Ten new cassane diterpenoids, caesalpulcherrins A–J (1–10), together with 11 known analogues (11–21) were isolated from the aerial parts of Caesalpinia pulcherrima. Their structures and relative stereochemistry were elucidated by spectrometric and spectroscopic methods, including one-dimensional (1D) and two-dimensional (2D) NMR, high-resolution electrospray ionization mass spectrometry (HRESIMS), and single-crystal X-ray diffraction analysis. Compounds 1–4 represent the first examples of 2,5-dimethoxyfuranocassane diterpenoids. Results of the antifeedant activity indicated that isovouacapenol C (12) and pulcherrin N (14) exhibited remarkable antifeedant activity against Mythimna separate with EC₅₀ values of 3.43 and 4.20 μg/cm², respectively. Meanwhile, pulcherrimin C (13) and 12-demethyl neocaesalpin F (18) exerted significant antifeedant activity against Plutella xylostella with an EC₅₀ data of 4.00 and 3.05 μg/cm², respectively. Some of the compounds showed obvious toxic activity against the plant-feeding generalist insect herbivores, M. separate and P. xylostella, at 0.8 mg/mL (800 ppm). Furthermore, the structure–activity relationships of antifeedant and insecticidal activities are also discussed in the article.

中文翻译：

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从地上部分Cassane二萜红蝴蝶及其拒食和对杀虫活性粘虫和小菜蛾

十新cassane二萜类化合物，caesalpulcherrins甲-J（1 - 10），加上11个已知类似物（11 - 21）从地上部分分离红蝴蝶。通过光谱和光谱方法，包括一维（1D）和二维（2D）NMR，高分辨率电喷雾电离质谱（HRESIMS）和单晶X射线衍射分析，阐明了它们的结构和相对立体化学。化合物1 - 4表示2,5-二萜dimethoxyfuranocassane第一实施例。拒食活性的结果表明异戊烯酚C（12）和pulcherrin N（12）。14）显示出对Mythimna的显着的拒食活性，EC ₅₀值分别为3.43和4.20μg/ cm ²。同时，pulcherrimin C（13）和12-demethyl neocaesalpin F（18）对小菜蛾具有显着的拒食活性，EC ₅₀数据分别为4.00和3.05μg/ cm ²。一些化合物对以植物为食的普通昆虫食草动物，分离支原体和小菜蛾具有明显的毒性。浓度为0.8 mg / mL（800 ppm）。此外，文章还讨论了拒食和杀虫活性的构效关系。