Hemitheion (1), a new sulfur-containing vobasane-type indole alkaloid, was isolated, together with three known compounds, vobasine (2), gelsedine (3), and gelsemicine (4), from the alkaloid extract of the stems of Mostuea brunonis Didr. (Gelsemiaceae). Compound 1 could be straightforwardly isolated. Its structure was elucidated by a combination of spectroscopic methods. Besides corresponding to a formerly postulated biosynthetic intermediate toward theionbrunonines, hemitheion (1) stands among the few monomeric vobasanes lacking an oxygen at C-3. Hemitheion (1) showed moderate antiplasmodial activity in the micromolar range against the strain FcB1 of Plasmodium falciparum and no cytotoxic activity against the MRC-5 cell line at 20 μM.

中文翻译：

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从 Mostueabrunonis 中靶向分离 Hemitheion，一种提议的 Theionbrunonine 生物合成中间体

Hemitheion ( 1 ) 是一种新的含硫vobasane 型吲哚生物碱，与三种已知化合物vobasine ( 2 )、gelsedine ( 3 ) 和gelsemicine ( 4 ) 一起从Mostuea茎的生物碱提取物中分离出来。brunonis Didr。（绞股蓝科）。化合物1可以直接分离。它的结构是通过光谱方法的组合阐明的。除了对应于先前假定的离子布鲁诺宁生物合成中间体之外，半硫离子 ( 1 ) 是少数在 C-3 处缺乏氧的单体 vobasanes 之一。Hemitheion ( 1) 在微摩尔范围内显示出对恶性疟原虫FcB1 菌株的中等抗疟原虫活性，并且在 20 μM 时对 MRC-5 细胞系没有细胞毒活性。