trans-Resveratrol and trans-Piceid Content of Hungarian Wines

Plant polyphenols are naturally occurring secondary plant metabolites, synthesized in response to environmental stress factors. As anti-oxidants and free-radical scavengers they serve as essential components of the human diet. Among polyphenols well studied representatives are the trans-resveratrol and trans-piceid molecules, the latter being the glycoside of trans-resveratrol. trans-Resveratrol is known to have anti-inflammatory, anti-tumor, cardio- and vasoprotective effects which help in the prevention of chronic cardiovascular and tumorous diseases.

In the present study, 42 Hungarian wines were analyzed using LC-DAD detection. The wines were from Villány and Eger wine regions representing three wineries from 2003 to 2007 vintage years. The trans-resveratrol amount in the processed wines ranged from 0.75 to 10.4 mg mL⁻¹ and for trans-piceid from 0.1 to 3.7 mg mL⁻¹.

     

Analysis of trans-Resveratrol in Iranian Grape Cultivars by LC

In this study, trans-resveratrol levels were determined in 147 Iranian grape cultivars using a modified extraction and gradient HPLC procedure with photodiode array detection. It was found that 41 out of 147 cultivars contained significant levels of trans-resveratrol. The detected amounts ranged from 0.98 to 6.25 mg kg⁻¹ fresh weight with a mean value of 3.59 (white grapes) and 3.08 mg kg⁻¹ (red grapes), respectively.

     

Sensitized synchronous fluorimetric determination of trans-resveratrol and trans-piceid in red wine based on their immobilization on nylon membranes

It has been carried out the determination of trans-resveratrol and trans-piceid in red wine samples by using room temperature synchronous fluorescence, sensitized through their retention on nylon membranes, in front-face mode. These compounds are weakly fluorescent in solution but their retention allows using the native fluorescence of these compounds as analytical signal, due to the increase in the medium rigidity. To determine these compounds in red wine, a previous liquid-liquid extraction is necessary and in the case of trans-resveratrol it is also necessary a previous cleanup stage using C18 cartridges. Diethylether and ethyl acetate are the selected extractant solvents for trans-resvertarol and trans-piceid, respectively. The retention on nylon membranes was carried out by immersion of the membranes in solutions of these compounds. Variables involved in the retention and measurement processes were optimized, and the analytical figures of merit were obtained under optimal conditions. Ethanol:water 10:90 v:v and ethyl acetate were the solvents used for the retention of trans-resveratrol and trans-piceid, respectively and, for each case a immersion time of 300 and 600 s was selected. Satisfactory linear relation between fluorescence intensity and concentration was found in the intervals 0.040 and 0.242 mg L⁻¹ of trans-resvertarol and 0.009 and 0.288 mg L⁻¹ of trans-piceid. Concentration of 1.08 ± 0.21 mg L⁻¹ for trans-resveratrol and 1.49 ± 0.36 mg L⁻¹ for trans-piceid were found in a wine sample obtained from a pool of commercial red wines.     

Mixed-mode solid-phase extraction followed by acetylation and gas chromatography mass spectrometry for the reliable determination of trans-resveratrol in wine samples

This work presents an advantageous analytical procedure for the accurate determination of free trans-resveratrol in red and white wines. The proposed method involves solid-phase extraction (SPE), acetylation of the analyte in aqueous media and further determination by gas chromatography (GC) with mass spectrometry detection (MS). The use of a mixed-mode SPE sorbent provides an improvement in the selectivity of the extraction step; moreover, the presence of several intense ions in the electron impact mass spectra of its acetyl derivative guarantees the unambiguous identification of trans-resveratrol. Considering a sample intake of 10 mL, the method provides a limit of quantification (LOQ) of 0.8 ng mL⁻¹ and linear responses for concentrations up to 2.5 μg mL⁻¹, referred to wine samples. The average recovery, estimated with samples fortified at different concentrations in the above range, was 99.6% and the inter-day precision stayed below 8%. Trans-resveratrol levels in the analyzed wines varied from 3.4 to 1810 ng mL⁻¹. Cis-resveratrol was also found in all samples. In most cases, equal or higher responses were measured for this latter form than for the trans-isomer. The reduced form of resveratrol, dihydro-resveratrol, was systematically identified in red wines.     

Verification of the selectivity of a liquid chromatography method for determination of stilbenes and flavonols in red wines by mass spectrometry

Quantification of bioactive phenols, like stilbenes and flavonols (SaF), has been conducted to evaluate the nutraceutical potential of red wines. However, there is still a lack of full validated, fast and accessible liquid chromatography methods offering high selectivity and a simple procedure. We present here the use of a high-resolution mass spectrometer to evaluate the selectivity of a feasible and traditional liquid chromatography technique (HPLC–DAD) to analyze markers of aglycone SaF in red wines. The SaF compounds were tested: trans-resveratrol, trans-ε-viniferin, quercetin, myricetin, and kaempferol, as well as trans-cinnamic acid, one of their precursors. System suitability and validation tests were employed for the selected conditions (octylsilane column, methanol mobile phase, and gradient elution). The validation process ensured the HPLC–DAD method was selective, linear, sensitive, precise, accurate and robust. The method was then applied to red wine samples from the Campanha Gaúcha region, Southern Brazil. The real samples contained different SaF levels, showing that the method is applicable to routine use. Furthermore, this was the first SaF characterization of red wines from the Campanha Gaúcha, contributing to regional and product development.     

Analysis of trans-Resveratrol in Iranian Grape Cultivars by LC

In this study, trans-resveratrol levels were determined in 147 Iranian grape cultivars using a modified extraction and gradient HPLC procedure with photodiode array detection. It was found that 41 out of 147 cultivars contained significant levels of trans-resveratrol. The detected amounts ranged from 0.98 to 6.25 mg kg^?1 fresh weight with a mean value of 3.59 (white grapes) and 3.08 mg kg^?1 (red grapes), respectively.     

Simultaneous Determination of Phenolic Compounds in Red Wines by HPLC‐UV

Abstract

Ten samples of commercially Italian red wines were analyzed in order to determine the phenolic content. Variations in wine types are largely due to differences in concentration and composition of these compounds. Polyphenolic compounds are a large and complex group of substances which constitute one of the most important quality parameters of wine. These constituents of red wine contribute to organoleptic characteristics and to antioxidant and anti‐inflammatory properties. Moderate wine consumption is associated with several beneficial physiological effects, which include anticancer activities, inhibition of platelet aggregation, and inhibition of LDL oxidation which constitutes the initial stage of the pathogenesis of arteriosclerosis.

For the analysis, reversed‐phase high performance liquid chromatography (HPLC) method coupled with UV‐Vis detection was used. The method uses a gradient elution to identify nine biologically active phenolic constituents: catechin; epicatechin; trans‐ and cis‐resveratrol; gallic, chlorogenic and caffeic acid; rutin and quercetin in red wine samples. The samples are injected directly without any pretreatment. The method is simple, fast, not expensive and shows good linearity for all constituents, and the detection limits ranged from 0.3–1.6 µg/ml for trans‐resveratrol and gallic acid, respectively. Moreover, the samples were analyzed in different times for estimation of stability of these compounds.     

An insight into chemical composition and bioactivity of 'Prokupac' red wine

Abstract

Autochthonous variety 'Prokupac' (Vitis vinifera L.) red wines with the addition of selected aromatic herbs (Artemisia absinthium, Cinnamomum zeylanicum, Glycyrrhiza glabra and Pimpinella anisum L.) were evaluated for chemical composition and biological activity. Furthermore, their polyphenolic profiles were determined by HPLC-DAD. While total phenolic (TPC) and flavonoid (TFC) contents, along with antioxidant activity, were significantly higher in all examined wine samples, the content of total anthocyanins was decreased, compared to a pure 'Prokupac' wine, used as the control one. On the other hand, 'Prokupac' wines with the addition of cinnamon (S. zeylanicum) and wormwood (A. absinthium) displayed highest antioxidant (EC₅₀, 0.021?±?0.001?mg/mL) and antibacterial (Enterococcus faecalis, MIC/MBC 15.63/62.50?μL/mL) activities, respectively. The study showed that 'Prokupac' wine with the addition of cinnamon was significantly enriched both with TPC and TFC, compared to control wine (p?<?0.05), which may contribute to its market potential.     

Determination of trans-resveratrol in Solanum americanum Mill. by HPLC

Solanum americanum Mill. is a plant that belongs to the Solanaceae family, its respective ripe fruit is dark purple. Ripe S. americanum Mill. fruits were submitted to physicochemical characterisation, and their trans-resveratrol contents were quantified by high-performance liquid chromatography. Such determination was executed with fruits at different stages of ripeness and freeze-stored fruits as well. In natura ripe fruit pulp and peel presented average trans-resveratrol amounts of 1.07 and 0.7960 μg per gram of sample, respectively. These amounts are significantly higher when compared to freeze-stored fruit (0.1353 μg of trans-resveratrol per gram of sample) and to other berries. All ripe fruits showed significant amounts of total anthocyanins and total antioxidants. Thus, for the first time, trans-resveratrol has been identified and quantified in S. americanum Mill. fruit samples.     

Determination of resveratrol in wine by photochemically induced second-derivative fluorescence coupled with liquid–liquid extraction

Basic studies on the photochemical behaviour of trans-resveratrol and its photoproduct are reported. Photometrically and fluorimetrically calculated acidity constants of the former were determined. The usefulness of the determination of resveratrol by photochemically induced fluorescence and second-derivative photochemically induced fluorescence was also examined. The very weakly fluorescent trans-resveratrol is converted into a highly fluorescent photoproduct by irradiating hydroethanolic solutions of trans-resveratrol containing 40% v/v of ethanol for 60 s with intense UV radiation. The photoproduct presents excitation and emission maxima centred at 260 nm, and 364 and 382 nm, respectively. Under these conditions, a linear relationship between fluorescence intensity and trans-resveratrol concentration was found between 6.6 and 66 ng mL⁻¹. Optimum conditions for the extraction of trans-resveratrol from an aqueous phase at pH 5.0 with diethylether were a phase ratio (aqueous/organic) of 2, a shaking time of 60 s and a buffer concentration of 0.15 mol L⁻¹. An extraction recovery of 100% was reached under these conditions. The optimized extraction procedure was applied to the analysis of resveratrol in wine samples, employing the amplitude between 356 and 364 nm of the second-derivative photoinduced emission spectrum as analytical signal. It was found that there is not matrix effect and recoveries around 100% were obtained at different fortification levels.     

Study of the Interaction between <Emphasis Type="Italic">Trans</Emphasis>-resveratrol and BSA by the Multi-spectroscopic Method

The interaction of trans-resveratrol and BSA was investigated by means of fluorescence quenching, resonance light scattering, ultraviolet spectroscopy and Fourier Transform Infrared Spectroscopy. Binding of trans-resveratrol to BSA quenches the BSA fluorescence and both static and dynamic quenching occur with complex formation. The apparent binding constants of trans-resveratrol and BSA at 20, 30 and 40?°C are 1.95×10⁶, 1.70×10⁶ and 1.65×10⁶ L?mol^?1, respectively. The binding site values are (1.25±0.02). According to the Förster theory of non-radiation energy transfer, the binding distances between trans-resveratrol and BSA are 3.47, 3.73 and 3.99 nm at 20, 30 and 40?°C, respectively. The negative enthalpy change and positive entropy change indicated that the interaction of trans-resveratrol and BSA was driven mainly by electrostatic forces. The process of binding was spontaneous whereby the Gibbs energy change was negative.     

Determination of stilbene derivatives in Burgundy red wines by ultra-high-pressure liquid chromatography

The polyphenols, for example stilbenes and flavonoids, are an important family of compounds present in grapes and wines. Several studies have shown that stilbenes are antioxidants and cancer-preventing agents. For the first time, eight natural stilbenes (trans-resveratrol, trans-piceid, cis-piceid, trans-astringin, trans-piceatannol, (+)-trans-ε-viniferin, pallidol, and hopeaphenol), isolated and purified from Vitis vinifera, were simultaneously analysed by ultra-high-pressure liquid chromatography coupled with photodiode-array detection. Separation of the stilbenes by UHPLC was optimized with the assistance of “Quality-by-Design” commercial software. Four different reversed-phase columns packed with 1.5–1.7-μm particles were tested and compared for their retention behaviour and separation efficiency. On the basis of the performance characteristics determined, the VisionHT C18 HL column was selected for the stilbenes studied, because resolution of the critical pair was 1.5 with a peak width of 2–4 s. The optimized method resulted in highly repeatable retention times (RSD 0.03–0.07%), peak areas (RSD 3–6%), and linear ranges were between 0.005 and 50 mg L⁻¹ for most of the compounds. All stilbenes, except trans-astringin, trans-piceatannol, and pallidol were identified and quantified in Burgundy red wines at different concentrations after direct injection of the wines.     

Phenolic natural products of the wines obtained from three new Merlot clone candidates

This work aimed to evaluate the total contents of polyphenolics (the Ribereau-Gayon–Maurié procedure), anthocyanins (using pH differential method) and tannins (the Nègre procedure) as well as the content of phenolic acids (using UPLC/MS chromatography), respectively of the wines obtained from three new Merlot clone candidates in the perennial clonal selection. The aforementioned chemical parameters were determined in the samples covering the period 2009–2012. In comparison both with the standard Merlot wine (mother vine) and the wines obtained from other two clone candidates, the Merlot wine of the clone candidate No. 022 was found to have the highest total content of all three examined components 1.89 ± 0.05 g/L (polyphenolics), 185.59 ± 5.00 mg/L (anthocyanins) and 1.11 ± 0.03 g/L (tannins), as well as six phenolic acids including gallic acid (25.49 ± 0.27 mg/L). These findings are in good agreement with the observed trend for the viticultural parameters indicating the clone candidate No. 022 as more promising than mother.     

Influence of Fermentation Method on Phenolics,Antioxidant Capacity,and Volatiles in Blackberry Wines

The influence of the type of fermentation method on phenolics, antioxidant capacity, and volatiles in blackberry wine was studied. Dry blackberry wines made by traditional fermentation (TF) and carbonic maceration fermentation (CMF) were analyzed for total polyphenols, flavanols, flavonoids, anthocyanins, proanthocyanidin, and antioxidant capacity. High-performance liquid chromatography was used for analysis of nonflavonoid phenolics (gallic, benzoic, salicylic, syringic, caffeic, coumaric, and ferulic) and flavonoids (catechin, quercetin, and rutin). Volatiles were detected by gas chromatography-mass spectrometry. The results showed that CMF fermentation afforded higher antioxidant activity and phenolic content, especially individual polyphenolics. The total level of phenolics in the CMF wine was substantially higher than in traditional wines: 2953 mg of gallic acid equivalents (GAE)/L for CMF wine vs. 1647 mg of GAE/L for traditional wine. A total of 53 kinds of volatile compounds were detected. Of these, 35 were detected in traditionally brewed wine and 46 in CMF fermented wine. Thus, CMF wine had a more complement volatile profile. The dominance of fruity and floral odor components derived from ethyl esters of fatty acids resulted in the indistinguishable aroma of TF and CMF wines. But, CMF wine had a more complicated aroma. The present results could complement existing theory on the processing of blackberry wines.     

Determination of Organic Acids in Red Wine and Must on Only One RP-LC-Column Directly After Sample Dilution and Filtration

A new method for simultaneous determination of organic acids in red wine and must by liquid chromatography was studied. The determination of organic acids in wines can be achieved in less than 13 min, preceded only by a simple sample dilution and filtration step. With this method, the chromatographic separation of eight organic acids and interfering peaks present in red wine, required only one reversed phase column (Waters Atlantis dC18 column, 4.6 × 150 mm ID, 5 μm). As mobile phase, isocratic acetonitrile–0.01 mol L^?1 KH₂PO₄ at pH 2.7 5:95 (v/v) at a flow rate of 0.8 mL min^?1 was used. Detection wavelength was set at 210 nm except for ascorbic acid which was detected at 243 nm. Application to red wine and must confirmed good repeatability and showed a wide variation range for concentrations of organic acids.     

Determination by LC of Polyphenols in Italian Red Wine

A reversed-phase liquid chromatographic method, optimised for the separation of trans-, and cis-resveratrol, catechin, epicatechin, quercetin and rutin, is reported. Separation was achieved using a C18 column and a gradient elution with acetonitrile and 5% formic acid aqueous solution. The analyses required an equilibration period of 10 min and a run time of 25 min for completion. Identification was based on retention characteristics and by relative UV spectra, obtained by photodiode array detector and were compared with commercial standards. Analyses were performed without any sample pre-treatment. Detection was carried out by UV–Vis detector at three different wavelengths. The detection limit ranged from 0.16 μgm L⁻¹ (cis-resveratrol) to 1.5 μgm L⁻¹ (+)-catechin. Investigation was extended to quantitative determination of phenol compounds in Italian red wine and to investigate the stability of the six antioxidants.     

Determination of Flavonoids and Resveratrol in Wine by Turbulent-Flow Chromatography-LC-MS

Turbulent-flow chromatography (TFC) on-line coupled to liquid chromatography mass spectrometry (LC-MS) is used to determine flavonoids and resveratrol in different types of wines. A fully automated system was developed in which 10 mL of sample (diluted wine) was passed over a TFC column, after which the retained analytes were separated by reversed-phase LC and detected by negative ion mode atmospheric-pressure chemical ionization (APCI) MS. The method proved to be fast, non-laborious, robust and sensitive. The feasibility of the method was tested on several red, white and rose wines. Quantitation of resveratrol was possible using the standard addition procedure. Red wine showed the highest amount of resveratrol (4 mg L⁻¹), while rose and white wine contained concentrations which were about ten fold lower.

     

Fast Determination of Phenolic Compounds in Brazilian Wines from Vale do São Francisco Region by CE

Six phenolic compounds were separated and determined by capillary zone electrophoresis in red wine from Brazil’s region Vale do São Francisco with total analysis time of 12 min. The limit of detections varied from 1.59 to 2.24 mg L^?1. The relative standard deviations (for n = 6) varied from 0.28 to 3.50 %. The red wine samples analyzed were bought in the local market and the phenolic compound recoveries were in the range of 98–101 %. The concentrations of gallic acid in the samples of wines varied from 16.0 to 42.0 mg L^?1, caffeic acid (3.16–5.18 mg L^?1), syringic acid (5.73–13.0 mg L^?1), kaempferol (2.32–4.33 mg L^?1), quercetin (1.68–4.03 mg L^?1), myricetin (7.52–25.1 mg L^?1). The concentrations found agree with data reported in the literature.     

Chemical composition and antimicrobial activity of essential oils from Acantholippia deserticola,Artemisia proceriformis,Achillea micrantha and Libanotis buchtormensis against phytopathogenic bacteria and fungi

Essential oils from aerial parts of Acantholippia deserticola, Artemisia proceriformis, Achillea micrantha and Libanotis buchtormensis were analysed by GC–MS. The major compounds identified were β-thujone (66.5 ± 0.2%), and trans-sabinyl acetate (12.1 ± 0.2%) in A. deserticola; α-thujone (66.9 ± 0.4%) in A. proceriformis; 1,8-cineole (26.9 ± 0.5%), and camphor (17.7 ± 0.3%) in A. micrantha and cis-β-ocimene (23.3 ± 0.3%), and trans-β-ocimene (18.4 ± 0.2%) in L. buchtormensis. The oils showed a weak antimicrobial effect (MIC₁₀₀ > 1.5 mg/ml) on most phytopathogens tested. A moderate antimicrobial activity (MIC₁₀₀ between 0.5 and 1.5 mg/ml) was displayed by the oils of A. deserticola, A. micrantha and L. buchtormensis on Septoria tritici and by the oil of A. deserticola on Septoria glycine. The antimicrobial activity was associated to the contents of β-thujone, trans-sabinyl acetate and trans-sabinol. Our results indicate that the tested essential oils have little inhibitory potency not suitable for use as plant protection products against the phytopathogens assayed.     

Mesoporous silica SBA-15, a new adsorbent for bioactive polyphenols from red wine

The aim of this paper is to evaluate the ability of the mesoporous silica SBA-15 to adsorb polyphenols from red wine. The mesoporous molecular sieve silica SBA-15 was hydrothermally synthesized in acidic media and characterized by SAXRD, BET, EDX and SEM. The adsorption behavior of mesoporous silica SBA-15 was investigated at 5 °C for 24 h using an adsorbent dose of 8 g SBA-15 L⁻¹ red wine. The total polyphenols content expressed as mg of gallic acid equivalents (GAE L⁻¹) was estimated from the standard curve of gallic acid (absorbance at 280 nm). HPLC chromatograms of methanolic extract from mesoporous SBA-15 at 256, 280, 324, and 365 nm exhibits the strong retention of quercetin and cis-resveratrol and a reasonable retention of trans-resveratrol, catechin, epicatechin, rutin, and phenolic acids (meta- and para-hydroxybenzoic, vanillic, caffeic, syringic, salicylic and para-coumaric acids).