Bioactive Sulfur-Containing Sulochrin Dimers and Other Metabolites from an Alternaria sp. Isolate from a Hawaiian Soil Sample

[Image: see text] Polluxochrin (1) and dioschrin (2), two new dimers of sulochrin linked by thioether bonds, were purified from an Alternaria sp. isolate obtained from a Hawaiian soil sample. The structures of the two metabolites were established by NMR, mass spectrometry data, and X-ray analysis. Metabolite 1 was determined to be susceptible to intramolecular cyclization under aqueous conditions, resulting in the generation of 2 as well as another dimeric compound, castochrin (3). An additional nine new metabolites were also obtained, including four new pyrenochaetic acid derivatives (8–11), one new asterric acid analogue (13), and four new secalonic acid analogues (14–17). Bioassay analysis of these compounds revealed 1–3 displayed antimicrobial and weak cytotoxic activities.