Composition and Chemical Variability of Cleistopholis patens Trunk Bark Oil from Côte d'Ivoire.

Abstract

The chemical composition of trunk bark oil from Cleistopholis patens (Benth.) Engl. & Diels, growing wild in Côte d'Ivoire, has been investigated by GC (FID) in combination with retention indices, GC/MS and 13 C-NMR. Moreover, one oil sample has been subjected to CC and all the fractions analyzed by GC (RI) and 13 C-NMR. In total, 61 components have been identified, including various sesquiterpene esters scarcely found in essential oils. 13 C-NMR was particularly efficient for the identification of a component not eluted on GC and for the quantification of heat-sensitive compounds. Then, 36 oil samples, isolated from trunk bark harvested in six Ivoirian forests have been analyzed. The content of the main components varied drastically from sample to sample: (E)-β-caryophyllene (0.4 - 69.1%), β-pinene (0 - 57%), α-phellandrene (0 - 33.2%), α-pinene (0.1 - 30.6%), β-elemol (0.1 - 29.9%), germacrene D (0 - 25.4%), juvenile hormone III (0 - 22.9%), germacrene B (0 - 20.6%) and sabinene (tr-20.3%). Statistical analysis, hierarchical clustering and principal components analysis, carried out on the 36 compositions evidenced a fair chemical variability of the stem bark oil of this species. Indeed, three clusters have been distinguished: the composition of group I (ten samples) was dominated by β-pinene and α-pinene, group II (nine samples) was represented by α-phellandrene and p-cymene and group III (16 samples) by β-elemol. A sample displayed an atypical composition dominated by (E)-β-caryophyllene.