Determination of Contents of Total Saponins and Monomer Saponins in Panax ginseng by Microwave-Assisted Extractiion Method

Single factor and orthogonal array designs were applied to optimize the conditions for microwave-assisted extraction of ginsenosides, and the determination of eight main monomer saponins and total saponins in Panax ginsengextracts was performed by high performance liquid chromatography and spectrophotometry to investigate the influence of different extraction conditions on the ginsenoside contents and composition in Panax ginseng extracts. The results showed that 1) the optimum extraction conditions for total saponins were determined as follows: microwave power, 600 W; extraction temperature, 45 ℃; extraction time, 5 min; the ratio of material to solvent, 1:20; and extraction number, 3; 2) the optimum extraction conditions for saponin monomers(leading to an extraction yield of 0.98%) were 300 W, 35 ℃, 15 min, a material-to-solvent of 1∶25, and three extraction cycles; 3) under the optimum conditions, with 80% aqueous methanol as the extraction solvent, the yield of total saponins was 6.02%, while the total yield of eight ginsenoside monomers was 0.43%compared to 0.71% with water-saturated butanol as the extraction solvent. In summary, ginseng quality evaluation and process optimization results were influenced by different extraction methods, extraction conditions and evaluation indexes.