Psathrosterols C–E, highly conjugated ergosterol derivatives from Psathyrella rogueiana with anti-inflammatory and immunosuppressive activity

Three new ergosterols featuring with a highly conjugated ring system, psathrosterols C–E (1–3), have been isolated from the fungus Psathyrella rogueiana. The structures with the absolute configurations were elucidated by means of spectroscopic methods and single crystal X-ray diffraction. Compounds 1–3 exhibit inhibitory activity against NO production with IC50 values ranging from 8.4 to 21.8 μM. Compound 1 inhibits the LPS-induced proliferation of B lymphocyte cells with an IC50 value of 12.3 μM.