Résumé
AIM To investigate the correlations between antioxidant activities and contents of total flavonoids and total phenols of chloroform,ethyl acetate,n-butanol and ethanol extracts from Nervilia fordii (Hance) Schltr..METHODS The contents of total flavonoids and total phenols in four extracts from N.fordii were determined by AlCl3-HAc-NaAc coloration method and Folin-Ciocalteu colorimetric method,respectively.The antioxidant activities of extracts were evaluated by determining scavenging activities of DPPH radical,hydroxyl radical and ABTS radical,together with reducing power.Then the correlations between antioxidant activities and contents of two constituents were analyzed by SPSS17.0 software.RESULTS The antioxidant activities of four extracts from N.fordii all showed dose-effect relationships,that of ethyl acetate extract was the strongest,while that of ethanol extract was the weakest.They had some correlations with the content of total flavonoids (0.604 ＜ r ＜ 0.638) and significant correlations with the content of total phenols (r ＞ 0.977).CONCLUSION Ethyl acetate extract from N.fordii can be used for the development of natural antioxidants,and the content of total phenols is the main factor to influence its antioxidant activity.