Six novel verrucosidin derivatives, namely, poloncosidins A-F (1-6), together with one known analogue (7), were isolated and identified from the deep-sea-derived fungus Penicillium polonicum CS-252, which was obtained from cold-seep sediments collected in the South China Sea at a depth of 1183 m. Their structures were mainly established on the basis of a detailed interpretation of NMR spectroscopic and mass spectrometric data. The relative and absolute configurations of compounds 1-6 were determined by ECD calculations and a DP4+ probability analysis. Compounds 1-5 represent the first examples of verrucosidins with a 2,5-dihydrofuran ring which is uncommon among the known analogues. These compounds exhibited inhibitory activities against several human and aquatic pathogens with MIC values ranging from 4 to 32 μg/mL.
Keywords: Penicillium polonicum; antimicrobial activity; deep-sea-derived fungus; structure elucidation; verrucosidin derivatives.