Ilyomycin L, a novel resorcylic acid lactone with furan nucleus from Ilyonectria sp. DWS906

•12 resorcylic acid lactones were isolated from Ilyonectria sp.•The structure of compound 1 were assigned by spectroscopic and computational methods.•Cytotoxicity of the isolates against HCT116 cell line were evaluated.•Protective effects of the isolates on glutamate-induced injury in R28 cell line were examined. A novel resorcylic acid lactone with furan nucleus, ilyomycin L (1), along with eleven known analogues (2–12) were isolated from the fermentation of the soil-derived fungus Ilyonectria sp. DWS906. Their chemical structures were identified by the comprehensive spectroscopic methods, including 1D/2D NMR and HRESI mass spectra. The absolute configuration of 1 were determined by quantum chemical calculations of the 13C NMR data and electronic circular dichroism (ECD) spectra. The cytotoxicity of all the isolates against the human colorectal cancer HCT116 cell line, as well as their potential protective effects on glutamate-induced injury in the retinal precursor R28 cell line were examined.