Depsidone and phthalide derivatives from the soil-derived fungus Aspergillus unguis PSU-RSPG199

Two new compounds including one phthalide (asperlide, 1) and one depsidone (aspersidone, 2) together with twelve known compounds were isolated from the soil-derived fungus Aspergillus unguis PSU-RSPG199. Known emeguisin A exhibited potent antibacterial activity against Staphylococcus aureus and methicillin-resistant S. aureus as well as strong antifungal activity against Cryptococcus neoformans, each with MIC values of 0.5 μg/mL. Additionally, known pilobolusate was strongly active against the human oral carcinoma (KB) cell line with an IC50 value of 4.5 μM. Interestingly, emeguisin A and pilobolusate were noncytotoxic against noncancerous (Vero) cell lines.