Study On Antioxidant Activities And Antioxidative Compounds Of Four Species Of Ascomycetes

The antioxidant activities of four species of ascomycetes(Cordyceps sinensis,Cordyceps gunnii,Cordyceps militaris and Xylaria nigripes.) were evaluated by DPPH free radical scavenging activity,reducing power,ferrous ion chelating activity and the content of total phenolics.The results are as follows.(1)DPPH free radical scavenging activity There were no significant differences among the fruiting body of four ascomycetes (P＞0.05).But significant differences existed in different mycelia. DPPH scavenging capacity of the mycelia of Cordyceps sinensis and Cordyceps militaris was significantly higher than Xylaria nigripes (P＜0.05),but significantly lower than that of Cordyceps gunnii(P＜0.05).The mycelia of Cordyceps sinensis and Cordyceps militaris didn't show significant difference(P＜0.05).DPPH scavenging capacity of fruiting bodies of four ascomycetes were all significantly higher than their mycelia(P＜0.05).(2) Reducing power.Reducing power decreased in the order of C.gunnii(F)＞C.militaris(F)＞C.sinensis(F)＞C.gunnii(M)＞X.nigripes(F)＞C.sinensis(M)＞C.mili taris(M)＞X.nigripes(M). Reducing power of mycelia of four ascomycetes showed significant difference(P＜0.05).No significant differences existed between the fruiting bodies of Cordyceps gunnii and Cordyceps militaris(P＞0.05),but both had significant difference with Cordyceps sinensis and Xylaria nigripes(P＜0.05).(3) Chelating ability on ferrous ions Chelating ability of four ascomycetes decreased in the order of X.nigripes(F)＞C.militaris(F)＞C.gunnii(M)＞C.sinensis(F)＞X.nigripes(M)＞ C.militaris(M)＞C.sinensis(M)＞C.gunnii(F) at 500μg/mL.(4) The content of total phenolics.The content of total phenolics in the fruit bodies was significantly higher than the mycelia.The content of total phenol decreased in the order of C.gunnii(F)＞C.militaris(F)＞C.gunnii(M)＞C.sinensis(F)＞X.nigripes(F)＞C.sinensis(M)＞C.militaris(M)＞X.nigripes(M) and were 65.43,64.93,54.35,44.27,40.08,27.01,22.71,12.14μg/mg, respectively.(5) The relativity between total phenolics and DPPH scavenging ability and reducing power The relation of DPPH scavenging ability and reducing power IC₅₀ values and total phenolics was analysed.The result showed the relationship of total phenolis and DPPH scavenging ability and reducing power was positive correlation.Liquid-liquid extraction and Column Chromatography were pplied to separate antioxidative components in Cordyceps militaris.And seven crude component,named PE-1,PE-2,PE-3,PE-4,PE-5,EA-1 and EA-4,were got.Their activities were evaluated by qualitative or quatitative analysis.EA-1 and EA-4 showed the best antioxidant activity.DPPH free racical scavenging activity were 85.48%and 72.58%,respectively.