Method I is a classical phenol/ chloroform extraction approach. Methods II or III was modified from the method I by introducing methoxyethanol or ethyl ether for removal of polysaccharides, respectively. Experiments were performed in triplicates. 方法Ⅰ为经典的饱和酚-氯仿抽提方法,方法Ⅱ与方法Ⅲ都在方法Ⅰ操作基础上进行了改进,分别增加了乙二醇甲醚或水饱和乙醚的步骤以去除多糖。