Optimization of the extraction and purification of Corydalis yanhusuo W.T. Wang based on the Q-marker uniform design method

Abstract

<i>Corydalis yanhusuo W.T. Wang</i> alkaloids are mainly divided into three categories: protoberberine, prototropine and aporphine alkaloids. Therefore, we have taken into account these three alkaloid contents when extracting and purifying crude drugs, which is essential for the quality control of <i>C. yanhusuo</i> and its derivative products. Herein, we investigated the feasibility of the Q-marker uniform design method in the optimization of the extraction and purification of <i>C. yanhusuo</i>. In this study, Q-marker-based comprehensive scoring (CS) and uniform design methods were used to optimize the extraction and purification of <i>C. yanhusuo</i>. The inspective factors included the solvent concentration, pH, liquid-solid ratio, extraction time and frequency. Then 8 Q-markers, the total alkaloid extraction and the extraction rate were considered as the evaluating indicators during the process. The results indicated that the optimal reflux extraction process of <i>C. yanhusuo</i> was as follows: a total amount of 20 times 70% ethanol (pH = 10 of diluted ammonia), heating and refluxing twice, and extracting each time for 60 min. The results of nine-resin screening exhibited that NKA-9 macroporous adsorption resin had the best separation and purification effect on 8 kinds of <i>C. yanhusuo</i> alkaloids with stronger enrichment. During the optimal enrichment process and elution conditions, the water-soluble impurities were washed off with 5 BV distilled water at a volume flow rate of 2 BV/h, and the elution solvent was 70% ethanol with an elution volume flow rate of 1.5 BV/h and an elution dosage of 12 BV. Additionally, the total alkaloids of the obtained product were over 50%, of which eight quality markers were (+)-corydaline 3.55%, tetrahydropalmatine 3.13%, coptisine 2.79%, palmatine hydrochloride 2.24%, dehydrocorydaline 13.11%, (R)-(+)-corypalmine 2.37%, protopine 2.71% and glaucine 14.03%. Our data demonstrated that the optimal extraction and purification process was stable and feasible, which was expected to provide an experimental basis and reference for the industrial production of <i>C. yanhusuo</i>.