Jean Brice Boti

The present study reports, for the first time, the chemical composition of the leaf essential oil (LEO) from Aspilia rudis as well as its antioxidant and anti-inflammatory activities. Analysis combining GC(RI), GC-MS and ¹³C-NMR of 36 samples identified 58 compounds representing 96.7–99.3% of the whole composition. Statistical analyses revealed chemical variability in three clusters, each composed of samples from the same sampling site. Cluster I is dominated by germacrene D (27.2 ± 2.7%), α-pinene (24.0 ± 2.9%) and (E)-β-caryophyllene (13.1 ± 1.7%), cluster II by α-pinene (38.9 ± 2.4%) and germacrene D (19.1 ± 3.6%), while the prevalent compound of cluster III is α-pinene (51.9 ± 5.3%), followed by β-pinene (11.7 ± 1.7%) and germacrene D (10.7 ± 2.2%). The oil samples S10, S26 and S36 demonstrated antioxidant activity (DPPH: EC₅₀ = 43.8 ± 1.0, 28.5 ± 1.0 and 38.8 ± 1.0 µg/mL, respectively; ABTS: TEAC = 17.16 ± 0.70, 23.35 ± 1.32 and 18.76 ± 0.64 µmol TE/mg EO, respectively) and anti-inflammatory activity through the LOX inhibition assay (IC₅₀ = 34.9 ± 1.0, 32.1 ± 1.0 and 22.2 ± 1.0 µg/mL, respectively). The activities of A. rudis LEO may be related to its main compounds and thymol, all known for their various pharmacological and biological properties, and probably to synergistic effects.

This study aims at investigating the chemical composition of root, stem and leaf essential oils from Ivorian Synedrella nodiflora, with the root oil being described for the first time. Sixty, fifty-one and forty-nine constituents were, respectively identified in the root, stem and leaf oils using a combination of GC(RI), GC-MS and ¹³C-NMR analyses. They accounted for 95.6–97.3%, 92.6–97.6% and 93.3–98.8% of the total composition, respectively. The main components of the root oil samples were γ-curcumene, (E)-β-caryophyllene, α-curcumene and curcuphenyl acetate. Three stem oil samples (S1, S2a, S3) were dominated by myrcene and limonene, while the most abundant components of sample S2b were thymol, germacrene D and β-elemene. (E)-β-caryophyllene and germacrene D were the major compounds of the leaf oil. Hierarchical cluster and principal component statistical analyses were performed and confirmed that the location does not influence the chemical composition. Group I consisted of the seven leaf oil samples, group II consisted of four stem oil samples and group III consisted of three root oil samples. The root oil composition differed considerably from the stem and leaf oil composition due to the presence of curcumene derivatives as major constituents. The leaf oil showed significant amounts of (E)-β-caryophyllene and germacrene D, while the stem oil stood out for its high myrcene, limonene and thymol contents.

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 ¹³Carbon-Nuclear Magnetic Resonance (¹³C-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, IC₅₀: 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 ¹³C-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 IC₅₀ (0.020 ± 0.005 mg/mL) was slightly higher than the non-competitive lipoxygenase inhibitor NDGA IC₅₀ (0.013 ± 0.003 mg/mL), suggesting a significant in vitro anti-inflammatory potential.

This study aimed to investigate the chemical composition of the leaf essential oil from Ivoirian Isolona dewevrei. A combination of chromatographic and spectroscopic techniques (GC(RI), GC-MS and ¹³C-NMR) was used to analyze two oil samples (S1 and S2). Detailed analysis by repetitive column chromatography (CC) of essential oil sample S2 was performed, leading to the isolation of four compounds. Their structures were elucidated by QTOF-MS, 1D and 2D-NMR as (10βH)-1β,8β-oxido-cadin-4-ene (38), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (cis-germacrene D-8-ol) (52), 4-methylene-(7αH)-germacra-1(10),5-dien-8α-ol (trans-germacrene D-8-ol) (53) and cadina-1(10),4-dien-8β-ol (56). Compounds 38, 52 and 53 are new, whereas NMR data of 56 are reported for the first time. Lastly, 57 constituents accounting for 95.5% (S1) and 97.1% (S2) of the whole compositions were identified. Samples S1 and S2 were dominated by germacrene D (23.6 and 20.5%, respectively), followed by germacrene D-8-one (8.9 and 8.7%), (10βH)-1β,8β-oxido-cadin-4-ene (7.3 and 8.7), 4-methylene-(7αH)-germacra-1(10),5-dien-8β-ol (7.8 and 7.4%) and cadina-1(10),4-dien-8β-ol (7.6 and 7.2%). Leaves from I. dewevrei produced sesquiterpene-rich essential oil with an original chemical composition, involving various compounds reported for the first time among the main components. Integrated analysis by GC(RI), GC-MS and ¹³C-NMR appeared fruitful for the knowledge of such a complex essential oil.

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, ¹³C‐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 ¹³C‐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.

The investigation of the stem essential oil of Laggera pterodonta (DC.) Sch. Bip. ex Oliv. (Asteraceae) from Côte d’Ivoire was carried out, using a combination of chromatographic (GC-RI, CC, pc-GC) and spectroscopic (GC-MS, ¹³C NMR) techniques. This study led to the identification of fifty constituents of which two new natural compounds 7β,11β-epoxy-eudesman-4α-ol and 7α,11α-epoxy-eudesman-4α-ol. Their structures were elucidated by 1 D and 2 D NMR spectroscopy after pc-GC purifying. Finally, 98.9% of the whole composition of the oil was identified with a high amount of 2,5-dimethoxy-p-cymene (78.9%). The other significant components were α-humulene (6.2%), (E)-β-caryophyllene (1.7%), thymyl methyl oxide (1.7%), α-phellandrene (1.5%), p-cymene (1.2%), (3αH,4βH,6αH,1αMe)-1,6-epoxy-3-hydroxycarvotanacetone angelic acid ester (1.1%) and 10-epi-γ-eudesmol (1.0%).

The composition of root bark oil from Cleistopholis glauca Pierre ex Engler & Diels growing wild in Ivory Coast was investigated by GC (in combination with retention indices) and ¹³C NMR spectroscopy after partition of hydrocarbons and oxygenated compounds on silica gel. Thirty-one compounds have been identified. C. glauca produces a sesquiterpene-rich oil, patchoulenone (33.5%), cyperene (9.5%) and germacrene D (6.6%) being the main components. Special attention was paid to the identification and quantification of germacrene C (a heat-sensitive compound) and δ-elemene, which were achieved by a combination of GC(FID) and ¹³C NMR spectroscopy. The composition of C. glauca root bark and leaf oils differed drastically.

Introduction: In the course of on‐going work on the characterisation of aromatic plants from the Ivory Coast we investigated the composition of the root oil from Xylopia aethiopica.Objectives: The aim of this work was to investigate the chemical composition of X. aethiopica root oil and elucidate the structure of two new compounds.Methodology: Analysis of the essential oil was carried out using a combination of chromatographic (CC, GC with retention indices) and spectroscopic techniques (MS, ¹³C‐NMR, 2D‐NMR).Results: Twenty seven components, accounting for 95.6% of the whole composition, were identified including various compounds for which spectroscopic data were absent on commercial computerised MS libraries. Three compounds are reported for the first time as natural compounds and the structure of two new compounds, 4,4‐dimethyl‐2‐vinylcyclohexene and endo‐5‐methoxy‐3‐patchoulene, has been elucidated using extensive two‐dimensional NMR spectroscopy.Conclusion: The composition of X. aethiopica root oil is dominated by two dimethylvinylcyclohexene isomers. It differs drastically from the composition of leaf and fruit oils of the same plant. The combination of analytical techniques appeared crucial for a fruitful analysis. Copyright © 2012 John Wiley & Sons, Ltd.