A new pyrone derivative from an endophytic Aspergillus tubingensis of Lycium ruthenicum.

A new pyrone named 6-isovaleryl-4-methoxy-pyran-2-one (1), along with three known pyrone compounds, rubrofusarin B (2), asperpyrones A (3) and campyrone A (4), was isolated from fermentation of Aspergillus tubingensis in Lycium ruthenicum. Their structures were confirmed by spectroscopic techniques, such as IR, NMR and HRESI-MS. Compound 2 indicated strong inhibitory activity against Escherichia coli, with MIC value of 1.95 mu g/mL. [GRAPHICS] .