Extraction and Determination of Emodin and Chrysophanol Contents in Semen Cassiae.
Abstract:ObjectiveTo compare and research on various methods for extraction of emodin and chrysophanol from Semen Cassiae.MethodsThe emodin and chrysophanol were extracted by methanol or ethanol by means of ultrasonic or refluxing respectively. The emodin and chrysophanol contents were determined by RPHPLC methods.ResultsUltrasonic with methanol was the best extracting method for both emodin and chrysophanol. ConclusionThis method is meaningful for extraction and exploration of emodin and chrysophanol contents in Semen Cassiae.
Key words:Semen Cassiae; HPLC; Methods of extraction
决明子(Semen Cassiae)为豆科植物决明Cassia obtusifolia L.或小决明Cassia tora L.的干燥成熟种子,含有多种营养保健和药用成分,具有降血压、降血脂、保肝和抑菌等功效,其主要有效成分为蒽醌类化合物(大黄素、大黄酚等)[1]。由于决明子中大黄素、大黄酚的含量很低,如何提高其提取效率成为中药研究的重点和难点。2005版《中国药典》[2]中采用的是甲醇回流法,但是甲醇有较强的毒性,极易渗透进入皮肤对人体造成危害。考虑到大黄素和大黄酚均为极性分子,因此能否利用安全性更高和成本更低廉的乙醇来替代甲醇值得研究。回流提取决明子是常用的方法[3~5],但是大量有机溶剂的使用会导致环境污染,成本增加,有机溶剂残留等问题。相比较而言,超声波提取作为提取工艺的新兴技术,其应用范围因其高效、绿色、廉价、操作简单而越来越广[6]。若能用超声波提取决明子大黄素和大黄酚,将非常值得推广。本文利用反相高效液相色谱(RPHPLC)方法,比较了甲醇、乙醇分别采用超声波、回流方法提取决明子大黄素和大黄酚的结果。现报告如下。
1 仪器与材料
岛津高效液相色谱系统:ODSC18色谱柱,LC6AD泵,SPDM10AVP紫外检测器,Shidamzu色谱工作站;FA1004电子天平(上海天平);Beckman高速冷冻离心机;Millipore超纯水制备器和0.45 μm滤膜;KQ2200DB超声波;DHG9240A恒温干燥箱;决明子药材购于峨眉山市医药公司,并经西南交通大学药学院宋良科教授鉴定为豆科植物小决明(Cassia tora L.)的干燥成熟种子;大黄酚对照品(中国药品生物制品检定所,批号110796200514);大黄素对照品(中国药品生物制品检定所,批号110756200110);甲醇为色谱纯;其余试剂均为国产分析纯。