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1.
Reactive oxygen species (ROS) have been widely known to inflict biological damage upon a variety of biological sites. The ability to counteract any such activity has been the subject of this work, in an attempt to comprehend prooxidant metal ion induced oxidation and its possible physiological consequences. Five Mediterranean aqueous herb infusions have been employed in the investigation of possible pro/antioxidant activity promoted by prooxidant iron ions. In the presence of phospholipid liposomes or linoleic acid micelles or 2-deoxy-d-ribose, it was shown that all of the aqueous infusions used exhibited antioxidant activity in comparison to the iron control. The antioxidant activity, studied on 2-deoxy-d-ribose, at three concentration levels in each herb, appears to be dose dependent, albeit non-linear. The total polyphenol content of the investigated herb infusions, however, does not directly correlate with the observed antioxidant activity. The variable, yet effective, antioxidant capacity of the aqueous infusions indicates that their antioxidant components can quench ROS generating activity, brought on different substrates and likely arisen by variable mechanisms involving different ROS. 相似文献
2.
《Bioscience, biotechnology, and biochemistry》2013,77(7):1380-1385
The amounts and compositions of polyphenol in persimmon leaves and persimmon leaf tea were investigated. The predominant polyphenols in fresh leaves were water-soluble, and the contents reached a maximum (2.40% w/w) in June, and then gradually decreased. Separation of them followed by thiolytic degradation revealed that the major components were unique proanthocyanidin oligomers consisting of four heterogeneous extension units, including epigallocatechin-3-O-gallate. Persimmon leaf tea also contained similar proanthocyanidins with similar compositional units. Oral administration of starch with polyphenol concentrate of persimmon leaf tea resulted in a significant and dose-dependent decrease in the blood glucose level in Wistar rats. This effect is considered to be due to inhibition of pancreas α-amylase. These results indicate that persimmon leaf tea containing peculiar proanthocyanidins has a significant role in suppressing blood glucose elevation after starch intake, and that the best harvest time is June. 相似文献
3.
《Bioscience, biotechnology, and biochemistry》2013,77(2):598-602
Rooibos tea was extracted with boiling water. The aqueous extract was chromatographed in a Diaion HP20 column eluted stepwise with water, 25%, 50% and 75% (v/v) aqueous methanol, and 100% methanol. The water eluate (fraction A) showed an augmenting effect on anti-ovalbumin (anti-OVA) immunoglobulin M (IgM) production in OVA-stimulated murine splenocytes in vitro. Fraction A also showed a strong augmenting effect on interleukin-10 generation in murine splenocytes. Furthermore, continuous ingestion of fraction A was found to increase the anti-OVA IgM level in the sera of OVA-immunized mice. 相似文献
4.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2023-2033
A series of 1,2-dithiolanes, 1,2-dithianes and related compounds bearing a nitrogen-containing substituent were synthesized and their pesticidal activity was tested. A new general synthetic route to 1,2-dithiolanes was established from 1,3-diols. A variation in the position and character of the nitrogen atom is shown to be allowable to some extent for promoting insecticidal activity, unlike the case of sulfur atoms. Most compounds showed acaricidal activity, the strongest being displayed by cis-3,5-bis(dimethylaminomethyl)-1,2-dithiolane. 相似文献
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6.
《Chemical Speciation and Bioavailability》2013,25(4):163-173
ABSTRACTTotal aluminum, arsenic, calcium, cadmium, iron, lead, potassium, magnesium, nickel and zinc were determined in black tea by electro thermal atomic absorption spectrometry after ultrasonic assisted pseudo-digestion with mixture of acid and oxidant. All the metals were also determined in the tea infusions in order to know the percentage of each element leached into the liquor. A conventional acid digestion on electric hot plate was used to obtain total metals under study for comparative purpose. Analytical results for Al, As, Ca, Cd, Fe, K, Mg, Ni, Pb and Zn obtained by ultrasound assisted pseudodigestion, and conventional wet digestion methods showed a good agreement, thus indicating the possibility of using ultrasonic assisted digestion sample preparation instead of intensive treatments inherent with the acid digestion methods on electric hot plate. The validity and accuracy of both procedures were checked by using certified sample of NIES No. 7 (Tea Leaves). Non significant differences were observed for P>0.05 when comparing the values obtained by both methods (paired t-test).Principal component analysis (PCA) was applied in order to determine the different amount of metals as main sources of variability in the data sets and to establish the relation between samples (branded and nonbranded tea samples) and micronutrient, trace and toxic metals (variables). Hierarchical cluster analysis (HCA) was used to explore the different branded and nonbranded tea samples grouping according to the essential and toxic metals as additional information to the out put obtained by PCA. 相似文献
7.
《Bioscience, biotechnology, and biochemistry》2013,77(3):626-631
A practical method for universal evaluation of the astringency of green tea infusion by a taste sensor system was established. The use of EGCg aqueous solution as a standard enabled analysis with high accuracy and reproducibility. The sensor output was converted into taste-intensity on the basis of Weber’s and Weber-Fechner laws, which was named the “EIT ast ” value (“EIT” and “ast” are abbreviations for “Estimated Intensity of Taste” and “astringency” respectively). It was clarified that green tea infusion is to be classified into eight grades on the EIT ast scale. Furthermore, the high correlation of the EIT ast value with the human gustatory sense and the high stability of the taste sensor were proved. 相似文献
8.
《Journal of Plant Interactions》2013,8(3):169-174
Abstract A psychrotolerant, halotolerant and alkalophilic yeast was isolated from fermented leaves of Camellia sinensis Kuntze, the tea plant. The yeast strain, named Tea-Y1, was both phenotypically and genotypically identified as belonging to the species Debaryomyces hansenii. This assignment was confirmed by scanning and transmission electron microscopy. The analysis of growth curves demonstrated the ability this yeast strain to grow in a temperature range between 4°C and 28°C, with an optimum of 23°C. The ecology of this yeast in the C. sinensis phyllosphere, as well as its possible role in tea fermentation and storage, with particular reference to iced tea, are discussed. 相似文献
9.
《Bioscience, biotechnology, and biochemistry》2013,77(8):1606-1612
We manufactured a new fermented tea by tea-rolling processing of third-crop green tea (Camellia sinensis) leaves and loquat (Eriobotrya japonica) leaves. The mixed fermented tea extract inhibited pancreatic lipase activity in vitro, and effectively suppressed postprandial hypertriacylglycerolemia in rats. Rats fed a diet containing 1% freeze-dried fermented tea extract for 4 weeks had a significantly lower liver triacylglycerol concentration and white adipose tissue weight than those fed the control diet lacking fermented tea extract. The activity of fatty acid synthase in hepatic cytosol markedly decreased in the fermented tea extract group as compared to the control group. The serum and liver triacylglycerol- and body fat-lowering effects of the mixed fermented tea extract were strong relative to the level of dietary supplementation. These results suggest that the new fermented tea product exhibited hypotriacylglycerolemic and antiobesity properties through suppression of both liver fatty acid synthesis and postprandial hypertriacylglycerolemia by inhibition of pancreatic lipase. 相似文献
10.