Myromopholine A, a new unusual diketomorpholine from Myrothecium gramineum

A new diketomorpholine, myromopholine A (1), was isolated from the wetland fungus Myrothecium gramineum (ZLW0801-19). Through extensive spectroscopic analyses, including IR, MS, NMR, and X-ray single crystal diffraction, the planar structure and absolute configuration of the compound were determined, revealing the presence of a rare D-phenyllactic acid moiety. The investigation represents the first reported isolation of a diketomorpholine compound from the genus Myrothecium. Furthermore, it is the first identification of a diketomorpholine bearing a D-phenyllactic acid unit from a natural source, challenging the conventional understanding that such natural products exist exclusively as L-form derivatives.