Abstract: Four new compounds, asperisocoumarin G ( 1 ), asperisocoumarin H ( 2 ), (±)-asperisocoumarin I (±)- 3 , along with the known pergillin ( 4 ) and penicisochroman L ( 5 ) were isolated from a mangrove endophytic fungus Aspergillus sp. 085242 by further chemical investigation. The structures of the new compounds, including their absolute configurations, were established by analysis of HR-ESI-MS and NMR spectroscopic data, and ECD calculation. Asperisocoumarins G-I ( 1 − 3 ) were new isocoumarins belonging to the class of furo3, 2-hisocoumarins which are rarely found in natural sources. All of the isolated compounds were evaluated for their α-glucosidase inhibitory effects, and compounds 1 and 4 showed moderate α-glucosidase inhibitory activity, respectively. In an antimicrobial test, the racemate of 3 showed antibacterial activity against Salmonella.