Essential oil composition of Eryngium rosulatum P.W. Michael ined.: A new undescribed species from eastern Australia

The essential oil composition from the aerial parts of a new Eryngium species from Australia, Eryngium rosulatum P.W. Michael ined., has been analysed by GC and GC/MS. A total of 34 compounds have been identified representing around 80% of the total oil. The main constituents of the oil were found to be β-elemene (16.0%) and bicyclogermacrene (12.5%). Other representative compounds were identified as δ-elemene (7.0%) and (E)-caryophyllene (5.9%). The sesquiterpene fraction (75.0%) was predominant in the essential oil of this species, most of these were hydrocarbons (53.8%). This paper represents the first study on this new, undescribed Australian species and its chemical composition.     

Chemical composition,intraspecies variation and seasonal variation in essential oils of Calendula arvensis L.

The essential oil composition of Calendula arvensis was established for the first time using GC and GC/MS. Eighty-five essential oil components were identified, which accounted for 90.3 g/100 g of essential oil. The oil contained a high concentration of sesquiterpenes, of which δ-cadinene and α-cadinol were the main components. The chemical composition of 25 Corsican C. arvensis oils was analyzed to determine intraspecies variation in essential oil composition. A matrix linking essential oil composition to sample location was composed to identify relationships between concentrations of volatile samples and the geographical origins of samples. Two main groups of compounds were identified according to the amount of sesquiterpenic compounds (hydrocarbons and alcohols) and soil characteristics. Seasonal variation (winter vs. spring) in the concentrations of two major compounds during the flowering period was observed.     

Chemical composition of the wood and leaf oils from the “Clanwilliam Cedar” (Widdringtonia cedarbergensis J.A. Marsh): A critically endangered species

Widdringtonia is the only genus of the 16 genera of Cupressaceae present in South Africa. This genus is represented by three species in South Africa; W. nodiflora, W. schwarzii and W. cedarbergensis (= W. juniperoides) and the latter listed as critically endangered. Cedarwood oil (generally obtained from Juniperus species) is widely used as a fragrance material in several consumer products, however, no data has been published on the volatiles of the Clanwilliam cedar (W. cedarbergensis) native to South Africa. The essential oil composition of the wood and leaf oil isolated by hydro-distillation were analysed by GC–MS. The two oils were distinctly different. Twenty compounds representing 93.8% of the total oil were identified in the leaf oil which was dominated by terpinen-4-ol (36.0%), sabinene (19.2%), γ-terpinene (10.4%), α-terpinene (5.5%) and myrcene (5.5%). Twenty six compounds representing 89.5% of the total were identified in the wood oil with the predominance of thujopsene (47.1%), α-cedrol (10.7%), widdrol (8.5%) and cuparene (4.0%).     

Relationship among some ecological factors and chemical composition of Ajuga chamaecistus Ging. plant species

Ajuga chamaecistus belongs to Lamiaceae plant family. Plant samples were collected from four habitats during vegetative and flowering periods for comparing the essential oil yield and composition. After drying, the essential oil was extracted by distillation method. Essential oil yields of plants in four habitats were calculated which the analysis and identification of essential oil composition was performed using GC and GC–MS. Ultimately, the PCA was used to determine the relationship between plant major components and environmental factors. The results showed that β-Pinene and Linalool compounds had the highest percentage of essential oil composition. Environmental factors including elevation, annual precipitation, mean annual temperature, annual evaporation, sand and clay content were identified as the most effective factors in the isolation of A. chamaecistus habitats. It appears that the difference between ecological and soil factors of four habitats can have a significant effect on the type and percentage of essential oil components.     

Variation in essential oil composition of Leonotis leonurus,an important medicinal plant in South Africa

Leonotis leonurus widely used by traditional healers in southern Africa for treatment of various ailments, is well known for its reported psychoactive properties. The present study was undertaken to investigate the variation in essential oil composition between geographically distinct populations of L. leonurus in South Africa using gas chromatography. Plant material (n = 50) was collected from three provinces of South Africa. Essential oils of the aerial parts were obtained by hydrodistillation and analysed using one and two dimensional gas chromatography. Twenty-six compounds accounted for more than 80% of the total composition of the oil. Eight major constituents in the oil, representing about 50% of the total oil composition, were identified by both GC–MS–FID and GCxGC–ToF–MS. These major compounds were trans-β-ocimene (0.1–5.0%), cis-β-ocimene (0.1–31.5%), β-caryophyllene (0.3–15.0%), caryophyllene oxide (0.1–5.0%), α-humulene (0.4–18.2%), γ-elemene (0.4–10.6%), α-cubebene (0.2–12.0%) and germacrene D (0.1–22.1%). Marked similarities exist in the essential oil composition between populations; differences are mostly quantitative when determined by GC–MS–FID, while GCxGC–ToF–MS data reveals both quantitative and qualitative differences.Untargeted multivariate analysis was performed using SIMCA-P + 14.0 PCA and OPLS-DA methods, identifying two distinct clusters, inland and coastal populations.     

Capitula essential oil composition of seven Centaurea species (sect. Acrocentron,Asteraceae) – Taxonomic implication and ecological significance

In this paper, we analyzed the capitula essential oil composition of seven Centaurea species, six of which belong to Centaurea calocephala complex, and the related species Centaurea melanocephala Pančić (subgenus Acrocentron, tribus Cardueae, subtribus Centaureinae) which inhabit Balkans Peninsula. The volatile organic compounds were extracted by simultaneous distillation extraction, using Likens-Nickerson type apparatus and the oils were analyzed by GC-FID and GC-MS. In total, 146 compounds were identified (95.5–99.4% of the total oil composition). The essential oils were dominated by sesquiterpenes (39.1–81.7%). The most abundant components were β-caryophyllene (3.1–28.3%), caryophyllene oxide (4.7–31.2%), germacrene D (2.9–22.2%), followed by n-hexacosane, [2Z,6E]-farnesol, eudesma-4(15),7-dien-1-β-ol, α-cadinole, germacrene B, trans-verbenol, and hexanal that were present in some samples in relatively high abundances. The geographic region and the color of capitula were analyzed in correlation with essential oil composition. Also, all investigated species are characterized by the different amount of most dominant components, which leads to the hypothesis that they “choose” different strategies: different combination and amounts of attractants for pollinators. Ecological correlations and taxonomical implications are further discussed.     

A comparative study of the essential oils of Cistus salviifolius in several populations of Crete (Greece)

The composition of the essential oils of fifteen populations of Cistus salviifolius L. (Cistaceae) from Crete (Greece) and their interpopulation variability was investigated by GC-MS. 167 compounds were identified representing an average of 96–100% of the oil composition. Labdane diterpenes were detected and identified in the essential oils of Cistus salviifolius L., for the first time. The results obtained from GC-MS analysis of the oils were submitted to a Principal Component Analysis (PCA). Three main chemotypes (clusters) were differentiated. All the essential oils were tested for their antimicrobial activity against Gram-positive and Gram-negative bacteria. Only chemotype III having camphor as a major constituent was active against Gram-positive bacteria. Camphor, viridiflorol, longiborneol, phyllocladene, abietatriene and cis-feruginol are the main constituents, while the group of oxygenated sesquiterpenes has the highest percentage composition.     

Chemical composition of essential oils of four Eucalyptus species and their phytotoxicity on silverleaf nightshade (Solanum elaeagnifolium Cav.) in Australia

Phytotoxicity and chemical composition of essential oils from four selected Eucalyptus species in Australia were investigated. Essential oils had stronger inhibitory effects on germination and seedling growth of silverleaf nightshade (Solanum elaeagnifolium Cav.) when compared with a commercial eucalyptus oil and with 1,8-cineole. E. salubris oil had the highest inhibition index for silverleaf nightshade germination, root growth and shoot growth, while E. spathulata had the lowest inhibitory effect except root growth. Gas chromatography-mass spectrometry analysis revealed 56 compounds present in E. salubris oil, with 1,8-cineole (57.6?%), ??-pinene (10.9?%) and p-cymene (8.3?%) predominant. E. dundasii oil contained 55 identified compounds with 1,8-cineole (65.5?%) and ??-pinene (19.9?%) being the richest fractions. There were 56 compounds identified from E. brockwayii oil with ??-pinene (31.1?%), isopentyl isovalerate (20.2?%) and 1,8-cineole (16.9?%) as the most abundant components. E. spathulata oil contained 60 compounds, predominantly 1,8-cineole (52.9?%) and ??-pinene (31.0?%). Further study is required to determine the phytoxicity of the individual identified compounds on silverleaf nightshade and whether the observed phytotoxicity is attributable to a single compound or to the synergistic effects of several compounds.     

Changes in secondary metabolite and biologically active compounds of Ajowan (Trachyspermum ammi L.) upon organic and conventional production systems

Ajowan is one of the most important medicinal species of the family Apiaceae, which has pharmacological properties for future research in drug development. The essential oil composition of this species in response to different sources of nitrogen and organic fertilizers has not been investigated yet, though the issue is of interest. The factorial combination of four nitrogen sources levels including control (no nitrogen source), urea (U), sulfur-coated urea (SCU), half of the sulfur-coated urea (1/2 SCU) + Alkazot Plus biological fertilizer) and organic fertilizers at four levels such as control (no organic sources), humic acid, vermicompost, half of vermicompost + humic acid) were laid out in a randomized completed block design (RCBD) in a field experiment. Results showed that the interaction between different sources of nitrogen and organic fertilizers on Ajowan essential oil percent and yield were significant (P < 0.01). The highest essential oil percent (5.5%) and essential oil yield (85.4 kg/ha) were obtained at control and Urea + vermicompost treatments. The results of essential oil analysis showed that seven compounds were identified in the ajowan oil, which are based on the highest amount included: Thymol, Gamma-terpinen, O-cymene, Alpha-terpineol propionat, Beta- pinene, Para-cymene, and Alpha pinene.     

GC/MS analysis and potential synergistic effect of mandarin and marjoram oils on Helicobacter pylori

Helicobacter pylori can cause chronic gastritis, peptic ulcer, and gastric carcinoma. This study compares chemical composition and anti-H. pylori activity of mandarin leaves and marjoram herb essential oils, and their combined oil. GC/MS analysis of mandarin oil revealed six compounds (100% identified), mainly methyl-N-methyl anthranilate (89.93%), and 13 compounds (93.52% identified) of marjoram oil, mainly trans-sabinene hydrate (36.11%), terpinen-4-ol (17.97%), linalyl acetate (9.18%), and caryophyllene oxide (8.25%)). Marjoram oil (MIC = 11.40 µg/mL) demonstrated higher activity than mandarin oil (MIC = 31.25 µg/mL). The combined oil showed a synergistic effect at MIC of 1.95 µg/mL (same as clarithromycin). In-silico molecular docking on H. pylori urease, CagA, pharmacokinetic and toxicity studies were performed on major compounds from both oils. The best scores were for caryophyllene oxide then linalyl acetate and methyl-N-methyl anthranilate. Compounds revealed high safety and desirable properties. The combined oil can be an excellent candidate to manage H. pylori.     

Glandular trichomes and essential oil characteristics of in vitro propagated <Emphasis Type="Italic">Micromeria pulegium</Emphasis> (Rochel) Benth. (Lamiaceae)

Main conclusion

In vitro conditions and benzyladenine influenced both content and composition of micropropagated Micromeria pulegium essential oils, with pulegone and menthone being the main essential oil components. The content and chemical composition of Micromeria pulegium (Rochel) Benth. essential oils were studied in native plant material at vegetative stage and in micropropagated plants, obtained from nodal segments cultured on solid MS medium supplemented with N⁶–benzyladenine (BA) or kinetin at different concentrations, alone or in combination with indole-3-acetic acid. Shoot proliferation was achieved in all treatments, but the highest biomass production was obtained after treatment with 10 μM BA. Phytochemical analysis identified up to 21 compounds in the essential oils of wild-growing and in vitro cultivated plants, both showing very high percentages of total monoterpenoids dominated by oxygenated monoterpenes of the menthane type. Pulegone and menthone were the main essential oil components detected in both wild-growing plants (60.07 and 26.85 %, respectively) and micropropagated plants grown on either plant growth regulator-free medium (44.57 and 29.14 %, respectively) or BA-supplemented medium (50.77 and 14.45 %, respectively). The percentage of total sesquiterpenoids increased in vitro, particularly owing to sesquiterpene hydrocarbons that were not found in wild-growing plants. Differences in both content and the composition of the essential oils obtained from different samples indicated that in vitro culture conditions and plant growth regulators significantly influence the essential oils properties. In addition, the morphology and structure of M. pulegium glandular trichomes in relation to the secretory process were characterized for the first time using SEM and light microscopy, and their secretion was histochemically analyzed.

     

Composition of volatile oils of Styrax (Styrax officinalis L.) leaves at different phenological stages

The volatile oil composition of Styrax officinalis L. leaves was investigated by GC and GC–MS during the phenological cycle of this species in a population growing wild in France. Whatever the analysed stage, yields were low 0.01–0.02%. (E)-2-hexenal, octanol and geraniol were the main constituents in all these volatile oils. The level of sesquiterpenoids was the highest at the vegetative stage. However, the chemical composition of leaf essential oil was relatively constant during the phenological stage of this tree and 58% of the identified compounds were common at all the analysed oils.     

Dittrichia graveolens (L.) Greuter Essential Oil: Chemical Composition,Multivariate Analysis,and Antimicrobial Activity

The chemical composition and in vitro antimicrobial activities of Dittrichia graveolens (L.) Greuter essential oil was studied. Moreover, using agglomerative hierarchical cluster (AHC) and principal component analyses (PCA), the interrelationships of the D. graveolens essential‐oil profiles characterized so far (including the sample from this study) were investigated. To evaluate the chemical composition of the essential oil, GC‐FID and GC/MS analyses were performed. Altogether, 54 compounds were identified, accounting for 92.9% of the total oil composition. The D. graveolens oil belongs to the monoterpenoid chemotype, with monoterpenoids comprising 87.4% of the totally identified compounds. The major components were borneol (43.6%) and bornyl acetate (38.3%). Multivariate analysis showed that the compounds borneol and bornyl acetate exerted the greatest influence on the spatial differences in the composition of the reported oils. The antimicrobial activity against five bacterial and one fungal strain was determined using a disk‐diffusion assay. The studied essential oil was active only against Gram‐positive bacteria.     

Genetic and Metabolite Diversity of Sardinian Populations of Helichrysum italicum

Background

Helichrysum italicum (Asteraceae) is a small shrub endemic to the Mediterranean Basin, growing in fragmented and diverse habitats. The species has attracted attention due to its secondary metabolite content, but little effort has as yet been dedicated to assessing the genetic and metabolite diversity present in these populations. Here, we describe the diversity of 50 H. italicum populations collected from a range of habitats in Sardinia.

Methods

H. italicum plants were AFLP fingerprinted and the composition of their leaf essential oil characterized by GC-MS. The relationships between the genetic structure of the populations, soil, habitat and climatic variables and the essential oil chemotypes present were evaluated using Bayesian clustering, contingency analyses and AMOVA.

Key results

The Sardinian germplasm could be partitioned into two AFLP-based clades. Populations collected from the southwestern region constituted a homogeneous group which remained virtually intact even at high levels of K. The second, much larger clade was more diverse. A positive correlation between genetic diversity and elevation suggested the action of natural purifying selection. Four main classes of compounds were identified among the essential oils, namely monoterpenes, oxygenated monoterpenes, sesquiterpenes and oxygenated sesquiterpenes. Oxygenated monoterpene levels were significantly correlated with the AFLP-based clade structure, suggesting a correspondence between gene pool and chemical diversity.

Conclusions

The results suggest an association between chemotype, genetic diversity and collection location which is relevant for the planning of future collections aimed at identifying valuable sources of essential oil.     

Chemical composition,antibacterial and antifungal activities of flowerhead and root essential oils of Santolina chamaecyparissus L., growing wild in Tunisia

The antimicrobial properties of essential oil from various Santolina species have not been investigated enough in the previous studies dealing with the biological activities of medicinal plants. In Tunisia, Santolina chamaecyparissus L. (Asteraceae) is the only Santolina species recorded and is used as vermifuge and emmenagogue. The chemical composition, antibacterial and antifungal properties of essential oils from the flowerheads and roots of spontaneous S. chamaecyparissus growing in Tunisia and the chemical composition which leads to the Tunisian chemotype are investigated here for the first time. Essential oils isolated by hydro distillation from flowerheads and roots of S. chamaecyparissus were analyzed by GC and GC/MS. Two methods served for antimicrobial assays of the essential oils: diffusion in a solid medium and micro-well dilution assay. Antifungal tests were carried out by the agar incorporation method. Sixty-seven constituents were identified from the essential oil of the flowerhead. The major constituents were: 1,8-cineole and β-eudesmol. Two non identified compounds were present at the highest concentration in root oil. Flowerhead oil was characterized by high contents in monoterpenes and sesquiterpenes oxygenated compounds. The flowerhead essential oil demonstrated potent of antibacterial properties against Pseudomonas aeruginosa ATCC and Enterococcus faecalis ATCC, with MIC of 0.625 μg/ml. These findings demonstrate that the flowerhead essential oils of S. chamaecyparissus have excellent antibacterial properties and for this reason they could contribute to decrease the problem of microbial resistance to antibiotics.     

Antimicrobial,antibiofilm and antitumor activities of essential oil of Agastache rugosa from Xinjiang,China

In the study, we evaluated chemical composition and antimicrobial, antibiofilm, and antitumor activities of essential oils from dried leaf essential oil of leaf and flower of Agastache rugosa for the first time. Essential oil of leaf and flower was evaluated with GC and GC–MS methods, and the essential oil of flower revealed the presence of 21 components, whose major compounds were pulegone (34.1%), estragole (29.5%), and p-Menthan-3-one (19.2%). 26 components from essential oil of leaf were identified, the major compounds were p-Menthan-3-one (48.8%) and estragole (20.8%). At the same time, essential oil of leaf, there is a very effective antimicrobial activity with MIC ranging from 9.4 to 42 μg ml⁻¹ and potential antibiofilm, antitumor activities for essential oils of flower and leaf essential oil of leaf. The study highlighted the diversity in two different parts of A. rugosa grown in Xinjiang region and other places, which have different active constituents. Our results showed that this native plant may be a good candidate for further biological and pharmacological investigations.     

Composition of essential oil of <Emphasis Type="Italic">Artemisia scoparia</Emphasis> Waldst. et Kit. from Buryatia and Mongolia

Essential oil from the epigeal portion of Artemisia scoparia Waldst. et Kit. collected in different regions of Buryatia and Mongolia has been isolated using steam distillation. The yield of essential oil from the stems and leaves of A. scoparia collected in different regions of Buryatia and in the Selenga aymag of Mongolia ranged from 0.06 to 0.40%, that is, the variation was rather high. The composition of the oil was analyzed using chromatography with mass spectrometric detection on a gas chromatography device Agilent Packard HP 6890 N with a quadrupole mass spectrometric detector HP MSD 5973. The total number of compounds detected exceeded 100. The major components of Artemisia scoparia oil were the following: p-cymene (0.6–15.2%), limonene (0.1–6.3%), α-pinene (0.2–10.1%), β-pinene (0.4–8.9%), trans-β-ocimene (0.3–5.4%), caryophyllene (4.6–13.8%), germacrene D (11.5–40.3%), spathulenol (4.0–11.7%), and caryophyllene oxide (4.3–15.6%). Several chemotypes of essential oil from A. scoparia were identified according to the nature of the major components: 1) oil that contained acetylene hydrocarbons (from plants collected in Gilan, Mazandaran, Kashan, and Tigran provinces of Iran, Tajikistan, and the European part of the CIS); 2) oil that contained monoterpenes and aromatic compounds (from plants collected in the Khorasan province of Iran, India, and South Korea); and 3) oil that contained monoterpenes or aromatic and sesquiterpene compounds (from plants collected in Kazakhstan and Mongolia). The major components of A. scoparia essential oil obtained from Buryatian plants belonged to the classes of mono- and sesquiterpene compounds, and thus the oil can be assigned to the third chemotype characteristic of A. scoparia from geographically close regions.     

Chemical composition and antifungal effect of anise (Pimpinella anisum L.) fruit oil at ripening stage

The composition of the essential oil ofPimpinella anisum L fruit is determined by GC and GC-MS. The volatile oil content obtained by hydrodistillation was 1.91%. Ten compounds representing 98.3% of the oil was identified. The main constituents of he oil obtained from dried fruits were trans-a nethole (93.9%) and estragole (2.4%). The olfactorially valuable constituents that were found with concentration higher than 0.06% were (E)-methyeugenol, α-cuparene, α-himachalene, β-bisabolene, p-anisaldehyde and cis-anethole. Also, the different concentrations of anise oil exerted varying levels of inhibitory effects on the mycelial growth off/ternaria alternata, Aspergillus niger andAspergillus parasiticus used in experimental. The results showed that the most effected fungus from anise oil wasA. parasiticus, which is followed byA. niger andA. alternata. Individual of this plant oil may provide a useful to achive adequate shelf-life of foods.     

The composition of the essential oil from raw material and cones of Juniperus sibirica from Evenk region

The composition of the essential oil from raw material and cones of Juniperus sibirica from Evenk region has been investigated using chromato-mass-spectrometry. The essential oil was shown to comprise no less than 120 components, more than 40 of which are major and were identified in the present study. It was established that quantitative distillation of the essential oil takes 22 h, and during its extraction the composition of the oil changes.     

New C9-polyacetylenes from the essential oil of the highly endangered species Baccharis palustris Heering (Asteraceae)

The essential oil composition of the aerial parts from Baccharis palustris Heering (Asteraceae), a highly endangered species, was analyzed by GC/qMS, GC/HRMS-TOF, FT-IR, UV–vis and NMR spectroscopy using 1D and 2D techniques. To our knowledge, this is the first report on the essential oil composition of B. palustris, as well as the first phytochemical study on this plant species. The volatile extracts were obtained from different phenologicals stages of plant, at flowering stage (FS) and vegetative stage (VS), where 51 components were identified accounting for 96.3 % and 99.0 % of the oil, respectively. The oil was rich in polyacetylene compounds (> 75 %), being the main components identified the new natural C₉-polyacetylenes 1-nonene-3,5-diyne (1, here named as baccharisdiyne) (52.7–65.0 %), 1,7(Z)-nonadiene-3,5-diyne [2, 7(Z)-dehydro-baccharisdiyne] (14.4–17.8 %), and 1,7(E)-nonadiene-3,5-diyne [3, 7(E)-dehydro-baccharisdiyne] (1.5–2.4 %). In addition, the known polyacetylenic compounds (Z)-lachnophyllum acid methyl ester (4) (4.3–5.3 %) and (E)-lachnophyllum acid methyl ester (5) (0.2 %) were also identified. Moreover, GC/qMS analysis allowed the identification of other 46 components in the essential oil samples, mainly mono- and sesquiterpenoids. In B. palustris, C₉-polyacetylenes probably derive biogenetically from a C₁₀ precursor: baccharisdiyne (1) would be derived from either or both lachnophyllum methyl ester geometric isomers (4 or 5), by enzymatic hydrolysis followed by decarboxylation. Dehydro-baccharisdiynes (2 and 3) could be produced by a similar pathway starting from the corresponding matricaria acid methyl ester isomers, one of which was tentatively identified at trace-level in B. palustris essential oil.