本實驗的目的在進行石蓮花（Graptopetalum paraguayense E. Walther)酒精萃取物(GE)抗氧化能力的 研究。實驗中利用超音波萃取技術進行石蓮花的萃取，再以總多酚、總類黃酮、DPPH自由基清除率、還 原力、亞鐵離子螯合等非酵素系統及超氧陰離子、微脂粒氧化作用之抑制等酵素系統方法進行石蓮花萃取 物抗氧化能力的評估。研究結果顯示:石蓮花酒精萃取物的總多酚和總類黃酮含量分別為466.7±2.6 GAE及 169.3±2.5RE mg/g ； DPPH 自由基與 ABTS+ 50%清除濃度(IC5。)分別為 68.1±0.8 和 181.7±3.2 μg/mL ；超氧陰 離子清除能力和抑制脂質過氧化能力IC50分別為38.6±0.4和57.7±8.4μg/mL。綜合以上結果，石蓮花酒精萃取物具有良好的抗氧化能力。

The aims of this study were to evaluate the antioxidative activity of ethanolic extracts of Graptopetalum paraguayense E. Walther. For non-enzymatic antioxidants, several methods were used, they were the total polyphenol, total flavonoid, a,a-diphenyl-p-picrylhydrazyl (DPPH) radical scavenging assay, reducing power, ferrous ion chelation. Enzymatic antioxidants of extracts were assayed by superoxide radical scavenging and inhibition of lipid peroxidation in a liposome model system. The results show that the total phenolic content and total flavonoid content of ethanolic extracts of Graptopetalum paraguayense (GE) were 466.7士2.6 GAE and 169.3士2.5 RE mg/g, respectively. The 50% inhibition concentration (IC5q) of DPPH and ABTS radical+ scavenging of GE were 68.1士0.8 and 181.7 士3.2 (ig/mL, respectively. The IC5q of superoxide radical scavenging and lipid peroxidation inhibition of GE were 38.6士0.4 and 57.7士8.4 ig/mL, respectively. The results showed that ethanolic extracts of Graptopetalum paraguayense E. Walther have strong antioxidative activity.