Faculty of Pharmaceutical Sciences and Chemical Analysis Center, Chiba University, 1-33 Yayoi, Inage, Chiba 263-8522, Japan.
Miroestrol (1) has been isolated previously as an active principle from "Kwao Keur" (Pueraria mirifica), a rejuvenating folk medicine from Thailand. Reinvestigation using bioassay-guided purification has resulted in the isolation of a new potent phytoestrogen, deoxymiroestrol (2). The facile aerial oxidation of 2 into 1 suggests the possibility that 1 may be an artifact.