| Summary: | 碩士 === 高雄醫學大學 === 天然藥物研究所 === 88 === In a series of studies on the constituents of Formosan rutaceous plants, twenty-nine compounds have been isolated from the root bark of Melicope semecarpifolia (Merr.) Hartley and their structures were elucidated by spectral analysis. Among them, fourteen are alkaloids: evolitrine (1), pteleine (2), (R)-(+)-platydesmine (3), (R)-(-)-7,8-dimethoxyplatydesmine (4), cis-(+)-7,8-dimethoxymyrtopsine (5), (R)-(-)-8,9-dimethoxygeibalansine (6), semecarpifoline (7), 2-acetylevolitrine (8), 2-acetylpteleine (9), confusameline (10), dictamnine (18), kokusaginine (19), skimmianine (20) and haplopine (21); six are coumarins: osthenol (12), osthole (13), 7-O-prenylumbelliferone (14), xanthyletin (26), anisocoumarin H (28) and umbelliferone (29); one is flavonoid: ayanin (11) and other compounds are -sitosterol (15), stigmasterol (16), campesterol (17), methyl vanillate (22), syringic acid (23), tetracosyl ferulate (24), methyl oleate (25) and 5-hydroxymethylfurfural (27).
1, 2, 4, 5, 6, 7, 8, 9, 13, 14, 18, 22, 23, 24, 25, 26, 27 and 28 were known compounds and isolated for the first time from this plant. Semecarpifoline (7), 2-acetylevolitrine (8) and 2-acetylpteleine (9) are new compounds in nature. In addition, (S)-(-)-7,8-dimethoxyplatydesmine (4), cis-(+)-7,8-dimethoxymyrtopsine (5) and (R)-(-)-8,9-dimethoxygeibalansine (6) were determined the []D or their configuration in this study.
Bioassay-guided fractionation has resulted in the isolation of ten compounds with antiplatelet aggregation activities in vitro. Compounds 1 and 13 showed completely inhibitory activity at 100μg/ml on platelet aggregation induced by arachidonic acid, collagen and PAF in vitro. Compuond 20 showed completely inhibitory activity at 100μg/ml on platelet aggregation induced by arachidonic acid and collagen in vitro. Compuond 10, 18, 19 and 21 showed completely inhibitory activity at 100μg/ml on platelet aggregation induced by arachidonic acid in vitro. Compuond 3, 12 and 28 showed completely inhibitory activity at 100 μg/ml on platelet aggregation induced by collagen in vitro.
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