Chemical composition and antioxidant and antimicrobial activity of two Satureja essential oils

Hydro-distilled volatile oils from the aerial parts of Satureja montana L., and Satureja subspicata Bartl. ex Vis., growing wild in Bosnia and Herzegovina, were analyzed by GC/MS. More than one hundred compounds were identified in both plant oils, representing 92.4–98.1% of the total oil. The major constituents of essential oils obtained from the plant material of S. montana, collected from two different localities, were thymol (31.7%), and geraniol (22.3%), respectively. The most abundant compounds in essential oils of S. subspicata, collected at two different stages of development, were thymol (28.6%), and spathulenol (37.6%), respectively. The screening of antimicrobial activity of essential oil samples was individually evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis using a paper disc diffusion method. All tested microorganisms were inhibited by essential oil samples. Antioxidant activity was tested using the DPPH radical-scavenging method. All samples showed activity comparable to thymol, which was used as a positive probe.     

Chemical composition and antimicrobial activity of the essential oils from four Ruta species growing in Algeria

Antimicrobial properties of plants essential oils have been investigated in order to suggest them as potential tools to overcome the microbial drug resistance and the increasing incidence of food borne diseases problems. The aim of this research is to study the antibacterial and antifungal effects of four traditional plants essential oils, Ruta angustifolia, Ruta chalepensis, Ruta graveolens and Ruta tuberculata, against standard bacterial and fungal strains. The chemical compounds of the oils were examined by GC/MS. Results revealed a powerful antifungal activity against filamentous fungi. Aspergillus fumigatus and Cladosporium herbarum are the most sensitive strains to these oils with MIC values less than 3.5 μg ml⁻¹ for certain oils, reaching 7.8 μg ml⁻¹ for other. GC/MS essay exhibited ketones as the most abundant constituent of these oils except for R. tuberculata essential oil which has a completely different composition, monoterpenes alcohols being the most abundant. These compositions explain their potential antifungal activity.     

Chemical composition and antimicrobial properties of essential oils of three Australian Eucalyptus species

The chemical composition and antimicrobial properties of the essential oils of three common Australian Eucalyptus species, namely E. olida, E. staigeriana and E. dives were determined by gas chromatography/mass spectrometry and the agar disc diffusion method, respectively. A total of 24 compounds were identified from the essential oil of E. dives, with the dominant compounds being piperitone (40.5%), α-phellandrene (17.4%), p-cymene (8.5%) and terpin-4-ol (4.7%). For E. staigeriana, 29 compounds were identified with 1,8-cineole (34.8%), neral (10.8%), geranial (10.8%), α-phellandrene (8.8%) and methyl geranate (5.2%) being the dominant ones. In contrast, a single compound, (E)-methyl cinnamate, accounted for 99.4% of the essential oils of E. oilda, although 20 compounds were identified. The essential oils displayed a variable degree of antimicrobial activity with E. staigeriana oil showing the highest activity. In general, Gram-positive bacteria were found to be more sensitive to the essential oils than Gram-negative bacteria. Staphylococcus aureus was the most sensitive strain while Pseudomonas aeruginosa was the most resistant.     

Supercritical carbon dioxide extraction of carrot fruit essential oil: Chemical composition and antimicrobial activity

Isolation of carrot fruit (Daucus carrota L., cultivar “Chanteney”) essential oil by supercritical carbon dioxide was investigated from the pretreatment of herbaceous matrix and extraction conditions to the chemical composition of obtained extract and its antimicrobial activity. The qualitative and quantitative analyses of the supercritical extract, as well as of the essential oil obtained by hydrodistillation, were done by GC/FID and GC/MS methods. Antimicrobial properties of both samples were investigated against ten species of microorganisms. Experimental results showed that the particle size had no influence on the extraction process. The highest yield was obtained at 40 °C and 10 MPa. The main component of the supercritical extract, as well as of the essential oil was carotol. The supercritical extract was characterized by the presence of heavier molecular weight compounds, while some lighter compounds, e.g. pinenes, were not detected. The supercritical extract and the essential oil were the most effective against Gram-positive bacteria.     

Phytochemical composition and antimicrobial activities of the essential oils from Satureja subspicata Vis. growing in Croatia

The present study describes the phytochemical profile and antimicrobial activity of Satureja subspicata Vis. essential oils, collected in Dalmatia (Croatia). Three samples of essential oils were obtained from the aerial parts of the plant by hydrodistillation and analyzed by GC–MS. From the 24 compounds representing 97.47% of the oils, carvacrol (16.76%), α-pinene (13.58), p-cymene (10.76%), γ-terpinene (9.54%) and thymol methyl ether (8.83%) appear as the main components. The oils also contained smaller percentages of myrcene, linalool, β-caryophyllene, limonene, geranyl acetate, 1-Octen-3-ol, nerol, thymol and borneol. Furthermore, antimicrobial activity of the oil was evaluated using agar diffusion and broth microdilution methods. The antimicrobial test results showed that the oils had a great potential antimicrobial activity against all 13 bacteria and 9 fungal strains. Gram-positive bacteria are more sensitive to the investigated oil, with a range of 0.09 to 6.25 μl/ml than Gram-negative bacteria in the range which is significantly higher from 1.56 to 25.00 μl/ml. Results presented here may suggest that the essential oil of S. subspicata possesses antimicrobial properties, and is therefore a potential source of antimicrobial ingredients for the food and pharmaceutical industry.     

Composition and antimicrobial activity of essential oils of Cinnamosma fragrans

Essential oil samples of Cinnamosma fragrans from two regions in Madagascar, Tsaramandroso (38 samples) and Mariarano (30 samples), were analysed by GC/MS. Fifty-seven components were identified, accounting from 88.3% to 99.4% of the oils’ composition. The major components were linalool (72.5 ± 23.3%) in Tsaramandroso and 1,8-cineole (47.3 ± 10.2%) in Mariarano.     

Nanoencapsulation of essential oils to enhance their antimicrobial activity in foods

This work focuses on the encapsulation of essential oils into nanometric delivery systems for incorporation into fruit juices, in order to enhance their antimicrobial activity while minimizing the impact on the quality attributes of the final product. A terpenes mixture and d-limonene were encapsulated into nanoemulsions based on food-grade ingredients, prepared by high pressure homogenization at 300 MPa.The effect of the delivery systems on the antimicrobial activity of terpenes was investigated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for three different classes of microorganisms (Lactobacillus delbrueckii, Saccharomyces cerevisiae, Escherichia coli). The increase of the antimicrobial activity resulted to depend on the formulation and mean diameter of the delivery systems as well as on the microorganisms class. Additionally, GC-MS analysis revealed that high intensity processing for nanoemulsion production may affect the chemical stability of several active compounds.The application of the most efficient antimicrobial nanocapsules was tested in pear and orange juices inoculated with L. delbrueckii. Due to the higher antimicrobial activity of the nanoencapsulated compounds, lower antimicrobial concentrations are required for a bactericidal action under accelerated aging at 32 °C, with a minimal alteration of the organoleptic properties of the juice.     

Chemical composition and antimicrobial activity of the essential oils of four Ocimum species growing in Tanzania

As part of ongoing research on Tanzanian plants used as edibles or spices, six samples of essential oils from four Ocimum species (O. basilicum, O. kilimandscharicum, O. lamiifolium, O. suave) were analyzed by GC and GC–MS. Eighty-one compounds, corresponding to 81.1–98.2% of the chemical components of the oils, were identified. Major compounds were either phenyl propane derivatives or terpenoids, including methyl eugenol, 1,8-cineole, camphor, bornyl acetate, germacrene-D, E-myroxide, germacrene-B, caryophylene oxide and p-cymene. The oils were also evaluated for antimicrobial activity against eight bacterial strains and three fungi. The oil of O. suave (B) showed the strongest antibacterial activity; O. suave (A), O. kilimandscharicum and, O. lamiifolium were moderately active, while O. basilicum oil was weakly active. However, none of the oils was active against the fungi species. The study has shown that, Ocimum oils could potentially be used as anti-infective agents.     

Chemical composition and antimicrobial activity of the essential oil of Coriandrum sativum

The essential oil from leaves of Coriandrum sativum L. (Apiaceae), obtained by hydro-distillation was analysed by gas chromatography–mass spectrometry (GC–MS) and also evaluated for in vitro antimicrobial activity. Out of 27 peaks, 24 components, which constitute 92.7%, were identified in the oil. The oil was dominated by aldehydes and alcohols which accounted for 56.1% and 46.3% of the oil, respectively. The major constituents were 2E-decenal (15.9%), decanal (14.3%), 2E-decen-1-ol (14.2%) and n-decanol (13.6%). Other constituents present in fairly good amounts are 2E-tridecen-1-al (6.75%), 2E-dodecenal (6.23%), dodecanal (4.36%), undecanol (3.37%), and undecanal (3.23%). The oil was screened for antimicrobial activity against both Gram positive (Staphylococcus aureus, Bacillus spp.) and Gram negative (Escherichia coli, Salmonella typhi, Klebsiella pneumonia, Proteus mirabilis, Pseudomonas aeruginosae) bacteria and a pathogenic fungus, Candida albicans. The oil showed pronounced antibacterial and antifungal activity against all of the microbes tested, except for P. aeruginosae, which showed resistance.     

Chemical composition and antimicrobial activity of Vitex agnus-castus L. fruits and leaves essential oils

The following study deals with the chemical composition, antimicrobial activity of essential oils of Vitex agnus-castus L. and their main constituents in vitro and in vivo. The main compounds in the oil of unripe fruits were sabinene (17.8%) and 1,8-cineole (17.5%), while in the oil of the ripe fruits dominant compounds were 1,8-cineole (16.3%) and sabinene (13.4%). The leaves oil contained an abundance of 1,8-cineole (22.0%), as well. All of the oils tested were rich sources of α-pinene (12.2%, 9.4% and 9.4%, respectively). Antimicrobial activity was tested using bacterial and fungal strains by the microdilution method. Using the same technique 1,8-cineole and α-pinene showed very high antimicrobial potency as well. As 1,8-cineole was the predominant constituent of the oils, we have chosen to test it further in an in vivo experiment. Randomly chosen apples were treated with 1,8-cineol solution and infected with Aspergillus niger in order to provoke Aspergillus rot in apples. Disease incidence was recorded.     

Antioxidant and antimicrobial activity evaluation and essential oil analysis of Semenovia tragioides Boiss. from Iran

This study reports the essential oil composition, antioxidant and antimicrobial activity of the essential oil and methanol extract of aerial parts of Semenovia tragioides. GC and GC/MS analysis identified 17 compounds representing 99.4% of the oil. The main components comprising 61.9% of the oil were lavandulyl acetate (25.5%), geranyl acetate (12.5%), trans-β-ocimene (8.8%), p-cymene (7.7%) and γ-terpinene (7.4%). The samples were screened for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and β-carotene/linoleic acid assay methods. None of the plant samples showed appreciable antioxidant activity in DPPH test. However, methanol extract exhibited considerable linoleic acid oxidation inhibition (77.4%) in the β-carotene/linoleic acid test, a value near to that of butylated hydroxytoluene (BHT, 95.6%). Total phenolic content of the plant extract as gallic acid equivalents was 7.5 μg/mg. The essential oil exhibited strong antimicrobial activity against all but one of the tested microorganisms while the plant extract only inhibited two of them weakly.     

Chemical composition,antimicrobial, cytotoxic and antioxidant activities of the essential oil of Artemisia indica Willd

Essential oil from the aerial parts of Artemisia indica was analysed by GC-FID and GC–MS. A total of 43 compounds representing 96.8% of the oil were identified and the major components were found to be artemisia ketone (42.1%), germacrene B (8.6%), borneol (6.1%) and cis-chrysanthenyl acetate (4.8%). Antimicrobial activity of the oil was evaluated against seven clinically significant bacterial and two fungal strains. The essential oil and its major constituents exhibited moderate to potent, broad-spectrum antibacterial and antifungal activities targeting both Gram-positive and Gram-negative bacteria. In vitro cytotoxicity evaluation against four human cancer cell lines THP-1 (leukemia), A-549 (lung), HEP-2 (liver) and Caco-2 (colon) showed that the essential oil exhibited concentration dependant growth inhibition in the 10–100 μg/ml dilution range, with IC₅₀ values of 10 μg/ml (THP-1), 25 μg/ml (A-549), 15.5 μg/ml (HEP-2) and 19.5 μg/ml (Caco-2). It was interesting to note that the essential oil also exhibited potent antioxidant activity.     

Chemical composition and antifungal activity of essential oils from three Himalayan Erigeron species

Three Himalayan Erigeron (Asteraceae) species viz Erigeron mucronatus, Erigeron annuus and Erigeron karwinskianus growing in sub-alpine region revealed occurrence of isomeric polyacetylenic constituents viz., matricaria and lachnophyllum esters which accounted for 83.3%, 69.3% and 30.1% of the essential oils from these species, respectively, in addition to mono- and sesquiterpenoids as minor constituents. The antifungal activity tested by poisoned food (PF) techniques against Fusarium oxysporum, Helminthosporium maydis, Rhizoctonia solani, Alternaria solani and Sclerotinia sclerotiorum demonstrated significant inhibition of the mycelial growth of all strains (p < 0.05). The oils (500 μg/mL) showed significant antifungal effect against tested fungi in the growth inhibition range of 37.6–85.5% with respective IC₅₀ values ranging from 88.8 to 660.0 μg/mL as compared to standard fungicides (100% inhibition) with IC₅₀ value in the range of 32.2–129.4 μg/mL. Significant inhibition of spore germination was noticed for F. oxysporum, Curvularia lunata and Albugo candida which were highly susceptible to E. annuus oil with their IC₅₀ values 120.7, 253.5 and 300.4 μg/mL, respectively. Thus, the results obtained in this study demonstrate the potential of essential oils from Himalayan Erigeron species as non-toxic, eco-friendly and biodegradable natural fungicides.     

Screening of the antioxidative and antimicrobial properties of the essential oils of Pimpinella anisetum and Pimpinella flabellifolia from Turkey

The aerial parts of two endemic Pimpinella [Pimpinella anisetum Boiss. & Ball. and Pimpinella flabellifolia (Boiss.) Benth. ex Drude] were hydro-distilled to produce oils in the yields of 2.07% (v/w) and 2.61% (v/w), respectively. The oils were analysed by GC and GC/MS. Twenty-one and nineteen components were identified, representing 99.5% and 99.7% of the oils, respectively. The main compounds of P. anisetum were (E)-anethole (82.8%) and methyl chavicol (14.5%), whereas limonene (47.0%), (E)-anethole (37.9%) and α-pinene (6.0%) were the major constituents of P. flabellifolia. The oils were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. In the first case, P. anisetum oil exerted greater antioxidant activity than that of P. flabellifolia oil with an IC₅₀ value of 5.62 ± 1.34 μg/ml. In the β-carotene/linoleic acid test system, the oil of P. anisetum was superior to P. flabellifolia with 70.5% ± 2.86 inhibition rate. Essential oils of the plants studied here were also screened for their antimicrobial activities against six bacteria and two fungi. The oils showed moderate antimicrobial activity against all microorganisms tested.     

Chemical composition and antimicrobial activity of essential oil of Tarchonanthus camphoratus

The essential oil of Tarchonanthus camphoratus (Asteraceae), obtained by hydro-distillation, was analysed by gas chromatography–mass spectrometry (GC–MS) and also evaluated for antimicrobial activity. Out of 45 peaks representing 99.8% of the oil, 38 components which constitute 95.8% of the total oil were identified. The oil was dominated by monoterpenes, which accounted for 80.9% of the oil. This study indicates the presence of a high percentage of oxygenated monoterpenes (62.3%), of which the main constituents were fenchol (15.9%), 1,8-cineole (14.3%) and α-terpineol (13.2%). Other monoterpenes present in fairly good amounts were α-pinene (6.87%), trans-pinene hydrate (6.51%), terpinen-4-ol (4.74%) and camphene (3.76%). The oil was screened for antimicrobial activity against both Gram positive (Staphylococcus aureus, Bacillus ssp.) and Gram negative (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Klebsiella pneumoniae, Proteus mirabilis) bacteria and a pathogenic fungus Candida albicans. Except for P. aeruginosa, which showed resistance, the oil had pronounced antibacterial and antifungal activities.     

Chemical composition and antimicrobial activity of the essential oil of Amomum tsao‐ko

BACKGROUND: The chemical composition of the essential oil obtained by hydrodistillation from the dried fruits of Amomum tsao‐ko was analysed by gas chromatography/mass spectroscopy (GC/MS). The antimicrobial activity of the oil was evaluated against 16 micro‐organisms using agar disc diffusion and broth microdilution methods. RESULTS: Seventy‐three compounds, constituting about 97.56% of the total oil, were identified. The main components were 1,8‐cineole (45.24%), ρ‐propylbenzaldehyde (6.04%), geraniol (5.11%), geranial (4.52%), α‐terpineol (3.59%) and α‐phellandrene (3.07%). The essential oil showed a broad spectrum of antimicrobial activity against all the tested micro‐organisms, including Gram‐positive and Gram‐negative bacteria, and fungi. The oil exerted the strongest bactericidal activity against Staphylococcus aureus CCTCC AB91118, with minimum inhibitory and bactericidal concentrations of 0.20 g L^?1. CONCLUSION: Our study suggests that the Amomum tsao‐ko essential oil could be one of new medicinal resources for antibacterial and antifungal agents. Copyright © 2008 Society of Chemical Industry     

Composition,cytotoxicity and antimicrobial activity of essential oil from Dictamnus dasycarpus

The composition of the essential oil from Dictamnus dasycarpus was analysed by GC–MS; 47 constituents (88.9% of the total oil) were identified. The main compounds were syn-7-hydroxy-7-anisylnorbornene (29.4%), pregeijerene (15.5%) and geijerene (11.4%). The antimicrobial activity of the essential oil was evaluated against nine microorganisms using disc diffusion and broth microdilution methods. The oil showed the strongest bactericidal activity against Staphylococcus aureus ATCC 25923 and methicillin-resistant S. aureus. The in vitro cytotoxicity of the oil on six human cancer cell lines was also examined. The cytotoxicity of the oil on three human breast cancer cell lines was significantly stronger than on other cell lines.     

Chemical composition and antimicrobial activity of the essential oil of Lippia grandis Schauer (Verbenaceae) from the western Amazon

Lippia grandis Schauer is an aromatic plant that has been used as a spice in Brazilian culinary and in traditional medicine to treat liver disease, disorders of the stomach and throat infections. We determined the chemical composition of the essential oil of L. grandis and evaluated its potential for the treatment of clinically-important pathogenic micro-organisms. The essential oil was obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry (GC-MS), giving carvacrol (37.12%), ρ-cymene (11.64%), and thymol (7.83%) as the main components. The agar disk diffusion method of the essential oil was effective against 75% of the micro-organisms analyzed, in particular, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. The minimum inhibitory concentration was 0.57 mg/ml for E. faecalis and 1.15 mg/ml for all the other strains. The results indicate that the essential oil of L. grandis contains chemical compounds with good potential for the treatment of infections.     

Antioxidant,anticholinesterase and antimicrobial constituents from the essential oil and ethanol extract of Salvia potentillifolia

The essential oil of Salvia potentillifolia was analysed by GC and GC–MS. Totally, 123 components were detected in both hydrodistilled and steam-distilled oils, α- and β-pinenes being major compounds. The antioxidant activities were determined by using complementary tests, namely, DPPH radical-scavenging, β-carotene-linoleic acid and reducing power assays. The ethanol extract also showed better activity (IC₅₀ = 69.4 ± 0.99 μg/ml) than that of BHT in the DPPH system, and showed great lipid peroxidation inhibition in the β-carotene-linoleic acid system (IC₅₀ = 30.4 ± 0.50 μg/ml). The essential oil showed meaningful butyrylcholinesterase activity (65.7 ± 0.21%), and α-pinene showed high acetylcholinesterase inhibitory activity (IC₅₀ = 86.2 ± 0.96 μM) while β-pinene was inactive. Antimicrobial activity was also investigated on several microorganisms, and the essential oil showed high activity against Bacillus subtilis and B. cereus. It also exhibited remarkable anticandidal activity against Candida albicans and C. tropicalis with MIC values of 18.5 and 15.5 μg/ml, respectively, while α- and β-pinenes showed moderate activity.