Isolation, structural elucidation, and antimicrobial evaluation of the metabolites from a marine-derived fungus sp. ZZ1283.

A crude extract prepared from a culture of marine-sourced fungus ZZ1283 in the medium of potato dextrose broth was found to have antimicrobial activities. Chemical investigation on this active extract resulted in the isolation of eighteen metabolites, including purpuride D, a new analogue of drimane-type sesquiterpene lactones conjugated with -acetyl-L-valine. Structure of the new purpuride D was determined based on its HRESIMS data, NMR spectroscopic analyses, single-crystal X-ray diffraction and ECD calculation. Purpuride D showed activities in inhibiting the growth of methicillin-resistant , and with MIC values of 4, 3 and 8 μg/mL, respectively.