Constituents Of Essential Oil Research Articles

Ocimum Gratissimum essential oil: A review of extraction methods, phytochemical constituents, pharmacological uses and formulation approaches

Ocimum gratissimum is a plant native to Africa. Its leaves have been used in local dishes over the years, with documented evidence of varying pharmacological uses of its essential oil. This review focuses on the extraction methods, phytochemical constituents, pharmacological uses and formulation approaches of Ocimum gratissimum essential oil. The traditional extraction methods that have been widely used include the solvent, cold press and hydrodistillation methods. However, newer methods such as steam distillation, ultrasound and microwave assisted hydrodistillation, supercritical fluid extraction, pressurized liquid extraction and pressurized hot water extraction methods have not been fully reported. These methods provide more yield of the essential oil compared with the traditional methods and their processes are less laborious. Furthermore, they are often limited to analytical applications as they cannot handle large quantities of samples. The phytochemical constituents of Ocimum gratissimum essential oil vary, based on location of the plant and the time of the season the plant parts were harvested for extraction. The African species have more thymol than eugenol. Other notable constituents are saponins, terpenes and flavonoids in both African species and others. The essential oil of Ocimum gratissimum bears the scent of the plant and other important properties such as protection of the plant from pests and to attract insects for cross-pollination. The essential oil of this plant has been noted to possess various pharmacological properties which explains its use in inflammatory conditions and the treatment of diarrhoeal disease, wound healing and cerebrovascular disorder, amongst others. The essential oil of Ocimum gratissimum has been embedded in gels, cream, silver nanoparticles and nanoemulsion to improve its pharmacological activity and bioavailability. This review article highlights the potentials of the essential oil of this ubiquitous plant as a therapeutic source for the treatment of different tropical diseases.

Efficacy of Lemon Myrtle Essential Oil as a Bio-Fungicide in Inhibiting Citrus Green Mould.

The effectiveness of lemon myrtle (LM) (Backhousia citriodora) essential oil (EO) was investigated to combat Penicillium digitatum by in vitro agar diffusion and vapour assay and in artificially infected oranges. The main constituent of LM EO was revealed as citral when analysed in gas chromatography-mass spectrometry. Pure citral was also included in the experiment for comparison. The in vitro fungal growth was significantly inhibited by LM EO at 1, 2, 3, 4 and 5 μL per disc while complete growth inhibition by both the pure citral and LM EO occurred at 4 and 5 μL per disc. Inoculated fruits treated by dipping in 1000 μL L-1 LM EO solutions for 5, 10, 15, 30 and 120 s showed significantly lower fungal wounds compared to control. While longer dipping times led to some rind injuries, fruits with a 5 and 10 s dip were found free from any injury. The evaluation after dipping and storage confirmed that the fruits maintained the sensory attributes and were not compromised by the incorporation of the essential oil. The results of this study indicate that LM EO can be a promising alternative to synthetic fungicides for preserving the quality of citrus fruits during storage.

Foliar application of salicylic acid and proline to mitigate water deficit impact on purple coneflower (Echinacea purpurea (L.) Moench.)

The effects of foliar spraying of salicylic acid and proline on Echinacea purpurea under different soil moistures were investigated in the field conditions in the Southwest of Iran (2017–2019). The experiment treatments were the foliar application of salicylic acid (SA) and proline (both at 1 mM concentration) and 2 irrigation frequencies (6 and 10 every day based on 75–80% and 40–45% field capacity, respectively). The field experiment was set as a complete randomized block design with 3 replications. The volatile oils were analyzed using GC-FID and GC-MS. Germacrene D, p-cymene, β-caryophyllene, α-pinene, and β-bisabolene were detected as the main constituents. Deficit irrigation decreased the growth parameters of the plants; however, it improved the contents of the volatile oil and the major compounds of volatile oil. In addition, the maximum values of the volatile oil content and the main constituents of volatile oil were extracted from the plants under SA × water deficit treatment. In conclusion, the foliar spraying of SA under water deficit conditions was an applicable strategy to maintain and stabilize the growth and yield of E. purpurea.

Jasmone Is a Ligand-Selective Allosteric Antagonist of Aryl Hydrocarbon Receptor (AhR).

Herbal extracts represent a wide spectrum of biologically active ingredients with potential medical applications. By screening minor constituents of jasmine essential oil towards aryl hydrocarbon receptor (AhR) activity using a gene reporter assay (GRA), we found the antagonist effects of jasmone (3-methyl-2-[(2Z)-pent-2-en-1-yl]cyclopent-2-en-1-one). It inhibited 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-, benzo[a]pyrene (BaP)-, and 6-formylindolo[3,2-b]carbazole (FICZ)-triggered AhR-dependent luciferase activity in a concentration-dependent manner. However, the inhibition differed markedly between TCDD, BaP, and FICZ, with the latter being significantly less inhibited. The dose-response analysis confirmed an allosteric type of AhR antagonism. Furthermore, jasmone efficiently inhibited AhR activation by AhR agonists and microbial catabolites of tryptophan (MICTs). TCDD- and FICZ-inducible CYP1A1 expression in primary human hepatocytes was inhibited by jasmone, whereas in the human HepG2 and LS180 cells, jasmone antagonized only TCDD-activated AhR. Jasmone only partially displaced radiolabeled TCDD from its binding to mouse Ahr, suggesting it is not a typical orthosteric ligand of AhR. TCDD-elicited AhR nuclear translocation was not affected by jasmone, whereas downstream signaling events, including the formation of the AhR:ARNT complex and enrichment of the CYP1A1 promoter, were inhibited by jasmone. In conclusion, we show that jasmone is a potent allosteric antagonist of AhR. Such discovery may help to find and/or clarify the use of jasmone in pharmaco- and phytotherapy for conditions where AhR plays a key role.

Exogenous melatonin differentially affects biomass, total carbohydrates, and essential oil production in peppermint upon simultaneous exposure to chitosan-coated Fe3O4 NPs

Melatonin and iron play important roles in the growth processes and production of secondary metabolites in medicinal plants. To evaluate the effects of melatonin and Chitosan-Coated Iron Oxide Nanoparticles (Fe-CTs NPs) on peppermint growth, essential oil content and constituents, total carbohydrates and antioxidant enzyme activities, a factorial experiment was conducted based on randomized complete block design (CRBD) with three replications (n = 3). Treatments consisted of different concentrations of melatonin (0, 100, and 200 mg L−1) and Fe-CTs NPs (0, 7.5, and 15 mg L−1). During the experiment, foliar applications of melatonin and Fe-CTs NPs were performed three times with 20 days’ interval. Treatments with melatonin, and Fe-CTs NPs had significant effects on the studied traits. The results showed that with increasing melatonin and Fe-CTs NPs concentrations, fresh and dry weights, total carbohydrates, and leaf area index were significantly (P < 0.05) increased in treated plants. The highest CAT and APX activities were observed in plants treated with melatonin at 100 mg L−1 and Fe-CTs NPs at 15 mg L−1. Eucalyptol, Menthyl acetate, Thiophene, 2-ethyl-5-(2-methylpropyl), Mint furanone, and Viridiflorol were found as the major essential oil constituents in peppermint plants under experimental treatments. Moreover, analytical results showed that the highest amount of Menthol (38.48 %) was obtained in plants exposed to Fe-CTs NPs at 7.5 mg L−1, however, the highest L-Menthone (30.53 %) was observed in plants treated with melatonin at 200 mg L−1 and Fe-CTs NPs at 15 mg L−1. The findings provide insights into the regulatory mechanisms of melatonin and Fe-CTs NPs on peppermint growth, physiology and biosynthesis of volatile compounds.

Exogenous Putrescine Changes Biochemical (Antioxidant Activity, Polyphenol, Flavonoid, and Total Phenol Compounds) and Essential Oil Constituents of Salvia officinalis L.

Polyamines are small polycationic molecules containing amines that are present in almost all cells of living organisms and act in a wide range of physiological processes, growth, and development, biological and protection of cells against free radicals. This research is based on principal component analysis (PCA) and calculation of selection criteria (SC) to investigate the effect of foliar spraying of polyamine putrescine on essential oil yield, essential oil compounds, antioxidant activity, and biochemical compounds (polyphenol, flavonoid, and total phenol compounds) of Salvia officinalis. The treatments used included four levels of putrescine, Put (Control: 0, Put1: 500, Put2: 1000, and Put3: 1500 mg L-1 ) with five replications. Based on our results, four factors had eigenvalues≥1 and showed a cumulative variance percentage of 92.57 % by applying different concentrations of putrescine. According to the results of this research, putrescine had significant effects on the amount of total phenolic compounds, flavonoids, and antioxidant activity. The best attention to improving the essential oil yield of sage was 1000 mg L-1 . The crucial essential oil compounds of different Put treated sage were: cis-thujone (35.34 %), camphor (15.60 %), trans-thujone (9.90 %), 1,8-cineole (9.46 %), α-humulene (3.85 %), viridiflorol (3.62 %), camphene (3.58 %), α-pinene (3.50 %), β-pinene (2.78 %), and limonene (1.23 %). The results showed that the amount of total phenol, the phenolic composition of catechin, and the antioxidant activity of sage plant extract increased significantly when putrescine was used at 1000 mg/liter. Results can use the current research to optimize the production management of medicinal plants and improve the quality of their products. In addition, the advantage of using putrescine is that it increases antioxidants and reduces oxidative damage, and can replace medicinal plants as suitable natural preservatives, thus improving food quality and safety.

Electrochemical sensing of monoterpene phenols in plant essential oils using a molecularly imprinted polymer dual-template sensor

Monoterpene phenols are naturally occurring aromatic compounds found in plant essential oils, contributing to their distinct flavors, fragrances, and medicinal properties. Thymol and carvacrol, major constituents of thyme and oregano essential oils, have garnered significant attention due to their diverse biological activities. Here, we propose the development of a novel double template molecular imprinted electrochemical sensor (DT-MIP sensor) for the selective and simultaneous detection of thymol and carvacrol. The sensor's performance was optimized by varying the quantity of functional monomer, cross-linker, and template molecules during MIP synthesis. The DT-MIP sensor demonstrated superior recognition properties and high sensitivity, with detection limits of 0.11 μM for carvacrol and 0.24 μM for thymol. Selectivity tests confirmed minimal interference from potential interfering agents. GC-MS analysis validated the sensor's accuracy in detecting thymol and carvacrol concentrations in thyme and oregano essential oils. The simplicity, cost-effectiveness, and portability of the DT-MIP sensor offer promising applications in food quality control, environmental monitoring, and medical diagnostics.

New esters from the essential oil of dry flowers of elder (Sambucus nigra L.).

Elder (Sambucus nigra L.) has relevance for the food, fragrance and pharmaceutical industries. Flowers of this species emit a very pleasant scent; for processing purposes, inflorescences are either collected from the wild or harvested from a cultivated crop. The study of elderflower-derived volatiles bears both phytochemical and commercial importance. Three samples of dry elderflower essential oil obtained from laboratory-scale hydrodistillations were analyzed. By use of gas chromatography-mass spectrometry, synthesis and NMR studies of chromatographic fractions of a distillation water extract prepared in a semi-industrial scale steam distillation, 252 constituents of the oil were identified; 115 compounds were not previously reported as elderflower volatiles, seven of which were new natural esters. Particularly interesting were those of isosenecioic (3-methylbut-3-enoic) acid because these were never before found in the plant kingdom. With these identifications, the known essential oil constituents accounted for 89.0-93.0% of the analyzed samples. Although the number of known S. nigra flower-derived volatiles is now quite high, further research (both analytical and olfactory) is needed to unveil all of the relevant contributions to the unique odor of elderflowers. © 2023 Society of Chemical Industry.

Chemical Characterization and Chemotaxonomic Significance of Essential Oil Constituents of Matricaria aurea Grown in Two Different Agro-Climatic Conditions.

A comprehensive study on chemical characterization of essential oil (EO) constituents of a rarely explored plant species (Matricaria aurea) of the Asteraceae family grown in Saudi Arabia and Jordan was carried out. Analyses were conducted employing gas chromatographic approaches such as GC-MS, GC-FID, and Co-GC, as well as RT, LRI determination, and database and literature comparisons, on two diverse stationary phase columns, which led to the identification of a total of 135 constituents from both EOs. Oxygenated sesquiterpenes were found to be the most predominant chemical class of Saudi M. aurea EOs, in which α-bisabolol (27.8%), γ-gurjunenepoxide (21.7%), (E, E)-α-farnesene (16.3%), and cis-spiroether (7.5%) were present as major components. In contrast, the most dominant chemical class of Jordanian M. aurea oil was found to be sesquiterpene hydrocarbons, where (E, E)-α-farnesene (50.2%), γ-gurjunenepoxide (8.5%), (E)-β-farnesene (8.1%), and (Z, E)-α-farnesene (4.4%) were detected as chief constituents. It is interesting to mention here that Saudi and Jordanian M. aurea EOs showed quite interesting chemical compositions and were found to have different chemotypes when compared to previously reported M. aurea EO compositions.

Biological evaluation, GC–MS profiling, and molecular docking studies of some essential oils against postharvest pathogens of maize

Considering the use of essential oils (EOs) as biopesticides due to their ability to effectively control postharvest pathogens, EOs-based formulations, and coatings became a priority. The present work aimed to screen essential oils from eight different plant species with anti-fungal properties along with the phytochemical analysis and molecular docking insight. Furthermore, the selected essential oil was applied as an edible coating to examine its protective effect against the attack of isolated postharvest pathogens on maize seedlings and rescue the seedling’s growth. Eight EOs were screened for their antimicrobial potential against Fusarium oxysporum and Xanthomonas campestris. Later on, the identification of the chemical constituents of the best-performing essential oil (Bergamot oil) was performed by GC–MS analysis. Different coating formulations consisting of essential oils and chitosan at 0.25% and 0.5% concentrations were applied to maize seeds to protect against postharvest pathogens. Formulation containing the bergamot essential oil showed the highest protective potential against a fungal and bacterial postharvest pathogen of maize under in-vitro conditions. The molecular docking study showed that the linalool and linalyl acetate present in essential oil comprises strong interactions with antifungal target proteins.

Full-scale determination of essential oil diffusion: Impact on indoor air quality

Essential oils have attracted increasing interest, as they inhibit the metabolic functions of microorganisms. Essential oils are claimed to improve indoor air quality through passive remediation and purifying activities. However, the impact of diffused essential oils on indoor air quality has not been clearly established from a VOC point of view. This study aims to assess the emissions produced by terpene molecules in tea tree essential oil by employing two types of widespread diffusers under real conditions using a full-scale experimental room (40 m3). The emissions generated by terpenoid volatile organic compounds (TerVOCs) are different depending on the type of diffuser. The relative contributions of individual terpenes in the gas phase vary throughout the diffusion process. The impact of tea tree essential oil diffusion on indoor air quality varies from 6 h to 51 days, depending on the diffusion device. Concentration levels can exceed European recommended exposure levels by more than one order of magnitude. Interestingly, the volume of the emission chamber directly impacts the emission dynamics of essential oil constituents. Small chambers may limit the volume of air to be contaminated and possibly impacts the magnitude of concentration gradients during diffusion. This work evidences the interest of using full-scale experimental facilities to determine accurate emission rates. A full-scale experimental methodology including data treatment is validated in this work. Through the proposed protocol, representative emission factors can be determined to assess exposure and perform indoor air modelling.

Comparative Studies of Essential Oil Composition and Biological Activities of Callistemon citrinus from Western Himalaya.

This work described a comprehensive study to estimate chemical constituents of essential oils (EOs) extracted from different parts of the Callistemon citrinus viz: fruits, leaves and aerial part. The EOs were characterized using physicochemical parameters, and GC-FID/MS. It was observed that among different parts, aerial part has the highest oil yield (0.90 %) followed by leaves and fruits. Further, seventeen compounds were characterized, and represented total amount (97.2-99.5 %) with domination of monoterpenes (12.5-34.6 %) and oxygenated monoterpenes hydrocarbon (61.8-86.8 %). α-pinene (11.8-24.7 %), α-phellandrene (1.2-3.0 %), p-cymene (3.3-3.9 %) and 1,8-cineole (58.3-85.1 %) were found as major compounds in C. citrinus samples. These major compounds are the quality chemical markers of C. citrinus oil. The findings revealed significant quantitative variations in EO composition of samples and were also clearly supported by multivariate statistical analysis. Moreover, EOs were evaluated for glucosidase and colon cancer cell lines inhibitory activities, which were found promising.

Cyanobacterial elicitors as efficient plant growth promoters affect the biomass and metabolic profiles of four species of Mentha L.: A comparative study

Medicinal and aromatic plants contain compounds with industrial and therapeutic applications; among which genus Mentha L. has special economic importance. The present investigation aimed to evaluate the ability of cyanobacterial strains as bio-elicitors on biomass production, as well as the quality and quantity of essential oils of four species of Mentha (M. spicata L., M. piperita L., M. aquatica L., and M. pulegium L.). Following the seedling growth test, two cyanobacterial strains, Wollea vaginicola ISB89 and Nostoc spongiaeforme var. tenue ISB91, were selected as potential bio-elicitors. Then, the growth of plants under 1% cyanobacterial suspensions was assessed by measuring growth factors including length and weight of plants, and leaf area after 90 days of planting. Moreover, the amount of essential oils of plants and their constituents were evaluated. According to the results, both cyanobacterial elicitors significantly increased plant biomasses and essential oils yield. There was a direct relationship between cyanobacterial auxins and biomass and essential oil of Mentha spp.; in this way, Wollea with a higher level of auxins and cations provides essential elements for plants. Therefore, plants treated with Wollea exhibited more growth and essential oil promoting features compared to Nostoc treatments. The most important terpenoids in essential oils of investigated species belong to oxygenated monoterpenes with 79–91% contents; including Piperitenone, Menthol, and Menthone. In M. piperita, the amount of Menthone, as one of the principal constituents of essential oil, increased under cyanobacterial elicitors (115–137%). For M. spicata the enhancement of Piperitenone (46–96%), and for M. pulegium, the increase of neo-Menthol (17–115%) was remarkable. Based on the results, two cyanobacteria strains are considered as a rich source of natural compounds and phytohormones which can be used to increase the yield and essential oil production of studied economically important plant species.

Antifungal Potential and Chemical Composition of Chamaecyparis formosensis and Chamaecyparis obtusa var. formosana Essential Oils in Liquid and Vapor Phases Against 4 Fungal Species

Background Only a few studies have investigated the bioactivity of the essential oils (EOs) of Chamaecyparis formosensis and C. obtusa var. formosana, which are endemic to Taiwan. The wood and leaf EOs extracted from C. obtusa var. formosana had anti-inflammatory and antitermitic effects, respectively, and the twig EO extracted from C. formosensis inhibited the growth of Fusarium oxysporum, Pestalotiopsis funerea, and Ganoderma australe. Methods A poisoned food technique was used to evaluate the antifungal effects of wood and leaf EOs extracted from C. formosensis and C. obtusa var. formosana on brown rot fungus, white rot fungus, and mold. A phytatray chamber assay was conducted to investigate the antifungal activities of the EOs in the vapor phase. Gas chromatography-mass spectrometry was used to examine the chemical constituents of both EOs. Results The leaf EO extracted from C. formosensis primarily contained monoterpene hydrocarbons, whereas the leaf EO extracted from C. obtusa var. formosana primarily contained monoterpene and sesquiterpene hydrocarbons. The wood EOs extracted from C. formosensis and C. obtusa var. formosana primarily contained sesquiterpene hydrocarbons and oxygenated sesquiterpenes. These results indicated that the wood EOs had higher antifungal activity in the liquid phase, whereas the leaf EOs had higher antifungal activity in the vapor phase. Conclusion Wood EOs extracted from C. formosensis and C. obtusa var. formosana have strong antifungal effects against Gloeophyllum trabeum, Lenzites betulina, Trametes versicolor, and Trichoderma sp. Compared with wood EOs, leaf EOs have a greater inhibitory effect on mycelial growth in the vapor phase. In both the liquid and vapor phases, the EOs extracted from C. formosensis and C. obtusa var. formosana serve as effective antifungal agents against pathogenic fungi. Further research is required to elucidate the mechanisms underlying the antifungal activities of EOs in different phases and explore their potential applications.

Hepatoprotective effects of linalool against liver ischemia-reperfusion: the role of Nrf2/HO-1/NQO1 and TLR4/RAGE/NFκB pathways.

Hepatic ischemia-reperfusion (H I/R) injury arises due to a temporary obstruction followed by the re-establishment of blood supply to the liver. Linalool (LIN), a main volatile constituent of essential oils in numerous aromatic plant species, exhibited various medicinal and pharmacological actions. This study investigated the protective effect of LIN on the status of H I/R, with the study of the possible mechanisms. In addition, linalool's antagonistic effects were tested against several metabolic targets using in silico molecular docking technique. Wistar rats were allocated into five groups. Sham and LIN + Sham groups in which animals were administered either vehicle (1% CMC) or LIN (200 mg/kg/day) orally for two weeks. H I/R group in which rats were administered 1% CMC for two weeks and then experienced hepatic ischemia for 60 min followed by 6 hours of reperfusion. LIN 100 + H I/R and LIN 200 + H I/R groups in which rats were pretreated with LIN (100, 200 mg/kg/day) respectively for two weeks, then subjected to H I/R. H I/R-induced injury resulted in impaired liver function and activated Keap1/Nrf2/HO-1/NQO1 and HMGB1/TLR4/RAGE/NFкB pathways with subsequent oxidative stress, inflammation, and apoptosis. LIN pretreatment alleviated I/R-induced impairment in liver function, promoted Keap1/Nrf2/HO-1/NQO1, and mitigated the HMGB1/TLR4/RAGE/NFкB pathway. LIN pre-administration deterred adhesion molecule, neutrophils infiltration, RAGE, IL-1β, IL-6, TNF-α, and apoptosis. LIN demonstrated hepato-protective effects against H I/R via instigation Keap1/Nrf2/HO-1/NQO1 and mitigating the HMGB1/TLR4/RAGE/NFкB pathways with subsequent deterring oxidative stress, inflammation, and apoptosis.

Physio-morphological trait and bioactive constituents of Ocimum species under drought stress

The genus Ocimum, which belongs to the Lamiaceae family, encompasses a wide variety of herbs and shrubs, with over 60 species originating from tropical regions. These plants are widely cultivated for their essential oils, which are used in culinary, medicinal, and aromatic applications. However, prolonged exposure to water scarcity can negatively impact the growth and essential oil production of Ocimum species. There is limited information available on how Ocimum basilicum ‘Ohře’ and O. americanum respond to drought stress. Consequently, two-year studies (2021 and 2022) were conducted to investigate the physiological, morphological, and biochemical changes occurring in those two basil plants under three different soil water regimes (70%, 50%, and 30% of soil water capacities ‘SWC’). The findings of these studies demonstrated that drought stress significantly affected physiological indicators, hindered the growth and development of the examined Ocimum species, and altered their essential oil production. Due to severe drought stress both basil plants lost over 14% of their leaf relative water content and more than 60% reduction in water potential. Consequently, basil plants lost over 45% of their biomass (dry and fresh) and essential oil yield when the soil became drier (30% SWC). Conversely, dry soil conditions enhanced water use efficiency, SPAD value, glandular hair density (increased by over 60%), essential oil concentration (increased by 10%), and phenol concentration. Additionally, the essential oil constituents were mildly affected, with the effects dependent on factors such as species, production year, drought intensity, and specific essential oil compounds. In conclusion, these studies have demonstrated that prolonged exposure to water scarcity limits growth and alters the biochemical constituents of both Ocimum species. Therefore, to secure maximum biomass and essential oil yield under protected cultivation, it is recommended to maintain at least 70% soil water capacity.

Exploring the potential of 1,8-cineole from cardamom oil against food-borne pathogens: Antibacterial mechanisms and its application in meat preservation

Food-borne pathogenic bacteria are a major public health concern globally. Traditional control methods using antibiotics have limitations, leading to the exploration of alternative strategies. Essential oils such as cardamom possess antimicrobial properties and have shown efficacy against food-borne pathogenic bacteria. The utilization of essential oils and their bioactive constituents in food preservation is a viable strategy to prolong the shelf-life of food products while ensuring their quality and safety. To the best of our knowledge, there are no studies that have utilized 1,8-cineole (the main active constituent of cardamom essential oil) as a preservative in meat, so this study might be the first to utilize 1,8-cineole as an antibacterial agent in meat preservation. The application of 1,8-cineole had a significant suppressive impact on the growth rate of Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella Typhimurium in meat samples stored for 7 days at 4 °C. Additionally, the surface color of the meat samples was not negatively impacted by the application of 1,8-cineole. The minimum inhibitory concentration was 12.5–25 mg/ml, and the minimum bactericidal concentration was 25–50.0 mg/ml. The bacterial cell membrane may be the target of cardamom, causing leakage of intracellular proteins, ATP, and DNA. The obtained data in this study may pave a new avenue for using 1,8-cineole as a new perspective for dealing with this problem of food-borne pathogens and food preservation, such as meat.

Floral biology insights into essential oil yield and chemical composition in davana (Artemisia pallens Bess), a high-value aromatic plant of India

Floral organs are identified as the major source of essential oil production in some prime aromatic plants. The quality and quantity of the essential oil are also influenced by the floral developmental stages. The present study was undertaken in A. pallens Bess (davana) with respect to its floral biology and floral sequence in relation to the essential oil yield and its chemical constituents for industrial extraction. The findings revealed that floral (inflorescence) biomass is the primary source of essential oil yield in davana, with the highest oil yield (0.90 ml/100 g) recovered during the blooming stage, followed by herbage (stems and leaves) biomass. Furthermore, cis-davanone, the major chemical constituent of davana essential oil, was recorded at a higher percentage in the bud stage (66.36±0.60%) followed by the blooming stage (60.56±0.20%) and the seed setting stage (40.54±0.80%). These findings can be used to optimize harvest timing in order to obtain higher quality and quantity of davana essential oil.

Siparuna guianensis Essential Oil Antitumoral Activity on Ehrlich Model and Its Effect on Oxidative Stress.

This work aims to evaluate the chemical composition, in vitro antioxidant capacity, and in vivo antitumoral activity of S. guianensis essential oil against Ehrlich's ascitic carcinoma and the effects on oxidative stress. The animals (Mus musculus) received a daily dose of S. guianensis oil orally (100 mg/kg) for 9 days. The main constituents of essential oil were curzerenone (16.4±1.5 %), drimenol (13.7±0.2 %), and spathulenol (12.4±0.8 %). S. guianensis oil showed antioxidant activity, inhibiting 11.1 % of DPPH radicals (95.7 mgTE/g); and 15.5 % of the β-carotene peroxidation. The group treated with S. guianensis showed a significant reduction in tumor cells (59.76±12.33) compared to the tumor group (96.88±19.15). Essential oil of S. guianensis decreased MDA levels and increased SOD levels in liver tissue. The essential oil of S. guianensis reduced oxidative stress, and showed antitumor and antioxidant activity, being characterized as a new chemical profile in the investigation of pathologies such as cancer.

Furanonaphthoquinones, Diterpenes, and Flavonoids from Sweet Marjoram and Investigation of Antimicrobial, Bacterial Efflux, and Biofilm Formation Inhibitory Activities.

The chloroform extract of Origanum majorana exhibited high antibacterial and antifungal activities against 12 bacterial and 4 fungal strains; therefore, it was subjected to bioassay-guided isolation to afford six compounds (1-6). The structures were determined via one- and two-dimensional nuclear magnetic spectroscopy and high-resolution electrospray ionization mass spectrometry experiments. The compounds were identified as furanonaphthoquinones [majoranaquinone (1), 2,3-dimethylnaphtho[2,3-b]furan-4,9-dione (2)], diterpenes [19-hydroxyabieta-8,11,13-trien-7-one (3), 13,14-seco-13-oxo-19-hydroxyabieta-8-en-14-al (4)], and flavonoids [sterubin (5) and majoranin (6)]. Compounds 1 and 2 were first obtained from a natural source and compounds 3 and 4 were previously undescribed. Majoranaquinone (1) exhibited a high antibacterial effect against 4 Staphylococcus, 1 Moraxella, and 1 Enterococcus strains (MIC values between 7.8 μM and 1 mM). In the efflux pump inhibition assay, majoranaquinone (1) showed substantial activity in Escherichia coli ATCC 25922 strain. Furthermore, 1 was found to be an effective biofilm formation inhibitor on E. coli ATCC 25922 and E. coli K-12 AG100 bacteria. Our findings proved that bioactivities of majoranaquinone (1) significantly exceed those of the essential oil constituents; therefore, it should also be considered when assessing the antimicrobial effects of O. majorana.