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date, bamboo leaf extract has been reported to exhibit antioxidant, antibacterial, antitumor, anti-inflammatory, antimicrobial, and antiulcerogenic activities [ 2 – 6 ]. Phytochemical research on PES leaves has revealed the functions of 4 flavonoids and

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been officially certified as a natural food additive by the Chinese Ministry of Health [ 3, 4 ]. Flavonoids, phenolic acids, and coumaric lactones are the main bioactive components in BLE, and the flavonoid constituents are diverse and present at high

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. investigated that essential oil and total flavonoids of O. falcata showed antiproliferative activity on SMMC-7721 through down-regulating secretion and expression of MMP-2 in cells [ 6 ]. Yang et al. reported that total flavonoid of O. falcata is a pro

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Dixon, R. A., Xie, D.-Y., Sharma, S. B. (2005) Proanthocyanidins — a final frontier in flavonoid research? New Phytol. 165 , 9–28. Sharma S. B. Proanthocyanidins — a final frontier in

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Fruits are rich sources of flavonoid polyphenolic compounds that seem to be associated with favourable healtheffects. Commonalities and differences are well known in the flavonoid contents of different fruit crops, which suggest alterations in the flavonoid biosynthesis pathway of fruit tissues. This review aims to collect data from molecular genetic studies on the structural and regulatory genes in grape, berries, citrus, pomes and stone fruits to get impression on the state of the art of this field of science. Results indicate that the expression of flavonoid genes is a genotype-dependent and developmentally regulated process. In addition, genetic alterations resulting in specific changes in flavonoid composition are also highlighted. Analysis of colour mutants of grape, bilberry and orange identified the genes responsible for the altered phenotype, and this strategy might offer valuable tools to identify several other candidate genes in different fruits. The application of such data is also discussed in relation with the development of molecular markers.

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This study, carried out in 2004–2005, describes the variation of hypericin and flavonoid contents in different samples of Hypericum maculatum . Flowering tops of H. maculatum were collected and analysed for hypericin and flavonoids using HPLC. The contents of hypericin ranged from 0.35–0.95 mg/g; flavonoid contents varied as follows: hyperoside — 16.66–40.89 mg/g, quercitrin — 0.00 to 1.07 mg/g and quercetin — 1.46–4.96 mg/g. The study indicated that flavonoid rutin was absent from the flavonoid pattern of H. maculatum , or present only in trace amounts (0.00–0.67 mg/g), however, H. maculatum is one of the most important sources of hyperoside. The samples of H. maculatum which accumulated high levels of flavonoids seem to be promising for further propagation.

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Summary

Scutellaria L. is a diverse genus of the Lamiaceae (Labiatae) family of over 300 herbaceous plants commonly known as skullcaps. Various species of Scutellaria are used as ethnobotanical herbs for the treatment of ailments like cancer, jaundice, cirrhosis, anxiety, and nervous disorders. Scutellaria incana L., commonly known as the Hoary skullcap, is a traditional medicinal plant used by native Americans as a sedative for nervousness or anxiety. S. incana metabolites were identified by comparing their high-performance liquid chromatography (HPLC) retention times and mass spectra with those of the corresponding authentic standards. Where standards were unavailable, the structures were characterized on the basis of their tandem mass spectrometry (MS/MS) spectra following collision-induced dissociation (CID) and the accurate masses of the corresponding deprotonated molecules [M-H] (mass accuracy ± 5 ppm). A total of 40 flavonoids, including two phenolic glycosides, were identified from leaves, stems, and roots of S. incana. Differences in the flavonoid composition between leaves, stems, and roots in S. incana were observed although the flavonoid profile of S. incana is consistent with other Scutellaria species. Further work should focus on assessing the potential of S. incana as a source of these bioactive metabolites.

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A high-performance liquid chromatographic (HPLC) technique coupled with photodiode array (PDA) detection has been proposed for simultaneous determination of five flavonoids, i.e. quercetin 3-O-β-d-glucopyranoside, quercetin 4′-methoxy-3-O-β-d-galactopyranoside, kaempferol 3-O-β-l-rhamnopyranoside, asebotin, and kaempferol 7-methxoy-3-O-α-l-rhamnopyranoside in extract of the whole plant of Saussurea mongolica Franch. The optimum conditions for separation were achieved on a 4.6 × 250 mm i.d., 5-μm particle, C18 column with acetonitrile and 1% acetic acid (20:80, v/v) as the mobile phase at a flow rate of 1.0 mL min−1. For all the analytes, a good linear regression relationship (r of >0.999) was obtained between peak area and concentration over a relatively wide range. The method was validated for repeatability, precision, stability, and accuracy. Seven different extraction procedures were investigated for preparation of the sample solution. The validated method was successfully applied to simultaneous analysis of these flavonoids in S. mongolica and was found to be simple and efficient.

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Summary

Red amaranth (Amaranthus cruentus) and quinoa (Chenopodium quinoa) are pseudocereals with particularly highly regarded nutritional value. Because of the high biological significance of the flavonoids and phenolic acids in these plants, qualitative and quantitative analysis has been performed by HPLC. Extracts from the seeds of two amaranth varieties (A. cruentus v. Rawa and v. Aztek) and quinoa seeds, and their sprouts grown in natural conditions and in the dark were analyzed. The main phenolic acid found both in seeds and sprouts was gallic acid. p-Hydroxybenzoic acid, vanillic acid, p-coumaric acid, caffeic acid, and cinnamic acid were also found in the seeds and p-coumaric acid, syringic acid, and ferulic acid in the sprouts. The main flavonoid found in the sprouts was rutin. Vitexin, isovitexin, and morin were also detected in the sprouts, and orientin, vitexin, isovitexin, morin, and traces of hesperidin and neohesperidin in the seeds. Although sprouting conditions (daylight or darkness) had no effect on gallic acid content, light caused an increase in the amount of rutin and darkness resulted in increased amounts of isovitexin and vitexin.

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Epimedium pubescens Maxim. and Epimedium koreanum Nakai. are two common and confused species of Herba Epimedii in Chinese Pharmacopoeia 2010 edition. Different species and growing conditions lead to chemical differences between the two species which may result in the improper clinical usage. In this work, a new method based on rapid-resolution liquid chromatography combined with time-of-flight mass spectrometry (RRLC/TOFMS) has been developed for identification and differentiation of major flavonoids in two kinds of Epimedium extract and rat plasma. The compounds were identified effectively based on the accurate extract masses and formulae acquired by RRLC/TOFMS. The fragmentation rules deduced by collision-induced dissociation (CID) were successfully implemented in distinguishing some of the isomers, further validating the results. By using the combined analytical techniques, a total of 40 major flavonoids in extracts of two kinds of Epimedium were identified within 30 min, including 31 common components and 9 characteristic components. After oral administration, three prototype compounds in rat plasma were detected by comparing the constituents measured in vitro with those in vivo, and five metabolites were identified by contrasting the fragmentation rules. The identification and structural elucidation of the chemical constituents provided essential data for further pharmacological and clinical studies on different species of Epimedium.

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