Ahmont Claude Landry Kablan

Irvingia gabonensis is a fruit tree native to West Africa. In Côte d'Ivoire, its trunk bark, leaves, and seeds are commonly used in traditional medicine and as food. While the fatty acid composition of the kernel has been studied extensively, the essential oil extracted from the trunk bark remains poorly documented. This study had two objectives: to characterize the chemical composition of this essential oil and to verify the reproducibility of the measurements. The oil was obtained by hydrodistillation and then analyzed by gas chromatography-mass spectrometry (GC/MS). The concentrations are expressed as mean ± standard deviation over several analytical replicates. Ten compounds were identified, representing 100.0% of the quantified constituents. The profile is dominated by hydrocarbon monoterpenes (94.7%). Sabinene is by far the most abundant (65.2 ± 1.26%), followed by p-cymene (8.7 ± 0.34%), γ-terpinene (7.8 ± 0.23%), and then α-pinene and α-terpinene (4.3% each). Oxygenated monoterpenes (4-carvomenthenol, 2.0%) and hydrocarbon sesquiterpenes (β-bisabolene, 3.3%) are present in smaller quantities. No oxygenated sesquiterpenes were detected. Standard deviations are low from one replicate to the next: the measurements show little dispersion under the experimental conditions used. A compound that alone exceeds 65% of the total suggests a sabinene a sabinene-dominant chemical profile for this bark, a profile comparable to those described in other West African organs and species rich in monoterpenes. These results provide an initial reference characterization of the essential oil from the bark of I. gabonensis from Côte d’Ivoire. They pave the way for broader studies on intraspecific variability: organs, localities, seasons.

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.

Two sterols namely β-sitosterol (1) and stigmasterol (2) were isolated from methanolic extract of the fruit barks of Coelocaryon klainei Pierre ex Heckel (Myristicaceae). They were isolated for the first time from this species. It is the first isolation of compounds in this genus Coelocaryon. The structures were elucidated on the basis of one and two-dimensional NMR, SM, IR and UV. Akoubet et al., International Current Pharmaceutical Journal, August 2017, 6(9): 49-52 http://www.icpjonline.com/documents/Vol6Issue9/01.pdf