A new hydronaphthalenone from the mangrove-derived Daldinia eschscholtzii PSU-STD57.

One new hydronaphthalenone derivative (1) was isolated from the broth extract of the endophytic fungus Daldinia eschscholtzii PSU-STD57 together with five known compounds, isosclerone (2), 8-methoxy-1-naphthol, 1,8-dimethoxynaphthalene, 2,6-dihydroxyphenyl-1-butan-1-one and tyrosol. The structures were assigned by spectroscopic methods. All the compounds were tested for antimicrobial activity against Staphylococcus aureus, methicillin-resistant S. aureus and Microsporum gypseum.