Search

The variability of chemical composition of the leaf essential oil (EO) from Neuropeltis acuminata , a climbing liana growing wild in Ivory Coast, was investigated for the first time. The in vitro anti-inflammatory activity was also evaluated. Thirty oil samples were isolated from leaves collected in three forests of the country and analyzed using a combination of Column Chromatography (CC), Gas Chromatography with Retention Indices (GC(FID)), Gas Chromatography-Mass Spectrometry (GC-MS), and 13 Carbon-Nuclear Magnetic Resonance ( 13 C-NMR). Fractionation by CC led to the first-time isolation from natural source of δ-cadinen-11-ol, whose structural elucidation by one dimension (1D) and 2D-NMR spectroscopy is reported here. Finally, 103 constituents accounting for 95.7 to 99.6% of the samples' compositions were identified. As significant variations of the major constituents were observed, the 30 oil compositions were submitted to hierarchical cluster and principal components analyses. Five distinct groups were evidenced: Group I, dominated by ( E )-β-caryophyllene, kessane, and δ-cadinene, while the main constituents of Group II were germacrene B, ledol, α-humulene, ( E )-γ-bisabolen-12-ol, and γ-elemene. Group III exhibited guaiol, germacrene D, atractylone, ( E )-γ-bisabolen-12-ol, δ-cadinene and bulnesol as main compounds. Group IV was dominated by ( E )-nerolidol, guaiol, selina-4(15),7(11)-diene and bulnesol, whereas ( E )-β-caryophyllene, α-humulene and α-muurolene were the prevalent compounds of Group V. As the harvest took place in the same dry season in the three forests, the observed chemical variability could be related to harvest sites, which includes climatic and pedologic factors, although genetic factors could not be excluded. The leaf oil sample S24 behaved as a high inhibitor of LipOXygenase (LOX) activity (half maximum Inhibitory Concentration, IC 50 : 0.059 ± 0.001 mg mL -1 ), suggesting an anti-inflammatory potential.

The chemical variability and the in vitro anti-inflammatory activity of the leaf essential oil from Ivorian Isolona dewevrei were investigated for the first time. Forty-seven oil samples were analyzed using a combination of CC, GC(RI), GC-MS and 13 C-NMR, thus leading to the identification of 113 constituents (90.8-98.9%). As the main components varied drastically from sample to sample, the 47 oil compositions were submitted to hierarchical cluster and principal components analyses. Three distinct groups, each divided into two subgroups, were evidenced. Subgroup I-A was dominated by ( Z )-β-ocimene, β-eudesmol, germacrene D and ( E )-β-ocimene, while (10βH)-1β,8β-oxido-cadina-4-ene, santalenone, trans -α-bergamotene and trans -β-bergamotene were the main compounds of Subgroup I-B. The prevalent constituents of Subgroup II-A were germacrene B, ( E )-β-caryophyllene, (5αH,10βMe)-6,12-oxido-elema-1,3,6,11(12)-tetraene and γ-elemene. Subgroup II-B displayed germacrene B, germacrene D and ( Z )-β-ocimene as the majority compounds. Germacrene D was the most abundant constituent of Group III, followed in Subgroup III-A by ( E )-β-caryophyllene, (10βH)-1β,8β-oxido-cadina-4-ene, germacrene D-8-one, and then in Subgroup III-B by ( Z )-β-ocimene and ( E )-β-ocimene. The observed qualitative and quantitative chemical variability was probably due to combined factors, mostly phenology and season, then harvest site to a lesser extent. The lipoxygenase inhibition by a leaf oil sample was also evaluated. The oil IC 50 (0.020 ± 0.005 mg/mL) was slightly higher than the non-competitive lipoxygenase inhibitor NDGA IC 50 (0.013 ± 0.003 mg/mL), suggesting a significant in vitro anti-inflammatory potential.

The chemical composition of 44 leaf oil samples of Laggera pterodonta (DC.) Sch.Bip. ex Oliv. (Asteraceae) from Côte 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, α-humulene and (E)-β-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-γ-eudesmol and eudesm-7(11)-en-4α-ol for Group II. All the samples collected in Eastern Côte d'Ivoire constituted Group I, while samples collected in the Central area of the country constituted Group II., (© 2019 Wiley-VHCA AG, Zurich, Switzerland.)

Root and flower essential oils of Cyanthillium cinereum (L.) H. Rob. (Synonym Vernonia cinerea (L.) Less.) (Asteraceae) collected in Southern Côte d'Ivoire was investigated using a combination of chromatographic and spectroscopic techniques. The root oil composition was dominated by trans -β-bergamotene (20.7%), β-elemene (19.0%), cyperene (10.6%), germacrene A (7.1%) and β-pinene (3.8%), whereas γ-humulene (31.0%), ( E )-β-caryophyllene (17.0%), trans -β-bergamotene (7.7%), β-pinene (7.5%) and ( E )-β-farnesene (6.0%) were the major components of flower oil. Two new compounds bearing the trans -β-bergamotene framework were identified: trans -β-bergamotenone and ( E )- trans -β-bergamotenol.