Study On The Chemical Constituents And Bioactivity Of Cynara Scolymus

Artichoke (Cynara scolymus) belonging to the family Asteraceae, is a high-nutrition vegetables. It was rich in artichokethin, asparagine and anthoxanthin, which can strengthen the function of the liver, and prevent hardening of artery and anti-HIV.In this dissertation, the leaves of Artichoke were subjected as raw material to the extraction and purification of polyphenol, and those process were optimized through systematical studies with indicator of artichoke polyphenol content. Additionally, antioxidant and antibacterial activities of artichoke polyphenol were investigated in different tests. Based on the activities screening result, the secondary metabolites of aerial parts from C scolymus were studied using the phytochemistry menthods, such as C18-MPLC, HPLC, Prep-HPLC and so on. Finally, six compounds were isolated and identified. For effective and comprehensive utilization of the artichoke resource, the theoretical basis research of artichoke for industrialization is important. The research results are as follows:1. The experiment of ultrasonic extract menthod to determine the optimal processing condition of leaning artichoke polyphenol were studied. The optimum parameter:solvent of 70% ethanol, liquid-solid ration 1:20, ultrasonic irradiation time 50min. The contents of polyphenol reached 88.23 mg/mL when artichoke leaves extracted under this conditions. In addition, screening the characteristics of artichokes polyphenols with nine resin, resulted NKA-2 was the best. The purity of artichoke polyphenols can be up to 135.3 mg/mL.2. The antioxidant and antibacterial activities of the crude polyphenol and purified polyphenol were evaluated in vitro. The result indicated that, the purified polyphenol on DPPH radical, ABTS+ radical antioxidant capacity is stronger than crude polyphenol, while their IC50 values were 32.3 μg/mL and 107.98 μg/mL, repectively. The total antioxidant capability of purified polyphenol at 80 μg/mL was equal to that of crude polyphenol at 321 μg/mL. It was found that the purified polyphenol and crude polyphenol have antibacterial effects on six strains of Staphylococcus. aureus、Escherichiacoil、Bacillus、Pseudomonas.aeruginosa、Lactobacillaceae and Monilia albican, and the antibacterial activities of purified polyphenol is superior to the crude polyphenol. Their MIC values of purified polyphenol is 10, 8, 12, 13, 12, and 13 mg/mL, crude polyphenol is 25,22.5,20,32.5,27.5, and 30 mg/mL. However the purified polyphenol and crude polyphenol couldn’t inhibit the growth of Klebsialla.Pneuniae in the range of test concentration.3. The research of chemical constituents of C. scolymus. By means of column chromatography such as normal-phase silica gel column, alumina colu-mn, LH-20, macroporous resin column, the leaves of C. scolymus cultivated in Yunnan Province were extraxted and isolated. Six compounds were identified f-rom aqueous fraction of cultivated C. scolymus by modern spectroscopic techn-iques such as NMR, ESI-MS and UV methods. The structures were elucidated as (+)-pinoresinol-4-O-β-D-glucopyranoside (1), syringaresinol-4-O-β-D-glucopyr anoside (2), syringaresinol (3),3-hydroxy-2-naphthalene carboxylic acid (4), cy-naropicrin (5),8-deoxy-11,13-dihydroxygrosheimin (6) were isolated, of which compounds 1,2,5 and 6 were reported from C. scolymus, and the compound 4 is a new compounds.