臺灣博碩士論文加值系統

西瓜 [Citrullus lanatus (Thunb.) Matsum. & Nakai]，為一種藤本開花植物，原產自非洲北部。是一具有平滑堅硬表皮及多汁的水果。目前，全世界已有數百栽培種的西瓜，其中包含有籽品種以及無籽品種被廣泛種植並用於商業用途。本篇研究中，乾燥之西瓜莖部以甲醇浸泡，其甲醇萃取物經由分配萃取法得到乙酸乙酯層萃取物、正丁醇層萃取物以及水層萃取物。在初期的細胞毒殺、抗氧化能力以及保肝實驗中，乙酸乙酯層萃取物顯示具有細胞毒殺效果。乙酸乙酯層萃取物再經由管柱層析分離出十八組分液，其中有八組分液有明顯之細胞毒殺能力。進一步在乙酸乙酯層萃取物中有活性功效之分液以管柱層析、高效液相層析與再結晶等方法進行分離以及純化，經由紫外線光譜、紅外線光譜、質譜以及核磁共振光譜分析並進行文獻查閱，目前共鑑定出四十一個化合物，包括三個雙萜類、八個三萜類、六個固醇類、十五個芳香族類、二個生育醇類、三個木酚素類、三個生物鹼類及一個倍半萜類。

Citrullus lanatus (Thunb.) Matsum. & Nakai, a vine-like and flowering plant that originated in northern Africa. It is a fruit has smooth external rind and juicy interior flesh. Nowadays, watermelon has a few hundred of cultivars, both seeded and seedless are cultivated and used commercially in this world. In this study, air-dried stems of C. lanatus were extracted with methanol (MeOH). The MeOH extract was suspended in H2O, and then partitioned sequentially using EtOAc and n-BuOH. In the preliminary cytotoxic, antioxidant and hepatoprotective assays, the EtOAc layer of the stems of C. lanatus exhibited cytotoxic activity. The EtOAc layer was separated into eighteen fractions by silica gel chromatography. Among them, eight fractions showed significant cytotoxic activities. Furthermore, the bioactive fractions were purified by repeated column chromatography, high performance liquid chromatography (HPLC) and recrystallization to yield forty-one chemical compounds including three diterpenoids, eight triterpenoids, six steroids, fifteen aromatics, two tocopherols, three lignans, three alkaloids and one sesquiterpene. Their structures were elucidated by spectroscopic analysis including UV, IR, EI-MS, 1H- and 13C-NMR techniques.

目錄
圖目錄 IV
表目錄 VII
壹、前言 1
一、 緒言 1
二、 植物簡介 2
三、 文獻回顧 6
(一) 已發現之西瓜之化學成分 6
(二) 西瓜屬植物之藥理活性 11
四、實驗動機 12
貳、材料與方法 13
一、西瓜莖部化學成分之分離與純化 13
(一) 實驗藥品與儀器 13
(二) 實驗方法 14
二、細胞毒殺活性試驗 19
(一) 實驗原理 19
(二) 實驗藥品與儀器 20
(三) 實驗方法 21
三、DPPH自由基清除效應試驗 23
(一) 實驗原理 23
(二) 實驗藥品與儀器 24
(三) 實驗方法 24
四、抵抗T-BHP誘導肝細胞氧化損傷之細胞保護作用 25
(一) 實驗原理 25
(二) 實驗藥品與儀器 26
(三) 實驗方法 27
參、結果與討論 28
一、西瓜莖部化學成分之分離纯化 28
二、化合物結構摘要 32
三、主要化合物結構解析 38
(一) Ursane type骨架之三萜類化合物 38
(二) Oleanane type骨架之三萜類化合物 38
(三) Cycloartane type骨架之三萜類化合物 49
(四) 芳香族類化合物 58
(五) 固醇類化合物 73
四、細胞毒殺活性試驗 78

(一) 西瓜莖部甲醇萃取物與其各分層萃取物對人類肝癌細胞株 SK-Hep1毒殺活性結果 78
(二) 西瓜莖部乙酸乙酯層萃取物各區段對人類肝癌細胞株 SK-Hep1 之毒殺活性結果 79
五、DPPH自由基清除效應 80
(一) 西瓜莖部甲醇萃取物與其各分層萃取物之DPPH自由基清除效應 80
(二) 西瓜莖部乙酸乙酯層萃取物各區段之DPPH自由基清除效應 81
六、抵抗t-BHP誘導之肝細胞氧化損傷之細胞保護作用 82
(一) 西瓜莖部甲醇萃取物與其各分層萃取物抵t-BHP誘導之肝細胞氧化損傷之細胞保護作用 82
(二) 西瓜莖部乙酸乙酯層萃取物各區段抵抗t-BHP誘導之肝細胞氧化損傷之細胞保護作用 83
肆、結論 84
伍、化合物數據 86
參考文獻 100
作者簡介 113

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