Extensive phytochemical investigation of the polar constituents of Diospyros bipindensis Gürke traditionally used by Baka pygmies

The water maceration and methanolic extract of the stem barks of Diospyros bipindensis, which is a medicinal plant used in Cameroon by Baka pygmies, revealed a complex high-performance liquid chromatography (HPLC) profile primarily composed of coumarin and naphthoquinone glycosides. The methanolic and apolar extracts also exhibited significant antifungal activity on a TLC bioautography assay against Candida albicans. HPLC-microfractionation in 96-well plates combined with bioautography enabled the rapid localization of the antifungal compound that was identified by HPLC-PDA and HPLC-MS analysis as plumbagin. These on-line structural information were also used to dereplicate four known compounds. The isolation of the polar constituents from the methanolic extract enabled the identification of eleven other compounds also present in the traditional preparation, nine of which are reported for the first time. The structures of those compounds were elucidated by UV, NMR and HR-MS analysis.