2007-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/692567摘要：相思樹樹皮乙醇抽出物各可溶部中，以乙酸乙酯可溶部之抗氧化活性最佳，其能力與已知之抗氧化劑兒茶素相當。因此，乃利用矽膠管柱層析與高效能液相層析等技術分離及純化乙酸乙酯可溶部中EA12、EA13、EA17、EA18及EA19等5個次分離部，再以核磁共振儀及質譜儀等鑑定結構，共分離鑑定出11種酚類化合物，其中，包括：3,4-Dihydroxybenzoic acid、3-Hydroxy-4-methoxybenzoic acid、3,4-Dihydroxybenzoic acid ethyl ester以及 4-Hydroxy-3-methoxybenzoic acid 4種主要抗氧化物，其DPPH自由基捕捉能力依序為3,4-Dihydroxybenzoic acid = 3,4-Dihydroxybenzoic acid ethyl ester > 4-Hydroxy-3-methoxybenzoic acid > 3-Hydroxy-4-methoxybenzoic acid。<br> Abstract: The ethanolic extracts from the bark of Acacia confusa exhibit a strong antioxidant activity. Among all the fractions from ethanolic extracts of bark, the EtOAc soluble fraction shows the best antioxidant performance, with a free radical scavenging activity similar to that of (+)-catechin, which is a well-known antioxidant compound. Furthermore, following by column chromatography (CC) and high performance liquid chromatography (HPLC), eleven pure phenolic compounds, including four major antioxidant　compounds 3,4-dihydroxy -benzoic acid, 3-hydroxy-4-methoxybenzoic acid, 3,4-dihydroxybenzoic acid ethyl ester, and 4-hydroxy-3-methoxybenzoic acid, were isolated and identified from the five subfractions of EtOAc soluble fraction. Their scavenging activity of DPPH free radical decreased in the following order: 3,4-dihydroxybenzoic acid = 3,4-dihydroxybenzoic acid ethyl ester > 4-hydroxy-3-methoxybenzoic acid > 3-hydroxy-4-methoxybenzoic acid.相思樹抗氧化活性樹皮抽出成分酚類化合物Acacia confusaAntioxidant activityBarkExtractPhenolic compounds