臺灣肖楠心材抗氧化成分之研究

Abstract

臺灣肖楠（Calocedrus macrolepis var. formosana）心材乙醇抽出物抗氧化試驗結果顯示乙醇抽出物具有良好之抗氧化活性，總酚類含量為187.1 mg of GAE/g，具有清除DPPH自由基與抑制β-胡蘿蔔素氧化脫色的活性，同時亦具有良好的還原力與總抗氧化能力。各可溶部中，以乙酸乙酯可溶部之總酚類含量最高（238.5 mg of GAE/g），可有效清除DPPH自由基，還原能力、總抗氧化能力及抑制β-胡蘿蔔素氧化脫色等，其效果更優於乙醇抽出物。 續以管柱層析法將乙酸乙酯可溶部分成11個次分離部，測定清除DPPH自由基能力與還原力後，確定E5次分離部之抗氧化活性最佳，此外，E4、E6與E7次分離部亦具有良好之抗氧化能力。由活性次分離部中，進一步分離出6種木酚素化合物，其中，1-Propanoxy-4-(4'-hydroxy-3'-methoxy phenyl)-7-methoxy-1,3,3a,4,9,9a- hexahydronaphtho [2,3c] furan-6-ol、(-)-Haplomyrfolin與

Results of antioxidant activity assays show that the ethanolic extract of Calocedrus macrolepis var. formosana heartwood has great antioxidant activities, and the total phenolic contents of the extract was 187.1 mg of GAE/g. Therefore, it also exhibited good effectiveness in scavenging DPPH free radicals, inhibition of β-carotene bleaching, reducing power and total antioxidant activity. Among three fractions, ethyl acetate-soluble fraction possess the highest amount of total phenolic content (238.5 mg of GAE/g) and demonstrated the great capacity of scavenging DPPH free redicals, reducing power, total antioxidant activity and inhibition of β-carotene bleaching. Ethyl acetate-soluble fraction were then separated into 11 subfractions. which were assayed by DPPH free radical scavenging assay and reducing power.Results revealed that subfraction E5 possessed best antioxidant activities. Moreover, subfraction E4, E6 and E7 also have good antioxidant activities. Six compounds were isolated from ethyl acetate-soluble fraction, including (-)-haplomyrfolin, 1- propanoxy-4-(4'-hydroxy- 3'-methoxy phenyl)-7-methoxy-1,3,3a,4,9,9a-hexahydro-naphtho [2,3c] furan-6-ol, matairesinol, (7E)-4’,5-dihydroxy-3,3’,4-trimethoxylign-7-en-9,9’-olide,