Chemical Profile Of Essential Oil Research Articles

How climate change-related abiotic factors affect the production of industrial valuable compounds in Lamiaceae plant species: a review.

The interest in medicinal and aromatic plants (MAPs) has increased significantly in recent years, driven by the growing demand for natural products. MAPs are a valuable source of secondary metabolites, which renders them useful to a number of industries, including cosmetics, pharmaceuticals, and food. The Lamiaceae family includes economically important MAPs that produce valuable secondary metabolites such as essential oils (EOs) and phenolic compounds (PCs). The quantity and quality of these secondary metabolites are affected by abiotic stress factors. In a climate change scenario, the Lamiaceae is one of the most affected families, especially due to its wide distribution in the Mediterranean region. In the present study, the most common climate-related environmental stress factors, namely, drought, salinity, temperature, light, and heavy metals, were reviewed and discussed in order to assess their impact on the chemical profiles of EOs and PCs, as well as on the biological properties (antioxidant, antibacterial, antimelanogenic, pest-repellent, and UV-protective) of Lamiaceae species. It can be posited that these stresses typically act as a catalyst for the secondary metabolism of these plants, resulting in increased production of EO compounds (e.g., 1,8-cineole, linalool, camphor, borneol, and limonene) and PCs (e.g., rosmarinic, caffeic, and salvianolic acids) and subsequent enhancement of their biological activities. In view of the industrial applications of these bioactive compounds, it is of interest to explore the changes in secondary metabolism induced by environmental factors as it is possible to increase the accumulation of valuable secondary metabolites.

Do Climate Conditions Affect the Quality of the Apiaceae Fruits’ Essential Oils?

This study investigated the impact of climate conditions on the quality of essential oils extracted from Apiaceae fruits, specifically coriander (Coriandrum sativum var. microcarpum), aniseed (Pimpinella anisum), and annual caraway (Carum carvi var. annuum) grown at three distinct locations in Serbia over three consecutive years. Field experiments were conducted, and essential oils were extracted using a Clevenger-type apparatus followed by gas chromatographic–mass spectrometric analysis for compound identification. Weather conditions during the vegetation periods were recorded, and statistical analyses, including principal component analysis (PCA) and correlation analysis, were performed to assess the volatile compound compositions. Results indicate significant correlations among various compounds within each fruit type, with distinct patterns observed across different years. PCA further elucidates the influence of both year and sampling location on the chemical profiles of essential oils. Cluster analysis reveals clustering primarily based on the year of cultivation rather than geographical location, emphasizing the dominant role of weather conditions in shaping essential oil compositions. This study highlights the intricate relationship between climate conditions and the quality of essential oils in Apiaceae fruits, providing valuable insights for optimizing cultivation practices and enhancing essential oil production. In general, climate conditions strongly influence the coriander, anise, and annual caraway cultivation, and also essential oil quality.

Chemical profiles of essential oils of two cultivars of Melaleuca cajuputi leaves and flowers

In the present study, the differences between the chemical compositions of the essential oils obtained from the leaves and flowers of two cultivars of M. cajuputi collected from Moc Hoa district, Long An province. By using Gas Chromatography-Mass Spectrometry, a total of 105 components have been identified in the essential oils of four samples of two M. cajuputi cultivars such as “Tràm gió” leaves, “Tràm gió” flowers, “Tràm cừ” leaves and “Tràm cừ” flowers. The Agglomerative Hierarchical Cluster (AHC) and Principal Component Analysis (PCA) were performed to show the similarities/dissimilarities in chemical compositions among the four studied samples. As a result, the components of the essential oils of four studied samples were divided into two clusters. Cluster I included two samples such as “Tràm gió” leaf and “Tràm gió” flower with high presence of 1,8-cineole (35.12 and 17.69%), linalool (3.31 and 5.03%), (R)-α-terpinyl acetate (9.17 and 8.1%). Cluster II comprised “Tràm cừ” leaf and “Tràm cừ” flower with the high concentration of α-pinene (9.87 and 12.19%), γ-terpinene (10.48 and 11.3%), p-mentha-2,4(8)-diene (8.8 and 12.7%).

Evaluation of Yield, Chemical Profile, and Antimicrobial Activity of Teucrium polium L. Essential Oil Used in Iranian Folk Medicine.

Teucrium polium L. is used to treat many diseases like abdominal pains, indigestion, colds, and reproductive system diseases in Iranian folk medicine. This study was designed to investigate the yield, chemical profile of essential oil, and antibacterial and antifungal activity of this species. The flowering aerial parts of T. polium were collected from the Margh region of Kashan, Iran. The essential oil of the plant was extracted and separated using the Clevenger apparatus and analyzed using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity of the essential oil against a variety of standard microbial strains was investigated with the Agar well-diffusion method and determination of the lowest growth inhibitory and lethal concentration (MIC and MBC). The results showed that the yield of T. polium essential oil (TPEO) was 0.5778%. Based on the results of GC-MS, 76 compounds (99.3%) were identified in the TPEO, of which α-pinene (9.67%), β-caryophyllene (8.07%), β-pinene (5.04%), nerolidol (4.94%), and oleic acid (4.57%) were the dominant components. The results of antimicrobial tests showed that the TPEO on Staphylococcus aureus created the largest zone of inhibition (~ 14.29 mm). The dominant inhibitory activity of this essential oil was against Gram-negative bacteria Escherichia coli (~ 9.00 mm), which was almost similar to rifampin (~ 11 mm). It seems that the predominance of terpenoid and acidic compounds of the essential oil is one of the possible factors of the anti-bacterial activity of this essential oil. Therefore, the TPEO may be a promising and potential strategy to inhibit some bacterial strains.

Exploring the versatility of sesquiterpene biosynthesis in guava plants: a comparative genome-wide analysis of two cultivars

Psidium guajava L., a fruit crop belonging to the Myrtaceae family, is highly valued for its nutritional and medicinal properties. The family exhibits a diverse chemical profile of essential oils and serves as a valuable resource due to its ecological interactions, adaptability, and dispersal capacity. The Myrtaceae family has been extensively studied for its terpenoids. Genetic studies have focused on foliar terpene yield in species from the Eucalypteae and Melaleucaceae tribes. To understand the evolutionary trends in guava breeding, this study predicted terpene synthase genes (TPS) from different cultivars. Through this analysis, 43 full-length TPS genes were identified, and approximately 77% of them exhibited relative expression in at least one of the five investigated plant tissues (root, leaf, bud, flower, and fruit) of two guava cultivars. We identified intra-species variation in the terpene profile and single nucleotide polymorphisms (SNPs) in twelve TPS genes, resulting in the clustering of 62 genotypes according to their essential oil chemotypes. The high concentration of sesquiterpenes is supported by the higher number of TPS-a genes and their expression. The expansion for TPS sub-families in P. guajava occurred after the expansion of other rosids species. Providing insight into the origin of structural diversification and expansion in each clade of the TPS gene family within Myrtaceae. This study can provide insights into the diversity of genes for specialized metabolites such as terpenes, and their regulation, which can lead to a diverse chemotype of essential oil in different tissues and genotypes. This suggests a mode of enzymatic evolution that could lead to high sesquiterpene production, act as a chemical defense and contribute to the adaptive capacity of this species to different habitats.

Chemical Profile of Essential Oils of Selected Lamiaceae Plants and In Vitro Activity for Varroosis Control in Honeybees (Apis mellifera).

The most significant ectoparasitic mite of honeybees, Varroa destructor, has a detrimental effect on bee health and honey output. The principal strategy used by the control programs is the application of synthetic acaricides. All of this has resulted in drug resistance, which is now a major worry for beekeeping. As a result, research on alternate products and techniques for mite management is now required. The aim of this study was to determine whether essential oils (EOs) extracted from botanical species of Lamiacae, typical of the Calabria region of Southern Italy, could reduce the population of the mite V. destructor. Among the best-known genera of the Lamiaceae family are oregano, rosemary and thyme, whose EOs were employed in this study. By steam distillation, the EOs were extracted from Origanum vulgare subsp. viridulum (Martrin-Donos) Nyman, Thymus capitatus Hoffmanns. and Link, Thymus longicaulis C.Presl and Salvia rosmarinus Schleid. plant species harvested directly on the Calabrian territory in their balsamic time. Each EO went to the test in vitro (contact toxicity) against V. destructor. Fifty adult female mites, five for each EO and the positive and negative control, were used in each experimental replicate. The positive controls comprised five individuals treated to Amitraz dilute in acetone, and the negative controls included five individuals exposed to acetone alone. To create the working solution to be tested (50 μL/tube), the EOs were diluted (0.5 mg/mL, 1 mg/mL, 2 mg/mL and 4 mg/mL) in HPLC-grade acetone. After 1 h of exposure, mite mortality was manually assessed. Origanum vulgare subsp. viridulum, Thymus capitatus and Thymus longicaulis were the EOs with the highest levels of efficiency at 2 mg/mL, neutralizing (dead + inactivated), 94%, 92% and 94% of parasites, respectively. Salvia rosmarinus EO gave a lower efficacy, resulting in a percentage of 38%. Interestingly, no adverse effects were highlighted in toxicity tests on honeybees. These results show that these OEs of the Lamiaceae family have antiparasitic action on V. destructor. Therefore, they could be used, individually or combined, to exploit the synergistic effect for a more sustainable control of this parasite mite in honeybee farms.

Characterization and Evaluation of the In Vitro Antioxidant, α-Glucosidase Inhibitory Activities of Camellia longii Orel and Luu. (Theaceae) Flower Essential Oil and Extracts From Vietnam

Objective/Background: Camellia longii Orel and Luu was discovered for the first time in Cat Tien National Park of Lam Dong Province, Southern Vietnam, was determined as a new species. To the best of our knowledge, this is the first report on the phytochemical and bioactivity of this species. Methods: The chemical profile of essential oil (EO) prepared from C. longii flowers was determined by GC/MS analysis and comparison of the recorded retention indices and the corresponding literature values. The total phenolic and flavonoid contents in different flower extracts were estimated by Folin-Ciocalteu and aluminum chloride methods with a spectrophotometer, respectively. The antioxidant activities of the extracts were determined by various bioassays, including DPPH free radical scavenging, ferric reducing power, and cupric reducing antioxidant capacity. The α-glucosidase inhibitory activity of the extracts was evaluated using p-nitrophenyl α-D-glucopyranoside solution as a substrate and acarbose as the positive control. Results: Fifty-seven compounds were identified from the EO of C. longii flowers. Among these, the main components were α-eudesmol (16.1%), followed by ( E)-nerolidol (13.0%), β-eudesmol (8.9%), τ-cadinol (6.5%), and γ-eudesmol (5.8%). The total phenolic and flavonoid contents were found high in ethyl acetate, n-butanol, and ethanol extracts (206.8-378.6 mg gallic acid equivalents/g crude extract and 298.5-390.3 mg rutin equivalents/g crude extract, respectively). These extracts were shown to possess potent antioxidant activities in the examined bioassays. As for the α-glucosidase inhibitory assay, the ethyl acetate, butanol, and ethanol extracts were shown to be more potent than acarbose with IC50 values of 2.16 ± 0.04, 1.95 ± 0.05, and 1.53 ± 0.04 μg/mL, respectively. Conclusion: The findings first provide the phytochemical profiles of Camellia longii Orel and Luu and its bioactivities, indicating moderate potentials in antioxidant activity and strong α-glucosidase inhibition.

Untargeted metabolomics approach of essential oils to differentiate five Ocimum species and their anti-choline-sterase and anti-tyrosinase activity

Chemical profiling of essential oils (EOs) from Ocimum species can lead to species identification and the valorization of their potential use in the food and flavour industries. This research was undertaken to discriminate chemometrically between five very closely related species of Ocimum, viz., O. tenuiflorum (green basil), O. tenuiflorum (purple basil), O. gratissimum, O. kilimandscharicum, and O. basilicum, based on their leaf EOs, to identify the differential volatile organic compounds (VOCs), and to determine their anti-cholinesterase and anti-tyrosinase activities. The leaf EO compositions were determined using GC-MS, and a total of 67 metabolites were identified. Untargeted metabolomics and multivariate analysis showed clear discrimination among the studied species based on their VOCs composition. PLS-DA (Partial least squares-discriminant analysis) identified the characteristic VOCs responsible for discrimination among the species. Based on VIP scores, the top 10 metabolites for discrimination among the selected species were detected, viz., linalool, α-cadinol, γ-murrolene, β-ocimene, α-eudesmol, γ-eudesmol, α-selinene, E-β-farnesene, humulene epoxide II and linalyl acetate. The quantification (mg/μL) of eugenol, β-caryophyllene, linalool, β-ocimene, and neo-allo-ocimene of the isolated leaf EOs were done by comparing with the standards. O. basilicum showed the highest AChE inhibitory activity whereas, O. tenuiflorum (green basil) showed the highest tyrosinase inhibition. These results led to the conclusion that the EOs of edible Ocimum species exhibit important enzyme inhibitory activities and can be potential sources of natural active ingredients for memory-enhancing as well as progressive neurodegenerative disorders and also as non-toxic skin lightening and anti-browning agents for fruits, vegetables, and other food substances.

Chemical compositions and different biological activity of leaf essential oil of Ocimum americanum L. grown in acidic soil conditions

s Ocimum americanum L. is a highly valued aromatic plant whose leaves are used not only in traditional cuisine but also in the food, cosmetic, and pharmaceutical industries. This study aimed to identify the chemical profile of essential oil extracted from the leaves of Ocimum americanum by GC-FID and GC/MS grown in acidic soil conditions in the NE region of India. Furthermore, the biological activities like antioxidant, anti-diabetic, anti-inflammatory, and anti-tyrosinase activity were analyzed, as per standard methods. GC and GC/MS analysis identified 16 compounds in which citral-a (48.25%) was found as a major compound, followed by carveol (41.64%). The antioxidant activity was performed using DPPH and ABTS methods; and IC50 value obtained was 8.85 μL/mL and 28.82 μL/mL, respectively. The leaf essential oil of O. americanum exhibited strong anti-diabetic and anti-inflammatory activities, whereas moderate anti-tyrosinase activities with IC50 values of 40.84, 12.81, and 182.74 μL/mL, respectively. Furthermore, the ant-microbial activity was evaluated for four bacterial and four fungal strains, revealing that O. americanum essential oil expresses antifungal activity against S. cereviaceae only with a MIC value of 5±0.47 μg/mL. These evidences clearly indicates that essential oil obtained from the leaf of O. americanum showed potential anti-inflammatory and anti-diabetic activity that can be used as an alternative in pharmaceuticals and food industries as a natural source.

A comparative study on essential oils from the leaves and stems of Vietnamese Mikania micrantha Kunth

Mikania micrantha Kunth is widely known as potential herbal medicine, although it is an invasive alien species in Southeast Asia. In this study, the essential oils from leaves and stems of M. micrantha were extracted by hydrodistillation method, and the chemical profiles of essential oils were then analysed by gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC/MS). It was found that there were similarities and differences in chemical compositions and their percentage between the essential oils obtained from these two parts. The dominant components of leaves essential oil are β-Cubebene, Germacrene D, and α-Zingiberene, accounting for 11.34%, 10.96%, and 10.76%, respectively. Additionally, the major components of stems essential oils are D-Limonene (16.99%), β-Pinene (7.91%), and α-Zingiberene (7.26%). The research sheds fresh light on the chemical makeup of M. micrantha essential oils, emphasising their potential for the future.

Hop Tropicalization: Chemical Compositions of Varieties Grown under Organic and Conventional Systems in Subtropical Conditions

The interest in the production of hops in Brazil, motivated by the third position in the world ranking of beer producers and the growth of the craft brewery business, justifies the intensification of studies into its adaptation to local growing conditions. Due to the high internal demand, the aim of this study was to evaluate the phytochemical profiles of hop varieties grown in subtropical conditions under different cropping systems. Studies that promote the expansion of cultivation areas in distinct climate conditions and ensure quality are very important. A randomized block design was adopted with a 2 × 5 subdivided plot. The main factor was the cropping system (organic and conventional), and the secondary factor was the hop variety (Columbus, Chinook, Nugget, Cascade and Hallertau Mittelfrüeh), with four blocks and four plants per plot. The quality parameters monitored in this work were the contents of alpha and beta acids, and xanthohumol in the inflorescences of hops, as well as the relative composition of their essential oils. The variations in the chemical profiles of essential oils showed differences between some varieties, and the different compositions and levels resulting from the two cropping systems show that management and cultural practices can influence the aromatic characteristics of hops; in total, 23 compounds were found. The terpene fraction represented 79.67% of the oil in Hallertau and 93.63% in Cascade, with myrcene being the main compound. The levels of bitter acids and xanthohumol did not differ statistically as a function of the treatments. This study contributes the first records of the chemical profiles of hops grown in subtropical conditions in Brazil, in general, the Nugget variety had the highest qualitative potential

Gamma-irradiation effect on the chemical composition and antibacterial activity of the moroccan tanacetum annuum L. essential oil

The primary objective of the present inquiry was to assess the impact of gamma irradiation on the chemical composition and antibacterial potential of the essential oil extracted from the aerial parts of Moroccan Tanacetum annuum L. to this end, two distinct irradiation doses of 5 kGy and 10 kGy were administered to the essential oil, and the resultant effects were evaluated via analysis of the oil's chemical composition and antibacterial activity. The study findings have revealed that irradiation technology possesses the remarkable ability to modulate the concentrations of specific chemical constituents in a manner that effectively amplifies the antibacterial activity of the essential oil. Moreover, the technology has evinced the generation of novel compounds while also demonstrating the eradication of certain pre-existing ones upon the oil's exposure to irradiation. These discoveries have emphasized the potential of irradiation technology for augmenting the chemical profile of essential oils, thereby mitigating the risk of contamination via microbiological, physical, or chemical means, ultimately enhancing the therapeutic efficacy of the plant and its essential oil. Furthermore, the results of this study signify the possibility of harnessing irradiation technology in the production of various natural products and essential oils. The present research has thus broadened the horizons for the application of irradiation technology in advancing the potency and safety of essential oils, paving the way for a diverse range of applications in different fields, such as medicine.

Essential Oils of Rosmarinus officinalis and Eucalyptus globulus Cultivated in the Mountainous Region of the State of Rio de Janeiro (Brazil): Chemical Profile and Antileishmanial Activity

Pharmacognosy Research,2023,15,2,297-306.DOI:10.5530/pres.15.2.032Published:February 2023Type:Original Article Authors:Rogéria Cristina Zauli, Tarcísio Martins Santos, Alberto Wisniewski Jr, Patrícia Xander, and Aislan Cristina Rheder Fagundes Pascoal Author(s) affiliations:Rogéria Cristina Zauli1, 2, 3, Tarcísio Martins Santos4, Alberto Wisniewski Jr4, Patrícia Xander1, 3, Aislan Cristina Rheder Fagundes Pascoal5,* 1Department of Pharmaceutical Sciences, Institute of Environmental, Chemical and Pharmaceutical Sciences, Laboratory of Cellular Immunology and Biochemistry of Fungi and Protozoa, Federal University of São Paulo, Diadema, São Paulo, BRAZIL. 2Technical Support Center for Teaching, Research and Extension (NATEPE), Federal University of São Paulo, Campus Diadema, Diadema, São Paulo, BRAZIL. 3Biology-Chemistry Graduate Program, Federal University of São Paulo, Campus Diadema, Diadema, São Paulo, BRAZIL. 4Department of Chemistry, Federal University of Sergipe, Av. Marechal Rondon, São Cristóvão, SE, BRAZIL 5Department of Basic Sciences, Multi-user Biomedical Research Laboratory, Fluminense Federal University (ISNF-UFF), Nova Friburgo, Rio de Janeiro, BRAZIL. Abstract:The present study aimed to characterize the chemical profile of essential oils of Rosmarinus officinalis (EORo) and Eucalyptus globulus (EOEg) cultivated in the mountainous region of the state of Rio de Janeiro, Brazil, and to verify the leishmanicidal potential, as well as to determine the cytotoxicity in vitro in mammalian cells. EORo had α-Pinene (37.99%), Cineol (21.48%), D-Verbenone (5.78%) and Limonene (3.28%) as major constituents. The EOEg had as major components Cineol (75.52%), Limonene (8.82%) and o-Cymeno (7.81%). The EOEg had a lower IC50 value of 14.03 ± 2.08 μg/mL, while EORo had an IC50 value of 31.12 ± 4.6 μg/mL, both during the 24-hr exposure period. In the 48-hr period, the IC50 value was almost twice as high with rosemary oil, while in eucalyptus oil there was no significant difference when exposed in this period. The selectivity of EOs was demonstrated in murine cells, showing almost 30 times less toxic to the cell than to the parasite. It can be concluded that this is a pioneering study on the potential of these essential oils against the leishmania parasite. Furthermore, the low toxicity effect on the host cell encourages future studies and in vivo applications. Keywords:cytotoxicity, E. globulus, Essential oil, Leishmanicidal, R. officinalisView:PDF (359.76 KB)

Research Article Chemical profile of essential oil in four <i>Cymbopogon</i> species grown in southern Brazil

Research Article Chemical profile of essential oil in four <i>Cymbopogon</i> species grown in southern Brazil

Chemometric analysis based on GC-MS chemical profiles of essential oil and extracts of black cumin (Nigella sativa L.) and their antioxidant potentials

Chemometric analysis based on GC-MS chemical profiles of essential oil and extracts of black cumin (Nigella sativa L.) and their antioxidant potentials

Chemical Profile of Essential Oil, Extracts and Fractions of Eugenia pyriformis Cambess. and its Antioxidant, Cytotoxic and Allelopathic Activities

HIGHLIGHTS Eugenia pyriformis essential oil (EO) of the leaf contains linalol, terpinen-4-ol; 2-carene; The extract showed β-amiryn (1) and the porphyrin derivatives; The extracts of the leaf and stem showed antioxidant activity; The hexane extract of the stem showed allelopathic activity.

Chemical Composition and Histochemical Localization of Essential Oil from Wild and Cultivated Rhaponticum carthamoides Roots and Rhizomes.

Rhaponticum carthamoides (Willd.) Iljin is not only a source of phytosteroids and flavonoids, but is also source of essential oil (EO). This study evaluated the volatile metabolic constituents and histochemical localization of root and rhizome essential oils (EOs) from R. carthamoides populations wild-grown in Russia and cultivated in Bulgaria. The performed histochemical analysis confirmed the presence of lipophilic substances in the secretory ducts of the examined roots and rhizomes. Both EOs were obtained by hydrodistillation and further analyzed by gas chromatography with mass detection. The results showed differences between the chemical compositions of both EOs. Forty-six components were tentatively identified in R. carthamoides oil from the wild population, with β-selinene (4.77%), estragole (6.32%), D-carvone (6.37%), cyperene (8.78%), and ledene oxide (11.52%) being the major constituents. In the EO isolated from cultivated R. carthamoides, twenty-three compounds were tentatively identified, with humulene (7.68%), β-elemene (10.76%), humulene-1,2-epoxide (11.55%), ledene oxide (13.50%), and δ-elemene (19.08%) predominating. This is the first report describing the histolocalization and chemical profile of EO from R. carthamoides cultivated in Bulgaria. Further research on the cultivation of R. carthamoides in Bulgaria would affect the relationship between its chemical composition and pharmacological effects.

Insecticidal and antifungal effects of lemon, orange, and grapefruit peel essential oils from Argentina

The aim of the present work was to study the bioactivity of lemon, orange, and grapefruit peel essential oils (EOs) obtained from Argentinian plantations on different agronomically important insect and fungal species. The chemical profile of EOs was determined by Gas Chromatography-Mass Spectrometry (GC/MS); the insecticidal activity was studied through contact and fumigant assays; the antifungal activity was evaluated with fumigant tests. Orange EO was the most effective against Rhyzopertha dominica, Oryzaephilus spp. and Sitophilus granarius in fumigation tests (LC50= 89.39, 94.50, and 163.64 µL/L air, respectively); while the insecticidal effect of EOs was species-dependent in contact toxicity assays. Regarding antifungal activity, Rhizoctonia solanii was more susceptible than Sclerotium rolfsii to the tested EOs, with lemon from Industry 1 and orange being the most toxic EOs (MIC=10.77 µL/plate and 11.02 µL/plate, respectively). Conversely, S. rolfsii was strongly inhibited by lemon EO from Industry 2 (MIC= 52.40 µL/plate). Besides limonene, other compounds that could be responsible for these bioactivities were: linalool, carvone, α-pinene, β-pinene, β-myrcene, α-terpineol, terpinen-4-ol, limonene oxide, β-phellandrene, γ-terpinene, sabinene, neral, neryl acetate, β-caryophyllene and p-cymene. Citrus peel EOs can be used against different pests, contributing to the valorization of citrus residues.

Campylobacter jejuni Biofilm Control with Lavandin Essential Oils and By-Products.

The food industry is constantly struggling with one of the most prevalent biofilm-forming and food-borne pathogenic bacteria, Campylobacter jejuni. Different approaches are used to control biofilms in the food production chain, but none is fully effective. In this study, we aim to produce and determine the chemical profile of essential oils (EOs), ethanolic extracts of flowers prior to distillation (EFs), and ethanolic extracts of post-distillation waste material (EWMs) from Lavandula × intermedia ‘Bila’, ‘Budrovka’ St Nicholas and ‘Budrovka’, which were further used to reduce C. jejuni intercellular signaling, adhesion, and biofilm formation, as well as to test their antioxidant activity. Glycosides of hydroxycinnamic acids were the major constituents of both types of lavandin ethanolic extract, while linalool, linalyl acetate, 1,8-cineol, and camphor were the major compounds found in lavandin EOs. Tested EOs showed the best antibacterial activity with a minimal inhibitory concentration of 0.25 mg/mL. Lavandin EFs proved more effective in reducing C. jejuni intercellular signaling and adhesion compared to lavandin EOs and EWMs, while lavandin EOs showed a slightly better effect against biofilm formation. Interestingly, the best antioxidant activity was determined for lavandin EWMs. A positive and moderate correlation was found between the reduction of C. jejuni intercellular signaling and adhesion, as well as between adhesion and biofilm formation. These findings mean novel bacterial targets are of interest for biofilm control with alternative natural agents throughout the whole food production chain.

Encapsulation of Eucalyptus largiflorens Essential Oil by Mesoporous Silicates for Effective Control of the Cowpea Weevil, Callosobruchus maculatus (Fabricius) (Coleoptera: Chrysomelidae)

Although the use of synthetic chemicals is the principal method for insect pest management, their widespread application has led to numerous side effects, including environmental pollution and threats to human and animal health. Plant essential oils have been introduced as promising natural substitutes for synthetic insecticides. However, high volatility and/or low durability are the main limiting factors for essential oil application for control of insect pests. Accordingly, along with an evaluation of the fumigant toxicity of Eucalyptus largiflorens essential oil against the cowpea weevil, Callosobruchus maculatus, essential oil was nanoencapsulated by two mesoporous silicates, MCM-41 and zeolite 3A, to enhance fumigant persistence and toxicity. The chemical profile of essential oil was also analyzed through gas chromatographic-mass spectrometry. E. largiflorens essential oil showed significant concentration-dependent toxicity against insect pests; a concentration of 5.16 μL/L resulted in 100% mortality after 48 h. The toxicity of essential oil could be attributed to the presence of various insecticidal terpenes, such as spathulenol (15.6%), cryptone (7.0%), and 1,8-cineole (5.8%). Fumigant persistence was increased from 6 days to 19 and 17 days for pure and capsulated essential oil with MCM-41 and Zeolite 3A, respectively. The insect mortality also increased from 99 insects in pure essential oil to 178 and 180 insects in MCM-41 and Zeolite 3A encapsulated formulations, respectively. Therefore, the encapsulation of E. largiflorens essential oil by MCM- 41 and Zeolite 3A is a beneficial method for enhancing its persistence and toxicity against C. maculatus.