Composition and Antimicrobial Activity of <Emphasis Type="Italic">Helichrysum italicum</Emphasis> Essential Oil and Its Terpene and Terpenoid Fractions

The essential oil of Helichrysum italicum (Roth) G. Don from Croatia has been fractionated into terpene and terpenoid fractions and analyzed using GC/MS. Fifty-two compounds were identified. The main hydrocarbons of the oil were α-pinene (10.2%), α-cedrene (9.6%) aromadendrene (4.4%), β-caryophyllene (4.2%), and limonene (3.8%), while the main oxygen-containing compounds were neryl acetate (11.5%), 2-methylcyclohexyl pentanoate (8.3%), 2-methylcyclohexyl octanoate (4.8%), and geranyl acetate (4.7%). The essential oil and its terpene and terpenoid fractions were evaluated for antibacterial and antifungal activities. The screening of antimicrobial activity was conducted by a disc diffusion test and the minimum inhibitory concentration was determined against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. The essential oil and its terpenoid fraction exhibited higher antimicrobial activity with respect to the terpene fraction. The antimicrobial activities of the oil and its terpenoid fraction were more pronounced against Staphylococcus aureus and Candida albicans.__________Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 29–32, January–February, 2005.     

Investigation of the chemical composition–antibacterial activity relationship of essential oils by chemometric methods

The antibacterial effects of Thymus vulgaris (Lamiaceae), Lavandula angustifolia (Lamiaceae), and Calamintha nepeta (Lamiaceae) Savi subsp. nepeta var. subisodonda (Borb.) Hayek essential oils on five different bacteria were estimated. Laboratory control strain and clinical isolates from different pathogenic media were researched by broth microdilution method, with an emphasis on a chemical composition–antibacterial activity relationship. The main constituents of thyme oil were thymol (59.95%) and p-cymene (18.34%). Linalool acetate (38.23%) and β-linalool (35.01%) were main compounds in lavender oil. C. nepeta essential oil was characterized by a high percentage of piperitone oxide (59.07%) and limonene (9.05%). Essential oils have been found to have antimicrobial activity against all tested microorganisms. Classification and comparison of essential oils on the basis of their chemical composition and antibacterial activity were made by utilization of appropriate chemometric methods. The chemical principal component analysis (PCA) and hierachical cluster analysis (HCA) separated essential oils into two groups and two sub-groups. Thyme essential oil forms separate chemical HCA group and exhibits highest antibacterial activity, similar to tetracycline. Essential oils of lavender and C. nepeta in the same chemical HCA group were classified in different groups, within antibacterial PCA and HCA analyses. Lavender oil exhibits higher antibacterial ability in comparison with C. nepeta essential oil, probably based on the concept of synergistic activity of essential oil components.     

Composition and antimicrobial activity of the essential oil from the branches of Jacaranda cuspidifolia Mart. growing in Sichuan,China

This study represents the first report on the chemical composition and antimicrobial activity of the essential oil from the branches of Jacaranda cuspidifolia Mart. Thirty-three compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS) and the major constituents of the essential oil were Palmitic acid (31.36%), (Z) ? 9,17-Octadecadienal (12.06%), Ethyl palmitate (3.81%), Perhydrofarnesyl acetone (2.07%), γ-Maaliene (1.88%), and Cedro (1.42%) and 9,12-Octadecadienoic acid ethyl ester (1.42%). The in vitro antimicrobial activities of the essential oil were evaluated by the disc diffusion method, and the inhibition zones against Escherichia coli, Staphylococcus aureus and Candida albicans were 7.10, 8.20 and 7.25 mm, respectively. The oil showed moderate activities against E. coli, S. aureus and C. albicans with minimum inhibition concentration (MIC) values of 17.3 mg/mL, 12.9 mg/mL and 16.0 mg/mL, respectively.     

Chromatographic analysis,antimicrobial and insecticidal activities of the essential oil of Phlomis floccosa D. Don.

The present study was conducted to investigate for the first time the chemical composition and insecticidal and antimicrobial properties of Phlomis floccosa D. Don. essential oil isolated by hydro‐distillation of its aerial parts. Qualitative and quantitative analyses of the essential oil on the basis of gas chromatography and mass spectrometry (GC/FID and GC/MS) revealed the presence of 59 organic volatiles representing 86.9% of the total constituents. The major compounds were germacrene‐D (19.7%) followed by β‐caryophyllene (15.5%), caryophyllene oxide (8.3%), hexadecenoic acid (7.9%) and carvacrol (6.1%). The broth microdilution method was conducted to test the antimicrobial activity of the essential oil against five pathogens: Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, Bacillus subtilis and the yeast Candida albicans. The oil of P. floccosa D. Don. shows promising activity against the Gram‐positive bacteria S. aureus and B. subtilis and the yeast C. albicans (minimum inhibitory concentration = 625 μg.mL^?1). The effectiveness of the essential oil was assessed on both Tribolium confusum and Sitophilus zeamais pest insects and it was more pronounced against T. confusum, showing a moderate mortality of 47.5%.     

Phytochemistry,antioxidant and antibacterial activities of two Moroccan Teucrium polium L. subspecies: Preventive approach against nosocomial infections

The aim of the present study was to determine the chemical composition and antioxidant activity of essential oils (EOs) from two Teucrium polium subspecies, to evaluate, also their antibacterial activities, against some nosocomial-bacteria. The phytochemical screening of essential oils was analyzed using gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry analysis (GC-MS). The antibacterial activities were assessed by disc diffusion method and minimal inhibitory concentration (MIC), against Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Citrobacter koseri and Acinetobacter baumannii) and Gram-positive bacteria Staphylococcus aureus. The antioxidant potential was evaluated in vitro by three assays, namely free radical scavenging activity against 1,1-diphenyl-2-picrylhydrzyl (DPPH), ferric reducing activity power (FRAP) and total antioxidant capacity. Twenty-six components were identified in the EO of Teucrium polium subsp. aurum representing. Its major component was Caryophyllene (19.13%) followed by γ-Muurolene (13.02%), τ-cadinol, (11.01%), α-Gurjunene (9.2%), Rosifoliol (8.79%), 3-Carene (7.04%). However, twenty two components were identified in the EO of T. polium subsp. polium. Its major components are 3-carene (16.49%), γ-Muurolene (14.03%), α-pinene (9.94%), α-phellandrene (6.93%) and Caryophyllene (7.51%). The antibacterial activity of both essential oils showed a higher activity against tested nosocomial bacteria especially against S. aureus and A. baumannii. The EO of T. polium subsp. aureum showed better antioxidant activity as measured by DPPH and FRAP assays with IC₅₀ values of 3.7 ± 0.2 mg/ml and 2.31 ± 0.11 mg/ml, respectively. The total antioxidant capacity assay showed that T. polium subsp. aureum had a significant activity with value to 3308.27 mg equivalent to ascorbic acid/g of EO. The Moroccan T. polium essential oils could be exploited as an antimicrobial agent for the treatment of several infectious diseases caused by bacteria, especially, those who have developed resistance to conventional antibiotics.     

Chemical Composition Analysis and Antimicrobial Screening of the Essential Oil of a Rare Plant from Jordan: Ducrosia flabellifolia

The composition of the essential oil isolated from the fresh and dry leaves of Ducrosia flabellifolia Boiss. (Apiaceae) was determined by gas chromatography and gas chromatography–mass spectrometry using hydrodistillation and solid phase microextraction (SPME). The hydrodistilled oil of the fresh leaves yielded 38 components, accounting for 98.67% of the total oil content, while thirty components were detected from the fresh leaves by solid phase microextraction (94.85%). Fifty-one and 36 components were identified in the hydrodistilled and SPME oils of the dried leaves amounting to 98.78% and 94.52%, respectively. A total of 25 components accounting for 97.24% of the total composition were characterized in the SPME oil of the fresh flowers. Aliphatic compounds predominated in the volatile fractions of the leaves and flowers of both methods with n-decanol, n-decanal, and dodecanal as the main constituents. The α- and ß-pinene were the major monoterpenoids in the oils. The hydrodistilled oil was screened for its antimicrobial and antioxidant activities. The minimal inhibitory concentration of the volatile oil was determined using a microdilution method in 96 well plates against a panel of gram (+), gram (?) bacteria, and fungi. Overnight cultures of reference strains of Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus were used as test microorganisms. The oil exhibited the best activity against C. albicans (MIC 234 µg/mL) and S. aureus (MIC 234 µg/mL) whereas weak activity was detected against E. coli and P. aeruginosa. No antioxidant activity could be detected.     

Chemical composition of essential oils from different parts of Protium heptaphyllum (Aubl.) Marchand and their in vitro antibacterial activity

Abstract

In Brazilian folk medicine, Protium heptaphyllum is used to treat inflammatory conditions and to hasten wound repair. This paper aims to investigate the chemical composition and the in vitro antibacterial effects of the essential oils (EOs) obtained from P. heptaphyllum leaves and ripe and unripe fruits against a representative panel of oral pathogens. The GC-FID and GC-MS analysis revealed that the major components determined in P. heptaphyllum essential oils were myrcene (59.0%), β-elemene (17.2%), limonene (12.9%), spathulenol (12.6%), α-cubebene (11.6%), germacrene D (10.6%), trans-nerolidol (9.8%), and α-cadinol (8.8%). The essential oils of the ripe and unripe fruits showed the strongest antibacterial activity against the anaerobic bacteria Prevotella nigrescens (MIC?=?50?µg/mL). The leaf essential oil displayed very promising activity against Streptococcus mutans (MIC?=?50?µg/mL) and Streptococcus mitis (MIC?=?62.5?µg/mL). The antibacterial activity of EOs against oral pathogens is also described for the first time.

     

Chemical composition and antimicrobial activities of Perovskia artemisioides Boiss. essential oil

The Perovskia artemisioides Boiss. essential oil obtained by hydrodistillation method of flowers growing wild in the north of Iran. The study led to the identification of 29 compositions by a combination of HP-5 GC–FID and GC–MS analytical techniques. The constituents were identified in P. artemisioides essential oil with 1,8-cineole (29.9%), camphor (29.5%) and α-pinene (7.8%) as main constituents as well as δ-3-carene (5.1%), camphene (3.3%) and β-pinene (2.7%). The oil was identified by a much larger amount of monoterpenes (87.7%) and sesquiterpenes (6.3%). The results of antimicrobial activity exhibit that the extracted essential oil has presented a high inhibiting activity against five microbial strains up to 18 mm. Also, the MIC and MBC results displayed that Staphylococcus aureus, Escherichia coli and Salmonella typhi were inhibited by P. artemisioides essential oil. Therefore, determination of essential oils in this research showed a relatively similar pattern to those published for the other species of Perovskia.     

Evaluation of seasonal chemical composition,antibacterial, antioxidant and anticholinesterase activity of essential oil from Eugenia brasiliensis Lam.

This study describes the seasonal composition and the antibacterial, antioxidant and anticholinesterase activity of the essential oil from Eugenia brasiliensis leaves. Analysis by using GC allowed the identification of 40 compounds. It was observed that the monoterpenes varied more (42%) than the sesquiterpenes (14%), and that the monoterpene hydrocarbons suffered the greatest variation throughout the year (64%). Major compounds were spathulenol in the spring (16.02 ± 0.44%) and summer (18.17 ± 0.41%), τ-cadinol in the autumn (12.83 ± 0.03%) and α-pinene (15.94 ± 0.58%) in the winter. Essential oils were tested for their antibacterial activity, and the best result was obtained from the autumn oil, with MIC = 500 μg mL^? 1 against Staphylococcus saprophyticus and Pseudomonas aeruginosa. Antioxidant activity was evaluated using DPPH, lipid peroxidation and iron-reducing power assays, as well as the anticholinesterase activity. Both tests showed a weak performance of the essential oils.     

Determination of the chemical composition and antioxidant,anticancer, and antibacterial properties of essential oil of Pulicaria crispa from Saudi Arabia

Essential oils obtained from plants play critical roles in food and medicine. In this study, the phytochemical composition of Pulicaria crispa essential oil, and its antibacterial, antioxidant and anticancer properties were determined in vitro. The essential oil was extracted from the aerial parts of P. crispa through hydro-distillation using a Clevenger-type apparatus, and it was analyzed with GC-MS. The most dominant chemical constituents of the essential oil were sesquiterpenes (78.26%). The higher constituents were β-caryophyllene oxide (33.97%), modephene (23.34%), geranyl propionate (6.32%), geranyl isovalerate (6.74%), 4-cadinadiene (5%), humulene (4.05%), and β-caryophyllene (2.73%). The essential oil exhibited DPPH radical activity, and it exerted antibacterial effect against gram positive bacteria (Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. However, it had no antibacterial effect on gram negative bacteria (Pseudomonas aeruginosa, Shigella sonnei, Klebsiella pneumoniae and Escherichia coli). The P. crispa essential oil produced significant cytotoxic effects against Hep-G2, MCF-7, Coca-2, and HT-29 ?cells. The oil was most toxic to Hep-G2 cells, based on its IC₂₀ and IC₅₀ values. These results indicate that the essential oil from P. crispa has potent biological properties which can be useful in the food and pharmaceutical industries.     

Chemical Composition and Biological Activities of Essential Oils from the Leaves,Stems, and Roots of Kadsura coccinea

The chemical composition and biological activities of the essential oils from the leaves, stems, and roots of Kadsura coccinea (K. coccinea) were investigated. The essential oils were extracted by hydro distillation and analyzed by gas chromatography mass spectrometry (GC-MS) and gas chromatography with flame ionization detector (GC-FID). Antioxidant activities of the essential oils were examined with DPPH radical scavenging assay, ABTS cation radical scavenging assay, and ferric reducing antioxidant power assay. Antimicrobial activities were evaluated by determining minimum inhibitory concentrations (MIC) and minimum microbiocidal concentrations (MMC). Acetylcholinesterase and butyrylcholinesterase inhibitory activity of the essential oils were also tested. A total of 46, 44, and 47 components were identified in the leaf, stem, and root oils, representing 95.66%, 97.35%, and 92.72% of total composition, respectively. The major compounds of three essential oils were α-pinene (16.60–42.02%), β-pinene (10.03–18.82%), camphene (1.56–10.95%), borneol (0.50–7.71%), δ-cadinene (1.52–7.06%), and β-elemene (1.86–4.45%). The essential oils were found to have weak antioxidant activities and cholinesterase inhibition activities. The essential oils showed more inhibitory effects against Staphylococcus aureus (S. aureus) than those of other strains. The highest antimicrobial activity was observed in the root oil against S. aureus, with MIC of 0.78 mg/mL. Therefore, K. coccinea essential oils might be considered as a natural antibacterial agent against S. aureus with potential application in food and pharmaceutical industries.     

Gas chromatographic–mass spectrometric analysis of volatiles obtained by four different techniques from Salvia rosifolia Sm., and evaluation for biological activity

Four different isolation techniques, conventional hydrodistillation (HD), microwave-assisted hydrodistillation (MWHD), microdistillation (MD) and micro-steam distillation-solid-phase microextraction (MSD-SPME), have been used to analyze the volatile constituents from the aerial parts of Salvia rosifolia Sm. by gas chromatography and gas chromatography coupled to mass spectrometry. HD and MWHD techniques produced quantitatively (yield, 0.39% and 0.40%) and qualitatively (aromatic profile) similar essential oils. α-Pinene (15.7–34.8%), 1,8-cineole (16.6–25.1%), β-pinene (6.7–13.5%), β-caryophyllene (1.4–5.0%) and caryophyllene oxide (1.4–4.4%) were identified as major constituents of this Turkish endemic species. Besides, the hydrodistilled oil of S. rosifolia was evaluated for antibacterial, antifungal, anticancer, antioxidant and cytotoxic activities. The hydrodistilled oil of S. rosifolia showed antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA) with a MIC value of 125 μg/mL. Other human pathogenic microorganisms (Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Salmonella typhimurium, Staphylococcus epidermidis, Candida albicans) were also inhibited within a moderate range (MIC = 125–1000 μg/mL). Antifungal activity of the oil was also observed against the strawberry anthracnose-causing fungal plant pathogens Colletotrichum acutatum, C. fragariae and C. gloeosporioides. No cytotoxicity was observed for S. rosifolia oil up to 25 mg/mL against malignant melanoma, epidermal, ductal and ovary carcinoma.     

Chemical composition and antimicrobial activity of the essential oils of Onychopetalum amazonicum R.E.Fr.

The essential oils from leaves, twigs and trunk bark of Onychopetalum amazonicum R.E. Fr. (Annonaceae), obtained by hydrodistillation, were analysed by GC and GC–MS, and also were evaluated for in vitro antimicrobial activity. Forty-one compounds, which correspond to 75.0–92.2% of the oil components, were identified. Major compounds were sesquiterpenes, including (E)-caryophyllene, caryophyllene oxide, spathulenol, α-gurjunene, allo-aromadendrene and α-epi-cadinol. The oils were evaluated for antimicrobial activities against four bacteria strains and five pathogenic fungi. The oil of the trunk bark exhibited good activity against Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 10538 and Kocuria rhizophila ATCC 9341, with a minimal inhibitory concentration of 62.5 μg/mL. The essential oil composition and the antimicrobial evaluation are reported for the first time for the genus Onychopetalum.     

Chemical Composition and Synergistic Potential of Mentha pulegium L. and Artemisia herba alba Asso. Essential Oils and Antibiotic against Multi-Drug Resistant Bacteria

The essential oils were obtained by hydrodistillation from aerial parts of Mentha pulegium L. (M. pulegium L.) and Artemisia herba alba (A. herba alba) Asso. and analyzed by gas chromatography–flame ionization detector chromatograpy (GC–FID) and gaz chromatography–mass spectrometry (GC–MS). The antibacterial activities of the oils were determined by the disk diffusion method and a microdilution broth assay against six bacteria stains. The combinations of these essential oils with antibiotics were evaluated against two multi-drug-resistant bacteria strains: imipenem-resistant Acinetobacter baumannii (IRAB S3310) and methicillin-resistant Staphylococcus aureus (MRSA S19). The chemical analysis of M. pulegium essential oil revealed the presence of pulegone (74.8%) and neoisomenthol (10.0%). A. herba alba essential oil was characterized by camphor (32.0%), α-thujone (13.7%), 1,8-cineole (9.8%), β-thujone (5.0%), bornéol (3.8%), camphene (3.6%), and p-cymene (2.1%). All strains tested except Pseudomonas aeruginosa were susceptible to these oils. The combinations of essential oils with antibiotics exerted synergism, antagonism, or indifferent effects. The best effect was observed with A. herba alba essential oil in association with cefoxitin (CX) against MRSA S19. However, for IRAB S3310, the strongest synergistic effect was observed with M. pulegium in association with amikacin (AK). This study demonstrated that M. pulegium and A. herba alba essential oils have antibacterial activities which could be potentiated by antibiotics especially in the case of IRAB S3310.     

Chemical composition and antibacterial activity of the essential oil from Agathis dammara (Lamb.) Rich fresh leaves

The essential oil of fresh leaves from Agathis dammara (Lamb.) Rich was extracted using hydro-distillation, and GC-FID and GC–MS were used to analyse the essential oil. Nineteen compounds were identified, among which the major components were limonene (36.81%), β-bisabolene (33.43%) and β-myrcene (25.48%). In the antibacterial test, disc diffusion method and micro-well dilution assay proved that the essential oil had significant antibacterial activities. The inhibition zones against Staphylococcus aureus and Pseudomonas aeruginosa were 23.7 and 23 mm, respectively, which demonstrated that the inhibition effects were greater than positive control (10 μg/disc streptomycin). And the lowest MIC value of the essential oil was found against S. aureus (1.25 mg/mL) and Bacillus subtilis (1.25 mg/mL). This is the first report on the antibacterial activities of A. dammara essential oil.     

Chemical composition and biological evaluation of the volatile constituents from the aerial parts of Nephrolepis exaltata (L.) and Nephrolepis cordifolia (L.) C. Presl grown in Egypt

The essential oil from the aerial parts of Nephrolepis exaltata and Nephrolepis cordifolia obtained by hydro-distillation were analyzed by gas chromatography/ mass spectrometry. The essential oils exhibited potential antibacterial and antifungal activities against a majority of the selected microorganisms. NEA oil showed promising cytotoxicity in breast, colon and lung carcinoma cells. The results presented indicate that NEA oil could be useful alternative for the treatment of dermatophytosis.

Comparative investigation of hydro-distilled volatile constituents from aerial parts (A) of Nephrolepis exaltata (NE) and Nephrolepis cordifolia (NC) (Family Nephrolepidaceae) was carried out. Gas chromatography/mass spectrometry revealed that oils differ in composition and percentages of components. Oxygenated compounds were dominant in NEA and NCA. 2,4-Hexadien-1-ol (16.1%), nonanal (14.4%), β-Ionone (6.7%) and thymol (2.7%) were predominant in NEA. β-Ionone (8.0%), eugenol (7.2%) and anethol (4.6%) were the main constituents in NCA. Volatile samples were screened for their antibacterial and antifungal activities using agar diffusion method and minimum inhibitory concentrations. The cytotoxic activity was evaluated using viability assay in breast (MCF-7), colon (HCT-116) and lung carcinoma (A-549) cells by the MTT assay. The results revealed that NEA oil exhibited potential antimicrobial activity against most of the tested organisms and showed promising cytotoxicity.     

Chemical composition and biological activities of Iranian Achillea wilhelmsii L. essential oil: a high effectiveness against Candida spp. and Escherichia strains

In the case of Achillea wilhelmsii, 30 compounds were identified representing 94.48% of the total oil with a yield of 0.82% w/w. The major constituents of the oil were described as α-thujene (6.11%), α-pinene (5.11%), sabinene (5.23%), p-cymene (7%), 1,8-cineole (6%), linalool (10%), camphor (8.43%), thymol (18.98%) and carvacrol (20.13%). A. wilhelmsii oil exhibited higher antibacterial and antifungal activities with a high effectiveness against Escherichia coli and Candida albicans with the lowest minimum inhibitory concentration and minimum bactericidal concentration/minimum fungicidal concentration value (2 ± 0.0–2 ± 0.0 g/mL, 1 ± 0.5–1 ± 0.5 g/mL), respectively. Results showed that A. wilhelmsii oil exhibits a higher activity in each antioxidant system with a special attention for β-carotene bleaching test (IC₅₀: 19 μg/mL) and reducing power (EC₅₀: 10 μg/mL). Antioxidant activity-guided fractionation of the oil was carried out by TLC-bioautography screening and fractionation resulted in the separation of main antioxidant compounds which were identified as thymol (65%) and carvacrol (19%). In conclusion, these results support the use of the essential oil and its main compounds for their antioxidant properties and antimicrobial activity.     

Chemical Composition and Biological Activities of the Essential Oils from <em>Duguetia lanceolata</em> St. Hil. Barks

Essential oils of Duguetia lanceolata barks, obtained at 2 (T2) and 4 h (T4), were identified by gas chromatography and gas chromatography/mass spectrometry. β-Elemene (12.7 and 14.9%), caryophyllene oxide (12.4 and 10.7%) and β-selinene (8.4 and 10.4%) were the most abundant components in T2 and T4, respectively. The essential oils inhibited the growth of Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Candida albicans. The essential oils were cytotoxic against brine shrimp. The extraction time influenced the chemical composition and biological activities of essential oils obtained from the barks of D. lanceolata.     

Chemical composition and evaluation of the antimicrobial activity of the essential oil from leaves of Eugenia platysema

This study describes the qualitative and quantitative chemical composition and evaluates the antibacterial activity of essential oil from Eugenia platysema leaves. Analysis by GC–FID and GC–MS allowed the identification of 22 compounds. Different from the other species of the Eugenia genus, the major compound found in the essential oil was the diterpene phytol (66.05%), being this the first report of the presence of this compound in the essential oils from Eugenia genus. The sesquiterpene elixene was the second most concentrated compound in the studied essential oil (9.16%). The essential oil from E. platysema was tested for its antibacterial activity against cell-walled bacteria and mollicute strains of clinical interest using the microdilution broth assay. The results showed that the essential oil of E. platysema was inactive until 1000 μg mL^?1 against tested bacteria.     

Chemical composition and antibacterial activity of methanolic extract and essential oil of Iranian Teucrium polium against some of phytobacteria

The antibacterial activity of essential oil and methanolic extract of Teucrium polium was determined against Pseudomonas aeruginosa, Pantoea agglomerans, Brenneria nigrifluens, Rhizobium radiobacter, Rhizobium vitis, Streptomyces scabies, Ralstonia solanacearum, Xanthomonas campestris and Pectobacterium cartovorum by disc diffusion method. Minimum inhibitory concentration and minimum bactericidal concentration were determined by using the serial dilution method. Chemical composition of essential oil and methanolic extract was determined by GC-MS and HPLC. α-Pinene (25.769%) and myrcene (12.507) were of the highest percentage in T. polium essential oil, and sinapic acid (15.553 mg/g) and eugenol (6.805 mg/g) were the major compounds in the methanolic extract. Our results indicate that both methanolic extract and essential oil did not show antibacterial activity against P. aeruginosa. Also the essential oil did not show antibacterial activity against P. cartovorum. In general, both methanolic extract and essential oil showed the same antibacterial activity against R. solanacearum, P. agglomerans, B. nigrifluens and S. scabies.