Pentaketides relating to aspinonene and dihydroaspyrone from a marine-derived fungus, Aspergillus ostianus

Three new pentaketides, aspinotriols A (1) and B (3) and aspinonediol (5), were isolated together with two known compounds, aspinonene (7) and dihydroaspyrone (9), from the marine fungus Aspergillus ostianus strain O1F313, which was collected in Pohnpei and cultured with bromine-modified artificial seawater. The structures of the new compounds were determined by spectroscopic analyses including I D and 2D NMR. Although 1 and 3 are diastereomers, they show nearly superimposable H-1 and C-13 NMR spectra. The absolute configurations of compounds 1, 3, 5, and 9 were elucidated by the modified Mosher's method.