Two Rare α ‐Pyrone (=2 H ‐Pyran‐2‐one) Derivatives from Gentiana rhodantha Franchet

Two new rare α ‐pyrone (=2 H ‐pyran‐2‐one) derivatives, rhodanthpyrones A and B ( 1 and 2 , resp.), together with fourteen known compounds, 3 – 16 , were isolated from the whole plants of Gentiana rhodantha. The structures of these compounds were elucidated by spectroscopic analyses. This is the first report on the occurrence of α ‐pyrone derivatives in the genus Gentiana.