本研究目的為評估臺灣棒(Zelkova serrata (Thunb.) Makino)枝條精油和各種溶劑 抽出物之抗氧化活性，由試驗結果得知，臺灣櫸枝條丙酮抽出物清除DPPH自由基能力、
總抗氧化能力和還原力均較其它溶劑抽出物或精油為佳；至於總酚類及總黃酮類化合物含 量皆以丙酮抽出物最高。續評估丙酮抽出物之正己烷、乙酸乙酯、正丁醇及水4個可溶部 之各項抗氧化活性，試驗結果得知，水可溶部清除DPPH自由基和還原力之效果較其它可 溶部為佳，乙酸乙酯可溶部的總抗氧化能力最佳；至於各可溶部之總酚類和總黃酮類化合 物含量，分別以水和正丁醇2個可溶部的含量最高。本研究結果顯示，臺灣櫸枝條丙酮抽 出物極具潛力開發為抗氧化劑，非常值得進一步深入研究。

The aim of this study was to evaluate the antioxidant activities of essential oil and various solvent-soluble extracts from twigs of Zelkova serrata. Results demonstrated that the acetone extract possessed the great free radical scavenging activities, trolox equivalent antioxidant capacity (TEAC) and reducing power more than other solvent-soluble extracts and essential oil from Z. serrata twig. In addition, the twig acetone extract contained the highest level of total phenolic content (TPC) and total flavonoid content (TFC). The antioxidant activities of 4 soluble fractions from twig acetone extract were further examined. Results showed that the water soluble fraction had an excellent free radical scavenging activities and reducing power more than other soluble fractions. However, the ethyl acetate soluble fraction had the greatest TEAC. In addition, TPC and TFC of 4 soluble fractions were also examined. Results showed that the TPC and TFC of both water and BuOH soluble fractions were at the highest level. Based on the results, it revealed that the acetone extract of twigs from Z. serrata could be used as a potential source for antioxidants and is worth for further investigation.