白藜芦醇和白藜芦醇苷抗氧化作用的研究

采用亚油酸体系、H2O2诱导的红细胞溶血试验研究白藜芦醇、白藜芦醇苷的体外抗氧化作用。研究结果表明:白藜芦醇、白藜芦醇苷能抑制亚油酸的过氧化作用,其抑制率高于VC、BHT、虎杖粗提物。白藜芦醇、白藜芦醇苷均可降低H2O2诱导红细胞氧化性溶血率,其作用效果好于VC、VE和虎杖粗提物,抑制率具有剂量效应。     

不同溶剂提取葡萄酒中白藜芦醇及其糖苷异构体

利用白藜芦醇及其糖苷异构体几乎不溶于水,易溶于有机溶剂的性质,比较了乙酸乙酯、氯仿、乙醚,乙酸乙酯与正己烷、二氯甲烷混合溶液及双水相体系对葡萄酒中白藜芦醇及其糖苷异构体的提取效果,得到了最佳的提取溶剂。结果表明:乙酸乙酯对目标化合物的提取效果优于其他有机溶剂,对白藜芦醇苷的提取率可达90%以上,对白藜芦醇的提取率低于80%。乙酸乙酯萃取操作简单、提取率较高,切实可行。      

不同产地虎杖药材中有效成分及其抑菌活性的比较

考察不同产地虎杖药材中主要有效成分的含量及其抑菌活性。采用乙醇加热回流法提取虎杖药材中的有效成分,分别测定白藜芦醇苷、大黄素含量,并测定了提取液的抑菌活性。结果发现,不同产地虎杖药材中白藜芦醇苷的含量有显著性差异,其中安徽产的含量最高,各地虎杖药材对金黄色葡萄球菌和枯草杆菌的抑菌活性均较强。     

Comparison of Procedures for Resveratrol Analysis in Beer: Assessment of Stilbenoids Stability through Wort Fermentation and Beer Aging

Three resveratrol extraction procedures were compared in beer. Two‐step pre‐cleaning with toluene and cyclohexane allows 76% trans‐resveratrol recovery by solid‐phase extraction (SPE) before RP‐HPLC‐MS/MS analysis. This procedure proved much more efficient than liquid/liquid extraction, which requires solvents that are too hydrophobic for stilbenoids. SPME‐GC‐MS, where the main limiting factor is non‐reproducibility from fibre to fibre, is an interesting alternative for resveratrol quantification in complex mixtures where pre‐cleaning is too difficult. With the optimized SPE procedure, 5 μg.L^?1 trans‐resveratrol was detected in four commercial beers. However, concentrations of stilbenoids in beer should be higher taking into account the presence of cis‐stilbenoids. During fermentation, trans‐resveratrol was partially regenerated from its glucoside, more stable through beer aging. Adding a stilbenoids‐enriched ethanolic hop extract after fermentation significantly increases the beer stilbenoids potential.     

不同单品种葡萄酒中白藜芦醇以及白藜芦醇苷含量的研究

采用高效液相色谱法测定了广西地区几个酿酒品种和野生品种的单品种葡萄酒中的白藜芦醇及其糖苷的含量。结果表明,巨峰冬葡萄酒以及两个野生品种G203和A3051的葡萄酒中白藜芦醇及其糖苷含量较高,其总含量分别达到1.505 mg/L、1.1728 mg/L和0.9389 mg/L。     

Resveratrol in Peanuts

Peanuts are important dietary food source of resveratrol with potent antioxidant properties implicated in reducing risk of cancer, cardiovascular and Alzheimer's disease, and delaying aging. Resveratrol is a naturally occurring stilbene phytoalexin phenolic compound produced in response to a variety of biotic and abiotic stresses. This paper is a review of trans-resveratrol and related stilbenes from peanuts—their chemical structures, mechanisms for their biosynthesis, and concentrations in comparison with other major food sources. It will also discuss trans-resveratrol's absorption, bioavailability, and major health benefits; processes to enhance their biosynthesis in peanuts by biotic and abiotic stresses; process optimization for enhanced levels in peanuts and their potential food applications; and methods used for its extraction and analysis.