A fungal strain, Pleosporales sp. CF09-1, was isolated from marine sediment collected from the Bohai Sea. A novel azaphilone derivative, named pleosporalone A (1), along with two known analogues, cohaerins A and B (2 and 3), were obtained and identified from the culture extract of Pleosporales sp. CF09-1. Their planar structures were elucidated by detailed analysis of spectroscopic data and by comparison with related known compounds. Pleosporalone A (1) represents the first azaphilone derivative characterised with A-ring aromatisation. Compound 1 showed strong antifungal activity against three plant pathogenic fungi Botrytis cinerea, Rhizopus oryzae and Phytophthora capsici with the MIC values of 0.39, 0.78 and 0.78 μM, respectively.
Keywords: Marine sediment; Pleosporales sp; antifungal activity; azaphilone derivative.