A Neuroinflammation Inhibitor, Hypoxylon xanthone A, from Soil Fungus Hypoxylon sp.

Hypoxylon sp. was used to ferment at 25°C for 45 days. The solid culture of Hypoxylon sp. was extracted with 75% EtOH under ultrasonic for twice. And the dried combined extracts were then suspended in H2O and partitioned with ethyl acetate. EtOAc extracts were subjected to a silica gel column and eluted with petroleum ether - acetone to afford seven fractions. Sephadex LH-20 and RPHPLC were used subsequently to yield a novel xanthone metabolite (Hypoxylon xanthone A). Its structure was elucidated based on HR-ESI-MS, 1D-, 2D-NMR spectra, and the comparison of the experimental and calculated ECD spectra. The anti-neuroinflammatory assay of Hypoxylon xanthone A, as manifested by the inhibitory effect on LPS-induced NO production in BV-2 microglial cells, indicated almost the same inhibitory effect as minocycline in a dose-dependent manner within the concentration of 1-50 μM, suggesting that Hypoxylon xanthone A could be a new potential neuroinflammation inhibitor.