Ominoxanthone—The First Xanthone Linearly Fused to a γ-Lactone from Cortinarius ominosus Bidaud Basidiomata. CASE- and DFT-Based Structure Elucidation

The structure of a new isolate, ominoxanthone, could not be solved from the interpretation of the usual set of 1D/2D NMR data, so a Computer-Assisted Structure Elucidation (CASE) workflow (Structure Elucidator Suite) was used to rank the different possible structure candidates consistent with the scarce spectroscopic data.