Merosesquiterpenoids and ten-membered macrolides from a soft coral-derived Lophiostoma sp. fungus.

One new merosesquiterpenoid, craterellin D (1), along with one known analog, craterellin A (2), and five known ten-membered macrolides, 3-7, were isolated from a soft coral-derived Lophiostoma sp. fungus. The absolute configuration of 1 was established based on biogenetic consideration with the co-isolated analog 2, whose configuration was determined by modified Mosher's method and single-crystal X-ray diffraction analysis using CuKα radiation. The absolute configuration of 3 was determined by X-ray diffraction analysis using CuKα radiation. Compounds 2 and 3 showed antibacterial activities against Bacillus cereus with a MIC value of 3.12 μM.