Pestiorosins A–F, New Papulacandins Isolated from the Fungus Pestalotiopsis rosea YNJ21

Six previously unreported papulacandins, namely pestiorosins A–F (1–6), were isolated from the fermentation products of the fungus Pestalotiopsis rosea YNJ21 isolated from the fruitbody of Amanita exitialis. The structures of these compounds, along with a known compound called pestiocandin (7), were determined using MS, NMR data, and modified Mosher's method. All compounds exhibited significant antifungal activity against Candida albicans, with MIC values ranging from 0.06 to 2.00 μg/mL. In terms of cytotoxicity assays, compounds 3 and 6 demonstrated moderate inhibitory activity against human breast cancer MCF-7 cells with IC50 values of 24.50 and 16.83 μM, respectively. On the other hand, compound 7 displayed similar levels of inhibitory activity against mice microglial BV2 cells with an IC50 value of 24.51 μM.