Stereochemistry of hydroxy-bearing benzolactones: isolation and structural determination of chrysoarticulins A-C from a marine-derived fungus Chrysosporium articulatum

Three new benzolactone metabolites, chrysoarticulins A-C (1-3), were isolated from the culture broth of Chrysosporium articulatum, a marine-derived fungus collected from an unidentified dictyoceratid sponge collected off the coast of Gagu-do, Korea. Structurally, these novel compounds were determined to be benzolactones possessing a branched side chain based on combined spectroscopic analyses. The absolute configurations of the asymmetric carbon centers were determined by extensive chemical and spectroscopic analyses that provided more insights into the stereochemistry of hydroxy-bearing benzolactones. The new compounds exhibited weak cytotoxicity against the K562 and A549 cell lines, and 3 was more active than the other compounds. Compound 3 was also moderately active against sortase A, a bacterial transpeptidase.