化学转化法间接测定当归药材中药效标志物藁本内酯含量的方法研究及应用

Development and application of a chemical transformational method for the indirect measurement of ligustilide content in Angelica sinensis

藁本内酯化学结构决定其稳定性较差,无合格的藁本内酯对照品供应,无法满足含量控制的需求,本文通过关键转化反应条件的优化、HPLC-DAD方法学研究建立了间接测定当归药材中藁本内酯含量的方法,并分析大样本的含量测定数据为国家药典标准提出建议。研究确定机械搅拌下通过甲醇/环丙胺混合反应、提取溶剂对药材粉末的提取、反应同步处理以及超声辅助提取、反应处理过程可以达到稳定和转化藁本内酯的双重效果;通过外标法准确测定转化液中的环丙藁本含量进而间接计算当归药材中的藁本内酯的含量。对68份药材原产地样本(甘肃、青海)、55份商品样本和21份明确储存期1.5年及以上样本的测定,显示80%主产区当归药材中藁本内酯的含量在1.0%以上。研究表明,化学转化法可以间接准确测定当归药材中藁本内酯的含量,可以评价以藁本内酯为主药效成分的中药材(如当归、川芎)或中成药的质量优劣。建议中国药典参照香港中药材标准,规定商品当归药材中藁本内酯的含量不得低于0.6%,不再采用挥发油总量和阿魏酸作为定量检测指标。

The poor stability of the ligustilide(LIG)makes its quantitation in Angelica sinensis(AS)difficult.This study establishes a chemical conversion method for the determination of ligustilide content in AS and proposes a national pharmacopoeia standard.Mechanical agitation and sonication of a powdered AS extract in a methanol/cyprolamine mixture facilitated the stabilization and transformation of ligustilide.Using an external reference HPLC-DAD method,the cyclopropyl-ligustilide(LIGc)content in the mixture could be determined.The content of ligustilide was greater than 1.0%based on 144 AS specimens including 68 obtained from the originally planted areas of Qinghai and Gansu Province;55 specimens were obtained from Minxian and Weiyuan County medicine markets,and 21 specimens for which the storage period reached or exceeded 1.5 years.According to the Hong Kong Chinese materis medica standards,the content of ligustilide in AS should not be lower than 0.6%.The developed method could also be applied to the quality control of other Chinese medicinal materials(such as Ligusticum chuanxiong)or Chinese patent medicines in which ligustilide is the main component.