Talaromyolides A-D and Talaromytin: Polycyclic Meroterpenoids from the Fungus Talaromyces sp. CX11

Talaromyolides A-D (1-4) and talaromytin (5) were isolated from a marine fungus Talaromyces sp. CX11. Their structures were unambiguously determined by nuclear magnetic resonance (NMR), mass spectrometry, X-ray crystallography experiments, and time-dependent density functional theory electronic circular dichroism calculations. Talaromyolides A and D represent two novel carbon skeletons. Talaromytin exhibits two slowly interconverting conformers in DMSO-d(6) and CH3OH-d(4) that were studied by temperature-dependent NMR experiments. Talaromyolide D exhibits potent antiviral activity against pseudorabies virus (PRV) with a CC50 value of 3.35 mu M.