Search

TheMyrtus nivelleiBatt. & Trab. is a shrub native to the Mediterranean and endemic to the central Sahara in the Hoggar massif of southern Algeria, whose leaves are used by the Tuareg, in infusion mixed with tea, against diarrhea, fever, diabetes and for its anti-infective properties. The hypoglycemic activity of the essential oil extracted from the leaves by hydrodistillation. has been demonstrated, with a significant decrease (P This drop in blood sugar was not observed in healthy rats treated with the essential oil. The essential oil did not improve the weight of the rats, nor their cholesterolemia. The antimicrobial activity of the essential oil has been studied for six microorganisms.Bacillus subtilisandCandida albicansare the most sensitive, they were inhibited from 2.5/1000 v/v. This oil is also active onStaphylococcus aureusat a concentration of 5/1000 v/v. This activity was weak againstEscherichia coliand absent againstPseudomonas aeruginosaand no activity was detected againstEnterococcus faecium. It would be interesting to combine these evaluations with chromatographic and spectral studies to determine the compounds responsible for these activities.

Background: The Algerian Saharan plants are plants of terrestrial origin, which during their evolution have adapted to the Algerian south ecosystem. By their particular ecological and evolutionary position, it is possible that these endemic plants also selected specific secondary metabolites with original chemical and biological characteristics. Objective: Phytochemical investigation of ethyl acetate and n-butanol extracts of M. nivellei leaves. Methods: Air-dried and coarsely powdered leaves were macerated with 80% methanol. The methanol extract diluted with distilled water was successively extracted with hexane, ethyl acetate and n- BuOH. The ethyl acetate and n-butanol extracts were fractionated by sephadex (LH-20) column using MeOH as eluent. Fraction 1 from ethyl acetate extract was chromatographed by preparative TLC to give pure compound (1). Fractions 4 and 5 from n-butanol extract were chromatographed by RPHPLC over a C18 column using MeOH/H2O (4:6, v/v) as solvent system. Fraction 4 gave compounds 3 (1.5 mg) and 4 (1.1 mg), fraction 5 gave compound 2 (5.5 mg). Structural elucidation was established by a combination of one- and two-dimensional NMR techniques, and mass spectrometry. Results: The investigation of ethyl acetate and n-butanol extracts of M. nivellei leaves allowed the isolation for the first time of Octabenzone (1) which was never reported before along with three known flavonols, myricetin 3-O-β-D-(6”-galloyl)galactoside (2), quercetin 3-O-β-D-(6”- galloyl)galactoside (3) and myricetin 3-O-arabinoside (4). Conclusion: These results suggested that the leaves of M. nivellei stand as a promising natural source for sunscreen products such as octabenzone. In combination with its richness of phenolic compounds, these observations lead us toward further studies concerning M. nivellei biological activity against skin damages and skin cancer.

This study aims to evaluate the chemical composition and biological effects of an endemic Algerian species Myrtus nivellei belonging to the Myrtaceae family. The aerial parts of the plant were submitted to hydrodistillation and analysed with gas chromatography - mass spectrometry (GC-MS). This oil was yielded 0,75% (w/w). The GC-MS revealed that 1,8 cineole is the most abundant component (53,44%) while other compounds were present in high contents: 2,2,6,7-tetramethyl-10-oxatricyclo [4.3.0.1(1,7)]- decan-5-one (11,73%), trans ocimene (7,54%), linalyl propirionate (6,81%) and lavandulyl acetate (5,24%). In addition ethanolic extract of studied plant was prepared. Total phenol, tannin, flavonoid, and condensed tannin?s contents were determined using Folin-Ciocalteu, aluminum chloride and vanillin colorimetric methods, respectively. Three tests were used for the investigation of antioxidant activity of both extract and oil. Strong antioxidant activity was shown mainly by crude extract. Antibacterial screening was evaluated against Gram positive and Gram negative bacteria. Ethanolic extract and oil were active especially against Staphylococcus aureus.

TheMyrtus nivelleiBatt. and Trab. is an endemic shrub of the central Sahara, known for its respiratory anti-infective and hypoglycemic properties. This work consists of a physicochemical, chromatographic and spectral analysis of essential oils extracted from leaves harvested in the region of Tamanrasset in southern Algeria. The extractive yield is 1.6 ± 0.05 (ml/100g of dry plant), the refractive index is 1.4700 ± 0.0005 and the relative density is 0.9052 (g/ml). GC-MS made it possible to inventory thirty-six (36) compounds: 78.55% of monoterpenes, essentially oxygenated, including 1,8-Cineole which represents the majority compound at 33.95%; which could partly explain the anti-infectious properties of Hoggar Myrtle essential oil.

Objective To study the phytochemical constituents and in vitro biological activities of hydromethanolic extract and fractions from Algerian Sahara Myrtus nivellei (M. nivellei) collected in Hoggar region and to identify the active fraction that can act as an alternative of commonly used antibiotics and as antileishmanial or antioxidant agents. Methods Phytochemical screening of M. nivellei aerial parts was realised according to the literature. Extract was firstly prepared by using aqueous methanol then fractionated with ethyl acetate and butanol solvents. Total phenolics, tannis and flavonoids, of the hydromethanolic extract and their fractions were determined by Folin–Ciocalteu method as gallic acid equivalents and by aluminium chloride as rutin equivalent respectively. Extract and fractions were tested for their antimicrobial and antiparasital activities against standard bacteria using agar diffusion method and two kinds of leishmania visceral and cutaneous. The antioxidant activities were realized using phosphomolybdenum, FRAP and DPPH tests. Results Preliminary phytochemical screening exhibited the presence of flavonoids, tannins, saponins, and alkaloids. The experimental results showed that plant extract and fractions were high in phenolic compounds and exhibited an important role as antioxidant, antimicrobial and had a moderate antileishmanial activity. Conclusions These observations lead us toward more studies in this field, so that we can get more benefits from our local Algerian medicinal plants.

International audience

In recent years products derived from plant biomass have become increasingly popular in many industries (aromatherapy, cosmetics, food, etc.). The aim of our study was twofold. First, it was to study the chemical composition of essential oils isolated from different species from Vietnam, adapting the analytical strategy to the complexity of the mixture. Secondly, we want to contribute to a better understanding of the volatiles by two species of the type Myrtus : M. nivellei, endemic in the Sahara, the chemical composition of the essential oil had never been previously described and M. communis, through the analysis of essential oils from different sources around the Mediterranean and their aroma. The first part concerns the essential oils of 7 species from Vietnam. Among these, the essential oils of Clausena indica, C. anisum-olens, Cunninghamia konishii, Asarum glabrum, A. cordifolium et Cupressus tonkinensis (EO stems) were analysed by GC(RI), GC-MS and 13C NMR, without prior splitting. In contrast, the essential oils of C. tonkinensis (EO leaves) and Xanthocyparis vietnamensis, more complex than the preceding, required one or more fractionation steps by short open column chromatography of silica prior to analysis by GC(RI), GC-MS and 13C NMR and sometines 2D NMR. This work has contributed to a better understanding of the chemical compositions of these essential oils and has enriched our NMR spectra library « Terpènes » of 8 compounds, two of which had never been identified or described in the literature: the 10-epi-nor-g-eudesmen-11-one and the 12-hydroxy-isodihydroagarofuran. The second and final part deals with essential oils of M. nivellei and of M. communis. The essential oil of leaves of M. nivellei was studied by combination of different techniques (CC, GC-MS, GC(RI), 13C NMR and 2D NMR). We identified 26 compounds representing 94.7% of the overall chemical composition, including the two major compounds are 1,8-cineole (37,5%) and limonene (25,0%). We managed to determine the structure of two new compounds: the 1-hydroxy-1-(3-methylbutoxy)-2-acetoxy-3,5,5-trimethyl-3-cyclopentene (4,3%) et le 1-hydroxy-1-(3-methyl-2-butenoxy)-2-acetoxy-3,5,5-trimethyl-3-cyclopentene (0,9%). Finally, the essential oils of M. communis (65 samples) from Corsica and other areas of the Mediterranean (Algeria, Portugal, Morocco, Tunisia and Sardinia) were analyzed by GC-MS, GC(RI) and 13C NMR, giving special importance to minority oxygenates. Four short chain esters, very rarely reported in the literature, have been systematically identified, regardless of the chemical group to which the essential oil belongs: the isobutyl isobutyrate, the isobutyl 2-méthylbutyrate, the 2-méthylbutyl isobutyrate and the 2-méthylbutyl 2-méthylbutyrate. Their individual contents vary from 0,1 to 2,2%. A sensory analysis has noted the contribution of these esters, with varying intensity, with a fruity top note from the essential oils of myrtle., Les produits issus de la biomasse végétale connaissent depuis quelques années un succès grandissant dans de nombreuses industries (aromathérapie, cosmétique, agroalimentaire, etc.). L’objectif de notre étude était double. D’une part, il s’agissait d’étudier la composition chimique d’huiles essentielles isolées à partir de différentes espèces originaires du Vietnam, en adaptant la stratégie analytique à la complexité du mélange. D’autre part, nous voulions contribuer à une meilleure connaissance des volatils produits par deux espèces du genre Myrtus : M. nivellei, espèce endémique au Sahara dont la composition chimique de l’huile essentielle n’avait jamais été décrite jusqu’alors et M. communis, à travers l’analyse d’huiles essentielles de différentes provenances du pourtour méditerranéen et leur aspect olfactif. La première partie concerne les huiles essentielles de 7 espèces originaires du Vietnam. Parmi celles-ci, les huiles essentielles de Clausena indica, C. anisum-olens, Cunninghamia konishii, Asarum glabrum, A. cordifolium et Cupressus tonkinensis (HE tiges) ont été analysées par CPG(Ir), CPG-SM et RMN 13C, sans fractionnement préalable. En revanche, les huiles essentielles de C. tonkinensis (HE feuilles) et Xanthocyparis vietnamensis, plus complexes que les précédentes, ont nécessité une ou plusieurs étapes de fractionnement par chromatographie sur colonne ouverte de silice avant analyse par CPG(Ir), CPG-SM et RMN 13C et parfois RMN 2D. Ce travail a ainsi contribué à une meilleure connaissance des compositions chimiques de ces différentes huiles essentielles et a permis d’enrichir notre bibliothèque de spectres de RMN « Terpènes » de 8 composés, dont deux n’avaient jamais été identifiés, ni décrits, dans la littérature : la 10-épi-nor-g-eudesmèn-11-one et le 12-hydroxy-isodihydroagarofurane. La deuxième et dernière partie est consacrée aux huiles essentielles de M. nivellei et de M. communis. L’huile essentielle de feuilles de M. nivellei a été étudiée par combinaison de différentes techniques (CC, CPG-SM, CPG(Ir), RMN 13C et RMN 2D). Nous avons ainsi identifié 26 composés représentant 94,7 % de la composition chimique globale, parmi lesquels les deux composés majoritaires sont le 1,8-cinéole (37,5 %) et le limonène (25,0 %). Nous sommes parvenus à déterminer la structure de deux nouveaux composés : le 1-hydroxy-1-(3-méthylbutoxy)-2-acétoxy-3,5,5-triméthyl-3-cyclopentène (4,3 %) et le 1-hydroxy-1-(3-méthyl-2-butènoxy)-2-acétoxy-3,5,5-triméthyl-3-cyclopentène (0,9 %). Enfin, les huiles essentielles de M. communis (65 échantillons) provenant de Corse et d’autres localités du bassin méditerranéen (Algérie, Portugal, Maroc, Tunisie et Sardaigne) ont été analysées par CPG-SM, CPG(Ir) et RMN 13C, en accordant une importance particulière aux composés oxygénés minoritaires. Quatre esters à chaîne courte, très rarement reportés dans la littérature, ont ainsi été systématiquement identifiés, quel que soit le groupe chimique auquel l’huile essentielle appartient : l’isobutyrate d’isobutyle, le 2-méthylbutyrate d’isobutyle, l’isobutyrate de 2-méthylbutyle et le 2-méthylbutyrate de 2-méthylbutyle. Leurs teneurs individuelles varient de 0,1 à 2,2 %. Une analyse sensorielle a permis de noter la contribution de ces esters, avec une intensité variable, à la note de tête fruitée des huiles essentielles de myrte.

In recent years products derived from plant biomass have become increasingly popular in many industries (aromatherapy, cosmetics, food, etc.). The aim of our study was twofold. First, it was to study the chemical composition of essential oils isolated from different species from Vietnam, adapting the analytical strategy to the complexity of the mixture. Secondly, we want to contribute to a better understanding of the volatiles by two species of the type Myrtus : M. nivellei, endemic in the Sahara, the chemical composition of the essential oil had never been previously described and M. communis, through the analysis of essential oils from different sources around the Mediterranean and their aroma.The first part concerns the essential oils of 7 species from Vietnam. Among these, the essential oils of Clausena indica, C. anisum-olens, Cunninghamia konishii, Asarum glabrum, A. cordifolium et Cupressus tonkinensis (EO stems) were analysed by GC(RI), GC-MS and 13C NMR, without prior splitting. In contrast, the essential oils of C. tonkinensis (EO leaves) and Xanthocyparis vietnamensis, more complex than the preceding, required one or more fractionation steps by short open column chromatography of silica prior to analysis by GC(RI), GC-MS and 13C NMR and sometines 2D NMR. This work has contributed to a better understanding of the chemical compositions of these essential oils and has enriched our NMR spectra library « Terpènes » of 10 compounds, two of which had never been identified or described in the literature: the 10-epi-nor--eudesm-11-one and the 12-hydroxy-isodihydroagarofuran. The second and final part deals with essential oils of M. nivellei and of M. communis. The essential oil of leaves of M. nivellei was studied by combination of different techniques (CC, GC-MS, GC(RI), 13C NMR and 2D NMR). We identified 26 compounds representing 94.7% of the overall chemical composition, including the two major compounds are 1,8-cineole (37,5%) and limonene (25,0%). We managed to determine the structure of two new compounds: the 1-hydroxy-1-(3-methylbutoxy)-2-acetoxy-3,5,5-trimethyl-3-cyclopentene (4,3%) et le 1-hydroxy-1-(3-methyl-2-butenoxy)-2-acetoxy-3,5,5-trimethyl-3-cyclopentene (0,9%). Finally, the essential oils of M. communis (65 samples) from Corsica and other areas of the Mediterranean (Algeria, Portugal, Morocco, Tunisia and Sardinia) were analyzed by GC-MS, GC(RI) and 13C NMR, giving special importance to minority oxygenates. Four short chain esters, very rarely reported in the literature, have been systematically identified, regardless of the chemical group to which the essential oil belongs: the isobutyl isobutyrate, the isobutyl 2-méthylbutyrate, the 2-méthylbutyl isobutyrate and the 2-méthylbutyl 2-méthylbutyrate. Their individual contents vary from 0,1 to 2,2%. A sensory analysis has noted the contribution of these esters, with varying intensity, with a fruity top note from the essential oils of myrtle., Les produits issus de la biomasse végétale connaissent depuis quelques années un succès grandissant dans de nombreuses industries (aromathérapie, cosmétique, agroalimentaire, etc.). L’objectif de notre étude était double. D’une part, il s’agissait d’étudier la composition chimique d’huiles essentielles isolées à partir de différentes espèces originaires du Vietnam, en adaptant la stratégie analytique à la complexité du mélange. D’autre part, nous voulions contribuer à une meilleure connaissance des volatils produits par deux espèces du genre Myrtus : M. nivellei, espèce endémique au Sahara dont la composition chimique de l’huile essentielle n’avait jamais été décrite jusqu’alors et M. communis, à travers l’analyse d’huiles essentielles de différentes provenances du pourtour méditerranéen et leur aspect olfactif.La première partie concerne les huiles essentielles de 7 espèces originaires du Vietnam. Parmi celles-ci, les huiles essentielles de Clausena indica, C. anisum-olens, Cunninghamia konishii, Asarum glabrum, A. cordifolium et Cupressus tonkinensis (HE tiges) ont été analysées par CPG(Ir), CPG-SM et RMN 13C, sans fractionnement préalable. En revanche, les huiles essentielles de C. tonkinensis (HE feuilles) et Xanthocyparis vietnamensis, plus complexes que les précédentes, ont nécessité une ou plusieurs étapes de fractionnement par chromatographie sur colonne ouverte de silice avant analyse par CPG(Ir), CPG-SM et RMN 13C et parfois RMN 2D. Ce travail a ainsi contribué à une meilleure connaissance des compositions chimiques de ces différentes huiles essentielles et a permis d’enrichir notre bibliothèque de spectres de RMN « Terpènes » de 10 composés, dont deux n’avaient jamais été identifiés, ni décrits, dans la littérature : la 10-épi-nor--eudesm-11-one et le 12-hydroxy-isodihydroagarofurane. La deuxième et dernière partie est consacrée aux huiles essentielles de M. nivellei et de M. communis. L’huile essentielle de feuilles de M. nivellei a été étudiée par combinaison de différentes techniques (CC, CPG-SM, CPG(Ir), RMN 13C et RMN 2D). Nous avons ainsi identifié 26 composés représentant 94,7 % de la composition chimique globale, parmi lesquels les deux composés majoritaires sont le 1,8-cinéole (37,5 %) et le limonène (25,0 %). Nous sommes parvenus à déterminer la structure de deux nouveaux composés : le 1-hydroxy-1-(3-méthylbutoxy)-2-acétoxy-3,5,5-triméthyl-3-cyclopentène (4,3 %) et le 1-hydroxy-1-(3-méthyl-2-butènoxy)-2-acétoxy-3,5,5-triméthyl-3-cyclopentène (0,9 %). Enfin, les huiles essentielles de M. communis (65 échantillons) provenant de Corse et d’autres localités du bassin méditerranéen (Algérie, Portugal, Maroc, Tunisie et Sardaigne) ont été analysées par CPG-SM, CPG(Ir) et RMN 13C, en accordant une importance particulière aux composés oxygénés minoritaires. Quatre esters à chaîne courte, très rarement reportés dans la littérature, ont ainsi été systématiquement identifiés, quel que soit le groupe chimique auquel l’huile essentielle appartient : l’isobutyrate d’isobutyle, le 2-méthylbutyrate d’isobutyle, l’isobutyrate de 2-méthylbutyle et le 2-méthylbutyrate de 2-méthylbutyle. Leurs teneurs individuelles varient de 0,1 à 2,2 %. Une analyse sensorielle a permis de noter la contribution de ces esters, avec une intensité variable, à la note de tête fruitée des huiles essentielles de myrte.

Ethnopharmacologic relevance Myrtus nivellei Batt. & Trab. (Myrtaceae) known as Sahara myrtle is appreciated by the Touaregs as medicinal plant. Infusion of leaves is employed against diarrhea and blennorrhea. Crushed leaves added to oil or to butter ointment have been traditionally used for the treatment of dermatosis. Aim of the study is to consider the traditional medicinal uses and the lack of scientific studies on their biological activities, the present study was designed to elucidate the chemical composition, the antifungal activity of its essential oils against fungi responsible for human infections, as well as, its cytotoxicity in the mammalian keratinocytes. Materials and methods Chemical analysis of Myrtus nivellei essential oil isolated by hydrodistillation of aerial parts (leaves and flowers), was carried out using a combination of chromatographic (CC, GC with retention indices) and spectroscopic techniques (MS, 13C NMR, 2D NMR). The antifungal activity was evaluated by using broth macrodilution methods for yeasts and filamentous fungi. Cytotoxicity was tested in HaCaT keratinocytes through the MTT assay. Results Ten samples coming from two localities of harvest were investigated. The chemical composition was largely dominated by 1,8-cineole (33.6–50.4%) and limonene (17.5–25.0%). The structure of two new compounds bearing the isoamylcyclopentane skeleton has been elucidated. The oil was more active against Cryptococcus neoformans with MIC of 0.16 μL/mL followed by dermatophytes, with MICs of 0.64 and 1.25 μL/mL. Furthermore, evaluation of cell viability showed no cytotoxicity in HaCaT keratinocytes at concentrations up to 1.25 µL/mL. Conclusions The composition of Myrtus nivellei oil differed from that of Myrtus communis. The structure of two di-nor-sesquiterpenoids has been elucidated. It was possible to find appropriate doses of Myrtus nivellei oil with both antifungal activity and very low detrimental effect on keratinocytes. These findings add significant information to the pharmacological activity of Myrtus nivellei essential oils, specifically to its antifungal properties, thus justifying and reinforcing the use of this plant in traditional medicine.

The identification of past glacial refugia has become a key topic for conservation under environmental change, since they contribute importantly to shaping current patterns of biodiversity. However, little attention has been paid so far to interglacial refugia despite their key role for the survival of relict species currently occurring in climate refugia. Here, we focus on the genetic consequences of range contraction on the relict populations of the evergreen shrub Myrtus nivellei, endemic in the Saharan mountains since at least the end of the last Green Sahara period, around 5.5 ka B.P. Multilocus genotypes (nuclear microsatellites and AFLP) were obtained from 215 individuals collected from 23 wadis (temporary rivers) in the three main mountain ranges in southern Algeria (the Hoggar, Tassili n'Ajjer and Tassili n'Immidir ranges). Identical genotypes were found in several plants growing far apart within the same wadis, a pattern taken as evidence of clonality. Multivariate analyses and Bayesian clustering revealed that genetic diversity was mainly structured among the mountain ranges, while low isolation by distance was observed within each mountain range. The range contraction induced by the last episode of aridification has likely increased the genetic isolation of the populations of M. nivellei, without greatly affecting the genetic diversity of the species as a whole. The pattern of genetic diversity observed here suggests that high connectivity may have prevailed during humid periods, which is consistent with recent paleoenvironmental reconstructions.

This work aims at evaluating the anti-inflammatory activity of an endemic species of the central sahara: Myrtus nivellei Batt & Trab. The methanolic extract of this plant was extracted by Soxhlet apparatus and concentrated under reduced pressure using a rotary evaporator. In the carrageenan-induced paw edema test, five different groups of mice were established and the extract was administered orally in three different doses. The dose of 400 mg/kg was able to reduce significantly the paw edema with a comparable effect to that observed with Diclofenac (positive control). This is the first report to demonstrate a significant anti-inflammatory activity of the methanolic extract prepared from Myrtus nivellei .