白藜芦醇在银电极上的吸附伏安行为及其应用

白藜芦醇(3,5,4-三羟基芪)通常存在于葡萄、桑椹等多种植物中, 葡萄酒中也有一定的含量[1]. 由于白藜芦醇对防治癌症、动脉硬化和冠心病等疾病有较好的疗效[1,2], 近年来对白藜芦醇生物活性的研究日益受到重视. 白藜芦醇的测定一般采用高效液相色谱和毛细管电泳等方法[3～5], 这些方法均需对样品进行减压浓缩和萃取等处理, 比较繁琐. 本文对白藜芦醇在银电极上的吸附伏安行为进行了研究, 并将其应用于葡萄酒中白藜芦醇含量的直接测定, 获得了较好的实验结果.     

葡萄酒中白藜芦醇的固相萃取GC/MS法测定及其生理活性的初步研究

用反向C₁₈固相萃取小柱对葡萄酒进行了预处理,然后用BSTFA硅烷化试剂对萃取物进行了衍生化处理,用气相色谱/质谱对葡萄酒中顺式、反式白藜芦醇进行了同时测定,建立了定量分析方法.对方法的精密度和回收率进行了测定,方法的相对标准偏差分别为4.48%(顺式)和5.23%(反式).顺式、反式白藜芦醇的平均回收率分别为94.4%和97.6%.并对10种国产葡萄酒和两种进口葡萄酒样品进行了测定.对白藜芦醇的生理活性也进行了实验,初步探讨了白藜芦醇对大鼠血管平滑肌细胞(VSMC)、大肠癌细胞株Lovo细胞和小鼠成纤维株3T3细胞的生长生殖活性的影响,观察了其形态变化.     

葡萄酒中顺反式白藜芦醇异构体的反相高效液相色谱法测定

建立了一种同时检测葡萄酒中功能成分白藜芦醇及其糖苷的4种异构体含量的RP -HPLC方法。通过紫外照射促使白藜芦醇及其糖苷的反式异构体转化 ,以获得顺式异构体标准样品 ,以葡萄酒直接进样方式及水 -乙腈二元梯度洗脱同时测定葡萄酒中白藜芦醇4种异构体含量。4种异构体回收率在92.4%～98.6%之间 ,相对标准偏差在3.06%～5.42%之间。采用本方法测定国产“龙徽”干红葡萄酒中白藜芦醇总量达到6.64mg·L -1,其中80 %以上为反式异构体成分。葡萄酒开启4h和8h后白藜芦醇总量分别减少了18%和38 %,其中反式白藜芦醇糖苷的损失尤为严重。本实验建立的RP -HPLC方法能够简便、有效地检测葡萄酒中4种白藜芦醇异构体含量     

固相萃取-高效液相色谱法测定葡萄酒中白藜芦醇及其糖苷异构体

建立了固相萃取-高效液相色谱(SPE-HPLC)测定葡萄酒中白藜芦醇及其糖苷异构体的方法,并用此方法测定了市售的15种葡萄酒中顺反式白藜芦醇及其糖苷的含量。实验确定了葡萄酒样品中的白藜芦醇及其糖苷的固相萃取方法,通过优化萃取条件,有效地去除了葡萄酒中大量干扰成分。采用Hypersil C18柱(4.6 mm i.d.×250 mm,5μm)分离,以乙腈-水为流动相,线性梯度洗脱,用二极管阵列检测器分别于288 nm和306 nm波长下检测,4种组分分离良好,提高了分析结果的准确性。采用外标法定量,4种组分的质量浓度与其峰面积在一定的范围内有良好的线性关系,相关系数为0.9973～0.9999。4种组分的平均加标回收率为97.4%～98.8%(相对标准偏差为2.1%~3.2%),检测限为0.002~0.005 mg/L。对市售15种葡萄酒的检测结果表明,白藜芦醇作为葡萄酒中重要的生物活性成分,其含量与葡萄酒的酿造方式、葡萄品种、葡萄产地有密切的关系。该方法还可用于其他天然产物中白藜芦醇及其糖苷异构体的测定。     

高效液相色谱法测定进口葡萄酒中的白藜芦醇及其甙

采用高效液相色谱法测定进口葡萄酒中的白藜芦醇及其甙。葡萄酒样品经过C18固相萃取柱净化后,采用Agilent Eclipse XDB-C18色谱柱进行分离,以乙腈溶液为流动相进行梯度洗脱,采用光电二极管阵列检测器在288nm和306nm处进行检测。白藜芦醇及其甙的质量浓度在0.2~20mg·L-1范围内与其峰面积呈线性关系,反式白藜芦醇甙、反式白藜芦醇、顺式白藜芦醇甙和顺式白藜芦醇的测定下限分别为2.6,1.5,4.6,3.0ng。加标回收率在77.3%~104%之间,测定值的相对标准偏差在1.4%~8.3%之间。     

葡萄酒中白藜芦醇的固相萃取GC／MS法测定及其生理活性？…

用反向Ｃ１８固相萃取小柱对葡萄酒进行了预处理，然后用ＢＳＴＦＡ硅烷化试剂对萃取物进行了衍生化处理，用气相色谱／质谱对葡萄酒中顺式、反式白藜芦醇进行了同时测定，建立了定量分析方法。     

流动注射化学发光法测定白藜芦醇苷

基于白藜芦醇苷对Luminol KIO4 H2O2体系化学发光的抑制作用,建立了一种快速测定白藜芦醇苷的流动注射化学发光分析法。测定白藜芦醇苷的线性范围为2.0×10-8～8.8×10-6mol L;检出限为6.7×10-9mol L;相对标准偏差为1.9%(c白藜芦醇苷=4.4×10-7mol L,n=11);采样频率为144次 h。该方法可用于葡萄酒和中药虎杖中白藜芦醇苷的测定。     

基于I--N-氯代丁二酰亚胺-鲁米诺反应体系流动注射化学发光法测定白藜芦醇

基于在碱性介质中,白藜芦醇对I-增强N-氯代丁二酰亚胺-鲁米诺化学发光体系的阻抑作用,建立了测定白藜芦醇的流动注射化学发光分析新方法.优化了流动注射化学发光的分析条件和探讨了反应的可能机理.测定白藜芦醇的线性响应质量浓度范围为2.5×10-9～8.0×10-8g·mL-1,检出限为6.3×10-10g·mL-1,用5.0×10-8g·mL-1的白藜芦醇标准溶液进行11次测定,相对标准偏差(RSD)为2.2%.应用本法测定了虎杖、葡萄酒、葡萄皮样品中的白藜芦醇含量,结果满意.     

高效液相色谱-串联质谱法检测红葡萄酒中功效成分

建立了高效液相色谱-串联质谱法快速测定葡萄酒中白藜芦醇、黄酮类、多酚类功效成分的分析方法。葡萄酒样品直接稀释后进样,用C18柱进行分离,以乙腈-0.1%(体积分数)甲酸水溶液为流动相进行梯度洗脱,通过多反应监测(MRM)模式进行检测。13种功效成分在各自线性范围内呈良好的线性关系,相关系数均大于0.99。除表没食子儿茶素、没食子儿茶素、儿茶素没食子酸酯、花旗松素的检出限为1.0、1.0、3.0、3.0μg/L外,其他9种化合物的检出限均小于1.0μg/L。回收率为80.9%~112.3%,相对标准偏差小于10%。该方法快速、准确、灵敏度高,适用于葡萄酒中功效成分的快速分析。对实际样品的检测表明,所测葡萄酒样品中均含有儿茶素、表儿茶素、表没食子儿茶素、没食子儿茶素、表儿茶素没食子酸酯/儿茶素没食子酸酯、白藜芦醇、大豆黄素等功效成分,不同品种葡萄酒中这些功效成分含量差异显著。     

高效液相色谱法测定红葡萄酒中白藜芦醇的四种异构体

将红葡萄酒用β-葡萄糖苷酶水解处理,使其中的白藜芦醇甙转换成白藜芦醇。采用高效液相色谱法测定水解前后顺、反式白藜芦醇含量的变化,从而计算出葡萄酒中白藜芦醇的4种异构体的含量。色谱柱为Symmetry C18柱(3.9 mm i.d.×150 mm),流动相为乙醇-0.05%乙酸水溶液(体积比为23∶77),紫外检测波长为306 nm。实验结果表明:白藜芦醇的4种异构体在其质量浓度为0.2~50.0 mg/L时均有良好的线性关系(r>0.999),白藜芦醇及其甙的顺、反异构体的最小检出量分别为:0.81     

Resveratrol content of some wines obtained from dried Valpolicella grapes: Recioto and Amarone

Resveratrol (rans-3,5,4'-trihydroxystilbene), a phenolic substance present in both grape skin and wines, is a phytoalexin involved in grey mould resistance. A new interest has surfaced in recent years related to the antioxidative actions of resveratrol, which in vivo could be related to the prevention of cardiovascular diseases linked to lipid metabolism, particularly HDL production, while the antifungal activity may be of interest in wine production technology. These aspects have led to the publication of a number of papers reporting data on the resveratrol content of several kind of wine: for Italian wines, it ranges between 0.5 and 10 ppm, depending on cultivar, area of cultivation, climate and wine-making technology. In this work, resveratrol was quantified in samples of two unusual Italian wines, Recioto (sweet) and Amarone (dry), produced with the same cultivar mixture in the same area (Valpolicella, Verona, Italy) and with the same grape conditioning technique. After resveratrol extraction, reversed-phase HPLC analysis was carried out and several elution conditions were tested. The resveratrol content of Recioto and Amarone wines was lower than the values reported in the literature for other wines, ranging between 0.05 and 0.8 ppm.     

Direct liquid chromatographic analysis of resveratrol derivatives and flavanonols in wines with absorbance and fluorescence detection

Wine contains a large number of polyphenols including stilbenes, flavanols and anthocyanins. Of these, stilbenes have been reported to have potential chemopreventive activities. We describe the simultaneous determination of six resveratrol derivatives in wines by liquid chromatography (LC) with fluorescence detection. The levels of pallidol, the symmetrical dimer of resveratrol, are reported for the first time. Quantifications were carried out at optimal wavelengths for each compound during separation. A total of 19 red and 30 white commercial wines from South-Western France were analysed, and the highest stilbene concentrations were found in red wines. In addition, the levels of catechins and two flavanonols recently isolated in red wine are reported.     

Techniques for resveratrol silylation

Summary Resveratrol, a wine stilbene phytoalexin with some pharmacological properties, was extracted from red wines by MeOH elution of a Sephadex LH-20 column, used for its purification. The column extract was dried and silylated by different methods to optimize resveratrol derivatization. The resveratrol analysis was by gas chromatography and gas cromatography-mass spectrometry allowing determination of its two isomers.     

Characterization of Wines by Trans-Resveratrol Concentration: A Case Study of Romanian Varieties

The goal of this study was to determine the trans-resveratrol concentration in wine. A set of 70 wine samples from Romania, produced according to the appellation of origin system, were analyzed by reverse-phase high performance liquid chromatography. White wines were found to have markedly lower concentrations of trans-resveratrol in comparison with red wines. The values were between 0.025 to 10.23 mg/L for red wine and from 0.074 to 2.572 mg/L for white wine. Red wine is a good dietary source of resveratrol.     

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.     

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.

     

Partial least squares and principal components analysis of wine vintage by high performance liquid chromatography with chemiluminescence detection

HPLC with acidic potassium permanganate chemiluminescence detection was employed to analyse 17 Cabernet Sauvignon wines across a range of vintages (1971-2003). Partial least squares regression analysis and principal components analysis was used in order to investigate the relationship between wine composition and vintage. Tartaric acid, vanillic acid, catechin, sinapic acid, ethyl gallate, myricetin, procyanadin B and resveratrol were found to be important components in terms of differences between the vintages.     

Role of Resveratrol in Prevention and Control of Cardiovascular Disorders and Cardiovascular Complications Related to COVID-19 Disease: Mode of Action and Approaches Explored to Increase Its Bioavailability

Resveratrol is a phytoalexin produced by many plants as a defense mechanism against stress-inducing conditions. The richest dietary sources of resveratrol are berries and grapes, their juices and wines. Good bioavailability of resveratrol is not reflected in its high biological activity in vivo because of resveratrol isomerization and its poor solubility in aqueous solutions. Proteins, cyclodextrins and nanomaterials have been explored as innovative delivery vehicles for resveratrol to overcome this limitation. Numerous in vitro and in vivo studies demonstrated beneficial effects of resveratrol in cardiovascular diseases (CVD). Main beneficial effects of resveratrol intake are cardioprotective, anti-hypertensive, vasodilatory, anti-diabetic, and improvement of lipid status. As resveratrol can alleviate the numerous factors associated with CVD, it has potential as a functional supplement to reduce COVID-19 illness severity in patients displaying poor prognosis due to cardio-vascular complications. Resveratrol was shown to mitigate the major pathways involved in the pathogenesis of SARS-CoV-2 including regulation of the renin-angiotensin system and expression of angiotensin-converting enzyme 2, stimulation of immune system and downregulation of pro-inflammatory cytokine release. Therefore, several studies already have anticipated potential implementation of resveratrol in COVID-19 treatment. Regular intake of a resveratrol rich diet, or resveratrol-based complementary medicaments, may contribute to a healthier cardio-vascular system, prevention and control of CVD, including COVID-19 disease related complications of CVD.