Belgique

This study focused on evaluating the seasonal effect onthe chemical composition and on the biological activities of essential oils hydrodistillated fromleaves, trunk bark and fruits of Zanthoxylum leprieurii(Z. leprieurii) over the months, describing the climatic conditions of specific seasonsof Côte d’Ivoire. Z. leprieuriiisa plant commonly used in traditional medicine.Besides, some of its metabolites have already shown antioxidant, antimicrobial, anticancer, cytotoxic, schistosomidal and antibacterialproperties1,2.Essential oils were hydrodistillatedfrom organs with a Clevenger-type apparatus and analyzedby gas chromatography-mass spectrometry (GC/MS). Essential oil of leaves weredominated by sesquiterpene and methylketones, such as tridecan-2-one,(E)-β-ocimene,β-caryophyllene, dendrolasin, undecane-2-oneandthymol.Fruitsessential oils were characterized by monoterpenes with β-myrcene, citronellol, geranial and methyl nerate. Essential oils of trunk bark were commanded by methylketones, as the main compoundsweretridecan-2 one, β-caryophyllene,α-humulene, tridecan-2-ol and(E,E)-farnesol..Results showed that the seasonal effect does not statistically impactthe chemical composition of essential oils hydrodistillated from the different organs of the plant. Besides, the essential oils investigated in this work have exhibited significant antioxidant, anti-inflammatory, insecticidal and moderate anti-plasmodialactivities. Those activities were related to some compounds identified in the essential oils. In conclusion,this investigation confirmed the high potential of Z. leprieuriifor a use in traditional medicin

Etude phytochimique et biologique de trois plantes du genre Zanthoxylum

Le genre Zanthoxylum (Rutaceae) regroupe des plantes connues pour leurs utilisations en médecine traditionnelle à travers le monde. En Côte d’Ivoire, neuf espèces ont été identifiées (Zanthoxylum atchoum, Z. leprieurii, Z. macrophilum, Z. mezoneurispinosum, Z. parvifoliolum, Z. psammophilum, Z. rusbescens, Z. gelletii et Z. zantoxyloides). Le genre Zanthoxylum comprend des plantes possédant plusieurs propriétés biologiques intéressantes (antioxydant, anti-inflammatoire, anticancéreuse, antifongique, antibactérienne, antitumoral et antimicrobienne etc.). La présente recherche porte sur trois espèces de Zanthoxylum recensées en Côte d’Ivoire : Z. leprieurii, Z. psammphilum et Z. mezoneurispinosum. Elle a pour but de valoriser ces plantes à travers leurs métabolites secondaires volatils et non volatils. La première espèce Z. leprieurii est beaucoup utilisée en médecine traditionnelle compte tenu de ses nombreuses propriétés biologiques. Cependant, à ce jour, pour les deux dernières espèces endémiques à la Côte d’Ivoire aucune utilisation traditionnelle n’est connue. L’insuffisance de connaissance surtout sur Z. psammophilum et Z. mezoneurispinosum, a conduit à la réalisation d’une étude phytochimique pour la détermination d’activités biologiques des constituants de divers organes (les feuilles, les écorces du tronc, les racines et les fruits) de ces plantes. Les analyses de la composition chimique des huiles essentielles et les propriétés biologiques des différents organes ont été réalisées. À partir d’une hydrodistillation avec un appareil de type Clevenger, les huiles essentielles ont été extraites et ensuite analysées par une chromatographie en phase gazeuse couplée à la spectrométrie de masse (CPG/SM). Pour l’espèce Z. leprieurii, une étude de l’effet de la saison sur la composition chimique des divers organes des huiles essentielles a été réalisée. L’analyse statistique des résultats obtenus a permis de distinguer trois classes. La première classe représentant la composition des HE des fruits est caractérisée par les monoterpènes dominés par le β-myrcène et le citronellol. La deuxième classe est celle de la composition chimique des HE des écorces avec une abondance en tridécan-2-one. La troisième classe est celle de la composition chimique des HE des feuilles dominées par le tridécan-2-one, le (E)-β-caryophyllène et le dendrolasin. Chez Z. psammophilum, les composés chimiques identifiés dans l’HE des écorces sont essentiellement caractérisés par les composés non-terpéniques et dominés par le tridécan-2-one. Cependant, les huiles essentielles des feuilles et des racines sont caractérisées par les méthylcétones et les sesquiterpènes respectivement. Les caractéristiques principales des huiles essentielles isolées de Z. mezoneurispinosum sont les monoterpènes dominés par l’α-pinène dans les parties aériennes, tandis que la partie souterraine est caractérisée par les sesquiterpènes dominées par le γ-élémène et le cyclosativène. Les huiles essentielles extraites des trois plantes ont des activités biologiques satisfaisantes. Ce sont les activités antioxydantes, anti-inflammatoires, insecticides et anti plasmodiales. De plus l’étude phytochimique des feuilles de Z. mezoneurispinosum réalisée par chromatographie sur colonne, chromatographie liquide à haute pression (CLHP) et par la résonance magnétique nucléaire (RMN) a permis d’isoler au total huit composés. Ils sont constitués de quatre alcaloïdes (1-hydroxy-3,4-diméthoxy-N-méthylacridone, chélérythrine, skimmianine et xanthoxoline), un triterpène (lupéol), un dérivé de l’acide cinnamique (méthyl 4-coumarate), un derivé de l’acide carboxylique (acide (E)-4-isobutylamino-4-but-enoïque) et un flavonoïde (4’-méthoxy-5,7-dihydroxyflavone ou acacétine). Les différents résultats indiquent que ces plantes peuvent être utiles à l’homme. En effet, une meilleure connaissance de la composition chimique des différentes huiles essentielles, de leurs activités biologiques et les composés isolés des feuilles de Z. mezoneurispinosum, peut favoriser une plus grande utilisation dans la parfumerie, l’alimentation, la cosmétique, la médecine, etcThe genus Zanthoxylum (Rutaceae) includes plants known for their uses in traditional medicine around the world. In Côte d'Ivoire, nine species have been identified (Zanthoxylum atchoum, Z. leprieurii, Z. macrophilum, Z. mezoneurispinosum, Z. parvifoliolum, Z. psammophilum, Z. rusbescens, Z. gelletii and Z. zantoxyloides). Zanthoxylum geniuscontains several plant exhibitingbiological properties (antioxidant, anti-inflammatory, anticancer, antifungal, antitumor and antimicrobial etc.). The present research focuses on three species of Zanthoxylum harvested in Côte d'Ivoire: Z. leprieurii, Z. psammphilum and Z. mezoneurispinosum. Its goal is to valorize these plants through their volatile and non-volatile secondary metabolites. The first species Z. leprieurii is extensively used in traditional medicine because of its numerous biological properties. However, to date, no traditional use is known for the last two species endemic to Côte d'Ivoire. The lack of knowledge, especially on Z. psammophilum and Z. mezoneurispinosum, led to the realization of a phytochemical study for the determination and confirmation of biological activities of the constituents of various organs (leaves, trunk bark, roots and fruits) of these plants. The analyses of the chemical composition of essential oils and the biological properties of the various organs were realized. From a hydrodistillation with a Clevenger-type apparatus, the essential oils are extracted and analyzed by gas chromatography coupled with mass spectrometry (GC/MS). For the Z. leprieurii species, a study of the effect of the season on the chemical composition of the various organs of the essential oils was carried out. The statistical analysis of the results obtained made it possible to group the chemical compositions into three classes. The first class is characterized by constituents from fruits dominated by β-myrcene and citronellol. The second class was composed by compounds extracted from bark with an abundance of tridecan-2-one. The last class includes tridecan-2-one, (E) β-caryophyllene and dendrolasin which are derived from essential oils extracted from the leaves. In Z. psammophilum, the chemical compounds extracted from the essential oil of the bark are mainly characterized by methylketones and dominated by tridecan-2-one. However, essential oils from the leaves and roots are represented by methylketone and sesquiterpenes respectively. The main characteristics of essential oils isolated from Z. mezoneurispinosum are monoterpenes (α-pinene) in the aerial parts, while the underground part has an abundance of sesquiterpenes (γ-elemene and cyclosativene). The essential oils extracted from the three plants have satisfactory biological activities. These are antioxidant, anti-inflammatory, insecticidal and anti-plasmodial activities. In addition, the phytochemical study of the leaves of Z. mezoneurispinosum carried out by column chromatography, high pressure liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) allowed the isolation of a total of eight compounds. They consist of four alkaloids (1-hydroxy-3,4-diméthoxy-N-méthylacridone, chelerythrin, skimmianine and xanthoxoline), one triterpene (lupeol), a cinnamic acid derivative (methyl 4-coumarate), a carboxylic acid derivative ((E)-4-isobutylamino-4-butenoic acid) and a flavonoid (4'-methoxy-5,7-dihydroxyflavone or acacetine). The different results indicate that these plants can be useful to human. Indeed, a better knowledge of the chemical composition of the different essential oils, their biological activities and their isolated compounds, can promote greater use in perfumery, food, cosmetics, medicine, etcValorisation des plantes médicinales de Côte d'Ivoir

New essential oils with interesting biological activities from endemic plants of Côte d'Ivoire: Zanthoxylum mezoneurispinosum and Zanthoxylum psammophilum

New essential oils with interesting biological activities from endemic plants of Côte d’Ivoire: Zanthoxylum mezoneurispinosum (Ake Assi) and Zanthoxylum psammophilum (Ake Assi). Evelyne A. Tanoh1*, Fatimata Nea1, Tierry K. Kenne2, Manon Genva2, Matthew Saive2, Felix Z. Tonzibo1, Marie-Laure Fauconnier2. 1 Laboratory of Biological Organic Chemistry, UFR-SSMT, University Felix Houphouet-Boigny, BPV 34 Abidjan, Côte d’Ivoire 2 Laboratory of Natural Molecules Chemistry, University of Liège, Gembloux Agro- Bio Tech, 2, Passage of Deportés, B-5030 Gembloux, Belgium According to OMS nearly 80% of the population depend on traditional medicine given the strong growth in the use of natural products from plants1. Many Rutaceae plants are already used in traditional medicine for their biological properties such as anticancer and antioxidant activities. Zanthoxylum mezoneurispinosum (Ake Assi) and Zanthoxylum psammophylum (Ake Assi) are endemic Rutaceae to Côte d’Ivoire. In order to determine if those plants could be used in medicine, the aim of this work was to evaluate the chemical composition and the biological activities of essential oils extracted from both plants. Essential oils of our plants isolated from the leaves, trunk bark and roots. Their chemical compositions were determined by GC-MS. In vitro biological properties were determined using two activities: Antioxidant and anti-inflammatory. The analysis of the essential oils of leaves, trunk bark and roots of Z. psammophylum exhibit the predominance of two unusual methyl ketones, 2-undecanone and 2-tridecanone in leaves and trunk bark. These compounds have biological properties according to the literature2. The root is rich in thymol. Z. mezoneurispinosum oil is rich in alpha pinene for leaves and trunk bark, while the root is rich in gamma-elemene and cyclosativene. Cyclosativene is known for its biological activities3. The essential oils of both plants showed in increasing order antioxidant value in the leaves, trunk bark and roots. A measure of anti-inflammatory activity was found to in decreasing order in the root, followed by leaves and trunk bark. These plants could constitute a source of active molecules for traditional medicine in Côte d'Ivoire. However, although these plants are endemic in this country, they are not abundant and it is necessary to limit and protect the distribution of nurseries to produce plants and reintroduce these species into their natural habitat. References 1- O.M.S, 2002. : Besoins et potentiel. N° 4. 6 p. 2- Saini Mukesh and al, (2014). J. Agric. Food. Chem, 62: 4342 – 4348. 3- Kang Min-Seung, Lee Hoi-Seon, (2018). Applied Biological chemistry 61 (6): pp 653 – 659

Antioxidant and Lipoxygenase Inhibitory Activities of Essential Oils from Endemic Plants of Côte d’Ivoire: Zanthoxylum mezoneurispinosum Ake Assi and Zanthoxylum psammophilum Ake Assi

Zanthoxylum mezoneurispinosum Ake Assi and Zanthoxylum psammophilum Ake Assi are species endemic to Côte d’Ivoire. In this study, we determined, for the first time, the composition and biological activities of essential oils obtained from each of these plants. Essential oils were obtained by hydrodistillation from different organs of each plant with a Clevenger-type apparatus and analyzed by gas chromatography–mass spectrometry (GC-MS). Thirty-four components, accounting for more than 99.9% of the overall composition, were identified in the oils. The Z. psammophilum leaf and trunk bark oils exhibited two unusual methylketones, undecan-2-one and tridecan-2-one, whereas the root oil was rich in thymol and sesquiterpenoids. The Z. mezoneurispinosum leaf and trunk bark oils were rich in monoterpenoids, whereas sesquiterpenoids were predominant in the root oil. These samples produced, for the first time, some new chemical profiles of essential oils. The oils’ antioxidant activities were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and ferric reducing antioxidant power (FRAP) assays. The results showed that the essential oil isolated from roots of Z. mezoneurispinosum had the highest antioxidant activity, which is in accordance with the high thymol content of that oil. We also determined the lipoxygenase inhibitory activities of the essential oils. The results showed that all of the tested oils displayed high and close lipoxygenase inhibitory activities.EOHUB project, grant number 600873-EPP-1-2018-1ES-EPPKA2-KA

Variability of essential oil composition and biological activities of Lantana rhodesiensis Moldenke from Côte d'Ivoire.

Lantana rhodesiensis Moldenke is an herb or small shrub under two meters tall which is often multi-stemmed 1. It is used in traditional medicine for several treatments like diabetes1, rheumatism2, and arterial hypertension3. The aim of the present study was to determine the variation in the chemical composition of essential oils of L. rhodesiensis from Côte d’Ivoire. It also aimed to evaluate the in vitro antioxidant and anti-inflammatory activities of essential oils. Essential oils were obtained by hydrodistillation from leaves, stems and fruits of L. rhodesiensis from two localities of Northern Côte d’Ivoire. Essential oil composition was determined by GC-MS. The study of the antioxidant activity of leave essential oils was carried out by the DPPH and FRAP method; the anti-inflammatory activity was evaluated by the inhibition of protein denaturation method. Results showed that the main constituents present in most essential oils extracted from leaves, fruits and stems were β-caryophyllene, α-copaene, δ-cadinene and α-humulene. However, thymol was the major component in three leave samples. The stem oils are also dominated by caryophyllene oxide or thymol. It may be concluded that the sesquiterpenes were the predominant molecules in all essential oil samples of L. rhodesiensis from Northern Côte d'Ivoire. The results of the biological activities carried out on the leave essential oil samples showed that these oils have antioxidant and anti-inflammatory activities. This study showed the interest of L. rhodesiensis for the treatment of rheumatism and diabetes in traditional medicine. L. rhodesiensis is a potential source for isolating new antioxidant and anti-inflammatory molecules. 1. Piero, N. M. et al. J Dev. Drugs 4, 2 (2015). 2. Ruffo CK, Birnie A, Tengnas B. Edible wild plants of Tanzania p418 (2002). 3. JeanBangou, M., Kiendrebeogo, M., Compaoré, M. & Coulibaly, A. Y. J. Biol. Sci. 11, 31–38 (2011)

Seasonal variation, yield composition and biological activities of essential oils from Lantana camara grown in Côte d’Ivoire

Lantana camara is a thorny shrub that goes from 2 to 5 m high. Its ripe fruits are blackish and its flowers are in various colors. It is used in traditional medicine to treat several diseases and has numerous properties that were chemically described such as antioxidant, antibacterial and cytotoxic activities. The aim of this work was to study the variations in L. camara essential oils composition during the vegetative cycle. Leaves, flowers, fruits and stems of L. camara were harvested in Bingerville (East Côte d'Ivoire) each month from June 2015 to June 2017. The essential oil was produced by hydrodistillation and then analyzed by GC-MS and RMN. The antioxidant, anti-inflammatory and insecticidal activities of leaf and flowers essential oils were also determined. Results showed that essential oils hydrodistillated from L. camara are dominated by sesquiterpenes such as β-caryophyllene and α-humulene. Some monoterpenes such as thymol, sabinene and α-pinene were also present. The oil yield was high during the flowering and fruiting period. According to the chemical composition of L. camara’s oil, there were no significant differences between both harvesting periods defined but there were significant differences from one organ to another. However, within one organ the chemical composition varies under the vegetative cycle. It was found that the proportion of thymol was higher during flowering and fruiting months. The essential oil of stems, flowers, and fruits were more concentrated in thymol than leaf’s oil. E-β-caryophyllene and α-humulene were found in all essential oils. However, their quantity and the thymol content were strictly inverted throughout the harvest period or vegetative cycle. In addition, the essential oil extracted from leaves and flowers of L. camara showed good antioxidant, anti-inflammatory and insecticidal activities

Seasonal effect on the chemical composition, insecticidal properties and other biological activities of Zanthoxylum leprieurii Guill. & Perr. essential oils

This study focused, for the first time, on the evaluation of the seasonal effect on the chemical composition and biological activities of essential oils hydrodistillated from leaves, trunk bark and fruits of Zanthoxylum leprieurii (Z. leprieurii), a traditional medicinal wild plant growing in Côte d’Ivoire. The essential oils were obtained by hydrodistillation from fresh organs of Z. leprieurii growing on the same site over several months using a Clevenger‐type apparatus and analyzed by gas chromatography‐mass spectrometry (GC/MS). Leaf essential oils were dominated by tridecan‐ 2‐one (9.00 ± 0.02–36.80 ± 0.06%), (E)‐β‐ocimene (1.30 ± 0.50–23.57 ± 0.47%), β‐caryophyllene (7.00 ± 1.02–19.85 ± 0.48%), dendrolasin (1.79 ± 0.08–16.40 ± 0.85%) and undecan‐2‐one (1.20 ± 0.03–8.51 ± 0.35%). Fruit essential oils were rich in β‐myrcene (16.40 ± 0.91–48.27 ± 0.26%), citronellol (1.90 ± 0.02–28.24 ± 0.10%) and geranial (5.30 ± 0.53–12.50 ± 0.47%). Tridecan‐2‐one (45.26 ± 0.96–78.80 ± 0.55%), β‐caryophyllene (1.80 ± 0.23–13.20 ± 0.33%), ‐humulene (4.30 ±1.09–12.73 ± 1.41%) and tridecan‐2‐ol (2.23 ± 0.17–10.10 ± 0.61%) were identified as major components of trunk bark oils. Statistical analyses of essential oil compositions showed that the variability mainly comes from the organs. Indeed, principal component analysis (PCA) and hierarchical cluster analysis (HCA) allowed us to cluster the samples into three groups, each one consisting of one different Z. leprieurii organ, showing that essential oils hydrodistillated from the different organs do not display the same chemical composition. However, significant differences in essential oil compositions for the same organ were highlighted during the studied period, showing the impact of the seasonal effect on essential oil compositions. Biological activities of the produced essential oils were also investigated. Essential oils exhibited high insecticidal activities against Sitophilus granarius, as well as antioxidant, anti‐inflammatory and moderate anti‐plasmodial properties.EOHUB project 600873‐EPP‐1‐2018‐1ES‐EPPKA2‐KA

Composition, Seasonal Variation and Biological Activities of Lantana camara essential oils from Côte d’Ivoire.

This work aims to study the variations in the composition of Lantana camara leaf, flower and stem essential oils over two years. L. camara organs were harvested in Bregbo (East Côte d'Ivoire) each month from June 2015 to June 2017. The essential oils were obtained by hydrodistillation and characterized by GC-MS and 13C NMR. Eighty-four compounds accounting for 84.4 – 99.1% of the essential oils have been identified. The essential oils hydrodistillated from L. camara are dominated by sesquiterpenes such as (E)-β-caryophyllene and α-humulene, which were found in all samples. Some monoterpenes such as thymol, sabinene and α-pinene were also present. Statistical analysis (principal component analysis and clustering) revealed a high variability in essential oil composition between the different organs and also within the studied periods as the thymol proportion was higher during flowering and fruiting months. In addition, the stem, flower, and fruit essential oils were more concentrated in thymol than the leaf essential oils. The proportions of (E)-β-caryophyllene and α-humulene were strictly inverted with the thymol proportion throughout the harvest period or vegetative cycle. The antioxidant, anti-inflammatory and insecticidal activities of leaves and flowers essential oils were also studied. Results showed that L. camara leaf and flower essential oils displayed high antioxidant, anti-inflammatory and insecticidal activities.EOHUB project 600873‐EPP‐1‐2018‐1ES‐EPPKA2‐KA