Five new acridone alkaloids, citracridone-I (1a), -II (1b), citpressine-I (2a), -II (2b), and prenylcitpressine (3) along with a known acridone alkaloid, 5-hydroxynoracronycine (5), and three known coumarins, clausarin (6), suberosin (7a), and xanthyletin (8) were isolated from the root bark of Citrus depressa (Rutaceae) collected in Taiwan and characterized. This is the first report of isolation of acridone alkaloids from Citrus species. In the structure elucidations, the use of nuclear Overhauser effect (NOE) experiment on the O-methoxymethyl derivatives of phenolic acridone alkaloids was shown to be useful for the determination of the location of the phenolic hydroxyl groups.
从台湾采集的Citrus depressa(芸香科)根皮中分离出五种新的
吖啶酮生物碱,即citracridone-I (1a)、-II (1b)、citpressine-I (2a)、-II (2b)和prenylcitpressine (3),以及一种已知的
吖啶酮生物碱5-hydroxynoracronycine (5)和三种已知的
香豆素,即clausarin (6)、suberosin (7a)和xanthyletin (8),并对其进行了表征。这是首次从柑橘属植物中分离出
吖啶酮生物碱的报告。在结构阐明中,
对酚吖啶酮生物碱的O-甲氧基甲基衍
生物进行核Overhauser效应(NOE)实验,可有效确定
酚羟基的位置。