本研究利用薄層層析、管柱層析及高效能液相層析等技術,分離純化相思樹花抽出成分,並利用DPPH自由基清除、超氧自由基清除、脂質過氧化以及還原力等方法評估其抗氧化活性,且測定總酚類含量以及總黃酮類含量。所得到之抗氧化活性成分,則進一步運用質譜分析以及核磁共振光譜分析等技術鑑定化合物之結構。由相思樹花甲醇粗抽出物之二氯甲烷可溶部、正丁醇可溶部及水可溶部之抗氧化活性試驗結果顯示,正丁醇可溶部具有最好的抗氧化活性,除了脂質過氧化外,不論在DPPH自由基或超氧自由基清除能力以及還原能力,正丁醇可溶部皆有很好的效果,活性比原甲醇粗抽出物好,而且正丁醇可溶部之總酚類含量(263.2 mg GAE /g)最高,因此,續以管柱層析將正丁醇可溶部分離成15個次分離部。其中,Bu3、Bu4及Bu5次分離部具有很好的DPPH自由基清除能力,並含有很高的黃酮類含量,而又以Bu4次分離部之抗氧化活性最強且黃酮類含量最高。次分離部中共分離出6個黃酮類化合物,包括:Myricitrin、Quercitrin、Europetin-3-rhamnoside、Kaempferol-3-rhamnoside、Rhamnetin-3-glucoside及Rhamnetin-3-rhamnoside六個化合物,其中以 Myricitrin及Europetin-3-rhamnoside的抗氧化活性最好。而正丁醇可溶部水解後之乙酸乙酯可溶部具有很強的抗氧活性,其中所含的成分為Myricetin、Quercetin、Europetin以及Keampferol。此外,將相思樹花與市面上之花茶(洋甘菊、桂花、玫瑰及茉莉)的熱水抽出物進行抗氧化活性比較,結果顯示相思樹花之抗氧化能力與洋甘菊相同,並且優於茉莉。
In this study, thin layer chromatography (TLC), column chromatography (CC) and high performance liquid chromatography (HPLC) were employed to separate and purify the constituents of the methanolic extracts of Acacia confusa flowers. Furthermore, the antioxidant activities were evaluated by DPPH radical and superoxide radical scavenging assays, lipid peroxidation assay and reducing power assay. Total phenolic contents and total flavonoid contents were also evaluated. In addition, the chemical structure of active constituents from A. confusa flowers was identified by the analyses of mass spectroscopy and nucleus magnetic resonance spectroscopy (NMR), etc. Results demonstrated that among all soluble fractions (CH2Cl2, BuOH and Water) of methanolic extracts of A. confusa flowers, BuOH fraction has the best activities. Though the inhibition of lipid peroxidaiton of BuOH fraction is low, the DPPH radical and superoxide radical scavenging activities are the highest, even better than that of crude methanolic extracts. Total phenolic content of BuOH fraction (263.2 mg GAE /g) is also the highest. BuOH fraction was then separated into 15 subfractions which were tested by DPPH radical scavenging assay for antioxidant activity and their total flavonoid contents were also evaluated. Subfractions Bu3, Bu4 and Bu5 showed a strong antioxidant activity, especially subfraction Bu4, which also contains the most flavonoids. Six pure flavonoids, myricitrin, quercitrin, europetin-3-rhamnoside, kaempferol-3-rhamnoside, rhamnetin-3-glucoside and rhamnetin-3-rhamnoside were isolated from BuOH fraction of A. confusa flowers. Among them, myricitrin and europetin-3-rhamnoside are the best antioxidant compounds. The EA fraction hydrolyzed from BuOH fraction in which major constituents are myricetin, quercetin, europetin and keampferol has remarkable antioxidant activities. Furthermore, the antioxidant activities of hot water extracts from various flowers (A. confusa, Matricaria chamomilia, Osmanthus fragrans, Rose rugosa and Jasminum sambac) were also compared. Results obtained indicated that antioxidant activities of A. confusa flowers are comparable to M. chamomilia and better than J. sambac.
為了持續優化網站功能與使用者體驗,本網站將Cookies分析技術用於網站營運、分析和個人化服務之目的。
若您繼續瀏覽本網站,即表示您同意本網站使用Cookies。