Abstract: On the basis of single factor test,the extraction process of polyphenol from filamentous fungi Lachnum singerianum YM-82 was researched by orthogonal test through the absorbance determined at the typical peak. The results showed that the optimal conditions are as follows:concentration of ethanol 80%,ratio of liquid to solid 50:1 and time 4 h. The antioxidant and free radical scavenging activities of polyphenol from L. singerianum YM-82 were evaluated using hydroxyal radical,superoxide anion radical and 1,1-diphenyl-2-picrylhydrazyl(DPPH) in vitro model systems. The results showed that the polyphenol has strong antioxidant and free radical scavenging activities. The reducing power of the polyphenol of 21 μg/ml is stronger than that of 25 mg/ml VC. The clearance rate to DPPH· of the polyphenol is 33.08% at 24.7 μg/ml concentration,1.18 times of that of 30 mg/ml VC,and the clearance rate to hydroxyal radical of the polyphenol is 63.8% at 22 μg/ml concentration,significantly higher than that of 50 mg/ml VC system.

Key words: Lachnum singerianum, polyphenol, extraction, antioxidant activity