杜仲叶清除DPPH自由基动力学特性及抗氧化活性成分筛选

目的 研究杜仲叶抗氧化清除1,1-二苯基-2-苦肼基(DPPH)自由基的动力学特性,筛选其抗氧化活性成分,建立与抗氧化活性相关的质量控制方法.方法 比较不同杜仲叶样品浓度、反应温度和反应时间对DPPH自由基清除率的影响,测定杜仲叶清除DPPH自由基活性的半数清除率(IC50).采用DPPH-HPLC法测定杜仲叶与DPP...

DPPH Kinetic Characteristics and Identification of Antioxidant Compounds in Eucommia ulmoides Leaves

OBJECTIVE To study the dynamic characteristics of DPPH scavenging activity of Eucommia ulmoides leaves, and identify the antioxidant active compounds. METHODS The influence of different concentrations of E. ulmoides leaves, reaction temperature and reaction time were compared. IC₅₀ of DPPH free radical scavenging rate was determined. DPPH-HPLC was used to analyze the content changes of the main compounds in E. ulmoides leaves before and after reaction with DPPH. RESULTS The concentrations of E. ulmoides leaves, reaction temperature and reaction time could affect DPPH free radical scavenging rate. The DPPH free radical scavenging rate of E. ulmoides leaves increased with the raise of concentration E. ulmoides leaves, reaction temperature and reaction time correspondingly. The IC₅₀ of DPPH free radical scavenging rate was 0.509 mg·mL^-1. Compared with the contents before reaction with DPPH, the contents of aucubin, geniposidic acid in E. ulmoides leaves decreased little; while the contents of chlorogenic acid, rutin, isoquercitrin and astragalin decreased significantly. It suggested that chlorogenic acid, rutin, isoquercitrin and astragalin might be main antioxidant compounds in E. ulmoides leaves. CONCLUSION The dynamic characteristics of DPPH free radical scaveging activity of E. ulmoides leaves are preliminarily known. The antioxidant compounds in Eucommia ulmoides leaves were identified, which could provide reference for quality control of E. ulmoides leaves related to antioxidant activity.