Major Components Of Essential Oil Research Articles

Restoration of delayed gastric emptying and impaired gastric compliance by anethole in an animal model of functional dyspepsia

Background and AimsFunctional dyspepsia (FD) is a functional gastrointestinal disorder characterized by persistent or recurrent postprandial upper‐abdominal discomfort and epigastric pain. Although FD markedly reduces the patient's quality of life, involving elevates health‐care costs, treatment of this condition by methods other than prescribed medicines, such as natural products, could be beneficial. Delayed gastric emptying and impaired gastric accommodation play important roles in pathogenesis of FD. Anethole (1‐methoxy‐4‐((E)‐propenyl)‐benzene), a major component in essential fennel oil has been used in flavouring, alcoholic beverage production and pharmaceutical formulations. In this study, we examined the effects of anethole on delayed gastric emptying and impaired gastric compliance in animals.MethodsGastric emptying was monitored by phenol red marker method in mice. Induction of delayed gastric emptying was performed by the administration of clonidine, dopamine or a 5‐HT3 receptor agonist m‐CPBG. Gastric accommodation (compliance test) was examined in rats by a pressure‐volume control device, barostat. Acetylcholinesterase activity was measured using assay kitResultsOral administration of anethole restored delayed gastric emptying induced by clonidine administration. The dose of anethole did not affect gastric emptying in non‐stressed mice. We also found that fennel oil, which contains about 86% anethole, suppressed clonidine‐induced delayed gastric emptying. Furthermore, a Japanese herbal medicine An‐chu‐san containing anethole improved the gastric emptying in the presence of clonidine. Pharmacological and biochemical analyses suggested that anethole restores gastric emptying independently of D2, 5‐HT3, 5‐HT4 receptors and acetylcholinesterase. Finally, anethole stimulated gastric compliance in rats both with and without wrap restraint stress.ConclusionsTaken together, our results suggest that anethole could be beneficial for treatment of postprandial distress and early satiety in patients with FD.Support or Funding InformationThis research received no specific grant from any funding agency in the public, commercial, or not‐for‐profit sectors.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Valorization of essential oils from two populations (wild and commercial) of Geranium macrorrhizum L.

The insecticidal and acaricidal effects of the essential oils (EO) from two populations of Geranium macrorrhizum L (ornamental variety Bevan, VB and wild population from Hungary, GH) have been studied against several insect pests of economic importance in agriculture (Spodoptera littoralis, Myzus persicae and Rhopalosiphum padi), and the hard tick Hyalomma lusitanicum. The oil from the wild population (GH) was characterized by its content in β-elemenone (30.53%), thymol (18.52%) and germacrone (15.54%), while the oil from the commercial variety (VB) had linalool (26.45%) and linalyl acetate (25.11%) as major components. S.litoralis and R. padi were significantly affected by the wild population oil (GH-EO). The oil from the commercial variety VB was less effective against insects. The ixodicidal effects of these oils were strong, being the wild population (GH-EO) the most effective. To correlate the composition of these oils with their activity, the essential oil major components have been isolated (germacrone and β-elemenone) and tested (linalool, thymol, germacrone and β-elemenone). The insect antifeedant and ixodicidal effects of thymol and germacrone explained the bioactivity of the GH essential oil. Therefore, the wild variety of G. macrorrhizum has been selected for domestication given its potential as a source of bioactive extracts and metabolites.

Antibacterial Effect of Carvacrol and Coconut Oil on Selected Pathogenic Bacteria

Abstract Essential oils play a prominent role as flavouring agents and fragrances in the food and perfume industries. Carvacrol is a major component of various essential oils, such as oregano and thyme oils, and is responsible for their antimicrobial activity. Lauric acid is a medium-chain fatty acid (MCFA) with a high antibacterial potential. Both carvacrol and MCFAs have been used empirically as antimicrobial agents. Here, we tested the inhibitory properties of carvacrol and coconut (Cocos nucifera L.) oil containing a high percentage of MCFAs against 5 harmful bacterial pathogens: Escherichia coli, Salmonella Enteritidis, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus cecorum. Gas chromatography (GC-FID) analysis of coconut oil showed a high concentration of lauric acid (41%). Microdilution antimicrobial assays showed that the combination of carvacrol and coconut oil had a stronger antibacterial effect against all tested bacteria than both agents separately. We conclude that carvacrol could significantly improve the antibacterial effect of coconut oil.

Novel high value elemicin-rich germplasm of lemon grass (Cymbopogon khasianus (Hack)Stapf(ex Bor) from North East India

Genus Cymbopogon is a valuable medicinal and aromatic grass of the world. The objective of the experiment was to identify elemicin rich genotype of Cymbopogon khasianus. Elemicin is widely used as a perfumery chemical as well as starting material for the synthesis of mescaline, an important alkaloid. Moreover it can also be used in confectionery, condiments, non-alcoholic beverages etc. In this experiment total forty eight accessions of Cymbopogon khasianus were collected from different parts of Meghalaya and planted in complete randomized block design with three replications at experimental farm of CSIR-NEIST in the year 2013.Morphological data recording and its oil constituents were analysed during the year 2013–14 and 2014–15. On the basis of two years selection trial data a new and distinct elemicin rich strain of Cymbopogon khasianus was identified and named as Jor Lab L-10. This new genotype was planted in the year 2015–16 and 2016–17 in multi-location trials at four different locations and the results were found to be stable and contented. The average oil yield of all multi-location trial was 0.40% which comprises of 70% elemicin content and 175% superior in the term of elemicin content from the check variety. Essential oil was extracted through hydro distillation method and the quantification was done by GC and GC–MS instrument. In GC and GC–MS analysis it was found that elemicin was the major component of essential oil while cis-asarone, β-ocimene, methyl eugenol, limonene, germacrene-D, transneral acetate, camphene, α-pinene, geranyl acetate, caryophyllene and trans-β- farnesene etc. were the minor compounds. Till date none of the elemicin rich (>70%) variety of lemon grass is reported and we first time identified a novel elemicin rich variety.

Risk management of ochratoxigenic fungi and ochratoxin A in maize grains by bioactive EVOH films containing individual components of some essential oils

Aspergillus steynii and Aspergillus tubingensis are possibly the main ochratoxin A (OTA) producing species in Aspergillus section Circumdati and section Nigri, respectively. OTA is a potent nephrotoxic, teratogenic, embryotoxic, genotoxic, neurotoxic, carcinogenic and immunosuppressive compound being cereals the first source of OTA in the diet. In this study bioactive ethylene-vinyl alcohol copolymer (EVOH) films containing cinnamaldehyde (CINHO), linalool (LIN), isoeugenol (IEG) or citral (CIT) which are major components of some plant essential oils (EOs) were produced and tested against A. steynii and A. tubingensis growth and OTA production in partly milled maize grains. Due to the favourable safety profile, these bioactive compounds are considered in the category “GRAS”. The study was carried out under different water activity (0.96 and 0.99 aw), and temperature (24 and 32 °C) conditions. ANOVA showed that class of film, fungal species, aw and temperature and their interactions significantly affected growth rates (GR), ED50 and ED90 and the doses for total fungal growth inhibition and OTA production. The most effective EVOH films against both species were those containing CINHO. ED50, ED90 and doses for total growth and OTA inhibition were 165–405, 297–614, 333–666 μg of EVOH-CINHO/plate (25 g of maize grains), respectively, depending on environmental conditions. The least efficient were EVOH-LIN films. ED50, ED90 and doses for total growth and OTA inhibition were 2800–>3330, >3330 and >3330 μg of EVOH-LIN/plate (25 g of maize grains), respectively. The effectiveness of the bioactive films increased with increasing doses. Overall, A. tubingensis was less sensitive to treatments than A. steynii. Depending on the species, aw and temperature affected GR and OTA production in a different way. In A. steynii cultures, optimal growth occurred at 0.96 aw and 32 °C while optimal OTA production happened at 0.99 aw and 32 °C. In A. tubingensis cultures optimal growth happened at 0.99 aw and 32 °C, although the best conditions for OTA production were 0.99 aw and 24 °C. Thus, these species can be very competitive in warm climates and storage conditions. The EVOH-CINHO films followed by EVOH-IEG and EVOH-CIT films, designed in this study and applied in vapour phase, can be potent antifungal agents against A. steynii and A. tubingensis and strong inhibitors of OTA biosynthesis in maize grains at very low doses. This is the first study on the impact that interacting environmental conditions and bioactive films containing individual components of EOs have on the growth of these ochratoxigenic fungi and on OTA production in maize grains.

Essential Oil Chemotype of Iranian Ajowan (Trachyspermum ammi L.)

The essential oil chemotype of an Iranian ecotype of ajowan was identified using gas chromatography mass spectrometry (GC-MS) analysis. Fifteen chemical compounds of essential oils were identified using GC-MS analysis. Thymol, ρ-cymene and γ-terpinen were identified as major components in essential oil of investigated ecotype with 54.32, 21.74, and 19.38 percentages, respectively. Only 0.42 % of the decomposed essential oil was related to carvacrol. Based on the results of the present study, thymol was the predominant composition in the essential oil of investigated ecotype of ajowan and these results can help to purposeful use of this ecotype in pharmaceutical industry, traditional medicine, and other industries.

Essential oil composition, total phenolic content, antioxidant and antibiofilm activities of four Origanum species from southeastern Turkey

ABSTRACTThis study reports a comparative screening of four species of Origanum in Turkey, based on their essential oil composition, total phenolic content, antioxidant and antibiofilm activities. The major components of essential oils were p-cymene, linalool, and thymol. The total phenolic contents differed from 3.81 to 47.54 mg of GAE/g of extract. The concentrations of flavonoids varied from 12.74 to 58.39 mg of Ru/g of extract. Antioxidant activity was determined in vitro using DPPH reagent and expressed as concentration of each extract required to inhibit radical by 50% (IC50) values that ranged from 16.03 to 48.94 μg/ml. Our results indicated that chloroform extracts of species O. majorana and O. onites, with a total content of polyphenols (47.54 mg of GAE/g and 45.17 mg of GAE/g, respectively) and an IC50 of 16.03 μg/ml and 16.89 μg/ml, respectively were more antioxidant. Among the essential oil concentrations tested, maximum antibiofilm activity was found as 92.24% against M. luteus NRRL-B 1013 by O. majorana essential oil at 50 mg/ml.

Green Chemistry: Strategy in Essential Oils Sustainability by Development of Insecticide Using Docking Method

Sustainable agricultural applications in green chemistry was associated with the development of insecticide production based on secondary metabolites, such as essential oils. This research used In Silico modeling for insecticide formulation based on essential oils. The insecticidal formula was made on the basis of the Ki value of multiple docking results between the major components of essential oils as ligand with Spodotera litura receptor (2DJC) studied using Autodock Tools software. Insecticide formula activity test was done by contact method of toxic and leaf contact with essential oils concentration at level 0% - 1%. The results of the in silico study showed that the inhibition constants (Ki) of citronellal and anethol ligands combination were 1.6 mM however of citronellal and eugenol as ligands were 1.75 mM and formulated rasio (v/v), respectively 5 : 1 and 4 : 1. In addition, in vitro activity of insecticide formula with the ratio of 5: 1 possess LC50 value 0.10% (toxic contact) and 0.35% (leaf contact). While the formula with a ratio of 4: 1 possess LC50 value 0.05% (toxic contacts) and 0.31% (leaf contact).

Characteristics of microcapsule of red ginger (Zingiber officinale var. Rubrum) essential oil produced from different Arabic gum ratios on antimicrobial activity toward Escherichia coli and Staphylococcus aureus

ABSTRACTEssential oil has antimicrobial activity. Encapsulation of essential oil might affect its antimicrobial activity. The present study was aimed to study the characteristic of red ginger essential oil microcapsule obtained from varying Arabic gum ratios on the growth inhibition of E. coli dan S. aureus. Red ginger essential oil from steam distillation was coated using Arabic gum with ratio 1:3, 1:4, 1:5 (w/b). The 1:3 (v/w) ratio of red ginger essential oil and Arabic gum showed the best microcapsule characteristics with average inhibition diameter zones 5.67 mm for E. coli and 6.67 mm for S. aureus, and reduction of bacterial count for E. coli 1.8 log CFU/g and S. aureus 2.3 log CFU/g, yield of microcapsule 51.54%, water activity 0.207, water content 3.57%, solubility 97.46%, surface oil 0.08%, and particle size 258.2 µm. The major component of red ginger essential oil was ar-curcumene, zingiberen, β-bisabolene, β-sesquiphellandrene, and camphene.

The Investigation on Drug Yield and Some Quality Characteristics of Mountain Tea (Sideritis congesta) Cultivated in Turkey

This research has been conducted under Konya ecological conditions to determine the effect on yield and quality some characters of nitrogen fertilizers applied at the different doses of Sideritis congesta in Medicinal Plants laboratory and Medicinal Plants Experimental Farm of Agriculture Faculty, Selcuk Universty. Experiment was designed and applied in randomized complete plotdesign with three replications in the year of 2012-2013. According to results of this researh; the plant height of Sideritis congesta was varied between 58.66-64.33 cm, the number of flowering branches 49.00-55.00, fresh flowering yield 446.66 - 623.33 kg/da, essential oil yield 0.24-0.33 % and major essential oil component (β –pinene) 43.24 and 48,45. The highest drug flower yield and essential oil yield for mountain tea in Konya and similar ecology 10 kg/da nitrogen fertizer application is reasonabled.

The effect of essential oils on microbial composition and quality of grass carp (Ctenopharyngodon idellus) fillets during chilled storage

Antimicrobial and antioxidant effects of essential oils (oregano, thyme, and star anise) on microbial composition and quality of grass carp fillets were investigated. Essential oils treatment was found to be effective in inhibiting microbial growth, delaying lipid oxidation, and retarding the increase of TVB-N, putrescine, hypoxanthine, and K-value. Based on sensory analysis, shelf-life of grass carp fillets was 6days for control and 8days for treatment groups. Among the essential oils, oregano essential oil exhibited the highest antimicrobial and antioxidant activities. GC-MS analysis of essential oils components revealed that carvacrol (88.64%) was the major component of oregano essential oil. According to the results of high-throughput sequencing, Aeromonas, Glutamicibacter, and Aequorivita were the predominant microbiota in fresh control samples. However, oregano essential oil decreased the relative abundance of Aeromonas, while thyme and star anise essential oils decreased the relative abundance of Glutamicibacter and Aequorivita in fresh treated samples. The microbial composition of both control and treatment groups became less diverse as storage time increased. Aeromonas and Pseudomonas were dominant in spoiled samples and contributed to fish spoilage. Compared to the control, essential oils effectively inhibited the growth of Aeromonas and Shewanella in grass carp fillets during chilled storage.

Salicylic Acid-Regulated Antioxidant Mechanisms and Gene Expression Enhance Rosemary Performance under Saline Conditions.

Salinity stress as a major agricultural limiting factor may influence the chemical composition and bioactivity of Rosmarinus officinallis L. essential oils and leaf extracts. The application of salicylic acid (SA) hormone may alleviate salinity stress by modifying the chemical composition, gene expression and bioactivity of plant secondary metabolites. In this study, SA was applied to enhance salinity tolerance in R. officinallis. R. officinallis plants were subjected to saline water every 2 days (640, 2,000, and 4,000 ppm NaCl) and 4 biweekly sprays of SA at 0, 100, 200, and 300 ppm for 8 weeks. Simulated salinity reduced all vegetative growth parameters such as plant height, plant branches and fresh and dry weights. However, SA treatments significantly enhanced these plant growth and morphological traits under salinity stress. Salinity affected specific major essential oils components causing reductions in α-pinene, β-pinene, and cineole along with sharp increases in linalool, camphor, borneol, and verbenone. SA applications at 100–300 ppm largely reversed the effects of salinity. Interestingly, SA treatments mitigated salinity stress effects by increasing the total phenolic, chlorophyll, carbohydrates, and proline contents of leaves along with decline in sodium and chloride. Importantly, this study also proved that SA may stimulate the antioxidant enzymatic mechanism pathway including catalase (CAT), superoxide dismutase (SOD), and ascorbate peroxidase (APX) as well as increasing the non-enzymatic antioxidants such as free and total ascorbate in plants subjected to salinity. Quantitative real-time PCR analysis revealed that APX and 3 SOD genes showed higher levels in SA-treated rosemary under salinity stress, when compared to non-sprayed plants. Moreover, the expression level of selected genes conferring tolerance to salinity (bZIP62, DREB2, ERF3, and OLPb) were enhanced in SA-treated rosemary under salt stress, indicating that SA treatment resulted in the modulation of such genes expression which in turn enhanced rosemary tolerance to salinity stress.

Identification of terpenes and essential oils by means of static headspace gas chromatography-ion mobility spectrometry.

Static headspace gas chromatography-ion mobility spectrometry (SHS GC-IMS) is a relatively new analytical technique that has considerable potential for analysis of volatile organic compounds (VOCs). In this study, SHS GC-IMS was used for the identification of the major terpene components of various essential oils (EOs). Based on the data obtained from 25 terpene standards and 50 EOs, a database for fingerprint identification of characteristic terpenes and EOs was generated utilizing SHS GC-IMS for authenticity testing of fragrances in foods, cosmetics, and personal care products. This database contains specific normalized IMS drift times and GC retention indices for 50 terpene components of EOs. Initially, the SHS GC-IMS parameters, e.g., drift gas and carrier gas flow rates, drift tube, and column temperatures, were evaluated to determine suitable operating conditions for terpene separation and identification. Gas chromatography-mass spectrometry (GC-MS) was used as a reference method for the identification of terpenes in EOs. The fingerprint pattern based on the normalized IMS drift times and retention indices of 50 terpenes is presented for 50 EOs. The applicability of the method was proven on examples of ten commercially available food, cosmetic, and personal care product samples. The results confirm the suitability of SHS GC-IMS as a powerful analytical technique for direct identification of terpene components in solid and liquid samples without any pretreatment. Graphical abstract Fingerprint pattern identification of terpenes and essential oils using static headspace gas chromatography-ion mobility spectrometry.

Hepatotoxicity of monoterpenes and sesquiterpenes.

Public interest in natural therapies has increased significantly over past decades. Herbs and herbal products are extensively consumed worldwide and they are generally considered as safe. However, this may not always be true as many cases of herb-induced liver injury are reported every year. The liver is a frequent target tissue of toxicity from all classes of toxicants as liver structure and function predispose it to high sensitivity to xenobiotics. The present review is focused on the hepatotoxic properties of monoterpenes and sesquiterpenes, plant secondary metabolites that represent the major components of essential oils wildly used in folk medicines, pharmaceutical industry and cosmetics. Most of these terpenes easily enter the human body by oral absorption, penetration through the skin, or inhalation leading to measurable blood concentrations. Several studies showed that some monoterpenes (e.g., pulegone, menthofuran, camphor, and limonene) and sesquiterpenes (e.g., zederone, germacrone) exhibited liver toxicity, which is mainly based on reactive metabolites formation, increased concentration of reactive oxygen species and impaired antioxidant defense. There is a high probability that many other terpenes, without sufficiently known metabolism and effects in human liver, could also exert hepatotoxicity. Especially terpenes, that are important components of essential oils with proved hepatotoxicity, should deserve more attention. Intensive research in terpenes metabolism and toxicity represent the only way to reduce the risk of liver injury induced by essential oils and other terpenes-containing products.

THE COMPONENT COMPOSITION AND FUMIGANTN ACTIVITY OF ESSENTIAL OILS OF SPECIES OF GENUS ARTEMISIA L.

The article presents data on the study of fumigantn activity of 12 species (A. fragrans Willd., A szowitziana (Bess.) Grossh., A. spicigera Koch., A. santonica L., A. kobstanica Rzazade, A. scoparia W.et. K., A. scoparioides Grossh., A. annua L., A. maritima L., A. marschalliana Spreng., A. pausiflora Web.ex Stechm., A. tournefortiana Rchb., A. hanseniana Grossh. genus Artemisia L. It is revealed repellent effects of essential oils for 3–8 hours.Duration of repellent action depends on the major component of essential oils. Maximum duration (8 hours.) was observed in action of essential oils Artemisia fragrans Willd, A.santonica, A szowitziana and A.spicigera. Duration repellent action also depends on the ambient temperature. Essential oils of the studied species are repellents and can be used in the prevention of malaria, Zeke disease and other illnesses. Repellent effect of essential oils is associated with majore various components of essential oils; A.fragrans 1,8-cineole (3,6%) and λ-thujone (28%); A.szowitziana β-thujone, 75% and λ-tuyon (9%); A. spicigera camphor (48%) and 1,8-cineole (46%); A.santonica β-citral (34%) and λ-citral (33%).

Correlation between phenological changes, chemical composition and biological activities of the essential oil from Moroccan endemic Oregano (Origanum compactum Benth)

The aims of this study were to evaluate the chemical composition, antibacterial, antioxidant and antileishmanial activities of essential oils extracted by hydrodistillation from the aerial parts of wild endemic Moroccan Origanum compactum at three phenological stages (vegetative, flowering and post-flowering). GC/MS analyses of the essential oils have revealed the presence of 37 components represented mainly by oxygenated monoterpenes (49.4–62.975%) and hydrocarbons monoterpenes (31.815–43.632%). Carvacrol, thymol, p-cymene and γ-terpinene were the major components of essential oils at three phenological stages. The antioxidant activity was estimated by DPPH free radical scavenging ability and reducing power. Essential oils obtained from post-flowering stage showed the highest antioxidant capacity with IC50 values of 172.87±5.38μg/mL and IC50=53.28±2.64μg/mL revealed by the DPPH and reducing power assay respectively. The antibacterial activity was tested against pathogenic strains using the diffusion method, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) by microtitration assay. The essential oil of vegetative and flowering stage showed remarkable antibacterial activities against Proteus mirabilis with an inhibition diameter of 43±2.12 and 47±2.73mm respectively. Moreover, the best bactericidal action was revealed by the essential oil of flowering stage against S. aureus MBLA (MIC=MBC=0.0312% (v/v)). The antiparasitic activity was tested against Leishmania major, Leishmania tropica and Leishmania infantum using MTT (3- (4.5-dimethylthiazol- 2yl) −2.5-diphenyltetrazolium bromide) assay. All essential oils showed remarkable cytotoxic activities against tested Leishmania species compared with Glucantime. The essential oil extracted at the flowering stage revealed the best antileishmanial activity. The leishmanicidal effect displayed against L. infantum was recorded at the low concentration with IC50=0.02±0.004μg/mL. The findings highlighted in this study show that flowering stage is the best optimal harvesting times of Origanum compactum for food and pharmaceutical applications.

The effect of cyclodextrin complexation on the solubility and photostability of nerolidol as pure compound and as main constituent of cabreuva essential oil.

Nerolidol (Ner), a major component of many plant essential oils, is known for its various biological properties. However, the low solubility of Ner in water and its susceptibility to degradation limit its application. The aim of our study was to improve the solubility and photostability of Ner through its encapsulation in different cyclodextrins (CDs). The formation constants of cis-, trans-Ner and their commercial mixture with various CDs (α-CD, β-CD, γ-CD, HP-β-CD, RAMEB, CRYSMEB and SBE-β-CD) were determined by phase solubility studies and confirmed by the spectral displacement UV-visible method. The solubility of cabreuva essential oil (EO) rich in trans-Ner was also evaluated by total organic carbon (TOC) analysis. The encapsulation efficiency (EE %) of Ner in HP-β-CD solid complexes was assessed by HPLC. The structural characterization of CD/trans-Ner inclusion complex was then conducted by NMR spectroscopy followed by molecular modelling studies. The effect of encapsulation on the Ner photostability was also carried out over time under UVB irradiation. AL-type phase-solubility diagrams were obtained, suggesting the formation of 1:1 CD/Ner inclusion complexes. The solubility of Ner was enhanced by approximately 70-fold in the presence of 10 mM HP-β-CD. Moreover, high EE % values were obtained for 5:1 and 10:1 HP-β-CD:Ner molar ratios. NMR and molecular modelling studies revealed the most stable structure for trans-Ner inside the CD cavity with the OH group oriented towards the wider rim of the CD. Finally, CD encapsulation of Ner as pure compound or as main component of the cabreuva EO, protected it from degradation. This effect was more pronounced as the concentration of CD increased. These findings suggested that CDs are promising encapsulating carriers for Ner by enhancing its solubility and stability and thereby its application in food industry.

Natural herbicide activity of Satureja hortensis L. essential oil nanoemulsion on the seed germination and morphophysiological features of two important weed species

The aim of the present study was to obtain an oil/water (O/W) nanoemulsion (NE) containing garden savory (Satureja hortensis) essential oil (EO) and evaluating its herbicidal activity against Amaranthus retroflexus and Chenopodium album. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) were employed to determine the chemical composition of the EO. Carvacrol (55.6%) and γ-terpinene (31.9%) were the major EO components. Low energy method was applied, allowing achievement of EO nanodroplets. The NE also presented low polydispersity, and the mean droplet was below 130nm even after storage for 30d. Laboratory tests showed that the NE at different concentrations (100, 200, 400, 800, and 1000μL.L−1) significantly (P≤0.05) reduced the germination indices and the seedling's growth in dose-response. The inhibitory effect was the greatest at 800μL.L−1 NE. Overall, root length was more inhibited as compared to shoot length. Post-emergence application of NE at different concentrations (1000, 2000, 3000, 4000 and 5000μL.L−1 of EO) on 2–4 true leaves' stage of the weeds caused significant (P≤0.05) decrease in the growth factors in dose-dependent manner. Complete lethality was observed by 4000μL.L−1 NE sprayed on the weeds. Spraying of NE significantly (P≤0.05) reduced chlorophyll content in the tested weeds. Increasing in relative electrolyte leakage (REL) 1 and 5d after treatment represented significant cell membrane disruption and increased cell membrane permeability. Transmission electron microscope (TEM) pictures confirmed NE droplet size and demonstrated membrane destruction. The study approved that the NE of S. hortensis EO has herbicidal properties as it has high phytotoxic effect, and interferes with the germination, growth and physiological processes of the weeds. The production of NE from S. hortensis EO is a low energy method that offers a promising practical natural herbicide for weed control in organic agricultural systems.

Essential Oil and Bioactive Compounds Variation in Myrtle (Myrtus communis L.) as Affected by Seasonal Variation and Salt Stress.

The effect of different NaCl concentrations (control, 2, 4 and 6dS/m) and three harvesting times in different seasons including spring (9 April), summer (5 July), and fall (23 September) was evaluated on essential oil (EO) yield, composition, phenolic, flavonoid content, and antioxidant activity of myrtle. Essential oil yield ranged from 0.2% in control and fall to 1.6% in moderate salinity (4dS/m) and spring season. The main constituents obtained from gas chromatography/mass spectrometry analysis were α-pinene, 1,8-cineole, limonene, linalool, α-terpineol, and linalyl acetate in which α-pinene ranged from 11.70% in moderate and fall to 30.99% in low salinity (2dS/m) and spring, while 1,8-cineole varied from 7.42% in high salinity (6dS/m) and summer to 15.45% in low salinity and spring, respectively. Salt stress also resulted in an increase in total phenolic, flavonoid content, and antioxidant activity. The highest antioxidant activity based on DPPH radical scavenging activity, reducing power (FTC) and β-carotene/linoleic acid model systems was found in plants harvested in spring and summer in high stress condition. The lowest IC50 values obtained in 6dS/m in spring (375.23μg/ml) followed by summer (249.41μg/ml) and fall (618.38μg/ml). Eight major phenolic and flavonoid compounds were determined in three harvesting times using high performance liquid chromatography analysis. In overall, late harvesting time of myrtle in fall can lead to reduce the most of major EO components, while it can improve the amount of phenolic acids.

Phytochemical Analysis, Antioxidant and Antibacterial Activities of Four Lamiaceae Species Cultivated in Barnyard Manure

The present study was conducted to determine essential oil yields, essential oil compositions, total phenolics, antioxidant and antibacterial activities of organic manure-treated medicinal plants of Salvia officinalis L. (sage), Lavandula angustifolia L. (lavender), Melissa officinalis L. (lemon balm) and Origanum vulgare ssp. hirtum (origano). Essential oil yields of investigated medicinal plants varied between 0.06±0.01%-3.43±0.06%. The 1,8-cineol (15.285±0.003%), viridiflorol (12.095±0.003%) and cis-thujone (12.200±0.003%) were the major essential oil components in S. officinalis L. Linalool (22.400±0.003%) 1,8-cineol (8.215±0.003%), linalyl acetate (7.900±0.003%) and lavadulyl acetate (7.690±0.003%) were the major components in L. angustifolia L. Citronellal (14.515±0.003%), geranial (13.050±0.003%) and β-caryophyllene (12.385±0.003%) were the major components in M. officinalis L. and carvacrol (65.080±0.003%) was the major component in O. vulgare ssp. hirtum. The highest total phenolics content and antioxidant activity were observed in M. officinalis. The best antibacterial activity against Staphylococcus aureus ATCC 43300, Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis ATCC 12228, Enterococcus faecalis ATCC 29212 and Escherichia coli ATCC 35218 bacteria was observed in O. vulgare ssp. hirtum.