Studies On The Extraction Technology Of Anthraquinones From Rheum Spiciforme Royle

Rhubarb is a commonly used clinical medicine. The main active ingredients of rhubarb are anthraquinones, which have multi-functions including antibacterial, antioxidant and antimutagen, etc. The demand of rhubarb is increasing, but the resource of official rhubarb is relatively limited, therefore, some resourceful unofficial rhubarb is becoming the succedaneum. Rheum spiciforme Royle pertains to the Rheum genus of polygonaceae family. Correlative research about Rheum spiciforme Royle is seldom. The extraction technology condition of anthraquinones from Rheum spiciforme Royle is systematically studied in this paper for the first time, which will provide the experimental data and academic reference for the exploitation and utilization of rhubarb.In this paper, the content of anthraquinones is determined by UV and TLC-scanning, and the two analysis methods are compared. The UV method can determine the content of anthraquinones quickly, the average recovery rate is99.86%, RSD is1.49%. The TLC-scanning method can determine contents of five kinds of anthraquinones accurately, the average recovery rate of emodin, chrysophanol, aloe-emodin, rhein and physcion is99.05%、99.7%、99.67%、99.00%、99.33%respectively, RSD is1.27%、0.97%、1.20%、1.87%、2.05%respectively. These two methods are simple, financial, fast and accurate, and can be used as the determination method of evaluation index in the extraction process of total anthraquinones in Rhubarb. It also could provide useful experience for the content determination of anthraquinones in other drugs or preparations.This paper especially studies the technological conditions of extracting anthraquinones from Rheum spiciforme Royle by supercritical carbon dioxide fluid extraction (SFE-CO2). The content of anthraquinones is used as investigating targets; various factors that affect extraction effect are studied. The optimum extraction technology conditions of SFE-CO2are obtained through the orthogonal experiment. The result is as followed:hydrolyze the matrix by5mol·L-1hydrochloric acid (contrast to matrix1:1v:w), extraction pressure25MPa, extraction temperature45℃, the rate flow of CO222L·h-1,95%ethanol as entrainer (contrast to matrix2:1v: w) and extraction time2.5h. The extract yield is3.58%, the total anthraquinone extraction rate is2.12%. The craft enlargement experiment is also researched under the optimum condition.Traditional solvent extraction method is also studied in this paper. Based on the results of single factor experiments and orthogonal experiments, the best extracting procedures is extracting materials with6times amount of95%ethanol at80℃for6hours. The extract yield is10.52%, the total anthraquinone extraction rate is1.93%. Compared with the supercritical CO2extraction, the result shows that the quality of product extracted by SFE-CO2is better than traditional solvent extraction. The content of total anthraquinone extracted by SFE-CO2is up to59.2%, without further purification, it will fit the new drugs application requirements. Considering the influence of every aspect, the extracting of anthraquinones by SFE-CO2is of the industrial value and has great potential for development.