Major Components Of Essential Oil Research Articles

Chemical Composition and Biological Evaluation of Typha domingensis Pers. to Ameliorate Health Pathologies: In Vitro and In Silico Approaches.

Human diseases are becoming more prevalent, necessitating the development of modalities to overcome the challenges of treating various disorders. In the current research, we analyzed the biomedicinal role of Typha domingensis which is an important medicinal plant. The species is traditionally used in the treatment of neurological disorders and skin malignancies. The chloroform (CFTD) and n-butanol fractions of T. domingensis (BFTD) were subjected to chemical profiling through the determination of total polyphenolic contents and GC-MS analysis. The oral toxicity test was applied to investigate the toxicity of the extracts. Antioxidant capacity was analyzed by four in vitro methods: DPPH, ABTS, FRAP, and CUPRAC. The pharmacological potential was evaluated through clinically significant enzyme inhibition assays, thrombolytic, and antimicrobial activities. In silico molecular docking approach was applied to confirm the role of T. domingensis against the enzymes. The polyphenolic quantification revealed that the BFTD was comparatively rich in total phenolic and flavonoid contents (97.14 milligrams gallic acid equivalent (mg GAE/g) and 362.5 milligrams quercetin equivalent per gram of dry extract (mg QE/g DE), respectively), as compared to the CFTD. The GC-MS analysis of the CFTD and BFTD resulted in the tentative identification of 67 and 29 compounds, respectively, with the major components of fatty acids and essential oil. The oral toxicity test revealed the safety and biocompatibility of CFTD and BFTD. Both the fractions showed promising antioxidant activity. Tyrosinase was found as the major enzyme inhibited by BFTD (78.67%) and CFTD (68.09%), whereas the standard kojic acid showed 85.58% inhibition. The inhibition results of acetylcholinesterase and butyrylcholinesterase by BFTD (71.65 and 60.79%, respectively) are higher than CFTD. Both the fractions were found active against various strains of bacteria. Furthermore, the molecular docking studies of the compounds showed a good docking score against all the docked enzymes among which deoxycaesaldekarin C was found with the highest binding affinities in comparison to the standard. The current study suggests that T. domingensis is nontoxic and can be a potential source of phytoconstituents with promising pharmacological potential.

The effect of pectinase pretreatment on the extraction of essential oil from the seed kernels of Nutmeg (Myristica fragrans)

In this study, the seed kernels of Nutmeg (Myristica fragrans) were pretreated with partially purified pectinase (PPP) prior to hydrodistillation to enhance the extraction of essential oil. The yield of the essential oil obtained after pretreatment with PPP was 4.70%. GC-MS analysis of the essential oils obtained after pretreatments with PPP showed a total of 33 constituents classified into monoterpenes (51.52%), sesquiterpenes (21.21%) and phenylpropanoids/aromatic (27.27%) compounds. Comparison was made by pretreating the nutmeg seeds with a pure pectinase (CP) obtained from Sigma-Aldrich. The fraction obtained when pretreated with CP was made up of 32 components with monoterpenes (51.31%), sesquiterpenes (18.75%) and phenylpropanoids/aromatic (28.12%) compounds. The major components of essential oils obtained after pretreatments with PPP and CP were sabinene, α-pinene, β-pinene and myristicin. This research shows that the extraction of Myristica fragrans seed kernel essential oil can be improved using PPP when compared with the yield of the control (3.80%) obtained from the seed kernels that were not pretreated with the enzymes prior to hydrodistillation.

Plant elicitation and TiO2 nanoparticles application as an effective strategy for improving the growth, biochemical properties, and essential oil of peppermint.

MenthapiperitaL., which is an abundant source of essential oils (EO) and phenolic acids, is well known for its medicinal significance. The present research aimed to evaluate the impact of various concentrations of methyl jasmonate (MeJA; 0, 0.1, and 0.5mM), titanium dioxide nanoparticles (TiO2 NPs; 0 and 150mg L-1), and salicylic acid (SA; 0, 0.1, and 1mM) on growth, EOs, and phenolic compounds ofM.piperitaL. The results demonstrated that the simultaneous application of SA (0.1mM) and TiO2 NPs (150mg L-1) enhanced shoot dry weight, the shoot length, and membrane stability index of peppermint by 56.17, 19.52, and 36%, respectively, compared to control. Moreover, phenolic content (76%), caffeic acid content (78%), rosmarinic acid content (87%), 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability (78%), and catalase (155%), ascorbate peroxidase activities (95%) were further improved by simultaneously applying MeJA (0.1mM) and TiO2 NPs (150mg L-1) compared to control. The highest menthol production (44.51%) was obtained with exogenous application of MeJA (0.1mM) with 150mg L-1 TiO2 NPs. The findings of the current study presented an ideal combination of TiO2 NPs with plant growth regulators for promoting antioxidant activities and increasing major components of EO in peppermint plants.

Establishing Komagataella phaffii as a Cell Factory for Efficient Production of Sesquiterpenoid α-Santalene.

Santalene, a major component of the sandalwood essential oil, is a typical representative of sesquiterpenes and has important applications in medicine, food, flavors, and other fields. Due to the limited supply of natural sandalwood resources, there is a growing interest in engineering microbial cell factories for the mass production of santalene. In the present study, Komagataella phaffii (also known as Pichia pastoris) was established as a cell factory for high-level production of α-santalene for the first time. The metabolic fluxes were rewired toward α-santalene biosynthesis through the optimization of promoters to drive the expression of the α-santalene synthase (SAS) gene, overexpression of the key mevalonate pathway genes (i.e., tHMG1, IDI1, and ERG20), and multi-copy integration of the SAS expression cassette. In combination with medium optimization and bioprocess engineering, the optimal strain (STE-9) was able to produce α-santalene with a titer as high as 829.8 ± 70.6 mg/L, 4.4 ± 0.3 g/L, and 21.5 ± 1.6 g/L in a shake flask, batch fermenter, and fed-batch fermenter, respectively. These represented the highest production of α-santalene ever reported, highlighting the advantages of K. phaffii cell factories for the production of terpenoids and other natural products.

Improved yields and essential oil composition of ajowan (Trachyspermum ammi L.) and soil fertility properties in intercropping systems

ABSTRACT Legume-based intercropping systems have been proposed as sustainable and eco-friendly systems with potential to improve crop production and soil fertility. A field experiment was conducted in two growing seasons (2017 and 2018) to determine optimal intercropping patterns of ajowan (Trachyspermum ammi L.) and fenugreek (Trigonella foenum-graecum L.) to increase yield and quality of the ajowan and to improve soil properties. The treatments evaluated in this study were sole cropping of ajowan (A) and fenugreek (F), replacement intercropping series of A:F (1:1, 4:4, 3:1, and 1:3 ratios) and additive intercropping series of A:F (100:12.5, 100:25, 100:37.5, 100:50, 100:62.5, 100:75, and 100:87.5 ratios). The results showed that the highest biological yield (4172.7 kg ha−1), seed yield (1009.7 kg ha−1), and essential oil yield (42.0 kg ha−1) of ajowan were obtained in the additive pattern A:F 100:25. The highest concentrations of thymol and γ-terpinene, the major chemical components of ajowan essential oil, were recorded for the A:F 100:25 intercropping pattern. Total LER and ATER indices were above one in all of the intercropping patterns. The concentrations of soil total organic carbon (TOC) and nitrogen (TON), available forms of NO3 − and NH4 +, Mg2+, K+, as well as basal respiration (BR) and substrate-induced respiration (SIR) in the A:F 100:25 intercropping pattern were greater than for the fenugreek and ajowan sole crops. Overall, the analysis showed that the A:F 100:25 additive intercropping pattern had positive and strong effects in terms of increased yield and quality of ajowan and improvement of soil fertility.

Dose differentiation in elevated UV-B manifests variable response of carbon-nitrogen content with changes in secondary metabolites of Curcuma caesia Roxb.

Despite acting as environmental stress, UV-B also plays a regulatory role in the plant's growth and secondary metabolism. UV-B-induced changes show variations between and among the species. The present study mainly focuses on variations in carbon and nitrogen contents and their relation with the phytochemical constituents of Curcuma caesia exposed to two different doses of UV-B (ambient ± elevated UV-B for 1h (2.4kJm-2day-1) and 2h (4.8kJm-2day-1)) under natural field conditions. Results showed that increasing the dose of eUV-B leads to high tuber biomass and reduced rhizome biomass (the medicinally important part). Increased expression of compounds at the initial rhizome formation stage might be due to the increased carbon content, whereas no such trend was found at the final growth or rhizome maturation stage. After final harvesting, carbon content was reduced, with an increase of nitrogen content which might be responsible for enhanced production of major components of essential oil (D-camphor and 1,8-cineole) in 2h of UV-B exposure followed by 1h. The phytochemical analysis at the final stage showed induction of compounds (15 and 10 in 1h and 2h, respectively) after UV-B exposure which was not detected in controls. The present study suggests that the change in carbon-nitrogen played an important role in the fraction of compounds at different stages, and a lower dose of UV-B (1h) favoured the increased production of essential oil; however, 2h dose is important for the enhanced production of major active compounds of essential oil.

Untargeted Metabolomics Approach of Cross-Adaptation in Salmonella Enterica Induced by Major Compounds of Essential Oils.

Cross-adaptation phenomena in bacterial populations, induced by sublethal doses of antibacterial solutions, are a major problem in the field of food safety. In this regard, essential oils and their major compounds appear as an effective alternative to common sanitizers in food industry environments. The present study aimed to evaluate the untargeted metabolomics perturbations of Salmonella enterica serovar Enteritidis that has been previously exposed to the sublethal doses of the major components of essential oils: cinnamaldehyde, citral, and linalool (CIN, CIT, and LIN, respectively). Cinnamaldehyde appeared to be the most efficient compound in the assays evaluating the inhibitory effects [0.06% (v/v) as MBC]. Also, preliminary tests exhibited a phenotype of adaptation in planktonic and sessile cells of S. Enteritidis when exposed to sublethal doses of linalool, resulting in tolerance to previously lethal concentrations of citral. A metabolomics approach on S. Enteritidis provided an important insight into the phenomenon of cross-adaptation induced by sublethal doses of major compounds of some essential oils. In addition, according to the results obtained, when single molecules were used, many pathways may be involved in bacterial tolerance, which could be different from the findings revealed in previous studies regarding the use of phytocomplex of essential oils. Orthogonal projection to latent structures (OPLS) proved to be an interesting predictive model to demonstrate the adaptation events in pathogenic bacteria because of the global engagement to prevent and control foodborne outbreaks.

Essential Oil Content and Compositional Variability of Lavandula Species Cultivated in the Mid Hill Conditions of the Western Himalaya.

The increase in the utilization of Lavandula essential oil in industries led to an impressive rise in the demand for quality essential oils. However, a post-harvest drying of Lavandula species can be a decisive factor to determine the quantity and quality of essential oil. The study was conducted in western Himalayan conditions to assess the essential oil content and composition of two Lavandula species viz., lavender (Lavandula angustifolia Mill.), and lavandin (Lavandula × intermedia Emeric ex Loisel), at four different drying duration (0 h, 24 h, 48 h and 72 h after the harvest). The higher growth attributes viz., plant height (71.7 cm), ear length (8.8 cm), number of spikes (18.1), and number of flowers per ear (47.5) were higher in lavandin, while the number of branches (17.1) was higher in lavender. Essential oil content (%) and moisture reduction (%) were significantly higher at 72 h than at 0 h. The major components of lavender and lavandin essential oil were linalool (33.6–40.5%), linalyl acetate (10.8–13.6%), lavandulyl acetate (2.8–14.5%), and linalyl propionate (5.3–14.1%) in both the Lavandula species. There was a decreasing trend in linalool and an increasing trend in linalyl acetate content in lavandin, with an increase in drying duration up to 72 h; while in lavender, no regular trend was observed in linalool and linalyl acetate content. It was observed that linalool and linalyl acetate levels were the highest at 24 and 0 h of drying in lavender and lavandin, respectively, and essential oil extraction can be done according to the desire of the constituent at varied drying duration.

Selenium Nanoparticles (Se-NPs) Alleviates Salinity Damages and Improves Phytochemical Characteristics of Pineapple Mint (Mentha suaveolens Ehrh.).

The present study examined the effects of foliar spray of selenium nanoparticles (0, 10 and 20 mg/L) on the yield, phytochemicals and essential oil content and composition of pineapple mint (Mentha suaveolens Ehrh.) under salinity stress (0, 30, 60 and 90 mM NaCl). Obtained results demonstrated that severe salinity stress reduced the fresh weight (FW) and plant height (PH) by 16.40% and 19.10%, respectively compared with normal growth condition. On the other hands, under sever salinity stress relative water content (RWC) and chlorophyll index were reduced by 18.05% and 3.50%, respectively. Interestingly, selenium nanoparticles (Se-NPs; 10 mg/L) application improved the pineapple mint growth. Based on GC-FID and GC-MS analysis, 19 compounds were identified in pineapple mint essential oil. Foliar application of Se-NPs and salinity did not change the essential oil content of pineapple mint, however, the essential oil compounds were significantly affected by salinity and Se-NPs- applications. Foliar application of Se-NPs- had a significant effect on piperitenone oxide, limonene, jasmone, viridiflorol and β-myrsene under different salinity levels. The highest percentage of piperitenone oxide (79.4%) as the major essential oil component was recorded in the no salinity treatment by applying 10 mg/L of nanoparticle. Interestingly, application of 10 mg L−1 Se-NPs- under 60 mM NaCl increased the piperitenone oxide content by 9.1% compared with non-sprayed plants. Finally, the obtained results demonstrated that foliar application of Se-NPs (10 mg L−1) can improve the pineapple mint growth and secondary metabolites profile under saline conditions.

Metal-organic framework on porous TiO2 thin film-coated alumina beads for fractional distillation of plant essential oils.

Fractionation of essential oils is technically challenging due to enormous scaffold diversities and structural complexities as well as difficulties in the implementation of the fractionation in the gas phase. Packing beads with multi-dimensional hierarchical nanostructures have been developed herein to pack fractional columns for atmospheric distillations. Activated alumina beads were coated with a porous TiO2 thin film. Growth of Cu-BTC (benzene-1,3,5-tricarboxylate) crystals in resultant porous surfaces leads to the generation of new nanopores and increased metal centers for differential coordination with diverse components of essential oils. The TiO2 thin film is not only an integral part of the composites but also induces the oriented growth of Cu-BTC metal organic framework (MOF) crystals through coordinative interactions. These Al2O3@TiO2@Cu-BTC MOF beads show very strong absorptive capability for major components of essential oils, except for a single cyclic ether eucalyptol with steric hindrances. The eucalyptol was fractionated by using the column packed with those modified alumina beads from raw materials of Artemisia argyi, and Rosmarinus officinalis with high purities up to 96% and 93%, respectively.

The sweet wormwood essential oil and its two major constituents are promising for a safe control measure against fall webworm

The fall webworm, Hyphantria cunea (Drury), is a harmful polyphagous global defoliator. The major chemical components of Artemisia annua essential oil (EO) was found to contain (±)-camphor (16.42%), 1,8-cineole (6.22%), α-pinene (6%), caryophyllene (5.19%), and α-selinene (5.17%). The highest toxicity was recorded for EO of A. annua (LD50 = 305.05 μg/larva), followed by (±)-camphor (LD50 = 465.03 μg/larva) and 1,8-cineole (LD50 = 573.49 μg/larva). The binary mixtures of compounds expressed a weaker activity compared to individuals. The (±)-camphor was found to be antagonistic to 1,8-cineole. The biochemical compounds of treated larvae were also determined. The activity level of alanin and aspartate aminotransferase decreased sharply while acid and alkaline phosphatase increased. Activity of lactate dehydrogenase was significantly higher than the control group at 24 h, but decreased significantly after 48 h in all treatments. The activity of esterases were decreased in the treated larvae. The glutathione S-transferase significantly increased in all time intervals. Overall the current results suggest that the sweet wormwood (A. annua) EO and its components could be a safe and environmentally friendly approach in possible control of fall webworm (H. cunea).

Antimicrobial Effects of Combinations between Essential Oils, Antibiotics, and Major Components of Essential Oils

Combinations between antibiotics and other antimicrobial substances such as plant essential oils represent one of the most promising advances against drug-resistant microorganisms. This study aimed to evaluate the antimicrobial effects of different combinations of two essential oils (EO) with its major components and antibiotics (cephalosporines) against Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Candida albicans using the microdilution method. Two plants widely growing in north Algeria, Thymus algeriensis and Salvia officinalis, were investigated. GC/MS was carried out to analyze the chemical composition of essential oils extracted from these plants through the hydrodistillation method. Extraction yields were evaluated at 2.3% for Thymus algeriensis and 3.18% for Salvia officinalis. GC/MS analysis revealed the existence of 29 and 18 essential oil components for Thymus algeriensis and Salvia officinalis, respectively. The major components were thymol (45.067%) and carvacrol (12.24%) for Thymus algeriensis, camphor (18.72%), 1,8-cineol (11.75%) and viridiflorol (10.57%) for Salvia officinalis. Synergistic interaction was observed with cefazoline-Thymus algeriensis essential oil, eucalyptol-Salvia officinalis essential oil and thymol-eucalyptol combinations tested against Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Candida albicans. Additional effect was noted with cefotaxime-alpha pinene and Thymus algeriensis essential oil-eucalyptol combinations tested against Staphylococcus aureus and Candida albicans. However, no significant action was observed among the following combinations: cefotaxime-thymol, eucalyptol-alpha pinene, and thymol-Thymus algeriensis essential oil tested against Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Candida albicans.

Detection of Carvacrol Content in Oregano Essential Oil by Molecularly Imprinted Polymer Coated Quartz Crystal Microbalance Sensor

The essential oil extracted from the oregano (Origanum vulgare) is rich in phenolic compounds that have strong antioxidant and antibacterial properties. Carvacrol is the major component of oregano essential oil. The current study describes the use of a molecularly imprinted quartz crystal microbalance (QCM) sensor to detect carvacrol in oregano essential oil. For the formation of the sensing film, the surface of a quartz crystal with a silver electrode was modified by simple drop coating with a synthesized polymer solution and thermally polymerized at 95°C in an inert atmosphere. The polymer was synthesized by copolymerization of styrene, methyl methacrylate, acrylonitrile and divinylbenzene in an optimum ratio with template carvacrol. The analytical performance of the sensor has been observed to be reasonably good (sensitivity – 1.24Hz/ppm) and has adequate repeatability and reproducibility. Linear calibration curves were obtained in the concentration range of carvacrol between 5–300 ppm. The molecularly imprinted polymer structure and surface morphology were analyzed by FTIR spectroscopy, SEM and AFM. Validation of the proposed sensor with oregano essential oil samples has been performed by correlating the frequency deviation of the sensor with the estimations of carvacrol obtained from gas chromatography.

Insecticidal properties of Clausena austroindica leaf essential oil and its major constituent, trans-anethole, against Sitophilus oryzae and Tribolium castaneum

In this study, the chemical profile of the leaf essential oil of hitherto uninvestigated shrub Clausena austroindica B.C.Stone & K.K.N.Nair and its insecticidal potential against two stored product pests, Sitophilus oryzae (L.) and Tribolium castaneum (Herbst) are being investigated. Essential oils from the leaves of C. austroindica collected from two locations in south India were isolated by hydrodistillation and analyzed by gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Six to eight compounds comprising 99.41–99.44% were characterized with trans-anethole (phenyl propanoid) as the major component (95.12–97.44%) in leaf essential oils. Trans-anethole was isolated from the leaf oil by column chromatography, characterized by Fourier Transform Infrared (FT-IR), ultraviolet-visible (UV-Vis), 1H-, 13C- and distortionless enhancement by polarization transfer (DEPT 135) nuclear magnetic resonance (NMR) spectroscopy, and quantified by external standardization. Insecticidal activity of C. austroindica leaf oil and trans-anethole were assessed against the rice weevil (S. oryzae) and red flour beetle (T. castaneum) by contact and fumigant toxicity assays. Mammalian cell toxicity of C. austroindica leaf oil and trans-anethole was also tested against L929 cell lines using (3-(4,5-dimethylthiazol-2-yl)−2,5-diphenyltetrazolium bromide) MTT assay and quantification of reactive oxygen species (ROS). C. austroindica leaf oil and trans-anethole demonstrated superior contact and fumigant toxicities against adult beetles of S. oryzae and T. castaneum. C. austroindica leaf oil and trans-anethole showed potential fumigant toxicity against S. oryzae (lethal concentration 50 (LC50) 38.80 & 76.98 µL/L) and T. castaneum (LC50 35.65 & 29.10 µL/L). Relatively less prominent viz., S. oryzae: LC50 leaf oil 469.70 µL/L, trans-anethole 2543.20 µL/L; T. castaneum: LC50 leaf oil, 1090.70 µL/L, trans-anethole 2050.84 µL/L, but significant contact toxicities were displayed by the leaf oil and trans-anethole against the two stored product pests. Both C. austroindica leaf oil and trans-anethole (< 2.0 µg/mL) have not demonstrated any mammalian cell (L929 cell line) toxicity. Our study demonstrates the potential of C. austroindica leaf essential oil as a new botanical insecticide for controlling stored product pests. Its major component, trans-anethole, also showed prominent insecticidal activity.

Nanoencapsulation of n-butanol extract of Symphytum kurdicum and Symphytum asperrimum: Focus on phytochemical analysis, anti-oxidant and antibacterial activity.

Objective(s):The current study’s objectives were to obtain different extracts and essential oils of Symphytum kurdicum and Symphytum asperrimum and to determine the chemical composition, as well as to evaluate free radical scavenging activity (IC50) and minimum bactericidal concentration (MBC), and the effect of liposomal formulation on antimicrobial properties.Materials and Methods:Air-dried powdered aerial parts of S. kurdicum and S. asperrimum were used. The antioxidant and antibacterial properties, essential oil compositions, total phenol, and flavonoid contents of different fractions were determined by DPPH test, disk diffusion assay, gas chromatography-mass spectrometry, Folin-ciocalteu reagent, and colorimetric assay method, respectively. The film hydration method was used to fabricate nanoparticles.Results: GC-MS analysis indicated that hexafarnesyl acetone was a major essential oil component. n-butanol and ethyl acetate extracts of S. kurdicum had the highest anti-oxidant activity. Extracts of both plants showed antimicrobial activity. The extracts’ maximum inhibition zones against Staphylococcus epidermidis were established. A particle size analyzer detected the formulation size of 140 nm. The optimum formulation of liposomes contains the ratio of 75 mg lecithin, 25 mg cholesterol, and 50 mg herbal extract. Despite the nanoparticles’ appropriate particle size, the liposomal extract’s antimicrobial effect was lower than that of the free form.Conclusion:Our findings demonstrated that extracts have significant antibacterial and anti-oxidant activities, attributed to their bioactive constituents.

English

Amongst the most important agricultural products in Brazil, the soybean stands out, mainly as an export good. One of the end-of-cycle diseases, Anthracnose, caused by the fungus Colletotrichum truncatum (Schwein.) leads to severe damage to grain quality and yield. The use of natural products as a substitute for conventional pesticides for plant diseases control is an alternative found to reduce food contamination and environmental impacts. However, despite the progress made, much work still needs to be done to enable the safe and effective use of alternative products. Thus, this study aimed to test efficacy of noni essential oil (EO), combined with adjuvants, in the control of anthracnose in soybean plants. Gas chromatography was performed to identify the chemical profile of the EO. In vitro mycelial growth inhibition tests and analyzes on the stimulation of phytoalexin production were also performed. In the field trial, two soybean cultivars submitted to EO were used combined with orange and mineral oils as adjuvants. Octanoic acid (OA) was identified as the major component of EO. There was efficacy in the control of C. truncatum by EO and OA in vitro, as well as the induction of the production of the phytoalexin gliceolin in soybean seedlings with an increase of almost 80% with OA but with no impact on the growth of Trichoderma sp. Between the soybean cultivars tested, Coodetec 2728 IPRO presented lower severity to anthracnose symptoms, however, the cultivar Brasmax Foco demonstrated good tolerance to pathogen&rsquo;s attack maintaining high productivity. Application of fungicides on the cultivar Coodetec 2728 IPRO resulted in a detrimental effect on yield possibly due to induction of the green stem syndrome formation in plants and a harvest delay of 15 days. Key words: Morinda citrifolia L., Glycine max L.; Colletotrichum truncatum, Trichoderma sp, alternative control.

Acaricidal Efficacy of Plants from Ecuador, Ambrosia peruviana (Asteraceae) and Lepechinia mutica (Lamiaceae) against Larvae and Engorged Adult Females of the Common Cattle Tick, Rhipicephalus microplus.

Control measures against common cattle tick Rhipicephalus microplus are of the upmost importance because of considerable, deleterious impact on a farm’s economy. Due to resistance phenomena to synthetic acaricides being a constraint in affected farms, the search for plant derivatives as acaricides has increased dramatically in recent years. In this work, essential oils obtained from two Ecuadorian plants, Ambrosia peruviana and Lepechinia mutica (EOAp, EOLm), traditionally used as insecticides in indigenous communities, were studied on larvae and engorged females at the parasitic stages of R. microplus. Larvae and females were treated with five (0.0625, 0.125, 0.25, 0.50 and 1%) and six concentrations (0.125, 0.25, 0.50, 1, 2 and 4%), respectively, of each EOsAp/Lm. A 98–99% larval mortality was achieved with 0.5% of both EOsAp/Lm. EOAp inhibited oviposition and egg hatching up to 82% and 80%, respectively, and had an overall efficacy of 93.12%. Efficacy of EOLm was 72.84%, due to the low influence of EOLm on reproductive parameters. By steam distillation and GC-MS analysis, γ-Curcumene was identified as the main constituent (52.02%) in the EOAp and Shyobunol (10.80%) in EOLm. The results suggest that major components of both essential oils should be further studied as promissory acaricides against R. microplus.

On the synergy/antagonism of selected terpenes in the effect on lipid membranes studied in model systems

In this work the influence of the mixtures of four terpenes on the lipid monolayers and bilayers imitating bacteria membrane was analyzed. The aim of these investigations was to verify possible synergistic/antagonistic effects occurring between terpenes and affecting their influence on membranes. The studies were performed for major and minor components of the hop essential oil, namely: β-myrcene, α-humulene, E-β-Farnesene and limonene. The experiments on monolayers were based on the studies on penetration of terpenes and their mixtures into model systems, on the surface pressure-area measurements, and Brewster angle microscopy studies, while for bilayers they involved the hydrodynamic diameter, zeta potential and steady-state fluorescence anisotropy measurements of liposomes. Based on the collected results it was concluded that the synergy occurring between selected terpenes increases the effect of their mixtures on monolayers and bilayers as compared to particular components. Among the studied mixed terpene systems the equimolar myrcene/humulene/farnesene/limonene system was found to penetrate the most strongly into the monolayer and change its morphology as well as to make the bilayer more fluid. Additionally, from the comparison of these results with those published for the hop oil it was summarized that neither the studied mixtures nor the individual studied terpenes change the properties of the model membranes as effectively as the total extract. Thus, the action of the hop oil on membrane is not determined by its major components but it is rather the result of the interactions and synergy between major and minor components.

APPLICATION OF NEAR INFRARED SPECTROSCOPY COMBINED WITH MULTIVARIATE ANALYSIS FOR SCREENING FOLIAR MAIN ESSENTIAL OIL COMPONENTS IN BAY LAUREL

Ground bay laurel leaf samples (10–15 g) were scanned using Fourier-transform near-infrared (FT-NIR) spectrometer with reflectance mode in the 1000–2500 nm wavelength range. According to the wet chemical analyses, the essential oil content of the samples from different locations varied between 1.77 and 5.30%. The major component of essential oil was 1-8 cineole with a concentration of 43.4–58.1%. The regression coefficients of calibration (R2CAL) and validation (R2VAL) for essential oil and 1-8 cineol content with partial least square regression (PLSR) actualized as 0.96–0.98 and 0.98–0.98, respectively. The prediction accuracy of the final NIRS model was reasonable, with acceptable root mean standard errors of prediction (RMSEP) of 0.18% and 0.45%. According to the residual predictive deviation (RPD) index (3.58 and 8.41), the accuracy of the NIRS models was regarded as the best. The PLSR model differentiated bay laurel genotypes very well on the first principal component (PC1), based on the related properties.

Effect of environmental factors on the fruit essential oils of Pistacia terebinthus L. growing wild in Turkey

Background: The aim of this study was to investigate the effect of environmental factors on the essential oil yields (EOYs) and major essential oil components in the ripe fruits of Pistacia terebinthus L. (turpentine tree), which is a medicinal and aromatic plant. Fruit samples were collected from 34 different locations of the turpentine tree growing wild in the Lake District in the Mediterranean Region of Turkey. EOYs (%, v/w) and essential oil component ratios (%) were determined in fruit samples by hydrodistillation and GC-MS methods, respectively. The effect of environmental factors on these variables were analyzed using Pearson Correlation and Principal Component Analysis. Results: The essential oil yield of fruits collected from different localities ranged from 0.05% (v/w) to 0.19% (v/w). In terms of average values, α-pinene with 41.01% and limonene with 14.28% were the major components in the essential oils of ripe fruits. Among the environmental variables, longitude and sand % in 10-30 cm were the variables that made a statistically significant difference (p < 0.05) in fruit essential oil yield. According to the results of principal components analysis (PCA), α-pinene and Ocimene components were most affected by silt (%, 10-30 cm) and pH (%, 30-50 cm) ratios. The longitude and total annual precipitation (mm) were the most determining variables in the sabinene and limonene components, respectively. It was seen that the total lime ratios at different depth levels of the soils taken from the localities were the most effective variables for Myrcene and p-Cymene components. Conclusion: The study findings showed that EOYs and intended volatile component ratios in ripe fruits of turpentine trees grown under appropriate environmental conditions can be increased.