Ebenaceae extractives. Part III. Binaphthaquinones from Diospyros species

摘要: Diospyrin and isodiospyrin have been isolated from the bark of Diospyros mespiliformis. Isodiospyrin was also found in wood D. virginiana. is optically active and, like diospyrin, an unsymmetrical dimer 7-methyljuglone, two naphthaquinone moieties being coupled at C-6 C-8′. The elliptifolia contains betulin, lupeol, plumbagin (2-methyljuglone), another dimer, elliptinone, which isomeric with diospyrin isodiospyrin. Elliptinone has structure 6,6′-biplumbagin.