Antibacterial activity and chemical composition of the essential oil of Grammosciadium platycarpum Boiss. from Iran

The chemical composition of the essential oils obtained from two samples (GP1 and GP2) of Grammosciadium platycarpum Boiss. was analyzed by GC and GC-MS. The analysis of the oils resulted in the identification of twenty-two constituents. Linalool (79.0%-GP1, 81.8%-GP2) and limonene (10.0%, 5.8%) were found to be the major components, respectively. The in vitro antibacterial activities of these oils and their main compounds against seven Gram-positive and Gram-negative bacteria were investigated. The results exhibited that the total oils and their major components possess strong to moderate activities against all the tested bacteria except for Pseudomonas aeruginosa.     

Composition and antimicrobial activity of the essential oil of Dicyclophora persica Boiss. from Iran

The chemical composition of the essential oil of Dicyclophora persica Boiss. was identified by GC and GC-MS analysis. The analysis of the oil resulted in the identification of forty-five components constituting 98.6% of the total oil. The main constituents were a-pinene (31.5%), (Z)-beta-ocimene (23.3%), p-cymene (6.7%) and (E)-beta-ocimene (5.4%). The antimicrobial activity of the oil was tested by the disk diffusion method against four Gram-positive (Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) bacteria together with a fungus (Aspergillus niger). The oil showed strong inhibition activity toward all the tested microorganisms except for Pseudomonas aeruginosa.     

Antibacterial activity and composition of the essential oil of Ziziphora clinopodioides subsp. bungeana (Juz.) Rech. f. from Iran

The chemical composition of the essential oil obtained from the aerial flowering parts of Ziziphora clinopodioides subsp. bungeana (Juz.) Rech. f. was analyzed by GC and GC-MS. Thirty-two components representing 97.1% of the total oil were identified. Oxygenated monoterpenes (94.3%) were the predominant fraction of the oil with pulegone (65.2%), isomenthone (11.9%), 1,8-cineole (7.8%) and piperitenone (6.5%) as the main constituents. Antibacterial activity of the oil and also its two main components (pulegone and 1,8-cineole) were tested against seven bacteria. It was found that the oil exhibited interesting antibacterial activity against Staphylococcus epidermidis, S. aureus, Escherichia coli and Bacillus subtilis with MIC values of 3.75 mg/ml.     

Antimicrobial activity and composition of the essential oil of Gontscharovia popovii from Iran

The aerial parts of Gontscharovia popovii (B. Fedtsch. and Gontsch.) Boriss. were collected at full flowering stage. The essential oil was isolated by hydrodistillation and analyzed by a combination of capillary GC and GC-MS. Thirty-one components were identified with the main constituent being carvacrol (71.9%), followed by linalool (5.5%), p-cymene (4.5%) and gamma-terpinene (4.4%). The in vitro antimicrobial activity of the essential oil of G. popovii was studied against seven Gram-positive and Gram-negative bacteria (Bacillus subtilis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and three fungi (Candida albicans, Saccharomyces cerevisiae and Aspergillus niger). The results of the bioassays showed that the oil exhibited strong antimicrobial activity against all the tested fungi and bacteria except for the resistant bacterium Pseudomonas aeruginosa.     

Antimicrobial activity and chemical composition of the essential oil of Nepeta crispa Willd. from Iran

The composition and antimicrobial activity of the essential oil of Nepeta crispa Willd., an endemic species from Iran, was studied. The oil was obtained from the aerial parts of the plant and analyzed by GC and GC/MS. Twenty-three compounds, accounting for 99.8% of the total oil, were identified. The main constituents were 1,8-cineol (47.9%) and 4aalpha,7alpha,7abetanepetalactone (20.3%). The antimicrobial activity of essential oil of N. crispa was tested against seven gram-negative or gram-positive bacteria and four fungi. The results of the bioassays showed the interesting antimicrobial activity, in which the gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, were the most sensitive to the oil. Also, the oil exhibited a remarkable antifungal activity against all the tested fungi.     

Antimicrobial activity, essential oil composition and micromorphology of trichomes of Satureja laxiflora C. Koch from Iran

The antimicrobial activity, essential oil composition and micromorphology of trichomes of Satureja laxiflora C. Koch, a native plant from Iran, were studied. The essential oil was obtained from the aerial parts at the flowering stage by hydrodistillation, and analyzed by GC and GC/MS. Thirty-three compounds representing 99.1% of the total oil were characterized. The major compounds were thymol (63.9%) and gamma-terpinene (11.9%) followed by carvacrol (4.8%), p-cymene (3.9%), geraniol (3.2%) and geranyl acetate (3.1%). Furthermore, the essential oil and its three main components were tested against two bacteria and three fungi. The result of the bioassays has been shown that the oil possesses potent antimicrobial property. Chemical studies confirmed that a major portion of this antimicrobial activity is due to thymol present in the oil. Micromorphological analysis by SEM of both vegetative and reproductive organs revealed the presence of abundant sessile capitate and sparse short-stalked glandular trichomes along with retrorse eglandular hairs, giving useful diagnostic characters for identification of this medicinal plant.     

Antibacterial activity of Ocimum gratissimum L. essential oil.

The essential oil (EO) of Ocimum gratissimum inhibited Staphylococcus aureus at a concentration of 0.75 mg/ml. The minimal inhibitory concentrations (MICs) for Shigella flexineri, Salmonella enteritidis, Escherichia coli, Klebsiella sp., and Proteus mirabilis were at concentrations ranging from 3 to 12 microg/ml. The endpoint was not reached for Pseudomonas aeruginosa (>=24 mg/ml). The MICs of the reference drugs used in this study were similar to those presented in other reports. The minimum bactericidal concentration of EO was within a twofold dilution of the MIC for this organism. The compound that showed antibacterial activity in the EO of O. gratissimum was identified as eugenol and structural findings were further supported by gas chromatography/mass spectra retention time data. The structure was supported by spectroscopic methods.     

Chemical composition and biological activity of the essential oils of Senecio aegyptius var. discoideus Boiss

The essential oil of Senecio aegyptius var. discoideus flowers, leaves, stems and roots were isolated by hydrodistillation. Analysis of the oils by capillary GLC and GLC-mass spectrometry were performed and 34 out of 37 compounds were identified. The main component was isolated and characterized as 1,10-epoxyfuranoeremophilane using a combination of GLC, GLC-MS, and NMR analyses. The oils of flowers, leaves and stems were rich in monoterpene hydrocarbons while the root oil mainly contains furanoeremophilanes. Flower and leaf volatile oils showed significant level of antifungal activity against C. albicans, moderate effect against Gram positive bacteria, however, it has weak activity against Gram negative bacteria. The isolated sesquiterpene (1,10-epoxyfuranoeremophilane) exhibited substantial inhibitory activity against Gram negative bacteria.     

Chemical composition and antibacterial activity of essential oil from Artemisia feddei

The chemical components of the essential oil from Artemisia feddei LEV. et VNT. were analyzed using GC-MS. Ninety-nine compounds, accounting for 96.23% of the extracted essential oil, were identified. The main oil compounds were 1,8-cineole (16.86%), chamazulene (9.04%), alpha-terpineol (8.18%), alpha-phellandrene (5.78%), alpha-thujone (5.51%), alpha-terpinyl acetate (5.07%), borneol (5.08%), beta- caryophyllene (4.71%), camphor (4.04%), and terpinen-4-ol (3.04%). The antimicrobial activity of the essential oil and some of its compounds was tested against 15 different genera of oral bacteria. The essential oil from A. feddei had a considerable inhibitory effect on all the obligate anaerobic bacteria tested (MICs, 0.025 to 0.05 mg/ml; MBCs, 0.025 to 0.1mg/ml), whereas the major compounds demonstrated different degrees of growth inhibition.     

Chemical composition and antimicrobial activity of Satureja hortensis L. essential oil

Essential oil of Satureja hortensis L. was analyzed by GC and GC/MS and tested by a broth micro-well dilution method for activity against multiresistant clinical isolates of pathogenic bacteria from 10 different genera: Klebsiella, Escherichia, Proteus, Staphylococcus, Streptococcus, Pseudomonas, Enterococcus, Enterobacter, Citrobacter and Acinetobacter. The main compounds in the oil were carvacrol (67%), γ-terpinene (15.3%) and p-cymene (6.73%). The oil showed activity against all tested strains. MIC/MBC values were in the range of 0.78-25 μl/ml, with the exception of the strain P. aeruginosa. Microbicidal concentration for this particular strain (50 μl/ml) was the highest tested concentration. The oil showed inhibitory and bactericidal effect at the same concentration (MIC=MBC) for all but three strains.     

Spasmolytic activity of essential oil and various extracts of Ferula gummosa Boiss. on ileum contractions

Traditional herbal medicines such as Ferula gummosa Boiss. have been used for treatment of intestinal disorders in Iran. To date no pharmacological evidence for their effectiveness has been reported. The aim of this study was to examine the relaxant effect of essential oil, hydro-alcoholic, etheric, petrolic and methanolic extracts of Ferula gummosa and two of its components, alpha-pinene and beta-pinene, on isolated rat ileum contractions induced by KCl and acetylcholine (ACh). Ferula gummosa essential oil (FGEO) and hydro-alcoholic, etheric, petrolic and methanolic extracts all inhibited the response to 80 mM KCl in a concentration-dependent manner and attenuated the maximum attainable response of the ACh concentration-response curve. Although the effect of etheric extract on ACh contractions was less than that of petrolic extract, the overall order of effectiveness on the weight basis was the etheric, petrolic, methanolic, and hydro-alcoholic extracts, and the essential oil, respectively. A mixture of etheric and petrolic extracts together had a similar effect on KCl response to etheric extract was used alone. Alpha-pinene and beta-pinene both exhibited inhibitory effect on the contraction of rat ileum, but the inhibitory effect of beta-pinene on KCl contraction was more pronounced. The inhibitory effect of a mixture of these two compounds was, however, less than the sum of their separate effects. When a mixture of alpha-pinene and beta-pinene together were examined on the ileum, without presence of the spasmogen, they initially caused contraction of the tissue, while neither of them used alone caused a noticeable contraction of the ileum. This study shows that Ferula gummosa essential oil and its various extracts are relaxant of rat isolated ileum and that at least part of their inhibitory effect is due to alpha-pinene and beta-pinene components. As the inhibition of contractile over-activity of the ileum is the basis of the treatment of some gastero-intestinal disorders such as diarrhea, Ferula gummosa may have clinical benefits for treatment of this condition.     

Chemical composition,antioxidant and antimicrobial activities of the essential oil and methanolic extract of Ferulago bernardii Tomk. & M. Pimen of Iran

The aim of the study was to investigate chemical composition, antioxidant, antibacterial and antifungal activities of the essential oil (EO), polar and nonpolar sub-fractions of methanolic extract of Ferulago bernardii. The chemical constituent of the EO was identified by means of GC–MS. The antimicrobial activities of the EO, polar and nonpolar extracts were evaluated by micro-dilution and agar disc diffusion assays. The antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) free radical scavenging activity assay. The main components of the EO were α-pinene (35.03%), z-β-ocimene (14.24%) and bornyl acetate (11.64%). Bacillus cereus and Salmonella typhimurium were the most susceptible and resistant to the antibacterial activity of the essential oil and extract, respectively. The free radical scavenging activities of all extracts and the essential oil were in the order: polar > non-polar > EO. Our findings indicate that F. bernardii essential oil and methanolic extract has a potential to be applied as antimicrobial and antioxidant agent.     

Chemical composition and antimicrobial activity of essential oil from cones of Pinus koraiensis

The essential oil from the cones of Pinus koraiensis was prepared after removing the seeds, and its chemical composition analyzed using gas chromatography-mass spectrometry (GC-MS). Hydrodistillation of the P. koraiensis cones yielded 1.07% (v/w) of essential oil, which was almost three times the amount of essential oil extracted from the needles of the same plant. Moreover, the antimicrobial activities of the oil against the growth of Gram-positive bacteria, Gram-negative bacteria, and fungi were evaluated using the agar disc diffusion method and broth microdilution method. Eighty-seven components, comprising about 96.8% of the total oil, were identified. The most abundant oil components were limonene (27.90%), alpha-pinene (23.89%), beta-pinene (12.02%), 3-carene (4.95%), beta-myrcene (4.53%), isolongifolene (3.35%), (-)-bornyl acetate (2.02%), caryophyllene (1.71%), and camphene (1.54%). The essential oil was confirmed to have significant antimicrobial activities, especially against pathogenic fungal strains such as Candida glabrata YFCC 062 and Cryptococcus neoformans B 42419. Therefore, the present results indicate that the essential oil from the cones of Pinus koraiensis can be used in various ways as a nontoxic and environmentally friendly disinfectant.     

Studies on the chemical composition and biological activity of essential oil from Cyperus rotundus Linn.

The sesquiterpene caryophyllene in its alcohol form has been identified for the first time from the essential oil of the tubers of Cyperus rotundus Linn. The structure of the alcohol has been identified by spectroscopic and chemical methods. Bioefficacy of the oil and its hydrocarbon, ketonic and alcoholic fractions is reported for maize and mungbean.     

Chemical composition and inhibitory activity of essential oil from decaying leaves of Eucalyptus citriodora

A study was undertaken to explore the content and composition of volatile oil from decaying leaves of lemon-scented eucalypt (Eucalyptus citriodora Hook.) not analyzed earlier. GC and GC-MS analysis of the oil (yield 0.6%) revealed the monoterpenoid nature with citronellal (52.2%), citronellol (12.3%) and isoisopulegol (11.9%) as the major constituents. Overall, 17 components were identified that accounted for over 94% of the decaying leaf oil. Surprisingly, the decaying leaf oil contained nearly 1.8% of trans-rose oxide, which is generally absent in eucalypt essential oil. Decaying leaf oil and its major 2 components (citronellal and citronellol) inhibited the germination and root elongation of two weeds--Cassia occidentalis (broad-leaved) and Echinochloa crus-galli (grassy weed). Based on the dose-response studies, I50 values were determined for decaying leaf oil and the effect was more on germination only of broad-leaved weed (C. occidentalis), whereas that of citronellal and citronellol were on germination as well as root length of E. crus-galli (grassy weed). Based on I50 values it was observed that citronellal was more phytotoxic and germination inhibiting in nature, whereas citronellol was a more potent root inhibitor, thereby indicating a possible different mode of action. The study concludes that decaying leaf oil hold a good commercial value for exploitation as weed management agent.     

Antibacterial activity of the essential oil from Rosmarinus officinalis and its major components against oral pathogens

The essential oil of Rosmarinus officinalis L. (rosemary) was obtained by hydro-distillation and analysed by gas chromatography-mass spectrometry. Sixty-two constituents were identified, representing 98.06% of the total oil content. Oxygenated monoterpenes were the predominant components. The rosemary oil was characterized as having prominent (> 5%) contents of camphor (18.9%), verbenone (11.3%), a-pinene (9.6%), beta-myrcene (8.6%), 1,8-cineole (8.0%), and beta-caryophyllene (5.1%). The antimicrobial activity of the oil as well as of its major constituents was tested against the following microorganisms: Streptococcus mutans, Streptococcus mitis, Streptococcus sanguinis, Streptococcus salivarius, Streptococcus sobrinus, and Enterococcus faecalis, which are potentially responsible for the formation of dental caries in humans. The microdilution method was used for determination of the minimum inhibitory concentration (MIC) during evaluation of the antibacterial activity. The essential oil displayed low activity against the selected microorganisms. In the present study, the pure major compounds were more active than the essential oil. Among all the microorganisms tested, the pathogen S. mitis was the most susceptible and E. faecalis was the most resistant to the evaluated samples. This is the first report on antimicrobial activity of the major components of rosemary oil against oral pathogens.     

Chemical composition and antibacterial activity of the essential oil of Drimys granadensis L.f. leaves from Colombia

Drimys granadensis L.f., a native plant from Colombia, has been included in the Vademecum de Plantas Medicinales de Colombia by the Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, due to its widespread use in the folk medicine for the treatment of gastrointestinal ailments. The chemical composition of the essential oil of Drimys granadensis obtained by hydrodistillation of the leaves was analyzed by GC and GC/MS analyses. A total of 85 components were identified, with the major compounds germacrene D (1, 14.7%), sclarene (9.5%), a-cadinol (7.3%), longiborneol acetate (2, 6.3%), drimenol (4.2%), (Z)-β-ocimene (3, 4.2%), a-pinene (4, 3.2%), and β-elemene (5, 2.7%). The essential oil was also tested against eight bacteria using the Kirby-Bauer disk-diffusion method. Most of the Gram-positive bacteria tested were susceptible to the D. granadensis essential oil, while the Gram-negative bacteria tested were not.     

Evaluation of chemical composition and anti-inflammatory,antioxidant, antibacterial activity of essential oil of Sardinian Santolina corsica Jord. & Fourr.

Santolina corsica Jord. & Fourr. Corsican-Sardinian is an endemism almost present all around Corsica; in Sardinia, it can only be found in Monte Albo (calcareous substratum and poor in nutrients). The aim of our study is to investigate the chemical composition of S. corsica essential oils from plants growing in three different stations located at different altitudes and evaluate the biological activity using anti-inflammatory, antioxidant and antimicrobial test. The composition of the essential oils was determined by gas chromatography and gas chromatography/mass spectrometry. The essential oils of the Sardinian-Corsican endemism S. corsica, growing in Monte Albo, showed a great variability, probably due to genetic characters different from the Corsican type. We found three different chemotypes: artemisia ketone-β-fellendrene; myrcene and β-fellandrene-myrcene. Standard microbiological assays demonstrated that the essential oils collected in the selected stations, compared with oil and compound with demonstrated antibacterial activity, don’t have any antibacterial activity. DPPH test carried out on the tree samples, compared with chatechin, demonstrated that the oils don’t have antioxidant activity.Regarding anti-inflammatory activity the study demonstrated that the essential oils have a good anti-inflammatory activity on the bronchial tract.The addition of essential oil make easy the exocytose and the histiocytes can expel the anthracotic pigment into the culture medium, purifying its cytoplasm and restoring its ability to phagocytize more material. With a higher concentration of granulocytes in the sample, the incubation of cells shows a non-specific inflammatory pattern in which the addition of the essential oils has a positive impact on the decrease of granulocytes.More experiments are requested to confirm the data, but on the basis of these first results S. corsica essential oil showed potential activity against respiratory infections.     

Chemical composition and antimicrobial activity of the essential oil of Scutellaria barbata

The essential oil of Scutellaria barbata was obtained by hydrodistillation with a 0.3% (v/w) yield and analysed by GC and GC-MS. The main compounds in the oil were hexahydrofarnesylacetone (11.0%), 3,7,11,15-tetramethyl-2-hexadecen-1-ol (7.8%), menthol (7.7%) and 1-octen-3-ol (7.1%). The antimicrobial activity of the oil was evaluated against 17 microorganisms using disc diffusion and broth microdilution methods. The gram-positive bacteria, including methicillin-resistant Staphlococcus aureus, were more sensitive to the oil than gram-negative bacteria and yeasts.