Acetylenic polyketides and a p-terphenyl derivative from the marine-derived fungus Microsphaeropsis arundinis P1B

One previously undescribed acetylenic polyketide, arunropsisol A (1), one new p-terphenyl derivative, aruterphenylol A (5), together with three known acetylenic polyketides, four benzene derivatives, and one macrolide, were isolated from the solid fermentation of the marine-derived fungus Microsphaeropsis arundinis P1B. Their structures were elucidated through a combination of spectroscopic, computational ECD, and X-ray diffraction methods. Arunropsisol A (1) is characterized by a novel carbon-skeleton, featuring a rare four-carbon 3-oxobut-1-yn-1-yl side chain, which suggests a biosynthetic relationship via oxidative cleavage of a common five-carbon isopentenyl-derived precursor. All isolated compounds were evaluated for their anti-inflammatory activity.