| 摘要: | Natural products are one of the most essential sources of the chemical structures for developing medicines. Knowledge of traditional medicine was employed to investigate the potential plants used for treating human diseases. Although many herbs had already been studied and published in traditional herbs dictionary, many unstudied plants have efficient treatment of many diseases. Therefore, this dissertation aims to discover the bioactivities and components of those medicinal plants according to modern experiments. After referring to local traditional doctors and books, two plants from Vietnam, Stahlianthus thorelii, and Polycarpaea arenaria, together with one Taiwanese plant, Entada pursaetha, were chosen further investigate components and bioactivities base on their traditional usages.
In the research of S. thorelii, one new C-benzylated dihydrochalcone derivative, ST-C1 (1), two new polyphenol ST-C10 (10), ST-C11 (11), and six known compounds were isolated following by bioassay-guided fractionation and isolation scheme. Besides, compounds 1 and 3 displayed the most potent cytotoxicity on human cell lines (WiDr, A549, and HepG2), notably, IC50 values on HepG2 <10 µM. Besides, those compounds also expressed anti-NO activity, which showed IC50 values <10 µM. Furthermore, compounds 3 and 4 two significant compounds, were quantified and validated by the HPLC-UV method. The investigation of P. arenaria obtained seven new oleanane-type triterpene saponins, compounds 13-19, together with four known compounds. Among those isolates, compounds 15, 16, 18, and 19 exhibited IC50 values of 6.0-9.9 µM against different cell lines (A549, HTC116, PC3, and RT112). While in the antiangiogenesis assay, compounds 15, 16, 17, and 19 displayed IC50 values of < 5 µM. Hence, PA-C4 (16) showed the most promising effects in inhibiting cancer cell proliferation and angiogenic activities. We have isolated six new triterpene saponins (24, 26-30) and four known compounds from Entada pursaetha.
All compounds were elucidated based on spectroscopic and spectrometric analysis, especially 2D NMR, HRMS, IR, optical rotation, and comparisons with published data. Also, the structures of compounds 1 and 2 were further confirmed by X-ray crystallographic. |
