Content Of Flavonol Glycosides Research Articles

Effect of wounding on chalcone synthase and pathogenesis related PR-10 gene expression and content of phenolic compounds in bilberry leaves

The influence of artificial wounding on biosynthesis of flavonoids and hydroxycinnamic acids was studied in bilberry leaves using two separate wounding experiments. In the first experiment bilberry leaves were wounded by cutting. The expression of the first gene from flavonoid pathway, chalcone synthase (CHS) and a wound induced pathogenesis related PR-10 gene was analysed from samples collected immediately and after 3, 6, 24 h and 4 d from the wounding treatment. In the second experiment annual shoots were removed. Proanthocyanidins, flavonol glycosides and hydroxycinnamic acids were quantified in leaf samples after 0-5 d (experiment 1) and 5 weeks (experiment 2) from the treatment. In the first experiment, no change was observed in the expression of CHS whereas increase in expression of PR-10 gene was detected after 6 h of wounding treatment. In both experiments, the contents of flavonol glycosides and hydroxycinnamic acids were not influenced by the wounding treatment and the contents of proanthocyanidins were decreased.

Effects of elevated CO2 and O3 on leaf litter phenolics and subsequent performance of litter-feeding soil macrofauna

Two field-growing silver birch (Betula pendula Roth) clones (clone 4 and 80) were exposed to elevated CO2 and O3 for three growing seasons (1999–2001). The phenolic compounds of naturally abscised leaf litter were analyzed in order to determine the possible CO2- and O3-induced changes in the litter quality. The potential litter-mediated CO2 and O3 effects on litter-feeding soil macrofauna (detritivore) performance were assessed in microcosm experiments, i.e., the relative growth rates (RGR) of Lumbricus terrestris and Porcellio scaber, the relative consumption rates (RCR) of P. scaber, and mortality of the test animals were measured. The leaf litter grown under elevated CO2 had increased concentrations (weight per mass unit) and contents (weight per leaf) of phenolic acids, flavonol glycosides, condensed tannins and total measured phenolics. Elevated O3 increased the concentrations of 3,4’-dihydroxypropiophenone 3-β-d-glucoside (DHPPG) and flavonoid aglycones but only under ambient CO2. However, elevated O3 effects on the content of some low-molecular-weight phenolic (LMWP) compounds (i.e. phenolic acids, DHPPG, flavonoid aglycones) and total LMWP changed over time emphasizing the importance of conducting long-term (>3 years) exposure studies. In general, RGR of young L. terrestris was affected by the litter quality changes induced by elevated CO2 and O3, as the animal growth rates were reduced when they were fed with CO2- and O3-exposed leaf litter of clone 80 in Experiment 1. P. scaber RCR or RGR responses to CO2- and O3-induced changes in litter quality were more variable and inconsistent, and neither were there any litter-mediated CO2 and O3 effects on animal mortality in these microcosm experiments. In conclusion, elevated CO2 has the potential to alter silver birch leaf litter quality, but the possible O3 effects on phenolic compounds and litter-mediated CO2 and O3 effects on detritivores are more difficult to validate.

HPLC-DAD-ESIMS analysis of phenolic compounds in bayberries ( Myrica rubra Sieb. et Zucc.)

Qualitative analysis of the ethyl acetate extracts from three bayberry cultivars, Xiangshan, Biqi and Dongkui, was performed by means of a hyphenated technique of HPLC coupled to photodiode array detection and electrospray ionization mass spectrometry (HPLC-DAD-ESIMS). Three phenolic compounds were identified (gallic acid, protocatechuic acid, and quercetin 3-glucoside) and seven others (two myricetin hexoside and two myricetin deoxyhexoside derivatives; quercetin hexoside and quercetin deoxyhexoside derivatives; kaempferol hexoside derivative) partially identified. Quantification of phenolic compounds was performed by HPLC-DAD, which revealed that gallic acid (2.6–7.0 mg/kg FW) was the major phenolic acid in all analysed cultivars. Myricetin glycosides (71.1 mg/kg FW) were the major flavonol glycosides in cultivar Xiangshan and quercetin glycosides (117.8 mg/kg FW) were the major ones in cultivar Biqi. Cultivar Dongkui had medium contents of quercetin glycosides (48.0 mg/kg FW) and myricetin glycosides (53.2 mg/kg FW). Kaempferol glyosides (3.1–4.6 mg/kg FW) were the lowest contents of flavonol glycosides in the assayed bayberries. These results are relevant not only from a nutritional point of view, but also in the control of color stability and haze formation during bayberry juice processing and storage.

Identification of Flavonoids in Hakmeitau Beans (Vigna sinensis) by High-Performance Liquid Chromatography−Electrospray Mass Spectrometry (LC-ESI/MS)

Liquid chromatography coupled with electrospray mass spectrometry (LC-ESI/MS) with positive and negative ion detection was used for the identification of flavonoids in Hakmeitau beans, a black seed cultivar of cowpea (Vigna sinensis). Gradient elution with water and acetonitrile, both containing 2% formic acid, was employed in chromatographic separation. The peaks were identified by comparison of the retention times and the UV-vis spectroscopic and mass spectrometric data with authentic standards and/or literature data. The identified flavonoids included six anthocyanins (cyanidin 3-O-galactoside, cyanidin 3-O-glucoside, delphinidin 3-O-glucoside, malvidin 3-O-glucoside, peonidin 3-O-glucoside, and petunidin 3-O-glucoside) and four flavonol/flavonol glycosides (kaempferol 3-O-glucoside, quercetin, quercetin 3-O-glucoside, and quercetin 3-O-6' '-acetylglucoside). The tentatively identified flavonoids included two anthocyanins (malvidin 3-O-acetylglucoside and peonidin 3-O-malonylglucoside) and three flavonol glycosides (myricetin-3-O-glucoside, quercetin 7-O-glucoside, and quercetin-3-O-diglucoside). These flavonoids are present in seed coats, and the contents of anthocyanins and flavonol glycosides were 20.7 and 2.0 mg/g, respectively.

BENZOTHIADIAZOLE INDUCES DEFENCE RESPONSES IN BERRY CROPS

Plants have developed multiple protection strategies during evolution in response to invading pathogens and environmental stresses. Flavonoids are a large and diverse group of over 4000 compounds, many of which are known to play an important role against UV-light stress and microbial attacks in plants. Many of these plant defence compounds are also health-promoting phytochemicals in the human diet. Strawberry (Fragaria x ananassa) contains a variety of such phenolic compounds. We found that the most disease resistant (to gray mold) strawberry cultivar contained considerably more flavonoids than the most susceptible one, but the role of these compounds in disease resistance is still unclear. Defence mechanisms in plants can be activated by biotic or abiotic elicitors, which trigger a defence pathway leading to the expression of several defence genes and the accumulation of antifungal compounds, which eventually leads to the inhibition of the fungal growth. We tested the ability of benzothiadiazole (BTH) to induce resistance to powdery mildew (Sphaerotheca macularis) in strawberry. Powdery mildew has become a serious disease in strawberry grown in greenhouses in many parts of the world. As chemical control is difficult because of the rapid development of fungicide-insensitive strains, alternative strategies are needed. We showed that foliar applications of BTH (0,6-1,2 g/l) on young strawberry leaves provide effective mildew control in greenhouses. The flavonol glycoside content of BTH-treated leaves was also analyzed by HPLC and ESI-MS method, but no clear differences were detected between BTH-treated and control plants. However, the levels of two flavonols, quercetin and kaempferol, in berries were increased in response to foliar treatments under field conditions. The results suggest that BTH and related bioactivators may become a realistic alternative for chemical control against powdery mildew in strawberries grown in greenhouses and plastie tunnels.

Phenolic compounds in berries of black, red, green, and white currants (Ribes sp.).

Multiple health benefits associated with phenolic compounds have raised the interest in the contents of these plant metabolites in foods. Several phenolic compounds were quantified from berries of Ribes nigrum (black and green currants) and Ribes x pallidum (red and white currants), by using sequential extraction with ethyl acetate and methanol and an optimized reversed-phase HPLC method with diode array detection. The highest contents of anthocyanins (3,011 mg/kg fresh weight, expressed as the aglycon) and flavonol glycosides (100 mg/kg) were found in black currant. The lack of anthocyanins in the colorless (green, white) berries was associated with increased levels of phenolic acids, especially p-coumaric acid (80 mg/kg in green currant vs. 45 mg/kg in black currant) and 4-hydroxybenzoic acid (18 mg/kg in white currant vs. 3 mg/kg in red currant). Previously, proanthocyanidins have not been quantified from berries. This study showed that the contents of extractable (22-41 mg/kg) and nonextractable proanthocyanidins (32-108 mg/kg) are comparable to those of other phenolics, with the exception of anthocyanins in black currant. Our results suggest that anthocyanins dominate in black and red currants, whereas proanthocyanidins and phenolic acids are the predominant phenolic compounds in green and white currants.

Patterns in content of phenolic compounds in leaves of mountain birches along a strong pollution gradient

The contents of individual low-molecular weight phenolic compounds (LMWPs) in mountain birch, Betula pubescens ssp. czerepanovii, leaves collected during 1996–1998 in six plots 7–65 km south of the nickel–copper smelter at Monchegorsk, Kola Peninsula, NW Russia, were reported. A high-performance liquid chromatography–electrospray ionisation–mass spectrometry (HPLC–ESI–MS) was used for the rapid identification of low-molecular weight phenolics. Quantification was performed by the analytical high-performance liquid chromatography with UV-detection. Contents of (+)-catechin and some gallic acid derivatives decreased significantly, and contents of flavonol glycosides slightly increased with the distance from the smelter. Hydroxycinnamic acid derivatives remained unaffected. These changes in birch leaf phenolics are probably related to the effect of environmental contamination on the biosynthetic reactions both in the shikimate and phenylpropanoid pathways.

Hippuric acid as a major excretion product associated with black tea consumption

1. Nine habitual tea-drinking volunteers were recruited and asked to follow a low-polyphenol and low-caffeine diet for 6 days and to provide daily 24-h urine samples. On day 4 of the experiment strong black tea brewed under standardized conditions was reintroduced to the volunteers' diet. 2. 1H-NMR and HPLC profiling of the urine samples indicated that consumption of black tea (6-10 mugs per day) was associated with a significant (p=0.00017) increase in hippuric acid excretion relative to control, increasing from 153-512 to 742-1374 mg day-1. The excretion of substantial amounts of hippuric acid has not previously been associated with black tea consumption. 3. For some volunteers, the quantity of benzoic acid processed exceeded the acceptable daily intake (ADI), but this is not considered to constitute any hazard. 4. A mass-balance analysis indicated that the necessary quantity of benzoic acid could not be obtained from the contents of gallic acid, flavanols, flavonol glycosides and theaflavins in black tea even if 100% transformation was obtained, suggesting that the thearubigins (the major and chemically ill-defined polyphenols of black tea) may be an important source.

Composition and Content of Flavonol Glycosides in Green Beans and Their Fate during Processing

Four varieties of green bean (Phaseolus vulgaris) were analyzed for flavonol composition and content. Two flavonol conjugates, not previously reported in green bean, were found in three of the varieties. These are quercetin 3-O-(2G-β-d-xylopyranosylrutinoside) (1), (1.0−2.0 μg/g of fresh weight) and the corresponding kaempferol analogue (2) (0.3−0.7 μg/g). The major flavonol component in all of the varieties was quercetin 3-O-glucuronopyranoside (3) (3.5−15.1 μg/g) with lesser amounts of quercetin 3-O-rutinoside (4) (0.2−4.3 μg/g) and kaempferol 3-O-glucuronopyranoside (5) (0.5−1.3 μg/g). Kaempferol rutinoside (6) was detected in only one variety (0.8 μg/g). Commercial processing, such as canning, did not result in chemical breakdown of the conjugates, although between 8.8 and 24.4%, depending on the conjugate, was leached into the cooking water. Keywords: Phaseolus; green bean; HPLC; flavonol; glycoside

Composition and content of flavonol glycosides in broccoli florets (Brassica olearacea) and their fate during cooking

The two main flavonol glycosides present in broccoli florets were identified as quercetin 3-O-sophoroside and kaempferol 3-O-sophoroside. Three minor glucosides of quercetin and kaempferol were also detected, namely isoquercitrin, kaempferol 3-O-glucoside and a kaempferol diglucoside. The sophorosides of quercetin and kaempferol were present in raw florets at a level of 65 mg kg−1 and 166 mg kg−1 fresh weight, respectively. The total content of quercetin and kaempferol glycosides expressed as aglycone was 43 and 94 μg g−1 fresh weight, respectively, and these agree with other recently published data. During the cooking process only 14–28% of the individual glucosides were retained in the cooked tissue, the remainder being largely leached into the cooking water with only a small loss attributed to the formation of the respective aglycones. © 1998 SCI.

Composition and content of flavonol glycosides in broccoli florets (Brassica olearacea) and their fate during cooking

Composition and content of flavonol glycosides in broccoli florets (Brassica olearacea) and their fate during cooking

Flavonol Glycoside Content and Composition of Tea Infusions Made from Commercially Available Teas and Tea Products

The composition and content of flavonol glycosides (FGs) have been measured in infusions of a range of black tea and black tea products. Tea contains a mixture of glycosides of quercetin, kaempferol, and myricetin and the total level of these glycosides, in infusions prepared in a normal domestic manner, for the leaf teas varied from 36.5 to 88.3 mg/L, although greater variation was observed for the tea products, from 7.0 to 428.1 mg/L. Altogether seven quercetin, five kaempferol, and two myricetin glycosides were detected; their relative amounts varied significantly in the different samples. The significance of these differences in relation to the bioavailability and potential bioactivity of these compounds is discussed. Keywords: Tea; flavonol; glycoside; HPLC; quercetin; kaempferol; myricetin

The analysis by HPLC of green, black and Pu'er teas produced in Yunnan

AbstractSamples of tea (Quingmao, steamed, black and Pu'er) produced in Yunnan Province, People's Republic of China, from the locally characteristic large‐leaved Camellia sinensis, have been brewed and the brews analysed for their contents of flavonol glycosides, flavan‐3‐ols and their oxidation products. Several samples of Pu'er tea manufactured in the 1920s, 1930s and 1940s were also examined. The brews prepared from Quingmao tea and steamed green tea leaf were very similar containing primarily flavan‐3‐ols accompanied by flavonol glycosides, theogallin and gallic acid. The profile of flavanols was unusual, being dominated by (−)‐epicatechingallate (rather than (−)‐epigallocatechingallate) and by an unusually large (+)‐catechin content. The brew of the equivalent black tea retained significant amounts of residual flavanols (particularly (−)‐epicatechingallate and (+)‐catechin), and contained significant amounts of thearubigins, theaflavic acids and theaflavins (including the less common analogues probably derived from the oxidation of (+)‐catechin). The brews prepared from the Puer teas were distinguishable from the black tea brew by the absence of theaflavins and theaflavic acids, and by much smaller residues of flavanois and flavonol glycosides. The contents of thearubigins varied considerably whereas those of gallic acid were similar.

Ozone tolerance related to flavonol glycoside genes in soybean

Ozone toxicity can reduce soybean yields by an estimated 5 to 20%. The most economical and prachcal solution to the problem would be to use ozone-tolerant cultivars. Because ozone toxicity is an oxidative stress, one would expect that plants having higher concentrations and proper kinds of antioxidants would be more tolerant. To test this hypothesis, 20 soybean lines or cultivars varying in contents of flavonol glycosides (naturally occurring antioxidants) were tested for ozone tolerance in a fumigation chamber and in phyto-toxic concentrations of ozone in ambient, unfiltered, air in a greenhouse. In general, ozone tolerance was associated with the presence of kaempferol glycosides, particularly K3 through K6 and K9. Lines containing no kaempferol glycosides (OX942 & OX281) were among the most sensitive to ozone stress. The K9 compound has been associated with reduced numbers of stomata, drought tolerance, and slower growth rates, and this could reduce ozone absorption and toxicity, or K9 may be more effective in detoxifying ozone than other glycosides. Lee soybean was more tolerant to ozone and to manganese (Mn) toxicity (also an oxidative stress) than Forrest. Cross tolerances of plant genotypes to these two stresses deserve additional study. Among cultivars compared, Mukden was ozone tolerant, Columbia and Harosoy were sensitive, and Blackhawk was moderately sensitive

Flavonol glycosides production in cell suspension cultures of Vancouveria hexandra

Cell suspension cultures of Vancouveria hexandra produced a large amount of des- O-methylanhydroicaritin glycosides (epimedosides A, E, hexandraside E, ikarisoside C and an unidentified triglycoside) in addition to a small amount of anhydroicaritin glycosides (epimedin B, hexandraside A, icariin, anhydroicaritin-3- O-fucosylrhamnoside 7- O-glucoside and anhydroicaritin-3- O-glucoside 7- O-glucoside). These cells also produced large amounts of kaempferol glycosides (kaempferol-3- O-glucosylrhamnoside 7- O-rhamnoside, kaempferitrin and afzelin) which do not occur in the original plant. The production of flavonol glycosides was influenced by nutrients such as sucrose, nitrogen and phosphate. Higher phosphate increased contents of 8-isoprenylated flavonol glycosides, but had practically no effect on that of kaempferol glycosides. This cell culture required 2,4-dichlorophenoxyacetic acid for the production of flavonol glycosides. At 100 μM 2,4-D, anhydroicaritin glycoside content increased up to 4.5 mg 20 ml −1 medium (1.8% dry wt), while the concentrations of the other flavonol glycosides were not affected.

Studies on Epimedium Species: Flavonol glycosides and isozymes

Flavonol glycosides, icariin, epimedin B and C, contained in six Epimedium species were qualitatively and quantitatively analysed by HPLC. Significant differences in the flavonol glycoside content were found between species. The highest accumulation of flavonol glycoside occurred about two months after germination. p]Electrophoretic analyses of isozymes, phosphoglucomutase, phosphoglucose isomerase, glutamate oxaloacetate transaminase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase and glutamate dehydrogenase, were performed. E. diphyllum and E. sagittatum can be distinguished from other species. It is evident from this analysis that E. setosum and E. grandiflorum var. higoense are closely related to E. diphyllum, E. sempervirens and E. grandiflorum. These results show that the electrophoretic analysis of isozymes supports the morphological classification of Epimedium species in Japan.

Flavonol glycosides of different species and hybrids from the Prunus section eucerasus and the growth-promoting activity of quercetin derivatives

The total content of flavonol glycosides was lowest in P. avium L., medium in P. cerasus L. and highest in P. fruticosa Pall. The hybrids between P. fruticosa × P. avium and P. cerasus × P. fruticosa showed an intermediate pattern. Quercetin glucoside and quercetin rhamnoglucoside rutin) occurred regularly in all trees investigated. Some flavonol glycosides could not be identified exactly. Young shoot segments of P. avium (F12/1) were grown for 4 weeks in vitro in continuous darkness or at a day length of 16 hours. The basal medium was supplemented with several flavonoids. Rutin and dihydroquercetin stimulated the callus growth. The tissue was unresponsive to quercetin and kaempferol. Among the factors contributing to the callus production were the light regime as well as the growth factors of the medium.

Flavonol Glycoside Genes and Photosynthesis in Soybeans

Soybean [Glycine max (L.) Merr.] cultivars and strains vary in leaf content of flavonol glycosides which are controlled by the nonallelic genes Fg1, Fg2, Fg3, Fg4, T, and Wm. This study was undertaken to see if certain combinations of these genes or their products were associated with alterations in photosynthetic activity of the leaves.Chlorophyll concentration, specific leaf weight (SLW), and photosynthetic rate (P) were measured in field‐grown soybean plants differing in flavonol glycoside genes. Similar measurements were made in the growth chamber in an Fg2 population segregating for Fg1/fg1 and for T/t.The Fg1fg2Fg3t genotype had high concentrations of kaempferol 2G‐glucosylgentiobioside (K9) in the leaves, and low levels of chlorophyll, P, and SLW. In the presence of Fg2 instead of fg2, or of T instead of t, the level of K9 was reduced and chlorophyll concentration, P, and SLW were increased. The recessive wm gene was associated with very low levels of flavonol glycosides in the leaves, and this also appeared to reduce P, but not chlorophyll nor SLW.Bean yield and P were highly correlated. Cultivar surveys indicate that there has been a tendency in breeding programs either to eliminate Fg1 while maintaining Fg3 at a high frequency, or to reduce the frequencies of both Fg1 and Fg3. In the future, soybean breeders could eliminate some crosses which would produce a high proportion of low yielding material by avoiding parents which result in complementary gene action of Fg1 and Fg3.