Determination of individual ginsenoside and malonyl-ginsenoside in different commercial ginseng products

a HPLC method for determining the contents of individual ginsenoside and malonyl-ginsenoside in different commercial ginseng products was established, to provide data for the quality evaluation. Method: The ginseng extract solution was separated and analyzed(20 μL aliquots) by using a Prosphere C18 300 A column(250 mm×4.6 mm, 5 μm) with a Prosphere C18 guard column. The mobile phase consisted of solvent A(acetonitrile) and solvent B(phosphate buffer solution). Solvent B was prepared by dissolving 3.50 g KH2PO4 in 2500 mLwater and adjusting the pH to 5.81 with a concentrated solution of K2HPO4(35 g/100 mL). For the simultaneous separation of neutral ginsenosides and malonly-ginsenosides, the following gradient procedure was used: 0～50 min, 20%～33% A; 50～54 min, 33%～100% A; 54～66 min, 100% A; 66～67 min, 100%～20% A; 67～80 min, 20% A. The flow rate was kept constant at 1.0 mL/min. The absorbance was measured at a wavelength of 203 nm. Results: ginsenoside content in Chinese ginseng tea is higher than that in Korea ginseng tea. Three ginseng extracts do not contain any ginsenoside, the Korea product, and the two other Chinese products. It showed a range of ginsenoside content in Korea red ginseng, which is very near to that in Chinese red ginseng. Among the 8 American ginseng samples, ginsenoside content in root hair is higher than those in main roots; however no direct relationship between ginsenoside content in roots and size of roots can be found. Ginsenoside profile in san qi flower is different from that in main root. The main ginsenoside in San Qi main root are Rb1, Rg1 and Rd while those in San qi flower are Rb1, Rb2, Rc and Rd. Ginseng cosmetics contain less ginsenosides( 0.5%), which was lower than those in other ginseng products, and no ginsenoside Re and Rg1 are detected in them. Conclusions: ginsenoside and malonyl-ginsenoside were separ-ated well under this HPLC condition, which was rapid, precise and convenient. It could also be a good method for evaluating the quality of ginseng and its products.