基于抗氧化活性与有效成分关联分析的连翘商品规格品质评价

目的：对连翘药材的不同商品规格"青翘"、"老翘"、"青翘心"及"老翘心"进行品质评价。方法：采用清除DPPH自由基方法对不同商品规格连翘的抗氧化活性进行测定,以量效关系、IC₅₀等指标进行直观和定量比较;同时,通过高效液相色谱法（HPLC）测定样品中连翘苷、连翘酯苷A、槲皮素、牛蒡子苷元及牛蒡子苷的含量,以相关分析及多元线性逐步回归分析进行抗氧化活性与化学成分之间的关联。结果：连翘具有较强清除DPPH自由基活性,IC₅₀大小为：青翘心 > 青翘 > 老翘心 > 老翘 > 维生素E,HPLC测连翘酯苷A与槲皮素的含量为：青翘心 > 老翘心 > 青翘 > 老翘,连翘酯苷A及槲皮素、牛蒡子苷元分别与IC₅₀呈极显著及显著负相关关系,多元线性逐步回归分析显示槲皮素的含量增加有助于清除DPPH自由基水平的提高,槲皮素与牛蒡子苷元可能有协同作用。结论：不同商品规格的连翘抗氧化活性为"青翘"优于"老翘"、"心"优于"皮",连翘酯苷A含量最高,且连翘酯苷A及槲皮素含量越多,连翘商品的抗氧化性越强,所建立方法把抗氧化活性与化学成分关联对不同规格连翘商品的品质进行评价,可以为完善和提高连翘的质控水平提供技术支持与研究思路的参考。

The associative analysis of antioxidative activities and effective ingredients of different commercial grades of Forsythia Suspensa

OBJECTIVE To evaluate quality of different commercial grades of Fructus Forsythiae, including Green Fructus Forsythiae,Grown Fructus Forsythia,the seed of Green Fructus Forsythiae and the seed of Grown Fructus Forsythiae.METHODS Ultrasonic assisted technology was applied to extract different samples with 95% ethanol, then the extracts were vacuum filtrated, concentrated, dried, diluted to required concentrations. VE was the positive control drug. The antioxidant activities were evaluated in vitro through scavenging effects to DPPH free radicals, to study the methodology repeatability, stability and accuracy of the instrument according to the basic requirements of drug testing. The established method was used to determine the four samples then compared them directly and quantitatively with the curve of dose effection and IC₅₀ as index. Moreover, the contents of forsythin, forsythoside A, quercetin, arctigenin and arctiin in different samples were determined using HPLC chromatography, and then the relationship between antioxidant activity and chemical composition was evaluated by correlation analysis and multiple linear regression analysis.RESULTS Forsythia had strong DPPH radical scavenging activity in each sample, IC₅₀ was ordered in the seed of Green Fructus Forsythiae > Green Fructus Forsythiae > the seed of Grown Fructus Forsythiae > Grown Fructus Forsythia > VE. Forsythoside A and quercetin pigment contents were ordered as follows:the seed of Green Fructus Forsythiae > the seed of Grown Fructus Forsythiae > Green Fructus Forsythiae > Grown Fructus Forsythia. There was very significant correlations between forsythoside A, quercetin and IC₅₀, and significant relationship between arctigenin and IC₅₀. The multiple linear stepwise regression analysis showed that quercetin helped remove DPPH radicals, quercetin and arctigenin might have synergistic effects.CONCLUSION The four samples have different antioxidant activities, and varied chemical contents. The established method in this paper can correct the antioxidant activity and chemical contents to evaluate and distinguish the quality of Forsythia suspensae. Importantly, it can improve and enhance the level of quality control of forsythia and give a new light to this field.