Ange Bighelli

Intraspecific chemical variability of the essential oil of Pistacia lentiscus L. from Corsica.

Abstract The composition of 105 samples of essential oil of individual plants of Pistacia lentiscus from Corsica was investigated by 13 C NMR and GC. Myrcene, limonene, terpinen-4-ol, α -pinene, β -pinene, α -phellandrene, sabinene, p-cymene and γ -terpinene, were found to be the main constituents. The results were submitted to cluster analysis and discriminant analysis which allowed three groups of essential oils to be distinguished with respect to the content of terpinen-4-ol/ α -pinene, limonene and myrcene.

Direct Identification and Quantitative Determination of Acidic and Neutral Diterpenes Using 13C-NMR Spectroscopy. Application to the Analysis of Oleoresin of Pinus nigra

We report a methodology that allows identification and quantitative detrmination of individual acidic and neutral diterpenes in natural mixtures, using the computer-aided analysis of their 13C-NMR spectra. The analytical procedure was validated on artificial mixtures and then applied to authentic oleoresins of Pinus nigra. Up to eleven diterpenes, which represented 63% of the total composition of the oleoresin, were identified and quantified without previous separation or derivatization.

Composition and chemical variability of the triterpene fraction of dichloromethane extracts of cork (Quercus suber L.)

Abstract Dichloromethane extracts were prepared from 38 samples of cork harvested in different locations of Corsica and Sardinia from individual trees of Quercus suber L. Friedelin, 3-α-hydroxyfriedelan-2-one, betulin, betulinic acid, β-sitosterol and sitost-4-en-3-one were identified and their molar percentages were calculated by 13C NMR spectroscopy, following a procedure recently developed by our group. The results were submitted to chemometric analysis (k-means and principal component analysis), which allowed three groups to be distinguished with respect to the content of friedelin, betulinic acid and 3-α-hydroxyfriedelan-2-one.

Composition of a volatile extract of Eryngium duriaei subsp. juresianum (M. Laínz) M. Laínz, signalised by the antifungal activity

The composition of a volatile extract of Eryngium duriaei subsp. juresianum, signalised by the antifungal activity (MIC values=0.16-0.32 μL mL(-1)) against several dermatophyte species (Trichophyton mentagrophytes, T. rubrum, Epidermophyton floccosum; T. verrucosum, T. mentagrophytes var interdigitale, Microsporum canis and M. gypseum) was established following a combined methodology of GC, GC-MS and an exclusive (13)C NMR technique that does not require prior isolation of compounds. Twenty-five components were identified accounting 84.6% of the whole composition. Major compound was found to be α-neocallitropsene (26.0%) although the dominance of caryophyllane derived compounds, the most probable responsible for the antifungal activity, namely isocaryophyllen-14-al (16.2%), 14-hidroxy-β-caryophyllene (13.4%), caryophyllene oxide (7.6%) and E-β-caryophyllene (6.3%).

Composition and variability of the essential oils of the leaves and berries from Juniperus navicularis

The compositions of the essential oils isolated from leaves and berries of Juniperus navicularis Gand., an endemic species from Portugal, were investigated by GC and GC–MS. Oils from representative samples of populations as well as from individual samples were studied. The oils consisted mainly of monoterpene hydrocarbons (67.1–88.0% and 61.7% for leaf and berry oils, respectively). α -Pinene (6.3–38.0%), limonene (7.0–34.6%), α -phellandrene (2.2–13.1%) and pcymene (4.8–10.3%) were the major constituents of the oils from leaves and β-myrcene (25.8%) and α -pinene (24.4%) the major ones of the oil from berries. No meaningful differences were observed comparing the composition of leaf oils from populations collected at distinct seasons but, within the same season, the range of variation of the major components suggests variability. Hierarchical clustering and principal component analysis (PCA) of the compositional data of the oils from individual samples confirms the variability allowing to establish two groups of essential oils differentiated by the content of the major constituents ( α -pinene, limonene, α -phellandrene and E-nerolidol) and the ratios α -pinene/limonene.  2002 Elsevier Science Ltd. All rights reserved.

Myrtus communis L. as source of a bioactive and safe essential oil

In Algeria, Myrtus communis L. is distributed throughout the Tell Atlas and the coastal regions of Algiers and Constantine. The leaves are used in respiratory disorders, diarrhea and hemorrhoids. The aims of this work were to evaluate the antifungal and anti-inflammatory potential of well characterized essential oils (EO). Since EO can be applied by inhalation, dermal application and oral administration, we used several mammalian cell lines to assess safe bioactive doses. The chemical composition of two samples was investigated by GC-FID, GC-MS and (13)C NMR spectroscopy. Monoterpene derivatives are the main compounds: α-pinene (50.8 and 33.6%), 1,8-cineole (21.9 and 13.3%), linalool (2.7 and 14.8%), and linalyl acetate (0.5 and 9.5%). The antifungal evaluation revealed that the oils were more active against Cryptococcus neoformans (yeast) and Epidermophyton floccosum, Microsporum canis, Trichophyton rubrum (dermatophytes). The anti-inflammatory potential was evaluated using an in vitro model of lipopolysaccharide (LPS)-stimulated macrophages. Assessment of cell viability was made through the MTT assay. Both oils were able to significantly inhibit NO production, without affecting cell viability, in concentrations up to 0.64 mg/mL. These promising results, disclose bioactive concentrations of Myrtle essential oils with a safety profile suggesting a potential oral and topical application or use by inhalation.

Artemisia vulgaris L. from Vietnam: Chemical Variability and Composition of the Oil Along the Vegetative Life of the Plant

Abstract Essential oils produced from a population of Artemisia vulgaris of Vietnamese origin cultivated near Hanoi were subjected to analysis by GC, GC/MS and 13C-NMR. The oils were found to contain oxygenated monoterpenes as major components (1,8-cineole, camphor and α-terpineol). The composition of these oils differed from that previously reported for Vietnamese A. vulgaris oil. Only slight differences in the composition of the oil were observed along the vegetative life of the plant. No significant difference was observed between compositions of leaf and flower oils. In addition, the combination of retention indices, GC/MS and 13C-NMR spectroscopy allowed the identification of unusual sesquiterpenes such as presilphiperfolan-9α-ol as a minor component.

Chemical Variability of Algerian Myrtus communis L.

The composition of 55 samples of essential oil isolated from the aerial parts of wild growing Myrtus communis L. harvested in 16 locations from East to West Algeria were investigated by GC (determination of retention indices) and 13C‐NMR analyses. The essential oils consisted mainly of monoterpenes, α‐pinene (27.4–59.2%) and 1,8‐cineole (6.1–34.3%) being the major components. They were also characterized by the absence of myrtenyl acetate. The compositions of the 55 oils were submitted to k‐means partitioning and principal component analysis, which allowed the distinction of two groups within the oil samples, which could be subdivided into two subgroups each. Groups I (78% of the samples) and II were differentiated on the basis of the contents of α‐pinene, linalool, and linalyl acetate. Subgroups IA and IB could be distinguished by their contents of α‐pinene and 1,8‐cineole. Subgroups IIA and IIB differed substantially in their contents of 1,8‐cineole and limonene. All the samples contained 3,3,5,5,8,8‐hexamethyl‐7‐oxabicyclo[4.3.0]non‐1(6)‐ene‐2,4‐dione (up to 4.9%).

New compounds, chemical composition, antifungal activity and cytotoxicity of the essential oil from Myrtus nivellei Batt. & Trab., an endemic species of Central Sahara

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, (13)C 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 0.16μL/mL followed by dermatophytes, with MICs of 0.64 and 1.25μL/mL. Furthermore, evaluation of cell viability showed no cytotoxicity in HaCaT keratinocytes at concentrations up to 1.25µL/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.

Direct Qualitative and Quantitative Analysis of Triterpenes Using 13C NMR Spectroscopy Exemplified by Dichloromethanic Extracts of Cork

We describe a methodology which allows identification and quantitation of individual triterpenes in natural mixtures, using the computer-aided analysis of their 13C NMR spectra, without previous separation. The analytical procedure was validated on artificial mixtures and applied to authentic extracts of cork. Identification of triterpenes was possible with the use of either reference spectra recorded in our laboratory or literature data.