摘要Objective:To determine the extraction suitable conditions of total phenolic content(TPC) by heat-reflux system, antioxidant activities andHPLC characterization of the aqueous-ethanolic extracts ofJatropha dioica (J. dioica)(Dragon’s blood),Flourensia cernua (F. cernua)(Tar bush), Eucalyptus camaldulensis(E. camaldulensis)(Eucalyptus) and Turnera diffusa (T. diffusa) (Damiana).Methods:TPC was evaluated by the well-known colorimetric assay usingFolin-Ciocalteu reagent.The antioxidant activities were assayed by three methods based on scavenging ofDPPH,ABTS and by lipid oxidation inhibition.The chemical composition of the extracts obtained was subject toHPLC analysis.Results:TPC in the plant extracts ranged from2.3 to 14.12 mg gallic acid equivalents/g for J. dioica and E. camaldulensis, respectively.The plant extracts ofF. cernua,E. camaldulensis andT. diffusa showed similar strong antioxidant activities on scavenging ofDPPH and lipid oxidation inhibition.In contrast,J. dioica extracts had lowest potential antioxidant in three assays used.HPLC assay showed the presence of several phenolic compounds in the extracts used.Conclusions:The results obtained suggest thatF. cernua, E. camaldulensis andT. diffusa are potential sources to obtain bioactive phenolic compounds with high antioxidant properties which can be used in the factories as antioxidant agents or for treatments in diseases.