Study On Separation Technology Of Terpenoids And Flavonoids In Tussilago Farfara

Tussilago farfara, an important Chinese medicinal material has the virtue of Anti-inflammation, expelling cough, phlegm, preventing asthma and so on. It is included in “compendiu of material medica” and “Chinese pharmacopoeia”. And as raw material, Tussilago farfara has been applied in more than 1000 kinds of Chinese medicine such as cold take pills and tablets of cough and asthma, etc. phytochemistry studies indicated that the active constituents of Tussilago farfara were terpenoids and flavonoids such as Tussilagone, tussilagolactone etc. Among them, Tussilagone has the effect of elevating blood pressure; tussilagolactone and farfaratine have the ability of inhibiting platelet aggregation, while the flavonoids of Tussilago farfara exhibit significant antioxidant effect and was widely used in Chinese medicine and health products to remove cough and asthma. In this paper, methods of separation and purification of active constituents from the Tussilago farfara were established by the means of High Speed Counter-Current Chromatography and the new material of silica based cross linking chitosan grafted with 4,4,-dihydroxychalcone(D-chitosan@Si).High Speed Counter-Current Chromatography was established to separate and purity terpenoids, such as Tussilagone from Flos Farfarae.The distribution coefficient of the main constitutes of petroleum ether extracts in different solvent were detected by HPLC. And constituent parameters of HSCCC were optimized. One-dimensional HSCCC separation was carried out by positive elution and squeeze elution under conditions as follows: the solvent system was n-hexane: n-butyl alcohol: acetonitrile(10:3:6), the temperature was 25 ℃,the rotational speed was 850 rpm/min and the flow rate was 1.5 m L/min. Off-line two-dimensional HSCCC separation was conducted with solvent system n-hexane: ethyl acetate: methanol : water(8:1:6:3), 25 ℃, rotational speed of 1000 rpm/min and flow rate of 1.5m L/min. Finally, tussilagone was obtained directionally, and 7β-(3-ethyl–ciscroto-noyloxy)-14-(2-methylbutyryloxy)-notonipetral-actone and 2,2-dimethyl-6-acetylchromanone were obtained together. The purity of them have reached more than 90%.A silica based cross linking chitosan grafted with 4,4’-dihydroxychalcone(DChitosan@Si)was prepared by taking advantage of the merits of chitosan and silica gel. Quercetin was chosen as the adsorption sample, the factors influencing the adsorption effect of D-Chitosan@Si were studied, such as initial concentration of the sample, p H, adsorption time and temperature. And the results showed that the adsorption process of D-chitosan@Si for Quercetin was an endothermic process. After that, the Langmuir adsorption isotherm model was fitted, and the results showed that the correlation coefficient was 0.995. And the adsorption behavior was monolayer adsorption. The adsorption behavior of Quercetin on D-chitosan@Si can be better described by secondary adsorption kinetics equation, the adsorption process may be controlled by multiple steps. D-Chitosan@Si showed higher selectivity for Quercetin in the competition adsorption between Rutin and Quercetin, and the selectivity coefficient reached 4.85. Compared with Chitosan@Si and Silica gel, the adsorption capacity of D-Chitosan@Si reached 17.49 mg/g, which was 4.6 times of Chitosan@Si and 11.2 times of Silica gel. And D-Chitosan@Si was used to separate and purify the flavonoids of Tussilago farfara. The crude extract of Tussilago farfara was adsorped and eluted in the optimized condition that : the sample concentration was 5 mg/m L, the p H value was 4 and the velocity was 1 BV/h, the eluent was 70% ethyl alcohol and velocity of 1.5 BV/h. The purity of total flaconoids can reach 85.6% as the crude extract was 18.9. It indicated an ideal selective separation effect.