Re-investigation of the anthraquinone pool of Rhamnus spp.: madagascin from the fruits of Rhamnus cathartica and R. intermedia.

As a continuation of our ongoing studies aimed at revealing the presence of oxyprenylated anthraquinones in plants belonging to the genus Rhamnus, in this paper we describe the extraction and HPLC separation of madagascin (3-isopentenyloxyemodin) from the fruits of R. cathartica L. and R. intermedia Steud. and Hochst. The title compound is described herein for the first time as a component of fruit extracts of Rhamnus species.