微波连续抽提用于灵芝三萜类成分的分析

Analysis of triterpenoids in Ganoderma lucidum by microwaveassisted continuous extraction

结合索氏提取的原理,自制了微波连续抽提装置,通过与传统方法的比较,研究了微波连续抽提法的特点和萃取效率,并将其用于灵芝三萜类成分的分析。该法的萃取条件为:以95%乙醇为萃取溶剂,微波功率200 W,微波时间14.5 min(5个循环)。将上述条件下的萃取结果与传统的回流提取、索氏提取、超声提取和微波萃取法进行比较。结果,微波连续抽提和常规的微波萃取分别需要14.5,10 min即可将灵芝三萜类成分的提取量达到最高,而其他非微波提取的方法则需要几十分钟甚至上百分钟。微波萃取10 min与回流提取120 min所得灵芝三萜的量基本一致,明显高于索氏提取和超声提取法,同时又远低于微波连续抽提法。更为重要的是,由三萜提取量所占粗提物的比例可知,微波连续抽提所得提取物的纯度远远优于其他方法。微波连续抽提有效结合了微波萃取和索氏提取的优点,因此比常规的微波萃取更能将药材中的目标成分提取完全,使分析结果更为准确,为中药的成分分析提供了一种新颖的、高效、快速、可靠的样品前处理技术。同时,由于该方法提高了药材利用率,并且所得提取物具有杂质含量低,有效成分含量高的特点,也可将其用于中药成分的制备和提取工艺的研究。

For further improving the extraction efficiency of microwave extraction, a microwave-assisted continuous extraction （MACE） device has been designed and utilized. By contrasting with the traditional methods, the characteristics and extraction efficiency of MACE has also been studied. The method was validated by the analysis of the triterpenoids in Ganoderma lucidum. The extraction conditions of MACE were：using 95% ethanol as solvent, microwave power 200 W and radiation time 14.5 min （5 cycles）. The extraction results were subsequently compared with traditional heat reflux extraction （HRE）, soxhlet extraction （SE）, ultrasonic extraction （UE） as well as the conventional microwave extraction （ME）. For triterpenoids, the two methods based on the microwaves （ME and MACE） were in general capable of finishing the extraction in 10, 14.5 min, respectively, while other methods should consume 60 min and even more than 100 min. Additionally, ME can produce comparable extraction results as the classical HRE and higher extraction yield than both SE and UE, however, notably lower extraction yield than MASE. More importantly, the purity of the crud extract by MACE is far better than the other methods. MACE can effectively combine the advantages of microwave extraction and soxhlet extraction, thus enabling a more complete extraction of the analytes of TCMs in comparison with ME. And therefore makes the analytic result more accurate. It provides a novel, high efficient, rapid and reliable pretreatment technique for the analysis of TCMs, and it could potentially be extended to ingredient preparation or extracting techniques of TCMs.