Quality evaluation of medicinally-used Codonopsis species and Codonopsis Radix based on the contents of pyrrolidine alkaloids, phenylpropanoid and polyacetylenes

A comparative study of 56 specimens of three medicinally-used Codonopsis taxa collected from China and 54 commercial samples of Codonopsis Radix available in Chinese, Japanese and Korean markets was carried out by quantitative analysis of seven major components: codonopyrrolidium B (1), codonopyrrolidium A (2), tangshenoside I (3), cordifolioidyne B (4), lobetyolinin (5), lobetyolin (6) and lobetyol (7). The quantitative results, based on a well-established HPLC-DAD method, indicated that the contents of these seven compounds varied considerably among the samples, not only inter-species but also intra-species. C. pilosula and C. pilosula var. modesta showed similar chemical compositions, while C. tangshen differed considerably from these two in chemical composition. The results of principal component analysis (PCA) indicated that two main groups were classified; one group mainly included C. pilosula, C. pilosula var. modesta and the commercial samples derived from these two taxa, while the other group was composed of C. tangshen and its derived commercial samples. Compound 1 was the main component in the roots of C. pilosula and C. pilosula var. modesta, while 3 and 2 had relatively high contents in the roots of C. tangshen. Therefore, 3, 2 and 1 could be chemical markers to differentiate C. tangshen from C. pilosula and C. pilosula var. modesta.