Neuraminidase Inhibitors from the Fermentation Broth of Phellinus linteus

摘要

During a search for neuraminidase inhibitors derived from medicinal fungi, we found that the fermentation broth of Phellinus linteus exhibited potent neuraminidase inhibitory activity. Through bioassay-guided fractionation, two active compounds were purified from the ethyl acetate-soluble portion of the fermentation broth of P. linteus. These structures were identified as inotilone (>1) and 4-(3,4-dihydroxyphenyl)-3-buten-2-one (>2) by spectroscopic methods. Compounds >1 and >2 inhibited H1N1 neuraminidase activity with IC50 values of 29.1 and 125.6 µM, respectively, in a dose-dependent manner. They also exhibited an antiviral effect in a viral cytopathic effect reduction assay using MDCK cells. These results suggest that compounds >1 and >2 from the culture broth of P. linteus would be good candidates for the prevention and therapeutic strategies towards viral infections.