Talarolactone A, an Isocoumarin Derivative Fused with Dihydrothiophene with Selective Antimigratory Activity from the Endolichenic Fungus Talaromyces sp.

A 3,4-dihydroisocoumarin derivative fused with dihydrothiophene, talarolactone A (1), and two known compounds, terreusinone (2) and 4,6-dihydroxy-5-methylphthalide (3), were isolated from Talaromyces sp. associated with Xanthoparmelia angustiphylla. The structure of 1 was deduced from extensive spectroscopic data, electronic circular dichroism calculations, and X-ray diffraction analyses. A plausible biosynthetic pathway of 1 was further proposed. Compound 1 showed selective antimigratory activity in a wound-healing assay without appreciable cytotoxic activity.

Active Metabolites from Endolichenic Fungus Talaromyces sp.

The active metabolites investigation of Talaromyces sp. (strain No. MH551540) associated with Xanthoparmelia angustiphylla afforded one new δ-lactone, talaromycin A (1), together with six known compounds, clearanol A (2), 6-methylbiphenyl-3,3',4,5'-tetraol (3), desmethylaltenusin (4), ergone (5), ergosterol (6), and palmitic acid (7). The structures of these compounds were elucidated by a combination of spectroscopic-data interpretation and single-crystal X-ray diffraction analysis. The cytotoxicities of 1-7 and the antioxidant activities of 3 and 4 were also evaluated.