摘要
本研究以甲醇萃取大憨蓮的各部位，包括蓮藕、蓮葉、蓮花、蓮蓬及蓮子，並測定各部位萃取物之抗氧化能力，結果顯示以蓮蓬萃取物具有最高之DPPH、ABTS及超氧陰離子自由基清除能力，其中ABTS 自由基清除能力與抗壞血酸相似。蓮蓬萃取物亦具有最高之還原力及脂質過氧化抑制能力，但以蓮藕萃取物具有最佳之亞鐵金屬離子螯合能力。經皮爾森相關性分析後發現，大憨蓮自由基清除能力、還原力與脂質過氧化抑制能力與總酚及原花青素含量具有正相關。利用Sephadex LH-20管柱層析將具有最高抗氧化能力之蓮蓬甲醇萃取物進行分離，得到十一個區分，其中以S2 區分具有最佳之DPPH 自由基清除能力，EC50 為21.2 μg/ml，其次為Q2、R2、S1 及S3 區分。進一步將Q2、R2、S1、S2 及S3 區分進行硫解，經HPLC 分析，發現S2區分含有八個單體成份，經由ESI-MS (-)鑑定出S2 區分其原花青素聚合物組成之單體含有gallocatechin 及epigallocatechin 兩種。
並列摘要
The methanolic extracts of rhizomes, leaves, petals, seedpods and seeds from Nelumbo nucifera were examined for their antioxidant activities. The results showed that methanolic extract of the seedpods had the highest antioxidant activity against radical scavenging activity, ferric reducing antioxidant power, and inhibition of lipid peroxidation. It was noteworthy that methanolic extract of seedpods exhibited similar activity to ascorbic acid in ABTS radical scavenging activity. But the highest ferrous ion chelating activity was found in methanolic extract from the rhizomes of lotus. In addition a positive correlation between antioxidant activity and contents of total phenolics and proanthocyanidins were obtained. Methanolic extract of lotus seedpod was further separated by Sephadex LH-20 column chromatography into eleven fractions. The S2 fraction exhibited the highest DPPH radical scavenging activity with an EC50 value of 21.2 μg/ml, followed by Q2, R2, S1 and S3 fractions. The chemical constituents of S2 fraction was performed by acid-catalyzed degradation in the presence of tolunene-α-thiol. Eight components were characterized by reversed-phase HPLC. Gallocatechin and epigallocatechin were identified by electrospray ionization mass spectrometric negative detection.
參考文獻
延伸閱讀
- 邱思魁、陳翠卿（2009）。數種藥用植物甲醇及熱水萃取物的抗氧化性。臺灣農業化學與食品科學，47(5)，260-267。https://doi.org/10.6578/TJACFS.2009.029
- Liu, Y. C. (2008). 重陽木及火炭母草甲醇萃取物及其區分層之抗氧化性 [master's thesis, Tatung University]. Airiti Library. https://www.airitilibrary.com/Article/Detail?DocID=U0081-0607200917245204
- Hou, W. C., Wu, W. C., Yang, C. Y., Chen, H. J., Liu, S. Y., & Lin, Y. H. (2004). 麥門冬葉子的甲醇與熱水抽取物抗氧化活性之研究. Botanical Bulletin of Academia Sinica, 45(4), 285-290. https://doi.org/10.7016/BBAS.200410.0285
- 陳薪喨、林昀蓉、王蓉敏、周培萱、陳美慧、黃敏鳳、洪彰岑、林榮宗、林文傑（2011）。大花咸豐草超臨界流體萃取物抗氧化、抗發炎能力研究。加馬，(42)，9-17。https://doi.org/10.30173/JG.201106.0002
- 賴柏安（2021）。Evaluation of hepatoprotective potential of lotus leaf water extract by promoting Nrf2 and epigenetics-mediated cellular antioxidant capacity〔碩士論文，中原大學〕。華藝線上圖書館。https://doi.org/10.6840/cycu202100949