Composition and Intraspecific Chemical Variability of Leaf Essential Oil of Laggera pterodonta (DC.) Sch. Bip. ex Oliv. from Côte d’Ivoire

The chemical composition of 44 leaf oil samples of Laggera pterodonta (DC.) Sch.Bip. ex Oliv. (Asteraceae) from Cote d'Ivoire was investigated, using combination of chromatographic (GC-FID) and spectroscopic (GC/MS, (13) C-NMR) techniques. Two oil samples chosen according to their chromatographic profiles were submitted to column chromatography and all fractions of CC were analyzed by GC-FID, GC/MS and (13) C-NMR. In total, 83 components accounting for 96.5 to 99.4 % of the whole chemical composition were identified. Significant variations were observed within terpene classes: monoterpene hydrocarbons (0.4-22.7 %), oxygenated monoterpenes (32.9-54.9 %), sesquiterpene hydrocarbons (18.6-38.3 %) and oxygenated sesquiterpenes (3.5-38.4 %). Thus, the 44 compositions were subjected to hierarchical cluster analysis (HCA) and principal component analysis (PCA). Two groups were differentiated according to their composition. All the samples contained 2,5-dimethoxy-p-cymene, alpha-humulene and (E)-beta-caryophyllene among the main components. Other components were present at appreciable contents and allowed differentiation of two groups: sabinene and germacrene D for Group I; 10-epi-gamma-eudesmol and eudesm-7(11)-en-4alpha-ol for Group II. All the samples collected in Eastern Cote d'Ivoire constituted Group I, while samples collected in the Central area of the country constituted Group II.