Composition of Xylopia aethiopica (Dunal) A. Rich essential oils from Cameroon and identification of a minor diterpene: ent-13-epi manoyl oxide

Xylopia aethiopica (Annonaceae) essential oil was extracted from fruits collected in four localities in Cameroon, and analysed by GC/MS and GC/FID. More than sixty compounds were identified with 47.5–84.0% of monoterpenes hydrocarbon, mainly b-pinene and b-phellandrene+1,8-cineole, 6.5–12.9% of oxygenated monoterpenes, 13.8–30.4% of sesquiterpenes, and 0.4–0.6 % of a minor unidentified diterpene. Trials of purification by column chromatography, followed by GC/MS and NMR analysis led to the identification of ent-13-epi manoyl oxide which is reported for the first time as a minor component in X. aethiopica essential oil