一点红黄酮成分的分析及含量测定

对一点红中黄酮类成分进行了定性分析和定量测定，结果表明，在一点红中含有黄酮、黄酮醇、二氢黄酮、二氢黄酮醇等多种黄酮类化合物，并以芦丁为标样，用分光光度法测出总黄酮含量为4．02％。  

山豆根化学成分研究

利用多种柱层析方法，从山豆根中分得5个化合物。经过理化及波谱分析，分别鉴定为L-广高丽槐素(1)、红车轴草苷(2)、槲皮素(3)、芦丁(4)和异鼠李素-3-芸香糖甙(5)。其中化合物3,5为首次从该植物中分离得到。关键词：山豆根；L-高丽槐素；红车轴草苷；槲皮素；芦丁；异鼠李素-3-芸香糖甙  

A peroxidase/phenolics/ascorbate system can scavenge hydrogen peroxide in plant cells

The function of a peroxidase/phenolics/ascorbic acid system in plant vacuoles has not yet been well elucidated. We wished to study the redox reactions among hydrogen peroxide, phenolics and ascorbic acid (AA) in the presence of horseradish peroxidase. Horseradish peroxidase oxidized rutin and chlorogenic acid (CGA), compounds present in many kinds of plant. The oxidation was inhibited by AA. As a result of the inhibition. AA was oxidized and when almost all of it had been oxidized, oxidation of the phenolics commenced. Monodehydroascorbic acid (MDA) radical was detected during the oxidation of AA, suggesting that the inhibition of oxidation of rutin and CGA was due to reduction of phenoxyl radicals by AA. By comparison of time courses of changes in levels of AA and MDA radicals, and by kinetic calculation, it is suggested that in addition to AA, MDA radicals may also reduce phenoxyl radicals. It is proposed that the peroxidase/phenolics/AA system can function as a hydrogen peroxide scavenging system.  

不同产地烤烟叶中绿原酸和芸香苷的含量分析

为了探索绿原酸和芸香苷的新型植物资源和生物活性,同时为低等级烤烟叶的综合利用开辟有效途径,本文采用高效液相色谱技术,对中国和湖南省不同生态烟区以及不同部位烤烟叶中绿原酸和芸香苷的含量进行了研究。结果表明,东北烟区低等级烤烟叶中的绿原酸和芸香苷含量很高;湖南省湘南烟区烤烟叶中绿原酸和芸香苷含量显著高于湘北和湘中烟区;不同部位烤烟叶中绿原酸含量差异不显著,芸香苷含量差异极显著,并且上部叶>中部叶>下部叶。  

蔓茎堇菜总黄酮提取工艺初探

分别采用热水浸提法、甲醇浸提法和乙醇浸提法来提取蔓茎堇菜样品的总黄酮，并以芦丁为标准品，用紫外分光光度法在265nm处测定各提取液的总黄酮含量。结果表明，甲醇浸提法和乙醇浸提法显著优于热水浸提法，而用70％乙醇为提取溶剂时效果最佳。研究结果可为利用蔓茎堇菜工业化生产黄酮类药用成分提供科学依据。  

槲皮素体内外抗氧化作用的比较研究

目的 :测定槲皮素的体外总抗氧化力 ,进一步观察槲皮素灌胃后大鼠外周血总抗氧化力的变化 ,并与芦丁、维生素C、维生素E相比较。方法 :总抗氧化力采用Fe3 还原法 ,槲皮素、芦丁分析采用紫外分光光度法及高效液相色谱法。结果 :相同浓度条件下槲皮素的体外总抗氧化力显著强于芦丁 ,与传统的抗氧化剂维生素C、维生素E相当。槲皮素 4 0mg/kg灌胃 1h后大鼠外周血总抗氧化力及槲皮素含量 (紫外分光光度法 )较灌胃前升高最为明显。维生素C也有显著提高外周血总抗氧化力的作用 ,芦丁与维生素E未表现出显著作用。血浆高效液相分析表明槲皮素灌胃后未出现明显的槲皮素吸收峰 ,而与其峰相邻的两个未知峰的面积增大。结论 :槲皮素的体外抗氧化作用强于芦丁 ,与传统的抗氧化剂维生素C、维生素E相当 ;槲皮素吸收后经代谢形成衍生物 ,提高血浆总抗氧化力的程度与维生素C相近  

芦丁和槲皮素对低密度脂蛋白氧化修饰的抑制作用

以低密度脂蛋白（ＬＤＬ）氧化修饰为模型和以硫代巴比妥酸反应物质（ＴＢＡＳ）生成量以及ＬＤＬ的α－Ｔｏｃｏｐｈｅｒｏｌ和荧光物质含量为指标，以时间效应和浓度效应说明槲皮素和芦丁能明显地抑制Ｃａ＾２＋诱导的ＬＤＬ氧化修饰但其抗氧化修饰的程度无明显差异。它们对已受到Ｃｕ＾２＋氧化修饰的ＬＤＬ的过氧化无明显地终止作用。  

芦丁-锗配合物及其自由基清除活性研究

芦丁是存在于多种植物中的天然多羟基黄酮苷，能与多种金属离子形成配合物。本文采用紫外分光度法考察了芦丁与锗离子的配位作用，并研究了芦丁-锗配合物清除超氧自由基和DPPH自由基的作用。结果显示在KH2PO4-NaOH(pH6．70)的缓冲液中，芦丁与锗离子能形成1：1的配合物，其K稳=10^7.46，同时配合物显示有较好的自由基清除活性。  

Phenylpropanoids, phenylalanine ammonia lyase and peroxidases in elicitor-challenged cassava (Manihot esculenta) suspension cells and leaves

BACKGROUND AND AIMS: Control of diseases in the key tropical staple, cassava, is dependent on resistant genotypes, but the innate mechanisms are unknown. The aim was to study phenylpropanoids and associated enzymes as possible defence components. METHODS: Phenylalanine ammonia-lyase (PAL), phenylpropanoids and peroxidases (POD) were investigated in elicited cassava suspension cells and leaves. Yeast elicitor was the most effective of several microbial and endogenous elicitors. Fungitoxicity was determined against the cassava pathogens Fusarium solani, F. oxysporum and the saprotroph Trichoderma harzianum. KEY RESULTS: A single and rapid (> or =2-3 min) oxidative burst, measured as hydrogen peroxide, occurred in elicited cells. PAL activity was induced maximally at 15 h and was preceded by PAL mRNA accumulation, which peaked at 9 h. Symplasmic POD activity increased four-fold in cells, 48 h post-elicitation. POD isoforms (2-7 isoforms, pI 3.1-8.8) were detected in elicited and unelicited cells, extracellular medium and leaves but two extracellular isoforms were enhanced post-elicitation. Also expression of a cassava peroxidase gene MecPOD1 increased in elicited cells. Only anionic forms oxidized scopoletin, with highest activity by isoform pI 3.6, present in all samples. Unidentified phenolics and possibly scopolin increased post-elicitation, but there was no enhancement of scopoletin, rutin or kaempferol-3-O-rutinoside concentration. Fungal germ tube elongation was inhibited more than germination by esculetin, ferulic acid, quercetin and scopoletin. T. harzianum was generally more sensitive than the pathogens and was inhibited by > or =50 microg mL(-1) of ferulic acid and quercetin and > or =10 microg mL(-1) of scopoletin. CONCLUSIONS: Phenolic levels in cells were not enhanced and were, theoretically, too low to be inhibitory. However, in combination and when oxidized they may contribute to defence, because oxidation of esculetin and scopoletin by peroxidase and of esculetin by tyrosinase enhanced their fungitoxicity up to 20-fold.  

RP-HPLC法测定芦笋中黄酮类化合物芦丁的含量

以芦丁标准品为对照,利用反相高效液相色谱法对芦笋中黄酮类化合物芦丁的含量进行定量测定。采用Agilent Eclipse XDB-C18色谱柱,柱温25℃,流动相由甲醇-水-磷酸(55∶44.5∶0.5)组成,流速为0.7 mL/min,检测波长390 nm。结果表明黄酮类化合物中各组分基线分离良好;进样量在0.07~0.7μg/20μL范围内,峰面积A与进样浓度C呈良好的线性关系,回归方程为A=1 5176C-10.388,相关系数R2=0.999 4;加样回收率为101.051%,RSD=3.306%;以保留时间和峰面积作精密度试验,RSD分别为0.199%和1.24%。该方法样品处理简单,准确度高,精密度好,适合于芦笋中芦丁含量的测定。