ABSTRACT
<p><b>OBJECTIVE</b>To explore the optimum extraction and purification condition of the total saponins in the root of Panax japonicus (RPJ), and establish its quality control methods.</p><p><b>METHOD</b>Designed L16 (4(5)) orthogonal test with the extraction rate of total saponins as index, to determine the rational extraction process, and the techniques of water-saturated n-butanol extraction and acetone precipitation were applied to purify the alcohol extract of RPJ. Total saponins were detected by spectrophotometry and its triterpenoidal sapogenin oleanolic acid detected by HPLC.</p><p><b>RESULT</b>The optimum conditions of total saponins from RPJ was as follows: the material was pulverized, dipped in 60% ethanol aqueous solution as extract solvent at 10 times of volume, and refluxed 3 times for 3 h each time. Extractant of water-saturated n-butanol with extraction times of 3 and precipitant of acetone with precipitation amount of 4-5 times were included in the purification process, which would obtain the quality products. The content of total saponins could reach to 83.48%, and oleanolic acid to 38.30%.</p><p><b>CONCLUSION</b>The optimized preparative technology is stable, convenient and practical. The extract rate of RPJ was high and steady with this technology, which provided new evidence for industrializing production of the plant and developing new drug.</p>