Stereuins A–F: Isopentenyl benzene congeners with antibacterial and neurotrophic activities from Stereum hirsutum HFG27

Abstract

Cultivation and extraction of the fungus Stereum hirsutum (Willd.) Pers. yielded 12 isopentenyl benzene derivatives, including six previously undescribed derivatives, named stereuins A–F. Their structures were established based on NMR and mass spectroscopy analyses, supplemented by comparison with previously reported data. Stereuins A–C are unique benzoate derivatives containing fatty acid subunits. Stereuins D and E feature a valylene group and a 6/6/6 ring system. In vitro, stereuin A significantly promoted neurite outgrowth. Several compounds exhibited antibacterial activity against Staphylococcus aureus. Stereuin F has an IC₅₀ value of 5.2 μg/mL against S. aureus, comparable to the positive control, penicillin G sodium (1.4 μg/mL).