Constituents of the Chinese crude drug "sāng-bái-pí" (Morus root bark).

From the benzene extract of the Chinese crude drug "Sāng-Bái-Pí" (Japanese name Sōhakuhi), the root bark of Morus sp. (Moraceae), a novel isoprene substituted flavanone, named sanggenon A, was isolated whose structure was shown to be I on the basis of spectral data. A known isoprene substituted flavone derivative, morusin (II), was also obtained from the extract.