptible to epigenetic mutations, which have subsequent effects on disease mechanisms, such as appetite and impaired glucose and insulin tolerance.

  13. Regulating regulatory T cells.

    Science.gov (United States)

    Le, N T; Chao, N

    2007-01-01

    Regulatory T cells (Tregs) are a specialized subpopulation of T cells that act to suppress activation of other immune cells and thereby maintain immune system homeostasis, self-tolerance as well as control excessive response to foreign antigens. The mere concept of Tregs was the subject of significant controversy among immunologists for many years owing to the paucity of reliable markers for defining these cells and the ambiguity of the nature and molecular basis of suppressive phenomena. However, recent advances in the molecular characterization of this cell population have firmly established their existence and their vital role in the vertebrate immune system. Of interest, accumulating evidence from both humans and experimental animal models has implicated the involvement of Tregs in the development of graft-versus-host disease (GVHD). The demonstration that Tregs could separate GVHD from graft-versus-tumor (GVT) activity suggests that their immunosuppressive potential could be manipulated to reduce GVHD without detrimental consequence on GVT effect. Although a variety of T lymphocytes with suppressive capabilities have been reported, the two best-characterized subsets are the naturally arising, intrathymic-generated Tregs (natural Tregs) and the peripherally generated, inducible Tregs (inducible Tregs). This review summarizes our current knowledge of the generation, function and regulation of these two populations of Tregs during an immune response. Their role in the development of GVHD and their therapeutic potential for the prevention and treatment of GVHD will also be described.

  14. NCAM regulates cell motility.

    Science.gov (United States)

    Prag, Søren; Lepekhin, Eugene A; Kolkova, Kateryna; Hartmann-Petersen, Rasmus; Kawa, Anna; Walmod, Peter S; Belman, Vadym; Gallagher, Helen C; Berezin, Vladimir; Bock, Elisabeth; Pedersen, Nina

    2002-01-15

    Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells independently of homophilic NCAM interactions. Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment to a fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59(fyn) with which NCAM-140 interacts. Furthermore, we showed that the extracellular part of NCAM acted as a paracrine inhibitor of NCAM-negative cell locomotion through a heterophilic interaction with a cell-surface receptor. As we showed that the two N-terminal immunoglobulin modules of NCAM, which are known to bind to heparin, were responsible for this inhibition, we presume that this receptor is a heparan sulfate proteoglycan. A model for the inhibitory effect of NCAM is proposed, which involves competition between NCAM and extracellular components for the binding to membrane-associated heparan sulfate proteoglycan.

  15. Regulation of sphingomyelin metabolism.

    Science.gov (United States)

    Bienias, Kamil; Fiedorowicz, Anna; Sadowska, Anna; Prokopiuk, Sławomir; Car, Halina

    2016-06-01

    Sphingolipids (SFs) represent a large class of lipids playing diverse functions in a vast number of physiological and pathological processes. Sphingomyelin (SM) is the most abundant SF in the cell, with ubiquitous distribution within mammalian tissues, and particularly high levels in the Central Nervous System (CNS). SM is an essential element of plasma membrane (PM) and its levels are crucial for the cell function. SM content in a cell is strictly regulated by the enzymes of SM metabolic pathways, which activities create a balance between SM synthesis and degradation. The de novo synthesis via SM synthases (SMSs) in the last step of the multi-stage process is the most important pathway of SM formation in a cell. The SM hydrolysis by sphingomyelinases (SMases) increases the concentration of ceramide (Cer), a bioactive molecule, which is involved in cellular proliferation, growth and apoptosis. By controlling the levels of SM and Cer, SMSs and SMases maintain cellular homeostasis. Enzymes of SM cycle exhibit unique properties and diverse tissue distribution. Disturbances in their activities were observed in many CNS pathologies. This review characterizes the physiological roles of SM and enzymes controlling SM levels as well as their involvement in selected pathologies of the Central Nervous System, such as ischemia/hypoxia, Alzheimer disease (AD), Parkinson disease (PD), depression, schizophrenia and Niemann Pick disease (NPD). Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  16. 78 FR 31551 - Federal Acquisition Regulation; Submission for OMB Review; Commerce Patent Regulations

    Science.gov (United States)

    2013-05-24

    ... Regulation; Submission for OMB Review; Commerce Patent Regulations AGENCIES: Department of Defense (DOD... approved information collection requirement concerning Department of Commerce patent regulations. A notice... Collection 9000- 0095, Commerce Patent Regulations, by any of the following methods: Regulations.gov :...

  17. 76 FR 43585 - Bank Secrecy Act Regulations; Definitions and Other Regulations Relating to Money Services...

    Science.gov (United States)

    2011-07-21

    ... Regulations; Definitions and Other Regulations Relating to Money Services Businesses AGENCY: Treasury... Proposed Rulemaking, Definitions and Other Regulations Relating to Money Services Businesses, 74 FR 22129... to the Bank Secrecy Act Regulations-- Definitions and Other Regulations Relating to Money...

  18. Glucocorticoid Regulation of Reproduction.

    Science.gov (United States)

    Geraghty, Anna C; Kaufer, Daniela

    2015-01-01

    It is well accepted that stress, measured by increased glucocorticoid secretion, leads to profound reproductive dysfunction. In times of stress, glucocorticoids activate many parts of the fight or flight response, mobilizing energy and enhancing survival, while inhibiting metabolic processes that are not necessary for survival in the moment. This includes reproduction, an energetically costly procedure that is very finely regulated. In the short term, this is meant to be beneficial, so that the organism does not waste precious energy needed for survival. However, long-term inhibition can lead to persistent reproductive dysfunction, even if no longer stressed. This response is mediated by the increased levels of circulating glucocorticoids, which orchestrate complex inhibition of the entire reproductive axis. Stress and glucocorticoids exhibits both central and peripheral inhibition of the reproductive hormonal axis. While this has long been recognized as an issue, understanding the complex signaling mechanism behind this inhibition remains somewhat of a mystery. What makes this especially difficult is attempting to differentiate the many parts of both of these hormonal axes, and new neuropeptide discoveries in the last decade in the reproductive field have added even more complexity to an already complicated system. Glucocorticoids (GCs) and other hormones within the hypothalamic-pituitary-adrenal (HPA) axis (as well as contributors in the sympathetic system) can modulate the hypothalamic-pituitary-gonadal (HPG) axis at all levels-GCs can inhibit release of GnRH from the hypothalamus, inhibit gonadotropin synthesis and release in the pituitary, and inhibit testosterone synthesis and release from the gonads, while also influencing gametogenesis and sexual behavior. This chapter is not an exhaustive review of all the known literature, however is aimed at giving a brief look at both the central and peripheral effects of glucocorticoids on the reproductive function.

  19. Regulation of gas infrastructure expansion

    NARCIS (Netherlands)

    De Joode, J.

    2012-01-01

    The topic of this dissertation is the regulation of gas infrastructure expansion in the European Union (EU). While the gas market has been liberalised, the gas infrastructure has largely remained in the regulated domain. However, not necessarily all gas infrastructure facilities – such as gas storag

  20. Novel protein regulates ERK pathway

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ The ERK (extracellular signal-regulated kinase) pathway plays a critical role in the vital processes of living cells such as proliferation and differentiation.Recently, CAS scientists in Shanghai have discovered a novel mechanism of spatial regulation on ERK pathway. The result was published in the 4 September issue of the Proceedings of National Academy of Sciences(PNAS).

  1. Regulation of TRPML1 function.

    Science.gov (United States)

    Waller-Evans, Helen; Lloyd-Evans, Emyr

    2015-06-01

    TRPML1 is a ubiquitously expressed cation channel found on lysosomes and late endosomes. Mutations in TRPML1 cause mucolipidosis type IV and it has been implicated in Alzheimer's disease and HIV. However, the mechanisms by which TRPML1 activity is regulated are not well understood. This review summarizes the current understanding of TRPML1 activation and regulation.

  2. Deceptive Business Practices: Federal Regulations.

    Science.gov (United States)

    Rohrer, Daniel Morgan

    Federal regulations to prevent deceptive advertising seek to balance the advertiser's freedom of speech with protection of the consumer. This paper discusses what the Federal Trade Commission (FTC) has done to regulate advertising and evaluates the adequacy of its controls. The commission uses cease-and-desist orders, affirmative disclosure,…

  3. Regulating Pornography: A Public Dilemma.

    Science.gov (United States)

    Thompson, Margaret E.; And Others

    1990-01-01

    Examines attitudes toward sex and pornography by means of a telephone survey of Dane County, Wisconsin, adults. Describes survey questions about sexual attitudes, perceived effects of pornography, and pornography regulation. Concludes that adults who feel more strongly that pornography has negative effects are more opposed to its regulation. (SG)

  4. Frequency-controlled voltage regulator

    Science.gov (United States)

    Mclyman, W. T.

    1980-01-01

    Converting input ac to higher frequency reduce size and weight and makes possible unique kind of regulation. Since conversion frequency is above range of human hearing, supply generated on audible noise. It also exploits highfrequency conversion features to regulate its output voltage in novel way. Circuit is inherently short-circuit proof.

  5. 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

  6. Designing Next Generation Telecom Regulation

    DEFF Research Database (Denmark)

    Henten, Anders; Samarajiva, Rohan

    – ICT convergence regulation and multisector utility regulation. Whatever structure of next generation telecom regulation is adopted, all countries will need to pay much greater attention to the need for increased coordination of policy directions and regulatory activities both across the industries......Continuously expanding applications of information and communication technologies (ICT) are transforming local, national, regional and international economies into network economies, the foundation for information societies. They are being built upon expanded and upgraded national telecom networks...... to creating an environment to foster a massive expansion in the coverage and capabilities of the information infrastructure networks, with national telecom regulators as the key implementers of the policies of reform. The first phase of reform has focused on industry specific telecom policy and regulation...

  7. REGULATION OF NATIONAL QUALIFICATIONS SYSTEMS

    Directory of Open Access Journals (Sweden)

    Anna A. Muravyeva

    2014-01-01

    Full Text Available The paper looks into the diverse aspects of qualifications system regulation, designed for balancing the supply and demand in the labor and educational service markets. Both the objects and mechanisms of such regulation are described. Special attention is given to institutions, involved in regulation of qualifications, and their jurisdiction. Another emphasis is on the industry-related regulation of qualifications which proved to be effective both on the national and European level. Such structures were first established on the national levels to regulate the qualifications and ensure their comparability and compatibility, given the economic globalization and growing labor and academic mobility. The author points out the role of the ministries of education and labor in maintaining a steady qualifications system, and outlines the positive experience of Great Britain using the industry councils for continuing development of qualifications system.

  8. Regulation of GMOs in China.

    Science.gov (United States)

    Liu, Yinliang

    2008-12-01

    Genetically modified organisms (GMOs) are created by biotechnology to serve people with much benefit while may impose risks to ecological environment and human health and therefore need careful regulation. During the past two decades, GMOs have been well developed in China and so has their corresponding regulation. This paper reviews and comments the multiple aspects of mainly the agricultural GMOs, including their safety assessment, control measures, trade activities, import, labels, and GM food, which have been prescribed by the corresponding laws, regulations and administrative measures. It is held that till present a framework for regulation of agricultural GMOs and GM food has been established basically in China, while a more comprehensive system for regulation of all kinds of GMOs and all kinds of related activities is still needed at present and in the future.

  9. RNA-guided transcriptional regulation

    Energy Technology Data Exchange (ETDEWEB)

    Church, George M.; Mali, Prashant G.; Esvelt, Kevin M.

    2016-02-23

    Methods of modulating expression of a target nucleic acid in a cell are provided including introducing into the cell a first foreign nucleic acid encoding one or more RNAs complementary to DNA, wherein the DNA includes the target nucleic acid, introducing into the cell a second foreign nucleic acid encoding a nuclease-null Cas9 protein that binds to the DNA and is guided by the one or more RNAs, introducing into the cell a third foreign nucleic acid encoding a transcriptional regulator protein or domain, wherein the one or more RNAs, the nuclease-null Cas9 protein, and the transcriptional regulator protein or domain are expressed, wherein the one or more RNAs, the nuclease-null Cas9 protein and the transcriptional regulator protein or domain co-localize to the DNA and wherein the transcriptional regulator protein or domain regulates expression of the target nucleic acid.

  10. Designing Next Generation Telecom Regulation

    DEFF Research Database (Denmark)

    Henten, Anders; Samarajiva, Rohan; Melody, William H.

    2003-01-01

    to the regulatory process such as scarcity of regulatory resources and safeguards for regulatory independence, are examined. It is concluded that ICT and media convergence issues are primarily about improving the efficiency of market economies, and how changes in regulation can facilitate this process. Multi......This article critically examines the multiple rationales for telecom, IT, media convergence regulation, on the one hand, and multisector utility regulation, on the other, and the practical questions of implementation they pose, with a view to contributing to informed policy and regulatory decisions....... Both options involve substantive as well as procedural issues, not necessarily separable. The conditions that may affect the creation of convergence and multi-sector regulation, ranging from underlying commonality of inputs and the behaviour of regulated firms to considerations that are specific...

  11. AGROCHEMICALS GROWTH REGULATORS ON ALFALFA

    Directory of Open Access Journals (Sweden)

    Buldykova I. A.

    2015-04-01

    Full Text Available One of the methods of increasing the productivity of alfalfa is the use of growth regulators, and the use of polymeric compositions of growth regulators, binders with synthesized growth regulators of sim-triazine series is promising with the possibility of creating environmentally friendly technologies for growing alfalfa. Studies have shown that the application of the test on alfalfa growth regulators has a positive effect on growth, physiological and morphogenetic processes, plant resistance to adverse environmental conditions. Intensity impact on plant growth regulators depends on the type of plant growth regulators, concentration and method of application. Processing alfalfa seed growth regulators on germination increases energy 3,0-14,0 % germination on 8,0-17,0 %. Processing plant growth regulators to enhance the growth of plants in height (on the 7th day – 2,6-11,9 % , on the 14th 41,9-48,0 % , the growth of aboveground biomass , expands on the number of productive branches of the 1st ( 24,1-41,3 % and 2nd order (21,7-55,0 %. Pre-sowing seed treatment and plant growth regulators alfalfa sim- triazine series contributed to the increase in seed yield of 15,5 %. On average, the yield of green mass increased by 0,8-2,4 t /ha or 5,2-15,5 % and seed yield at 0,19-0,42 h/ha or 8,7-19, 3 %. Growth regulators of sim-triazine series increase the protein content of the vegetative mass of alfalfa at 3,2-4,6 %

  12. Regulated electricity retailing in Chile

    Energy Technology Data Exchange (ETDEWEB)

    Galetovic, Alexander, E-mail: alexander@galetovic.cl [Facultad de Ciencias Economicas y Empresariales, Universidad de los Andes, Santiago, Chile. Av. San Carlos de Apoquindo 2200, Las Condes, Santiago (Chile); Munoz, Cristian M., E-mail: cmunozm@aes.com [AES Gener and Departamento de Ingenieria Electrica, Universidad Catolica de Chile (Chile)

    2011-10-15

    While some countries have unbundled distribution and retailing, skeptics argue that the physical attributes of electricity make retailers redundant. Instead, it is claimed that passive pass through of wholesale prices plus regulated charges for transmission and distribution suffice for customers to benefit from competitive generation markets. We review the Chilean experience with regulated retailing and pass through of wholesale prices. We argue that when energy wholesale prices are volatile and prices are stabilized, distortions emerge. Regulated retailers gain little by mitigating or correcting them. On the contrary, sometimes price distortions increase their profits. We estimate the cost of three distortions that neither regulated retailers nor the regulator have shown any interest in correcting. - Highlights: > We review Chile's experience with regulated electricity retailing. > Distortions emerge when energy wholesale prices are volatile and prices stabilized. > Regulated retailers gain little by mitigating or correcting distortions. > Sometimes price distortions increase retailers' profits. > We estimate the cost of three distortions, which retailers have not corrected.

  13. Mental fatigue impairs emotion regulation.

    Science.gov (United States)

    Grillon, Christian; Quispe-Escudero, David; Mathur, Ambika; Ernst, Monique

    2015-06-01

    Because healthy physical and mental functioning depends on the ability to regulate emotions, it is important to identify moderators of such regulations. Whether mental fatigue, subsequent to the depletion of cognitive resources, impairs explicit emotion regulation to negative stimuli is currently unknown. This study explored this possibility. In a within-subject design over 2 separate sessions, healthy individuals performed easy (control session) or difficult (depletion session) cognitive tasks. Subsequently, they were presented with neutral and negative pictures, with instructions to either maintain or regulate (i.e., reduce) the emotions evoked by the pictures. Emotional reactivity was probed with the startle reflex. The negative pictures evoked a similar aversive state in the control and depletion sessions as measured by startle potentiation. However, subjects were able to down-regulate their aversive state only in the control session, not in the depletion session. These results indicate that mental fatigue following performance of cognitive tasks impairs emotion regulation without affecting emotional reactivity. These findings suggest that mental fatigue needs to be incorporated into models of emotion regulation.

  14. Grandfather regulations, new source bias, and state air toxics regulations

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, Arik [University of Wisconsin Economics Department, 1180 Observatory Drive, Madison, WI 53706 (United States)

    1999-02-01

    This paper uses plant-level data from the Census of Manufactures and the variation in toxic air pollution regulations across states to measure the effects of laws that are more stringent for new sources of pollution than for existing sources (so-called `grandfather` regulations). Of particular interest is the resulting `new source bias` and its effects on capital vintage and investment. Two industries are examined: commercial printing, which has a local product market; and paint manufacturing, which has a more national market. In general, there seem to be no statistically significant differences in capital vintage or investment between plants in states that grandfather new sources of pollution, plants in states that have no air toxics regulations, and plants in states that regulate both new and existing sources

  15. The regulation of ascorbate biosynthesis.

    Science.gov (United States)

    Bulley, Sean; Laing, William

    2016-10-01

    We review the regulation of ascorbate (vitamin C) biosynthesis, focusing on the l-galactose pathway. We discuss the regulation of ascorbate biosynthesis at the level of gene transcription (both repression and enhancement) and translation (feedback inhibition of translation by ascorbate concentration) and discuss the eight proteins that have been demonstrated to date to affect ascorbate concentration in plant tissues. GDP-galactose phosphorylase (GGP) and GDP-mannose epimerase are critical steps that regulate ascorbate biosynthesis. These and other biosynthetic genes are controlled at the transcriptional level, while GGP is also controlled at the translational level. Ascorbate feedback on enzyme activity has not been observed unequivocally.

  16. Emotional regulation strategies and negotiation.

    Science.gov (United States)

    Yurtsever, Gülçimen

    2004-12-01

    This study examined the relationship between profit achievement and emotional regulation strategies, using Kelley's Negotiation Game to measure profit achievement. The game involves bargaining for the prices of three products. Emotional Regulation Strategies were measured by The Emotional Regulation Questionnaire. Scores were obtained from 104 lower level managers of a bank in Turkey. Their average age was 32.0 yr. (SD=3.7), (39 women and 65 men). A correlation of .65 (p<.01) was obtained between scores on profit achievement with scores on Cognitive Reappraisal strategy and -.50 (p<.01) with scores on Suppression strategy.

  17. Nanometrology - challenges for health regulation

    Directory of Open Access Journals (Sweden)

    Jailton Carreteiro Damasceno

    2013-11-01

    Full Text Available The relationship between metrology, nanotechnology and nanoscience and sanitary regulation is discussed from the point of view of its importance and the interrelationship between the themes for the development of products and services involving nanotech-nology. The discussion involves the main techniques for measuring dimensional, chemical and biological properties of materials, and presents some of the challenges for the future. Issues such as processes of standardization and regulation in Europe, U.S. and Brazil are also addressed, providing an overview of how these processes are related to sanitary regulation.

  18. Voltage Regulators for Photovoltaic Systems

    Science.gov (United States)

    Delombard, R.

    1986-01-01

    Two simple circuits developed to provide voltage regulation for highvoltage (i.e., is greater than 75 volts) and low-voltage (i.e., is less than 36 volts) photovoltaic/battery power systems. Use of these circuits results in voltage regulator small, low-cost, and reliable, with very low power dissipation. Simple oscillator circuit controls photovoltaic-array current to regulate system voltage and control battery charging. Circuit senses battery (and system) voltage and adjusts array current to keep battery voltage from exceeding maximum voltage.

  19. The regulation of climate engineering

    NARCIS (Netherlands)

    Reynolds, J.L.

    2011-01-01

    Intentional interventions in global physical, chemical, and biological systems on a massive scale are receiving increasing attention in hopes of reducing the threat of anthropogenic climate change. Known as climate engineering, or geoengineering, research is moving forward, but regulation remains

  20. Assessing self-regulation strategies

    DEFF Research Database (Denmark)

    de Vet, Emely; de Ridder, Denise T. D.; Stok, Marijn

    2014-01-01

    Background: Applying self-regulation strategies have proven important in eating behaviors, but it remains subject to investigation what strategies adolescents report to use to ensure healthy eating, and adequate measures are lacking. Therefore, we developed and validated a self...... participants were aged between 10 and 17 years. Results: Study 1 resulted in a 24-item questionnaire assessing adolescent-reported use of six specific strategies for healthy eating that represent three general self-regulation approaches. Study 2 showed that the easy-to-administer theory-based TESQ-E has...... general self-regulation and motivation measures. Conclusions: The TESQ-E provides a reliable and valid measure to assess six theory-based self-regulation strategies that adolescents may use to ensure their healthy eating....

  1. Electronic Code of Federal Regulations

    Data.gov (United States)

    National Archives and Records Administration — The Electronic Code of Federal Regulations (e-CFR) is the codification of the general and permanent rules published in the Federal Register by the executive...

  2. Network Regulation and Support Schemes

    DEFF Research Database (Denmark)

    Ropenus, Stephanie; Schröder, Sascha Thorsten; Jacobsen, Henrik

    2009-01-01

    -in tariffs to market-based quota systems, and network regulation approaches, comprising rate-of-return and incentive regulation. National regulation and the vertical structure of the electricity sector shape the incentives of market agents, notably of distributed generators and network operators....... This article seeks to investigate the interactions between the policy dimensions of support schemes and network regulation and how they affect the deployment of distributed generation. Firstly, a conceptual analysis examines how the incentives of the different market agents are affected. In particular......, it will be shown that there frequently exists a trade-off between the creation of incentives for distributed generators and for distribution system operators to facilitate the integration of distributed generation. Secondly, the interaction of these policy dimensions is analyzed, including case studies based...

  3. Regulation of TAZ in cancer

    Directory of Open Access Journals (Sweden)

    Xin Zhou

    2016-07-01

    Full Text Available ABSTRACT TAZ, a transcriptional coactivator with PDZ-binding motif, is encoded by WWTR1 gene (WW domain containing transcription regulator 1. TAZ is tightly regulated in the hippo pathway-dependent and -independent manner in response to a wide range of extracellular and intrinsic signals, including cell density, cell polarity, F-actin related mechanical stress, ligands of G protein-coupled receptors (GPCRs, cellular energy status, hypoxia and osmotic stress. Besides its role in normal tissue development, TAZ plays critical roles in cell proliferation, differentiation, apoptosis, migration, invasion, epithelial-mesenchymal transition (EMT, and stemness in multiple human cancers. We discuss here the regulators and regulation of TAZ. We also highlight the tumorigenic roles of TAZ and its potential therapeutic impact in human cancers.

  4. Comparison of some European regulations

    Energy Technology Data Exchange (ETDEWEB)

    Argyriadis, K. [Germanisher Lloyd, Hamburg (Germany)

    1996-09-01

    Fatigue calculations are an essential part in certification of a wind turbine. Manufacturers have to fulfill recommendations of several different regulations throughout Europe with the result that the design has often to be altered to satisfy them. In general three national (D/GL, NL, DK), and two international (GL, IEC) regulations are in use, with the IEC standard getting more importance with wind energy deploying to more in regions with no yet clearly defined national standards (India, Spain). The Germanischer Lloyd made calculations for wind turbines they are certifying and in one case we compared the resulting damages for different regulations and classes on a 600 kW, three bladed, stall regulated wind turbine. (EG) 18 refs.

  5. Network Regulation and Support Schemes

    DEFF Research Database (Denmark)

    Ropenus, Stephanie; Schröder, Sascha Thorsten; Jacobsen, Henrik

    2009-01-01

    -in tariffs to market-based quota systems, and network regulation approaches, comprising rate-of-return and incentive regulation. National regulation and the vertical structure of the electricity sector shape the incentives of market agents, notably of distributed generators and network operators....... This article seeks to investigate the interactions between the policy dimensions of support schemes and network regulation and how they affect the deployment of distributed generation. Firstly, a conceptual analysis examines how the incentives of the different market agents are affected. In particular......, it will be shown that there frequently exists a trade-off between the creation of incentives for distributed generators and for distribution system operators to facilitate the integration of distributed generation. Secondly, the interaction of these policy dimensions is analyzed, including case studies based...

  6. Ways of standardizing mining regulations

    Energy Technology Data Exchange (ETDEWEB)

    Macionga, R.

    1990-07-01

    Deals with ways of improving and standardizing mining regulations in Poland. Shortcomings of existing mining regulations and legal rules are discussed, their main disadvantage being their great multitude and variety. Apart from institutional faults there are also constitutional failures, e.g. exaggerated safety requirements. Another weakness of the existing regulations is the terminology used that is not compatible with standardized mining terminology. Conversion of all regulations, directions and legal acts into standards is recommended as the best means of improvement and the best methods of standarization are suggested. The standards should be issued by only one institution which should be the Higher Mining Office. Establishing Higher and District Mining Offices as the only control structures and a standarized mining law is postulated.

  7. 7 CFR 29.29 - Regulations.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Regulations. 29.29 Section 29.29 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Regulations Definitions § 29.29 Regulations. Rules and regulations of the Secretary under the Act....

  8. 7 CFR 987.48 - Container regulation.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Container regulation. 987.48 Section 987.48... IN RIVERSIDE COUNTY, CALIFORNIA Order Regulating Handling Container Regulation § 987.48 Container regulation. Whenever the Committee deems it advisable to establish a container regulation for any variety...

  9. Civilsamfundets ABC: R for Regulering

    DEFF Research Database (Denmark)

    Meyer, Gitte; Lund, Anker Brink

    2016-01-01

    Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til R for Regulering.......Hvad er civilsamfundet? Anker Brink Lund og Gitte Meyer fra CBS Center for Civil Society Studies gennemgår civilsamfundet bogstav for bogstav. Vi er nået til R for Regulering....

  10. Self Regulating Fiber Fuel Cell

    Science.gov (United States)

    2010-08-16

    energy numbers are 2.3X and 5.7X the theoretical values for lithium thionyl chloride respectively (1100 Whr/liter and 590 Whr/kg), which has the...REPORT Self Regulating Fiber Fuel Cell 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: Advances in lithium primary battery technology, which serves as the...Prescribed by ANSI Std. Z39.18 - 16-Aug-2010 Self Regulating Fiber Fuel Cell Report Title ABSTRACT Advances in lithium primary battery technology

  11. Labour's Record on Financial Regulation

    OpenAIRE

    Daripa, Arup; Kapur, Sandeep; Wright, Stephen

    2013-01-01

    In 1997 the new Labour government launched major initiatives in the area of financial regulation, setting up the Financial Services Authority as a comprehensive regulatory body, supported by the legislative framework of the Financial Services and Markets Act 2000. We evaluate the Labour government’s record on financial regulation in terms of its achievements and failures, especially in dealing with the global financial crisis that started in 2007. While we identify some clear flaws in regulat...

  12. Money Laundering and its Regulation

    OpenAIRE

    Alberto E. Chong; Florencio López-de-Silanes

    2007-01-01

    The recent wave of terrorist attacks has increased the attention paid to money laundering activities. Using several methodologies, this paper investigates empirically the determinants of money laundering and its regulation in over 80 countries by assembling a cross-country dataset on proxies for money laundering and the prevalence of feeding activities. The paper additionally constructs specific money laundering regulation indices based on available information on laws and their mechanisms of...

  13. Mycotoxins – Limits and Regulations

    OpenAIRE

    2001-01-01

    Since early years, a need has always been felt for some control on the quality of foodstuffs. With the discovery of aflatoxins in the early sixties, health authorities in man countries have become active in establishing regulations to protect their citizens and livestock fro t potential harm caused by mycotoxins. FDA mycotox-ins-in-foods sampling program is continuing with an objective to remove those foods from interstate commerce that contain Aflatoxins “at levels judged to be of regulator ...

  14. Money Laundering and its Regulation

    OpenAIRE

    Alberto E. Chong; Florencio López-de-Silanes

    2007-01-01

    The recent wave of terrorist attacks has increased the attention paid to money laundering activities. Using several methodologies, this paper investigates empirically the determinants of money laundering and its regulation in over 80 countries by assembling a cross-country dataset on proxies for money laundering and the prevalence of feeding activities. The paper additionally constructs specific money laundering regulation indices based on available information on laws and their mechanisms of...

  15. PERIPHERAL MECHANISMS IN APPETITE REGULATION

    OpenAIRE

    Camilleri, Michael

    2014-01-01

    Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide inpu...

  16. Assessing self-regulation strategies

    DEFF Research Database (Denmark)

    de Vet, Emely; de Ridder, Denise T. D.; Stok, Marijn

    2014-01-01

    Background: Applying self-regulation strategies have proven important in eating behaviors, but it remains subject to investigation what strategies adolescents report to use to ensure healthy eating, and adequate measures are lacking. Therefore, we developed and validated a self-regulation questio......Background: Applying self-regulation strategies have proven important in eating behaviors, but it remains subject to investigation what strategies adolescents report to use to ensure healthy eating, and adequate measures are lacking. Therefore, we developed and validated a self...... participants were aged between 10 and 17 years. Results: Study 1 resulted in a 24-item questionnaire assessing adolescent-reported use of six specific strategies for healthy eating that represent three general self-regulation approaches. Study 2 showed that the easy-to-administer theory-based TESQ-E has...... general self-regulation and motivation measures. Conclusions: The TESQ-E provides a reliable and valid measure to assess six theory-based self-regulation strategies that adolescents may use to ensure their healthy eating....

  17. Emotion regulation and sport performance.

    Science.gov (United States)

    Wagstaff, Christopher R D

    2014-08-01

    This study used a single-blind, within-participant, counterbalanced, repeated-measures design to examine the relationship between emotional self-regulation and sport performance. Twenty competitive athletes completed four laboratory-based conditions; familiarization, control, emotion suppression, and nonsuppression. In each condition participants completed a 10-km cycling time trial requiring self-regulation. In the experimental conditions participants watched an upsetting video before performing the cycle task. When participants suppressed their emotional reactions to the video (suppression condition) they completed the cycling task slower, generated lower mean power outputs, and reached a lower maximum heart rate and perceived greater physical exertion than when they were given no self-regulation instructions during the video (nonsuppression condition) and received no video treatment (control condition). The findings suggest that emotional self-regulation resource impairment affects perceived exertion, pacing and sport performance and extends previous research examining the regulation of persistence on physical tasks. The results are discussed in line with relevant psychophysiological theories of self-regulation and fatigue and pertinent potential implications for practice regarding performance and well-being are suggested.

  18. Precision Adjustable Liquid Regulator (ALR)

    Science.gov (United States)

    Meinhold, R.; Parker, M.

    2004-10-01

    A passive mechanical regulator has been developed for the control of fuel or oxidizer flow to a 450N class bipropellant engine for use on commercial and interplanetary spacecraft. There are several potential benefits to the propulsion system, depending on mission requirements and spacecraft design. This system design enables more precise control of main engine mixture ratio and inlet pressure, and simplifies the pressurization system by transferring the function of main engine flow rate control from the pressurization/propellant tank assemblies, to a single component, the ALR. This design can also reduce the thermal control requirements on the propellant tanks, avoid costly Qualification testing of biprop engines for missions with more stringent requirements, and reduce the overall propulsion system mass and power usage. In order to realize these benefits, the ALR must meet stringent design requirements. The main advantage of this regulator over other units available in the market is that it can regulate about its nominal set point to within +/-0.85%, and change its regulation set point in flight +/-4% about that nominal point. The set point change is handled actively via a stepper motor driven actuator, which converts rotary into linear motion to affect the spring preload acting on the regulator. Once adjusted to a particular set point, the actuator remains in its final position unpowered, and the regulator passively maintains outlet pressure. The very precise outlet regulation pressure is possible due to new technology developed by Moog, Inc. which reduces typical regulator mechanical hysteresis to near zero. The ALR requirements specified an outlet pressure set point range from 225 to 255 psi, and equivalent water flow rates required were in the 0.17 lb/sec range. The regulation output pressure is maintained at +/-2 psi about the set point from a P (delta or differential pressure) of 20 to over 100 psid. Maximum upstream system pressure was specified at 320 psi

  19. Regulation Development for Drinking Water Contaminants

    Science.gov (United States)

    To explain what process and information underlies regulations including how the Safe Drinking Water Act applies to regulation development i.e. how does the drinking water law translate into regulations.

  20. 77 FR 43082 - Federal Acquisition Regulation; Information Collection; Commerce Patent Regulations

    Science.gov (United States)

    2012-07-23

    ... Regulation; Information Collection; Commerce Patent Regulations AGENCIES: Department of Defense (DOD... approved information collection requirement concerning Department of Commerce patent regulations. Public...: Submit comments identified by Information Collection 9000- 0095, Commerce Patent Regulations, by any...

  1. Balancing Public and Private Regulation

    Directory of Open Access Journals (Sweden)

    Martijn Scheltema

    2016-01-01

    Full Text Available Voluntary Sustainability Standards (VSS might develop into a viable alternative to public regulation. However, it turns on the (regulatory circumstances whether that holds true in practice. If public regulation on CSR topics is lacking, governments are unable to agree upon certain topics on a global level or diverging public regulation exists, VSS can be helpful to set global standards. Obviously, private standards will especially be helpful if they are commensurate with local public legislation (and e.g. treaties and/or are accepted by local governments. If one neglects this, numerous domestic structures might exist that frustrate VSS. Furthermore, governments have to remain vigilant as to whether these private regimes do not result in market disruption, consumer detriment or hamper trade. VSS might also compete with public arrangements which might limit the uptake of VSS. However, if public regulation exists VSS might be a viable alternative if compliance with not too compelling public norms by market participants is rather poor and the public policymaker is aiming to incentivize the better performing part of the market to embark on higher standards and thus only desires to regulate the less performing part of the market. However, of paramount importance is the effectiveness of VSS in order to be a viable alternative to public regulation. The effectiveness of VSS should be assessed using an integrated multi-disciplinary (comparative approach entailing legal, impact-assessment, legitimacy, governance and behavioural aspects. Only effective VSS in the aforementioned sense are a true alternative to public regulation.Beyond that, the legal perspective in connection with (the effectiveness of VSS is discussed, featuring FSC and UTZ Certified as an example. It is important from this perspective that VSS have a clear and sufficiently selective objective and sufficiently specific norms, are regularly evaluated, entail ‘conflict of law rules’ and

  2. To Regulate or Not to Regulate? Views on Electronic Cigarette Regulations and Beliefs about the Reasons for and against Regulation.

    Science.gov (United States)

    Sanders-Jackson, Ashley; Tan, Andy S L; Bigman, Cabral A; Mello, Susan; Niederdeppe, Jeff

    2016-01-01

    Policies designed to restrict marketing, access to, and public use of electronic cigarettes (e-cigarettes) are increasingly under debate in various jurisdictions in the US. Little is known about public perceptions of these policies and factors that predict their support or opposition. Using a sample of US adults from Amazon Mechanical Turk in May 2015, this paper identifies beliefs about the benefits and costs of regulating e-cigarettes and identifies which of these beliefs predict support for e-cigarette restricting policies. A higher proportion of respondents agreed with 8 different reasons to regulate e-cigarettes (48.5% to 83.3% agreement) versus 7 reasons not to regulate e-cigarettes (11.5% to 18.9%). The majority of participants agreed with 7 out of 8 reasons for regulation. When all reasons to regulate or not were included in a final multivariable model, beliefs about protecting people from secondhand vapor and protecting youth from trying e-cigarettes significantly predicted stronger support for e-cigarette restricting policies, whereas concern about government intrusion into individual choices was associated with reduced support. This research identifies key beliefs that may underlie public support or opposition to policies designed to regulate the marketing and use of e-cigarettes. Advocates on both sides of the issue may find this research valuable in developing strategic campaigns related to the issue. Specific beliefs of potential benefits and costs of e-cigarette regulation (protecting youth, preventing exposure to secondhand vapor, and government intrusion into individual choices) may be effectively deployed by policy makers or health advocates in communicating with the public.

  3. Thyroid Hormone Regulation of Metabolism

    Science.gov (United States)

    Mullur, Rashmi; Liu, Yan-Yun

    2014-01-01

    Thyroid hormone (TH) is required for normal development as well as regulating metabolism in the adult. The thyroid hormone receptor (TR) isoforms, α and β, are differentially expressed in tissues and have distinct roles in TH signaling. Local activation of thyroxine (T4), to the active form, triiodothyronine (T3), by 5′-deiodinase type 2 (D2) is a key mechanism of TH regulation of metabolism. D2 is expressed in the hypothalamus, white fat, brown adipose tissue (BAT), and skeletal muscle and is required for adaptive thermogenesis. The thyroid gland is regulated by thyrotropin releasing hormone (TRH) and thyroid stimulating hormone (TSH). In addition to TRH/TSH regulation by TH feedback, there is central modulation by nutritional signals, such as leptin, as well as peptides regulating appetite. The nutrient status of the cell provides feedback on TH signaling pathways through epigentic modification of histones. Integration of TH signaling with the adrenergic nervous system occurs peripherally, in liver, white fat, and BAT, but also centrally, in the hypothalamus. TR regulates cholesterol and carbohydrate metabolism through direct actions on gene expression as well as cross-talk with other nuclear receptors, including peroxisome proliferator-activated receptor (PPAR), liver X receptor (LXR), and bile acid signaling pathways. TH modulates hepatic insulin sensitivity, especially important for the suppression of hepatic gluconeogenesis. The role of TH in regulating metabolic pathways has led to several new therapeutic targets for metabolic disorders. Understanding the mechanisms and interactions of the various TH signaling pathways in metabolism will improve our likelihood of identifying effective and selective targets. PMID:24692351

  4. Balancing Public and Private Regulation

    Directory of Open Access Journals (Sweden)

    Martijn Scheltema

    2016-01-01

    Full Text Available Voluntary Sustainability Standards (VSS might develop into a viable alternative to public regulation. However, it turns on the (regulatory circumstances whether that holds true in practice. If public regulation on CSR topics is lacking, governments are unable to agree upon certain topics on a global level or diverging public regulation exists, VSS can be helpful to set global standards. Obviously, private standards will especially be helpful if they are commensurate with local public legislation (and e.g. treaties and/or are accepted by local governments. If one neglects this, numerous domestic structures might exist that frustrate VSS. Furthermore, governments have to remain vigilant as to whether these private regimes do not result in market disruption, consumer detriment or hamper trade. VSS might also compete with public arrangements which might limit the uptake of VSS. However, if public regulation exists VSS might be a viable alternative if compliance with not too compelling public norms by market participants is rather poor and the public policymaker is aiming to incentivize the better performing part of the market to embark on higher standards and thus only desires to regulate the less performing part of the market. However, of paramount importance is the effectiveness of VSS in order to be a viable alternative to public regulation. The effectiveness of VSS should be assessed using an integrated multi-disciplinary (comparative approach entailing legal, impact-assessment, legitimacy, governance and behavioural aspects. Only effective VSS in the aforementioned sense are a true alternative to public regulation.Beyond that, the legal perspective in connection with (the effectiveness of VSS is discussed, featuring FSC and UTZ Certified as an example. It is important from this perspective that VSS have a clear and sufficiently selective objective and sufficiently specific norms, are regularly evaluated, entail ‘conflict of law rules’ and

  5. Drinking Water Contaminants -- Standards and Regulations

    Science.gov (United States)

    ... Protection Agency Search Search Contact Us Share Drinking Water Contaminants – Standards and Regulations EPA identifies contaminants to regulate in drinking water to protect public health. The ...

  6. Regulation of Autophagy by Kinases

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Savitha; Jain, Kirti; Basu, Alakananda, E-mail: alakananda.basu@unthsc.edu [Department of Molecular Biology and Immunology, Institute for Cancer Research, University of North Texas Health Science Center, Fort Worth, TX 76107 (United States)

    2011-06-09

    Autophagy is a process of self-degradation that maintains cellular viability during periods of metabolic stress. Although autophagy is considered a survival mechanism when faced with cellular stress, extensive autophagy can also lead to cell death. Aberrations in autophagy are associated with several diseases, including cancer. Therapeutic exploitation of this process requires a clear understanding of its regulation. Although the core molecular components involved in the execution of autophagy are well studied there is limited information on how cellular signaling pathways, particularly kinases, regulate this complex process. Protein kinases are integral to the autophagy process. Atg1, the first autophagy-related protein identified, is a serine/threonine kinase and it is regulated by another serine/threonine kinase mTOR. Emerging studies suggest the participation of many different kinases in regulating various components/steps of this catabolic process. This review focuses on the regulation of autophagy by several kinases with particular emphasis on serine/threonine protein kinases such as mTOR, AMP-activated protein kinase, Akt, mitogen-activated protein kinase (ERK, p38 and JNK) and protein kinase C that are often deregulated in cancer and are important therapeutic targets.

  7. Cosmetic Regulations: A Comparative Study.

    Science.gov (United States)

    Suhag, Jyoti; Dureja, Harish

    2015-01-01

    The regulatory framework, compliance requirement, efficacy, safety, and marketing of cosmetic products are considered the most important factors for growth of the cosmetic industry. There are different regulatory bodies across the globe that have their own insights for regulation; moreover, governments such as the United States, European Union, and Japan follow a stringent regulatory framework, whereas cosmetics are not so much strictly regulated in countries such as India, Brazil, and China. The alignment of a regulatory framework will play a significant role in the removal of barriers to trade, growth of market at an international level, innovation in the development and presentation of new products, and most importantly safety and efficacy of the marketed products. The present contribution gives insight into the important cosmetic regulations in areas of premarket approval, ingredient control, and labeling and warnings, with a special focus on the cosmetic regulatory environments in the United States, European Union, Japan, and India. Most importantly, the authors highlight the dark side of cosmetics associated with allergic reactions and even skin cancer. The importance of cosmetic regulations has been highlighted by dint of which the society can be healthier, accomplished by more stringent and harmonized regulations.

  8. Progress toward risk informed regulation

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, K.C.

    1997-01-01

    For the last several years, the NRC, with encouragement from the industry, has been moving in the direction of risk informed regulation. This is consistent with the regulatory principle of efficiency, formally adopted by the Nuclear Regulatory Commission in 1991, which requires that regulatory activities be consistent with the degree of risk reduction they achieve. Probabilistic risk analysis has become the tool of choice for selecting the best of several alternatives. Closely related to risk informed regulation is the development of performance based rules. Such rules focus on the end result to be achieved. They do not specify the process, but instead establish the goals to be reached and how the achievement of those goals is to be judged. The inspection and enforcement activity is based on whether or not the goals have been met. The author goes on to offer comments on the history of the development of this process and its probable development in the future. He also addresses some issues which must be resolved or at least acknowledged. The success of risk informed regulation ultimately depends on having sufficiently reliable data to allow quantification of regulatory alternatives in terms of relative risk. Perhaps the area of human reliability and organizational performance has the greatest potential for improvement in reactor safety. The ability to model human performance is significantly less developed that the ability to model mechanical or electrical systems. The move toward risk informed, performance based regulation provides an unusual, perhaps unique, opportunity to establish a more rational, more effective basis for regulation.

  9. Digital Convergence and Content Regulation

    Directory of Open Access Journals (Sweden)

    Michael John Starks

    2014-12-01

    Full Text Available Broadcasting, Press and Internet journalism systems of distribution are converging: the same infrastructure can deliver all three historically separate services. Reception devices mirror this: the Connected TV, the tablet and the smart phone overlap in their functionality. Service overlaps are evident too, with broadcasters providing online and on-demand services and newspapers developing electronic versions. Does this mean that media regulation policies must converge too?My argument is that they should, though only where historically different communications are now fulfilling a similar function, e.g. broadcaster online services and electronic versions of newspapers. Convergence requires a degree of harmonisation and, to this end, I advocate a review of UK broadcasting's 'due impartiality' requirement and of the UK's application of the public service concept. I also argue for independent self-regulation (rather than state-based regulation of non-public-service broadcasting journalism.

  10. Guidelines on Building Regulations 2008

    DEFF Research Database (Denmark)

    Thse guidelines clarify and intepret the provisions of the Building Regulations of 2008 (BR08). The Guidelines, which match BR08 in terms of organisation into Parts, are accompanied by the full text of the regulations and the explanatory notes issued by the Danish Enterprise and Construction...... Authority. The Guidelines refer the reader to sources such as relevant standards, instructions and other background material which provides more detailed information. The Guidelines cover the same ground as BR08, including building control regulations, layout, fitting out, structures, fire safety, indoor...... climate, energy consumotion and services. The Guidelines are aimed at all professionals involved in building projects, particularly building design consultants, contractors and municipal application officers....

  11. Circadian Regulation of Macronutrient Absorption.

    Science.gov (United States)

    Hussain, M Mahmood; Pan, Xiaoyue

    2015-12-01

    Various intestinal functions exhibit circadian rhythmicity. Disruptions in these rhythms as in shift workers and transcontinental travelers are associated with intestinal discomfort. Circadian rhythms are controlled at the molecular level by core clock and clock-controlled genes. These clock genes are expressed in intestinal cells, suggesting that they might participate in the circadian regulation of intestinal functions. A major function of the intestine is nutrient absorption. Here, we will review absorption of proteins, carbohydrates, and lipids and circadian regulation of various transporters involved in their absorption. A better understanding of circadian regulation of intestinal absorption might help control several metabolic disorders and attenuate intestinal discomfort associated with disruptions in sleep-wake cycles.

  12. Upstream regulation of mycotoxin biosynthesis.

    Science.gov (United States)

    Alkhayyat, Fahad; Yu, Jae-Hyuk

    2014-01-01

    Mycotoxins are natural contaminants of food and feed products, posing a substantial health risk to humans and animals throughout the world. A plethora of filamentous fungi has been identified as mycotoxin producers and most of these fungal species belong to the genera Aspergillus, Fusarium, and Penicillium. A number of studies have been conducted to better understand the molecular mechanisms of biosynthesis of key mycotoxins and the regulatory cascades controlling toxigenesis. In many cases, the mycotoxin biosynthetic genes are clustered and regulated by one or more pathway-specific transcription factor(s). In addition, as biosynthesis of many secondary metabolites is coordinated with fungal growth and development, there are a number of upstream regulators affecting biosynthesis of mycotoxins in fungi. This review presents a concise summary of the regulation of mycotoxin biosynthesis, focusing on the roles of the upstream regulatory elements governing biosynthesis of aflatoxin and sterigmatocystin in Aspergillus.

  13. Molecular regulation of osteoclast activity.

    Science.gov (United States)

    Bruzzaniti, Angela; Baron, Roland

    2006-06-01

    Osteoclasts are multinucleated cells derived from hematopoietic precursors that are primarily responsible for the degradation of mineralized bone during bone development, homeostasis and repair. In various skeletal disorders such as osteoporosis, hypercalcemia of malignancy, tumor metastases and Paget's disease, bone resorption by osteoclasts exceeds bone formation by osteoblasts leading to decreased bone mass, skeletal fragility and bone fracture. The overall rate of osteoclastic bone resorption is regulated either at the level of differentiation of osteoclasts from their monocytic/macrophage precursor pool or through the regulation of key functional proteins whose specific activities in the mature osteoclast control its attachment, migration and resorption. Thus, reducing osteoclast numbers and/or decreasing the bone resorbing activity of osteoclasts are two common therapeutic approaches for the treatment of hyper-resorptive skeletal diseases. In this review, several of the key functional players involved in the regulation of osteoclast activity will be discussed.

  14. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  15. Nutritional regulation of fetal growth.

    Science.gov (United States)

    Bloomfield, Frank H; Jaquiery, Anne L; Oliver, Mark H

    2013-01-01

    Fetal growth is largely regulated by nutritional supply. The placenta is responsible for fetal nutrient supply for much of pregnancy, but in early pregnancy nutrition is histiotrophic. Both placental size and efficiency, and fetal growth, may be affected by maternal nutritional state before and during very early pregnancy. In contrast, manipulating maternal nutrition during later stages of pregnancy has a smaller than expected effect on fetal growth. Maternal nutrition before and during early pregnancy also has a greater effect on gestation length than maternal nutrition later in pregnancy, suggesting that nutritional status may regulate both fetal growth trajectory and gestation length and that these two outcomes may be linked. Thus, determination of the nutritional factors regulating fetal growth, and potentially postnatal growth and body phenotype, may lie with the maternal nutritional status even before conception.

  16. Positively regulated bacterial expression systems.

    Science.gov (United States)

    Brautaset, Trygve; Lale, Rahmi; Valla, Svein

    2009-01-01

    Regulated promoters are useful tools for many aspects related to recombinant gene expression in bacteria, including for high-level expression of heterologous proteins and for expression at physiological levels in metabolic engineering applications. In general, it is common to express the genes of interest from an inducible promoter controlled either by a positive regulator or by a repressor protein. In this review, we discuss established and potentially useful positively regulated bacterial promoter systems, with a particular emphasis on those that are controlled by the AraC-XylS family of transcriptional activators. The systems function in a wide range of microorganisms, including enterobacteria, soil bacteria, lactic bacteria and streptomycetes. The available systems that have been applied to express heterologous genes are regulated either by sugars (L-arabinose, L-rhamnose, xylose and sucrose), substituted benzenes, cyclohexanone-related compounds, ε-caprolactam, propionate, thiostrepton, alkanes or peptides. It is of applied interest that some of the inducers require the presence of transport systems, some are more prone than others to become metabolized by the host and some have been applied mainly in one or a limited number of species. Based on bioinformatics analyses, the AraC-XylS family of regulators contains a large number of different members (currently over 300), but only a small fraction of these, the XylS/Pm, AraC/P(BAD), RhaR-RhaS/rhaBAD, NitR/PnitA and ChnR/Pb regulator/promoter systems, have so far been explored for biotechnological applications.

  17. Medical device regulation for manufacturers.

    Science.gov (United States)

    McAllister, P; Jeswiet, J

    2003-01-01

    Manufacturers of medical devices are held to a higher standard than manufacturers of many other products due to the potential severity of the consequences of introducing inferior or unsafe products to the market-place. In Canada, the medical device industry is regulated by Health Canada under the Medical Device Regulations of the Food and Drug Act. The Medical Device Regulations define requirements of medical device design, development and manufacture to ensure that products reaching the public are safe and effective. Health Canada also requires that medical device manufacturers maintain distribution records to ensure that devices can be traced to the source and consumers can be contacted successfully in the event that a device is recalled. Medical devices exported from Canada must be compliant with the regulations of the country of import. The Canadian Medical Device Regulations were based on the Medical Device Directives of the European Union thus facilitating approval of Canadian devices for the European market. The United States Food and Drug Administration has separate and distinct requirements for safety and quality of medical devices. While effort has been made to facilitate approval and trade of Canadian medical devices in the United States and the European Union, obtaining approval from multiple regulatory bodies can result in increased device development time and cost. The Global Harmonization Task Force is an organization composed of members from Japanese, Australian, European, Canadian and American medical device regulatory bodies. This organization was formed with the objective of harmonizing medical device regulations in an effort to facilitate international trade and standardize the quality of medical devices available to all countries. This paper discusses the requirements that must be met by manufacturers when designing and manufacturing medical devices.

  18. Autoimmune regulator, Aire, is a novel regulator of chondrocyte differentiation.

    Science.gov (United States)

    Si, Yuan; Inoue, Kazuki; Igarashi, Katsuhide; Kanno, Jun; Imai, Yuuki

    2013-08-09

    Chondrocyte differentiation is controlled by various regulators, such as Sox9 and Runx2, but the process is complex. To further understand the precise underlying molecular mechanisms of chondrocyte differentiation, we aimed to identify a novel regulatory factor of chondrocyte differentiation using gene expression profiles of micromass-cultured chondrocytes at different differentiation stages. From the results of microarray analysis, the autoimmune regulator, Aire, was identified as a novel regulator. Aire stable knockdown cells, and primary cultured chondrocytes obtained from Aire(-/-) mice, showed reduced mRNA expression levels of chondrocyte-related genes. Over-expression of Aire induced the early stages of chondrocyte differentiation by facilitating expression of Bmp2. A ChIP assay revealed that Aire was recruited on an Airebinding site (T box) in the Bmp2 promoter region in the early stages of chondrocyte differentiation and histone methylation was modified. These results suggest that Aire can facilitate early chondrocyte differentiation by expression of Bmp2 through altering the histone modification status of the promoter region of Bmp2. Taken together, Aire might play a role as an active regulator of chondrocyte differentiation, which leads to new insights into the regulatory mechanisms of chondrocyte differentiation. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Transcription regulation mechanisms of bacteriophages

    Science.gov (United States)

    Yang, Haiquan; Ma, Yingfang; Wang, Yitian; Yang, Haixia; Shen, Wei; Chen, Xianzhong

    2014-01-01

    Phage diversity significantly contributes to ecology and evolution of new bacterial species through horizontal gene transfer. Therefore, it is essential to understand the mechanisms underlying phage-host interactions. After initial infection, the phage utilizes the transcriptional machinery of the host to direct the expression of its own genes. This review presents a view on the transcriptional regulation mechanisms of bacteriophages, and its contribution to phage diversity and classification. Through this review, we aim to broaden the understanding of phage-host interactions while providing a reference source for researchers studying the regulation of phage transcription. PMID:25482231

  20. Wave Dragon Buoyancy Regulation Study

    DEFF Research Database (Denmark)

    Jakobsen, Jens; Kofoed, Jens Peter

    Wave Dragon is a wave energy converter, which was deployed offshore at Nissum Bredning in Denmark in 2003. The experience gained from operating Wave Dragon during 2003 and 2004 has shown that the buoyancy regulation system can be improved in a number of ways. This study describes the current situ...... situation, and proposes a number of activities in order to improve the buoyancy regulation system. This work was performed under EU ENERGIE contract no. ENK5-CT-2002-00603, and is a contribution to WP 2.3/2.4 and D40/D41....

  1. Regulating Power from Supermarket Refrigeration

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Madsen, Henrik; Pinson, Pierre

    2014-01-01

    This paper presents an analysis of the demand response capabilities of a supermarket refrigeration system, with a particular focus on the suitability for participation in the regulating power market. An ARMAX model of a supermarket refrigeration system is identified using experimental data from...... nature of demand response from refrigeration is identified as the key consideration when considering participation in the regulating power market. It is demonstrated that by restricting the operating regions of the supermarket refrigeration system, a simple relationship can be found between the available...

  2. Regulation of Francisella tularensis Virulence

    Directory of Open Access Journals (Sweden)

    Shipan eDai

    2011-01-01

    Full Text Available Francisella tularensis is one of the most virulent bacteria known and a Centers for Disease Control and Prevention Category A select agent. It is able to infect a variety of animals and insects and can persist in the environment, thus Francisella spp. must be able to survive in diverse environmental niches. However, F. tularensis has a surprising dearth of sensory and regulatory factors. Recent advancements in the field have identified new functions of encoded transcription factors and greatly expanded our understanding of virulence gene regulation. Here we review the current knowledge of environmental adaptation by F. tularensis, its transcriptional regulators and their relationship to animal virulence.

  3. Limited Regulation of Lake Erie.

    Science.gov (United States)

    1983-11-01

    Ontario,, Cedar Point in Ohio, Presque Isle in Pennsylvania and Hamlin in New York. Recreational boating is a significant activity on Lake Erie . Along...RD-Al47 936 LIMITED REGULATION OF LAKE ERIE (U) INTERNATIONAL LAKE i/i ERIE REGULATION STUDY BOARD NOV 83 UNCLASSIFIED F/G 13/2 N lhhhhh..hEmhhI...o lake Erie ’Governmen of 4,- % * L CTE " 84100400 .- Canad Unite Stte INTRNAIONL OIN COMISIO 4WD’ This document hais been ow for public rleoe and so

  4. TWEAK Negatively Regulates Human Dicer

    OpenAIRE

    2016-01-01

    The ribonuclease Dicer plays a central role in the microRNA pathway by processing microRNA precursors (pre-microRNAs) into microRNAs, a class of 19- to 24-nucleotide non-coding RNAs that regulate expression of ≈60% of the genes in humans. To gain further insights into the function and regulation of Dicer in human cells, we performed a yeast two-hybrid (Y2HB) screen using human Dicer double-stranded RNA-binding domain (dsRBD) as bait. This approach identified tumor necrosis factor (TNF)-like w...

  5. Epigenetic regulation in cardiac fibrosis

    Institute of Scientific and Technical Information of China (English)

    Li-Ming; Yu; Yong; Xu

    2015-01-01

    Cardiac fibrosis represents an adoptive response in the heart exposed to various stress cues. While resolution of the fibrogenic response heralds normalization of heart function, persistent fibrogenesis is usually associated with progressive loss of heart function and eventually heart failure. Cardiac fibrosis is regulated by a myriad of factors that converge on the transcription of genes encoding extracellular matrix proteins, a process the epigenetic machinery plays a pivotal role. In this minireview, we summarize recent advances regarding the epigenetic regulation of cardiac fibrosis focusing on the role of histone and DNA modifications and non-coding RNAs.

  6. Politics of public utility regulation

    Energy Technology Data Exchange (ETDEWEB)

    Gormley, W.T. Jr.

    1983-01-01

    Since the early 1970s, energy and telecommunications policies have emerged as increasingly complex and conflictual issues in state government and have, consequently, brought about change in the politics of public utilities regulation. In this analysis, Gormley shows that state public utilities commissions, in determining the rates that can be charged by private utility companies, must confront elected government officials, members of the state bureaucracy, citizens' groups, and the regulated industries themselves in a very visible, highly technical, costly, and controversial process that pits investors against consumers, business groups against residential consumers, consumer groups against environmentalists, and low-income consumers against consumers as a whole.

  7. Teaching Students To Regulate Their Own Behavior.

    Science.gov (United States)

    Johnson, Lewis R.; Johnson, Christine E.

    1999-01-01

    Offers strategies for teaching students in all grades self-regulation skills for the purposes of behavior change. Discusses the importance of facilitating generalization, components of self-regulation, steps of self-regulation, selecting a target behavior, graphing and record keeping, and benefits and potential of teaching self-regulation skills.…

  8. Liquidity regulation and bank behavior

    NARCIS (Netherlands)

    Bonner, C.

    2014-01-01

    In response to the 2007-08 financial crisis, the Basel Committee on Banking Supervision proposed two liquidity standards to reinforce banks’ resilience to liquidity risks. The purpose of this thesis is to analyze the impact of liquidity regulation on bank behavior. The first of four main chapters

  9. Liquidity regulation and bank behavior

    NARCIS (Netherlands)

    Bonner, C.

    2014-01-01

    In response to the 2007-08 financial crisis, the Basel Committee on Banking Supervision proposed two liquidity standards to reinforce banks’ resilience to liquidity risks. The purpose of this thesis is to analyze the impact of liquidity regulation on bank behavior. The first of four main chapters an

  10. Regulating Collaboration in Teacher Education

    Science.gov (United States)

    Dobber, Marjolein; Akkerman, Sanne F.; Verloop, Nico; Vermunt, Jan D.

    2014-01-01

    Collaboration in teacher education can be seen as a way to prepare student teachers for future social practices at school. When people collaborate with each other, they have to regulate their collaboration. In the Dutch teacher education programme that was investigated, student teachers were members of different types of groups, each of which had…

  11. Incentives and regulation in banking

    NARCIS (Netherlands)

    Martynova, N.

    2015-01-01

    The financial crisis of 2007-2008 has unveiled the hidden flaws in the regulatory framework of the financial sector. The rules of the game established by regulators were not stringent enough and provided bankers with wrong incentives to gamble with depositors’ money. There are two major challenges i

  12. Temperature: Human Regulating, Ants Conforming

    Science.gov (United States)

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  13. Deceptive Business Practices: State Regulations.

    Science.gov (United States)

    Rohrer, Daniel Morgan

    Although much has been done at the federal level to control deceptive advertising practices, many states have no criminal laws designed to regulate advertising, and several states recently repealed such laws. This paper examines states' efforts to balance the advertiser's freedom of speech with the consumer's need for information about products by…

  14. Wave Dragon Buoyancy Regulation Study

    DEFF Research Database (Denmark)

    Jakobsen, Jens; Kofoed, Jens Peter

    Wave Dragon is a wave energy converter, which was deployed offshore at Nissum Bredning in Denmark in 2003. The experience gained from operating Wave Dragon during 2003 and 2004 has shown that the buoyancy regulation system can be improved in a number of ways. This study describes the current...

  15. Bed Bug Laws and Regulations

    Science.gov (United States)

    21 states have some level of regulation with regard to bed bugs. Most of these requirements focus on hotels and landlords or other property managers. The Department of Housing and Urban Development has guidance on controlling bed bugs in public housing.

  16. Emotion regulation and successful aging.

    Science.gov (United States)

    Suri, Gaurav; Gross, James J

    2012-08-01

    Despite normative declines in old age, healthy elderly typically report surprisingly high levels of well-being. It is not clear why this is so. A study by Brassen and colleagues suggests that one factor may be reduced responsiveness to regret. These findings highlight the role of emotion regulation in successful aging.

  17. Histaminergic regulation of prolactin secretion

    DEFF Research Database (Denmark)

    Knigge, U P

    1990-01-01

    of DA synthesis and of DA or serotonin (5-HT) receptors inhibit or prevent the PRL stimulatory action of HA infused centrally or systemically. However, other factors regulating PRL secretion (e.g. beta-endorphin, vasoactive intestinal peptide, vasopressin or TRH) may be involved in the mediation...

  18. Phytochrome-regulated Gene Expression

    Institute of Scientific and Technical Information of China (English)

    Peter H. Quail

    2007-01-01

    Identification of all genes involved in the phytochrome (phy)-mediated responses of plants to their light environment is an important goal in providing an overall understanding of light-regulated growth and development. This article highlights and integrates the central findings of two recent comprehensive studies in Arabidopsis that have identified the genome-wide set of phy-regulated genes that respond rapidly to red-light signals upon first exposure of dark-grown seedlings, and have tested the functional relevance to normal seedling photomorphogenesis of an initial subset of these genes. The data: (a) reveal considerable complexity in the channeling of the light signals through the different phy-family members (phyA to phyE) to responsive genes; (b) identify a diversity of transcription-factor-encoding genes as major early, if not primary, targets of phy signaling, and, therefore, as potentially important regulators in the transcriptional-network hierarchy; and (c) identify auxin-related genes as the dominant class among rapidly-regulated, hormone-related genes. However, reverse-genetic functional profiling of a selected subset of these genes reveals that only a limited fraction are necessary for optimal phy-induced seedling deetiolation.

  19. Allosteric regulation of phenylalanine hydroxylase.

    Science.gov (United States)

    Fitzpatrick, Paul F

    2012-03-15

    The liver enzyme phenylalanine hydroxylase is responsible for conversion of excess phenylalanine in the diet to tyrosine. Phenylalanine hydroxylase is activated by phenylalanine; this activation is inhibited by the physiological reducing substrate tetrahydrobiopterin. Phosphorylation of Ser16 lowers the concentration of phenylalanine for activation. This review discusses the present understanding of the molecular details of the allosteric regulation of the enzyme.

  20. Allosteric Regulation of Phenylalanine Hydroxylase

    OpenAIRE

    Fitzpatrick, Paul F.

    2011-01-01

    The liver enzyme phenylalanine hydroxylase is responsible for conversion of excess phenylalanine in the diet to tyrosine. Phenylalanine hydroxylase is activated by phenylalanine; this activation is inhibited by the physiological reducing substrate tetrahydrobiopterin. Phosphorylation of Ser16 lowers the concentration of phenylalanine for activation. This review discusses the present understanding of the molecular details of the allosteric regulation of the enzyme.

  1. Spatial regulation of Rap signaling

    NARCIS (Netherlands)

    Gloerich, M.

    2011-01-01

    By cycling between an inactive GDP-bound and active GTP-bound state, small G-proteins of the Rap family act as molecular switches that relay upstream signals to diverse cellular processes. This GDP/GTP-cycle and consequently downstream signaling by Rap is under tight regulation by its GEFs and GAPs.

  2. Bank regulation and banking stability

    NARCIS (Netherlands)

    Boot, A.; Thakor, A.V.

    2014-01-01

    This note discusses some issues in bank closure policy from a financial stability standpoint and how these issues have evolved since we first raised the question of how a reputation-driven divergence of interests between bank regulators and taxpayers may distort bank closure policy in our 1993 paper

  3. Temperature: Human Regulating, Ants Conforming

    Science.gov (United States)

    Clopton, Joe R.

    2007-01-01

    Biological processes speed up as temperature rises. Procedures for demonstrating this with ants traveling on trails, and data gathered by students on the Argentine ant ("Linepithema humile") are presented. The concepts of temperature regulation and conformity are detailed with a focus on the processes rather than on terms that label the organisms.

  4. The regulation of climate engineering

    NARCIS (Netherlands)

    Reynolds, J.L.

    2011-01-01

    Intentional interventions in global physical, chemical, and biological systems on a massive scale are receiving increasing attention in hopes of reducing the threat of anthropogenic climate change. Known as climate engineering, or geoengineering, research is moving forward, but regulation remains in

  5. The Organization of Regulated Production

    DEFF Research Database (Denmark)

    Jansen, Jos; Jeon, Doh-Shin; Menicucci, Domenico

    2008-01-01

    and weak positive (respectively, strong positive) correlation. Second, if the firms can collude under VS and know all costs, then VS is equivalent to VI. However, if firms collude under asymmetric information, then collusion does not affect the choice between VS and VI, since the regulator takes advantage...... of the transaction costs created by asymmetric information....

  6. The Legal Regulation of Cybersecurity

    Directory of Open Access Journals (Sweden)

    Darius Štitilis

    2013-08-01

    Full Text Available Cybercrime has become a global phenomenon, which is causing more harm to individual citizens, organizations, society and the state. Most countries in the world compare cybercrime with offences such as terrorism and drug trafficking due to its risks and profitability. Cybersecurity is the central category to fight cybercrime in cyberspace. Therefore, the strategic legal regulation of cybersecurity is one of the most relevant problems in EU, including Lithuania. So far cybersecurity legal regulation analysis in scientific literature has been rather limited. The European Commission, together with the High Representative of the Union for Foreign Affairs and Security Policy, has published a cybersecurity strategy alongside a Commission proposed directive on network and information security (NIS. The cybersecurity strategy – “An Open, Safe and Secure Cyberspace” - represents the EU’s comprehensive vision on how best to prevent and respond to cyber disruptions and attacks. The purpose of its is to further European values of freedom and democracy and ensure the digital economy can safely grow. Specific actions are aimed at enhancing cyber resilience of information systems, reducing cybercrime and strengthening EU international cyber-security policy and cyber defence. The main goal of the paper is to analyze and compare the EU cybersecurity strategy and experience of several foreign countries with the strategic legal regulation of cybersecurity in Lithuania. The article consists of four parts. The first part dealt with the EU cybersecurity strategy. The second part of the article examines the comparative aspect of foreign cybersecurity strategic legal regulation. The third part deals with attempts in Lithuania to draft cybersecurity law and the holistic approach of cybersecurity legal regulation. The fourth part examines Lithuanian cybersecurity strategy and comments on the main probleas related with the strategy. Several different approaches

  7. Regulation of the fungal secretome.

    Science.gov (United States)

    McCotter, Sean W; Horianopoulos, Linda C; Kronstad, James W

    2016-08-01

    The ability of countless representatives of the Kingdom Fungi to adapt to and proliferate in diverse environments is facilitated by regulation of their secretomes to respond to changes in environmental conditions and to mediate interactions with other organisms. Secretome changes often fulfill common functions of nutrient acquisition, facilitation of host/symbiont interactions, cell wall modification, and optimization of the enzyme suite to adapt to new environmental resources. In this review, we expand on our recent work on signaling and the secretome in the pathogenic fungus Cryptococcus neoformans to consider a range of selected examples of regulation of fungal secretomes. These examples include the impact of carbon source and aspects of the response to plant and animal hosts. Additionally, the influence of key protein kinases (e.g., Pka1, Snf1) and transcription factors (e.g., Rim101/PacC) is highlighted to illustrate some underlying regulatory factors influencing the secretome. Although there is a wealth of information about fungal secretomes from both experimentation and genome sequence mining, there are also major gaps in our knowledge about the complete composition of fungal secretomes and mechanisms of dynamic change. For example, a more comprehensive understanding of the composition and regulation of the secretome will require consideration of the emerging roles of unconventional secretion and extracellular vesicles in delivering proteins outside the cell. Overall, changes in the secretome are well documented in diverse fungi and the underlying mechanisms are currently under investigation; however, there remain unknown steps in the regulation of secretory pathways and gaps in understanding the regulation of unconventional secretion, which warrant further research.

  8. 呼吸代谢调控桃果实采后抗氧化活性研究进展%Progress on Antioxidant Capacity of Postharvest Peach Fruit Regulated by Respiratory Metabolism

    Institute of Scientific and Technical Information of China (English)

    梁敏华; 杨震峰; 陈伟; 苏新国

    2013-01-01

    Respiratory metabolism is one of the most important physiological activities of posthavest climacteric fruit, and is also closely related to the biosynthesis of different bioactive compounds. This paper concluded the effect of respiratory metabolism on the biosynthesis and metabolism of antioxidant composition ( such as phenolic acid, flavonol, flavan-3-ol, anthocyanin and carotenoids) and key enzymes expressions in postharvest peach fruit of different varieties ( Red-flesh, Yellow-flesh, and White-flesh) . Based on investigations from the respiration pathway, the paper also discussed the specific mechanism of respiratory metabolism involved in the biosynthesis of such antioxidant compounds, expounded the molecular basis of the biosynthetic pathway and regulation of key enzymes of flavonoids and carotenoids, and clearifed the role and regulation of storage environmental conditions on the antioxdiant properties and antioxidant compounds of harvested fruits during storage. These would provide theoretical basis for regulation of antioxidant compounds metabolism and finally improve the nutritional quality in postharvest fruits.%桃果实为典型的跃变型果实,需要经历呼吸跃变才能成熟可食。呼吸代谢是跃变型果实采后重要的生理活动之一,与果实采后抗氧化物质的形成存在密切的联系。本文从桃果实采后呼吸跃变生理入手,总结了桃果实采后主要酚酸、黄酮醇、黄烷-3-醇、花色苷和类胡萝卜素消长的规律,并进一步从桃果实采后呼吸代谢中间产物及关键酶与上述次生物质代谢关键酶的基因表达水平探讨呼吸代谢对果实采后抗氧化能力的影响作用,明确呼吸代谢在桃果实采后抗氧化活性过程中的可能作用机制。

  9. Natural Gas Distribution Regulation Natural Gas Distribution Regulation

    Directory of Open Access Journals (Sweden)

    Fernando Salas

    1995-03-01

    Full Text Available This document discusses the economic content of a set of Ruling affecting the provision of natural gas distribution services in Mexico. As such, it describes the mechanisms proposed in order to ensure economic efficiency in the undertaking of such activity, i.e., competition policies, rate regulation, delimination of licensed geographic regions and design of auction procedures for the granting of distribution franchises. This document discusses the economic content of a set of Ruling affecting the provision of natural gas distribution services in Mexico. As such, it describes the mechanisms proposed in order to ensure economic efficiency in the undertaking of such activity, i.e., competition policies, rate regulation, delimination of licensed geographic regions and design of auction procedures for the granting of distribution franchises.

  10. REGULATION OF INTESTINAL DYSBACTERIOSIS OF BURNED RATS BY MICROECOSYSTEM REGULATORS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To investigate the feasibility of using synbiotics and probiotics to prevent and cure intestinal dysbacteriosis after burn. Methods Burned rats were fed with synbiotics and probiotics reagents, and the amounts of major intestinal florae in caecal contents were detected. Results The major physiological anaerobes were mostly stable, and the conditioned pathogens had no abnormal. Conclusion The micro-ecosystem regulator can quickly supplement the decreased physiological anaerobes caused by burning,and avoid the occurrence of dysbacteriosis.

  11. Microtubule affinity-regulating kinase 4: structure, function, and regulation.

    Science.gov (United States)

    Naz, Farha; Anjum, Farah; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

    2013-11-01

    MAP/Microtubule affinity-regulating kinase 4 (MARK4) belongs to the family of serine/threonine kinases that phosphorylate the microtubule-associated proteins (MAP) causing their detachment from the microtubules thereby increasing microtubule dynamics and facilitating cell division, cell cycle control, cell polarity determination, cell shape alterations, etc. The MARK4 gene encodes two alternatively spliced isoforms, L and S that differ in their C-terminal region. These isoforms are differentially regulated in human tissues including central nervous system. MARK4L is a 752-residue-long polypeptide that is divided into three distinct domains: (1) protein kinase domain (59-314), (2) ubiquitin-associated domain (322-369), and (3) kinase-associated domain (703-752) plus 54 residues (649-703) involved in the proper folding and function of the enzyme. In addition, residues 65-73 are considered to be the ATP-binding domain and Lys88 is considered as ATP-binding site. Asp181 has been proposed to be the active site of MARK4 that is activated by phosphorylation of Thr214 side chain. The isoform MARK4S is highly expressed in the normal brain and is presumably involved in neuronal differentiation. On the other hand, the isoform MARK4L is upregulated in hepatocarcinoma cells and gliomas suggesting its involvement in cell cycle. Several biological functions are also associated with MARK4 including microtubule bundle formation, nervous system development, and positive regulation of programmed cell death. Therefore, MARK4 is considered as the most suitable target for structure-based rational drug design. Our sequence, structure- and function-based analysis should be helpful for better understanding of mechanisms of regulation of microtubule dynamics and MARK4 associated diseases.

  12. Regulating regulator y T cells to achieve transplant tolerance

    Institute of Scientific and Technical Information of China (English)

    Ran Tao; Wayne W. Hancock

    2007-01-01

    BACKGROUND:Regulatory T cells (Tregs) play crucial roles in both induction and maintenance of tolerance. This active immune regulation may contribute not only to the control of immune responses to self-antigens and thereby prevent autoimmune diseases, but also the control of responses to non-self molecules in adaptive immunity. Numerous experimental and clinical studies indicate that manipulating the balance between regulatory and responder T cells is an effective strategy to control immune responsiveness after transplantation. DATA SOURCES:Literature search was conducted using PubMed on the related subjects. Part of the material was based on the most recent work in the authors' laboratory. RESULTS: We propose some new strategies to achieve transplant tolerance in rodent animals via manipulating Treg function, including using histone deacetylase (HDAC) inhibitor to regulate Foxp3 transcription and enhance Treg suppression, induction of Treg-sparing apoptosis via Nur77, and identiifcation of the co-inhibitory molecule herpes virus entry mediator (HVEM) as an effector molecule for Treg function. CONCLUSION:Regulation of Treg function will deifnitely provide us very promising tools to achieve clinical tolerance in the future.

  13. Targeted genome regulation via synthetic programmable transcriptional regulators

    KAUST Repository

    Piatek, Agnieszka Anna

    2016-04-19

    Regulation of gene transcription controls cellular functions and coordinates responses to developmental, physiological and environmental cues. Precise and efficient molecular tools are needed to characterize the functions of single and multiple genes in linear and interacting pathways in a native context. Modular DNA-binding domains from zinc fingers (ZFs) and transcriptional activator-like proteins (TALE) are amenable to bioengineering to bind DNA target sequences of interest. As a result, ZF and TALE proteins were used to develop synthetic programmable transcription factors. However, these systems are limited by the requirement to re-engineer proteins for each new target sequence. The clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR associated 9 (Cas9) genome editing tool was recently repurposed for targeted transcriptional regulation by inactivation of the nuclease activity of Cas9. Due to the facile engineering, simplicity, precision and amenability to library construction, the CRISPR/Cas9 system is poised to revolutionize the functional genomics field across diverse eukaryotic species. In this review, we discuss the development of synthetic customizable transcriptional regulators and provide insights into their current and potential applications, with special emphasis on plant systems, in characterization of gene functions, elucidation of molecular mechanisms and their biotechnological applications. © 2016 Informa UK Limited, trading as Taylor & Francis Group

  14. Role of Moringa oleifera in regulation of diabetes-induced oxidative stress

    Institute of Scientific and Technical Information of China (English)

    Dolly Jaiswal; Geeta Watal; Prashant Kumar Rai; Shikha Mehta; Sanjukta Chatterji; Surekha Shukla; Devendra Kumar Rai; Gaurav Sharma; Bechan Sharma; Shahidul khair

    2013-01-01

    Objective: To evaluate the antioxidant activity of aqueous extract of Moringa oleifera (M. oleifera) young leaves by in vivo as well as in vitro assays. Methods: In vitro study included estimation of total phenolic, total flavonol, total flavonoid and total antioxidant power (FRAP assay). In addition, in vivo study was done with the identified most effective dose of 200 mg/kg of its lyophilized powder on normal and diabetic rats. Its effect on different oxidative free radical scavenging enzymes, viz, superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), lipid peroxide (LPO) contents were measured. Results: Significant increase in activities of SOD, CAT, GST while, a decrease in LPO content was observed. Whereas, total phenolic, flavonoid and flavonol contents in the extract were found to be 120 mg/g of GAE, 40.5 mg/g of QE and 12.12 mg/g of QE, respectively. On the other hand, FRAP assay results of M. oleifera leaves was (85.00±5.00) μM of Fe++/g of extract powder. Conclusions: The significant antioxidant activities of M. oleifera leaves from both in vivo as well as in vitro studies suggests that the regular intake of its leaves through diet can protect normal as well as diabetic patients against oxidative damage.

  15. Cell swelling and volume regulation

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay

    1992-01-01

    been reported. The role of the different channels was discussed. A taurine leak pathway is clearly activated after cell swelling both in astrocytes and in neurones. The relations between the effect of glutamate and cell swelling were discussed. Discussion on the clearance of potassium from...... the extracellular space was continued. Neither the spatial buffering mechanism nor the role of the Na+/K+ pump was discussed here, but additional possibilities for K+ removal were discussed. At a high extracellular K+ concentration there is a possibility of channel-mediated KCl uptake by the glia cells, and a Na......-K-2Cl cotransport system is present in astrocytes and seems to play a role at relatively low extracellular K+ concentrations (6-20 mM). The cotransport system is likely to be regulated, but little is known about its regulation in glia cells....

  16. Information, Interests, and Environmental Regulation

    DEFF Research Database (Denmark)

    Winter, Søren; May, Peter J.

    2002-01-01

    This study contributes to the understanding of informational approaches to bringing about compliance with environmental regulations with particular attention to differences in the influence of information provided by different information sources. Based on theorizing from a combination of informa......This study contributes to the understanding of informational approaches to bringing about compliance with environmental regulations with particular attention to differences in the influence of information provided by different information sources. Based on theorizing from a combination...... of information processing and interest group literatures, we develop hypotheses about regulatees' reliance upon and the influence of different sources of information. We test these hypotheses for Danish farmers’ compliance with agro-environmental rules. Our findings show that information plays a role in bringing...

  17. Regulating health: transcending disciplinary boundaries.

    Science.gov (United States)

    Seddon, Toby

    2013-03-01

    Health and health care problems can be addressed from multiple disciplinary perspectives. This raises challenges for how to do cross-disciplinary scholarship in ways that are still robust, rigorous and coherent. This paper sets out one particular approach to cross-cutting research--regulation--which has proved extremely fertile for scholars working in diverse fields, from coal mine safety to tax compliance. The first part of the paper considers how regulatory ideas might be applied to health and health care research in general. The second part goes on to sketch out how a regulation perspective on one specific area, illicit drug policy, can open up new directions for research. In conclusion, a future research agenda is outlined for regulatory scholarship on health and health care.

  18. Epigenetic microRNA Regulation

    DEFF Research Database (Denmark)

    Wiklund, Erik Digman

    2011-01-01

    and confirming transcriptional start sites can be difficult. Epigenetics, gene regulatory and DNA modification mechanisms not involving a change to the primary sequence, have been implied in the regulation of a number of miRNA loci. Both epigenetic and miRNA signatures are broadly altered in cancer......, and are thought to play essential roles in cancer etiology and progression. Here, we aimed to identify epigenetic miRNA deregulation in bladder and oral carcinoma, and to develop a robust approach to epigenetic miRNA prediction and detection. In addition, non-canonical epigenetic functions directed by a nuclear...... miRNA were investigated. In summary, we report that the miR-200 family and miR-205 are coordinately epigenetically regulated in a variety of cell lines, tumors and normal tissues. MiR-200c expression is correlated with bladder cancer disease progression, and miR-375 levels in oral rinse can...

  19. Molecular Mechanisms of Appetite Regulation

    Directory of Open Access Journals (Sweden)

    Ji Hee Yu

    2012-12-01

    Full Text Available The prevalence of obesity has been rapidly increasing worldwide over the last several decades and has become a major health problem in developed countries. The brain, especially the hypothalamus, plays a key role in the control of food intake by sensing metabolic signals from peripheral organs and modulating feeding behaviors. To accomplish these important roles, the hypothalamus communicates with other brain areas such as the brainstem and reward-related limbic pathways. The adipocyte-derived hormone leptin and pancreatic β-cell-derived insulin inform adiposity to the hypothalamus. Gut hormones such as cholecystokinin, peptide YY, pancreatic polypeptide, glucagon-like peptide 1, and oxyntomodulin transfer satiety signals to the brain and ghrelin relays hunger signals. The endocannabinoid system and nutrients are also involved in the physiological regulation of food intake. In this article, we briefly review physiological mechanisms of appetite regulation.

  20. Designing Next Generation Telecom Regulation

    DEFF Research Database (Denmark)

    Henten, Anders; Samarajiva, Rohan

    Continuously expanding applications of information and communication technologies (ICT) are transforming local, national, regional and international economies into network economies, the foundation for information societies. They are being built upon expanded and upgraded national telecom networks......, the new information infrastructures. The point of entry to participation in these new economies and societies is through local communication networks, which determine the access possibilities and boundaries of opportunity for individuals, organisations and countries. The telecom reform process is directed...... to creating an environment to foster a massive expansion in the coverage and capabilities of the information infrastructure networks, with national telecom regulators as the key implementers of the policies of reform. The first phase of reform has focused on industry specific telecom policy and regulation...

  1. PERIPHERAL MECHANISMS IN APPETITE REGULATION

    Science.gov (United States)

    Camilleri, Michael

    2014-01-01

    Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide input to the highly organized hypothalamic circuitry and vagal complex of nuclei to determine cessation of energy intake during meal ingestion, and the return of appetite and hunger after fasting. Understanding these mechanisms is key to the physiological control of feeding and the derangements that occur in obesity and their restoration with treatment (as demonstrated by the effects of bariatric surgery). PMID:25241326

  2. Biosimilar regulation in the EU.

    Science.gov (United States)

    Kurki, Pekka; Ekman, Niklas

    2015-01-01

    In the EU, the EMA has been working with biosimilars since 1998. This experience is crystallized in the extensive set of guidelines, which range from basic principles to details of clinical trials. While the guidance may appear complicated, it has enabled the development of biosimilars, of which 21 have managed to get marketing authorization. Currently marketed biosimilars in the EU have a good track record in safety and traceability. No biosimilars have been withdrawn from the market because of safety concerns. The most controversial issues with biosimilars are immunogenicity and extrapolation of therapeutic indications. The available data for these topics do not raise concerns among EU regulators. Interchangeability and substitution are regulated by individual EU member states.

  3. Peripheral mechanisms in appetite regulation.

    Science.gov (United States)

    Camilleri, Michael

    2015-05-01

    Peripheral mechanisms in appetite regulation include the motor functions of the stomach, such as the rate of emptying and accommodation, which convey symptoms of satiation to the brain. The rich repertoire of peripherally released peptides and hormones provides feedback from the arrival of nutrients in different regions of the gut from where they are released to exert effects on satiation, or regulate metabolism through their incretin effects. Ultimately, these peripheral factors provide input to the highly organized hypothalamic circuitry and vagal complex of nuclei to determine cessation of energy intake during meal ingestion, and the return of appetite and hunger after fasting. Understanding these mechanisms is key to the physiological control of feeding and the derangements that occur in obesity and their restoration with treatment (as shown by the effects of bariatric surgery). Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

  4. Molecular mechanisms of appetite regulation.

    Science.gov (United States)

    Yu, Ji Hee; Kim, Min-Seon

    2012-12-01

    The prevalence of obesity has been rapidly increasing worldwide over the last several decades and has become a major health problem in developed countries. The brain, especially the hypothalamus, plays a key role in the control of food intake by sensing metabolic signals from peripheral organs and modulating feeding behaviors. To accomplish these important roles, the hypothalamus communicates with other brain areas such as the brainstem and reward-related limbic pathways. The adipocyte-derived hormone leptin and pancreatic β-cell-derived insulin inform adiposity to the hypothalamus. Gut hormones such as cholecystokinin, peptide YY, pancreatic polypeptide, glucagon-like peptide 1, and oxyntomodulin transfer satiety signals to the brain and ghrelin relays hunger signals. The endocannabinoid system and nutrients are also involved in the physiological regulation of food intake. In this article, we briefly review physiological mechanisms of appetite regulation.

  5. Various Themes of Myosin Regulation.

    Science.gov (United States)

    Heissler, Sarah M; Sellers, James R

    2016-05-01

    Members of the myosin superfamily are actin-based molecular motors that are indispensable for cellular homeostasis. The vast functional and structural diversity of myosins accounts for the variety and complexity of the underlying allosteric regulatory mechanisms that determine the activation or inhibition of myosin motor activity and enable precise timing and spatial aspects of myosin function at the cellular level. This review focuses on the molecular basis of posttranslational regulation of eukaryotic myosins from different classes across species by allosteric intrinsic and extrinsic effectors. First, we highlight the impact of heavy and light chain phosphorylation. Second, we outline intramolecular regulatory mechanisms such as autoinhibition and subsequent activation. Third, we discuss diverse extramolecular allosteric mechanisms ranging from actin-linked regulatory mechanisms to myosin:cargo interactions. At last, we briefly outline the allosteric regulation of myosins with synthetic compounds.

  6. Phenotyping jasmonate regulation of senescence.

    Science.gov (United States)

    Seltmann, Martin A; Berger, Susanne

    2013-01-01

    Osmotic stress induces several senescence-like processes in leaves, such as specific changes in gene expression and yellowing. These processes are dependent on the accumulation of jasmonates and on intact jasmonate signaling. This chapter describes the treatment of Arabidopsis thaliana leaves with sorbitol as an osmotic stress agent and the determination of the elicited phenotypes encompassing chlorophyll loss, degradation of plastidial membrane lipids, and induction of genes regulated by senescence and jasmonate.

  7. Regulators of Tfh cell differentiation

    Directory of Open Access Journals (Sweden)

    Gajendra Motiram Jogdand

    2016-11-01

    Full Text Available The follicular helper T (Tfh cells help is critical for activation of B cells, antibody class switching and germinal center formation. The Tfh cells are characterized by the expression of CXCR5, ICOS, PD-1, Bcl-6, and IL-21. They are involved in clearing infections and are adversely linked with autoimmune diseases and also have a role in viral replication as well as clearance. Tfh cells are generated from naïve CD4 T cells with sequential steps involving cytokine signaling (IL-21, IL-6, IL-12, activin A, migration and positioning in the germinal center by CXCR5, surface receptors (ICOS/ICOSL, SAP/SLAM as well as transcription factor (Bcl-6, c-Maf, STAT3 signaling and repressor miR155. On the other hand Tfh generation is negatively regulated at specific steps of Tfh generation by specific cytokine (IL-2, IL-7, surface receptor (PD-1, CTLA-4, transcription factors Blimp-1, STAT5, T-bet, KLF-2 signaling and repressor miR 146a. Interestingly, miR 17-92 and FOXO1 acts as a positive as well as a negative regulator of Tfh differentiation depending on the time of expression and disease specificity. Tfh cells are also generated from the conversion of other effector T cells as exemplified by Th1 cells converting into Tfh during viral infection. The mechanistic details of effector T cells conversion into Tfh are yet to be clear. To manipulate Tfh cells for therapeutic implication and or for effective vaccination strategies, it is important to know positive and negative regulators of Tfh generation. Hence, in this review we have highlighted and interlinked molecular signaling from cytokines, surface receptors, transcription factors, ubiquitin Ligase and miRNA as positive and negative regulators for Tfh differentiation.

  8. Food Regulation in Biblical Law

    OpenAIRE

    Wilkenfeld, Wendy A.

    1998-01-01

    Everyone needs to eat, yet most societies and many world religions limit the available food supply by practicing some form of dietary restriction. However, biblical law presents a special case because "few [societies] systematically define all animals as permitted or forbidden and invoke divine authority for the instructions." For at least two thousand years, people have wondered why such a complex and comprehensive system of food regulation as is found in biblical law would fail to offer any...

  9. Regulation Mechanisms of Stomatal Oscillation

    Institute of Scientific and Technical Information of China (English)

    Hui-Min YANG; Jian-Hua ZHANG; Xiao-Yan ZHANG

    2005-01-01

    Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss through transpiration. How to reduce water loss and maintain enough CO2 absorption has been an interesting research topic for some time. Simple stomatal opening may elevate CO2 absorption,but, in the meantime, promote the water loss, whereas simple closing of stomatal pores may reduce both water loss and CO2 absorption, resulting in impairment of plant photosynthesis. Both processes are not economical to the plant. As a special rhythmic stomatal movement that usually occurs at smaller stomatal apertures, stomatal oscillation can keep CO2 absorption at a sufficient level and reduce water loss at the same time, suggesting a potential improvement in water use efficiency. Stomatal oscillation is usually found after a sudden change in one environmental factor in relatively constant environments. Many environmental stimuli can induce stomatal oscillation. It appears that, at the physiological level, feedback controls are involved in stomatal oscillation. At the cellular level, possibly two different patterns exist: (i) a quicker responsive pattern; and (ii) a slower response. Both involve water potential changes and water channel regulation, but the mechanisms of regulation of the two patterns are different. Some evidence suggests that the regulation of water channels may play a vital and primary role in stomatal oscillation. The present review summarizes studies on stomatal oscillation and concludes with some discussion regarding the mechanisms of regulation of stomatal oscillation.

  10. The mother as hidden regulator

    Directory of Open Access Journals (Sweden)

    Annie Panzer

    2003-09-01

    Full Text Available A human baby is born with a decidedly immature brain, and is absolutely dependent on an intense relationship with its mother (or primary caregiver for brain maturation. In the short term, maternal regulation contributes to a more joyful baby, while in the long term it leads to the internalisation and development of self-regulatory capabilities. The ability to regulate one’s own emotional states is based on the development of right orbitofrontal dominance of dual limbic circuits, i.e. the excitatory sympathetic ventral tegmental circuit, and the inhibitory parasympathetic lateral tegmental circuit. Thus the child will be able to calm down after nigh overwhelming emotions by activating the parasympathetic system, but also to bounce back after setbacks by activating the sympathetic system. The mother influences the parcellation of the two limbic systems and thus the permanent excitation-inhibition autonomic balance of its prefrontal regulatory system. Repeated unregulated emotional states in the practicing period from 12-18 months pave the way for various psychological and psychiatric disorders in adulthood. It is worrisome that many children pass through this critical time in nursery schools, where a shortage of adult staff may lead to the scenario where a child’s emotions are repeatedly not modulated, with dire consequences for the internalisation of its future self-regulating capabilities.

  11. Epigenetic regulation of protein glycosylation.

    Science.gov (United States)

    Zoldoš, Vlatka; Grgurević, Srđana; Lauc, Gordan

    2010-10-01

    Protein N-glycosylation is an ancient metabolic pathway that still exists in all three domains of life (Archaea, Bacteria and Eukarya). The covalent addition of one or more complex oligosaccharides (glycans) to protein backbones greatly diversifies their structures and makes the glycoproteome several orders of magnitude more complex than the proteome itself. Contrary to polypeptides, which are defined by a sequence of nucleotides in the corresponding genes, the glycan part of glycoproteins are encoded in a complex dynamic network of hundreds of proteins, whereby activity is defined by both genetic sequence and the regulation of gene expression. Owing to the complex nature of their biosynthesis, glycans are particularly versatile and apparently a large part of human variation derives from differences in protein glycosylation. Composition of the individual glycome appears to be rather stable, and thus differences in the pattern of glycan synthesis between individuals could originate either from genetic polymorphisms or from stable epigenetic regulation of gene expression in different individuals. Studies of epigenetic modification of genes involved in protein glycosylation are still scarce, but their results indicate that this process might be very important for the regulation of protein glycosylation.

  12. Epigenetic regulation in Parkinson's disease.

    Science.gov (United States)

    Labbé, Catherine; Lorenzo-Betancor, Oswaldo; Ross, Owen A

    2016-10-01

    Recent efforts have shed new light on the epigenetic mechanisms driving gene expression alterations associated with Parkinson's disease (PD) pathogenesis. Changes in gene expression are a well-established cause of PD, and epigenetic mechanisms likely play a pivotal role in regulation. Studies in families with PD harboring duplications and triplications of the SNCA gene have demonstrated that gene dosage is associated with increased expression of both SNCA mRNA and protein, and correlates with a fulminant disease course. Furthermore, it is postulated that even subtle changes in SNCA expression caused by common variation is associated with disease risk. Of note, genome-wide association studies have identified over 30 loci associated with PD with most signals located in non-coding regions of the genome, thus likely influencing transcript expression levels. In health, epigenetic mechanisms tightly regulate gene expression, turning genes on and off to balance homeostasis and this, in part, explains why two cells with the same DNA sequence will have different RNA expression profiles. Understanding this phenomenon will be crucial to our interpretation of the selective vulnerability observed in neurodegeneration and specifically dopaminergic neurons in the PD brain. In this review, we discuss epigenetic mechanisms, such as DNA methylation and histone modifications, involved in regulating the expression of genes relevant to PD, RNA-based mechanisms, as well as the effect of toxins and potential epigenetic-based treatments for PD.

  13. Mechanosensitive mechanisms in transcriptional regulation.

    Science.gov (United States)

    Mammoto, Akiko; Mammoto, Tadanori; Ingber, Donald E

    2012-07-01

    Transcriptional regulation contributes to the maintenance of pluripotency, self-renewal and differentiation in embryonic cells and in stem cells. Therefore, control of gene expression at the level of transcription is crucial for embryonic development, as well as for organogenesis, functional adaptation, and regeneration in adult tissues and organs. In the past, most work has focused on how transcriptional regulation results from the complex interplay between chemical cues, adhesion signals, transcription factors and their co-regulators during development. However, chemical signaling alone is not sufficient to explain how three-dimensional (3D) tissues and organs are constructed and maintained through the spatiotemporal control of transcriptional activities. Accumulated evidence indicates that mechanical cues, which include physical forces (e.g. tension, compression or shear stress), alterations in extracellular matrix (ECM) mechanics and changes in cell shape, are transmitted to the nucleus directly or indirectly to orchestrate transcriptional activities that are crucial for embryogenesis and organogenesis. In this Commentary, we review how the mechanical control of gene transcription contributes to the maintenance of pluripotency, determination of cell fate, pattern formation and organogenesis, as well as how it is involved in the control of cell and tissue function throughout embryogenesis and adult life. A deeper understanding of these mechanosensitive transcriptional control mechanisms should lead to new approaches to tissue engineering and regenerative medicine.

  14. Epigenetic microRNA Regulation

    DEFF Research Database (Denmark)

    Wiklund, Erik Digman

    2011-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs (ncRNAs) that negatively regulate gene expression post-transcriptionally by binding to complementary sequences in the 3’UTR of target mRNAs in the cytoplasm. However, recent evidence suggests that certain miRNAs are enriched in the nucleus......, and their targets do not seem restricted to mRNA 3’UTRs. Therefore, miRNAs are predicted to have a variety functions throughout mammalian cells. MiRNA genes appear to be regulated in much the same way as coding genes, but current insight into transcriptional miRNA control lacks detail, as mapping miRNA promoters...... and confirming transcriptional start sites can be difficult. Epigenetics, gene regulatory and DNA modification mechanisms not involving a change to the primary sequence, have been implied in the regulation of a number of miRNA loci. Both epigenetic and miRNA signatures are broadly altered in cancer...

  15. Hate crimes and normative regulation

    Directory of Open Access Journals (Sweden)

    Kovačević Milica

    2011-01-01

    Full Text Available This paper is primarily devoted to issues related to the normative regulation of hate crimes, with special reference to the regulations of the Republic of Serbia, which are indirectly related to this matter. This kind of crimes are characterized by prejudices that perpetrators have towards injured parties, as members of certain, mostly, minority groups, due to which many hate crimes could be also called crimes of prejudice. In comparative law there are two different basic directions when it comes to regulating hate crimes: separation of hate crimes in a separate category on the one hand, and punishment of perpetrators of criminal acts with the detriment of minority groups through the usual charges of a given criminal justice system, on the other. The author finds that, regardless of the formal response forms, real life suggests that hate crimes can be essentially suppressed only by promoting values such as equality, respect for diversity and tolerance, and by continuous education of public about the danger of hate crimes.

  16. Regulation of Rad51 promoter

    Science.gov (United States)

    Hine, Christopher M; Li, Hongjie; Xie, Li; Mao, Zhiyong; Seluanov, Andrei; Gorbunova, Vera

    2014-01-01

    The DNA double-strand break repair and homologous recombination protein Rad51 is overexpressed in the majority of human cancers. This correlates with therapy resistance and decreased patient survival. We previously showed that constructs containing Rad51 promoter fused to a reporter gene are, on average, 850-fold more active in cancer cells than in normal cells. It is not well understood what factors and sequences regulate the Rad51 promoter and cause its high activity in cancerous cells. Here we characterized regulatory regions and examined genetic requirements for oncogenic stimulation of the Rad51 promoter. We identified specific regions responsible for up- and downregulation of the Rad51 promoter in cancerous cells. Furthermore, we show that Rad51 expression is positively regulated by EGR1 transcription factor. We then modeled the malignant transformation process by expressing a set of oncoproteins in normal human fibroblasts. Expression of different combinations of SV40 large T antigen, oncogenic Ras and SV40 small T antigen resulted in step-wise increase in Rad51 promoter activity, with all the 3 oncoproteins together leading to a 47-fold increase in expression. Cumulatively, these results suggest that Rad51 promoter is regulated by multiple factors, and that its expression is gradually activated as cells progress toward malignancy. PMID:24781030

  17. Substrate curvature regulates cell migration

    Science.gov (United States)

    He, Xiuxiu; Jiang, Yi

    2017-06-01

    Cell migration is essential in many aspects of biology. Many basic migration processes, including adhesion, membrane protrusion and tension, cytoskeletal polymerization, and contraction, have to act in concert to regulate cell migration. At the same time, substrate topography modulates these processes. In this work, we study how substrate curvature at micrometer scale regulates cell motility. We have developed a 3D mechanical model of single cell migration and simulated migration on curved substrates with different curvatures. The simulation results show that cell migration is more persistent on concave surfaces than on convex surfaces. We have further calculated analytically the cell shape and protrusion force for cells on curved substrates. We have shown that while cells spread out more on convex surfaces than on concave ones, the protrusion force magnitude in the direction of migration is larger on concave surfaces than on convex ones. These results offer a novel biomechanical explanation to substrate curvature regulation of cell migration: geometric constrains bias the direction of the protrusion force and facilitates persistent migration on concave surfaces.

  18. Steroid hormones and sleep regulation.

    Science.gov (United States)

    Terán-Pérez, G; Arana-Lechuga, Y; Esqueda-León, E; Santana-Miranda, R; Rojas-Zamorano, J Á; Velázquez Moctezuma, J

    2012-10-01

    In the search of the sleep substance, many studies have been addressed for different hormones, responsible for sleep-wake cycle regulation. In this article we mentioned the participation of steroid hormones, besides its role regulating sexual behavior, they influence importantly in the sleep process. One of the clearest relationships are that estrogen and progesterone have, that causing changes in sleep patterns associated with the hormonal cycles of women throughout life, from puberty to menopause and specific periods such as pregnancy and the menstrual cycle, including being responsible for some sleep disorders such as hypersomnia and insomnia. Another studied hormone is cortisol, a hormone released in stressful situations, when an individual must react to an extraordinary demand that threatens their survival, but also known as the hormone of awakening because the release peak occurs in the morning, although this may be altered in some sleep disorders like insomnia and mood disorders. Furthermore neurosteroids such as pregnanolone, allopregnanolone and pregnenolone are involved in the generation of slow wave sleep, the effect has been demonstrated in experimental animal studies. Thus we see that the sleep and the endocrine system saved a bidirectional relationship in which depends on each other to regulate different physiological processes including sleep.

  19. NRC - regulator of nuclear safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The U.S. Nuclear Regulatory Commission (NRC) was formed in 1975 to regulate the various commercial and institutional uses of nuclear energy, including nuclear power plants. The agency succeeded the Atomic Energy Commission, which previously had responsibility for both developing and regulating nuclear activities. Federal research and development work for all energy sources, as well as nuclear weapons production, is now conducted by the U.S. Department of Energy. Under its responsibility to protect public health and safety, the NRC has three principal regulatory functions: (1) establish standards and regulations, (2) issue licenses for nuclear facilities and users of nuclear materials, and (3) inspect facilities and users of nuclear materials to ensure compliance with the requirements. These regulatory functions relate to both nuclear power plants and to other uses of nuclear materials - like nuclear medicine programs at hospitals, academic activities at educational institutions, research work, and such industrial applications as gauges and testing equipment. The NRC places a high priority on keeping the public informed of its work. The agency recognizes the interest of citizens in what it does through such activities as maintaining public document rooms across the country and holding public hearings, public meetings in local areas, and discussions with individuals and organizations.

  20. Musical affect regulation in infancy.

    Science.gov (United States)

    Trehub, Sandra E; Ghazban, Niusha; Corbeil, Mariève

    2015-03-01

    Adolescents and adults commonly use music for various forms of affect regulation, including relaxation, revitalization, distraction, and elicitation of pleasant memories. Mothers throughout the world also sing to their infants, with affect regulation as the principal goal. To date, the study of maternal singing has focused largely on its acoustic features and its consequences for infant attention. We describe recent laboratory research that explores the consequences of singing for infant affect regulation. Such work reveals that listening to recordings of play songs can maintain 6- to 9-month-old infants in a relatively contented or neutral state considerably longer than recordings of infant-directed or adult-directed speech. When 10-month-old infants fuss or cry and are highly aroused, mothers' multimodal singing is more effective than maternal speech at inducing recovery from such distress. Moreover, play songs are more effective than lullabies at reducing arousal in Western infants. We explore the implications of these findings along with possible practical applications.

  1. RegulatING chromatin regulators: post-translational modification of the ING family of epigenetic regulators.

    Science.gov (United States)

    Satpathy, Shankha; Nabbi, Arash; Riabowol, Karl

    2013-03-15

    The five human ING genes encode at least 15 splicing isoforms, most of which affect cell growth, differentiation and apoptosis through their ability to alter gene expression by epigenetic mechanisms. Since their discovery in 1996, ING proteins have been classified as type II tumour suppressors on the basis of reports describing their down-regulation and mislocalization in a variety of cancer types. In addition to their regulation by transcriptional mechanisms, understanding the range of PTMs (post-translational modifications) of INGs is important in understanding how ING functions are fine-tuned in the physiological setting and how they add to the repertoire of activities affected by the INGs. In the present paper we review the different PTMs that have been reported to occur on INGs. We discuss the PTMs that modulate ING function under normal conditions and in response to a variety of stresses. We also describe the ING PTMs that have been identified by several unbiased MS-based PTM enrichment techniques and subsequent proteomic analysis. Among the ING PTMs identified to date, a subset has been characterized for their biological significance and have been shown to affect processes including subcellular localization, interaction with enzymatic complexes and ING protein half-life. The present review aims to highlight the emerging role of PTMs in regulating ING function and to suggest additional pathways and functions where PTMs may effect ING function.

  2. Tewaukon National Wildlife Refuge: Summer Fishing Regulation

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This memorandum summarizes the summer fishing regulation for Tewaukon National Wildlife Refuge as submitted to the Federal Register. This regulation defines areas...

  3. Self-tuning regulators. [adaptive control research

    Science.gov (United States)

    Astrom, K. J.

    1975-01-01

    The results of a research project are discussed for self-tuning regulators for active control. An algorithm for the self-tuning regulator is described as being stochastic, nonlinear, time variable, and not trivial.

  4. Working without limits – reconsidering regulation

    DEFF Research Database (Denmark)

    Jensen, Per Langå

    2001-01-01

    In the light ofthe development of industry and working conditions present challenges to regulation is presented.......In the light ofthe development of industry and working conditions present challenges to regulation is presented....

  5. Cholinergic regulation of airway inflammation and remodelling

    NARCIS (Netherlands)

    Kolahian, Saeed; Gosens, Reinoud

    2012-01-01

    Acetylcholine is the predominant parasympathetic neurotransmitter in the airways that regulates bronchoconstriction and mucus secretion. Recent findings suggest that acetylcholine regulates additional functions in the airways, including inflammation and remodelling during inflammatory airway disease

  6. Feedback regulation between autophagy and PKA

    Science.gov (United States)

    Torres-Quiroz, Francisco; Filteau, Marie; Landry, Christian R

    2015-01-01

    Protein kinase A (PKA) controls diverse cellular processes and homeostasis in eukaryotic cells. Many processes and substrates of PKA have been described and among them are direct regulators of autophagy. The mechanisms of PKA regulation and how they relate to autophagy remain to be fully understood. We constructed a reporter of PKA activity in yeast to identify genes affecting PKA regulation. The assay systematically measures relative protein-protein interactions between the regulatory and catalytic subunits of the PKA complex in a systematic set of genetic backgrounds. The candidate PKA regulators we identified span multiple processes and molecular functions (autophagy, methionine biosynthesis, TORC signaling, protein acetylation, and DNA repair), which themselves include processes regulated by PKA. These observations suggest the presence of many feedback loops acting through this key regulator. Many of the candidate regulators include genes involved in autophagy, suggesting that not only does PKA regulate autophagy but that autophagy also sends signals back to PKA. PMID:26046386

  7. Back Bay National Wildlife Refuge regulations

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This document is a collection of regulations pertaining to the Back Bay National Wildlife Refuge. Most of the regulations concern motor vehicle use on the refuge.

  8. Feedback regulation between autophagy and PKA.

    Science.gov (United States)

    Torres-Quiroz, Francisco; Filteau, Marie; Landry, Christian R

    2015-01-01

    Protein kinase A (PKA) controls diverse cellular processes and homeostasis in eukaryotic cells. Many processes and substrates of PKA have been described and among them are direct regulators of autophagy. The mechanisms of PKA regulation and how they relate to autophagy remain to be fully understood. We constructed a reporter of PKA activity in yeast to identify genes affecting PKA regulation. The assay systematically measures relative protein-protein interactions between the regulatory and catalytic subunits of the PKA complex in a systematic set of genetic backgrounds. The candidate PKA regulators we identified span multiple processes and molecular functions (autophagy, methionine biosynthesis, TORC signaling, protein acetylation, and DNA repair), which themselves include processes regulated by PKA. These observations suggest the presence of many feedback loops acting through this key regulator. Many of the candidate regulators include genes involved in autophagy, suggesting that not only does PKA regulate autophagy but that autophagy also sends signals back to PKA.

  9. Regulation of amniotic fluid volume.

    Science.gov (United States)

    Beall, M H; van den Wijngaard, J P H M; van Gemert, M J C; Ross, M G

    2007-01-01

    Water arrives in the mammalian gestation from the maternal circulation across the placenta. It then circulates between the fetal water compartments, including the fetal body compartments, the placenta and the amniotic fluid. Amniotic fluid is created by the flow of fluid from the fetal lung and bladder. A major pathway for amniotic fluid resorption is fetal swallowing; however, in many cases the amounts of fluid produced and absorbed do not balance. A second resorption pathway, the intramembranous pathway (across the amnion to the fetal circulation), has been proposed to explain the maintenance of normal amniotic fluid volume. Amniotic fluid volume is thus a function both of the amount of water transferred to the gestation across the placental membrane, and the flux of water across the amnion. Water flux across biologic membranes may be driven by osmotic or hydrostatic forces; existing data suggest that intramembranous flow in humans is driven by the osmotic difference between the amniotic fluid and the fetal serum. The driving force for placental flow is more controversial, and both forces may be in effect. The mechanism(s) responsible for regulating water flow to and from the amniotic fluid is unknown. In other parts of the body, notably the kidney, water flux is regulated by the expression of aquaporin water channels on the cell membrane. We hypothesize that aquaporins have a role in regulating water flux across both the amnion and the placenta, and present evidence in support of this theory. Current knowledge of gestational water flow is sufficient to allow prediction of fetal outcome when water flow is abnormal, as in twin-twin transfusion syndrome. Further insight into these mechanisms may allow novel treatments for amniotic fluid volume abnormalities with resultant improvement in clinical outcome.

  10. Securities regulation and implicit penalties

    Institute of Scientific and Technical Information of China (English)

    Donghua; Chen; Yuyan; Guan; Gang; Zhao; Feifei; Wu

    2011-01-01

    The extant literature offers extensive support for the significant role played by institutions in financial markets,but implicit regulation and monitoring have yet to be examined.This study fills this void in the literature by employing unique Chinese datasets to explore the implicit regulation and penalties imposed by the Chinese government in regulating the initial public offering(IPO) market.Of particular interest are the economic consequences of underwriting IPO deals for client firms that violate regulatory rules in China’s capital market.We provide evidence to show that the associated underwriters’ reputations are impaired and their market share declines.We further explore whether such negative consequences result from a market disciplinary mechanism or a penalty imposed by the government.To analyze the possibility of a market disciplinary mechanism at work,we investigate(1) the market reaction to other client firms whose IPO deals were underwritten by underwriters associated with a violation at the time the violation was publicly disclosed and(2) the under-pricing of IPO deals undertaken by these underwriters after such disclosure.To analyze whether the government imposes an implicit penalty,we examine the application processing time for future IPO deals underwritten by the associated underwriters and find it to be significantly longer than for IPO deals underwritten by other underwriters.Overall,there is little evidence to suggest that the market penalizes underwriters for the rule-violating behavior of their client firms in China.Instead,the Chinese government implicitly penalizes them by imposing more stringent criteria on and lengthening the processing time of the IPO deals they subsequently underwrite.

  11. Securities regulation and implicit penalties

    Directory of Open Access Journals (Sweden)

    Donghua Chen

    2011-06-01

    Full Text Available The extant literature offers extensive support for the significant role played by institutions in financial markets, but implicit regulation and monitoring have yet to be examined. This study fills this void in the literature by employing unique Chinese datasets to explore the implicit regulation and penalties imposed by the Chinese government in regulating the initial public offering (IPO market. Of particular interest are the economic consequences of underwriting IPO deals for client firms that violate regulatory rules in China’s capital market. We provide evidence to show that the associated underwriters’ reputations are impaired and their market share declines. We further explore whether such negative consequences result from a market disciplinary mechanism or a penalty imposed by the government. To analyze the possibility of a market disciplinary mechanism at work, we investigate (1 the market reaction to other client firms whose IPO deals were underwritten by underwriters associated with a violation at the time the violation was publicly disclosed and (2 the under-pricing of IPO deals undertaken by these underwriters after such disclosure. To analyze whether the government imposes an implicit penalty, we examine the application processing time for future IPO deals underwritten by the associated underwriters and find it to be significantly longer than for IPO deals underwritten by other underwriters. Overall, there is little evidence to suggest that the market penalizes underwriters for the rule-violating behavior of their client firms in China. Instead, the Chinese government implicitly penalizes them by imposing more stringent criteria on and lengthening the processing time of the IPO deals they subsequently underwrite.

  12. Regulated polyploidy in halophilic archaea.

    Directory of Open Access Journals (Sweden)

    Sebastian Breuert

    Full Text Available Polyploidy is common in higher eukaryotes, especially in plants, but it is generally assumed that most prokaryotes contain a single copy of a circular chromosome and are therefore monoploid. We have used two independent methods to determine the genome copy number in halophilic archaea, 1 cell lysis in agarose blocks and Southern blot analysis, and 2 Real-Time quantitative PCR. Fast growing H. salinarum cells contain on average about 25 copies of the chromosome in exponential phase, and their ploidy is downregulated to 15 copies in early stationary phase. The chromosome copy number is identical in cultures with a twofold lower growth rate, in contrast to the results reported for several other prokaryotic species. Of three additional replicons of H. salinarum, two have a low copy number that is not growth-phase regulated, while one replicon even shows a higher degree of growth phase-dependent regulation than the main replicon. The genome copy number of H. volcanii is similarly high during exponential phase (on average 18 copies/cell, and it is also downregulated (to 10 copies as the cells enter stationary phase. The variation of genome copy numbers in the population was addressed by fluorescence microscopy and by FACS analysis. These methods allowed us to verify the growth phase-dependent regulation of ploidy in H. salinarum, and they revealed that there is a wide variation in genome copy numbers in individual cells that is much larger in exponential than in stationary phase. Our results indicate that polyploidy might be more widespread in archaea (or even prokaryotes in general than previously assumed. Moreover, the presence of so many genome copies in a prokaryote raises questions about the evolutionary significance of this strategy.

  13. VLSI Hybrid DC-DC Regulator

    OpenAIRE

    Cosp Vilella, Jordi; Martínez García, Herminio

    2015-01-01

    Hybrid DC-DC regulators are structures that combine both a linear voltage regulator and a switching DC-DC converter. The main objective of this hybrid topology is to converge, in a single circuit topology, the best of both alternatives: a small voltage output ripple, which is a common characteristic of linear regulator circuits, and good energy efficiency, as in switching alternatives. While the linear regulator fixes the required output voltage to a fixed value with negligible steady-state r...

  14. Output Regulation of the Arneodo Chaotic System

    OpenAIRE

    Sundarapandian Vaidyanathan

    2010-01-01

    This paper solves the problem of regulating the output of the Arneodo chaotic system (1981), which is one of the paradigms of chaotic dynamical systems. Explicitly, using the state feedback control laws, the output of the Arneodo chaotic system is regulated so as to track constant reference signals as well as to track periodic reference signals. The control laws are derived using the regulator equations of Byrnes and Isidori (1990), which provide the solution of the output regulation problem ...

  15. Should Financial Sector Regulators Be Independent?

    OpenAIRE

    Marc G Quintyn; Taylor, Michael W.

    2004-01-01

    In nearly every major financial crisis of the past decade-from East Asia to Russia, Turkey, and Latin America-political interference in financial sector regulation helped make a bad situation worse. Political pressures not only weakened financial regulation, but also hindered regulators and supervisors from taking action against troubled banks. This paper investigates why, to fulfill their mandate to preserve financial sector stability, financial sector regulators and supervisors need to be i...

  16. MicroRNA Regulation of SIRT1

    OpenAIRE

    Yamakuchi, Munekazu

    2012-01-01

    SIRT1 is an NAD-dependent deacetylase that regulates stress response pathways. By deacetylating transcription factors and co-factors, SIRT1 modulates metabolism, inflammation, hypoxic responses, circadian rhythms, cell survival, and longevity. Since SIRT1 plays a key role in regulating pathways involved in cardiovascular diseases and metabolic diseases cancer, the regulation of SIRT1 has received intense scrutiny. The post-transcriptional regulation of SIRT1 is mediated by two classes of mole...

  17. MicroRNA Regulation of SIRT1

    OpenAIRE

    Yamakuchi, Munekazu

    2012-01-01

    SIRT1 is an NAD-dependent deacetylase that regulates stress response pathways. By deacetylating transcription factors and co-factors, SIRT1 modulates metabolism, inflammation, hypoxic responses, circadian rhythms, cell survival, and longevity. Since SIRT1 plays a key role in regulating pathways involved in cardiovascular diseases and metabolic diseases cancer, the regulation of SIRT1 has received intense scrutiny. The post-transcriptional regulation of SIRT1 is mediated by two classes of mole...

  18. Autonomic Regulation of Splanchnic Circulation

    Directory of Open Access Journals (Sweden)

    Kathleen A Fraser

    1991-01-01

    Full Text Available The role of the autonomic nervous system in circulatory regulation of the splanchnic organs (stomach, small intestine, colon, liver, pancreas and spleen is reviewed. In general, the sympathetic nervous system is primarily involved in vasoconstriction, while the parasympathetic contributes to vasodilation. Vasoconstriction in the splanchnic circulation appears to be mediated by alpha-2 receptors and vasodilation by activation of primary afferent nerves with subsequent release of vasodilatory peptides, or by stimulation of beta-adrenergic receptors. As well, an important function of the autonomic nervous system is to provide a mechanism by which splanchnic vascular reserve can be mobilized during stress to maintain overall cardiovascular homeostasis.

  19. Content delivery network and regulation

    Institute of Scientific and Technical Information of China (English)

    PENG Jiu-sheng; LIANG Xiong-jian

    2006-01-01

    First, this article provides an introduction to the content delivery network (CDN), which has wide prospects but is still in its early stages in China. Second, this article depicts the present situation and the developing characteristics of CDN in China. Elaborating on the above-mentioned two points, this article identifies the numerous problems that are encountered during the development of CDN, such as indistinct service positioning and the hidden troubles of information security.Finally, this article presents several countermeasures for handling the problems, such as opening the market widely,making a rational service positioning, strengthening the regulation on information security, and punishing illegal operations and unfair competition.

  20. Environmental justice regulations draw fire

    Science.gov (United States)

    Showstack, Randy

    Advocates of "environmental justice" say that proposed U.S. Environmental Protection Agency (EPA) regulations are necessary to ensure that an unfair share of industrial facilities and waste plants are not sited in poor and minority communities, as they claim has occurred in the past.However, a number of state and local government agencies, business groups, and Democratic and Republican politicians argue that EPA guidelines—written to put some teeth into the Title VI clause of the Civil Rights Act that prohibits discrimination in all federally funded programs and activities—are unworkable and need to be overhauled.

  1. Regulation possibilities of biomass combustion

    Science.gov (United States)

    Suzdalenko, Vera; Gedrovics, Martins; Zake, Maija; Barmina, Inesa

    2012-11-01

    The focus of the recent experimental research is to analyze the regulation possibilities of biomass combustion. Three possibilities were chosen as part of this research: a) biomass cofiring with propane, b) swirling flow with re-circulation zone, and c) use of a permanent magnet. The aim of the research is to provide stable, controllable and effective biomass combustion with minimum emissions. The special pilot device was created where biomass can be combusted separately and co-fired with propane. Wood pellets were used during the experiments.

  2. Regulating renewable resources under uncertainty

    DEFF Research Database (Denmark)

    Hansen, Lars Gårn

    Renewable natural resources (like water, fish and wildlife stocks, forests and grazing lands) are critical for the livelihood of millions of people and understanding how they can be managed efficiently is an important economic problem. I show how regulator uncertainty about different economic......) that a pro-quota result under uncertainty about prices and marginal costs is unlikely, requiring that the resource growth function is highly concave locally around the optimum and, 3) that quotas are always preferred if uncertainly about underlying structural economic parameters dominates. These results...

  3. Neurobiology of Circadian Rhythm Regulation.

    Science.gov (United States)

    Rosenwasser, Alan M; Turek, Fred W

    2015-12-01

    Over the past few decades, multilevel research has elucidated the basic neuroanatomy, neurochemistry, and molecular neurobiology of the master circadian pacemaker located in the hypothalamic suprachiasmatic nucleus (SCN). The circadian timing system is composed of a large number of cellular oscillators located in the SCN, in non-SCN brain structures, and throughout the body. Cellular-level oscillations are generated by a molecular feedback loop in which circadian clock genes rhythmically regulate their own transcription, as well as that of hundreds of clock-controlled genes. The maintenance of proper coordination within this network of cellular- and tissue-level clocks is essential for health and well-being.

  4. The Cost of Railroad Regulation

    DEFF Research Database (Denmark)

    Federico, Giovanni; Sharp, Paul R.

    We investigate the costs of transportation regulation using the example of agricultural markets in the United States. Using a large database of prices by state of agricultural commodities, we find that the coefficient of variation (as a measure of market integration between states) falls for many...... commodities until the First World War. We demonstrate that this reflected changes in transportation costs which in turn in the long run depended on productivity growth in railroads. 1920 marked a change in this relationship, however, and between the First and Second World Wars we find considerable...

  5. Hard work in soft regulation

    DEFF Research Database (Denmark)

    Hohnen, Pernille; Hasle, Peter; Helbo Jespersen, Anne

    2014-01-01

    Certified occupational health and safety management (OHSM) systems have become a global instrument in the regulation of work environment (Frick and Wren 2000; Gallagher et al. 2001, Rocha 2010; Robson et al 2007). However, their actual impact on occupational health and safety – in particular on ‘...... issues are related to general social regulatory mechanisms in international standards....... specifically on psychosocial risk management attempting to guide and control not only management systems and related procedures but also the concrete work domain in which psychosocial risks are produced, experienced and monitored (Leka 2011). Based on an analysis of OHSAS 18001 and PAS 1010 the present paper...

  6. Power electronics converters and regulators

    CERN Document Server

    Dokić, Branko L

    2015-01-01

    This book is the result of the extensive experience the authors gained through their year-long occupation at the Faculty of Electrical Engineering at the University of Banja Luka. Starting at the fundamental basics of electrical engineering, the book guides the reader into this field and covers all the relevant types of converters and regulators. Understanding is enhanced by the given examples, exercises and solutions. Thus this book can be used as a textbook for students, for self-study or as a reference book for professionals.

  7. QB1 - Stochastic Gene Regulation

    Energy Technology Data Exchange (ETDEWEB)

    Munsky, Brian [Los Alamos National Laboratory

    2012-07-23

    Summaries of this presentation are: (1) Stochastic fluctuations or 'noise' is present in the cell - Random motion and competition between reactants, Low copy, quantization of reactants, Upstream processes; (2) Fluctuations may be very important - Cell-to-cell variability, Cell fate decisions (switches), Signal amplification or damping, stochastic resonances; and (3) Some tools are available to mode these - Kinetic Monte Carlo simulations (SSA and variants), Moment approximation methods, Finite State Projection. We will see how modeling these reactions can tell us more about the underlying processes of gene regulation.

  8. Turbinski regulator za male hidroelektrarne

    OpenAIRE

    Bergoč, Primož

    2015-01-01

    V pričujočem delu je predstavljen razvoj turbinskega regulatorja za male hidroelektrarne s sinhronskim generatorjem. Turbinski regulator je pomemben člen vsakega hidro agregata, saj je njegova naloga vzdrževati turbino v želeni delovni točki glede na izbran režim obratovanja z reguliranjem odprtja izvršnih členov. Izvršni členi so lahko vodilnik, gonilnik ali iglasti ventil in odrezač, odvisno od vrste turbine. Algoritem turbinskega regulatorja smo izvedli na programirljivem logičnem krmi...

  9. Regulating renewable resources under uncertainty

    DEFF Research Database (Denmark)

    Hansen, Lars Gårn

    Renewable natural resources (like water, fish and wildlife stocks, forests and grazing lands) are critical for the livelihood of millions of people and understanding how they can be managed efficiently is an important economic problem. I show how regulator uncertainty about different economic......) that a pro-quota result under uncertainty about prices and marginal costs is unlikely, requiring that the resource growth function is highly concave locally around the optimum and, 3) that quotas are always preferred if uncertainly about underlying structural economic parameters dominates. These results...

  10. Menstrual regulation with prostaglandin analogues.

    Science.gov (United States)

    Hagenfeldt, K; Bygdeman, M

    1981-01-01

    The development of generally applicable, simple non-surgical methods for menstrual regulation has been desired for a long time. Such an approach to fertility control depends on the availability of a suitable therapeutic agent that should be effective, reliable, simple to administer and free from disturbing side effects. The classical prostaglandins have shown the capability but are unsuitable mainly due to high incidence of side effects. Most of these drawbacks seem to be overcome when prostaglandin analogues are used; however, vaginal administration caused appreciable pain in 10-30% of women, and so severely limits self-administration of these analogues.

  11. Hard work in soft regulation

    DEFF Research Database (Denmark)

    Hohnen, Pernille; Hasle, Peter; Helbo Jespersen, Anne

    Certified occupational health and safety management (OHSM) systems have become a global instrument in the regulation of work environment. However, their actual impact on occupational health and safety – in particular on ‘softer’ psychosocial areas of the working environment – has been questioned....... This has resulted in recent British attempts to develop publically available guidelines (PAS 1010) to be used together with OHSAS 18001 focusing specifically on psychosocial risk management. The paper discusses these attempts in light of recent sociological theories on the regulatory mechanisms...

  12. Returning common sense to regulations

    Energy Technology Data Exchange (ETDEWEB)

    Fox, M.R.

    1995-10-01

    While these sessions of the November 1995 meeting of the American Nuclear Society are being devoted to the Linear Theory of harm from radiation, it must be realized that the low-level radiation issue, as important as it may be, is but a subset of an entire body of environmental issues running afoul of common sense. Cellular phones, electromagnetic fields, asbestos, dioxin, acid rain, and others especially in their public portrayals, some in their regulatory treatment, are based upon exaggerated or misunderstood risks. One must recognize that what lies ahead is an immense effort to revisit the underlying science of the existing regulations of radiation exposures. New evidence has been published, and most importantly, it is now recognized that many of these regulations--promulgated with the best of intentions--have been extraordinarily harmful to the public. In many cases, the harm has been exaggerated, and has created in the public policy arena the notion that the public is at great risk from the smallest sources of radiation. The national cost of compliance with these regulations has been enormous. To the extent that existing environmental regulations are not being moderated, they pose major economic threats to present and future industries involving nuclear materials and technology. These would include the pharmaceutical industries as well as those seeking U.S. isotope markets in separations, purification, labeling, and manufacturing of new radiopharmaceuticals for cancer therapy, diagnosis, pain mitigation, treatment of arthritis, and other new applications. For those who are not aware of the results of recent advances in radiopharmaceuticals, clinical trials have demonstrated an 80% remission rate in the treatment of b-cell lymphoma and leukemia. New isotopes and new isotope technology promise greater effectiveness in the treatment of cancer and other diseases. The regulatory problems and their enormous costs exist at all stages in nuclear medicine, from the

  13. Explaining (Missing) Regulator Paradigm Shifts

    DEFF Research Database (Denmark)

    Wigger, Angela; Buch-Hansen, Hubert

    2014-01-01

    of competition regulation is heaving into sight. It sets out to explain this from the vantage point of a critical political economy perspective, which identifies the circumstances under which a crisis can result in a regulatory paradigm shift. Contrasting the current situation with the shift in EC/EU competition...... capitalism; the social power configuration underpinning the neoliberal order remains unaltered; no clear counter-project has surfaced; the European Commission has been (and remains) in a position to oppose radical changes; and finally, there are no signs of a wider paradigm shift in the EU's regulatory...

  14. Emotion Regulation and Depressive Symptoms in Preadolescence

    Science.gov (United States)

    Siener, Shannon; Kerns, Kathryn A.

    2012-01-01

    This study examined associations among several measures of emotion regulation, and their links to depressive symptoms, in a sample of children ages 10-12 years old (N = 87). Both temporal features of emotion regulation and regulation processes involved in the evaluation, monitoring, and modification of emotion were assessed through parent and…

  15. Multiplexing regulated traffic streams: design and performance

    NARCIS (Netherlands)

    Kumaran, Krishnan; Mandjes, Michel

    2001-01-01

    The main network solutions for supporting QoS rely on traf- fic policing (conditioning, shaping). In particular, for IP networks the IETF has developed Intserv (individual flows regulated) and Diffserv (only ag- gregates regulated). The regulator proposed could be based on the (dual) leaky-bucket me

  16. 7 CFR 983.150 - Aflatoxin regulations.

    Science.gov (United States)

    2010-01-01

    ..., ARIZONA, AND NEW MEXICO Rules and Regulations § 983.150 Aflatoxin regulations. (a) Maximum level. No... within the production area are exempt from the aflatoxin regulation of this section. (d) Aflatoxin... and analyzed using High Pressure Liquid Chromatograph (HPLC), Vicam Method (Aflatest), or other...

  17. 7 CFR 983.50 - Aflatoxin regulations.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Aflatoxin regulations. 983.50 Section 983.50..., ARIZONA, AND NEW MEXICO Regulations § 983.50 Aflatoxin regulations. The committee shall establish, with the approval of the Secretary, such aflatoxin sampling, analysis, and inspection requirements...

  18. Simple buck/boost voltage regulator

    Science.gov (United States)

    Paulkovich, J.; Rodriguez, G. E.

    1980-01-01

    Circuit corrects low or high supply voltage, produces regulated output voltage. Circuit has fewer components because inductory/transformer combination and pulse-width modulator serve double duty. Regulator handles input voltage variation from as low as one half output voltage to as high as input transistor rating. Solar arrays, fuel cells, and thermionic generators might use this regulator.

  19. 10 CFR 850.26 - Regulated areas.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Regulated areas. 850.26 Section 850.26 Energy DEPARTMENT... Regulated areas. (a) If airborne concentrations of beryllium in areas in DOE facilities are measured at or above the action level, the responsible employer must establish regulated areas for those areas. (b)...

  20. Becoming an Engaged, Self-Regulated Reader.

    Science.gov (United States)

    Horner, Sherri L.; Shwery, Craig S.

    2002-01-01

    Explains how students self-regulate while reading, describing students' personal beliefs of self-efficacy, task value, and motivation and how these beliefs influence their self- regulated reading; discussing the processes of self-regulated reading (goal setting; selection, use, and monitoring of reading strategies; and self-evaluation); and…

  1. 46 CFR 310.67 - Academy regulations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Academy regulations. 310.67 Section 310.67 Shipping... Training of Midshipmen at the United States Merchant Marine Academy § 310.67 Academy regulations. The Superintendent of the Academy is delegated authority to issue all regulations necessary for the accomplishment of...

  2. The Goals for Regulating College Tuition

    Science.gov (United States)

    Zeng, Xiaodong

    2009-01-01

    Regulation refers to governmental restrictions over enterprise in order to protect public interest. Research on governmental regulation in China primarily focuses on public utility, and inadequate attention has been paid to regulating college tuition. Currently, although the educational administrative agencies have successfully kept college…

  3. Good Practice Standards – a Regulation Tool

    DEFF Research Database (Denmark)

    Sørensen, Marie Jull

    2013-01-01

    The purpose of this article is to identify the considerations weighed in regulation with good practice standards. In this article, potential due process problems with regulation via legal standards are identified and compared to other considerations, which this regulation technique meets....

  4. 76 FR 62630 - Information Security Regulations

    Science.gov (United States)

    2011-10-11

    ... 32 CFR Part 1902 Information Security Regulations AGENCY: Central Intelligence Agency. ACTION: Final rule. SUMMARY: The Central Intelligence agency is removing certain information security regulations... Information security regulations. PART 1902 Sec. 1902.13 0 Accordingly, under the authority of Executive...

  5. Regulated trafficking of the CFTR chloride channel

    NARCIS (Netherlands)

    Braakman, L.J.; Kleizen, B.; Jonge, H.R. de

    2000-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR), the ABC transporter encoded by the cystic fibrosis gene, is localized in the apical membrane of epithelial cells where it functions as a cyclic AMP-regulated chloride channel and as a regulator of other ion channels and transporters. Wh

  6. 31 CFR 308.4 - Applicable regulations.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Applicable regulations. 308.4 Section 308.4 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT GENERAL REGULATIONS GOVERNING FULL-PAID...

  7. Regulations Protect Right of Disabled to Employment

    Institute of Scientific and Technical Information of China (English)

    NING LILI

    2007-01-01

    @@ On February 14, 2007, the 169th Executive Meeting of the State Council, China's central government, adopted the Regulations on Employment of the Disabled (hereinafter referred to as the Regulations). The Regulations, which became effective on May 1,comes as an important guarantee for the right of the disabled to work.

  8. 7 CFR 984.49 - Volume regulation.

    Science.gov (United States)

    2010-01-01

    ... Regulating Handling Marketing Policy § 984.49 Volume regulation. (a) Free, reserve, and export percentages... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... during a marketing year will tend to effectuate the declared policy of the act, he shall establish a...

  9. Regulation of BLM Nucleolar Localization

    Science.gov (United States)

    Tangeman, Larissa; McIlhatton, Michael A.; Grierson, Patrick; Groden, Joanna; Acharya, Samir

    2016-01-01

    Defects in coordinated ribosomal RNA (rRNA) transcription in the nucleolus cause cellular and organismal growth deficiencies. Bloom’s syndrome, an autosomal recessive human disorder caused by mutated recQ-like helicase BLM, presents with growth defects suggestive of underlying defects in rRNA transcription. Our previous studies showed that BLM facilitates rRNA transcription and interacts with RNA polymerase I and topoisomerase I (TOP1) in the nucleolus. The mechanisms regulating localization of BLM to the nucleolus are unknown. In this study, we identify the TOP1-interaction region of BLM by co-immunoprecipitation of in vitro transcribed and translated BLM segments and show that this region includes the highly conserved nuclear localization sequence (NLS) of BLM. Biochemical and nucleolar co-localization studies using site-specific mutants show that two serines within the NLS (S1342 and S1345) are critical for nucleolar localization of BLM but do not affect the functional interaction of BLM with TOP1. Mutagenesis of both serines to aspartic acid (phospho-mimetic), but not alanine (phospho-dead), results in approximately 80% reduction in nucleolar localization of BLM while retaining the biochemical functions and nuclear localization of BLM. Our studies suggest a role for this region in regulating nucleolar localization of BLM via modification of the two serines within the NLS. PMID:27657136

  10. Human morphology and temperature regulation

    Science.gov (United States)

    Anderson, G. S.

    For nearly a century individuals have believed that there is a link between human morphology and one's thermoregulatory response in adverse environments. Most early research was focussed on the rate of core cooling in a male adult population and the role of subcutaneous adipose tissue, surface area and the surface-area-to-mass ratio in one's ability to withstand varying degrees of cold stress. More recently research has addressed heat tolerance in various populations, exploring the role of subcutaneous adipose tissue, surface area and the surface-area-to-mass ratio in one's ability to maintain thermal equilibrium in warm and hot, dry and humid environments. Since the late 1970s an emphasis has been placed on the role of muscle and muscle perfusion in total-body thermal insulation. Yet, despite the history of research pertaining to human morphology and temperature regulation there is little consensus as to the impact of variations in human morphology on thermoregulatory responses. Individuals differing in body size, shape and composition appear to respond quantitatively differently to variations in both ambient and core temperatures but the interrelations between morphological components and temperature regulation are complex. It is the purpose of this paper to examine the literature pertaining to the impact of variations in muscularity, adipose tissue thickness and patterning, surface area and the surface-area-to-mass ratio on thermoregulation and thermal stability in response to both heat and cold stress.

  11. Chromatin structure regulates gene conversion.

    Directory of Open Access Journals (Sweden)

    W Jason Cummings

    2007-10-01

    Full Text Available Homology-directed repair is a powerful mechanism for maintaining and altering genomic structure. We asked how chromatin structure contributes to the use of homologous sequences as donors for repair using the chicken B cell line DT40 as a model. In DT40, immunoglobulin genes undergo regulated sequence diversification by gene conversion templated by pseudogene donors. We found that the immunoglobulin Vlambda pseudogene array is characterized by histone modifications associated with active chromatin. We directly demonstrated the importance of chromatin structure for gene conversion, using a regulatable experimental system in which the heterochromatin protein HP1 (Drosophila melanogaster Su[var]205, expressed as a fusion to Escherichia coli lactose repressor, is tethered to polymerized lactose operators integrated within the pseudo-Vlambda donor array. Tethered HP1 diminished histone acetylation within the pseudo-Vlambda array, and altered the outcome of Vlambda diversification, so that nontemplated mutations rather than templated mutations predominated. Thus, chromatin structure regulates homology-directed repair. These results suggest that histone modifications may contribute to maintaining genomic stability by preventing recombination between repetitive sequences.

  12. Nickel-responsive transcriptional regulators.

    Science.gov (United States)

    Musiani, Francesco; Zambelli, Barbara; Bazzani, Micaela; Mazzei, Luca; Ciurli, Stefano

    2015-09-01

    Nickel is an essential micronutrient for a large number of living organisms, but it is also a toxic metal ion when it accumulates beyond the sustainable level as it may result if and when its cellular trafficking is not properly governed. Therefore, the homeostasis and metabolism of nickel is tightly regulated through metal-specific protein networks that respond to the available Ni(II) concentration. These are directed by specific nickel sensors, able to couple Ni(II) binding to a change in their DNA binding affinity and/or specificity, thus translating the cellular level of Ni(II) into a modification of the expression of the proteins devoted to modulating nickel uptake, efflux and cellular utilization. This review describes the Ni(II)-dependent transcriptional regulators discovered so far, focusing on their structural features, metal coordination modes and metal binding thermodynamics. Understanding these properties is essential to comprehend how these sensors correlate nickel availability to metal coordination and functional responses. A broad and comparative study, described here, reveals some general traits that characterize the binding stoichiometry and Ni(II) affinity of these metallo-sensors.

  13. VOLTAGE REGULATORS OF SYNCHRONOUS GENERATORS

    Directory of Open Access Journals (Sweden)

    Grigorash O. V.

    2015-06-01

    Full Text Available Synchronous generators are the primary source of electrical power autonomous electrosupply systems, including backup systems. They are also used in a structure of rotating electricity converters and are widely used in renewable energy as part of wind power plants of small, mini and micro hydroelectric plants. Increasing the speed and the accuracy of the system of the voltage regulation of synchronous generators is possible due to the development of combined systems containing more stabilizers. The article illustrates the functional schemes of circuit voltage stabilizers and frequency synchronous generators (with electromagnetic excitation and permanent magnet excitation and describes the features of their work, including two and three-aggregate rotating converters of electricity used in uninterruptible power supply systems. To improve the technical characteristics of the system of stabilization we have proposed functional solutions for stabilizers of synchronous generators made on the base of direct frequency converters and using a transformer with a rotating magnetic field. To improve the reliability of and to improve the operational characteristics of the autonomous independent sources of electricity we suggest creating the main functional blocks and the elements of the stabilization system in a modular way. The functional circuit solutions of voltage regulators of synchronous generators and the characteristics of their work considered in the article, are able to improve the efficiency of pre-design work in the development of new technical solutions for stabilizing the voltage and the frequency in synchronous generators of electrosupply autonomous systems

  14. CPG OLIGONUCLEOTIDES REGULATE OSTEOCLAST DIFFERENTIATION

    Institute of Scientific and Technical Information of China (English)

    Zhao Weigong; Han Xuezhe; Li Xinyou; Guo Xong; Liu Miao

    2005-01-01

    Objective Bacterial DNA is a pathogen-derived molecule which can regulate the innate immune system by stimulating NF-κB activation. The activity of bacterial DNA relies on its content of unmethylated CpG dinucleotides in particular base contexts("CpG motif"). In light of the pivotal role played by NF-κB in osteoclast differentiation, the ability of CpG oligodeoxynucleotides (CpG ODN) coming from bacterial DNA to modulate osteoclastogenesis was studied. Methods Bone marrow mononuclear cells (BMM) were purified from Balb/c mice, cultured in α-MEM media containing 10% FCS in the presence of mouse M-CSF, with either RANKL or ODNs for 5 days. Osteoclast formation was evaluated on day 5 according to TRAP and May-Grunwald-Giemsa staining. Results CpG ODN alone could induce osteoclast formation in the low degree in BMM culture. The relationship between CpG ODN and RANKL was that CpG ODN could inhibit RANKL-induced osteoclastogenesis when present from the beginning of BMM culture, but strongly increased RANKL-induced osteoclastogenesis in RANKL-pretreated BMMs. Conclusion The mechanism of CpG ODN regulating osteoclast differentiation was bidirectional, which might be a potential therapy for treating metabolic bone disease.

  15. Central regulation of sodium appetite.

    Science.gov (United States)

    Geerling, Joel C; Loewy, Arthur D

    2008-02-01

    Sodium appetite, the behavioural drive to ingest salt, is stimulated by prolonged physiological sodium deficiency in many animal species. The same neural mechanisms that are responsible for sodium appetite in laboratory animals may influence human behaviour as well, with particular relevance to the dietary salt intake of patients with diseases such as heart failure, renal failure, liver failure and salt-sensitive hypertension. Since the original experimental work of Curt Richter in the 1930s, much has been learned about the regulation of salt-ingestive behaviour. Here, we review data from physiology, pharmacology, neuroanatomy and neurobehavioural investigations into the stimulatory and inhibitory signals that regulate sodium appetite. A rudimentary framework is proposed for the brain circuits that integrate peripheral information representing the need for sodium with neural signals for the gustatory detection of salt in order to drive a motivated ingestive response. Based on this model, areas of remaining uncertainty are highlighted where future information would allow a more detailed understanding of the neural circuitry responsible for sodium appetite.

  16. A laser tube position regulator

    Energy Technology Data Exchange (ETDEWEB)

    Sinyitiro, A.; Norio, K.

    1984-03-26

    An improved design is patented for a mechanism and method of regulating, with a high degree of accuracy, the position of a laser tube in a gas laser inside the optical resonator formed by external mirrors. The laser tube is held in two holders. Each holder contains an L shaped bracket which supports a semitransparent plate. The plate is positioned so that its center is over the center of the end of the tube which is in the form of a Brewster window. A narrow parallel beam is directed along the tube axis from an external auxiliary laser. The beam passes through the semitransparent mirror of the optical resonator in the adjusted laser, through the first Brewster window, the tube itself, and the second Brewster window and is reflected back in the reverse direction from a fully reflecting mirror in the optical resonator. This provides partial reflection of the beam from the external Brewster mirror surface. The tube position in the holders is regulated continuously so that the luminous spots from the beams reflected off the Brewster windows fall on the semitransparent plates in the center of the latter which is designated as the point of intersection.

  17. Uncommon Trimethoxylated Flavonol Obtained from Rubus rosaefolius Leaves and Its Antiproliferative Activity

    Directory of Open Access Journals (Sweden)

    Marcel Petreanu

    2015-01-01

    Full Text Available This study shows the evaluation the antiproliferative effect of the extract, fractions, and uncommon compounds isolated from R. rosaefolius leaves. The compounds were identified by conventional spectroscopic methods such as NMR-H1 and C13 and identified as 5,7-dihydroxy-6,8,4′-trimethoxyflavonol (1, 5-hydroxy-3,6,7,8,4′-pentamethoxyflavone (2, and tormentic acid (3. Both hexane and dichloromethane fractions showed selectivity for multidrug-resistant ovary cancer cell line (NCI-ADR/RES with total growth inhibition values of 11.1 and 12.6 μg/ml, respectively. Compound 1 also showed selective activity against the same cell line (18.8 μg/ml; however, it was especially effective against glioma cells (2.8 μg/ml, suggesting that this compound may be involved with the in vitro antiproliferative action.

  18. Novel Flavonol Glycosides from the Aerial Parts of Lentil (Lens culinaris

    Directory of Open Access Journals (Sweden)

    Jerzy Żuchowski

    2014-11-01

    Full Text Available While the phytochemical composition of lentil (Lens culinaris seeds is well described in scientific literature, there is very little available data about secondary metabolites from lentil leaves and stems. Our research reveals that the aerial parts of lentil are a rich source of flavonoids. Six kaempferol and twelve quercetin glycosides were isolated, their structures were elucidated using NMR spectroscopy and chemical methods. This group includes 16 compounds which have not been previously described in the scientific literature: quercetin 3-O-β-D-glucopyranosyl(1→2-β-D-galactopyranoside-7-O-β-D-glucuropyranoside (1, kaempferol 3-O-β-D-glucopyranosyl(1→2-β-D-galacto-pyranoside-7-O-β-D-glucuropyranoside (3, their derivatives 4–10,12–15,17,18 acylated with caffeic, p-coumaric, ferulic, or 3,4,5-trihydroxycinnamic acid and kaempferol 3-O-{[(6-O-E-p-coumaroyl-β-D-glucopyranosyl(1→2]-α-L-rhamnopyranosyl(1→6}-β-D-galactopyranoside-7-O-α-L-rhamnopyranoside (11. Their DPPH scavenging activity was also evaluated. This is probably the first detailed description of flavonoids from the aerial parts of lentil.

  19. A hydroxylated flavonol, fisetin inhibits the formation of a carcinogenic estrogen metabolite.

    Science.gov (United States)

    Meng, Xin; Sun, Hui; Yang, Lianrong; Yin, Rui; Qi, Lehui

    2017-03-01

    Fisetin can be found in a wide variety of plants and possesses strong efficacy against many cancers. 17β-Estradiol (E2) is hydrolyzed to 4-hydroxy-E2 (4-OHE2) via cytochrome P450 (CYP) 1B1 in vivo. In estrogen target tissues including the mammary gland, ovaries, and uterus, CYP1B1 is highly expressed, and 4-OHE2 is predominantly formed in cancerous tissues. Herein, we investigated the inhibitory activity of fisetin and flavone against CYP1B1 using estrogen E2 as substrate in vitro to reveal structure-activity relationship between structure of flavonoids and inhibition. The results showed that fisetin possessed inhibitory effect on CYP1B1 activity. Compared with flavone, the inhibition of fisetin was stronger. The Vmax and Ki values were 1.950±0.157pmol/μgprotein/min and 4.925±0.689nM for fisetin and 2.277±0.231pmol/μgprotein/min and 9.148±2.150nM for flavone, respectively. By kinetic analyses, both fisetin and flavone displayed mixed inhibition. Taken together the data suggested that fisetin is able to inhibit the formation of carcinogenic 4-OHE2 from E2, which reveals one of its anti-cancer mechanisms and helps to reveal the relationship between the structure of flavonoids and the inhibition CYP1B1 for discovering new drugs in cancer therapy and prevention. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. O-Methylated flavonol isorhamnetin prevents acute inflammation through blocking of NF-κB activation.

    Science.gov (United States)

    Yang, Ji Hye; Kim, Sang Chan; Shin, Bo Yeon; Jin, So Hee; Jo, Mi Jeong; Jegal, Kyung Hwan; Kim, Young Woo; Lee, Jong Rok; Ku, Sae Kwang; Cho, Il Je; Ki, Sung Hwan

    2013-09-01

    Here, we isolated isorhamnetin, a natural 3'-O-methylated flavonoid, from water dropwort (Oenanthe javanica, Umbelliferae) and investigated its ability to protect against acute inflammation in vivo and in vitro. To induce paw swelling, the hind paw of each rat was injected with a carrageenan 1h after vehicle or isorhamnetin treatment. In vitro effect and mechanism studies were performed in lipopolysaccharide (LPS)-activated macrophages. Administration of isorhamnetin markedly inhibited the swelling volume and the thickness of hind paws. Moreover, isorhamnetin significantly reduced inflammatory cell infiltration and pro-inflammatory gene expression in rats. Isorhamnetin pretreatment inhibited inducible nitric oxide synthase (iNOS) expression and NO release in LPS-stimulated cells. Activation of nuclear factor-kappa B (NF-κB) and activating protein-1 (AP-1) is the key step in the iNOS gene induction. Isorhamnetin specifically inhibited NF-κB luciferase activity, but not AP-1. Pretreatment with isorhamnetin suppressed NF-κB nuclear translocation in accordance with decreased phosphorylation and degradation of inhibitory-κB. Consistently, TNF-α, IL-1β and IL-6 expression, representative NF-κB target genes, were almost completely prohibited by isorhamnetin. Furthermore, isorhamnetin inhibited LPS-induced JNK and AKT/IKKα/β phosphorylation. Our results suggest that isorhamnetin inhibited JNK, and AKT/IKKα/β activation, leading to NF-κB inactivation, which might contribute to the inhibition of the acute inflammatory response.