Zosteropenillines: Polyketides from the Marine-Derived Fungus Penicillium thomii

Twelve new polyketides, zosteropenillines A–L (1–12), together with known polyketide pallidopenilline A (13), were isolated from the ethylacetate extract of the fungus Penicillium thomii associated with the seagrass Zostera marina. Their structures were established based on spectroscopic methods. The absolute configuration of zosteropenilline A (1) as 4R, 5S, 8S, 9R, 10R, and 13S was determined by a combination of the modified Mosher’s method, X‐ray analysis, and NOESY data. Absolute configurations of zosteropenillines B–D (2–4) were determined by timedependent density functional theory (TD‐DFT) calculations of ECD spectra. The effect of compounds 1–3, 7, 8, 10, and 11 on the viability of human drug‐resistant prostate cancer cells PC3 as well as on autophagy in these cancer cells and inhibitory effects of compounds 1, 2, and 8–10 on NO production in LPS‐induced RAW 264.7 murine macrophages were examined.