Optimization of extract process of anthraquinones from Rhei Radix et Rhizoma by orthogonal test / 中草药

ABSTRACT

Objective: To optimize the extract process of anthraquinones from the Rhei Radix et Rhizoma (RRR). Methods: The contents of eight bound anthraquinones (Bas) and five free anthraquinones (Fas), a total of 13 original anthraquinones, and total anthraquinones (Tas) in RRR were determined by HPLC. L9(34) orthogonal table was used, with ethanol concentration, solvent ratio, extract time, and number of extract as factors and extract quantity of Tas, five Fas, and eight Bas as the investigation index, respectively, the extract processes of Tas, Fas, and Bas from RRR were optimized. The optimized processes were verified by magnification test. Results: The optimum extract process of Tas and Fas was as follows five times of 75% ethanol, extracting five times by reflux, 30 min for each time. Using this process, the extraction rate for both original anthraquinones and Tas was about 90%, and Fas extraction rate was over 160%. The optimum extract process of Bas was as follows five times of 95% ethanol, extracting three times by reflux, 60 min for each time. Using this process, original anthraquinones extraction rate was close to 90%, and the one of Bas was over 80%. Conclusion: The optimized process is simple, stable, feasible, and repeatable, and can be used for the extraction of Tas, Fas, and Bas from RRR, respectively.