壹、越南巴豆之化學成分與其生理活性研究 貳、不同製程的烏龍老茶揮發性成分之探討

1.Study on the Chemical Constituents and Bioactivity of Croton tonkinensis Gagnep 2.Study on the Volatile Compounds in Various Old Oolong Tea Preparations with Different Procedures

賴苑羽(Yuan-Yu Lai)

指導教授 ： 郭賓崇

國立虎尾科技大學/文理學院/生物科技研究所/碩士(2011年)

摘要

由越南產植物越南巴豆（Croton tonkinensis Gagnep）的甲醇粗萃物共分離得到57個化合物，其中包含2個新的kaurane 及10個新的ent-kaurane二萜類化合物，15個已知的ent-kaurane二萜類化合物與30個其他類型的化合物。將部份分離得到的二萜類化合物，進一步測試癌細胞毒殺活性與抗發炎活性。結果發現化合物13與15對於癌細胞株具有很強的細胞毒殺活性，而化合物13, 14, 15, 28, 29及32則在小鼠腦神經膠細胞（murine microglial cell）具有抑制LPS誘導產生一氧化氮的活性，其IC50值均低於5 ?M，活性遠優於已知的抑制劑L-NAME。

本研究主要利用氣相層析質譜儀（GC-MS）比較新鮮烏龍茶以及烏龍老茶之揮發性成份的差異。研究發現，烏龍老茶具有數種獨特的揮發性成分是明顯有別於新鮮烏龍茶。新鮮烏龍茶中含有大量的長鏈醇類與酸類，經過長時間儲存及定期烘焙後會轉換成短鏈酸類並且產生許多含氮的胺基衍生物，例如?咯（pyrrole）與?啶（pyridine）。而烏龍老茶所具有的特殊芳香氣味主要由含氮雜環化合物所組成，例如N-乙基琥珀醯亞胺（N-ethylsuccinimide）、2-乙醯基?咯（2-acetylpyrrole）、2-甲醛基?咯（2-formylpyrrole）與3-羥基?啶醇（3-pyridinol）。另外將五種不同製作過程的烏龍老茶進行揮發性成分分析，結果發現此五種烏龍老茶所含揮發性成分是一致的，可作為日後鑑定烏龍老茶的指紋圖譜。此外，歷經長時間儲存但缺少定期烘焙的烏龍老茶或只歷經中度烘焙的烏龍老茶皆無法鑑定出此類獨特的揮發性成分。依據本研究結果顯示，要促使烏龍老茶獨特揮發性成分的形成，定期烘焙比長時間儲存更來的重要。

關鍵字

越南巴豆 ； 烏龍老茶

並列摘要

Phytochemical investigation of the methanolic extract of Croton tonkinensis Gagnep afforded two new kaurane and ten new ent-kaurane, fifteen known ent-kaurane type diterpenoids along with thirty known compounds. The isolates from this plant were selected to examine for their cytotoxic and anti-inflammatory bioactivities. Among these tested compounds, 13 and 15 showed the most significant cytotoxic activity against the tested A549, MCF-7, KB and KB-VIN tumor cell lines. In addition, compounds 13, 14, 15, 28, 29, and 32 were all potent than a non specific i-NOS inhibitor L-NAME in the inhibition of LPS-induced NO production in murine microglial cells with IC50 values less than 5 ?M.

In the present study, it was aimed to compare the volatile compounds in fresh and old oolong teas by aroma extract dilution analysis with the aid of gas chromatography/ mass spectrometry (GC-MS) analysis. Volatile compounds of old oolong tea were found significantly different from those of fresh oolong tea. The comparison suggested that long straight-chains alcohols and acids were possibly decomposed while shorter chain acids and their amide derivatives as well as many nitrogen-containing compounds, such as pyrrole and pyridine derivatives were generated during the conversion process. Aroma constituents in the old oolong tea were mainly composed of nitrogen-containing heterocycles, e.g., N-ethylsuccinimide, 2-acetylpyrrole, 2-formylpyrrole and 3-pyridinol. Overall patterns of volatile compounds in five different preparations of old oolong tea were found fundamentally identical, and thus might be regarded as a unique fingerprint for old oolong tea. The alteration of volatile compounds observed in the preparation of old oolong tea did not seem to be achieved by aging without drying or by mild drying. According to this study, drying process seems to be more important than aging process in terms of converting unique volatile compounds in old oolong tea.

並列關鍵字

Croton tonkinensis Gagnep ； old oolong tea

參考文獻

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