Fused multicyclic polyketides with a two-spiro-carbon skeleton from mangrove-derived endophytic fungus SCNU-F0002.

A pair of uncommon fused multicyclic polyketides with a two- spiro-carbon skeleton, (±)-isoepicolactone, (±)-1, and one new isobenzofuranone monomer (4), together with four other known biosynthetically related compounds were isolated from the fermentation of an endophytic fungus, SCNU-F0002, which was isolated from the fresh fruit of the mangrove plant . Comprehensive spectroscopic analysis, X-ray crystallography, together with calculated ECD, were employed to define the structures. The antibacterial and COX-2 inhibitory activities of the compounds (1-6) were evaluated. A possible biogenetic pathway of (±)-isoepicolactone was confirmed.