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

Three new isocoumarinsdichlorodiaportintone (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 M, while compounds 1, 5, and 6 exhibited weak activities with IC50 values of 41.5, 33.6, and 67.2 M, 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 gmL(-1).