Sterehirsutynes A - C: three new acetylenic aromatic metabolites from Stereum hirsutum .

Three new acetylenic aromatic compounds, sterehirsutynes A-C ( 1 - 3 ), along with three known congeners, frustulosinol ( 4 ), vibrayne ( 5 ), and sterehirsutinol ( 6 ), were isolated from the culture broth of Stereum hirsutum . Their structures were determined by detailed analyses of NMR and high-resolution mass. Chiral column analysis showed that compounds 2 and 3 were racemic mixtures. These new compounds were evaluated for porcine pancreatic lipase (PPL) inhibitory activities, and compounds 1 and (±) 3 showed moderate inhibitory activity against PPL, with IC 50 values of 23.2 ± 1.04 and 21.8 ± 2.15 μM, respectively.