Antifungal activities of essential oils applied by dip-treatment on areca palm (Areca catechu) leaf sheath and persistence of their potency upon storage

The antifungal activities of cinnamon oil, clove oil, anise oil, and peppermint oil, and their main components (cinnamaldehyde, eugenol, trans-anethole, and menthol, respectively) against molds identified from areca palm leaf sheath (Mucor dimorphosporus, Penicillium sp., Aspergillus niger, and Rhizopus sp.) were investigated. An agar dilution method was employed to determine the minimum inhibitory concentration (MIC) of essential oils and their main components. Zone inhibition tests and the inhibitory effect of the leaf sheath dip-treated with essential oils against those molds were examined. Major components of essential oils on the leaf sheath during storage were quantified by gas chromatography analysis. The MIC values of essential oils on agar and on the leaf sheath were identical. With an MIC of 50 ??g ml⁻¹, cinnamon oil had the strongest inhibitory effect. At their MICs the oils were capable of providing protection against mold growth on the leaf sheath for at least 12 weeks during storage at 25 °C and 100% RH. Scanning electron microscope examination showed that essential oils prevented spore germination. Except for menthol in peppermint oil, the main components of the essential oils, which were fairly stable over the storage period, largely contributed to the antifungal activity.     

Effects of Thymus revolutus Célak essential oil and its two major components on Hep G2 cells membrane

In this study pro/anti-oxidant activities of Thymus revolutus Célak (T. revolutus C.) essential oil and its two main components on Hep G2 cells were determined. Twelve components were identified in T. revolutus C. essential oil by GC and GC-MS and the main components of the oil were cymene (32.57%) and γ-terpinene (17.18%). The essential oil showed more cytotoxicity than its two main components on Hep G2 after 24, 48 and 72 hours incubations. Membrane damage effects of the essential oil and its two main components on Hep G2 cells were increased by incubation with IC₁₀, IC₅₀ and IC₇₀ concentrations. Lower essential oil (<IC₅₀) concentrations had cytoprotective and membrane protective effects against H₂O₂. The free radical scavenging activity of the essential oil of T. revolutus C. (EC₅₀ = 250±0.2 μg/mL) was superior to its two main components (neither not active). Oxidation of linoleic acid was effectively inhibited by T. revolutus C. (72.8%), while inhibition values of linoleic acid oxidation were calculated as 23.4.% and 26.7% for cymene and Γ-terpinene, respectively. These findings suggest that essential oils and its two main components had both pro-oxidant and protective (antioxidant) effects and they exhibited those effects depending on concentration.     

Essential oil composition of four Lomatium Raf. species and their chemotaxonomy

The composition of the essential oils of Lomatium dasycarpum ssp. dasycarpum, Lomatium lucidum, Lomatium macrocarpum var. macrocarpum and Lomatium utriculatum is described. Identification of components was determined from their GC, GC/MS data and many were confirmed by coinjections with authentic samples. Several components were isolated by liquid and gas chromatographic techniques and their structures confirmed from their ¹H and ¹³C NMR spectral data. 2-Methyl and 3-methylbutanoates were the major components of L. dasycarpum fruits as well as stems and leaves oils. β-Phellandrene/limonene, decanal, dodecanal, bornyl acetate, germacrene D, α-humulene and bicyclogermacrene were the major components of the corresponding L. lucidum oils. α-Pinene and β-pinene were the major components of the fruit oil of L. macrocarpum. Its stem and leaf oil was rich in peucenin 7-methyl ether, β-caryophyllene, (Z)-3-hexenol, palmitic acid, linoleic acid and (E)-2-hexenal. Sabinene, (Z)-ligustilide, terpinen-4-ol, β-phellandrene/limonene, β-caryophyllene, myrcene, α-pinene and β-pinene were the major compounds in L. utriculatum fruit oil, while its stem and leaf oil was rich in (Z)-ligustilide, palmitic acid, terpinen-4-ol, linoleic acid and germacrene D. (Z)-Falcarinol was a major component of all the four root oils.     

Chemical composition, antioxidant activity and inhibitory effects of essential oil of Eucalyptus teretecornis grown in north-western Himalaya against Alternaria alternata

The essential oil obtained from fresh leaves of Eucalyptus teretecornis (family Myrtaceae) was analysed by gas chromatography/mass spectrometry (GC/MS). Twenty eight compounds were identified and ??-pinene (22.55%), ??-pinene (22.50%), 1,8-cineole (19.84%), limonene (5.62%), ??-fenchol (3.10%), ??-phellandrene (2.90%), ??-eudesmol (2.66%) and 4-(2-methylcyclohex-1-enyl)-but-2-enal (2.34%) were the main components. The antifungal activity of the essential oil was assayed against Alternaria alternata using bioautography. Two main bioactive components namely a₁ (R _f ?=?0.27) and a₂ (R _f ?=?0.33) were observed that produced inhibition zone of 4?mm and 8?mm in diameter respectively. The minimum inhibitory amount (MIA) of a₁ and a₂ against A. alternata was determined as 28???g and 10???g, respectively using bioautography assay. Components corresponding to a₁ and a₂ were determined as ??-fenchol (oxygenated monoterpene) and ??-eudesmol (oxygenated sesquiterpene) respectively using GC/MS analysis. The antioxidant activity of the essential oil and its bioactive fraction was evaluated by DPPH radical scavenging assay, ??-carotene/linoleic acid bleaching assay, reducing power assay and metal chelating assay. In addition fraction of the essential oil that showed antioxidant activity was analyzed using GC/MS and ??-fenchol, 4-terpineol and carvacrol were the main components.     

Durability of rubberwood (Hevea brasiliensis) treated with peppermint oil,eucalyptus oil,and their main components

Anti-fungal activities of two essential oils (peppermint oil and eucalyptus oil) and their main components (menthol and eucalyptol, respectively) against molds (Aspergillus niger, Penicillium chrysogenum, and Penicillium sp.) and a white-rot decay fungus (Trametes versicolor) identified from rubberwood surfaces were investigated. The broth dilution method and the agar diffusion technique were employed to determine the minimal inhibitory concentration (MIC) and the minimal fungicidal concentration (MFC) using the concentration of substances between 100 and 800 μl ml^?1. Inhibitory effects of essential oils and their main components at the MICs against mold growth, fungal decay, and termite attack on rubberwood were further examined by means of the dip treatment method. It was found that MFC values against molds for all treatments examined were about 50–100 μl ml^?1 higher than MIC values. Peppermint oil and menthol exhibited high fungistatic and fungicidal activities, with MICs of 300 μl ml^?1 and 350 μl ml^?1, respectively, against the test molds and the decay fungus. Eucalyptus oil and eucalyptol were also effective against these microbes but at higher concentrations of 600 μl ml^?1 and 500 μl ml^?1, respectively. Only peppermint oil at the MIC was capable of providing a complete protection from mold growth on rubberwood for up to 12 weeks at storage conditions of 25 °C and 100% RH. Both peppermint oil and eucalyptus oil at the MICs showed moderate resistance to fungal decay and high resistance to termite attack.     

Volatile constituents of male and female boll weevils and their frass

The volatile constituents of male and female boll weevils, Anthonomus grandis, and their frass were analysed by GLC-MS. The 4 previously identified components of the male pheromone were present only in the male volatile oil (3·9%) and in the male frass volatile oil (38·9%). The compounds found in one or both sexes and their frass include 26 carbonyls, 23 hydrocarbons, 12 alcohols, 6 phenols, 4 esters, 3 furans, 1 ether, and 1 lactone. Also found were 2 compounds containing nitrogen, 1 halogen, and 1 sulphur. There were 33 terpenes and 24 aromatic compounds. 3,7-Dimethyl-1-octanol comprised 15·6 per cent of the male frass oil. Carvone was found only in females (5·4%) and in female frass (6·8%). A series of monoterpene aldehydes (M⁺ 152) were found only in the female frass oil. A pheromone rôle for these components was suggested.     

Variability in Pseudomonas aeruginosa Lipopolysaccharide Expression during Crude Oil Degradation

Bacterial utilization of crude oil components, such as the n-alkanes, requires complex cell surface adaptation to allow adherence to oil. To better understand microbial cell surface adaptation to growth on crude oil, the cell surface characteristics of two Pseudomonas aeruginosa strains, U1 and U3, both isolated from the same crude oil-degrading microbial community enriched on Bonny Light crude oil (BLC), were compared. Analysis of growth rates demonstrated an increased lag time for U1 cells compared to U3 cells. Amendment with EDTA inhibited U1 and U3 growth and degradation of the n-alkane component of BLC, suggesting a link between cell surface structure and crude oil degradation. U1 cells demonstrated a smooth-to-rough colony morphology transition when grown on BLC, while U3 cells exhibited rough colony morphology at the outset. Combining high-resolution atomic force microscopy of the cell surface and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of extracted lipopolysaccharides (LPS), we demonstrate that isolates grown on BLC have reduced O-antigen expression compared with that of glucose-grown cells. The loss of O-antigen resulted in shorter LPS molecules, increased cell surface hydrophobicity, and increased n-alkane degradation.     

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.     

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.     

Analysis of the volatile components of Lavandula canariensis (L.) Mill., a Canary Islands endemic species,growing in Australia

The essential oil of a Canary Islands endemic species, Lavandula canariensis (L.) Mill., gathered from Australia, was extracted by hydrodistillation and solid phase micro-extraction (SPME). The oils have been studied by GC and GC–MS. A total of 38 compounds have been identified in the leaf oil extracted by hydrodistillation, the principal components being carvacrol (23.6%), β-bisabolene (20.8%), (E,E)-α-farnesene (11.3%), β-caryophyllene (7.6%) and carvacrol methyl ether (7.3%), while the oil extracted by SPME showed carvacrol (42.6%) as the principal component with moderate amounts of (E,E)-α-farnesene (9.1%), β-bisabolene (7.5%), cis-hex-3-en-1-ol (5.6%) and carvacrol methyl ether (4.6%). SPME extracts indicated that carvacrol, cis-hex-3-en-1-ol and linalool were in greater concentration in the head space vapours than in the oil. This is the first report describing the essential oil composition of this species.     

Constituents of the essential oil of Artemisia rehan

The composition of the essential oil of A. rehan has been studied. A total of 22 components were identified, the major components being davanone and camphor, and the occurrence of eudalene is noted for the first time. The characteristic blue colour of the oil is due to chamazulene.     

Scolicidal Effects of Black Cumin Seed (Nigella sativa) Essential Oil on Hydatid Cysts

Surgery remains the preferred treatment for hydatid cyst (cystic echinococcosis, CE). Various scolicidal agents have been used for inactivation of protoscolices during surgery, but most of them are associated with adverse side effects. The present study aimed to evaluate the in vitro scolicidal effect of Nigella sativa (Ranunculaceae) essential oil and also its active principle, thymoquinone, against protoscolices of hydatid cysts. Protoscolices were aseptically aspirated from sheep livers having hydatid cysts. Various concentrations of the essential oil (0.01-10 mg/ml) and thymoquinone (0.125-1.0 mg/ml) were used for 5 to 60 min. Viability of protoscolices was confirmed by 0.1% eosin staining. Furthermore, the components of the N. sativa essential oil were identified by gas chromatography/mass spectroscopy (GC/MS). Our study revealed that the essential oil of N. sativa at the concentration of 10 mg/ml and its main component, thymoquinone, at the concentration of 1 mg/ml had potent scolicidal activities against protoscolices of Echinococcus granulosus after 10 min exposure. Moreover, thymoquinone (42.4%), p-cymene (14.1%), carvacrol (10.3%), and longifolene (6.1%) were found to be the major components of N. sativa essential oil by GC/MS analysis. The results of this study indicated the potential of N. sativa as a natural source for production of a new scolicidal agent for use in hydatid cyst surgery. However, further studies will be needed to confirm these results by checking the essential oil and its active component in in vivo models.     

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.     

Synthesis of fatty acid methyl ester from used vegetable cooking oil by solid reusable Mg 1-x Zn 1+x O2 catalyst

Fatty acid methyl ester was produced from used vegetable cooking oil using Mg_1−x Zn_1+xO₂ solid catalyst and the performance monitored in terms of ester content obtained. Used vegetable cooking oil was employed to reduce operation cost of biodiesel. The significant operating parameters which affect the overall yield of the process were studied. The highest ester content, 80%, was achieved with the catalyst during 4 h 15 min reaction at 188 °C with methanol to oil ratio of 9:1 and catalyst loading of 2.55 wt% oil. Also, transesterification of virgin oil gave higher yield with the heterogeneous catalyst and showed high selectivity towards ester production. The used vegetable cooking oil did not require any rigorous pretreatment. Catalyst stability was examined and there was no leaching of the active components, and its performance was as good at the fourth as at the first cycle.     

Evaluation of the Activity of the Essential Oil from an Ornamental Flower against Aedes aegypti: Electrophysiology,Molecular Dynamics and Behavioral Assays

Dengue fever has spread worldwide and affects millions of people every year in tropical and subtropical regions of Africa, Asia, Europe and America. Since there is no effective vaccine against the dengue virus, prevention of disease transmission depends entirely on regulating the vector (Aedes aegypti) or interrupting human-vector contact. The aim of this study was to assess the oviposition deterrent activity of essential oils of three cultivars of torch ginger (Etlingera elatior, Zingiberaceae) against the dengue mosquito. Analysis of the oils by gas chromatography (GC)—mass spectrometry revealed the presence of 43 constituents, of which α-pinene, dodecanal and n-dodecanol were the major components in all cultivars. Solutions containing 100 ppm of the oils exhibited oviposition deterrent activities against gravid Ae. aegypti females. GC analysis with electroantennographic detection indicated that the oil constituents n-decanol, 2-undecanone, undecanal, dodecanal, trans-caryophyllene, (E)-β-farnesene, α-humulene, n-dodecanol, isodaucene and dodecanoic acid were able to trigger antennal depolarization in Ae. aegypti females. Bioassays confirmed that solutions containing 50 ppm of n-dodecanol or dodecanal exhibited oviposition deterrent activities, while a solution containing the alcohol and aldehyde in admixture at concentrations representative of the oil presented an activity similar to that of the 100 ppm oil solution. Docking and molecular dynamics simulations verified that the interaction energies of the long-chain oil components and Ae. aegypti odorant binding protein 1 were quite favorable, indicating that the protein is a possible oviposition deterrent receptor in the antenna of Ae. aegypti.     

Constituents of the essential oil of Lavandula latifolia

Thirty components were identified in Lavandula latifolia essential oil (spike oil). One of the compounds, espliegol (δ-terpineol), is a new natural product.     

Leaf essential oils and their application in systematics of Juniperus excelsa complex in Iran

The composition of the leaf essential oils of ten populations of Juniperus excelsa complex in Iran are reported and compared. Hydrodistillation yielded in 0.08%–3.78% dry weight (v/w) clear oils among populations studied. The oils are mostly dominated by α- Pinene, Limonene and β-Myrcene. The simplest oil was found in Qushchi (J. polycarpos var. polycarpos) with 25 components and the most complex oil was found in Lushan1 (J. polycarpos var. polycarpos) with 92 components. Quantitative data is presented for 164 components were found. The southern populations, Fasa and Khabr, show differences in composition of essential oils compared with other populations so that Borneol and isopinocamphone are diagnostic for them. These populations have been identified as Juniperus seravschanica in southeast of Iran and hybrid samples between J. polycarpos and J. seravschanica in southwest of Iran whereas other populations, as is confirmed in this study, are J. polycarpos. It is confirmed by essential oils data that there is no J. excelsa in Iran.     

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.     

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.     

Volatile constituents of Cupressus dupreziana and the sesquiterpenes of Cupressus sempervirens

Analysis of wood essential oil of Cupressus dupreziana revealed 26 components: 13 monoterpenes and 13 sesquiterpenes. The main components were carv