Chemical composition and in vitro evaluation of antioxidant effect of free volatile compounds from Satureja montana L

As a part of an investigation of natural antioxidants from Dalmatian aromatic plants, in this paper we report a study of the antioxidant activity related to the chemical composition of savory free volatile compounds. Twenty-one compounds were identified in the essential oil without fractionation, representing 97.4% of the total oil. The major compound was phenolic monoterpene thymol (45.2%). Other important compounds were monoterpenic hydrocarbons p-cymene (6.4%) a nd gamma-terpinene (5.9%)and oxygen-containing compounds carvacrol methyl ether (5.8%), thymol methyl ether (5.1%), carvacrol (5.3%), geraniol (5.0%) and borneol (3.9%). The evaluation of antioxidant power was performed in vitro by the beta-carotene bleaching and thiobarbituric acid (TBA) methods. As determined with both methods, the total savory essential oil as well as different fractions or pure constituents containing hydroxyl group exhibited relatively strong antioxidant effect. The hydrocarbons, when isolated as CH fraction, showed the poorest effectiveness in spite the fact that this fraction contained gamma-terpinene, alpha-terpinene, p-cymene and terpinolene which previously were identified as potential antioxidants.     

Comparative analysis of essential oil compositions in seven populations of Bakhtiarian savory in natural and field conditions

Bakhtiarian savory (Satureja bachtiarica Bunge) is an endemic herb growing wild in Iran with interesting pharmacological and biological properties. In this research, the variability of essential oil content and phytochemical compositions among seven populations of this species was studied in both natural and field conditions. There was a wide interpopulation variability in phytochemical variation of studied populations under both natural and field conditions, indicating the existence of different chemotypes. Six chemical compositions showed high value in studied plants so that carvacrol and thymol were known as major compounds and confirmed by principal component analysis. Ilam population had the highest thymol in both field (77.10 %) and natural (42.32 %) conditions and was known as a thymol chemotype. Beside, Yazd and Shahrekord populations, respectively, showed the highest carvacrol percentages in both field (84.83 and 63.81 %) and natural (72.50 and 58.05 %) conditions and were known as carvacrol chemotypes. In other populations, carvacrol and thymol were the main components and showed partly equal percentage and these populations were known as carvacrol/thymol chemotypes. According to Pearson correlation analysis, carvacrol was negatively correlated with p-cymene, γ-terpinene and thymol (r = ?0.61, ?0.70 and ?0.98, respectively), indicating very high reverse correlation between carvacrol and thymol. In conclusion, the high value of the essential oil compositions in studied S. bachtiarica populations could provide useful information for conservation and selection of cross parents in breeding programs to develop improved cultivars.     

Essential oil variability in Thymbra capitata (L.) Cav. growing wild in Southern Apulia (Italy)

Essential oils of Thymbra capitata (Thymus capitatus) collected from Southern Apulia (Italy) were analysed using gas chromatography and gas chromatography–mass spectrometry techniques, to check for chemical variability. The study showed that among the 75 components of the oils the most recurrent ones were thymol and carvacrol, which always constituted more than 50% of the oils, as well as γ-terpinene, borneol and p-cymene. Cluster analysis led to the identification of three chemotypes: thymol, carvacrol and thymol/carvacrol; this was presumably a crossbreed between the other two chemotypes. Principal component analysis showed the direct correlation among myrcene, α-terpinene and γ-terpinene; anti-correlation between thymol and carvacrol, and the inverse correlation between linalool and myrcene. Moreover, lower thymol concentrations were accompanied by an increase in myrcene, α-terpinene and γ-terpinene.     

Influence of environmental and genetic factors on the stability of essential oil composition of Thymus pulegioides

Thymus pulegioides plants were collected from various natural habitats of Lithuania and transferred into a new uniform environment. The plants were cloned annually at controlled conditions and their essential oil composition was monitored by capillary GC and GC/MS. The geraniol/geranial/neral (G/G/N), thymol (T), linalool (L), carvacrol/γ-terpinene/p-cymene (C/γT/pC) and thymol/carvacrol/γ-terpinene/p-cymene (T/C/γT/pC) chemotypes of T. pulegioides were studied. It was found that according to the stability of essential oil composition on a sudden change of environmental conditions two types of T. pulegioides can be distinguished: (1) plants which preserve their chemical composition of the essential oils; (2) plants, which considerably change their chemical composition of the essential oils.     

Inhibition of oxidation of unsaturated fatty acid methyl esters by essential oils

The essential oils from 16 various spice plants were studied as natural antioxidants for the inhibition of autooxidation of polyunsaturated fatty acids methyl esters isolated from linseed oil. The content of methyl oleate, methyl linoleate, and methyl linolenoate after 1, 2, and 4 months of autooxidation were used as criteria to estimate the antioxidant efficiencies of essential oils. In 4 months, 92% of the methyl linolenoate and 79% of the methyl linoleate were oxidized in a control sample of a model system. It was found that the most effective antioxidants were essential oils from clove bud, cinnamon leaves, and oregano. They inhibited autooxidation of methyl linolenoate by 76–85%. The antioxidant properties of these essential oils were due to phenols— eugenol, carvacrol, and thymol. Essential oil from coriander did not contain phenols, but it inhibited methyl linolenoate oxidation by 38%. Essential oils from thyme, savory, mace, lemon, and tea tree inhibited methyl linolenoate oxidation by 17–24%. The other essential oils had no antioxidant properties.     

Studies on Leaf Oils of Citrus Species

Leaf oils from 6 domestic citrus species were analysed by gas chromatography and 32 compounds were identified as constituents of one or more oils. Most components present were common to all 6 citrus leaf oils, but the percent composition of some components, i.e. β-pinene, limonene, β-phellandrene, γ-terpinene, p-cymene, p-α-dimethylstyrene, citronellal, linalool and thymol methyl ether, differed considerably from species to species. For example, γ-terpinene is a main component (36.5%) of Shiikuwasha (Citrus depressa Hayata), but is a trace in leaf oils from Kawabata-mikan (C. aurea Tanaka) and Otaheite-orange (C. limonia Osbeck var. otaitensis Tanaka). Yuzu (C. Junos Sieb. ex Tanaka) is characterized by relatively high contents of β-phellandrene (11.2%) and p-α-dimethylstyrene (6.7%), which are minor constituents in the other 5 citrus leaf oils. Otaheite-orange is characterized by high contents of limonene (39.7%) and citronellal (10.0%).     

Chemical composition and antioxidant and anticandidal activities of essential oils from different wild Moroccan Thymus species

Samples of the aerial parts of Thymus broussonetii, T. ciliatus, T. leptobotrys, T. maroccanus, T. pallidus, T. satureioides, and T. serpyllum collected from different natural regions in southern and south-western Morocco were analyzed for their qualitative and quantitative essential oil profiles. In total, 46 compounds, representing more than 99% of the oils, were characterized. Monoterpenes, both hydrocarbons (12.9-58.0%) and oxygenated monoterpenes (38.8-81.1%), were the principal classes of compounds for most of the thyme species studied. Cluster analysis allowed the classification of the species into three main groups: a carvacrol group (Group I), comprising the species T. maroccanus and T. leptobotrys, a linalyl acetate and (E)-nerolidol group (Group II), represented by T. serpyllum, and a thymol and/or carvacrol, γ-terpinene, and p-cymene group (Group III), composed of T. satureioides, T. broussonetii, T. ciliatus, and T. pallidus. The essential oils were screened for their antioxidant and anticandidal activities. The data showed that the oils obtained from T. leptobotrys and T. maroccanus (carvacrol group) possessed the highest antioxidant activities as assessed by the determination of the DPPH free radical-scavenging ability and the ferric-reducing potential. The anticandidal assays indicated that the highest activity was noticed for the essential oil isolated from T. leptobotrys.     

Studies on Leaf Oils of Citrus Species

Leaf oil samples of four Japanese citrus species were analysed by gas chromatography to determine the detailed composition of each leaf oil. The following components were identified: α-pinene, α-thujene, camphene, β-pinene, sabinene, β-myrcene, α-terpinene, limonene, β-phellandrene, trans-2-hexen-1-al, γ-terpinene, p-cymene, terpinolene, cis-2-penten-1-ol, n-hexyl alcohol, cis-3-hexen-1-ol, trans-2-hexen-1-ol, p-α-dimethylstyrene linalool, linalyl acetate, β-elemene, terpinen-4-ol, caryophyllene, humulene, α-terpineol, neryl acetate, geranyl acetate, β-selinene, geraniol and thymol. Most components were contained in common in leaf oils of the four citrus species, but relative contents of some of the components; such as γ-terpinene, linalyl acetate, and thymol differed from species to species. For example, γ-terpinene was the major component (33.8%) of Hassaku, whereas it was only a minor component in Daidai. Daidai is characterized by a very high content of linalyl acetate (35%) which is only a trace in the other three species. Kishu-mikan is characterized by a high content of thymol (15%).     

Variation of Essential Oil Content and Composition,Phenolics, and Yield Related Traits Using Different Pollination Systems in Populations of Thymus Species

The production of self-pollinated plants could be important for improving medicinal plants secondary metabolites. In this study, 11 Thymus populations from eight species were evaluated to determine the effect of self and open pollination on agro-morphological characteristics, total phenolic content (TPC), essential oil (EO) content, and EO components. Inbreeding led to some positive effects of above mentioned traits in most of the studied populations. Total phenolic content ranged from 7.07 to 52.69 mg tannic acid equivalents (TAE) g⁻¹ dry weight (DW) in open pollinated derived populations, while it varied from 1.2 to 55.03 mg TAE g⁻¹ DW in self-pollinated ones. Under open and self-pollination condition, the highest EO content was obtained in T. trautvetteri (3.37 %) and T. pubescens (1.96 %), respectively. Gas chromatography-mass spectrometry (GC/MS) identified 42 compounds including thymol, carvacrol, linalool, p-cymene, γ-terpinene, terpinen-4-ol, and α-terpineol as the main compounds. In most cases, selfed plants compared to open pollinated ones, revealed higher thymol content. T. daenensis-1 showed a significant increase in thymol content (from 25.22 % to 74.3 %) due to self-pollination. Moreover, self-pollination led to emergence of some new compounds. Carvacrol methyl ether was the constituents of Thymus EO that are being reported in self-pollinated populations. Finally, inbreeding in Thymus might be suggested as a useful tool to increase genetic homogeneity for the selection of superior plants for improving secondary metabolite.     

Screening the essential oil composition of wild Sicilian oregano

The qualitative and quantitative composition of the essential oils obtained from wild Sicilian oregano plants has been investigated. Samples were collected from three areas of Sicily namely Val Mazara (M), Val di Noto (N) and Val Demona (D). These areas are based on historical territorial subdivision. The essential oils were obtained by hydrodistillation and analyzed by GC-FID-MS. Seventy eight compounds were identified representing more than 98% of the compounds in the oils. All samples are thymol-chemotype with variable percentage of γ-terpinene, p-cymene, trans-sabinene hydrate, terpinen-4-ol and carvacrol. Statistical analyses were performed in order to evaluate the variability of the essential oils. Six groups were formed reflecting the compositional differences of the essential oil profiles of the wild Sicilian oregano samples.     

<Superscript>1</Superscript>H NMR-based metabolic profiling and target analysis: a combined approach for the quality control of <Emphasis Type="Italic">Thymus vulgaris</Emphasis>

The characterization of T. vulgaris plant material for quality control purposes was performed by NMR-based methods. Direct extraction of 141 T. vulgaris samples with DMSO-d ₆ enabled the obtainment of crude extracts with a representative composition in terms of both volatile and non-volatile constituents. The acquisition of 600 MHz ¹H NMR spectra resulted in a dataset which was analyzed by a combination of metabolic profiling and target analysis approaches. Preliminary analysis of the ¹H NMR spectra was performed by principal component analysis, which revealed sample discrimination on a chemotype basis (thymol, carvacrol and linalool chemotypes). Further minor discriminative constituents were identified as p-cymene, γ-terpinene, rosmarinic acid, and 3,4,3′,4′-tetrahydroxy-5,5′-diisopropyl-2,2′-dimethylbiphenyl. Metabolite identification was accomplished by 1D and 2D NMR techniques and supported by spiking experiments. Fast dereplication of constituents not available as reference compounds was performed by HPLC–SPE–NMR experiments. A targeted approach based on qHNMR was validated for quantification of the identified secondary metabolites. Validation was performed in terms of precision (intra-day RSD ≤ 4.51%, inter-day RSD ≤ 4.18%), repeatability (RSD ≤ 2.30%), accuracy (recovery rates within 93.4 and 103.4%), linearity (correlation coefficients ≥ 0.9990), robustness, and stability. The amount of the dominant monoterpene in thymol, carvacrol, and linalool chemotypes was respectively found to be within 0.4–2.6, 0.7–2.3, and 1.1–3.6% (w/w). Variable amounts of the precursors p-cymene and γ-terpinene were found in thymol and carvacrol chemotypes. The highest amount of rosmarinic acid and 3,4,3′,4′-tetrahydroxy-5,5′-diisopropyl-2,2′-dimethylbiphenyl in the analyzed samples was respectively 4.6 and 0.4% (w/w). Since quantification is performed on a weight basis, the essential oil content can be estimated based on the sum of the quantified monoterpenes. The NMR-based analysis of T. vulgaris represents a more comprehensive approach in comparison to traditional chromatographic methods such as GC and LC, respectively employed for the analysis of volatile and non-volatile constituents. Further advantages lie in the simple sample preparation, rapidity and reproducibility of the NMR analysis.     

Explant type and natural ventilation systems influence growth and content of carvacrol and thymol of Lippia gracilis Schauer

The objective of this study was to evaluate the effects of different natural ventilation systems and explant types on the growth and volatile compound content of Lippia gracilis cultured in vitro. The treatments consisted of four membrane systems (without membrane, with one, two, and four porous membranes) and two explant types (nodal segments with and without a pair of leaves). The evaluation of growth, photosynthetic pigments and chemical analysis of the volatile fraction were performed at 35 days of cultivation in half strength MS basal medium. Natural ventilation systems significantly influenced the in vitro growth and volatile fraction of L. gracilis. Explants with a pair of leaves obtained the best experimental responses. The natural ventilation system with four membranes provided the best growth parameters and leaf area response of L. gracilis explants with leaves. The photosynthetic pigments decreased with an increase in the number of porous membranes in the culture flask. Variations in the number, content, and profile of volatile compounds under the influence of natural ventilation systems were observed. Major constituents such as ρ-cymene, γ-terpinene, thymol, carvacrol, and E-caryophyllene, regardless of experimental conditions, were identified. The highest carvacrol and thymol contents were observed in plantlets grown in culture flasks with four porous membranes. To maximize the content of carvacrol and thymol from the in vitro culture of L. gracilis, explants with a pair of leaves and four porous membranes in culture flasks are recommended for use.

     

Morpho-physiological and phytochemical traits of (<Emphasis Type="Italic">Thymus daenensis</Emphasis> Celak.) in response to deficit irrigation and chitosan application

Thymus daenensis Celak. is an aromatic herb used as a popular medicine and its natural products in the form of extracts and essential oil have significant economic values in Iran. We hypothesized that spraying plants grown under deficit irrigation system with chitosan can be considered as an applicable method to enhance essential oil and antioxidant activity in thyme. Response of thyme to three irrigation regimes including well-watered, moderate stress, and severe stress along with three levels of chitosan application rates 0, 200, and 400 μL L^?1 was evaluated in a 2-year study in 2014 and 2015. Drought stress condition significantly shortened phenologic stages, more specifically in the first (establishment) year. All growth parameters were reduced dramatically as drought stress intensified. Imposing even moderate stress reduced leaf area as much as 59 and 44% in the first year and the second year, respectively. Biomass yield of plants grown under severe drought stress decreased substantially, whereas essential oil content and the share of thymol in thyme oil which possesses the greatest degree of biological activity improved. Maximum oil yield (1.50 g plant^?1) was obtained from plants under mild drought stress when sprayed with 400 μL L^?1 chitosan in the second year when plants were well-established. Foliar applications of chitosan reduced the adverse effect of water deficit on oil yield and improved thymol content of the essential oil. Chitosan also increased secondary metabolites including α-terpinene, p-cymene, γ-terpinene, thymol, carvacrol and β-caryophyllene. Leaf flavonoid reduced under deficit irrigation while more phenol was found in plants grown under deficit irrigation. The essential oil of thyme exhibited antioxidant property when the plants were sprayed with 400 μL L^?1 chitosan. The results of this study indicated that thyme can be grown successfully under moderate stress and that application of chitosan elicitor can to some degree compensate the negative impact of deficit irrigation on its biomass and essential oil yield.     

Factors that interact with the antibacterial action of thyme essential oil and its active constituents

The viable counts of Salmonella typhimurium on nutrient agar (NA) decreased upon the addition of either the essential oil of thyme or its constituent thymol, especially under anaerobic conditions. Antagonistic effects of thymol against Staphylococcus aureus were also greater under anaerobic conditions. In contrast to the phenolic constituents of the oil, thymol and carvacrol, the chemically related terpenes p -cymene and y -terpinene had no antagonistic effects against Salm. typhimurium.
The addition of Desferal to NA counteracted the antibacterial effects of both thyme oil and thymol. No support was obtained, however, for a possible role of iron in the oxygen-related antibacterial action of the thyme oil and thymol or for the observed effect of Desferal. In the presence of thymol, the viable counts of Salm. typhimurium obtained on a minimal medium (MM) were lower than those obtained on NA. Addition of bovine serum albumin (BSA) neutralized the antibacterial action of thymol. It is suggested that the effects of BSA or Desferal are due to their ability to bind phenolic compounds through their amino and hydroxylamine groups, respectively, thus preventing complexation reactions between the oil phenolic constituents and bacterial membrane proteins. This hypothesis is supported by the marked decrease in the viable counts of Salm. typhimurium caused by either thyme oil or thymol when the pH of the medium was changed from 6.5 to 5.5 or the concentration of Tween 80 in the medium was reduced.     

GC-MS analysis and in vitro antioxidant and enzyme inhibitory activities of essential oil from aerial parts of endemic Thymus spathulifolius Hausskn. et Velen

We investigated the antioxidant and enzyme inhibitory activities and chemical composition of the hydro-distilled essential oil (0.35% yield) from aerial parts of Thymus spathulifolius. Antioxidant capacity of the oil was assessed by different methods including free radical scavenging (DPPH and ABTS), reducing power (FRAP and CUPRAC) and phosphomolybdenum assay. Inhibitory activities were analyzed against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-amylase, α-glucosidase, and tyrosinase. Twenty-one constituents were identified representing 97.2% of the total oil with thymol (50.5%), borneol (16.7%) and carvacrol (7.7%) as the major components. The essential oil exhibited good antioxidant activity with IC₅₀ values of 3.82 and 0.22?mg/mL determined by free radical scavenging DPPH and ABTS, respectively. EC₅₀ values of FRAP and CUPRAC were found to be 0.12 and 0.34?mg/mL, respectively. The results of the present study support the uses of T. spathulifolius essential oil as a source of natural antioxidants and bioactivities for functional foods and phytomedicines.     

Toxicity and repellency of origanum essential oil and its components against Tribolium castaneum (Coleoptera: Tenebrionidae) adults

The components of Origanum vulgare L. essential oil showing insecticidal activity and repellency against red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae), adults were analysed by GC-MS. All constituents were identified, and the main components were carvacrol (67.2%), p-cymene (16.2%), γ-terpinene (5.5%), thymol (4.9%), and linalool (2.1%). In a vapor phase fumigant assay, the origanum oil was more effective in closed conditions (LD₅₀ = 0.055 mg/cm³) than in open conditions (LD₅₀ > 0.353 mg/cm³). This suggests that toxicity is exerted largely in the vapor phase. Based on 24-h LD₅₀ values, the toxicity of caryophyllene oxide (0.00018 mg/cm³) was comparable with that of dichlorvos (0.00007 mg/cm³). In addition, thymol, camphene, α-pinene, p-cymene, and γ-terpinene showed good insecticidal activity (LD₅₀ = 0.012–0.195 mg/cm³). In repellency tests using 9 constituents of origanum oil, caryophyllene oxide showed complete repellency at 0.03 mg/cm². Hydrogenated monoterpenoids, such as thymol, α-pinene, carvacrol, and myrcene, elicited strong repellency at 0.03 and 0.006 mg/cm². Repellency depended on both time and concentration. These results indicate that origanum oil and its components could be potential candidates as a fumigant and repellent for managing T. castaneum adults.     

Antimicrobial activity of Thymus longicaulis C. Presl essential oil against respiratory pathogens

Thymus longicaulis C. Presl is a small aromatic perennial herb used as a traditional remedy for cold, flu and cough. Composition of the essential oil of T. longicaulis from Croatia and its in vitro antimicrobial activity against the most common respiratory pathogens were evaluated. The yield of essential oil obtained by hydrodistillation from aerial plant parts was 1.2%. According to the GC-MS analysis, a total of forty one compounds (99%) were identified. Thymol (46.3%), ??-terpinene (16.2%), thymyl methyl ether (11.4%), and p-cymene (9.4%) were the main components. Antimicrobial activity of the essential oil against six clinically isolated bacterial and yeast strains was determined using standard disc agar diffusion method and microdilution broth assay. The essential oil exhibited antimicrobial activity towards all tested respiratory pathogens. The most sensitive strains were Haemophilus influenzae and Streptococcus pneumoniae(MIC=0.78 mg/mL), while Staphylococcus aureus was the most resistant (MIC>25.00 mg/mL). Our results indicate that T. longicaulis essential oil could be effective against clinically relevant respiratory pathogens which have the ability to develop resistance to antimicrobial drugs.     

Growth and essential oil responses of <Emphasis Type="Italic">Nepeta</Emphasis> species to potassium humate and harvest time

Nepeta is a perennial herbal plant that belongs to the Lamiaceae mint family. Nepta has different species that are widely used in the agriculture, medicine, and pharmaceutical industries. A field experiment was conducted in 2015 and 2016 to determine the effects of potassium humate foliar application [0 (control) and 400 ppm] on growth, essential oil and constituents of three Nepta species [Nepeta cataria (catnip), Nepeta cataria var. citriodora (lemon catnip), and Nepeta grandiflora (giant catmint)] under Egyptian conditions. In all three species, the application of potassium humate increased growth indicators, essential oil content (%) and yield (mL/plant), and flavonoids in each of the two harvests. However, the height of giant catmint was significantly higher than that of lemon catnip, which was higher than that of catnip. Lemon catnip that received potassium humate and harvested second gave the highest essential oil content and yield. The major constituents were geraniol and nepetalactone in catnip; citronellol and geraniol in lemon catnip; and o-cymene, c-terpinene, p-cymene and carvacrol in giant catmint. The highest p-cymene in giant catmint, citronellol in lemon catnip, and geraniol in catnip were obtained from the application of potassium humate, while the highest o-cymene, c-terpinene and carvacrol in giant catmint, geraniol in lemon catnip, and nepetalactone in catnip were obtained from control plants. This study demonstrated the variations among species of nepeta, and how they respond to the application of potassium humate. The findings of this study can guide the customization of potassium humate applications to the three species for achieving desired growth and essential oil production outcomes.     

守宫木叶精油化学成分研究(简报)

守宫木（SauroPusandrogynus（L．）Merr．）为大朝科守宫木属植物,嫩茎枝叶可供食用。主产于南洋群岛和东南亚,印度、马来西亚、印度尼西亚、越南、泰国、菲律宾和柬埔寨等国均有分布;在我国云南、海南、广东、福建和四川等省（区）有零散栽培,亦有野生。近年我们大面积推广栽培,生产商品蔬菜"天绿香""',畅销于广州、深圳、上海、北京、武汉和香港等地。守宫木叶有微香,但迄今末见其精油化学成分研究的报道。本研究为改善"天绿香"的食用风味和叶的综合利用提供参考。l实验部分样品提取精油的守宫木叶采自本所大院内栽培的植株。用…     

Chemical Variability and Antioxidant Activity of Limbarda crithmoides L. Essential Oil from Corsica

The chemical compositions of 25 Corsican Limbarda crithmoides ssp. longifolia essential oils were investigated for the first time using GC‐FID, GC/MS, and NMR analyses. Altogether, 65 compounds were identified, accounting for 90.0–99.3% of the total oil compositions. The main components were p‐cymene ( 1 ; 15.1–34.6%), 3‐methoxy‐p‐cymenene ( 4 ; 11.8–28.5%), 2,5‐dimethoxy‐p‐cymenene ( 5 ; 5.9–16.4%), thymol methyl ether ( 6 ; 1.3–14.9%), α‐phellandrene ( 2 ; 0.9–11.9%), and α‐pinene ( 3 ; 0.2–13.4%). The chemical variability of the Corsican oil samples was studied using multivariate statistical analysis, which allowed the discrimination of two main clusters. A direct correlation between the water salinities of the plant locations and the chemical compositions of the L. crithmoides essential oils was evidenced. Indeed, essential oils rich in 1 (30.4–34.6%) were found in samples growing in the wetlands of the southern oriental coast, which exhibit high salinity levels (24.4±0.2–33.9±0.2 ppt), and essential oils with lower contents of 1 (15.1–27.3%) were isolated form samples growing in the wetlands of northern Corsica, which exhibit lower salinity levels (10.90±0.20–15.47±0.15 ppt). The antioxidant potential of L. crithmoides essential oil was also investigated, by assessing the DPPH^.‐ and ABTS^.+‐scavenging activities and the reducing power of ferric ions, and was found to be interesting. Moreover, using bioassay‐guided fractionation of the essential oil, a higher antioxidant activity was obtained for the oxygenated fraction and both ester and alcohol subfractions.