Antifungal and Cytotoxic β‑Resorcylic Acid Lactones from a Paecilomyces Species

Eight new β-resorcylic acid lactones (RALs), including the hypothemycin-type compounds paecilomycins N–P (1–3) and the radicicol-type metabolites dechloropochonin I (4), monocillins VI (5) and VII (6), 4′-hydroxymonocillin IV (7), and 4′-methoxymonocillin IV (8), along with nine known RALs (9–17), were isolated from the cultures of Paecilomyces sp. SC0924. Compounds 1 and 2 feature a novel 6/11/5 ring system, and 3 is the first 5′-keto RAL. The structures of 1–8 were elucidated on the basis of extensive spectroscopic analysis, X-ray diffraction analysis, and theoretical calculations of ECD spectra. Compounds 3, 5, and 6 exhibit cytotoxicity against MCF-7, A549, and HeLa cells, and compounds 5 and 7 display antifungal activity against Peronophythora litchii.