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

The UHPLC-HRMS analysis of basidiomata extract revealed that this mushroom accumulated elevated yields of an unreported specialized metabolite. The molecular formula of this unknown compound, CHO, indicated that a challenging structure elucidation lay ahead, owing to its critically low H/C atom ratio. The structure of this new isolate, namely ominoxanthone (), could not be solved from the interpretation of the usual set of 1D/2D NMR data that conveyed too limited information to afford a single, unambiguous structure.