Bipolarsterols A−H (1−8), eight undescribed steroids were isolated from Bipolaris oryzae, along with nine known congeners. Their structures and absolute configurations were elucidated by comprehensive spectroscopic techniques, NMR and ECD calculations. Compound 1 presents the first example of a 19(l0→5)-abeo-7(8→9)-abeo-ergostane, featuring an unusual spiro[4.5]decan-6-one system, and compound 2 is a new member of the rare steroid-phenylpropanoid hybrid. Compound 5 showed remarkable cytotoxicity against HT29 cells with an IC₅₀ value of 5.8 μM. Compound 8 showed significant inhibitory effect on NO production in RAW264.7 with an IC₅₀ value of 2.7 μM, through the inhibition of iNOS levels at the transcription and protein levels as well as the NF-κB pathway.

中文翻译：

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双极甾醇 A，一种类固醇，具有前所未有的 6/5/6/5 碳骨架，来自植物病原真菌米极


从米双极甾醇 A-H （1-8） 中分离出 8 种未描述的类固醇，以及 9 种已知的同系物。它们的结构和绝对构型通过综合光谱技术、NMR 和 ECD 计算阐明。化合物 1 提出了 19（l0→5）-abeo-7（8→9）-abeo-ergostane 的第一个例子，具有不寻常的螺[4.5]癸-6-酮系统，化合物 2 是稀有的类固醇-苯丙烷杂交的新成员。化合物 5 对 HT29 细胞具有显著的细胞毒性，IC₅₀ 值为 5.8 μM。化合物 8 对 RAW264.7 中 NO 的产生具有显着抑制作用，IC₅₀ 值为 2.7 μM，通过在转录和蛋白水平以及 NF-κB 通路抑制 iNOS 水平。