芋香林投地上部化學成分及生物活性之研究

芋香林投為露兜樹科 (Pandanaceae)露兜樹屬 (Pandanus)植物為一熱帶灌木，分布於東南亞而在台灣則為引進栽植種。在原產地菲律賓、泰國及馬來西亞常被用來作為食物矯味劑以及作為抗糖尿病、保肝及抑制腫瘤等功效民間用藥。本研究中發現芋香林投地上部之乙醇粗萃物在抗氧化，抗生物膜以及抗發炎等活性具有初步潛力，進而將此粗萃物以酸鹼萃取法分離出乙酸乙酯、二氯甲烷 (富含生物鹼)與水層。從生物鹼層分離出9個新化合物，包括norpandamarilactonine-C (5)與-D (6)、pandalizine-A (7)與-B (8)、pandamarilactam-3z (9)、pandamarilactone-2 (12)、-3 (13)與-33 (15)以及pandamarilactonine-I (16)，及13個已知化合物。此等化合物均藉由光譜分析來進行結構解析。這些生物鹼可分類成五種骨架，包括pandamarilactonines (1-4與16)、norpandamarilactonines (5與6)、indolizinones (7與8)、pandamarilactones (10-15) 與 pandamarilactams (9, 17與18)。且本研究利用HPLC成功分離出四個不同的6Z-pandamarilactonines立體異構物，並利用ECD預測數據配合實際CD光譜以決定其絕對立體。生物鹼層以及主要化合物 (1-4與11)具有抗氧化潛力活性。然而這些生物鹼在抗生物膜、抗發炎、抗血小板凝集以及細胞毒殺活性上均無顯著效果。惟以過去經驗而言，於自然界之生物鹼通常具有特殊生物活性。在本研究之露兜樹屬生物鹼具有獨特之gamma-alkylidene-alpha,beta-unsaturated-gamma-lactone, gamma-alkylidene-alpha,beta-unsaturated-gamma-lactam骨架等。但目前為止，尚未找到其特殊之生物活性，故仍有待進一步之研究。

關鍵字

芋香林投；酸鹼萃取法；生物鹼

並列摘要

Pandanus amaryllifolius Roxb. (Pandanaceae) is a tropical shrub that distributed in south-east Asia and introduced in southern Taiwan as a cultivated plant. In Philippines, Thailand and Indonesia, this plant is used as a flavoring and folk medicine for hyperglycemia treatment, liver protection and tumor growth inhibition. In the studies, the ethanolic extract of P. amaryllifolius aerial part showed potential antioxidant, anti-biofilm and anti-inflammatory activities. The extract was separated by an acid-base extraction method into EA, CH2Cl2 (alkaloid-rich) and H2O fractions. Nine new compounds, norpandamarilactonine-C (5) and -D (6), pandalizine-A (7) & -B (8), pandamarilactam-3z (9), pandamarilactone-2 (12), -3 (13) & -33 (15) and pandamarilactonine-I (16), together with thirteen known compounds, were isolated from the alkaloid-rich fraction. The structures of the isolates were elucidated by intensive spectroscopic analysis. Pandanus alkaloids were summarized in five skeletons, including pandamarilactonines (1-4 and 16), norpandamarilactonines (5 and 6), indolizinones (7 and 8), pandamarilactones (10-15) and pandamarilactams (9, 17 and 18). 6Z-Pandamarilactonines possessing four different configurations (1-4) were successfully separated by HPLC. The absolute configurations of 1-4 were identified by comparison of the ECD predicted data with the CD measured spectra. The alkaloid-rich fraction and the major compounds (1-4 and 11) showed potential antioxidant activity. However, they were inactive toward anti-biofilm, anti-inflammatory, anti-platelet aggregation and cytotoxicity activities. To the best of our knowledge, alkaloids always exhibit special bioactivities in nature. Whereas, pandanus alkaloids presented unique skeleton classes in this study, gamma-alkylidene-alpha,beta-unsaturated-gamma-lactone, gamma-alkylidene-alpha,beta-unsaturated-??-lactam etc. However, these compounds didn’t show special biological functions yet, and they should be further explored.