Jean-Claude Chalchat

QUALITATIVE AND QUANTITATIVE VARIATION IN MONOTERPENE CO-OCCURRENCE AND COMPOSITION IN THE ESSENTIAL OIL OF THYMUS VULGARIS CHEMOTYPES

Thymus vulgaris has a chemical polymorphism with six different chemotypes that show marked spatial segregation in nature. Although some populations have a single chemotype in majority, many have two or three chemotypes. In this study we analyze the quantitative variation among T. vulgaris populations in the percentage of oil composed of the dominant monoterpene(s) for each chemotype. In general, phenolic chemotypes (thymol and carvacrol), which occur at the end of the biosynthetic chain, have a significantly lower proportion of their oil composed of their dominant monoterpene than nonphenolic chemotypes (geraniol, α-terpineol, and linalool). This is due to the presence of high amounts of precursors (γ-terpinene and paracymene) in the oil of phenolic chemotypes. The essential oil of the nonphenolic thuyanol chemotype has four characteristic monoterpenes that together make up a lower proportion of the oil than the single dominant monoterpene of the other nonphenolic chemotypes. For all chemotypes, the percentage composition of the dominant monoterpene decreased significantly at sites where the chemotype is not the majority type. This decrease is correlated with a significant increase in either the proportion of the two precursors for the thymol chemotype or the monoterpenes characteristic of the other chemotypes at the site. The latter result suggests that a plant with dominant genes is responsible for the production of different monoterpenes can produce several molecules.

Comparative essential oil composition of flowers, leavesand stems of basil (Ocimum basilicum L.) used as herb.

The chemical composition of flower, leaves and stems from basil (Ocimum basilicum L.) have been examined by GC and GC-MS. The identified components constituting 99.03%, 95.04% and 97.66% of the flower, leaves and stem oils, respectively. The main constituents of the essential oil of flower, leaves and stem oils, respectively, were estragole (58.26%, 52.60% and 15.91%) and limonene (19.41%, 13.64% and 2.40%) and p-cymene (0.38%, 2.32% and 2.40%). Dill apiole (50.07%) was identified as the highest main constituent for stem. Estragole (15.91%), apiole (9.48) and exo-fenchyle acetate (6.14%) followed in order to decreasing them. Minor qualitative and major quantitative variations for some compounds of essential oils were determined with respect to different parts of O. basilicum. It was reported that the chemical composition of different parts oils of basil are very variable. It is known that specific estragole chemotypes are also known.

Correlation between chemical composition and antimicrobial activity. VI. Activity of some African essential oils.

Abstract The composition of thirteen essential oils of African origin (mostly Cameroon) were examined by GC and GC/MS. Oils of Xylopia aethiopica A. Rich.(Fruits), X. parviflora (A. Rich) Benth. (Fruits), Monodora myristica (Gaertn) Dunal (Fruits), M. brevipes Benth. (Seeds), Annona senegalensis Pers. (Fruits), Cananga odorata Hook. f. et Thomson (Fruits, Leaves), Tagetes minuta L. (Leaves, Flowers), Hernan-dia voyroni R. Cap. (Bark), Ageratum conyzoides L. (Leaves), Cymbopogon citratus (DC) Stapf (Leaves) and Aframomum citratum Pereira ex Oliv. et Hanb.) (Seeds) were included in this study. The major components of the oils were X. aethiopica: β-pinene (17.4%), sabinene (23.9%) and terpinen-4-ol (12.9%); X. parviflora: α-pinene (14.0%) and β-pinene (40.0%); M. myristica: α-phellandrene (48.8%) and α-pinene (15.9%); M. brevipes: α-phellandrene (74.9%), A. senegalensis; α-phellandrene (24.9%), α-pinene (11.9%) and myrcene (11.3%); C. odorata Fruits: α-pinene (11.1%), myrcene (24.7%) and sabinene (34.3%); C....

Study of clones of Salvia officinalis L. Yields and chemical composition of essential oil

The essential oil of Salvia officinalis L. in five selected clones of different origins (France, Hungary, Portugal, Romania, Czech Republic) was studied. Yields of oils from dried leaves were excellent (2–3%), and higher than those previously reported. The α:β-thujone ratio varied according to origin. Overall, some of the oils were of high quality in terms of their α- and β-thujone and camphor contents.

Essential Oils of Rosemary (Rosmarinus officinalis L.). The Chemical Composition of Oils of Various Origins (Morocco, Spain, France)

ABSTRACT The chemical composition of the essential oil of rosemary (Rosmarinus officinalis L.) from various geographical origins (Morocco, Spain and France) was determined by GC/MS. Although 48 constituents were identified, the oils of different origins could be differentiated based both on their physicochemical characteristics and their major components. The Spanish oils were found to be rich in α-pinene (19.4–24.7%), 1,8-cineole (19.0–21.8%) and camphor (16.3–18.9%), while the French oils possessed α-pinene (19.9–35.1%), 1,8-cineole (5.3–24.8%) and bornyl acetate (1.2–14.3%). Moroccan oils were typically rich in 1,8-cineole (43.5–57.7%).

Chemical composition and antifungal activity of rosemary (Rosmarinus officinalis L.) oil from Turkey

The essential oil of the aerial parts of Rosmarinus officinalis collected from Konya, Turkey was analysed by gas chromatography and gas chromatography–mass spectrometry. The oil yield of dried plant (volume/dry weight) obtained by hydrodistillation was 1.9%. Twenty compounds representing 99.93% of the oils were identified. The main constituents of the oils were p-cymene (44.02%), linalool (20.5%), γ-terpinene (16.62%), thymol (1.81%), β-pinene (3.61%), α-pinene (2.83%) and eucalyptol (2.64%). The oil consisted of monoterpenic hydrocarbons, oxygenated monoterpenes and sesquiterpene hydrocarbons. Also, the inhibition effect of rosemary oil was investigated against Alternaria alternata, Botrytis cinerea and Fusarium oxysporum. The experiment was carried out in vitro using disc diffusion to investigate the antifungal action of the oil. Oil tested on potato dextrose agar plates exhibited an inhibitory effect. The extent of inhibition of fungal growth varied depending on the levels of essential oil used in experiment.

Essential Oils of Myrtle (Myrtus communis L.) of the Mediterranean Littoral

Abstract The chemical compositions of 15 commercial samples of essential oils of leaves of Myrtus communis L. from five different Mediterranean locations (Corsica, Morocco, Tunisia, Lebanon, and former Yugoslavia) were studied. Forty-seven compounds were identified by GC/MS. They could be divided into two groups on the basis of their percentages of α-pinene; over 50% (Corsica and Tunisia), and under 35% (the others). The percentages of limonene, 1,8-cineole and myrtenyl acetate were consistent with this classification. The chemical compositions of these oils can be compared to those of Spanish oils.

Antifungal Activity of Selected Essential Oils, Cinnamaldehyde and Carvacrol against Malassezia furfur and Candida albicans

Abstract Effects of thyme oils extracted from nine Thymus vulgaris chemotypes, cinnamon oil (Cinnamomum zeylanicum), cinnamaldehyde and carvacrol were studied on growth of Malassezia furfur and Candida albicans. The last three substances and the carvacrol chemotype of thyme oil were the most efficient against the two yeasts. Yeast growth was monitored throughout eight days under log-step concentrations (1 μg/mL-1000 μg/mL) of these four substances. MICs (minimum inhibitory concentrations) and MLCs (minimum lethal concentrations) were also determined by two different methods: poisoned food and dilution-neutralization methods. MICs and MLCs values obtained by the former are lower than those determined by the latter. M.fitrfurwas observed to be more sensitive to cinnamon oil and cinnamaldehyde, while C. albicans was more sensitive to thyme oil and carvacrol. It was also found that essential oil activity is mainly due to their respective major components.

Essential Oil of Tagetes minuta from Rwanda and France: Chemical Composition According to Harvesting Location, Growth Stage and Part of Plant Extracted

ABSTRACT The chemical composition of the essential oils produced from Tagetes minuta which was harvested in Rwanda and France at various locations and growth stages, and isolated from different plant parts (flowers, leaves, seeds), was studied. The samples analyzed fell into four categories. Generally, (Z)-β-ocimene predominated in oil from flowers, and dihydrotagetone predominated in that from leaves. Tagetones and tagetenones occurred together or separately in large or small amounts. French oils differened from other oils by its preponderance of (Z)-tagetenone.

Morphological and Chemical Studies of Origanum Clones: Origanum vulgare L. ssp. vulgare

Abstract The National Conservatory of Medicinal, Aromatic and Industrial Plants at Milly-la-Foret, France, cloned 70 individual plants selected according to macromorphological criteria in 59 populations of diverse origins. They were described and compared in terms of 33 features using main component analysis (MCA). The chemical compositions of the oils isolated from each clone allowed a classification in six groups. The main components were respectively: sabinene, germacrene D, β-caryophyllene, cis-sabinene hydrate, terpinen-4-ol and hydrocarbon monoterpenes. No correlation could be found between morphological structure and chemical composition.