Optimization of purification process of total phenolic acid from Geum japonicum var.chinense by macroporous resin and investigation of its quality standard
Objective:The purification process of total phenolic acid from Geum japonicum var.chinense using macroporous adsorption resin was optimized.The fingerprint of total phenolic acid fraction from Geum japonicum var.chinense was established accordingly.The contents of gemin A,ethyl gallate,ellagic acid and total phenolic acid were determined using the developed method.Methods:Single factor experiment was used to select the type of macroporous resin,adsorption conditions,impurity removal conditions and desorption conditions based on the adsorption rate,resolution rate of total phenolic acid and content,transfer rate of total phenolic acid.HPLC and ultraviolet-visible spectrophotometry were used to establish a quality control method for the determination of gemin A,ethyl gallate,ellagic acid and total phenolic acid content,and the fingerprint analysis of total phenolic acid fraction.Results:HPD-400 macroporous resin was selected,method was:sample solution concentration of 8 mg·mL-1,adsorption flow rate of 2 BV·h-1,diameter-height ratio of 1∶8,sample liquid volume of 3 BV,4 BV10%ethanol to wipe off impurity with a flow rate of 3 BV·h-1,5 BV 50%ethanol to elute with 4 BV·h-1.The average content of total phenolic acid obtained by the 3-batch verification test was 67.75%(RSD3.02%),and the average transfer rate was 74.53%(RSD 1.20%).A total of 18 common peaks were established in the fingerprint,in which 6 peaks were identified,namely dimerized gemin B,gemin G,gemin A,tellimagrandin Ⅱ,ethyl gallate,ellagic acid,and the similarities of 12 batches of total phenolic acid fraction were above 0.9 by comparing with the control fingerprint.The methodology for the determination of gemin A,ethyl gallate,ellagic acid and total phenolic acid content met the requirements.The three components had good linear relationship in their respective ranges(R2≥0.997),and the average dosing recovery rate was 93.00%~103.53%,RSD 1.92%~3.87%.The content ranges of 12 batches of samples were 5.35%~15.25%,0.12%~0.62%,1.84%~6.27%.In terms of gallic acid,the linear range of total phenolic acid was good(R2 = 0.995),the average dosing recovery rate was 95.30%,RSD was1.40%,and the total phenolic acid content of 12 batches of samples ranged 53.65%~73.16%.Conclusion:Purification process is stable and reliable to be used for the enrichment of total phenolic acid fraction of Geum japonicum var.chinense.The fingerprints and determination method of ellagic acid content are stable and reliable to be used for the quality control of total phenolic acid fraction of Geum japonicum var.chinense.