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 twelve isopentenyl benzene derivatives, including six previously undescribed ones, stereuins A–F. Their structures were established using interpretation of NMR and MS data, supplemented by comparison with the literature data. Stereuins A–C are unique benzoate derivatives containing fatty acids. Stereuins D and E feature a valylene group and a 6/6/6 ring system, respectively. In vivo, stereuin A significantly promoted neurite outgrowth. Several compounds exhibited antibacterial activity against Staphylococcus aureus. Specifically, stereuin F has an MIC50 value of 5.2 μg/mL against S. aureus, comparable to the positive control penicillin G sodium (1.4 μg/mL).

Keywords: Stereum hirsutum (Willd.) Pers., Stereaceae, Chemical investigation, Benzoate derivatives, Antibacterial activity, Neurite outgrowth-promoting activity