New furoisocoumarins and isocoumarins from the mangrove endophytic fungus Aspergillus sp. 085242

The chemical investigation of the mangrove endophytic fungus sp. 085242 afforded eight isocoumarin derivatives - and one isoquinoline . Asperisocoumarins A and B ( and ) were new furoisocoumarins, and asperisocoumarins E and F ( and ) were new isocoumarins. Their structures were established by analysis of their spectroscopic data and the absolute configuration of compound was unambiguously determined by X-ray structure analysis and ECD calculation. Moreover, the absolute configurations of compounds - were assigned by comparison of their ECD spectra with isocoumarins described in the literature. Asperisocoumarins C and D ( and ) were fully characterized spectroscopically and isolated from a natural source for the first time. Asperisocoumarins A-D ( - ) related to the class of furo[3,2- ]isocoumarins are rarely occurring in natural sources. Compounds , , and showed moderate α-glucosidase inhibitory activity with IC of 87.8, 52.3, and 95.6 μM, respectively. In addition, compounds and exhibited weak radical scavenging activity with EC values of 125 and 138 μM, respectively.