Chrodrimanins K–N and Related Meroterpenoids from the Fungus Penicillium sp. SCS-KFD09 Isolated from a Marine Worm, Sipunculus nudus

Six new meroterpenoids, chrodrimanins K–N (1–4), including two uncommon chlorinated ones (1 and 2), and verruculides B2 (5) and B3 (6), as well as seven known ones (7–13), were isolated from the fermentation broth of Penicillium sp. SCS-KFD09 isolated from a marine worm, Sipunculus nudus, from Haikou Bay, China. The structures including the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data, X-ray diffraction analysis, and ECD spectra analysis along with quantum ECD calculations. In addition, the X-ray crystal structures and absolute configurations of two previously reported meroterpenoids, chrodrimanins F (9) and A (11), are described for the first time. Compounds 1, 4, and 7 displayed anti-H1N1 activity with IC50 values of 74, 58, and 34 μM, respectively, while compound 5 showed weak inhibitory activity against Staphylococcus aureus with an MIC of 32 μg/mL.