Dichloroisocoumarins with Potential Anti-Inflammatory Activity from the Mangrove Endophytic Fungus Ascomycota sp. CYSK-4

摘要

Three new isocoumarins—dichlorodiaportintone (>1), desmethyldichlorodiaportintone (>2) and desmethyldichlorodiaportinol (>3)—as well as six known analogues (>4–9) were isolated from the culture of the mangrove endophytic fungus Ascomycota sp. CYSK-4 from Pluchea indica. Their structures were elucidated by analysis of spectroscopic data. The absolute configuration of compounds >1 and >2 were determined by the modified Mosher’s method. Compound >2 showed significant anti-inflammatory activity by inhibiting the production of NO in LPS-induced RAW 264.7 cells with IC50 value of 15.8 μM, while compounds >1, >5, and >6 exhibited weak activities with IC50 values of 41.5, 33.6, and 67.2 μM, respectively. In addition, compounds >1, >5, and >6 showed antibacterial effects against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae, and Acinetobacter calcoaceticus with the MIC values in the range of 25–50 μg·mL⁻¹.