Naphthalenones from a <i>Perenniporia</i> sp. Inhabiting the Larva of a Phytophagous Weevil, <i>Euops chinesis</i>

The new naphthalenone derivatives perenniporides A–D (1–4) were isolated from solid cultures of a fungus Perenniporia sp. inhabiting the larva of Euops chinesis, a phytophagous weevil with high host specificity to the medicinal plant Fallopia japonica. The structures of 1–4 were elucidated primarily by NMR experiments, and 1 was confirmed by X-ray crystallography. The absolute configuration of 1 and 2 was assigned by electronic circular dichroism (ECD) calculations, whereas that of the C-10 tertiary alcohol in 3 was deduced via the CD data of the in situ formed [Rh2(OCOCF3)4] complex and supported by the ECD data. Compound 1 showed antifungal activity against five plant pathogens.