Montagnuphilones a-g, azaphilones from Montagnulaceae sp. DM0194, a fungal endophyte of submerged roots of Persicaria amphibia

Seven azaphilones, montagnuphilones A.G (1.7), together with previously known azaphilones 8.11, were encountered in Montagnulaceae sp. DM0194, an endophytic fungus isolated from submerged roots of Persicaria amphibia. The structures of 1.7 were elucidated on the basis of their MS and NMR spectroscopic analysis. Compounds 1.8 were evaluated for their cytotoxicity and ability to inhibit nitric oxide (NO) production in lipopolysaccharide-activated RAW264.7 macrophage cells. Among these, none were found to be cytotoxic to RAW264.7 cells up to 100.0 μM, but 8, 5, and 2 showed NO inhibitory activity with IC₅₀ values of 9.2 ± 0.9, 25.5 ± 1.1, and 39.6 ± 1.8 μM, respectively.