Isolation and identification of oryzamutaic acids A and D from an Oryza sativa spontaneous mutant with yellow endosperm

Oryzamutaic acids A and D, alkaloids with a novel type of nitrogen-containing heterocyclic ring system, which had previously been isolated only from the brown rice (husked rice) of Hatsuyamabuki, an Oryza sativa artificial mutant cultivar with yellow endosperm, were isolated from the brown rice of Musashino 20, an Oryza sativa spontaneous mutant line with yellow endosperm. The concentrations of oryzamutaic acids A and D in the brown rice of Musashino 20 were similar to those of Hatsuyamabuki, respectively. These results suggest that oryzamutaic acid A may play an important role in the yellow color of the brown rice of Musashino 20.