New chromone compounds from the marine derived fungus Diaporthe sp. XW12-1

Four new chromone compounds diaporspchromanones A-C (1-3) and diaporspchromanone H (4), together with three known compounds (5-7) were separated from the marine derived fungus Diaporthe sp. XW12-1. The structures of the new compounds, including their absolute configurations, were elucidated by extensive spectroscopic analysis and the Mosher's ester method. Among them, diaporspchromanones A-C (1-3) possess a 3-substituted-chroman-4-one skeleton, which are rarely found in natural sources. In the bioassays, all compounds were evaluated for their inhibitory activity against lipopolysaccharide-activated nitric oxide (NO) production in RAW264.7 cells. Compounds 2 and 3 showed potent anti-inflammatory effects than the positive control (indomethacin, IC₅₀, 70.33 ± 0.95 μM) (p < 0.05) with IC₅₀ values of 19.06 ± 3.60 and 9.56 ± 0.18 μM, respectively.