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1.
The essential oil, obtained by using a Clevenger distillation apparatus, and water-soluble (polar) and water-insoluble (nonpolar) subfractions of the methanol extract of Thymus pectinatus Fisch. et Mey. var. pectinatus were assayed for their antimicrobial and antioxidant properties. No (or slight) antimicrobial activity was observed when the subfractions were tested, whereas the essential oil showed strong antimicrobial activity against all microorganisms tested. Antioxidant activities of the polar subfraction and the essential oil were evaluated using 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide radical scavenging, and lipid peroxidation assays. The essential oil, in particular, and the polar subfraction of the methanol extract showed antioxidant activity. The essential oil was analyzed by GC/MS, and 24 compounds, representing 99.6% of the essential oil, were identified: thymol, gamma-terpinene, p-cymene, carvacrol, and borneol were the main components. An antimicrobial activity test carried out with fractions of the essential oil showed that the activity was mainly observed in those fractions containing thymol, in particular, and carvacrol. The activity was, therefore, attributed to the presence of these compounds. Other constituents of the essential oil, such as borneol, gamma-terpinene, and p-cymene, could be also taken into account for their possible synergistic or antagonistic effects. On the other hand, thymol and carvacrol were individually found to possess weaker antioxidant activity than the crude oil itself, indicating that other constituents of the essential oil may contribute to the antioxidant activity observed. In conclusion, the results presented here show that T. pectinatus essential oil could be considered as a natural antimicrobial and antioxidant source.  相似文献   

2.
The in vivo test on the chorioallantoic membrane of the fertilized hen's egg (CAM assay) is a current method to determine antiangiogenic, antiinflammatory activity and toxic effects of individual compounds or complex plant extracts. The method is used for testing natural compounds in small amounts for revealing various modes of action and the complex mechanisms related to angiogenesis and inflammation. Furthermore, possible side effects such as membrane irritation, toxic, and anticoagulant properties of the investigated material in question can be detected. For the evaluation, the essential oil obtained by hydrodistillation of the aerial parts of Origanum onites L., a common spice and medicinal plant, was tested for its effect in the chorioallantoic membrane (CAM) assay. The essential oil composition was revealed by means of gas chromatography-mass spectrometry (GC-MS). Eighty three components were identified, representing 99.1% of the total oil. Carvacrol, thymol, p-cymene, and gamma-terpinene were found as major components and were also individually tested in the CAM assay. Along with the monoterpenes carvacrol and thymol, their methyl ether derivatives were also examined for comparison of their physiological action. Neither the essential oil nor its components showed any pronounced antiinflammatory or antiangiogenic property in the CAM assay, at 10-250 microg/pellet. However, the irritant effect of the essential oil was linked to thymol in a dose-response fashion, up to 10 microg/pellet, where it was still showing irritation.  相似文献   

3.
The present study was carried out to investigate the modulating effects of thyme and its major components against the oxidative DNA damage induced by H(2)O(2). The human lymphocytes with thymol, carvacrol, and gamma-terpinene incubated with or without 0.1 mM H(2)O(2) for 30 min at 37 degrees C and the DNA damage were evaluated by singe cell gel electropheresis (comet assay). Concentrations above 0.1 mM thymol and gamma-terpinene and 0.05 mM carvacrol significantly induced DNA damage in human lymphocytes, but at the smaller concentrations no additional DNA strand breakage has been observed. At the all concentrations studied, gamma-terpinene did not show any protective effect against H(2)O(2) induced oxidative DNA damage, but the phenolic compounds thymol and carvacrol at concentrations below 0.2 and 0.1 mM, respectively, significantly reduced the oxidative DNA damage (p < 0.001). The n-hexane and ethyl acetate fractions prepared from the methanolic extracts of Thymus spicata also were found to inhibit DNA damage.  相似文献   

4.
The composition of the essential oils of Origanum and Thymus species restricted to Algeria and the North Africa region was determined. Antioxidant and antibacterial activities of the isolated essential oils were also determined. The oils of oregano plants were strongly characterized by p-cymene (16.8-24.9%), gamma-terpinene (16.8-24.9%), thymol (8.4-36.0%), and carvacrol (1.1-29.7%), a thymol chemotype for Origanum floribundum and a alpha-terpineol chemotype for Thymus numidicus being described for the first time. The strains of Listeria monocytogenes tested were relatively resistant to the action of essential oils of either Origanum or Thymus species. All essential oils possessed antioxidant activity, but this was dependent on the specific chemical composition and the method employed to determine such activity.  相似文献   

5.
Antilisterial activities of Thymbra capitata and Origanum vulgare essential oils were tested against 41 strains of Listeria monocytogenes. The oil of T. capitata was mainly constituted by one component, carvacrol (79%), whereas for O. vulgare three components constituted 70% of the oil, namely, thymol (33%), gamma-terpinene (26%), and p-cymene (11%). T. capitata essential oil had a significantly higher antilisterial activity in comparison to O. vulgare oil and chloramphenicol. No significant differences in L. monocytogenes susceptibilities to the essential oils tested were registered. The minimum inhibitory concentration values of T. capitata essential oil and of carvacrol were quite similar, ranging between 0.05 and 0.2 microL/mL. Antioxidant activity was also tested, the essential oil of T. capitata showing significantly higher antioxidant activity than that of O. vulgare. Use of T. capitata and O. vulgare essential oils can constitute a powerful tool in the control of L. monocytogenes in food and other industries.  相似文献   

6.
Volatile oil extracts of fennel seeds (Foeniculum vulgare Mill.) and thyme leaves (Thymus vulgaris L.) were obtained by simultaneous distillation-extraction (SDE) and supercritical fluid extraction (SFE) and analyzed by gas chromatography-mass spectrometry (GC-MS). In general, fennel oil extracted by SDE and SFE showed similar compositions, with trans-anethole, estragole, and fenchone as the main components. In contrast, thymol and p-cymene, the most abundant compounds in thyme leaves, showed big differences, with generally higher amounts of monoterpenes obtained by SDE. However, in this case, the differences between the extracts were higher. Key odorants of fennel seeds determined by gas chromatography-olfactometry (GC-O) showed similar patterns when applying SDE and SFE. trans-Anethole (anise, licorice), estragole (anise, licorice, sweet), fenchone (mint, camphor, warm), and 1-octen-3-ol (mushroom) were the most intense odor compounds detected in fennel extracts. Thymol and carvacrol, with oregano, thyme, and spicy notes, were identified as key compounds contributing to the aroma of thyme leaves.  相似文献   

7.
Susceptibility of Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia, and Pseudomonas aeroginosa to the essential oils extracted from two varieties of Thyme, i.e., Thymus kotschyanus Boiss. and Hohen. and Thymus persicus L. at preflowering and flowering stages were studied. The disk diffusion method was used to evaluate the zone of microbial growth inhibition at various concentrations of the oils. Minimal inhibitory concentration and minimal bactericidal concentration of the oils were determined and compared with each other. The oils from the above plants were found to be strongly bactericidal with that of T. kotschyanus being more effective. T. kotschyanusand T. persicus oils analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) lead to identification of 33 and 26 components, respectively. The profile of the oil components from T. persicuswas similar to that of T. kotschyanus in almost all of the compounds but at different concentrations. The major components of T. kotschyanus oil before and at the flowering stages were carvacrol (35.06, 22.75%), thymol (26.60, 16.52%), gamma-terpinene (7.81, 0.34%), gamma-terpinene (4.34, 0%), borneol (2.29, 4.52%), myrcene (0.26, 12.65%), thymolquinone (0, 11.39%), nerol (0, 6.10%), and beta-caryophyllene (0, 5.54%), respectively, and those of T. persicus at the same stages were carvacrol (38.96, 27.07%), thymol (6.48, 11.86%), P-cymene (7.51, 10.16%), gamma-terpineol (0, 9.51%), nerol (15.66, 9.41%), gamma-terpinene (6.11, 6.51%), and thymol acetate (5.29, 5.30%), respectively. The contribution of oil components to its antibacterial property is discussed. High aromatic compound content of the phenol-rich oils seems to account for strong antibacterial activity.  相似文献   

8.
Thymus pulegioides L. with lemon and carvacrol odor form the major part of plants growing wild in all 10 investigated localities during 1995-1997. The main components of the citral-geraniol chemotype of lemon-scented essential oil are the following (%): geraniol (14.9-30. 8), geranial (trans-citral, 9.7-19.7), beta-caryophylene (6.0-11.4), nerol (4.1-11.8), and neral (cis-citral, 0.1-9.5). The essential oil of carvacrol chemotypes contain more compounds that are characteristic of the thyme genus (%): carvacrol (16.0-22.2), beta-bisabolene (11.1-20.2), beta-caryophyllene (11.1-19.1), gamma-terpinene (5.8-16.2), p-cimene (5.5-10.4), thymol (3.3-9.8), and carvacrol methyl ether (5.6-8.6). The correlation between the odor and composition of the essential oil will help the users of wild thyme to choose the necessary chemotype for their purposes.  相似文献   

9.
The essential oil composition and genetic variability of six commercial cultivars of thyme (Thymus vulgaris L.), a Mediterranean medicinal and aromatic plant, were analyzed by GC-MS and randomly amplified polymorphic DNA (RAPD), respectively. All evaluated cultivars belong to the thymol chemotype, with differences in the concentrations of thymol, gamma-terpinene, p-cymene, and other minor components. The comparison of the oil components concentration by multivariate analysis allowed separation of the cultivars into two groups. All of the cultivars exhibited characteristic RAPD patterns that allowed their identification. On the basis of the RAPD patterns, the cultivars could be divided into two clusters, which coincides with results obtained by oil GS-MS analysis, with a correlation coefficient of -0.779.  相似文献   

10.
We evaluated the insecticidal and acetylcholine esterase (AChE) inhibition activity of 11 Apiaceae plant essential oils and their constituents in adult male and female Blattella germanica. Of the 11 Apiaceae plant essential oils tested, dill (Anethum graveolens), carvi (Carum carvi), and cumin (Cuminum cyminum) demonstrated >90% fumigant toxicity against adult male German cockroaches at a concentration of 5 mg/filter paper. In a contact toxicity test, dill (Anethum graveolens), carvi (Carum carvi), cumin (Cuminum cyminum), and ajowan (Trachyspermum ammi) produced strong insecticidal activity against adult male and female German cockroaches. Among the test compounds, (S)-(+)-carvone, 1,8-cineole, trans-dihydrocarvone, cuminaldehyde, trans-anethole, p-cymene, and γ-terpinene demonstrated strong fumigant toxicity against adult male and female B. germanica. In a contact toxicity test, carveol, cuminaldehyde, (S)-(+)-carvone, trans-anethole, thymol, and p-cymene showed strong contact toxicity against adult male and female B. germanica. IC(50) values of α-pinene, carvacrol, and dihydrocarvone against female AChE were 0.28, 0.17, and 0.78 mg/mL, respectively. The toxicity of the blends of constituents identified in 4 active oils indicated that carvone, cuminaldehyde, and thymol were major contributors to the fumigant activity or contact toxicity of the artificial blend.  相似文献   

11.
The effect exerted by two structurally similar limonoids possessing antifeedant and anticancer activity, limonin and nomilin, on the thermotropic behavior of model membranes constituted by dimyristoylphosphatidylcholine (DMPC) vesicles was studied by differential scanning calorimetry. Attention was directed to evaluate modifications in phytochemical-lipid interaction induced by compound structure and lipophilicity and to evidence their different membrane penetration. The two examined compounds, when dispersed in liposomes during their preparation, were found to exert a very different action on the L(beta)-L(alpha) gel-to-liquid crystal phase transition of DMPC multilamellar vesicles. Nomilin caused a detectable effect on the transition temperature (T(m)), shifting it toward lower values with a concomitant small decrease of the associated enthalpy (DeltaH) changes, while limonin was not able to modify the lipid vesicles thermotropic behavior. Modifications induced by nomilin were a function of phytochemical concentration, while the different behavior of limonin can be due to the different polarity induced by the presence of the single A ring in nomilin that possesses an acetyl group versus the A,A' ring system of limonin. Solid limonoids and aqueous dispersions of multilamellar (MLVs) or unilamellar vesicles (LUVs) (limonoids molar fraction 0. 045, 0.12, and 0.18) were left in touch for long incubation times at temperatures higher than T(m) to detect their spontaneous transfer through the medium. By following this procedure, no interaction was detected for limonin with lipid vesicles. The rate of transfer and interaction of nomilin was a function of the kind of vesicle species (faster for LUV, slower for MLV). The interaction, monitored by compound transfer from the solid phytochemical to the lipidic species after several periods of incubation, was on the same order as that detected by preparation carried out in organic solvent. The obtained results can be explained in terms of compound hydrophobicity, and a relation between compound structure and membrane interaction can be suggested. This allows the membrane interaction with nomilin, but the low water solubility of limonin hinders or totally blocks its transfer through the aqueous medium.  相似文献   

12.
Membrane toxicity of antimicrobial compounds from essential oils   总被引：2，自引：0，他引：2  
Natural antimicrobial compounds perform their action mainly against cell membranes. The aim of this work was to evaluate the interaction, meant as a mechanism of action, of essential oil antimicrobial compounds with the microbial cell envelope. The lipid profiles of Escherichia coli O157:H7, Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Pseudomonas fluorescens, and Brochothrix thermosphacta cells treated with thymol, carvacrol, limonene, eugenol, and cinnamaldehyde have been analyzed by gas chromatography. In line with the fatty acids analysis, the treated cells were also observed by scanning electron microscopy (SEM) to evaluate structural alterations. The overall results showed a strong decrease of the unsaturated fatty acids (UFAs) for the treated cells; in particular, the C18:2trans and C18:3cis underwent a notable reduction contributing to the total UFA decreases, while the saturated fatty acid C17:0 raised the highest concentration in cinnamaldehyde-treated cells. SEM images showed that the used antimicrobial compounds quickly exerted their antimicrobial activities, determining structural alterations of the cell envelope.  相似文献   

13.
This study was conducted to determine the lipolytic effects of eight kinds of citrus peel oils and their components. All of the citrus peel oils revealed lipolytic effects on olive oil model solution ranging from 10.9 to 73.8%. Hakyul (Citrus natsudaidai Hayata) showed the highest lipolytic effect (73.8%), followed by yuza (Citrus junos Sieb. ex Tanaka, 68.1%) and lemon (Citrus limonium, 63.4%), and their effects were comparable with or stronger than that of 5 mM raspberry ketone (p < 0.05). Among 17 authentic compounds relating to citrus peel oils, octanal (78.6%) showed the highest lipolytic effect, followed by gamma-terpinene (76.3%), limonene (75%), terpinen-4-ol (70.7%), nerol (69.9%), p-cymene (67.7%), and geranyl acetate (67.2%), and their effects were stronger than that of 5 mM raspberry ketone (p < 0.05). Ethyl acetate, alpha-pinene, myrcene, citronellal, linallyl acetate, and citronellol exhibited poor lipolytic effect in the model solution. Lipolytic effect was found to be high when the oils included a higher content of gamma-terpinene and p-cymene. Limonene showed potential lipolytic effect, and its effect is likely to be enhanced by the presence of gamma-terpinene and p-cymene. It is considered that monoterpene hydrocarbons consisting of one or two double bonds would have stronger lipolytic effect than those having three double bonds.  相似文献   

14.
Characteristic aroma components of water dropwort (Oenanthe javanica DC.) were evaluated by aroma extract dilution analysis and solid-phase microextraction-gas chromatography-olfactometry. Alpha-Terpinolene (plastic/cucumber-like) was the most intense aroma-active compound in water dropwort. Other potent aroma-active compounds included p-cymene (kerosene-like), alpha-terpinene (lemon), (E)-caryophyllene (woody), (Z,E)-alpha-farnesene (woody), hexanal (green), (Z)-3-hexenol (green), phenylacetaldehyde (honey), (E)-2-nonenal (cucumber), bornyl acetate (cooked vegetable), and gamma-terpinene (lemon). Of these, p-cymene was believed to be primarily responsible for the distinct kerosene-like aroma note of water dropwort. The aroma property of p-cymene was dependent on its concentration and was described as kerosene-like at relatively high concentrations but changed to citrus and green aroma notes at low concentrations.  相似文献   

15.
Phenolics antioxidant phytochemicals have been recently implicated for the lower rates of cardiac disease mortality among people consuming a Mediterranean diet. Essential oils are natural products extracted from vegetable materials, which can be used as antibacterial, antifungal, antioxidants, and anti-carcinogenic agents or to preserve and give specific flavors to foods. The activities of 23 selected essential oils in inhibiting the copper-catalyzed oxidation of human-low-density lipoproteins (LDL) were determined in vitro. LDL oxidation was inhibited between 6, 2, and 83% by 2 microM (GAE) total phenolics. The relative inhibition of LDL oxidation was used to categorize the essential oils into four groups below 2% when they contained methylchavicol, anethol, p-cymen, apiole, cinnamic ether; 6-10% if they possessed a majority of carvacrol, thymol, p-cymene, or vanillin; 10-50% for moderate amounts of thymol, carvacrol, cuminol, or eugenol; and 50-100% when eugenol is the major component. Total phenol content of essential oils gave a correlation with LDL antioxidant activity of r = 0.75. The Activity of each phenolics compound could play a role in protecting LDL against oxidation if the substance is absorbed by the body.  相似文献   

16.
GC and GC-MS analysis of ajwain essential oil showed the presence of 26 identified components which account for 96.3% of the total amount. Thymol (39.1%) was found as a major component along with p-cymene (30.8%), gamma-terpinene (23.2%), beta-pinene (1.7%), terpinene-4-ol (0.8%) whereas acetone extract of ajwain showed the presence of 18 identified components which account for 68.8% of the total amount. The major component was thymol (39.1%) followed by oleic acid (10.4%), linoleic acid (9.6%), gamma-terpinene (2.6%), p-cymene (1.6%), palmitic acid (1.6%), and xylene (0.1%). Moreover, the oil exhibited a broad spectrum of fungitoxic behavior against all tested fungi such as Aspergillus niger, Aspergillus flavus, Aspergillus oryzae, Aspergillus ochraceus, Fusarium monoliforme, Fusarium graminearum, Pencillium citrium, Penicillium viridicatum, Pencillium madriti, and Curvularia lunata as absolute mycelial zone inhibition was obtained at a 6-microL dose of the oil. However, the acetone extract showed better antioxidative activity for linseed oil as compared with synthetic antioxidants such as butylated hydroxyl toluene and butylated hydroxyl anisole.  相似文献   

17.
This study was designed to examine the in vitro antimicrobial and antioxidant activities of the essential oil and various extracts obtained from aerial parts of Thymus eigii. The essential oil was particularly found to possess stronger antimicrobial activity, whereas other nonpolar extracts and subfractions showed moderate activity and polar extracts remained almost inactive. GC-MS analysis of the oil resulted in the identification of 39 compounds, representing 93.7% of the oil; thymol (30.6%), carvacrol (26.1%), and p-cymene (13.0%) were the main components. The samples were also subjected to a screening for their possible antioxidant activity by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and beta-carotene-linoleic acid assays. In the former case, the polar subfraction of the methanol extract was found to be superior to all extracts tested, only 16.8 microg/mL of which provided 50% inhibition, whereas all extracts, particularly the polar ones, seem to inhibit the oxidation of linoleic acid in the latter case. These data were further supported by total phenolics analysis, indicating that the antioxidative potential of the extracts was closely related to their phenolic constituents.  相似文献   

18.
We carried out an investigation by differential scanning calorimetry (DSC) on the effect of two structurally similar bioactive plant phenols, cinnamic and p-coumaric acids, on the phase transition of model membranes constituted by dimyristoylphosphatidylcholine (DMPC) vesicles. The aim was to evaluate how pH and molecular substituents influence liposolubility and thereby modify vesicle permeability. A change in permeability would result in modifications to the phase transition for DMPC liposomes such that the transition temperature would be lowered and the enthalpy changes should be little affected. Evidence of differences in permeability was obtained by comparing the effects exerted by the two compounds left in touch with unilamellar and multilamellar vesicles, at two different pHs (4 and 7.4). While the p-coumaric acid was unable to appreciably modify the thermotropic behavior of the model membrane, the cinnamic acid interacted with lipid vesicles at both pH's, even if at acidic pH the effect was greater than neutral. It can be hypothesized that the interaction between the cinnamic acid and the lipidic layers is due to the lack of a hydroxyl group. This interaction is enhanced by an acidic pH, where the carboxylic acid is in a protonated form.  相似文献   

19.
Carvacrol is a component of several essential oils and has been shown to exert antimicrobial activity. The structural requirements for the activity of carvacrol were determined by comparison to structurally related (nonessential oil) compounds. Removal of the aliphatic ring substituents of carvacrol slightly decreased the antimicrobial activity. The effect of the hydroxyl group of carvacrol on activity could not be determined by simply comparing it to p-cymene, because this compound is immiscible with water; therefore, 2-amino-p-cymene, the amino analogue of carvacrol, which has a similar hydrophobicity and structural characteristics, was used. 2-Amino-p-cymene had similar membrane disruption and bacterial killing characteristics as carvacrol showing that, contrary to previous reports, the hydroxyl group of carvacrol itself is not essential for the antimicrobial activity. However, the observed 3-fold lower activity for 2-amino-p-cymene as compared to carvacrol indicates special features in the antimicrobial mode of action of carvacrol due to the hydroxyl group.  相似文献   

20.
Several naturally occurring essential oils including carvacrol, anethole, cinnamaldehyde, cinnamic acid, perillaldehyde, linalool, and p-cymene were evaluated for their effectiveness in reducing decay and increasing antioxidant levels and activities in 'Duke' blueberries ( Vaccinium corymbosum). Carvacrol, anethole, and perillaldehyde showed the capability to promote total anthocyanins and total phenolics and enhance antioxidant activity in fruit tissues expressed as oxygen radical absorbance capacity (ORAC) and hydroxyl radical ( (*)OH) scavenging capacity. All of the essential oils tested in this study were able to inhibit fruit decay development to some degree compared to controls. The most effective compound for mold retardation was p-cymene, followed by linalool, carvacrol, anethole, and perillaldehyde. Cinnamic acid and cinnamaldehyde also suppressed mold growth, but to a lesser extent. Treatment with carvacrol, anethole, or perillaldehyde also significantly increased the levels of fructose, glucose, and citric acid. Individual flavonoids were variably affected by the essential oils. Levels of chlorogenic acid, which was the major phenolic compound in blueberry fruit, were enhanced by all of the essential oils in this study. Increased amounts of quercetin 3-galactoside and quercetin 3-arabinoside were also found in all treated fruit except samples treated with linalool or p-cymene. The major anthocyanin, malvidin 3-galactoside, was enhanced by all essential oils tested except linalool and p-cymene. The levels of other individual anthocyanins including petunidin 3-galactoside, delphinidin 3-galactoside, petunidin 3-glucoside, petunidin 3-arabinoside, delphinidin 3-arabinoside, and cyanidin 3-galactoside were higher in treated fruit compared to controls. Those essential oils that have positive effects on enhancing anthocyanins, phenolic compounds, and antioxidant activity of fruit, but inhibitory effects on microbial growth and decay development, deserve further evaluation.  相似文献   

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