- 學位論文
瓊麻葉部活性成分及葉部人工受損反應之研究
The Active Constituents and Wound Response of the Leaves of Agave sisalana
摘要
從瓊麻葉部甲醇萃取物中分離出兩個新的固醇類皂素，S8與S10，三個黃酮類 (F1, F2, F3)，七個homoisoflavone類化合物 (H1-H7)，七個固醇類苷元與皂素 (S1-S7)，一個furostanol皂素 (S9) 與十三個已知的化合物。 兩個新化合物S8與S10的結構鑑定是利用一維與二維的核磁共振實驗與質譜儀決定。除此之外，經酸水解後利用氣相層析儀搭配火焰離子檢測器決定化合物S8與 S10中醣的組成。其他的已知化合物則以光譜分析與文獻比對決定其結構。 由瓊麻分離出來的黃酮類與homoisoflavonoids進行免疫調節的活性試驗。實驗以人類周邊單核細胞 (PBMC) 當作標的細胞，並且偵測細胞攝入3H-thymidine的量來測定細胞增生的數量。其中，化合物(±)-3,9-Dihydroeucomin (H3), dihydrobonducellin (H4), 與 5,7-dihydroxy-3-(4’-hydroxybenzyl)-4-chromanone (H6)可有效抑制由植物凝集素 (Phytohemagglutinin; PHA) 引起之增生現象，其半抑制濃度分別為19.4、73.8及 58.8 μM。此三個化合物同時能顯著的抑制PBMC產生IL-2與IFN-γ蛋白質表現且呈濃度相關性反應。 固醇類苷元與皂素化合物S1− S10進行細胞毒性試驗，篩選了乳癌 (MCF-7)、肺癌 (NCI-H460)、中樞神經癌 (SF-268) 等三種細胞株。其中以化合物S10表現出最高的細胞毒性，其半抑制濃度對此三株細胞株分別為1.2、3.8及 1.5 µM。 將瓊麻葉片經人工損傷，採集不同的時間點，用高效能液相層析儀與質譜儀進行分析，發現化合物S9成分在處理前後有顯著改變。推測此物質為瓊麻在遭遇葉片損傷時為有作用的物質，而其真正在瓊麻受損時化合物S9真正的作用將有待進一步的研究。
並列摘要
Two new steroidal saponins, S8 and S10, three known flavones F1, F2, F3, seven known homoisoflavonoids H1-8, seven known steroidal sapogenins and saponins S1-S7, one furostanol saponin S9, and thirteen known compounds were isolated from the methanolic extract of the leaves of Agave sisalana Perrine ex Engelm. The structures of the new compounds were identified and characterized by 1D and 2D NMR spectroscopy and mass spectrometry. In addition, acid hydrolysis and GC-FID were used to confirm the sugar moieties of S8 and S10. Other known structures were elucidated on the basis of spectroscopic analysis. The isolated flavones and homoisoflavonoids from A. sisalana were also evaluated for immunopharmacological activity. PBMC were used as target cells, and cell proliferation was determined by 3H-thymidine uptake. (±)-3,9-Dihydroeucomin (H3), dihydrobonducellin (H4), and 5,7-dihydroxy-3-(4’-hydroxybenzyl)-4-chromanone (H6) showed inhibitory effects on PBMC proliferation activated by PHA with IC50 values 19.4, 73.8, and 58.8 μM, respectively. All three compounds significantly inhibited the production of IL-2 and IFN-γ in activated PBMC in a concentration-dependent manner. The cytotoxic effects of compound S1− S10 on MCF-7, NCI-H460, and SF-268 cancer cells were evaluated, compound S10 was found to be the most potent with IC50 values of 1.2, 3.8, and 1.5 µM, respectively, against these three cell lines. The wounded leaves of A. sisalana were collected at different intervals and their extracts analyzed by HPLC and LC-ESI-MS. The amound of compound S9 was significantly different between healthy and wound spectrum. Compound S9 was suggested to be a marker compound although its detail mechanism and the physiology in the plant remain to be unknown.