Chemical composition and antimicrobial activity of the essential oils from the gum of Turkish pistachio (Pistacia vera L.)

The essential oil from the gum of Pistachio (Pistacia vera L. (Anacardiaceae)) grown in Turkey was obtained by the hydro-distillation method, and its chemical composition was analyzed by GC and GC-MS. Moreover, the antimicrobial activities of the oil against the growth of 13 bacteria and 3 pathogenic yeasts were evaluated using the agar-disk diffusion and minimum inhibitory concentration (MIC) methods. The results showed that the essential oil contained about 89.67% monoterpenes, 8.1% oxygenated monoterpenes and 1.2% diterpenes. alpha-Pinene (75.6%), beta-pinene (9.5%), trans-verbenol (3.0%), camphene (1.4%), trans-pinocarveol (about 1.20%), and limonene (1.0%) were the major components. The antimicrobial results showed that the oil inhibited nine bacteria and all the yeasts studied, and the activities were considerably dependent upon concentration and its bioactive compounds such as carvacrol, camphene, and limonene. Moreover, the essential oil of the gum was found to be more effective yeastcide than Nystatin, synthetic yeastcide. Furthermore, the antibacterial activities of the oil were lower than those of standard antibiotics, ampicillin sodium, and streptomycine sulfate under the conditions studied.     

Determination of the chemical composition and antioxidant activity of the essential oil of Artemisia dracunculus and of the antifungal and antibacterial activities of Turkish Artemisia absinthium, A. dracunculus, Artemisia santonicum, and Artemisia spicigera essential oils

The essential oil isolated from Turkish tarragon (Artemisia dracunculus) by hydrodistillation was analyzed by GC-MS. Thirty compounds representing 99.5% of total oil were identified. The predominant components in the oil were (Z)-anethole (81.0%), (Z)-beta-ocimene (6.5%), (E)-beta-ocimene (3.1%), limonene (3.1%), and methyleugenol (1.8%). The antibacterial and antifungal activities of the essential oils isolated from A. dracunculus, Artemisia absinthium, Artemisia santonicum, and Artemisia spicigera oils were also evaluated. In general, the oils exhibited potent antifungal activity at a wide spectrum on the growth of agricultural pathogenic fungi. Among the oils, the weakest antifungal activity was shown by the oil of A. dracunculus. In many cases, the oils of A. absinthium, A. santonicum, and A. spicigera completely inhibited the growth of some fungal species. As compared with antibacterial activities of all of tested oils, A. santonicum and A. spicigera oils showed antibacterial activities over a very wide spectrum. However, the essential oils tested showed lower inhibition zones than the inhibition zones of penicillin. In addition, antioxidant and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of tarragon oil were determined, and weak antioxidant and DPPH radical scavenging activities were found in comparison to butylated hydroxytoluene.     

花椒精油的萃取及生物活性成分应用研究进展

花椒精油是从花椒果壳、叶等部位所提取的植物精油,其独特的香气和麻味以及多种生物活性物质除了传统的调味用途外,还具有灭菌、杀虫、保鲜、药理等多种作用。为了给畜牧健康养殖、安全保鲜及花椒精油的进一步开发利用提供更多思路和支撑。通过查阅相关文献,归纳总结了花椒精油的主要成分、提取方式、微胶囊制备工艺以及生物活性抗菌、保鲜、药理等研究现状。花椒精油优秀的广谱抗菌效应和保鲜作用结合花椒精油微胶囊制备工艺可以更好地保留其生物活性,不仅可广泛地应用于食品调味、果蔬保鲜等方面,在我国畜牧业向全面无抗养殖发展的背景下,作为优良的植物来源保鲜剂和替代抗生素添加剂,在畜牧业杀虫灭菌、健康养殖、肉产品货架期保鲜等环节也有着广阔的应用前景。     

Composition and antibacterial activity of Pseudocytisus integrifolius (Salisb.) essential oil from Algeria

The essential oil composition of an endemic Algerian Cruciferae, Pseudocytisus integrifolius (Salisb.) Rehder, was analyzed by gas chromatography (GC) and GC-mass spectrometry (MS). Eighty-three components representing more than 96.5% of the oil were identified. The major components were dimethyl disulfide (33.4%), dimethyl trisulfide (24.2%), and an unsaturated nitrile (31.7%). Fractionation on a silica gel column led to the identification of trace-level compounds, in particular, polar compounds such as nitriles and aldehydes, and to the isolation of dimethyl disulfide, dimethyl trisulfide, and an unsaturated nitrile. Structural analysis using high-resolution mass spectrometry (HRMS) and 1H,13C NMR techniques enabled the identification of pent-4-enenitrile. Variation in essential oil composition and yields was studied according to harvesting time, drying, and parts of the plant. The essential oil of aerial parts was tested for its antibacterial activity using a paper disk method. The oil was effective on the inactivation of Escherichia coli and Pseudomonas aeruginosa and ineffective on the inactivation of Staphylococcus aureus.     

Chemical composition and antimicrobial and antioxidant activities of the essential oil and methanol extract of Hippomarathrum microcarpum (Bieb.) from Turkey

Hippomarathrum microcarpum grows wild in eastern Anatolia, Turkey, and is a plant utilized as food by people. In this study, the in vitro antimicrobial and antioxidant activities of the essential oil and methanol extract from H. microcarpum and its essential oil composition were investigated. The essential oil, which has bornyl acetate, caryophyllene oxide, and beta-caryophyllene as its main components, exhibited activity against eight bacteria, nine fungi, and a yeast, Candida albicans, with minimum inhibitory concentration values ranging from 62.50 to 125 muL/mL; the methanol extract showed weak activity. The antioxidant activity of these extracts was assessed by the beta-carotene bleaching test and the 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test. The inhibition of linoleic acid oxidation was very weak for both extracts tested. The inhibition percentages were found to be 22.9 and 33.5% for methanol and essential oil, respectively, at the concentration of 2 g/L. The oil scavenged DPPH at higher concentrations (IC50 = 10.69 +/- 0.05 mg/mL), but the methanol extract exhibited no activity. The total phenolic content of the methanol extract was found to be 4.7 +/- 0.1%.     

Antimicrobial and antioxidant activity of the essential oil and methanol extracts of Thymus pectinatus Fisch. et Mey. Var. pectinatus (Lamiaceae)

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.     

Identification of antioxidants in essential oil of radix Angelicae sinensis using HPLC coupled with DAD-MS and ABTS-based assay

Radix Angelicae sinensis (named danggui in Chinese), a commonly used traditional Chinese medicine, has multiple pharmacological activities. The essential oil of danggui is usually considered to be its main active fraction. However, to date, studies on the antioxidant potentials of danggui have focused on water-soluble compounds. In this paper, the antioxidant activity of the commercial essential oil of danggui was investigated by DPPH radical scavenging assay, ABTS radical scavenging assay, and beta-carotene bleaching test. Antioxidant constituents in the essential oil were identified using HPLC coupled with DAD-MS and ABTS-based assay. The results showed that the essential oil of danggui has concentration-dependent antioxidant activity, which can be attributed to its component (coniferyl ferulate). This is the first report on the antioxidant activity of essential oil from danggui; its antioxidant potential was lower than those of positive controls, ascorbic acid and BHA.     

(E)-Methylisoeugenol and elemicin: antibacterial components of Daucus carota L. essential oil against Campylobacter jejuni

The essential oil of wild Daucus carota L. obtained from aerial parts at the end of the flowering stage (DCEO) was reported as antimicrobial against the human enteropathogen Campylobacter jejuni. The aim of the present study was to extend this analysis to other Campylobacter species and to identify the active compounds of the essential oil, subjected to GC, GC-MS, and (13)C NMR analysis. A minimum inhibitory concentration assay was used to quantify the antimicrobial activity of DCEO and the major components, isolated on column chromatography. Growth of all the C. jejuni, Campylobacter coli, and Campylobacter lari strains tested, including one multidrug resistant C. jejuni, was inhibited to the same extent by DCEO. Molecules that were responsible for the antibacterial activity were identified as (E)-methylisoeugenol and elemicin. Moreover, the use of structural analogues of these compounds allowed us to identify important features that may account for the activity.     

Antibacterial properties and major bioactive components of cinnamon stick (Cinnamomum burmannii): activity against foodborne pathogenic bacteria

Cinnamomum burmannii Blume (cinnamon stick) from Indonesia is a little-investigated spice. In this study, the antibacterial activity, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of cinnamon stick extract were evaluated against five common foodborne pathogenic bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella anatum). Cinnamon stick extract exhibited significant antibacterial properties. Major compounds in cinnamon stick were tentatively identified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC-MS) as a predominant volatile oil component ((E)-cinnamaldehyde) and several polyphenols (mainly proanthocyanidins and (epi)catechins). Both (E)-cinnamaldehyde and proanthocyanidins significantly contributed to the antibacterial properties. Additionally, scanning electron microscopy was used to observe morphological changes of bacteria treated with the crude extract of cinnamon stick and its major components. This study suggests that cinnamon stick and its bioactive components have potential for application as natural food preservatives.     

Composition, enantiomeric distribution, and antibacterial activity of the essential oil of Achillea ligustica All. from Corsica

The essential oil of Achillea ligustica from Corsica was investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). A total of 82 compounds representing 94.0% of the oil were tentatively identified. The main constituents were the camphane derivatives, representing >30% (camphor, 21.3%; borneol, 6.2%; bornyl acetate, 3.5%) of the whole oil, and santolina alcohol (19.3%). The enantiomeric distribution of 8 chiral constituents was determined by GC-MS using two enantioselective stationary phases (DIME-beta-CD and Lipodex-E). Racemic santolina alcohol, required for optimization of the enantioselective GC conditions, was prepared by an original two-step synthesis from 2,5-dimethylhexa-2,4-diene. The whole essential oil was tested for its antibacterial activity against a wide range of bacteria using a paper disk method. The results show a promising activity against Streptomyces species.     

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.     

Investigation of the Origanum onites L. essential oil using the chorioallantoic membrane (CAM) assay

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.     

Impact of physicochemical characteristics on the oxidative stability of fish oil microencapsulated by spray-drying

The aim of the present research was to identify principal parameters determining the oxidative stability of microencapsulated fish oil. Microcapsules were prepared by spray-drying using different types of n-octenylsuccinate-derivatized starch, gum Arabic, sugar beet pectin, sodium caseinate, and/or glucose syrup. Two principal components to classify the different microcapsules accounting for up to 79% of the variance were identified. The principal components were determined by physicochemical parameters reflecting the emulsifying ability of the encapsulant and the drying behavior of the parent emulsion. Microcapsules, which were identified by principal component analysis to be significantly different, exhibited a low stability upon storage, showing that the principal components and, thus, the underlying physicochemical parameters analyzed in the present study are correlated with core material stability.     

Bioactivity of Backhousia citriodora: antibacterial and antifungal activity

Backhousia citriodora products are used as bushfoods and flavorings and by the aromatherapy industry. The antimicrobial activity of 4 samples of B. citriodora oil, leaf paste, commercial tea (0.2 and 0.02 g/mL), and hydrosol (aqueous distillate) were tested against 13 bacteria and 8 fungi. Little or no activity was found to be associated with the leaf tea and hydrosol, respectively. Leaf paste displayed antimicrobial activity against 7 bacteria including Clostridium perfringens, Pseudomonas aeruginosa, and a hospital isolate of methicillin resistant Staphylococcus aureus (MRSA). The 4 essential oils were found to be effective antibacterial and antifungal agents; however, variation was apparent between oils that did not correlate with citral content. The antimicrobial activity of B. citriodoraessential oils was found to be greater than that of citral alone and often superior to Melaleuca alternifolia essential oil. B. citriodora has significant antimicrobial activity that has potential as an antiseptic or surface disinfectant or for inclusion in foods as a natural antimicrobial agent.     

Composition,quality control,and antimicrobial activity of the essential oil of long-time stored dill (Anethum graveolens L.) seeds from Bulgaria

The essential oil of long-time stored seeds of dill (Anethum graveolens L.) from Bulgaria was analyzed by physicochemical methods, gas chromatography (GC), GC-mass spectrometry (MS) (achiral and chiral phases), and olfactometry, and its antimicrobial activity was tested by using different strains of microorganisms. More than 40 constituents of the essential dill oil, obtained from seeds stored for more than 35 years, could be identified as essential volatiles, responsible for the pleasant fresh (D-limonene) and spicy (D-carvone) odor of a high quality. As aroma impact compounds, D-carvone (50.1%) and D-limonene (44.1%) were found. Antimicrobial testings showed high activity of the essential A. graveolens oil against the mold Aspergillus niger and the yeasts Saccharomyces cerevisiae and Candida albicans.     

Bacterial susceptibility to and chemical composition of essential oils from Thymus kotschyanus and Thymus persicus

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.     

Chemical composition and antioxidant properties of clove leaf essential oil

The antioxidant activity of a commercial rectified clove leaf essential oil (Eugenia caryophyllus) and its main constituent eugenol was tested. This essential oil comprises in total 23 identified constituents, among them eugenol (76.8%), followed by beta-caryophyllene (17.4%), alpha-humulene (2.1%), and eugenyl acetate (1.2%) as the main components. The essential oil from clove demonstrated scavenging activity against the 2,2-diphenyl-1-picryl hydracyl (DPPH) radical at concentrations lower than the concentrations of eugenol, butylated hydroxytoluene (BHT), and butylated hydroxyanisole (BHA). This essential oil also showed a significant inhibitory effect against hydroxyl radicals and acted as an iron chelator. With respect to the lipid peroxidation, the inhibitory activity of clove oil determined using a linoleic acid emulsion system indicated a higher antioxidant activity than the standard BHT.     

In vitro antibacterial,antifungal, and antioxidant activities of the essential oil and methanol extracts of herbal parts and callus cultures of Satureja hortensis L

The present study was designated to evaluate the antimicrobial and antioxidant activities of the essential oil, obtained by using a Clevenger distillation apparatus, water soluble (polar) and water insoluble (nonpolar) subfractions of the methanol extracts from aerial parts of Satureja hortensis L. plants, and methanol extract from calli established from the seeds using Gamborg's B5 basal media supplemented with indole-3-butyric acid (1.0 ppm), 6-benzylaminopurine (N(6)-benzyladenine) (1.0 ppm), and sucrose (2.5%). The antimicrobial test results showed that the essential oil of S. hortensis had great potential antimicrobial activities against all 23 bacteria and 15 fungi and yeast species tested. In contrast, the methanol extract from callus cultures and water soluble subfraction of the methanol extract did not show antimicrobial activities, but the nonpolar subfraction had antibacterial activity against only five out of 23 bacterial species, which were Bacillus subtilis, Enterococcus fecalis, Pseudomonas aeruginosa, Salmonella enteritidis, and Streptococcus pyogenes. Antioxidant studies suggested that the polar subfractions of the methanol extract of intact plant and methanol extract of callus cultures were able to reduce the stable free radical 2,2-diphenyl-1-picrylhydrazyl to the yellow-colored diphenylpicrylhydrazine. In this assay, the strongest effect was observed for the tissue culture extract, with an IC(50) value of 23.76 +/- 0.80 microgram/mL, which could be compared with the synthetic antioxidant agent butylated hydroxytoluene. On the other hand, linoleic acid oxidation was 95% inhibited in the presence of the essential oil while the inhibition was 90% with the chloroform subfraction of the intact plant. The chemical composition of a hydrodistilled essential oil of S. hortensis was analyzed by gas chromatography (GC)/flame ionization detection (FID) and a GC-mass spectrometry system. A total 22 constituents representing 99.9% of the essential oil were identified by GC-FID analaysis. Thymol (29.0%), carvacrol (26.5%), gamma-terpinene (22.6%), and p-cymene (9.3%) were the main components.     

Composition and functional properties of the essential oil of amazonian basil, Ocimum micranthum Willd., Labiatae in comparison with commercial essential oils

Wild Amazonian basil Ocimum micranthum Willd. (O. campechianum Mill.) Labiatae essential oil was analyzed by GC and GC-MS: 31 compounds were identified. The main components were eugenol (46.55 +/- 5.11%), beta-caryophyllene (11.94 +/- 1.31%), and beta-elemene (9.06 +/- 0.99%), while a small amount of linalool (1.49 +/- 0.16%) was detected. The oil was tested for its in vitro food-related biological activities and compared with common basil Ocimum basilicum and Thymus vulgaris commercial essential oils. Radical scavenging activity was evaluated employing 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. The oil exerted a good capacity to act as a nonspecific donor of hydrogen atoms or electrons when checked in the diphenylpicrylhydrazyl assay, quenching 76,61 +/- 0.33% of the radical, with values higher than those reported by reference oils. In the beta-carotene bleaching test, the oil provided an antioxidant efficacy comparable with that of O. basilicum and T. vulgaris essential oils. These data were confirmed by photochemiluminescence, where the oil showed a remarkable antioxidant capacity (2.39 +/- 0.1), comparable to that of Trolox and vitamin E, and higher than the other essential oils. Antibacterial activity of O. micranthum essential oil was evaluated against Gram positive and Gram negative bacterial strains. The oil showed a dose-dependent antifungal activity against pathogenic and food spoiling yeasts.     

Antioxidant and biocidal activities of Carum nigrum (seed) essential oil, oleoresin, and their selected components

In the present study, chemical constituents of the essential oil and oleoresin of the seed from Carum nigrum obtained by hydrodistillation and Soxhlet extraction using acetone, respectively, have been studied by GC and GC-MS techniques. The major component was dillapiole (29.9%) followed by germacrene B (21.4%), beta-caryophyllene (7.8%), beta-selinene (7.1%), and nothoapiole (5.8%) along with many other components in minor amounts. Seventeen components were identified in the oleoresin (Table 2) with dillapiole as a major component (30.7%). It also contains thymol (19.1%), nothoapiole (15.2.3%), and gamma-elemene (8.0%). The antioxidant activity of both the essential oil and oleoresin was evaluated in mustard oil by monitoring peroxide, thiobarbituric acid, and total carbonyl and p-anisidine values of the oil substrate. The results showed that both the essential oil and oleoresin were able to reduce the oxidation rate of the mustard oil in the accelerated condition at 60 degrees C in comparison with synthetic antioxidants such as butylated hydroxyanisole and butylated hydroxytoluene at 0.02%. In addition, individual antioxidant assays such as linoleic acid assay, DPPH scavenging activity, reducing power, hydroxyl radical scavenging, and chelating effects have been used. The C. nigrum seed essential oil exhibited complete inhibition against Bacillus cereus and Pseudomonas aeruginosa at 2000 and 3000 ppm, respectively, by agar well diffusion method. Antifungal activity was determined against a panel of foodborne fungi such as Aspergillus niger, Penicillium purpurogenum, Penicillium madriti, Acrophialophora fusispora, Penicillium viridicatum, and Aspergillus flavus. The fruit essential oil showed 100% mycelial zone inhibition against P. purpurogenum and A. fusispora at 3000 ppm in the poison food method. Hence, both oil and oleoresin could be used as an additive in food and pharmaceutical preparations after screening.