Quercetin in red wine

The amounts of analytes are compiled in Table 2.74. The results indicated that the concentration of polyphenols in red wines depends on both the grape variety and on the exogenous factors. The validation parameters of the method were good, the recoveries were in each case over 98 per cent, the coefficients of variation were between 1.3 per cent and 4.3 per cent, and the limit of detection ranged from 10/rg/l to 0.1mg/l. It was stated that the method is suitable for the determination of silbene compounds and quercetin in red wines [194],... 

Molinelli, A. Weiss, R. Mizaikoff, B., Advanced solid phase extraction using molecularly imprinted polymers for the determination of quercetin in red wine, J. Agric. Food Chem. 

SE is normally followed by SPE to remove possible interferences and to increase the concentration or purify the analyte [49]. The presence of acid in the extraction solvent helps to prevent ionization of the flavonoids and hence to reduce their retention. In more complex studies, two-dimensional SPE (2D-SPE) can be applied for the extraction step [50]. Recently, molecular imprinted polymers (MIPs) have attracted attention for the SPE of flavonoids in food matrices [51], as in the determination of quercetin in red wines [52,53], myricetin in fruit samples [54], or a mixture of quercetin myricetin and amento-flavone from different plant extracts [55] however the use of MIPs is limited because a specific MIP has to be designed for each target compound. 

Another RP-HPLC method was applied for the determination of gallic acid, trans-veratrol, quercetin and rutin in red wines. Samples of wines were filtered and injected into... 

To investigate the probable health benefits of flavonoids and stilbenes in red wine, a RP HPLC method with enhanced separation efficiency, selectivity, sensitivity, and speed has been established for the determination of the flavonols quercetin, myricetin, and kaempferol and the stilbenes cis- and trany-resveratrol in a single The... 

Careri, M., C. Corradini, L. Elviri, 1. Nicoletti, and 1. Zagnoni. (2003). Direct HPLC Analysis of Quercetin and trans-Resveratrol in Red Wine, Grape, and Winemaking Byproducts, /, Agric, Food Chem. 51, (18), 5226-5231. 

Table 13.11. Phamacokinetic values for catechin metabolites in red wine and quercetin...

Phenolic compounds, primarily flavonoids, have antioxidant properties which may contribute to health benefits of wine consumption (Kanner et ai, 1994 Frankel, 1994). Wine consumption has a possible cardioprotective effect and may prevent thrombosis (Frankel, 1994). Epicatechin and quercetin are more effective in preventing LDL (low density lipoprotein) oxidation than a-tocopherol (vitamin E) (Frankel, 1994). Quercetin is found at an average concentration of 25 mg/L in red wine. Catechin and epicatechins are among the most abundant phenolics in wine and are present at about 150 mg/ L in red wine and about 15 mg/ L in white wine. Resveratrol is thought to be of major importance as a dietary antioxidant in red wines, but levels are much lower than catechin/epicatechin (Frankel, 1994). 

Moreover, numerous studies have been developed on CHD patients. The intake of red grape polyphenol extract - which contains epicatechin, catechin, gallic acid, trans-resveratrol, s-viniferin, rutin, quercetin, p-coumaric, and ferulic acid -improved the endotheUal function in CHD patients. Similar results have been foimd for red grape juice [123]. Hypercholesterolemic patients were asked to consume red grape juice (500 mL/day) and red wine (250 mL/day) for 14 days. Results showed increased brachial artery flow-mediated dilation in both cases. However, increased endothelium-independent vasodilation was observed only in red wine-drinking patients [124]. Similar results and the same conclusions were drawn from a similar study on red grape juice. The daily ingestion of moderate... 

Phenolic substances in red wine were shown to inhibit LDL oxidation in vitro [95]. In previous studies, red wine-derived phenolic acids [115,116], resveratrol [117], flavonols (quercetin, myricetin) [68,118,119], catechins [66,120], and the grape extract itself [121,122] have been shown to possess antioxidant properties. The finding that ethanol and wine stripped of phenols did not affect LDL oxidation further confirmed that the active antioxidant components in red wine are phenolic compounds [123]. Red wine fractionation revealed major antioxidative potency to monomeric catechins, procyanidins, monomeric anthocyanidins, and phenolic acids [123]. The flavonol quercetin and the flavonol catechin were both tested for antioxidative and antiatherogenic effects in the atherosclerotic E° mice [111]. E° mice at the age of 4 weeks were supplemented for up to 6 weeks in their drinking water with placebo (1.1% alcohol) or with catechin or quercetin (50 pg/day/mouse). The atherosclerotic lesion area was smaller by 39% or by 46%, respectively, in the treated mice than in E° mice that were treated with placebo (Fig. 4A-E). 

Figure 4 Consumption of red wine or its poiyphenois catechin and quercetin by E° mice decreases the deveiopment of atheroscierotic iesions, inhibits oxidation of LDL, and increases serum paraoxonase activity. (A-E) The aortic arch from E° mice that consumed piacebo, catechin, quercetin, or red wine was anaiyzed. Resuits are expressed as the mean of the iesion area in square micrometers + SD. p< 0.05 (vs. piacebo). (F) LDL was isoiated from E° mice that consumed piacebo, red wine (0.5 mL/day per mouse), catechin or quercetin (50 pg/day per mouse) for a period of 6 weeks. LDL (100 pg of protein/mL) oxidative state (basai, not induced oxidation) was determined as iipid peroxide ieveis. Resuits are expressed as mean + S.D. (n = 3), p < 0.01 (vs. piacebo). (G) Paraoxanase activity was measured as aryiesterase activity in serum derived from E° mice that consumed piacebo, catechin, quercetin, or red wine for 6 weeks. Resuits are expressed as mean + S.D. of three separate determinations. p < 0.01 vs. piacebo. LDL, iow-density iipoprotein.

Qne study investigated the bioavailability of quercetin after consumption of red wine compared with eonsumption of either onions or tea over 3 days [20]. At the time the blood samples were taken, the plasma concentration after red wine consumption was between those observed after consumption of onions and tea. However, there was no difference in the 24-h urinary excretion after consumption of quercetin from red wine and onions (although for tea excretion... 

HAYEK T, FURHMAN B, VAYA J, ROSENBLAT M, BELINRY P, COLEMAN R, ELIS A, AVIRAM M (1997) Reduced progression of atherosclerosis in apolipoprotein E-deficient mice following consiunption of red wine, or its polyphenols quercetin or catechin, is associated with reduced susceptibility of LDL to oxidation aggregation, Arteriosclerosis, Thrombosis and Vascular Biology, 17, 2744-52. 

Red wine contains quercetin, rutin, catechin, and epicatechin, among other flavonoids (Frankel and others 1993). Quercetin and other phenolic compounds isolated from wines were found to be more effective than a-tocopherol in inhibiting copper-catalyzed LDL oxidation. It has been determined that quercetin has also several anti-inflammatory effects it inhibits inflammatory cytokine production (Boots and others 2008), inducible NO synthase expression and activation of inflammatory transcription factors (Hamalainen and others 2007), and activity of cyclooxygenase and lipooxygenase (Issa 2006), among others. 

People in France eat a lot of fatty foods but suffer less from fatal heart strokes than people in the northern regions of Europe or in North America, where wine is not consumed on a regular basis ( French paradox ). There is an increased favorable effect from red wine. The unique cardioprotective properties of red wine are due to the action of flavonoids, which are minimal in white wine. The best-researched flavonoids are resveratrol and quercetin, which confer antioxidant properties more potent than a-tocopherol. 

A new poly(7-oxobomene-5,6-dicarboxylic acid-Wod -norbomene)-coa(cd silica has been synthesized and applied for the separation of flavonoids in model systems and in the extracts of onion, elder flower blossom, lime blossom, St. John s Wort and red wine. Separation was performed in a (150 X 4 mm i.d. particle size 7 /rm) column at room temperature. Flavonoids (quercitrin, myricetin, quercetin, kaempferol and acacetin) were separated with gradient elution water-ACN (20 mmol TFA) from 78 22 to 70 30 v/v in 3min. The flow rate was 2 ml/min. The separation of the standard mixture is shown in Fig. 2.51. It has been stated that the method is rapid, accurate and the MS detection makes possible the reliable identification of flavonoids [153],... 

Another study employed a similar RP-HPLC method for the determination of trails- and d.v-rcsvcratrol, catechin, epicatechin, quercetin and rutin in wines and musts. Wine samples were filtered and diluted when necessary and used for analysis without any other pretreatment. Separation was performed in an ODS column (150 X 4 mm i.d. paricle size 5 71m) at ambient temperature. The gradient began with ACN-5 per cent aqueous acetic acid (9 91, v/v) for 0-10 min to 25 75 in 1 min hold for 11 min to 70 30 in 1 min, hold for 5 min. The flow rate was 1 ml/min. Analytes were detected by DAD. Fluorescence detection used 280/315 nm (excitation/emission) for catechin and epicatechin 314/370 nm for fims-resveratrol and 260/370 nm for d.v-rcsvcratrol. Chromatograms of a red wine sample obtained at different... 

The flavonoid content of plant foods may be affected by growing conditions.For example, red wine produced in the warm, dry, and sunny conditions prevalent in the New World tend to contain more quercetin and myricetin (but less catechin) than the wines produced in the cooler and damper regions of Northern Europe.Similar regional and climatic effects on... 

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