栀子的化学成分

目的：对栀子（Gardenia jasminoides Ellis）的化学成分进行研究。方法：采用不同柱色谱技术进行分离,通过波谱分析确定化合物结构。结果：分离鉴定了14个化合物,其中6个为黄酮类化合物,分别为croymbosin（1）、槲皮素（2）、芦丁（3）、umuhengerin（4）、nicotiflorin（5）、异槲皮苷（6）;8个为有机酸类,分别为绿原酸（7）、3,4-二咖啡酰奎宁酸（8）、3-咖啡酰-4-芥子酰奎宁酸（9）、3-咖啡酰-4-芥子酰奎宁酸甲酯（10）、3-咖啡酰-5-芥子酰奎宁酸甲酯（11）、3,4-二咖啡酰-5-（3-羟-3-甲基）戊二酰奎宁酸（12）、3,5-二咖啡酰-4-（3-羟-3-甲基）戊二酰奎宁酸（13）、原儿茶酸（14）。结论：化合物2～6和14为首次从该植物中分离得到,其中化合物2,3,5,6和14系首次从该属植物中分离得到。     

正交实验优选地黄叶中梓醇的提取工艺

目的对干地黄叶中梓醇的提取方法进行优选，确定最佳提取工艺。方法采用正交实验表L8（2）^7安排实验。结果提取方法对梓醇提取率影响最大。结论确定地黄叶中梓醇的最佳提取工艺，即加水煎煮提取，提取次数为2次，1h／次。     

流动注射化学发光法研究黄酮等物质清除超氧自由基的作用

目的建立化学发光新方法以考察黄酮等物质对超氧自由基的清除作用。方法以碱性条件下邻苯三酚自氧化作为超氧阴离子的产生体系，以化学发光的降低作为检测活力的指标。结果杭白菊、马齿苋、槲皮素、芦丁都表现出对超氧阴离子自由基的清除作用。结论该方法简单、快速，可用于中草药抗氧化活性研究。     

高效液相色谱法测定山楂叶提取物中熊果酸的含量

目的:建立山楂叶提取物中熊果酸的含量测定方法。方法:高效液相色谱法,C18柱,以甲醇-水-磷酸(90∶10∶0.03)为流动相,流速为0.5mL·min-1,检测波长为220nm。结果:熊果酸在(0.982~9.82)μg·mL-1范围内与峰面积线性关系良好,相关系数为0.9998,平均回收率为98.16%,RSD为0.58%(n=6)。结论:方法简便,准确,重复性好,适用于山楂叶提取物的质量控制。     

雪莲果叶片多糖的微波提取技术改进

本实验以雪莲果(Smallanthus sonchifolius)叶片多糖的提取率为评价指标,比较了微波提取法与传统热水提取法对雪莲果叶片多糖提取率的影响,并采用两因素三水平的实验设计对微波提取法进行了研究。结果表明:采用微波技术提取雪莲果叶中的多糖比采用传统的热水提取法更有效,并且根据方差分析和多重比较结果确定了采用微波技术提取雪莲果叶片多糖工艺的优选方案为:280W微波功率进行2次提取,每次15 min。     

Absorption and DNA protective effects of flavonoid glycosides from an onion meal

Summary Background. It is widely believed that antioxidant micronutrients obtained from fruit and vegetables afford significant protection against cancer and heart disease, as well as ageing. Flavonoids are potential antioxidants found in food such as onions; information on their effectiveness in vivo is so far lacking. Aims. To determine uptake as well as in vivo antioxidant effects of flavonoids from foods. Methods. Six healthy non-obese normocholesterolaemic female volunteers in the age range 20–44 years participated in a randomised two-phase crossover supplementation trial to compare the antioxidant effects associated with (a) a meal of fried onions and (b) a meal of fried onions and fresh cherry tomatoes. Plasma flavonoids, lymphocyte DNA damage, plasma ascorbic acid, tocopherols and carotenoids, urinary malondialdehyde and 8-hydroxy-2’-deoxyguanosine were determined to assess flavonoid absorption and antioxidant efficacy. Results. Flavonoid glucosides (quercetin-3-glucoside and isorhamnetin-4-glucoside) were significantly elevated in plasma following ingestion of the onion meal and the increases were associated with an increased resistance of lymphocyte DNA to DNA strand breakage. A significant decrease in the level of urinary 8-hydroxy-2’-deoxyguanosine was evident at 4 h following ingestion of the onion meal. After the combined tomato and onion meal, only quercetin was detected in plasma. Endogenous base oxidation was decreased but resistance to strand breakage was unchanged. There was no significant change in the excretion of urinary malondialdehyde following either meal. Conclusion. Both meals – onions, and onions together with tomatoes – led to transient decreases in biomarkers of oxidative stress, although the particular biomarkers affected differ. It is possible that the differences in patterns of response reflect the different uptakes of flavonoids but the underlying mechanism is not understood. Received: 1 April 2000, Accepted: 1 August 2000     

In vitro receptor screening of pure constituents of St. John's wort reveals novel interactions with a number of GPCRs

RATIONALE: Hypericum perforatum L. (St. John's wort; SJW) is one of the leading psychotherapeutic phytomedicines and great effort has been devoted to clarifying its mechanism of action. OBJECTIVE: We have undertaken a comprehensive analysis of several pure compounds isolated from the crude extract to gain further insight into the molecular actions of various substituents of SJW. METHODS: We characterized the in vitro pharmacology of the naphthodianthrones hypericin and pseudohypericin, the phloroglucinol derivative hyperforin, and several flavonoids at 42 biogenic amine receptors and transporters using the resources of the National Institute of Mental Health Psychoactive Drug Screening Program. RESULTS: The biflavonoid amentoflavone significantly inhibited binding at serotonin (5-HT(1D), 5-HT(2C)), D(3)-dopamine, delta-opiate, and benzodiazepine receptors. The naphthodianthrone hypericin had significant activity at D(3)- and D(4)-dopamine receptors and beta-adrenergic receptors. With the exception of the D(1)-dopamine receptor, the phloroglucinol derivative hyperforin was less active than other SJW constituents tested on all screened receptors. CONCLUSION: Our present in vitro data clearly show that several pure substances in SJW are potential CNS psychoactive agents and may contribute to the antidepressant efficacy of the plant in a complex manner. Our data also reveal novel and heretofore unexpected interactions of pure compounds in SJW at a number of GPCRs, transporters, and ion channels. We hypothesize that additive or synergistic actions of different single compounds may be responsible for the antidepressant efficacy of SJW. These results and this general approach may impact our understanding of phytomedicines in general and H. perforatum specifically.     

Stability and antioxidant activity of polyphenols in extracts of Myrtus communis L. berries used for the preparation of myrtle liqueur

Flavonoids and anthocyanins in berry extracts from Myrtus communis, prepared by following a typical Sardinia myrtle liqueur recipe, were identified by HPLC coupled with Electrospray Mass Spectrometry and quantified by HPLC coupled with Ultraviolet/Visible Detection in order to evaluate the stability of the extracts during 1 year of storage. Antioxidant activity was measured by using TEAC assay, and the free-radical scavenging activity was monitored during time of the stability evaluation.Anthocyanins have found to be the most instable compounds, but a considerable instability was observed also for flavonoids, suggesting the use of extracts not over 3 months from their preparation. The myrtle extract showed interesting free-adical scavenging activity. Antioxidant activity was preserved in 3 months.     

马蔺地下部分的化学成分

目的:研究鸢尾科鸢尾属植物马蔺(Iris lactea Pall.var.chinensis(Fisch.)koidz.)地下部分的化学成分.方法:采用70%乙醇提取,硅胶柱层析分离及重结晶等方法分离其化学成分,通过波谱及化学方法进行结构鉴定.结果:分离并鉴定了10个化合物,分别为:5-羟基-7-甲氧基黄酮(tectochrysin,Ⅰ)、5,2'-二羟基-6,7-亚甲二氧基二氢黄酮(5,2'-dihydroxy-6,7-methylenedioxyflavanone,Ⅱ)、5,7-二羟基-6,2'-二甲氧基异黄酮(5,7-dihydroxy-6,2'-dimethoxyisoflavone,Ⅲ)、4',5-二羟基-6,7-二甲氧基异黄酮(4',5-dihydroxy-6,7-dimethoxyisoflavone,Ⅳ)、4',5,7-三羟基-6-甲氧基异黄酮(tectorigenin)(4',5,7-trihydroxy-6-methoxyisoflavone,Ⅴ)、5,3'-二羟基2'-甲氧基-6,7-亚甲二氧基异黄酮(5,3'-dihydroxy-2'-methoxy-6,7-methylenedioxyisoflavone,Ⅵ)、5,2'-二羟基-6,7-亚甲二氧基异黄酮(5,2'-dihydroxy-6,7-methylenedioxyisoflavone,Ⅶ)、irisoid D(Ⅷ)、irisoid A(Ⅸ)和十七烷酸(heptadecanoic acid,X).结论:这些化合物均为在该植物中首次分得,其中化合物Ⅵ为本属植物中首次发现.     

Development of a database of critically evaluated flavonoids data: application of USDA's data quality evaluation system

The USDA Special Interest Database for flavonoid content of selected foods contains 26 most abundant compounds within 5 predominant subclasses of flavonoids–flavonols, flavones, flavanones, flavan-3-ols, and anthocyanidins. All the data were evaluated for 5 quality evaluation categories (sampling plan, sample handling, analytical method, analytical quality control and number of samples), using the data quality evaluation system developed by the USDA scientists. Confidence Codes (A–through D) were then assigned to every value. The database contains acceptable values for 225 selected foods. Only 97 sources out of approximately 475 collected included acceptable analytical data. The overall quality of data was good with 64% of the observations receiving A or B confidence codes; the flavan-3-ols subclass received better ratings than other subclasses. While this is the first comprehensive database for flavonoids in foods, the majority of data came from Europe and countries other than the US. Due to the observed variability in the values it will be important to have data for US foods. The evaluation of data quality helps set priorities and further identifies the foods to be analyzed as well as areas to improve data quality. Furthermore, release of data quality confidence codes with data provides necessary information to investigators to assess the impact of flavonoid intake on risk of various chronic diseases.