Chemotaxonomic significance of flavonoids, coumarins and triterpenes of Augusta longifolia (Spreng.) Rehder, Rubiaceae-Ixoroideae, with new insights about its systematic position within the family

Abstract

Augusta has traditionally been placed in the tribe Rondeletieae, subfamily Cinchonoideae. However, recent molecular phylogenies positioned it near to Wendlandia (Ixoroideae), but locate A. longifolia near to the clade Ixoroidinae II. The study of A. longifolia afforded two coumarins, five flavonoids, three triterpenoids and one benzoic acid derivative. These metabolites reinforce the separation of Augusta as a monospecific genus, and Lindenia as a genus of three species, closely related to Wendlandia.