Ethyl acetate (EtOAc) fraction of the Inonotus obliquus (Hymenochaetaceae) significantly inhibited nitric oxide production in lipopolysaccharide (LPS)-induced murine BV2 microglial cells. A new triterpene, characterized as inonotusol H (1) was isolated from the EtOAc fraction using the bioactivity-guided fractionation together with four known triterpenes, inotodiol (2), trametenolic acid (3), inonotsutriols A (4), and inonotusol A (5). Among them, compounds 2-4 significantly reduced LPS-induced nitric oxide production to 4.5 ± 0.8, 47.4 ± 4.4, and 2.8 ± 1.7%, respectively, at a concentration of 30 μM.

中文翻译：

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桦褐孔菌新三萜的结构解析

Inonotus Obliquus (Hymenochaetaceae) 的乙酸乙酯 (EtOAc) 部分显着抑制脂多糖 (LPS) 诱导的小鼠 BV2 小胶质细胞中一氧化氮的产生。使用生物活性引导的分级分离法从 EtOAc 馏分中分离出一种新的三萜，其特征为inonotusol H (1) 以及四种已知的三萜、inotodiol (2)、trametenolic acid (3)、inonotsutriol A (4) 和inonotusol A ( 5）。其中，化合物 2-4 在 30 μM 的浓度下将 LPS 诱导的一氧化氮产生分别显着降低至 4.5 ± 0.8、47.4 ± 4.4 和 2.8 ± 1.7%。