Aromatic polyketides from marine algicolous fungi.

The investigation of the marine-derived fungi Acremonium sp. and Nodulisporium sp. led to the isolation of the new natural products acremonisol A ( 1) and (3 R)-7-hydroxy-5-methylmellein ( 2). Both fungi are endophytes of marine algae. Compounds 1 and 2 are biosynthetically related by both being aromatic pentaketides belonging to the dihydroisocoumarins. All structures were elucidated by extensive spectroscopic measurements.