Study On Secondary Metabolites And In Vitro Antioxidant Activity Of Cortinarius Caerulescens(Schaeff.) Fr.

In this study,the fruit bodies of Cortinarius caerulescens（Schaeff.）Fr.were used as experimental material,and the mathanol extracts were obtained by microwave-assisted extraction.The resulting crude reside was partitioned successively to yield three soluble extracts in petroleum ether,ethyl acetate,n-butanol and raffinate aqueous phase.DPPH radical-scavenging assay guided column chromatography techniques,including silica gel 60,Sephadex LH-20,reversed-phase ODS,and TLC（thin-layer chromatography）were used to isolated the active compounds.Chemical structures were identified on the basis of mass spectmroetry（HR-ESI-MS）and nuclear magneticresonance spectroscopy(¹H-NMR,¹³C-NMR)along with comparison with literature data.Finally,the result of antioxidant activity of pure compounds was evaluated.The results are as follows:（1）The antioxidant activity of ethyl acetate fraction was higher than the other fractions from methanol extracts.（2）The 18 isolated compounds from ethyl acetate fractions were identified as:（1）quinizarin;（2）emodin;（3）citreorosein;（4）emodin 1-O-methyl ether;（5）laccaic acid D;（6）endocrocin;（7）questinol;（8）citreorosein 6,8-dimethyl ether;（9）physcion;（10）SEK 15b;（11）cassiamin B;（12）endothianin;（13）（3S,3’S,P）-anhydrophlegmacin-9,10-quinone8’-O-methyl ether;（14）rufoolivacin C;（15）rufoolivacin A;（16）dirufoolivacin;（17）sinapiquinone;and（18）8-O-methylbostrycoidin on the basis of spectrum techniques along with comparison with literature data.Compounds 1-5,7,10-12,18 were first isolated from Cortinarius,and all the compounds were identified here for the first time in C.caerulescens.（3）Antioxidant activity tracing of 18 compounds was found compounds 16,15and 14 exhibited potent DPPH radical-scavenging activity with IC₅₀（Half Maximal Inhibitory Concentration）value of 2.77,7.50 and 8.63μg/ml,respectively.In summary,the antioxidant secondary metabolites of the C.caerulescens friut bodies were studied and 18 compounds were isolated which showed different degrees of antioxidant activity.And this study provides a theoretical basis for developing new antioxidant medicine and foods to prevent human neurodegenerative disease.