Stephaochratidin A, a Rare Stephacidin-Asperochratide Hybrid with Ferroptosis Inhibitory Activity from the Deep-Sea-Derived Aspergillus ochraceus

One rare stephacidin-asperochratide hybrid, stephaochratidin A (1), was isolated from the deep-sea-derived Aspergillus ochraceusMCCC 3A00521. The relative structure of 1was determined by comprehensive analyses of its 1D and 2D NMR data as well as HRESIMS data. And the absolute configuration was unambiguously assigned by ECD calculations and the X-ray single-crystal diffraction analysis. Plausible biosynthetic pathway of 1was proposed. Stephaochratidin A (1) exhibited significant ferroptosis inhibitory activity with the EC50value of 15.4 μM by downregulating HMOX-1 expression and lipid peroxidation.