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.

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