Transgenic tobacco (Nicotiana tabacum L.) plants overexpressing the enzyme L-phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) were grown from seeds of a primary transformant containing the bean PAL2 ...gene, which had shown homology-dependent silencing of the endogenous tobacco PAL genes. Analysis of endogenous and transgene-encoded PAL transcripts and protein in the primary transformant (T0) and first-generation (T1) overexpressor plants indicated that the transgene-encoded PAL is the cause of the greater than wild-type levels of PAL activity (up to 5- and 2-fold greater in leaf and stem tissue, respectively) in the T1 plants. Leaves of PAL-overexpressing plants contained increased levels of the hydroxycinnamic acid ester chlorogenic acid but not of the flavonoid rutin, indicating that PAL is the key control point for flux into chlorogenic acid. In addition, levels of the glucoside of 4-coumaric acid increased in the overexpressing plants, suggesting that the 4-coumarate:coenzyme A ligase or coumarate hydroxylase reactions might have become limiting. These results help to define the regulatory architecture of the phenylpropanoid pathway and indicate the possibility of engineering-selective changes in this complex metabolic pathway by overexpression of a single early pathway gene
It was hypothesized that buckwheat, especially its flowers, influences foregut fermentation in ruminant animals because it is rich in phenolic compounds. The entire fresh aerial buckwheat herb, or ...its parts (leaves, stems, flowers and grain), were incubated for 24 h together with pure ryegrass (1:1, dry matter basis) in an in vitro ruminal fermentation system (Hohenheim Gas Test). Additionally ryegrass, supplemented with 0, 0.5, 5, or 50 mg rutin trihydrate/g dry matter, was incubated. Concentrations of extractable phenols (g/kg dry matter) were the highest in buckwheat flowers (88), followed by leaves (63), and the lowest in ryegrass (8). The levels of production of total gas and volatile fatty acids demonstrated that the nutritional value of buckwheat was slightly lower than that of ryegrass. Compared to ryegrass alone, ruminal transformation of dietary protein-N into ammonia was lower with 50 mg rutin, buckwheat flowers and buckwheat leaves. Thus, these treatments appeared to have partly protected dietary protein from ruminal degradation. Rutin, at the highest level, buckwheat flowers and the total aerial fraction of the buckwheat plant suppressed methane per unit of total gas by more than 10%, either at elevated (rutin) or reduced total gas volume. This indicates that the ways of the influence on the ruminal fermentation pattern differed between pure rutin and buckwheat.
Korean Sophora japonica has been found to posses an anti-inflammatory activity. In this study, Korean Sophora japonica extract, rutin, was used to know whether rutin inhibits to produce inflammatory ...mediators NO and TNF-α from the mouse peritoneal macrophages that were treated an inflammatory agent LPS. The rutin-1 hr pretreated macrophages were incubated with LPS for 0.5~5 hrs, and then collected the supernatant and the cell lysate for measurements of the level of iNOS, NO, TNF-α mRNA, TNF-α, and p-NF-κB. Minimal and maximal effective doses of the rutin on them were 1 and 100 ㎍/㎖, respectively. The maximal effective dose of rutin certainly inhibted the productions of iNOS, NO, TNF-α mRNA, TNF-α and p-NF-κB from the LPS-treated macrophages (p less than 0.0001). Its ED∧50 for inhibition of TNF-α mRNA and p-NF-κB was 5 ㎍/㎖, and for iNOS, NO, and TNF-α was 10 ㎍/㎖. The rutin did not have any cytotoxic effect. As the results, the Sophora japonica rutin could be a good candidate for an anti-inflammatory action.
The aim of this investigation was to examine the influence of extrusion on dietary fiber profile and the content of bioactive compounds, rutin and quercetin in young sprout, whole seed, and matured ...stem of Tartary buckwheat. WSI(water soluble index) is increased by a function of both screw profile and process temperature, compared to control in different parts of Buckwheat. Also, WSI of ME is increased more than 5.2 times in grain, compared to that of control. The effect of precooking by extrusion on the dietary fiber profile of buckwheat flour was evaluated. Precooking by extrusion significantly increased SDF in flour, although in most cases extrusion decrease in TDF a little. The thermo-mechanical treatment undergone by the buckwheat flour during extrusion led to redistribute part IDF fraction to SDF, leading to an increase in the latter. The content of rutin was increased about two fold in extruded flour of sprout, compared to in control. This increase maybe why these compounds are released from cell wall by high shear processing under high temperature.
Phenylalanine ammonia-lyase (PAL) catalyzes the first step in phenylpropanoid synthesis. The role of PAL in pathway regulation was investigated by measurement of product accumulation as a function of ...enzyme activity in a collection of near-isogenic transgenic tobacco plants exhibiting a range of PAL levels from wild type to 0.2% of wild type. In leaf tissue, PAL level is the dominant factor regulating accumulation of the major product chlorogenic acid and overall flux into the pathway. In stems, PAL at wild-type levels contributes, together with downstream steps, in the regulation of lignin deposition and becomes the dominant, rate-determining step at levels 3- to 4-fold below wild type. The metabolic impact of elevated PAL levels was investigated in transgenic leaf callus that overexpressed PAL. Accumulation of the flavonoid rutin, the major product in wild-type callus, was not increased, but several other products accumulated to similarly high levels. These data indicate that PAL is a key step in the regulation of overall flux into the pathway and, hence, accumulation of major phenylpropanoid products, with the regulatory architecture of the pathway poised so that downstream steps control partitioning into different branch pathways.
Eight catechins reduced the color of a monoglucosyl rutin solution, the gallate-type catechins having a greater effect than the non-gallate-type catechins. Each catechin formed a 1:1 complex with ...monoglucosyl rutin. The binding constants of the gallate-type catechins were larger than those of the non-gallate type. These results indicate that the degree of color change in the monoglucosyl rutin solution depended on the ability of each catechin to form a complex with monoglucosyl rutin.
Thirteen isoflavonoids, flavonoids, and lignans, including some known phytoestrogens, were evaluated for their effects on DNA synthesis in estrogen-dependent (MCF-7) and -independent (MDA-MB-231) ...human breast cancer cells. Treatment for 24 hours with most of the compounds at 20-80 micromolar sharply inhibited DNA synthesis in MDA-MB-231 cells. In MCF-7 cells, on the other hand, biphasic effects were seen. At 0.1-10 micromolar, coumestrol, genistein, biochanin A, apigenin, luteolin, kaempferol, and enterolactone induced DNA synthesis 150-235% and, at 20-90 micromolar, inhibited DNA synthesis by 50%. Treatment of MCF-7 cells for 10 days with genistein or coumestrol showed continuous stimulation of DNA synthesis at low concentrations. Time-course experiments with genistein in MCF-7 cells showed effects to be reversed by 48-hour withdrawal of genistein at most concentrations. Induction of DNA synthesis in MCF-7 cells, but not in MDA-MB-231 cells, is consistent with an estrogenic effect of these compounds. Inhibition of estrogen-dependent and -independent breast cancer cells at high concentrations suggests additional mechanisms independent of the estrogen receptor. The current focus on the role of phytoestrogens in cancer prevention must take into account the biphasic effects observed in this study, showing inhibition of DNA synthesis at high concentrations but induction at concentrations close to probable levels in humans
Comparison of Czech hop cultivars based on their contents of secondary metabolites Jelinek, L.,Vysoka Skola Chemicko-technologicka, Prague (Czech Republic). Ustav Kvasne Chemie a Bioinzenyrstvi; Sneberger, M.,Vysoka Skola Chemicko-technologicka, Prague (Czech Republic). Ustav Kvasne Chemie a Bioinzenyrstvi; Karabin, M.,Vysoka Skola Chemicko-technologicka, Prague (Czech Republic). Ustav Kvasne Chemie a Bioinzenyrstvi ...
Czech Journal of Food Sciences,
01/2010, Letnik:
28, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Seven Czech hop varieties (dry hop cones) coming from the harvest of 2008 (Agnus, Bor, Harmonie, Premiant, Rubin, Sladek, and Saaz) were compared for their composition depending on their varietal ...differentiation. These cultivars were analysed for the contents of alpha- and beta-bitter acids analogues, essential oils, and polyphenols. Hop essential oil constituents significantly contribute to the individual hop varieties. The dichotomous key for the authentication of Czech hop varieties was established based on some characteristic varietal markers.
The use of tartary buckwheat flour as a source of dietary rutin has been limited because of the enzymatic degradation of rutin during the dough-making process, which results in a bitter taste. A ...variety of pretreatment regimes, including heating, steaming, boiling, and extruding, were evaluated in relation to the inactivation of the rutin-degrading enzyme responsible for rutin loss and color change during dough-making. Steaming (120 sec), boiling (90 sec) buckwheat grains, or extruding (180 rpm/min at 140℃) the flour resulted in the retention of greater than 85% of the original rutin and eliminated the bitter taste in the hydrated flours. In contrast, dry heating at 140℃ for 9 min or microwaving at 2,450 MHz for 3 min did not reduce the rutin loss, and the bitter taste remained. Unlike in the flour, the rutin degradation in water-soaked grains was insignificant at room temperature. Moreover, the samples treated by steaming, boiling, or extrusion were darker and more reddish in color.
The genus Hypericum L. (St. John's-wort, Hypericaceae) has received scientific interest in recent years, because it is a source of a variety of bioactive compounds including the phenolics. We ...determine whether the typical phenolic constituents of Hypericum plants, namely chlorogenic acid, rutin, hyperoside, isoquercetine, quercitrine, and quercetine, may be implicated as part of an inducible plant defence response in two St. John's-wort species, Hypericum perforatum L. and Hypericum triquetrifolium Turra. To achieve this objective, greenhouse-grown plantlets were inoculated with the fungal pathogen Diploceras hypericinum and the plant growth promoting bacterium Pseudonomas putida. Phenolic compounds levels of the Hypericum plantlets increased significantly in response to inoculation with both organisms. So far, little effort has been dedicated to investigate whether phenolic compounds are inducible by pathogen/herbivore attack or if they could play a role in plant defence. Results from the study indicate that the phenolic compounds investigated could be involved in the plant defence system and implicated as part of an inducible plant defence response in both St. John's Wort species.
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