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

ABSTRACT: The chemical investigation of the mangrove endophytic fungus Aspergillus sp. 085242 afforded eight isocoumarin derivatives 1-8 and one isoquinoline 9. Asperisocoumarins A and B (1 and 2) were new furoisocoumarins, and asperisocoumarins E and F (5 and 6) were new isocoumarins. Their structures were established by analysis of their spectroscopic data and the absolute configuration of compound 2 was unambiguously determined by X-ray structure analysis and ECD calculation. Moreover, the absolute configurations of compounds 3-5 were assigned by comparison of their ECD spectra with isocoumarins described in the literature. Asperisocoumarins C and D (3 and 4) were fully characterized spectroscopically and isolated from a natural source for the first time. Asperisocoumarins A-D (1-4) related to the class of furo[3,2-h]isocoumarins are rarely occurring in natural sources. Compounds 2, 5, and 6 showed moderate ?-glucosidase inhibitory activity with IC₅₀ of 87.8, 52.3, and 95.6 ?M, respectively. In addition, compounds 1 and 3 exhibited weak radical scavenging activity with EC₅₀ values of 125 and 138 ?M, respectively.

SUBMITTER: Xiao Z 

PROVIDER: S-EPMC5082600 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature