5-hydroxyramulosin, a new natural product produced by Phoma tropica, a marine-derived fungus isolated from the alga Fucus spiralis.

The fungus Phoma tropica was isolated from the inner tissue of the marine brown alga Fucus spiralis. After large-scale cultivation the fungus was investigated for its secondary metabolite content and found to contain the new natural product 5-hydroxyramulosin ( 1) together with 7-methoxycoumarin. Both structures were elucidated using spectroscopic methods, mainly 1D and 2D NMR, and in the case of 1, a single crystal X-ray diffraction analysis.