Coumestan glycosides from the stem bark of Cylicodiscus gabunensis

Abstract

Two new coumestan glycosides, coumestoside C (1) and coumestoside D (2), were isolated from the stem bark of Cylicodiscus gabunensis Harms. Their structures were established by spectroscopic means and chemical transformations as 9-O-α-L-rhamnopyranosyl-3-hydroxy-4-(5′-hydroxy-3′- methylbut-2′E-enyl) coumestan (1) and 9-O-β-D-galactopyranosyl-3-O- prenyl-4-hydroxycoumestan. Coumestoside C exhibited antimicrobial activity against Proteus vulgaris.