| 摘要: | 台灣懸鉤子 (Rubus formosensis Ktze，RF)，屬薔薇科植物。在台灣民間常用於治療發炎相關的症狀，如發癢、痔瘡與牙痛。本研究之主要目的為利用DPPH自由基清除能力試驗、Trolox當量抗氧化能力試驗和總酚含量測定試驗等三個篩選平台，以活性目標分離方式進行分離台灣懸鉤子地上部之抗氧化活性成分。由台灣採集台灣懸鉤子地上部，以水及95 %乙醇進行萃取，得到水及95 %乙醇二種萃取物，分別標示為RFW及RFE。將此兩種萃取物分別經由DPPH自由基清除能力試驗、Trolox當量抗氧化能力試驗和總酚含量測定試驗，結果顯示，RFW的抗氧化能力比RFE佳。因此，再以水進行RF之大量 (1.10 Kg) 萃取，得到RFW萃取物 (352.12 g)，將255.73 g RFW依序以二氯甲烷、乙酸乙酯及正丁醇等三種溶媒做分配萃取，分別得到二氯甲烷層萃取物 (RFWC)、乙酸乙酯層萃取物 (RFWA)、乙酸乙酯的乳化層萃取物 （RFWAE）、正丁醇層萃取物 (RFWB)、正丁醇的乳化層萃取物 （RFWBE）及水層萃取物 (RFWW) 六層萃取物。將這六層分配萃取物進行抗氧化能力試驗，結果顯示，RFWB萃取層具有最佳抗氧化能力。RFWB萃取層再經由Diaion管柱層析分離，可獲得RFWB1~7七個分層，將這七個分層進行抗氧化能力試驗，結果顯示，RFWB3具有最佳抗氧化能力。
此外，在RFWB共分離得到 (1) 及 (2) 結晶化合物，經由各種光譜分析及文獻比對鑑定為Ellagic acid及Gallic acid。Ellagic acid及Gallic acid提供台灣懸鉤子抗氧化活性成分之來源。
Rubus formosensis Ktze (RF, Rosaceae) has been used as a folk medicine in Taiwan to treat inflammation related symptoms such as anti-pruritics, piles, and toothache. The aim of this study was to isolate the antioxidative constituents from RF according to the activity-guided isolation process. DPPH radical scavenging ability, Trolox equivalent antioxidant capacity and total phenol contents were applied as screening platforms. The aerial part of RF was collected in Taiwan. The RF was extracted with H2O and 95 % EtOH to obtain RFW and RFE extracts, respectively. The two extracts were determined by DPPH radical scavenging ability, Trolox equivalent antioxidant capacity, total phenol contents, and the results showed that the most potent antioxidative extract was RFW. A large amount (1.10 Kg) of RF was extracted with H2O and obtained 352.12 g of RFW extract. The 255.73 g of RFW was partitioned with CH2Cl2, EtOAc, and n-BuOH solvents to obtain six extracts, including CH2Cl2 layer extract (RFWC), EtOAc layer extract (RFWA), EtOAc emulsion layer extract (RFWAE), n-BuOH layer extract (RFWB), n-BuOH emulsion layer extract (RFWBE), and H2O layer extract (RFWW), respectively. The six extracts were evaluated by antioxidative activities assays, and the results showed that the most potent antioxidative extract was RFWB. RFWB extract was subjected a Diaion column chromatography to obtain seven fractions, RFWB1~7. RFWB1~7 were evaluated by antioxidative activities assays, and the results revealed that the most potent antioxidative fraction was RFWB3.
Compounds of (1) and (2) were isolated from RFWB, their structures were elucidated Ellagic acid and Gallic acid by spectroscopic analysis and comparing with authentic standards of Ellagic acid and Gallic acid. Ellagic acid and Gallic acid offered antioxidative activity source of Rubus formosensis. |
