Eighteen new limonoids, including eight methyl angolensates (1–8) and 10 cipadesins (9–18), were isolated from the leaves of Cipadessa baccifera. Their structures were characterized by means of spectroscopic data analyses, single-crystal X-ray diffraction, and quantum chemistry computational methods. The C-6 configurations in those compounds possessing a C-6 hydroxy group were all assigned as S regardless of the magnitude of J_5,6, and the C-2′ configuration in those bearing a 2-methylbutyryl residue was defined by single-crystal X-ray diffraction and NMR data. Compounds 1, 5, 6, 7, 11, and 12 showed moderate antimalarial activities with IC₅₀ values ranging from 12 to 28 μM.

中文翻译：

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来自 Cipadessa baccifera 的柠檬苦素。

十八新柠檬苦素，其中包括8个甲基angolensates（18）和10个cipadesins（9 - 18）中，从叶分离Cipadessa baccifera。通过光谱数据分析、单晶 X 射线衍射和量子化学计算方法对其结构进行了表征。无论J _5,6的大小如何，具有 C-6 羟基的化合物中的 C-6 构型均指定为S，而带有 2-甲基丁酰基残基的化合物中的 C-2' 构型定义为单-晶体 X 射线衍射和核磁共振数据。化合物1，5，6，7，11，和12显示出中等带IC抗疟疾活性_50个值范围从12到28微米。