Antimicrobial Activity Of Essential Oils Research Articles

Chemical composition and antimicrobial activity of essential oils from \(\textit{Angelica sinensis}\) (Oliv.) diels cultivated in Hung Yen province of Vietnam

Essential oils from roots, flowers, fruits, and leaves plus stems of Angelica sinensis cultivated in Vietnam were obtained by hydrodistillation and were analyzed using GC/MS-FID. In total, 36, 30, 33, and 27 compounds were found accounting for 98.7%, 98.8%, 99.2%, and 100% of the oils compositions, respectively. (Z)-Ligustilide (49.4%, 29.6%, 25.8%, 28.9%) and γ-terpinene (20.6%, 38.5%, 35.5%, 44.2%) were the main components of the respective essential oils. Especially, dictyopterene C (10.8%) was found to be one of the main components of fruit oil. Among the A. sinensis essential oil samples tested, the fruit oil revealed the strongest antimicrobial activity against bacteria Escherichia coli and yeast Candida albicans with median inhibitory concentration values of 0.97 and 0.15 mg/mL, respectively.

Chemical Composition and Antimicrobial Activity of Essential oil from Scales of Moroccan Juniperus phoenicea

Abstract-The essential oil of Juniperus phoenicea was obtained by hydrodistillation method using a Clevenger-type apparatus with a yield of 1.9 % and was analyzed by gas chromatography coupled to a mass spectrometer (GC-MS). Twelve volatile compounds were identified representing 99,85% of the total oil composition, while the α-pinene (78,31%), β-Myrcene (11,92%) and limonene (3,96%) were the major compounds. This essential oil was evaluated as an antibacterial and antifungal agent. The result showed that the oil presents a high biological activity as an antibacterial agent against the three tested strains Escherichia coli, Staphylococcus aureus and Pseudomonas aeroginos. It's also active as an antifungal agent against the Candida albicans with a zone inhibition of 28 mm. Keywords: Medicinal plant, Juniperus, phoenicea, Essential oil, Chemical composition, Antimicrobial activity.

Antimicrobial Activity and Chemical Composition of Essential Oils against Pathogenic Microorganisms of Freshwater Fish.

Antimicrobials are widely applied in aquaculture for treatment of infectious diseases in fish. The increased antimicrobial resistance of fish pathogens to conventional antimicrobial treatment highlights the need for research on the antibacterial properties of natural products—in this case, essential oils (EOs). The aim of the present study was to detect the antimicrobial activity of the essential oils on pathogenic microorganisms found in freshwater fish. Freshwater fish isolates of Aerococcus spp., Aeromonas spp., Enterococcus spp., Escherichia spp., Pseudomonas spp., Shewanella spp., Yersinia spp., and Vagococcus spp. were tested for antimicrobial resistance and antimicrobial activity against 14 commercially available essential oils. Antimicrobial resistance was identified in Pseudomonas spp. isolates against cefepime and ciprofloxacin; while all Aeromonas, Enterococcus, and Yersinia isolates were fully susceptible. All tested EOs revealed antimicrobial activity against the tested freshwater fish isolates at different extents. Cinnamomum camphora exhibited strong antimicrobial activity against Aeromonas spp. (3.12 μL/mL), Enterococcus spp. (0.78–1.56 μL/mL), and Pseudomonas spp. with the MIC method. EOs of Gaultheria procumbens and Litsea cubeba showed strong antibacterial activity against Yersinia spp. and Vacococcus spp. (6.25 μL/mL). The study shows the antimicrobial activity of EOs against the most relevant freshwater fish pathogens and indicates the application opportunities in aquaculture.

Insecticidal, antimicrobial and antioxidant activities of essential oil from Lavandula latifolia L. and its deterrent effects on Euphoria leucographa

Lavandula latifolia L. is a medicinal plant has fungicidal, antibacterial and antioxidant properties. The aim of this study was to determine the chemical composition, antioxidant and antimicrobial activities of essential oil (EO) of L. latifolia L. extracted by hydrodistillation method. A total of 22 constituents were identified in L. latifolia L. using Gas chromatography–mass spectrometry analysis. The compounds such as, gamma-terpinene (26.8 %), camphor (13.8 %), 1,8-cineole (10.2 %), lavandulol (9.3 %), terpinen-4-ol (9.1 %), linalool (8.9 %), b-elemene (3.2 %), b-pinene (3.1 %), 1,4-cineole (3.07 %), camphene (2.32 %), a-terpineol (2.3 %), and a-copaene (2.2 %) were determined. The antifungal activity of this EO against five phytopathogenic fungi revealed their broad-spectrum and strong antifungal properties. Notably, the EO showed potent activity on Trichophyton mentagrophytes (31 ± 1 mm) and the minimum inhibitory concentration value was 0.125 ± 0.05 μg/mL. The oil, analyzed for its DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS [2,2_-azinobis-(3-ethylbenzothiazoline-6- sulphonic acid)] free radical scavenging activity. Hydrodistilled EO had higher ABTS scavenging capacity than DPPH free radical scavenging power. Essential oil was used to test pesticide activity against Euphoria leucographa (Order: Coleoptera; Family: Scarabaeidae) infected in custard apple (Annona muricata) fruit. Results indicated that the spike lavender EO had contact toxicity on E. leucographa upon topical treatment. The effective concentration at 50 % (EC50) value of EC of L. latifolia L. was 0.37 % revealed considerable fumigant activity mainly due to the presence of fragrant compounds. Interestingly, custard apple (A. muricata) treated with EO effectively controlled the growth of T. mentagrophytes. Overall, antifungal and insecticidal properties of lavender EO, as a natural choice to preserve the harvested fruits thereby protecting the industrial crops.

Chemical Composition and Antimicrobial Activity of Essential oil from Scales of Moroccan Juniperus phoenicea

Abstract-The essential oil of Juniperus phoenicea was obtained by hydrodistillation method using Clevenger-type apparatus with a yield of 1.9 % and was analyzed by gas chromatography coupled to a mass spectrometer (GC-MS). Twelve volatile ompounds were identified representing 99,85% of the total oil composition, while the α-pinene (78,31%), β-Myrcene (11,92%) and limonene (3,96%) were the major compounds. This essential oil was evaluated as an antibacterial and antifungal agent. The result showed that the oil presents a high biological activity as an antibacterial agent against the three tested strains Escherichia coli, Staphylococcus aureus and Pseudomonas aeroginos. It's also active as an antifungal agent against the Candida albicans with a zone inhibition of 28 mm.

Synergistic Antimicrobial Activities of Combinations of Vanillin and Essential Oils of Cinnamon Bark, Cinnamon Leaves, and Cloves.

Plant bioactive compounds have antimicrobial and antioxidant activities that allow them to be used as a substitute for synthetic chemical additives in both food and food packaging. To improve its sensory and bactericidal effects, its use in the form of effective combinations has emerged as an interesting possibility in the food industry. In this study, the antimicrobial activities of essential oils (EOs) of cinnamon bark, cinnamon leaves, and clove and the pure compounds vanillin, eugenol, and cinnamaldehyde were investigated individually and in combination against Listeria monocytogenes and Escherichia coli O157:H7. The possible interactions of combinations of pure compounds and EOs were performed by the two-dimensional checkerboard assay and isobologram methods. Vanillin exhibited the lowest antimicrobial activity (MIC of 3002 ppm against L. monocytogenes and 2795 ppm against E. coli O157:H7), while clove and cinnamon bark EOs exhibited the highest antimicrobial activity (402–404 against L. monocytogenes and 778–721 against E. coli O157:H7). For L. monocytogenes, pure compound eugenol, the main component of cinnamon leaves and clove, showed lower antimicrobial activity than EOs, which was attributed to the influence of the minor components of the EOs. The same was observed with cinnamaldehyde, the main component of cinnamon bark EO. The combinations of vanillin/clove EO and vanillin/cinnamon bark EO showed the most synergistic antimicrobial effect. The combination of the EOs of cinnamon bark/clove and cinnamon bark/cinnamon leaves showed additive effect against L. monocytogenes but indifferent effect against E. coli O157:H7. For L. monocytogenes, the best inhibitory effects were achieved by cinnamon bark EO (85 ppm)/vanillin (910 ppm) and clove EO (121 ppm)/vanillin (691 ppm) combinations. For E. coli, the inhibitory effects of clove EO (104 ppm)/vanillin (1006 ppm) and cinnamon leaves EO (118 ppm)/vanillin (979 ppm) combinations were noteworthy. Some of the tested combinations increased the antimicrobial effect and would allow the effective doses to be reduced, thereby offering possible new applications for food and active food packaging.

Correlation between Genetic Variability, Chemical Composition and Antimicrobial Activity of Essential Oils Isolated from Avocado Cultivars Grown in Egypt

Persea americana Mill. (Lauraceae) has been successfully propagated in Egypt for the commercial production of avocado fruits. Four cultivars (one pure Mexican and three Mexican-Guatemalan hybrids) were investigated for the chemical composition and antimicrobial activity of their leaves' essential oils. The hydro-distilled oils from Bacon, Duke, Ettinger and Pinkerton cultivars were analyzed using Gas Chromatography/ Mass spectrometry (GC/MS) and Gas Chromatography/ Flame Ionization Detector (GC/FID). Total of 20 compounds were identified with estragole, methyl eugenol and -pinene as the major constituents. Chemometric analysis performed on the GC/FID data indicated close similarity between the essential oils of Bacon and Ettinger cultivars, while that of the Duke cultivar was the most distant. This classification was further supported by comparative DNA fingerprinting using Random Amplified Polymorphic DNA (RAPD) technique. Essential oils of all cultivars had no antifungal activity against Candida albicans or Aspergillus niger but showed good antimicrobial activities against Streptococcus mutans and Salmonella typhimurium with IC50 values between 0.4 and 20 L/mL

Evaluation of Antibacterial and Antioxidant Activities of Essential Oil of Lime (Citrus aurantifolia) Pomace Powder

This study aimed to determine the chemical compounds, antioxidant and antimicrobial activities of Essential Oil (EO) derived from lime pomace. Gas chromatography/mass spectrometry (GC-MS) was used to determine the major components of the obtained EO. The antioxidant activities of this EO were determined by radical scavenging activity (DPPH) and the Ferric Reducing Antioxidant Power (FRAP) test. For antimicrobial activity, the disk diffusion method was used and the Minimum Inhibitory Concentrations (MIC) and the Minimum Bactericidal Concentration (MBC) were studied against common foodborne pathogens including; Staphylococcus aureus, Bacillus cereus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. The result showed that the Gram-positive bacteria were more susceptible than gram-negative bacteria. The result shows that lime pomace powder with IC50 83.061 mg/mL has a high antioxidant capacity and also, the chemical analysis of the EO showed that the EO contained a complex mixture of several components and the main constituents were D-limonene (28.86%), α- terpinene (15.65%) and γ-terpinene (12.72%) respectively.

Chemical Composition and Antimicrobial Activity of Essential oil from Scales of Moroccan Juniperus phoenicea

The essential oil of Juniperus phoenicea was obtained by hydrodistillation method using a Clevenger-type apparatus with a yield of 1.9 % and was analyzed by gas chromatography coupled to a mass spectrometer (GC-MS). Twelve volatile compounds were identified representing 99,85% of the total oil composition, while the α-pinene (78,31%), β-Myrcene (11,92%) and limonene (3,96%) were the major compounds. This essential oil was evaluated as an antibacterial and antifungal agent. The result showed that the oil presents a high biological activity as an antibacterial agent against the three tested strains Escherichia coli, Staphylococcus aureus and Pseudomonas aeroginos. It's also active as an antifungal agent against the Candida albicans with a zone inhibition of 28 mm

Insecticidal potentials of dry powder and solvent extracts of Tithonia diversifolia (Hemsl.) A. Gray flower against rice meal moth, Corcyra cephalonica (Stainton)

Insecticidal potentials of dry powder and solvent extracts of Tithonia diversifolia (Hemsl.) A. Gray flower against rice meal moth, Corcyra cephalonica (Stainton)

Chemical Composition and Antimicrobial Activities of Essential Oil from the Leaves of Acalypha wilkesiana on Pathogenic Microorganisms

Acalypha wilkesiana is a tropical plant used to treat a wide range of medical conditions. The leaves of A. wilkesiana were tested for phytochemicals with microbicide activity against a variety of microorganisms known to cause severe human infections. Antimicrobial efficacy of essential oil extracts from pulverised dried leaves of A. wilkesiana was examined. Phytochemical and proximate assessments of the leaves were carried out using standard techniques. The essential oil was extracted using hydro-distillation and collected using two processes. The first form was extraction for four hours straight, and the second mode involve hourly collection for four times. A total of five fractions of the essential oil were extracted. The chemical constituent of the oil was separated with Gas chromatography–mass spectrometry (GC-MS) in accordance with standard procedures. The proximate composition of leaves showed low moisture and high carbohydrate (61.39%). Tannins, flavonoids, and alkaloids were among the secondary metabolites found in the leaves. Six bioactive compounds including n-Hexadecanoic acid and 6-Benzamido-4-benzoyl-1, 2, 4-triazine-3, 5 were identified in the GC–MS analysis. The oils from A. wilkesiana leaves have excellent broad-spectrum antimicrobial activity at various concentrations on Staphylococcus species, Bacillus coagulans, Escherichia coli, Klebsiella pneumoniae, Salmonella typhimurium and Candida albicans. It could not, however, inhibit the growth of Pseudomonas aeruginosa and Gardnerella vaginalis. The findings justify the usage of A. wilkesiana leaves in ethnomedicine for possible management of skin conditions, gastrointestinal problems as well as other related microbial infections.

Antimicrobial Activity and Chemical Composition of Essential Oil from Thymus daenensis and Thymus fedtschenkoi During Phenological Stages

Variation in chemical composition and biological activity of essential oils of medicinal plants may be observed due to the developmental stage of collected plant materials. In the present study, we compared the chemical compositions and antimicrobial activity of the essential oils from the aerial part of Thymus daenensis Celak. and Thymus fedtschenkoi Ronniger at different developmental stages. The highest essential oil content in both species was observed at the full flowering stage. The phenolic monoterpene thymol (71.9-73.9 %) and the monoterpene alcohol linalool (45.5-83.1 %) were the most abundant constituents at all phenological stages of T. daenensis and T. fedtschenkoi, respectively. All the essential oils possessed high antibacterial and antifungal activities against the microorganisms tested (Staphylococcus aureus, Bacillus cereus, Enterococcus faecium, Escherichia coli, Salmonella enteritidis, and Candida albicans), although of different degrees. The essential oils from T. fedtschenkoi appeared to be more active on almost all bacterial and fungal strains than that of T. daenensis (with MIC values of 1-16 mg/ml and 2-32 mg/ml, respectively). The effect of the plant phenological stage on the antimicrobial activity and constituents of T. fedtschenkoi essential oil was more pronounced than for T. daenensis. Interestingly, the antimicrobial effects of T. fedtschenkoi essential oil obtained at the seed set stage was noteworthy against all tested microorganisms, apart from the resistant E. faecium. Overall, this study highlighted the importance of the choice of the harvesting time to achieve the optimum of essential oil quality and quantity together with the antimicrobial activities, which are exploited in the pharmaceutical and food industries.

Chemical Composition and Antimicrobial Activity of Essential Oils from the Leaves and Stems of Tinomiscium petiolare Hook.f. & Thomson from Vietnam

Essential oils from the leaves and stems of Tinomiscium petiolare Hook.f. & Thomson were obtained by hydrodistillation and the chemical components were determined by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS). Also, the microdilution broth assay was used to test the antimicrobial activity of essential oils. The respective yields of the T. petiolare leaf and stem essential oils were 0.06 % and 0.04 % (v/w), calculated on a dry weight basis. The major components (percentages, respectively) identified from the leaf and stem essential oils of T. petiolare were relatively similar, comprising of β-bisabolene (11.43 % and 13.80 %), trans-α-bergamotene (6.52 % and 6.61 %), geranyl acetate (6.12 % and 5.77 %), (E)-caryophyllene (5.04 % and 4.73 %), δ-cadinene (4.10 % and 5.27 %), (E,E)-α-farnesene (4.54 % and 4.65 %) and α-zingiberene (3.85 % and 4.50 %). The antimicrobial activity test indicated that T. petiolare stem essential oil displayed moderate activity against Staphylococcus aureus ATCC 6538 with Minimum inhibitory concentration (MIC) value of 200 μg/mL, while both essential oils inhibited the growth of Pseudomonas aeruginosa ATCC 9027 with MIC value of 200 μg/mL. The chemical components and antimicrobial activity of the T. petiolare leaf and stem oils are reported for the first time.

Variability in chemical composition and antimicrobial activity of essential oil of Rosa\u2009\xd7\u2009damascena Herrm. from mountainous regions of Iran

BackgroundEssential oil of Rosa × damascena Herrm. is one of the most valuable and important raw materials for the flavor and fragrance industry. The cultivation of this plant has ancient origins, and Kashan was one of the first mountainous regions of Iran dealing with the cultivation of R. × damascena. In this study, both chemical composition and antimicrobial activity of different rose essential oils obtained from five mountainous areas of Kashan region (Maragh, Qamsar, Sadeh, Javinan, and Kamoo) has been investigated along with the influence of the environmental conditions on these properties.ResultsResults showed that yield and chemical composition of essential oils obtained from Rosa × damascena were significantly affected by the collection area. In particular, the yield of oils varied from ~0.08 to ~0.132% and citronellol (36.70-9.18%), geraniol (12.82-0.47%), nonadecane (22.73-10.36%), heneicosane (31.7-11.43%), and 1-nonadecene (6.03-3.93%) have been detected as main compounds in all the plants collected, but at different concentrations depending on the collection area. The best fragrance and the highest yield were found in the oil from Kamoo area. Similarly to the chemical composition, the antimicrobial activity of the essential oils was affected by their origin, and essential oil obtained from plants collected from Kamoo area disclosed the highest antibacterial and antifungal efficacy. Its inhibition halos were 17.33±0.58 mm against Aspergillus brasiliensis, 15.67±0.58 mm against Staphylococcus aureus, and 12.33±0. 58 mm against Streptococcus pyogenes. Essential oils of R. damascena were also effective against Gram-negative Pseudomonas aeruginosa and they had a MIC value of 62.50 μg/mL irrespective of the collection area (except the oil from Javinan area). On the contrary, the highest antifungal power against Candida albicans yeast was reached using the essential oil obtained from plants collected in Javinan region (MIC and MBC ~62.50 μg/mL).ConclusionsOverall results underline the influence of environmental conditions of the different areas of Kashan region, on the chemical composition of and antimicrobial activity of the essential oils of Rosa × damascena. In addition, results disclosed that Kamoo seemed to be the most suitable area for the competitive cultivation of R. × damascena to the intensive production of aromatic flower oil and natural antimicrobial essential oils.

Chemical Composition and Antibacterial Activity of Essential Oil Extracted from Citrus sinensis L., Citrus limon L. and Zingiber officinale Roscoe

Postharvest loss is a serious problem in Nigeria and a major drawback towards food security. Hence, discovery of potential agents capable of minimizing postharvest loss is urgently needed. This research is directed at investigating the in vivo antimicrobial activity of essential oils against bacterial pathogens isolated from Ipomoea batatas Lam. Citrus sinensis (sweet orange) and Citrus limon (lemon) peels and Zingiber officinale (ginger) essential oils were extracted using hydro-distillation and their chemical constituents determined by gas chromatography mass spectrometry (GC-MS). Morphological and biochemical methods were employed for bacterial identification. A total of 22 terpenes were identified with Citrus sinensis comprising of 13 monoterpenes, 8 sesquiterpenes and 1 diterpene. Citrus limon had 31 terpenes 15 of which are monoterpenes, 15 sesquiterpenes and 1 diterpene while a total of 30 terpenes were identified with Zingiber officinale comprising of 12 monoterpenes and 18 sesquiterpenes. Three of the four isolated bacteria identified from Hannah sweet potato were pathogenic: Erwinia carotovora, Bacillus licheniformis and Pseudomonas fluorescens. Pseudomonas fluorescens was more sensitivity to the essential oils at (p≤0.05). Citrus sinensis (64.29%) was three fold more active than Citrus limon (21.43%), while Zingiber officinale (53.57%) was two and a half fold more active than Citrus limon. Results obtained in this study showed that essential oils extracted from Citrus sinensis and Zingiber officinale exhibited substantial antimicrobial activity against bacterial induced sweet potato rot. Therefore, essential oils extracted from Zingiber officinale and Citrus sinensis could be used to control postharvest bacteria induced rots in injured sweet potatoes.

Chemical Composition and Antimicrobial Activity of Essential Oil and Hydrosol Extract From Roots of Plumbago europaea and in-vitro Combinatory Antimicrobial Effect of Hydrosol Extract with Gentamicin and Amphotericin B

Background: Infectious diseases are responsible for millions of deaths a year worldwide. Antibiotics, which have saved so many lives and improved life expectancy, may become ineffective due to a worrying increase in bacterial resistance. Some of the appropriate actions that could be initiated to address this problem are to develop and search for new antimicrobial substances from medicinal plants, and combine antibiotics with antimicrobials agents isolated from a reservoir of bioactive natural products. Objectives: The purpose of this work was to study the chemical composition of the essential oil and hydrosol extract of Plumbago europaea, to evaluate their in-vitro antimicrobial activities and evaluate in-vitro combinatory antimicrobial effect of hydrosol extract with Gentamicin and Amphotericin B against a large panel of microorganisms in an effort to reduce their minimum effective dose and minimizing their side effects. Methods: The essential oil and hydrosol extract obtained from roots of Plumbago europaea were analyzed by GC/MS and tested for their antibacterial and antifungal activities against twelve different strains of microorganisms. The effectiveness, in-vitro, of the association between the hydrosol extract and both Gentamicin and Amphotericin B was also investigated using the checkerboard method. Results: The obtained results revealed that nine and four components, representing for 92.4 % and 97.4% of the total essential oil and hydrosol extract composition were identified, respectively and hydrosol extract was more active than the essential oil against all screened microorganisms, with interesting MIC values (19 μg/mL). An important effect of hydrosol extract was obtained in decreasing the MIC of Gentamicin and Amphotericin B in all tested combinations. Conclusion: The in-vitro combination of the hydrosol extract with Gentamicin and Amphotericin B led to substantial MIC reduction against all tested microorganisms. This combination can help to reduce the minimum effective dose of antimicrobial drugs used, which may help to decrease their side effects; and deliver these medicines with similar potency.

Monarda essential oils as natural cosmetic preservative systems

The aim of the study was (1) to compare the antimicrobial activity of essential oils (EOs) obtained from leaves and inflorescences of Monarda media, Monarda didyma and Monarda citriodora found in different phenological stages of development, (2) to examine the inhibition of microbial growth by Monarda EOs in O/W emulsions. Thymol, p-cymene and carvacrol were the main constituents in Monarda EOs. The strongest antimicrobial activity were obtained from the leaves of Monarda EOs in the flowering phase of the development. M. media EO fulfilled the criterion of the preservative effectiveness test for all tested bacteria and fungi, while M. didyma and M. citriodora EOs does not meet criterion for Gram-negative bacteria. M. media EO can be an effective candidate for a natural cosmetic preservatives and finally create self-preserving system in O/W emulsion, while M. didyma and M. citriodora EOs can only reduce concentration of synthetic preservatives in O/W emulsions.

Evaluation of the Antimicrobial Activity of Some Components of the Essential Oils of Plants Used in the Traditional Medicine of the Tehuacán-Cuicatlán Valley, Puebla, México.

In Tehuacán-Cuicatlán valley (Mexico), studies have been carried out on the essential oils of medicinal plants with antimicrobial activity and it was found that they present compounds in common such as: α-pinene, β-pinene, carvacrol, eugenol, limonene, myrcene, ocimene, cineole, methyl salicylate, farnesene, and thymol. The goal of this study was to assess the antimicrobial activity of essential oils’ compounds. The qualitative evaluation was carried out by the Kirby Baüer agar diffusion technique in Gram-positive bacteria (11 strains), Gram-negative bacteria (18 strains), and yeasts (8 strains). For the determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), the agar dilution method was used. All the evaluated compounds presented antimicrobial activity. The compounds eugenol and carvacrol showed the largest inhibition zones. Regarding yeasts, the compounds ocimene, cineole, and farnesene did not show any activity. The compounds eugenol, carvacrol, and thymol presented the lowest MIC; bactericidal effect was observed at MIC level for S. aureus 75MR, E. coli 128 MR, and C albicans CUSI, for different compounds, eugenol, carvacrol, and thymol. Finally, this study shows that the essential oils of plants used by the population of Tehuacán-Cuicatlán valley share compounds and some of them have antibacterial and fungicidal activity.

Chemical Compositions of Essential Oils and Antimicrobial Activity of Elettariopsis triloba from Vietnam

The herb, Elettariopsis triloba (Gagnep.) Loes. (syn. Amomum trilobum Gagnep. or Elettariopsis trilobum (Gagnep.), has been used ethnomedically for the treatment of rabies, inflammation and amelioration of microbial infections. We report herein the chemical constituents and antimicrobial activity of the rhizome essential oil of E. triloba from north-central Vietnam. The technique of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS) was used to analyze the oil sample while the microdilution assay was employed to determine the antimicrobial efficacy. Monoterpene compounds including camphene (23.2 %), fenchyl acetate (12.7 %), bornyl acetate (10.6 %), α-pinene (5.7 %) and limonene (5.1 %) were the main constituents of the rhizome essential oil. The essential oil displayed antimicrobial activity only towards Gram-positive bacteria of Enterococcus faecalis ATCC 299212, Staphylococcus aureus ATCC 25923 and Bacillus cereus ATCC 14579 with minimum inhibitory concentration (MIC) values of 16.0 μg/mL, 256 μg/mL and 32.0 μg/mL, respectively. The oil also inhibited the growth of the yeast, Candida albicans ATCC 10231, with a MIC value of 16.0 μg/mL. The chemical constituents and antimicrobial activity of essential oil from E. triolba were being reported for the first time and validation of the ethnomedicinal usage of the plant.

Chemical Composition and Anti-microbial Activity of Essential Oil from Aerial parts of Origanum vulgare L. from North-Western Himalayas

Origanum vulgare L. is an important aromatic medicinal plant, which has many medicinal properties and is used in the cosmetics and pharmaceutical industries. This study aims to evaluate the chemical composition and anti-microbial activities of essential oil extracted from aerial parts of a wild-growing O. vulgare L. The plant has been collected from the North-Western Himalayas region (Himachal Pradesh, India) and essential oil from its aerial part has been isolated through hydro-distillation. Gas chromatography/mass spectroscopy (GC/MS) analysis of the essential oil has been carried out to reveal its chemical composition. A total of twenty-four constituents have been identified, out of which eight constituents were different than reported in other studies, most probably due to geographical (height, temperature, soil, flora, and fauna) and geological (plants and animals) conditions. This essential oil has been dominated by oxygenated sesquiterpenes-38.08 %, followed by phenolic monoterpenoids-20.39 %, sesquiterpene hydrocarbon-14.4 %, monoterpene hydrocarbon-5.75 %, aliphatic alcohols-4.35 %, oxygenated monoterpene-3.99 %, polycyclic aromatic hydrocarbon-2.55 %, and sesquiterpenoid alcohol-2.26 %. Caryophyllene oxide (38.08 %) and thymol (20.39 %) have been found as major chemical components of essential oil. Anti-microbial activity of essential oil of O. vulgare has shown the highest zone of inhibition against the fungus Aspergillus niger (14 mm) and lowest against the Gram +ve bacteria Staphylococcus aureus (6 mm) at 600 ppm concentration among the all tested strains.