第一部分：小果葉下珠和金新木薑子葉部成分之分離及利用高效液相層析－固相萃取－核磁共振之分析研究 第二部分：皇后葵抑制甲型葡萄糖水解酶活性成分之研究 第三部分：寬筋藤根莖部分之化學成分研究

Part 1 Chemical investigation of Phyllanthus reticulatus and Neolitsea sericea var. aurata by HPLC-SPE-NMR and general methods Part 2 α-Glucosidase inhibitors from Syagrus romanzoffiana Part 3 Chemical constituents from the stems of Tinospora sinensis

林少紅(Sio-Hong Lam)

指導教授 ： 李水盛

國立臺灣大學/醫學院/藥學研究所/博士(2008年)

https://doi.org/10.6342/NTU.2008.02514

摘要

第一部分 小果葉下珠和金新木薑子葉部成分之分離及利用高效液相層析－固相萃取－核磁共振之分析研究
小果葉下珠為大戟科植物，印度民間傳統用藥，多用於治療骨折和外傷。有報告指出此植物具有細胞毒性和抗微生物活性，本實驗目的為研究其化學成分以利於闡述這些活性。小果葉下珠之葉部甲醇萃取物以極性分割得到氯仿可溶部分、正丁醇可溶部分和水可溶部分。正丁醇可溶部分經由層析管柱分離，共得到二個固醇類化合物(1-2)、四個多酚類(3-6)和二個黃酮類(7-8)。同時，小量的正丁醇可溶部分經過分子凝膠管柱前處理後，以HPLC-SPE-NMR進行分析，再得到一個多酚類(9)和三個黃酮類(10-12)化合物。而在金新木薑子的葉部成分研究，亦出現相似的結果。本研究再次証明HPLC-SPE-NMR連接技術祇須利用小量的物材料，即可對特定天然物作徹底之分析研究。

第二部分 皇后葵抑制甲型葡萄糖水解酶活性成分之研究
甲型葡萄糖水解酶抑制劑是一種口服降血糖用藥，能有效降低碳水化合物在腸道的吸收。以抑制甲型葡萄糖水解酶活性為導引，自皇后葵種子之酒精萃取物中共分離得到十四個化合物(18-31)。這些化合物中，有五個是新化合物(22-23, 25-27)，而且皆具有抑制甲型葡萄糖水解酶的活性；在體內動物實驗中，正常老鼠利用口服蔗糖實驗，證實化合物3, 3', 4, 5, 5'-pentahydroxy-trans-stilbene (18)和化合物kompasinol A (21)能有意義地降低飯後血糖值。為更完整研究皇后葵的成分，將經由Sephadex LH-20前處理且富含此類化合物的部分，利用HPLC-SPE-NMR進行分析，鑑定得到三個stilbenoids類化合物(32-34)。本研究顯示由皇后葵得到的stilbenoids類化合物，可為降血糖藥物的前導藥物。

第三部分 寬筋藤莖部分之化學成分研究
寬筋藤之莖部為傳統民間草藥，一般用以清熱、止痛，有研究指出本植物具有抗發炎和免疫調節作用。因此，本實驗希望分離其化學成分作為日後研究其化學及藥理活性之用。本植物莖部酒精萃取物經極性分割後，正丁醇可溶部分經由離心分配層析、分子凝膠管柱層析和逆相低壓管柱層析分離，共得到十一個砆喃型clerodane雙萜類成分(35-45)，其中化合物2-lactoyl-6β-borapetoside B (39)和化合物45是新天然化合物。本實驗以簡單有效的步驟，由寬筋藤中得到克級的雙萜類化合物，可作為日後研究雙萜類化學修飾和構效關係研究之豐富資源。

關鍵字

小果葉下珠 ； 金新木薑子 ； 皇后葵 ； 寬筋藤 ； 高效液相層析－固相萃取－核磁共振

並列摘要

Part 1. Chemical investigation of Phyllanthus reticulatus and Neolitsea sericea var. aurata by HPLC-SPE-NMR and general methods
Phyllanthus reticulatus Poir., a traditional Indian herb (Euphorbiaceae), is used as medicine for the fractures and traumatic injury. Some reports have shown its cytotoxic and antimicrobial activity. This work was aimed to study its chemical constituents to rationale these bioactivities.The MeOH extract of its leaves was divided into fractions soluble in CHCl3, n-BuOH and H2O. Most of the n-BuOH layer was chromatographed over silica gel and Sephadex LH-20 columns, to yieled two sterols (1-2), four well-known polyphenolics (3-6) and two flavonoids (7-8). In the meantime, small amount of the n-BuOH layer after Sephadex LH-20 fractionation was subjected to LC-SPE-NMR analysis, leading to the identification of one polyphenolic (9) and three additional flavonoids (10-12). A similar result was also found in the research on the Neolitsea sericea var. aurata. In this study, we demonstrate that HPLC-SPE-NMR technique, using small amounts of plant materials (1~2 g dry leaves), is efficient and powerful in phytochemical analysis of selected natural porducts.

Part 2. α-Glucosidase inhibitors from Syagrus romanzoffiana
α-Glucosidase inhibitors, a class of orally administered hypoglycemic agents for type 2 diabetes, can decrease the absorption of carbohydrates from the intestine. Bioassay-guided fractionation against α-glucosidase has resulted in isolation and characterization of fourteen active compounds (18-31) from the EtOH extract of the seeds of Syagrus romanzoffiana. Of these, ten are stilbenoids, and five of them (22-23, 25-27) are new compounds and possess potent inhibitory activity against α-glucosidase. The in vivo assay on normal Wistar rats using oral sucrose challenge also demonstrated that kompasinol A (21) and 3, 3', 4, 5, 5'-pentahydroxy-trans-stilbene (18) possess significant effect in reducing the postprandial blood glucose level. A stilbenoid rich fraction, obtained from Sephadex LH-20 fractionation, was also studied using LC-SPE-NMR technique, leading to the characterization of three additional stilbenoids (32-34). These results suggest that stilbenoids from S. romanzoffiana might be used as a lead for development of hypoglycemic agents.

Part 3. Chemical constituents from the stem of Tinospora sinensis
The stems of Tinospora sinensis has been used as folklore medicine for antipyretic and analgesia. Some studies have shown its anti-inflammatory activity and immunomodulatory activity. Hence, this study was aimed to isolate its chemical constituents for further chemical and pharmacological studies. The n-BuOH soluble fraction of the EtOH extract of the stems was chromatographed repeatedly over centrifugal partition chromatography, Sephadex LH-20 and reversed phase Lobar column to give eleven diterpenoids (35-45) of furan type clerodane. Moreover, 2-lactoyl-6β-borapetoside B (39) and compound 45 are new natural products. In this study, we developed a facile method to isolate gram-scale diterpenoids, which will be beneficial to chemical modification and structure-activity-relationship study.

並列關鍵字

Phyllanthus reticulatus ； Neolitsea sericea var. aurata ； Syagrus romanzoffiana ； Tinospora sinensis ； HPLC-SPE-NMR

參考文獻

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