Salvia verbenaca L. essential oil: Variation of yield and composition according to collection site and phenophase

The effect of the collection sites and phenophase on yield and chemical composition of Salvia verbenaca essential oils was evaluated. The essential oil constituents were assessed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The highest essential oil yields were observed for samples of the higher semi-arid bioclimate and at the flowering period. Eighty-five volatile constituents were identified and their percentages varied significantly (p < 0.05) depending on the collection site and the phenological stage. According to the plants origin, essential oils were dominated by monoterpene hydrocarbons, oxygenated monoterpenes and sesquiterpene hydrocarbons. The monoterpene hydrocarbons (31.9%) predominate at the flowering stage whereas oxygenated sesquiterpenes (27.5%) at the early fruiting stage. The sesquiterpene hydrocarbons (28.2%) was the most represented chemical class at late fruiting. On the basis of GC-MS data, the major identified volatile constituents were viridiflorol (3.4–17.7%), α-pinene (0.7–15.9%), β-caryophyllene (1.0–15.3%) and p-cymene (1.3–14.2%). S. verbenaca contains a diversity of bioactive constituents which shows large variations as affected by the collection sites and phenophase.     

Screening the essential oil composition of wild Sicilian fennel

Fifty-six samples of wild fennel (Foeniculum vulgare Mill.) have been collected in different localities of Sicily and analysed for their content in seed essential oils. The GC-FID-MS analyses allowed identifying 78 compounds, representing more than 98% of the oils. Phenylpropanoids are the most highly represented components – 55 samples show estragole as the main compound ranging between 34 and 89%, while (E)-anethole is the other phenylpropanoid ranging between 0.1 and 36%, although it only reaches appreciable values in a few samples, largely being present below 1%. The oxygenated monoterpene, fenchone, a typical fennel oil component, has been found in all samples, in the 2–27% range; α-pinene (1–21%), limonene (1–17%) and γ-terpinene (<1–4%) were the monoterpene hydrocarbons found in all samples. Only one sample showed piperitenone oxide and limonene as main components, with 42 and 34%, respectively, and with the lack of any phenylpropanoid. Sesquiterpenes and others compounds class had only negligible values or were not detected in all samples. Statistical analyses allowed to single out five groups, reflecting the compositional differences of the essential oil profiles of the wild Sicilian fennel.     

Analysis of the volatile essential oils of Murraya koenigii and Pandanus latifolius

Using well-established techniques, samples were obtained of the volatile essential oils of the two types of curry leaf, Murraya koenigii and Pandanus latifolius. Both contained mainly terpenes, and M. koenigii produced less than 4% of other components with eight monoterpene hydrocarbons (ca 16%) and 17 sesquiterpene hydrocarbons (ca 80%) being obtained. The most important constituents of M. koenigii are β-caryophyllene, β-gurjunene, β-elemene, β-phellandrene and β-thujene. The volatile essential oil of P. latifolius also contained mainly sesquiterpene hydrocarbons (6–42%) but the only monoterpene was linalool (ca 6%). Nearly 2000 times the total quantity of aroma volatiles was produced by M. koenigii compared with P. latifolius, and this partly explains the observed stronger flavour potency of the former.     

Chemotaxonomic significance of the essential oils of 18 Ferula species (Apiaceae) from Iran

To evaluate the chemotaxonomic significance of the essential oils of 23 populations of 18 Iranian Ferula species, the chemical composition of the oils was investigated by GC/FID and GC/MS. Altogether, 84 constituents, representing 81.3-99.7% of the total composition of the oils, have been identified. The composition of six species of the genus, i.e., F. oopoda, F. foetida, F. behboudiana, F. diversivittata, F. galbaniflua, and F. hezarlalehzarica, has been reported for the first time. The main constituents identified were α-terpinyl acetate (73.3%), 2,3,4-trimethylthiophene (2; 49.0%), sabinene (75.3%), verbenone (5; 69.4%), β-pinene (59.0-66.3%), and (Z)-β-ocimene (41.7%). Cluster analysis (CA) of the percentage content of the essential oil components of the Ferula species resulted in the characterization of four groups, i.e., taxa containing either i) monoterpene hydrocarbons, ii) oxygenated monoterpenes, iii) organosulfur compounds, or iv) monoterpene, sesquiterpene, and aliphatic hydrocarbons as the principal classes of compounds. Based on the results obtained, the chemical independence of F. hirtella from F. szowitsiana and of F. galbaniflua from F. gummosa at the specific level was concluded and their positions as distinct species were confirmed. The chemotaxonomic relationships among the representatives of the genus Ferula have been discussed in detail.     

Chemical variability of the wood essential oil of Cedrus atlantica Manetti from Corsica

The composition of 48 samples of essential oil isolated from the wood of Cedrus atlantica growing in Corsica was investigated by GC (in combination with retention indices), GC/MS, and (13) C-NMR. Twenty-three compounds accounting for 73.9-96.0% of the oil composition were identified. The oils consisted mainly of monoterpene hydrocarbons and sesquiterpenes, in particular α-pinene (5; up to 79.4%), himachalol (4; up to 66.2%), β-pinene (up to 21.4%), β-himachalene (2; up to 19.3%), γ-himachalene (3; up to 11.0%), and α-himachalene (1; up to 10.9%). The 48 oil compositions were submitted to k-means partitioning and principal-component analysis, which allowed the distinction of two groups within the oil samples. The composition of Group I (44% of the samples) was dominated by 5, while the samples of Group II (56% of the samples) contained mainly 4.     

Isotope ratio by HRGC-MS of citrus Junos tanaka (yuzu) essential oils: m/z 137/136 of terpene hydrocarbons

The isotope ratios of monoterpene hydrocarbons in Citrus junos Tanaka (yuzu) essential oils from different origins were determined by ordinary high-resolution gas chromatography-mass spectrometry (HRGC-MS). Both intensities of the molecular mass peaks (m/z 136) and of the isotope peaks (m/z 137) of monoterpene hydrocarbons were measured by single-ion monitoring with an MS analysis. The isotope ratios (m/z 137/136) of the ten monoterpene hydrocarbons commonly contained in citrus essential oils, alpha-pinene, beta-pinene, sabinene, myrcene, alpha-phellandrene, alpha-terpinene, limonene, gamma-terpinene, beta-phellandrene and terpinolene, were determined in yuzu samples of the highest commercial quality from 42 different production districts. Statistical treatment of these data by the t-test and sign test revealed significant differences of the isotope effects in each yuzu sample. It is suggested that this technique will be applicable for evaluating the quality, genuineness and origin of citrus fruits and their products. The isotope fingerprints were also demonstrated in several citrus fruits other than the yuzu samples.     

Isotope ratio analysis by HRGC-MS of monoterpene hydrocarbons from citrus essential oils

The isotope ratio of monoterpene hydrocarbons in citrus essential oils of different origins was measured by ordinary high-resolution gas chromatography-mass spectrometry (HRGC-MS). The isotope ratio (Ir) was determined by the ratio of the isotope peak intensity (m/z 137) to the molecular mass peak intensity (m/z 136) of the monoterpene hydrocarbons. The accuracy of Ir was examined by measuring monoterpene hydrocarbon standards and 13C-labeled compounds. The isotope fingerprints based on the values of monoterpene hydrocarbons from lemon, lime and yuzu essential oils were determined. These citrus essential oils were also discriminated by a principal component analysis of their Ir data. The characteristic vectors showed that alpha-terpinene, beta-pinene and beta-phellandrene were important components for distinguishing between the citrus species. It is suggested that this technique will be applicable to evaluate the quality, genuineness and origin of citrus fruits and their products.     

Chemical Variability of the Needle Oil of Juniperus communis ssp. alpina from Corsica

The composition of 109 samples of essential oil isolated from the needles of Juniperus communis ssp. alpina growing wild in Corsica was investigated by GC (in combination with retention indices), GC/MS, and ¹³C‐NMR. Forty‐four compounds accounting for 86.7–96.7% of the oil were identified. The oils consisted mainly of monoterpene hydrocarbons, in particular, limonene (9.2–53.9%), β‐phellandrene (3.7–25.2%), α‐pinene (1.4–33.7%), and sabinene (0.1–33.6%). The 109 oil compositions were submitted to k‐means partitioning and principal component analysis, which allowed the distinction of two groups within the oil samples. The composition of the major group (92% of the samples) was dominated by limonene and β‐phellandrene, while the second group contained mainly sabinene beside limonene and β‐phellandrene.     

云南不同产地臭灵丹精油化学成分及抗菌活性

采用水蒸气蒸馏的方法,对采自云南4个不同地区（昆明,丽江,普洱,新平）的臭灵丹叶子进行挥发油提取,并利用GC MS和GC FID气相色谱联用技术分析其化学组成,分别从中鉴定出39、37、33、44个化合物。鉴定的化合物各占挥发油总量的9332% (昆明)、8057% (丽江)、9224% (普洱)和9385% (新平)。研究结果表明,采自这四个地区植物样品提取所得挥发油化学组成不尽相同：昆明产臭灵丹挥发油富含芳香族化合物(3806%);而从丽江和普洱样品中获得的挥发油化学成分以倍半萜（分别为1989%和4465%）和氧化倍半萜（分别为4085%和3511%）为主;非氧化单萜和非氧化倍半萜化合物（分别为4223%和3325%）则是新平产臭灵丹挥发油的主要化合物类型。同时,对这些不同产地的臭灵丹挥发油也进行了抗菌活性测试。从以上实验研究结果推测环境差异是影响臭灵丹挥发油化学组成差异的重要因素,而不同的化学组成可能是导致4种样品抗菌敏感程度不同的原因。     

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%) and γ-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 β-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 γ-terpinene, α-terpinene, p-cymene and terpinolene which previously were identified as potential antioxidants.     

In-vitro antimicrobial activity and chemical composition of Sardinian Thymus essential oils

Essential oils and their components are becoming increasingly popular as naturally occurring antimicrobial agents. In this work the chemical composition and the antimicrobial properties of Thymus essential oils and of their main components were determined. Three essential oils obtained from different species of Thymus growing wild in Sardinia and a commercial sample of Thymus capitatus oil were analysed. The essential oil components were identified by GC/MS analysis. The antimicrobial activity of the oils and components was determined against a panel of standard reference strains and multiple strains of food-derived spoilage and pathogenic bacteria, using a broth microdilution method. The GC/MS analysis showed that the major constituents of the oils were monoterpene hydrocarbons and phenolic monoterpenes, but the concentration of these compounds varied greatly among the oils examined. The results of the antimicrobial assay showed that essential oils extracted from Sardinian Thymus species have an antimicrobial activity comparable to the one observed in other thyme oils. It seems also confirmed that the antimicrobial properties of thyme essential oils are mainly related to their high phenolic content. Among the single compounds tested carvacrol and thymol turned out to be the most efficient against both reference strains and food-derived bacteria. The results of this study confirmed the possibility of using thyme essential oils or some of their components in food systems to prevent the growth of foodborne bacteria and extend the shelf-life of processed foods.     

Chemical composition and intraspecific variability of the essential oils of five populations of Hypericum triquetrifolium Turra growing in North Tunisia

The chemical composition of the essential oils of five populations of Hypericum triquetrifolium Turra from Tunisia and their intraspecific variability were analyzed in detail by GC/MS. One hundred seventy-four compounds were identified, representing averages of 87.9 to 98.7% of the oil composition. The components are represented here by homologous series of monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpenes hydrocarbons, oxygenated sesquiterpenes, non-terpenic hydrocarbons, and others. Sesquiterpene hydrocarbons were the most abundant chemical compounds. Multivariate chemometric techniques, such as cluster analysis (CA) and principal-component analysis (PCA), were used to characterize the samples according to the geographical origin. By statistical analysis, the analyzed populations were classified into four chemotype groups.     

A comparative study of Scalesia species (Asteraceae) by gas chromatographic analysis of the monoterpene hydrocarbons of their essential oils

ADSERSEN, A. & SVENDSEN, A. B., 1986. A comparative study of Scalesia species (Asteraceae) by gas chromatographic analysis of the monoterpene hydrocarbons of their essential oils. The monoterpene hydrocarbons of the essential oils of 13 species of Scalesia , Asteraceae, endemic to the Galapagos Islands, were analysed by gas chromatography to determine whether the composition of these compounds could show any characteristics for the various species. Marked differences in the monoterpene hydrocarbon patterns of the Scalesia species investigated were observed. Whereas a-pinene was usually found in amounts of 30–50%, Scalesia villosa contained only 12%. Sabinene usually occurred in amounts of 10-1.5%, but S. divisa and S. affinis contained about twice as much. The limonene content was usually less than 1%, but S. microcephala, S. baurii and S. affinis contained amounts varying from about 2% to 9.5%.     

A Comparative GC/MS Analysis of Citrus Essential Oils: Unveiling the Potential Benefits of Herb-Drug Interactions in Preventing Paracetamol-Induced Hepatotoxicity

Our study aimed to test the potential of Citrus oils in protecting against paracetamol (PAR)-induced hepatotoxicity. The essential oils of Pineapple sweet orange (OO), Murcott mandarin (MO), Red grapefruit (GO), and Oval kumquat (KO) were investigated using gas chromatography coupled with mass spectrometry (GC/MS). Twenty-seven compounds were identified, with monoterpene hydrocarbons being abundant class. d-Limonene had the highest percentage (92.98 %, 92.82 %, 89.75 %, and 94.46 % in OO, MO, GO, and KO, respectively). Hierarchical cluster analysis (HCA) and principal components analysis (PCA) revealed that octanal, linalool, germacrene D, and d-limonene were the principal discriminatory metabolites that segregated the samples into three distinct clusters. In vitro antioxidant capacities were ranged from 1.2–12.27, 1.79–5.91, and 235.05–585.28 μM Trolox eq/mg oil for 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic (ABTS), ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC), respectively. In vivo, citrus oils exhibited a significant reduction in alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and nitric oxide (NO). Additionally, there was an increase in glutathione reductase (GSH), and the liver architecture was nearly normal. Molecular docking revealed that d-limonene exhibited a good inhibitory interaction with cytochrome P450 (CYP450) isoforms 1A2, 3A4, and 2E1, with binding energies of −6.17, −4.51, and −5.61 kcal/mol, respectively.     

Investigations on the spontaneous emitted and hydrodistilled volatiles of Platycladus orientalis (L.) Franco grown in four different biogeographic zones of Jordan

The essential oil of the fresh leaves of Platycladus orientalis (L.), grown in four different biogeographic zones of Jordan,- (the Mediterranean, Irano-Turanian, Saharo-Arabian, and Sudanian penetration) -, were obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography-mass-spectrometry (GC/MS). The actual composition of the spontaneous emitted volatiles was obtained using the solid-phase-micro-extraction (SPME) method and investigated using the same chromatographic and spectroscopic methods. Hydrocarbon monoterpenes dominated the hydrodistilled oils and emissions of all regions. Bicyclic monoterpenes (sabinene, α-pinene, and α-thujene) and monocyclic α-terpinene were detected as the major constituents of the oils and emissions. Additionally, hierarchical cluster analysis (HCA) revealed that the clustering is based on the region of collection rather than the applied methodology. Differences were observed in the quantity of the obtained oils (P-values <0.01); the highest amount of volatile oil was obtained from samples grown in the Irano-Turanian biogeographic zone.     

Identification and characterization of volatile components of the Japanese sour citrus fruit Citrus nagato-yuzukichi Tanaka

A total of 39 aroma compounds were detected in the essential oil of Citrus nagato-yuzukichi Tanaka (nagato-yuzukichi) by gas chromatography-mass spectrometry (GC-MS). The essential oil was characterized by a high percentage of monoterpene hydrocarbons (12 components, 90.52%). The composition pattern of essential oil in C. nagato-yuzukichi was fairly similar to that of Citrus sudachi Hort. ex Shirai (Sudachi). Principal component analysis (PCA) of data obtained with an electronic nose indicated a variation of each oil along PC1. The oils of Citrus junos Tanaka (Yuzu) and Citrus sphaerocarpa Tanaka (Kabosu) showed a clear upward displacement as compared with those of C. nagato-yuzukichi and C. sudachi. However, in PC2, the oils of C. nagato-yuzukichi and C. sudachi showed a displacement in a negative direction and a positive one respectively.     

Autooxidation of a mixture of lemon essential oils,methyl linolenoate,and methyl oleinate

Stability of components of a mixture of methyl linolenoate and methyl oleinate with two lemon (Citrus limon L.) essential oils in hexane during their autooxidation in light was studied by gas chromatography. The essential oils differed by their quantitative ratio of components: the single-fold (1x) oil contained approximately 90% monoterpene hydrocarbons and 1.47% citral, whereas the proportions of hydrocarbons and citral in the tenfold (10x) oil were approximately 60 and 18.32%, respectively. The concentration and composition of essential oils influence the rates of fatty-acid oxidation and fatty-acid peroxide cleavage. The 1x lemon oil inhibited the oxidation of methyl linolenoate and methyl oleinate, whereas the 10x oil accelerated these processes. The distinctions in the resistance of the major components of lemon essential oil to oxidation, which are determined by their composition and antioxidant properties of unsaturated fatty acids, were revealed.     

Constituents of the essential oil of a new chemotype of Elsholtzia strobilifera Benth.

The composition of the essential oil from a new chemotype of Elsholtzia strobilifera Benth. collected from sub-alpine region of central Himalaya, India, has been investigated by Gas Chromatography and Gas Chromatography–Mass Spectrometry. The GC of the oil revealed the presence of more than 50 constituents, of which neral (18.3%) and geranial (29.9%) were found to be the major compounds and an absence of monoterpene hydrocarbons. Acylfuran derivatives, the specific chemical markers of the essential oils from the genus Elsholtzia were not detected.     

Chemical composition of the essential oils of ripe berries of Juniperus oxycedrus L., growing wild in Kosovo

The main objective of this work was to study the essential oil composition of ripe Juniperus oxycedrus L. berries and its natural variation among wild populations in Kosovo. Essential oil was analysed using GC-FID and GC–MS. Plant materials were collected from five locations in Kosovo in August and September of 2011. In total, twenty-seven compounds were identified in the essential oils. The main components were β-myrcene (45.5–56.9%), α-pinene (10.2–36.6%), dl-limonene (3.6–13.8%) and germacrene D (1.7–8.7%). Of the total identified compounds, monoterpenes constituted the highest percentage of all components (70.24–88.22%), followed by oxygenated sesquiterpenes (4.9–11.4%), sesquiterpenes (3.5–11.0%), oxygenated monoterpenes (0.2–2.7%) and oxygenated diterpenes (0.0–1.7). Hierarchical Cluster Analysis (HCA) and Principal Component Analyses (PCA) were used to identify any geographical variations in essential oil composition. Statistical analysis suggests that the clustering of populations is not related to their geographic location, but rather seemed to be linked to local selective forces acting on chemotype diversity.     

Essential‐Oil Composition of Helichrysum italicum (Roth) G.Don ssp. italicum from Elba Island (Tuscany,Italy)

The composition of 21 essential‐oil samples isolated from Helichrysum italicum collected in seven locations of Elba Island (Tuscany, Italy), characterized by different soil types, during three different periods (January, May, and October 2010) was determined by GC‐FID and GC/EI‐MS analyses. In total, 115 components were identified, representing 96.8–99.8% of the oil composition. The oils were characterized by a high content of oxygenated monoterpenes (38.6–62.7%), while monoterpene and sesquiterpene hydrocarbons accounted for 2.3–41.9 and 5.1–20.1% of the identified constituents, respectively. The main oxygenated derivatives were nerol (2.8–12.8%) and its ester derivative neryl acetate (5.6–45.9%). To compare the chemical variability of the species within Elba Island and between the island and other localities within the Mediterranean area, studied previously, multivariate statistical analysis was performed. The results obtained showed a difference in the composition of the essential oils of H. italicum from Elba Island, mainly due to the environment where the plant grows, and, in particular, to the soil type. These hypotheses were further confirmed by the comparison of these oils with essential oils obtained from H. italicum collected on other islands of the Tuscan archipelago.