Abstract: In this study,total flavonoids of Penthorum chinense Purse were extracted by ethanol.The ethanol extract (EF) was further divided into ethyl acetate extraction phase (AF),n-butanol extraction phase (BF) and water extraction phase (WF) by fractional extraction.Among them,the content of total flavonoids existed in AF was 133.36 mg/g,higher than 50% of the total flavonoids content.AF exhibited the strongest antioxidant activities in chelating ferrous ion ability, DPPH free radical scavenging,hydroxyl radical scavenging and superoxide anion scavenging tests,with IC₅₀ values of 0.076,0.209,0.038 and 0.593 mg/mL,respectively.In addition,AF also possessed the highest antimicrobial activity against Staphyloccocus aureus and Pseudomonas aeruginosa, with the minimum inhibition concentration (MIC) of 0.075 mg/mL.

Key words: Penthorum chinense Purse, total flavonoids, fractional extraction, antioxidant activity, antibacterial activity