- 學位論文
闊葉骨碎補、箭葉鳳尾蕨和雙花耳草之活性成分
The Bioactive Constituents of Davallia solida, Pteris ensiformis and Hedyotis biflora
摘要
從闊葉骨碎補中，藉由捕捉自由基之活性導引分離法，得到四個為新化合物，十個已知化合物，其中mangiferin及其衍生物具有最佳的抗氧化活性。闊葉骨碎補塊莖水抽出物，以不同溶液進行液液萃取，得到不同劃分，並分別含有不同比例之總多酚化合物含量；正丁醇劃分之總多酚化合物含量均大於各劃分，可能與正丁醇劃分之抗氧化力較佳有關，加上在正丁醇劃分中得到的十四個化合物皆為酚類化合物，其中有十一個化合物比維他命E有更強的自由基捕捉活性，亦與結果相呼應。 從箭葉鳳尾蕨水抽出物中分離得到三個新化合物及五個已知化合物。針對箭葉鳳尾蕨水萃取物進行組分之高效能液相層析 (HPLC) 分析，發現箭葉鳳尾蕨水萃取物中caffeic acid 和hispidin 衍生物有較高含量與抗氧化活性，對於箭葉鳳尾蕨水抽出物抗氧化力，多酚類化合物佔重要角色，尤其是 caffeic acid、hispidin 及 kaempferol 等衍生物。 並將上述具抗氧化化合物依照其抗氧化活性，歸納其結構與活性的關係。 此外，從箭葉鳳尾蕨乙酸乙酯抽出物中分離得到四個新化合物，十三個已知化合物，其中兩個蕨酸衍生物，針對人類血癌細胞(HL 60)具有細胞毒殺活性。 另一方面，藉由細胞毒殺活性導引分離，將雙花耳草分離得到三個新化合物，十九個已知化合物，將雙花耳草植物中分離得到的化合物進行細胞毒殺實驗，測試不同細胞，其中三個新香豆素化合物、ursolic acid、oleanolic acid 和6'-(??-sitosteryl-3-O-??-D-glucopyranosidyl)-pentadecanoate 針對人類肝癌細胞（Hep G2）及乳癌細胞（MDA-MB-231、MCF-7）具有抑制作用。 最後，本研究首次證明闊葉骨碎補和箭葉鳳尾蕨的DPPH捕捉活性，是來自其富含的多酚類化合物，並從箭葉鳳尾蕨和雙花耳草中發現新的具癌細胞生長抑制作用的化合物，所有分離得到的化合物皆藉由一維、二維核磁共振光譜等物理數據和部分化方法確認其化學結構。
並列摘要
Using the DPPH radical scavenging activity-guided fractionation method, four new compounds were isolated from the aqueous extract of Davallia solida rhizome (DS), together with ten known compounds. Among them, mangiferin derivatives have the strongest antioxidant activity. Solvent partition yielded of aqueous extract different layers and total phenol content. n-Butanol layer has the highest phenol content. Among the fourteen compouds of n-butanol, eleven compounds have stronger free radicals scavenging activity than vitamin E. The antioxidant activity of DS may be therefore attributed in part to its constituents. Three new compounds were isolated from the aqueous extract of Pteris ensiformis Sword Brake fern (SBF) with five known compounds. HPLC with UV detector was further employed to analyze the content of each compound based on the retention time by comparison with isolated pure compounds. It was found that the most abundant phenolic compound in SBF were caffeic acid and hispidin derivatives. This data indicates that SBF is rich in phenolic antioxidants, especially derivatives of caffeic acid, hispidin and kaempferol. The antioxidants from DS and SBF, together with their antioxidant activity were discussed for the SAR (Structure Activity Relationship). Therefore, four new compounds, together with thirteen known compounds, were isolated from the ethyl acetate extract of Pteris ensiformis. Two pterosin derivatives.show cytotoxicity against HL 60 cells (human leukemia). In the other hand, using the bioactivity-guided fractionation method, three new coumarin derivatives were isolated from the methanol extract of Hedyotis biflora (HB), together with nineteen known compounds. Three new compounds, ursolic acid, oleanolic acid, and 6'-(??-sitosteryl-3-O-??-D-glucopyranosidyl)- pentadecanoate showed cytotoxicity against human tumor cell lines, Hep G2, MCF-7, and MDA-MB-231. In conclusion, we demonstrated for the first time that DS and SBF exhibited strong DPPH scavenging activity and fund out the new cytotoxic compounds from SBF and HB. The structural elucidation of all isolated compounds are base on spectroscopic analyses (mianly 1D and 2D NMR techniques), as well as chemical ecidence.