Triterpenes of Centaurea ptosimopappoides

Abstract

The roots of Centaurea ptosimopappoides afforded two new triterpenes; a new hopane derivative, 17 beta,21 beta-epoxy-16 alpha-ethoxyhopan-3 beta-ol and a new baccharane type triterpene, 3 beta-acetoxy-17,24-dioxo-baccharane. The known compounds, 17 beta,21 beta-epoxyhopan-3 beta-ol, 3 beta-acetoxyhop-17(21)-ene and 3 beta-acetoxy-erythrodiol were also isolated. In addition, the aerial parts yielded scopoletin, 7-oxositosterol, stigmasterol, alpha-amyrin and common sesquiterpene lactones of the genus Centaurea, 11,13-dihydro-desacetylcynaropicrin and cynaropicrin. The structures of the new compounds were determined by high field spectroscopic methods including 2D NMR techniques. (C) 1997 Elsevier Science Ltd.