以高效能液相層析-固相萃取-核磁共振儀 分析昆欄樹葉部之化學成分

Abstract

液相層析-固相萃取-核磁共振儀串聯技術是近年才發展出來的高效率分析技術。本研究以液相層析-固相萃取-核磁共振儀分離鑑定昆欄樹葉部甲醇萃取物之化學成分。昆欄樹為分佈在東亞地區之地區性植物。取昆欄樹葉部甲醇萃取物以水、氯仿、正丁醇進行極性分割，正丁醇濃縮物再以水和乙酸乙酯層做極性分配，經由離心式分配層析儀及矽膠管柱和Sephadex LH-20進行劃割之後，運用液相層析-固相萃取-核磁共振儀連結技術的高效率解析進行研究 , 搭配質譜儀所測出的分子量數據解析出天然物成分之結構。結果顯示此部分為富含木質素類化合物，所分析出的化合物多為首次在該植物發現，其中有massonianoside D(1)、7、8和C-veratroylglycol (9)為已知化合物，而2~6、10~14是新穎天然物成分。

由液相層析-固相萃取-核磁共振儀所分析鑑定出的化合物中，其中多為新木脂體類(neolignans)骨架，此類結構過去文獻曾報導小鼠血癌細胞P-388有活性；也有實驗證實能促進菸草細胞分裂快速；對抗氧化能力也有文獻提出。故藉由在LC-SPE-NMR裡所找到的最佳分離條件套用於半製備型管柱層析，以此分離出足夠的量來解析並補足新穎化合物所需之實驗數據以及進行活性測試。因此，藉由液相層析-固相萃取-核磁共振儀/質譜儀來分析天然物成分，能大幅提升研究之效率和節省天然材料及溶劑的使用量。

In order to investigate the chemical constituents as well as their relevant bioactivities, the methanolic extract from the leaves of Trochodendron aralioideo was analyzed by the efficient technique of LC-SPE-NMR in combination with other analytical methods. The methanolic extract was partitioned among solvents of different polarity, and then followed by successive separation and fractionation with centrifugal partition chromatography, silica gel and Sephadex LH-20 column chromatographies. Finally, the fraction of particular interest was analyzed by the LC-SPE-NMR technique to reveal each component in the fraction. From the NMR spectral data accompanying the analysis, sometimes supplemented by mass spectral information, the structure of each component was elucidated and ascertained. Summarizing the results from this analysis, it was revealed that the analytic contained abundant components of neolignans , having dimeric phenyl propanoid structure with unsymmetrically condensed benzofuran skeleton attached with different sugar moieties. So far such components have been isolated and characterized in this study, including massonianoside D(1), C-veratroylglycol(9), 2~8, 10~14, all being newly discovered constituents from this plant. Among them, 1, 7, 8 and 9are known compounds and 2~6, 10~14 are new structures among natural products. The best isolation conditions secured from the LC-SPE-NMR analysis will be adopted and modified in scale–up separation by semi-preparative column chromatography. Thus, sufficient amount for each interesting component will be obtained and provided for further investigation in spectral and structure information, as well as exploration in biological activities and relevant QSAR studies.