Naphthaquinones of Diospyros batocana.

Root bark of West African tree Diospyros batocana Hiern, Ebenaceae, was examined. On the basis of chromatographic and spectral analysis it was shown to contain the naphtaquinones 7-methyljuglone, 2-methylnaphthazarin, biramentaceone, rotundiquinone, mamegakinone, diospyrin, diosquinone, isodiospyrin and batocanone. This last compound proved to be the (-)-enantiomer of isodiospyrin-2', 3'-epoxide. The probable existence of beta-dihydrodiospyrin, of a batocanone isomer and of an isodiospyrin diepoxide in this material is mentioned. The partial synthesis of two isomeric isodiospyrin di-epoxides is described.