Paraconfuranones N–P, three new furanone polyketides with antibacterial activity from a marine-derived fungus Paraconiothyrium sporulosum DL-16

Abstract

Three new furanone derivatives, named paraconfuranones N–P (1–3) were obtained from an EtOAc extract of a marine-derived fungus Paraconiothyrium sporulosum DL-16. Their structures, including absolute configurations, were elucidated by extensive NMR spectroscopic and MS spectrometric analyses, modified Mosher's method, and ECD computational studies. Compounds 1–3 showed significant inhibitory activities against four strains of Gram-positive bacteria Staphylococcus aureus, and one strain of Gram-negative bacterium Vibrio parahaemolyticus, with MIC values ranging from 3.125 to 6.25 μg/mL, comparable to the positive controls, but none of them showed activity on the strains of Enterococcus faecalis, E. faecium, and Escherichia coli.