Chemical composition and antifungal activity of Arnica longifolia, Aster hesperius, and Chrysothamnus nauseosus essential oils

Essential oils from three different Asteraceae obtained by hydrodistillation of aerial parts were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS). Main compounds obtained from each taxon were found as follows: Arnica longifolia carvacrol 37.3%, alpha-bisabolol 8.2%; Aster hesperius hexadecanoic acid 29.6%, carvacrol 15.2%; and Chrysothamnus nauseosus var. nauseosus beta-phellandrene 22.8% and beta-pinene 19.8%. Essential oils were also evaluated for their antimalarial and antimicrobial activity against human pathogens, and antifungal activities against plant pathogens. No antimalarial and antimicrobial activities against human pathogens were observed. Direct bioautography demonstrated antifungal activity of the essential oils obtained from three Asteraceae taxa and two pure compounds, carvacrol and beta-bisabolol, to the plant pathogens Colletotrichum acutatum, C. fragariae and C. gloeosporioides. Subsequent evaluation of antifungal compounds using a 96-well micro-dilution broth assay indicated that alpha-bisabolol showed weak growth inhibition of the plant pathogen Botrytis cinerea after 72 h.     

Chemical composition and antifungal activity of essential oils from different tissues of Japanese Cedar (Cryptomeria japonica)

In this study antifungal activities of essential oils from different tissues of Japanese cedar (Cryptomeria japonica D. Don) against four wood decay fungi and six tree pathogenic fungi were investigated. In addition, the yields of essential oils obtained by water distillation were compared and their constituents determined by GC-MS analyses. The yield of essential oils from four tissues of Japanese cedar is in the decreasing order of leaf (27.38 mL/kg) > bark (6.31 mL/kg) > heartwood (3.80 mL/kg) > sapwood (1.27 mL/kg). Results obtained from the antifungal tests demonstrate that the essential oil of Japanese cedar heartwood used against Laetiporus sulphureus and Trametes versicolor and sapwood essential oil used against L. sulphureus had strong antifungal activities at 500 mug/mL, with IC(50) values of 39, 91, and 94 microg/mL, respectively. Besides, the essential oils of Japanese cedar heartwood used against Rhizoctonia solani, Collectotrichum gloeosporioides, Fusarium solani, and Ganoderma australe had strong antifungal activities at 500 microg/mL, with IC(50) values of 65, 80, 80, and 110 microg/mL, respectively. GC-MS analyses showed that the sesquiterpene hydrocarbon compounds dominate in the essential oil from Japanese cedar heartwood, amounting to a total percentage of 82.56%, with the major compounds of delta-cadinene (18.60%), isoledene (12.41%), and gamma-muurolene (11.82%). It is proposed that the excellent antifungal activities of Japanese cedar heartwood essential oils might correlate with the presence of these compounds.     

Chemical composition of volatiles in Sardinian myrtle (Myrtus communis L.) alcoholic extracts and essential oils

The chemical composition of the volatile fraction of myrtle (Myrtus communis L.) alcoholic extracts and essential oils from leaves and berries collected in different places in Sardinia (Italy) was studied. A simple and rapid liquid-liquid extraction method was used to isolate volatile compounds from myrtle alcoholic extracts followed by GC and GC-MS analysis allowing the detection of 24 compounds. The volatile fraction was characterized by the terpenes fraction corresponding to that of the essential oils and by a fatty acid ethyl esters fraction. The variation during extraction of the volatile fraction in alcoholic extracts of berries and leaves was evaluated. Essential oils were obtained by hydrodistillation, and the yields were on average 0.52 +/- 0.03% (v/w dried weight) and 0.02 +/- 0.00% for leaves and berries, respectively. The essential oils were analyzed by GC and GC-MS, and a total of 27 components were detected, accounting for 90.6-98.7% of the total essential oil composition. Strong chemical variability depending on the origin of the samples was observed. The major compounds in the essential oils were alpha-pinene (30.0 and 28.5%), 1,8-cineole (28.8 and 15.3%), and limonene (17.5 and 24.1%) in leaves and berries, respectively, and were characterized by the lack of myrtenyl acetate.     

Organ- and season-dependent variation in the essential oil composition of Salvia officinalis L. cultivated at two different sites.

More than 50 compounds were identified in essential oils from stems and leaves of Salvia officinalis L. plants harvested in July, in Arouca, in northern Portugal. About 40 of those compounds were also present in flower essential oils, collected from the same plants. alpha-Thujone was the major compound, representing about 55, 30, and 18% of the essential oils from stems, leaves, and flowers, respectively. Significant percentage variations in the main compound classes of the essential oils from shoots sampled over the year were recorded at two different sites in northern Portugal. From December to April, oxygenated monoterpenes (MO) decreased from approximately 67-72% to values of 42-43% of the essential oils. During the same time interval, the percentage of monoterpene hydrocarbons (MH) rose from 8-11% to 17-22%. At both sites, sesquiterpene hydrocarbons (SH) rose from approximately 7% in February to 19-22% in April, decreasing thereafter to approximately 9% in July. Oxygenated sesquiterpenes (SO) increased from a minimum of approximately 5% in July to a maximum of 8-11% in February, decreasing thereafter. The compounds that mostly accounted for the essential oil composition variation were alpha-pinene, beta-pinene, and camphene, as MH; alpha-thujone and camphor, as MO; alpha-humulene and beta-caryophyllene, as SH; and viridiflorol, as SO.     

Changes in essential oil during enzyme-assisted ensiling of lemongrass (Cymbopogon citratus Stapf.) and lemon eucalyptus (Eucalyptus citriodora Hook)

Changes in essential oil during ensiling of lemongrass and lemon eucalyptus were studied. Wilted lemongrass and eucalyptus leaves were ensiled in 0.25-L anaerobic jars. Samples consisted of a control (no additives) and a treated sample (0.5% glucose and lactic acid bacteria and 1% cellulase plus 1% hemicellulase plus pectinase). Three jars per treatment were sampled on days 2, 6, 10, and 36 for analysis of essential oil. Essential oil was obtained by extraction and by hydrodistillation. Extraction efficacy of essential oil from the lemongrass was improved by the enzyme treatment, but it was much lower than the amount obtained by distillation. The major components of the essential oil were neral and geranial. In the eucalyptus, total essential oils obtained by distillation decreased during ensiling, and the amount was similar to the amount obtained by extraction. Citronellal, which was the major component of the essential oil in the fresh eucalyptus leaves, decreased, whereas isopulegol and 3,8-terpinolhydrate increased during ensiling.     

Chemical composition, seasonal variability, and antifungal activity of Lavandula stoechas L. ssp. stoechas essential oils from stem/leaves and flowers

Essential oils from the stems/leaves (L) and flowers (F) of Lavandula stoechas L. ssp. stoechas growing wild in southern Sardinia (Italy) were extracted by hydrodistillation and analyzed by gas chromatography coupled with flame ionization detector and ion trap mass spectrometry. The major compound was fenchone, accounting for, on average, 52.60% in L and 66.20% in F, followed by camphor (13.13% versus 27.08%, in L and F, respectively). F essential oil yields (volume per dry weight) decreased from the beginning to the end of the flowering stage, whereas L yields remained constant during the year. The nine main compounds derived from two different subpathways, A and B. The compounds that belong to the same subpathway showed a similar behavior during the year. The essential oils were tested for their antifungal activity using the paper disk diffusion method. The essential oils tested were effective on the inactivation of Rhizoctonia solani and Fusarium oxysporum and less effective against Aspergillus flavus. Among the single compounds tested, fenchone, limonene, and myrtenal appeared to be the more effective on the inhibition of R. solani growth.     

Effect of solution conductivity on the volatile constituents of Origanum dictamnus L. in nutrient film culture

The chemical composition of the essential oils obtained from leaves and bracts of hydroponically cultivated Origanum dictamnus L. (Cretan dittany), growing under various electrical conductivity (EC) levels (2.0, 4.0, and 6.0 mS/cm), was studied, using the nutrient film technique (NFT). The analysis of the essential oil content was achieved by GC-MS technique, and totals of 41 and 38 different compounds were identified in both cases of large-leaved and narrow-leaved samples of leaves and bracts, respectively. Differences in the composition content and of the percentage of each of the constituents in the two studied samples (i.e., large-leaved and narrow-leaved) and within the essential oils of leaves and bracts in both samples were observed. Carvacrol and p-cymene were identified as the main constituents in all essential oils, whereas thymoquinone was found in higher percentage in the essential oils of large-leaved than in narrow-leaved plants. The results obtained from GC-MS analysis were submitted to chemometric analysis, and a phenotypic similarity of the essential oils of narrow-leaved O. dictamnus was observed, whereas the essential oils of large-leaved O. dictamnus showed two separate subgroups.     

Main agronomic-productive characteristics of two ecotypes of Rosmarinus officinalis L. and chemical composition of their essential oils

The productive potential of two different ecotypes of Rosmarinus officinalis (Cevoli and Lunigiana) cultivated in the littoral area near Pisa (northern Tuscany, Italy) and the differences in the yield and composition of the essential oils of leaves, flowers, and stems obtained from different positions of the plants were used to characterize the two ecotypes. The Cevoli ecotype plant produced the highest yield of dry matter (221 g plant-1) in comparison to the Lunigiana ecotype (72 g plant-1). There were significant differences in dry matter production of different organs of both ecotypes. The essential oil contents of Cevoli and Lunigiana ecotypes were similar. In contrast, the oil contents of the different plant parts showed marked differences. The apical part of the plant and the leaves gave the highest essential oil yields. The major difference between the oils of the two ecotypes consisted in the 1,8-cineole contents (6.6 and 37.9% in Cevoli and Lunigiana, respectively). The Cevoli ecotype was determined to be the most suitable for essential oil extraction because it was characterized by a preponderance of flowers and leaves in the apical portion. The Cevoli ecotype could be classifited as an alpha-pinene chemotype, whereas Lunigiana is a 1,8-cineole chemotype.     

Composition and seasonal variation of the essential oil from leaves and peel of a Cretan lemon variety.

The essential oil of leaves and peel from the Cretan variety Zambetakis (Citrus limon) was obtained by steam distillation with a Clevenger apparatus. The essential oil was subjected to GC-MS analysis, and 35 substances were identified. The main component in both essential oils was limonene. beta-Pinene, myrcene, neral, geranial, neryl acetate, geranyl acetate, and beta-caryophyllene have been identified in the leaf oil. The peel oil contained gamma-terpinene, beta-pinene, myrcene, neral, and geranial. The quantification of volatile substances was based on the internal standard method, using octyl acetate as internal standard, and expressed in milligrams per kilogram of the essential oil. The high contents of neral and geranial were indicative of the high quality of both essential oils. The aroma profile and quantitative variations among the essential oil components were measured at six different time intervals over a period of greater than one year. Differences between the components of lemon leaves and peel were observed.     

Essential oil composition of diploid and tetraploid clones of ginger (Zingiber officinale Roscoe) grown in Australia

Ginger oil, obtained by steam distillation of the rhizome of Zingiber officinale Roscoe, is used in the beverage and fragrance industries. Ginger oil displays considerable compositional diversity, but is typically characterized by a high content of sesquiterpene hydrocarbons, including zingiberene, ar-curcumene, beta-bisabolene, and beta-sesquiphellandrene. Australian ginger oil has a reputation for possessing a particular "lemony" aroma, due to its high content of the isomers neral and geranial, often collectively referred to as citral. Fresh rhizomes of 17 clones of Australian ginger, including commercial cultivars and experimental tetraploid clones, were steam distilled 7 weeks post-harvest, and the resulting oils were analyzed by GC-MS. The essential oils of 16 of the 17 clones, including the tetraploid clones and their parent cultivar, were found to be of substantially similar composition. These oils were characterized by very high citral levels (51-71%) and relatively low levels of the sesquiterpene hydrocarbons typical of ginger oil. The citral levels of most of these oils exceeded those previously reported for ginger oils. The neral-to-geranial ratio was shown to be remarkably constant (0.61 +/- 0.01) across all 17 clones. One clone, the cultivar "Jamaican", yielded oil with a substantially different composition, lower citral content and higher levels of sesquiterpene hydrocarbons. Because this cultivar also contains significantly higher concentrations of pungent gingerols, it possesses unique aroma and flavor characteristics, which should be of commercial interest.     

Production of yarrow (Achillea millefolium L.) in Norway: essential oil content and quality

In 1996, the production of Achillea millefolium L. at different locations in Norway was investigated with regard to the developmental stage. The oil content differed greatly between the vegetative stage (0.13%) and the stage of full bloom (0.34%). Changes in the composition of yarrow essential oil were found to be related to maturation of the plant, with increasing amounts of monoterpenes in relation to the sesquiterpene. However, a clear trend could be detected only for the monoterpenic compounds with increasing levels of alpha- and beta-pinene and alpha-thujone and decreasing levels of sabinene, borneol, and bornyl acetate. Previously reported as major compounds, chamazulene and germacrene D could be found only in insignificant amounts. A solid-phase microextraction (SPME) procedure was applied for screening of the terpenic composition. Sesquiterpenic compounds such as beta-bisabolene, alpha-bisabolol, and delta-cadinene were detected in substantial amounts by SPME in contrast to the steam-distilled samples.     

Antibacterial activity of Coriandrum sativum L. and Foeniculum vulgare Miller Var. vulgare (Miller) essential oils

Essential oils were extracted from the fruits of Coriandrum sativum L. and Foeniculum vulgare Miller var. vulgare (Miller) and assayed in vitro for antibacterial activity to Escherichia coli and Bacillus megaterium, bacteria routinely used for comparison in the antimicrobial assays, and 27 phytopathogenic bacterial species and two mycopathogenic ones responsible for cultivated mushroom diseases. A significant antibacterial activity, as determined with the agar diffusion method, was shown by C. sativum essential oil whereas a much reduced effect was observed for F. vulgare var. vulgare oil. C. sativum and F. vulgare var. vulgare essential oils may be useful natural bactericides for the control of bacterial diseases of plants and for seed treatment, in particular, in organic agriculture. The significant antibacterial activity of essential oils to the bacterial pathogens of mushrooms appears promising.     

Dynamics of yield components and essential oil production in a commercial hybrid sage (Salvia officinalis x Salvia fruticosa cv. Newe Ya'ar no. 4).

The fresh yields, the essential oil content, and the quality of a sage hybrid (Salvia officinalis x Salvia fruticosa, cv. Newe Ya'ar No. 4, Lamiaceae) as affected by development and harvest time were determined. Marked increases in plant height and in the number of nodes developed per plant together with a modest increase in leaf size were accompanied by dramatic increases (more than 20-fold) in the fresh yields throughout a 50-day growth period. No major changes in the essential oil content per fresh weight and its composition were detected throughout the growth period. In contrast, the compositions of the essential oils obtained from stems, as compared to leaves and leaf-primordia, had marked differences. Developmentally controlled changes in the extractives from individual leaf pairs from the same plant were also noted. In upper young leaves, the oxygenated diterpene manool and the sesquiterpene hydrocarbons alpha-humulene and beta-caryophyllene constituted up to 20%, 8%, and 4% of the total extractives, respectively. In older leaves, the abundance of these components steadily dropped to roughly half their levels in young leaves. Conversely, the proportions of the monoterpenes, particularly the ketones camphor and alpha-thujone, steadily increased with leaf position. Minor changes in the levels of other extractives were also recorded. These studies imply independent regulatory patterns for di-, sesqui-, and monoterpenes in this sage hybrid, and suggest possible agrotechnical means to obtain preferred chemical compositions of its essential oil.     

Chemical composition and antifungal activity of Salvia macrochlamys and Salvia recognita essential oils

Essential oils of Salvia macrochlamys and Salvia recognita were obtained by hydrodistillation of dried aerial parts and characterized by gas chromatography and gas chromatography-mass spectrometry. One hundred and twenty identified constituents representing 97.7% in S. macrochlamys and 96.4% in S. recognita were characterized, and 1,8-cineole, borneol, and camphor were identified as major components of the essential oils. The oils were evaluated for their antimalarial, antimicrobial, and antifungal activities. Antifungal activity of the essential oils from both Salvia species was nonselective at inhibiting growth and development of reproductive stroma of the plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides. S. macrochlamys oil had good antimycobacterial activity against Mycobacterium intracellulare; however, the oils showed no antimicrobial activity against human pathogenic bacteria or fungi up to a concentration of 200 microg/mL. S. recognita oil exhibited a weak antimalarial activity against Plasmodium falciparum.     

Chemical composition of the essential oils of Juniperus from ripe and unripe berries and leaves and their antimicrobial activity

The composition of the essential oil from ripe and unripe berries and leaves of Juniperus oxycedrus L. ssp. oxycedrus, Juniperus phoenicea ssp. turbinata and Juniperus communis ssp. communis was analyzed by GC-MS, and microbiological assays were carried out. Samples were collected in different localities (Sardinia, Italy) and hydro distilled. The yields ranged between 2.54% +/- 0.21 (v\w dried weight) and 0.04% +/- 0.00. A total of 36 components were identified. The major compounds in the essential oils were alpha-pinene, beta-pinene, delta-3-carene, sabinene, myrcene, beta-phellandrene, limonene, and D-germacrene. Both qualitative and quantitative differences between species and between different parts of the plant were observed. The essential oils and their major compounds were tested against Candida albicans, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and the minimum inhibitory concentration and minimum bactericidal concentration were determined. The results obtained led to a nonsignificant inhibitory effect, although all the essential oils from Juniperus phoenicea ssp. turbinata and the essential oil from leaves of Juniperus oxycedrus ssp. oxycedrus exhibited rather good or weak activity against Candida albicans and Staphylococcus aureus.     

Antioxidative properties of Thymus vulgaris leaves: comparison of different extracts and essential oil chemotypes

Thyme (Thymus vulgaris L., Lamiaceae) is a subshrub from the Lamiaceae family with plants that are rich in essential oils and antioxidative phenolic substances. Twelve accessions originating from southern France and the variety 'Deutscher Winter' were grown in an experimental field in eastern Austria. Leaf samples from these plants as well as from a commercial thyme rich in thymol were analyzed for their essential oil and the antioxidative potential in various extracts. The assays for antioxidative activity were the total phenolics according to the Folin-Ciocalteu method, DPPH decoloration, and Fe(3+) reduction (FRAP). Both extraction techniques used, in the water bath at 40 degrees C and in the ultrasonic bath at room temperature, proved to be efficient. The best results were obtained with 60% ethanol as extractant. In the comparison of the different accessions the less active and the most active of these extracts differed by factors of 2.1 and 2.6 in the total phenolics and FRAP assay, respectively, and by factors 1.5-2.0 in the DPPH assay. Rosmarinic acid accounted for 22-55% of the antioxidant activity in the ethanolic extracts. Essential oils with high proportions of the phenolic components thymol and/or carvacrol showed the highest antioxidant activity. Ethanolic extracts from the residues after distillation were considerably lower in antioxidant activity than the respective extracts from the dried leaves. Extracts with CH2Cl2 in the ultrasonic bath contained volatiles in proportions close to the essential oil but displayed very low antioxidant activity.     

Characterization of the volatile composition of essential oils of some lamiaceae spices and the antimicrobial and antioxidant activities of the entire oils

The essential oils of Ocimum basilicum L., Origanum vulgare L., and Thymus vulgaris L. were analyzed by means of gas chromatography-mass spectrometry and assayed for their antioxidant and antimicrobial activities. The antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with effects on lipid peroxidation (LP). RSC was assessed measuring the scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazil (DPPH(*)) and OH(*) radicals. Effects on LP were evaluated following the activities of essential oils in Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. Essential oils exhibited very strong RSCs, reducing the DPPH radical formation (IC(50)) in the range from 0.17 (oregano) to 0.39 microg/mL (basil). The essential oil of T. vulgaris exhibited the highest OH radical scavenging activity, although none of the examined essential oils reached 50% of neutralization (IC(50)). All of the tested essential oils strongly inhibited LP, induced either by Fe(2+)/ascorbate or by Fe(2+)/H(2)O(2). The antimicrobial activity was tested against 13 bacterial strains and six fungi. The most effective antibacterial activity was expressed by the essential oil of oregano, even on multiresistant strains of Pseudomonas aeruginosa and Escherichia coli. A significant rate of antifungal activity of all of the examined essential oils was also exhibited.     

不同海拔高度和竹龄对黄甜竹叶精油成分及其生物活性的影响

为探究海拔和竹龄对黄甜竹叶精油品质的影响,本研究采用气相色谱-质谱联用技术（GC-MS）测定不同海拔高度下新叶和老叶精油的化学成分,并分别采用平板抑菌法和1,1-二苯基-2-三硝基苯肼（DPPH）法测定各竹叶精油的抑菌效果和抗氧化活性。结果表明,黄甜竹叶精油中的成分以烷类、醇类、萜烯类和芳香族化合物为主,中高海拔有利于萜烯类化合物的合成和积累,新叶精油中的醇类、萜烯类和芳香族化合物含量高于老叶。各竹叶精油对干腐病菌（Fusarium）和葡萄座腔菌（Botryosphaeria dothidea）均有抑制效果,海拔越高竹叶的抑菌效果越好,新叶精油的抑菌效果强于老叶。各竹叶精油均表现出较高的抗氧化活性,表现为低海拔>中高海拔、新叶>老叶。本研究结果为黄甜竹叶资源的开发提供了数据支撑和新的利用方向。     

Antitermitic activity of leaf essential oils and components from Cinnamomum osmophleum

The antitermitic activities of the essential oils from the leaves of two Cinnamomum osmophloeumclones (A and B) and their chemical ingredients against Coptotermes formosanus Shiraki were investigated according to direct contact application. Results from this experiment have demonstrated that the indigenous cinnamon B leaf essential oil has a more effective antitermitic activity than indigenous cinnamon A leaf essential oil. Furthermore, when cinnamaldehyde, eugenol, and alpha-terpineol are extracted from indigenous cinnamon leaf essential oil and used at the strength of 1 mg/g, their antitermitic effectiveness is much higher than that using indigenous cinnamon leaf essential oil. Among the congeners of cinnamaldehyde examined, cinnamaldehyde has exhibited the strongest termiticidal property.     

Bioactive and Fragrant Constituents of Artemisia sieberi Besser Grown on Two Different Soil Types in Central Iran

The dried leaves and aerial parts of Artemisia sieberi Besser, which belongs to the Asteraceae family (Anthemideae) and grows in central Iran, were hydrodistilled to produce essential oils. The oil concentrations of the leaves and aerial parts were 0.32% and 0.79% (w/w), respectively. The essential oils were analyzed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). The amounts of the samples injected were 1.0 nL (diluted 1.0 μL of sample in 1000 ml of n-pentane, v/v). Twenty-three and 14 bioactive, flavor, and fragrance molecules were identified, representing 99.04% and 99.40% of the aerial parts’ essential oils from sites A and B, respectively. Aerial parts of the plants and the habitat soils were sampled at random in full flowering stages in a completely randomized (CR) design with three replications from two sites with different soil types. The main components were trans-methyl isoeugenol (32.60%) in the first site (A) and β-bisabolene (33.59%) in the second site (B) oils. The compositions of the oils were mostly quantitatively rather than qualitatively different.