Curindolizine, an Anti-Inflammatory Agent Assembled via Michael Addition of Pyrrole Alkaloids Inside Fungal Cells

Curvularia sp. IFB-Z10, a white croaker-associated fungus, generates a skeletally unprecedented indolizine alkaloid named curindolizine (1), which displays an anti-inflammatory action in lipopolyssacharide (LPS)-induced RAW 264.7 macrophages with an IC50 value of 5.31 ± 0.21 μM. The enzymatic transformation test demonstrated that the unique curindolizine architecture was most likely produced by the regiospecific in-cell Michael addition reaction between pyrrole alkaloids, curvulamine, and 3,5-dimethylindolizin-8­(5H)-one.