Fourteen previously undescribed alkaloids comprising two N-1-hydroxymethylmacroline alkaloids, one talpinine-type oxindole acetal, a pair of equilibrating talpinine-type oxindole hemiacetals, eight oxidized derivatives of sarpagine- and akuammiline-type indole alkaloids, in addition to alstochalotine a diastereomer of gelsochalotine recently isolated from Gelsemium elegans, were isolated from the leaf and stem-bark extracts of Alstonia penangiana. The structures and relative configurations of these alkaloids were established using NMR, MS, and in one instance, confirmed by X-ray diffraction analysis. An NMR-based method is described as a useful chemotaxonomic tool for differentiating between A. penangiana and A. macrophylla. Several of the alkaloids isolated showed appreciable growth inhibitory effects when tested against a number of human cancer cell lines.

中文翻译：

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来自 Alstonia penangiana 的 Macroline、talpinine 和 sarpagine 生物碱。基于 NMR 的区分 A. penangiana 和 A. macrophylla 的方法

十四种以前未描述的生物碱，包括两种 N-1-羟甲基大环素生物碱、一种 talpinine 型 oxindole 缩醛、一对平衡的 talpinine 型 oxindole 半缩醛、8 种 sarpagine 和 akuammiline 型吲哚类生物碱的氧化衍生物，以及 chatosterine最近从 Gelsemium elegans 中分离出的gelsochalotine 是从Alstonia penangiana 的叶和茎树皮提取物中分离出来的。这些生物碱的结构和相对构型是使用 NMR、MS 建立的，并且在一种情况下，通过 X 射线衍射分析证实。基于 NMR 的方法被描述为一种有用的化学分类工具，用于区分 A. penangiana 和 A. macrophylla。