| Eurotium cristatum are stablely natural probiotics in Fu-brick tea,commonly known as "golden flower". Due to the presence of E. cristatum, making the color, smell and taste of Fu-brick tea to be different from other teas.What’s more,because of the existence of E. cristatum, making Fu-brick tea have antioxidant, promoting digestion, lipid-lowering, antibacterial, anti-cancer and other health effects. Therefore, more and more people study on the fanctional effects of E. cristatum.In this article,I want to fermentate rice by E. cristatum and study the chemical compositions、the antioxidant activity of different extracts in vitro and the regulation and control of the fermentation of E. cristatum by different drugs and bacterias.After the solid fermentation,achieving four extracts from E. Cristatum by liquid-liquid extraction:the petroleum ether extract (ECPE)4.0g, the ethyl acetate extract (ECEA)12g, the n-butanol extract (ECBU)9.0g and the water extract (ECWA)245g. Analyse the chemical compositions of the four extracts by HPLC and study the antioxidant activity of different extracts in vitro. The results:System separation methods, the use of liquid-liquid extraction、vacuum column chromatography on silica gel、Sephadex LH-20column chromatography、HPLC and other means. Eleven known compounds were isolated from rice ethyl acetate extract of the fermentation product. Their structures were determined by analysis of the spectroscopic data. The12compounds are as follows:(1)7-Hydroxyemodin,(2) Emodin,(3) Physciondianthrone,(4) Physcion,(5) Palatinol C,(6) Variecolorin O,(7) Neoechinulin A,(8) Citreorosein,(9)2,co-dihydroxyemodin,(10) echinulin,(11) Endocrocin.The results of antioxidant tests showed:The petroleum ether extract from E. Cristatum showed significant DPPH and ABTS+radical scavenging activity,with IC50values of0.078and0.083g·L-1, respectively (the positive control Vc showed IC50values of0.032and0.024g·L-1, respectively. The ethyl acetate extract exhibited modest radical scavenging activity against DPPH and ABTS+radicals, with IC50values of0.212and0.126g·L-1, whereas the n-butanol extract did not display noticeable in vitro activity against above-mentioned radicals. The results of FRAP test showed that the order of antioxidant capacity is: ECPE>ECEA>ECBU>total extract>ECWA. Whereas the total extract,ECBU and ECWA did not display noticeable antioxidant activity in all three assays.Both of the compound6and7showed the antioxidant activity. Compound6showed significant DPPH and ABTS+radical scavenging activity,with IC50values of0.041and0.099g·L-1, respectively (the positive control Vc showed IC50values of0.027and0.023g·L-1, respectively). The antioxidant capacity of these two compounds showed a dose-dependent. Whereas, all of the compound1、2、5、8and10did not display noticeable in vitro activity against above-mentioned radicals.Using the mixed fermentation technology, the E.cristatum was cultured with different drugs and bacterias. The ethyl acetate extract from E. cristatum was analysised by HPLC. The results showed: All of Nicotinamide, Vorinostat and5-Azacytidine showed a negative effect on the metabolic regulation of E.cristatum. And Vc did not show any effect on E.cristatum; The Staphyloccocus aureus exhibited significant positive effect on the metabolic regulation of E.cristatum, and many new compounds were found in the mixed fermentation. All of the Streptococcus pneumonia, Escherichia coli, Bacillus subtilis, Enterococcus faecalis and Pseudomonas aeruginosa exhibited modest effect on the metabolic regulation of E.cristatum. |
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