The Sterols and Dimeric Naphthoquinones of the Barks of Three West Africa Diospyros Species

Abstract

The stem barks of three west African species of Diospyros (Ebenaceae) have been examined. On the basis of spectral and Chromatographie analysis all three were shown to contain the sterols lupeol, betulin and betulinic acid. Diospyrin was shown to be the major naphthoquinone of D. cinnabarina and D, obliquifolia, accompanied in the latter by mamegakinone. In contrast D. bipindensis was found to contain mainly the conjugated naphthoquinone dimer diosindigo together with traces of isodiospyrin.