Zhou Hao;Yang Jin;Zhang Yuhong;Jilin University;Northeast Forestry University;

Senna occidentalis;;Emodin;;Response surface methodology;;Purification method;;Column chromatography;;LC-MS;;HPLC

Taking the stem of Senna occidentalis as the experimental material, the optimal extraction solvent was screened, four factors including hydrochloric acid dosage, ethanol concentration, extraction time and extraction temperature were selected, on the basis of the single-factor experiment, and the content of emodin in S. occidentalis stem as the response value, the Design-Expert V.12 software Box-Benhnken design was used to carry out a four-factor and three-level experiment. The optimal process of Heating Reflux Method(HRM) for extracting emodin from S. occidentalis stems was optimized by response surface methodology, and the separation and purification of emodin was performed on this basis. The feasibility of obtaining high-purity emodin from S. occidentalis stems was discussed, and a set of reasonable and feasible identification methods were established. The results showed that the optimal process parameters for HRM of emodin in S. occidentalis stem were: ethanol was used as extraction solvent, 2 mL of hydrochloric acid per 20 mL of extraction solvent, 88% ethanol concentration, 86 min of extraction time, and 84 ℃ of extraction temperature. The emodin extract was obtained under the most optimal conditions by using chloroform extraction combined with pH gradient alkaline solution separation and silica gel column chromatography. HPLC and LC-MS were used for qualitative and quantitative analysis, the purity of emodin obtained after purification was 95.8%.