Eremophilanolide sulfoxides and eremophilanolides from the mangrove fungus TBRC-BCC 64093

Abstract

Two unusual eremophilanolide sulfoxide diastereomers (1 and 2), seven eremophilanolides (3–7, 11, and 12) together with nine known eremophilanolides (8–10 and 13–18), anserinone A (19), and (−)-mellein-5-carboxylic acid (20) were isolated from the mangrove fungus TBRC-BCC 64093, a member of family Xylariaceae. The structures of these compounds were elucidated by extensive spectroscopic analysis of their NMR and MS data. The absolute configurations of the eremophilane sulfoxide diastereomers were determined by comparison of experimental and calculated electronic circular dichroism (ECD) data by TDDFT. Among the tested metabolites, eremophilane sulfoxide 1 showed weak cytotoxic activity against Vero cell lines with an IC50 value of 17.7 μg/mL.