青蒿富倍半萜提取物的稳定性及光物质转化的初步研究

Preliminary Study on Stability and Phototrans Formation of Sesquiterpene Rich Extract from Artemisia annua L.

目的 考察青蒿富倍半萜提取物在高温、高湿和强光照射条件下的稳定性,并初步探究在光照条件下倍半萜组分间的转化规律。方法 根据《原料药物与制剂稳定性试验指导原则》,对提取物进行高湿(相对湿度90%)、高温(60℃)、强光照射(4 500 lx)试验,考察其重量及含量变化,并对提取物、原药材及青蒿乙素(arteannuin B)、青蒿素(artemisinin)、青蒿酸(artemisinic acid)及二氢青蒿酸(dihydroartemisinic acid)的对照品进行30 d光照试验(4 500 lx),检测各倍半萜组分的含量变化,并应用液质联用(LC-MS)方法对光照后各对照样品进行定性分析。结果 提取物在高湿条件下于10 d内各检测成分无明显变化,高温及强光照条件下青蒿酸及二氢青蒿酸含量降低,强光照条件下青蒿素及青蒿丙素含量有所升高。经30 d照射后提取物及原药材中青蒿酸及二氢青蒿酸均显著降低,青蒿素明显升高,光照5 d后即可在二氢青蒿酸的对照品中检测到青蒿素,并随时间的增加,其含量持续上升。提取物、原药材及二氢青蒿酸对照品组的青蒿素平均转化率分别为75.33%、59.10%和1.29%。LC-MS定性结果显示二氢青蒿酸和青蒿酸经过30 d强光照射,分别产生了青蒿素与青蒿乙素。结论 作者首次发现了青蒿富倍半萜提取物的光反应转化现象,这提示该提取物在高温及光照条件下将导致物质组成的变化,应避光保存于阴凉处。此外,在以提取青蒿素单一化合物为目标时,原药材在采收后适当增加光照有助于提高其得率。

OBJECTIVE To investigate the stability of the rich sesquiterpene extract of Artemisia annua L. under high temperature, high humidity and strong light irradiation, as well as preliminarily explore the transformation rule of sesquiterpene components under light conditions. METHODS The extract was tested under high humidity(relative humidity 90%), high temperature(60 ℃) and strong light irradiation(4 500 lx) according to the "guiding principles for stability test of raw materials and preparations". The weight and content changes of the extract were investigated. Meanwhile, the content changes of sesquiterpene components of original medicinal material and the reference materials of arteannuin B, artemisinin, artemisinic acid and dihydroartemisinic acid were detected by 30 days strong illumination test(4 500 lx). LC-MS was used for qualitative analysis of reference substances after illumination. RESULTS There was no significant change in the detected components of the extract within 10 days in high humidity group, the contents of artemisinic acid and dihydroartemisinic acid decreased in high temperature and strong illumination group, and the contents of artemisinin and deoxyartemisinin also increased in strong illumination group. After 30 days of irradiation, artemisinin and dihydroartemisinic acid in the extract and original medicinal materials decreased significantly, and artemisinin increased significantly. Artemisinin could be detected in the reference substance of dihydroartemisinic acid after 5 days of illumination, and its content continued to increase with the accumulation of time. The average conversion rates of artemisinin in the extract, original medicine and control group were 75.33%, 59.10% and 1.29% respectively. LC-MS qualitative results showed that dihydroartemisinic acid and artemisinic acid produced artemisinin and arteannuin B respectively after 30 days of strong illumination.CONCLUSION This study finds the light reaction transformation of the extract for the first time, which suggests that the sesquiterpene rich extract of Artemisia annua will lead to the change of material composition under high temperature and strong light conditions. It should be stored in a cool place away from light. Besides, in order to obtain artemisinin, increasing the irradiation after harvest will help to improve its yield.