Chemical constituents comparison of Codonopsis tangshen, Codonopsis pilosula var. modesta and Codonopsis pilosula

Dang-shen, radix Codonopsis is one of the best-known traditional Chinese medicines and is used mainly as a tonic agent. Nine commercial products belong to three species of Codonopsis genus, Codonopsis tangshen, Codonopsis pilosula var. modesta and a cultivated species of Codonopsis pilosula, which were purchased from drug stores in Taipei and Taichung, Taiwan. To determine the chemical differences between samples of Dang-shen, a method combining solvent partition and HPLC-UV was used. An enriched fraction of n-butanol was obtained, after partition. Then, the chemical profile was determined using a C18 reversed column chromatography in a gradient solvent system with 10-40% acetonitrile in 0.1% formic acid, for 60min. A comparison of the constituents in the nine commercial products of Dang-shen showed that compounds codonopyrrolidum A, B and codonoside A only exist in C. tangshen, but not in C. pilosula var. modesta and C. pilosula. A predominate compound, codonopyrrolidum A, can be used to distinguish the herbs, C. tangshen from C. pilosula var. modesta and C. pilosula. Low secondary metabolite content was found in the cultivated species of C. pilosula.