Abstract From the leaves of Isatis indigotica Fortune, one new alkaloid, namely (2E)-N-(2-hydroxyphenyl)-2-(1-hydroxy-3-oxoindolin-2-ylidene) acetamide (1), together with four known ones, such as phaitanthrin D (2), methyl quindoline-11-carboxylate (3), cephalandole B (4) and 2,2-di (3-indolyl)-3-indolone (5) were isolated and identified. The structure of compound 1 was elucidated by means of spectroscopic analysis, including HRESIMS together with 1D and 2D NMR experiments. Compounds 1, 2 and 5 were obtained from this genus for the first time. Chemotaxonomic significance of these compounds is described herein.

中文翻译：

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板蓝根叶生物碱及其化学分类学意义

摘要 从菘蓝的叶子中提取出一种新的生物碱，即 (2E)-N-(2-hydroxyphenyl)-2-(1-hydroxy-3-oxoindolin-2-ylidene) 乙酰胺 (1)，以及四种已知的分离并鉴定出苯菊酯 D (2)、喹啉-11-羧酸甲酯 (3)、头孢菌素 B (4) 和 2,2-二 (3-吲哚基)-3-吲哚酮 (5) 等。化合物1的结构通过光谱分析阐明，包括HRESIMS以及1D和2D NMR实验。化合物 1、2 和 5 为首次从该属中获得。本文描述了这些化合物的化学分类学意义。