[Metabolomic study of flower buds of Tussilago farfara in different development stages by GC-MS].

OBJECTIVE: Plant metabolomics combined with GC-MS was used to investigate metabolic fingerprinting of Tussilago farfara at different growth stages. METHOD: Dried Samples were extracted by two-phase solvent system to obtain polar and nonpolar parts, which were subjected to GC-MS analysis. Metabolites were identified by NIST data base search and comparison with the authentic standards. The data were introduced into SIMCA-P 11.0 software package for multivariate analysis after pretreatment. RESULT: Fifty-four metabolites were identified, including 35 polar metabolites and 19 nonpolar compounds. The score plot for PCA showed clear separation of the different development stages of flower buds of T. farfara, showing a trend of gradual change. Samples of October, November, December were in close proximity on the plot, indicating that the metabolome of these three periods was similar, samples from September (early development) and March (after flowering) were far away, showing big chemical differences. Content comparison results of some representative metabolites reveals that, the content of proline, lysine and linoleic acid increased gradually to the highest in the medium term, but sharply decreased to the lowest after flowering; the content of malic acid and citric acid were the lowest in the medium term; sucrose content decreased gradually, and then reached the lowest level after blooming. CONCLUSION: It is obvious that metabolites of the early development and flowering stage were quite different with those of the traditional harvest time, suggesting that they can not be used as traditional medicine. This study will provide a research basis for harvest time determination and bioactive compounds of T. farfara.

Metabolomic profiling of the flower bud and rachis of Tussilago farfara with antitussive and expectorant effects on mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Flower bud of Tussilago farfara L. is widely used for the treatment of cough, bronchitis and asthmatic disorders in the Traditional Chinese Medicine. However, due to the increasing demands, adulteration with rachis is frequently encountered in the marketplace. No report demonstrated the chemical and pharmacological differences between flower bud and rachis before. MATERIALS AND METHODS: The water extracts were orally administrated to mice. Ammonia induced mice coughing model was used to evaluate the antitussive activity. The expectorant activity was evaluated by volume of phenol red in mice's tracheas. Metabolites were identified directly from the crude extracts through 1D- and 2D-NMR spectra. A metabolic profiling carried out by (1)H NMR spectroscopy and multivariate data analysis was applied to crude extracts from flower bud and rachis. RESULTS: Flower bud significantly lengthened the latent period of cough, decreased cough frequency caused by ammonia and enhanced tracheal phenol red output in expectorant evaluation. Principal component analysis (PCA) yielded good separation between flower bud and rachis, and corresponding loading plot showed that the phenolic compounds, organic acid, sugar, amino acid, terpene and sterol contributed to the discrimination. CONCLUSIONS: These findings provide pharmacological and chemical evidence that only flower bud can be used as the antitussive and expectorant herbal drug. The high concentration of chlorogenic acid, 3,5-dicaffeoylquinic acid, rutin in flower buds may be related with the antitussive and expectorant effects of Flos Farfara. To guarantee the clinical effect, rachis should be picked out before use.