Essential oil chemical diversity of twenty Iranian Origanum vulgare L. subsp. viride populations

Origanum vulgare L. belonging to the Lamiaceae family, commonly known as oregano, is one of the most traded and consumed medicinal plants worldwide. It is a rich natural source of specialized metabolites including essential oils. The present study is the first comprehensive account of the essential oil profile of wild O. vulgare subsp. viride plants in Iran. Twenty native populations from four provinces of northern Iran were investigated for the content and composition of essential oils. Essential oil contents were found to vary from 0.1 to 0.5% (v/w) based on dry weight. Analysis of these oils by GC-FID and GC-MS resulted in a total of forty-nine constituents, representing 96.2–99.7% of the total compositions. The subsequent classification of the studied populations by multivariate statistical procedures characterized four chemotypes: i) γ-terpinene/p-cymene; ii) linalool/α-phellandrene; iii) sabinene; and iv) carvacrol/trans-caryophyllene. These data may be useful in the future selection of populations comprising specific chemical characteristics for industrial purposes, and furthermore contribute beneficial information for developing conservation strategies, domestication and breeding programs of Iranian O. vulgare subsp. viride germplasm.     

Chemical Diversity of Wild Growing Origanum majorana in Cyprus

The present work aims at tracing the essential‐oil diversity of wild growing Origanum majorana plants in Cyprus. The study of six populations scattered over the western part of the island has shown that the essential oils were rich either in trans‐sabinene hydrate/terpinen‐4‐ol or in α‐terpineol/trans‐sabinene hydrate. The former oil type is more common and responsible for the typical marjoram odor of the plants. The comparison of our results with published data concerning wild and cultivated O. majorana showed that the oil composition of the Cypriot populations had not been reported from wild plants from other parts of the Mediterranean region, while it is very common among the cultivated plants. Thus, it seems probable that the nowadays cultivated marjoram may originate from Cypriot wild populations.     

Chemotype Diversity of Indigenous Dalmatian Sage (Salvia officinalis L.) Populations in Montenegro

To identify how many chemotypes of Salvia officinalis exist in Montenegro, the chemical composition of the essential oils of 12 wild‐growing populations was determined by GC‐FID and GC/MS analyses. Among the 40 identified constituents, the most abundant were cis‐thujone (16.98–40.35%), camphor (12.75–35.37%), 1,8‐cineol (6.40–12.06%), trans‐thujone (1.5–10.35%), camphene (2.26–9.97%), borneol (0.97–8.81%), viridiflorol (3.46–7.8%), limonene (1.8–6.47%), α‐pinene (1.59–5.46%), and α‐humulene (1.77–5.02%). The composition of the essential oils under study did not meet the ISO 9909 requirements, while the oils of populations P02–P04, P09, and P10 complied with the German Drug Codex. A few of the main essential‐oil constituents appeared to be highly intercorrelated. Strong positive correlations were observed between α‐pinene and camphene, camphene and camphor, as well as between cis‐thujone and trans‐thujone. Strong negative correlations were evidenced between cis‐thujone and α‐pinene, cis‐thujone and champhene, cis‐thujone and camphor, as well as between trans‐thujone and camphene. Multivariate analyses allowed the grouping of the populations into three distinct chemotypes, i.e., Chemotype A, rich in total thujones, Chemotype B, with intermediate contents of thujones, α‐pinene, camphene, and camphor and high borneol contents, and Chemotype C, rich in camphor, camphene, and α‐pinene. The chemotypes did not significantly differ in the total essential‐oil content and the cis/trans‐thujone ratio.     

Chemical composition of volatiles emitted by Ziziphus jujuba during different growth stages

The volatiles emitted in vivo by different organs (leaf, bud flower, flower, green and red fruits) of Ziziphus jujuba were analysed using HS-SPME-GC/MS. A total of 144 compounds were identified corresponding to 94.6–99.4% of the whole aroma profile of jujube samples. The main constituents detected were (E, E)-α-farnesene, (E)-β-ocimene, perillene, γ-terpinene, cis-sabinene-hydrate, trans-sabinene-hydrate and 4-terpineol. The SPME analyses of the collected samples showed different patterns of emission and can contribute to understand their ecological interactions and fruit production management.     

Variation in essential oil composition of Leonotis leonurus,an important medicinal plant in South Africa

Leonotis leonurus widely used by traditional healers in southern Africa for treatment of various ailments, is well known for its reported psychoactive properties. The present study was undertaken to investigate the variation in essential oil composition between geographically distinct populations of L. leonurus in South Africa using gas chromatography. Plant material (n = 50) was collected from three provinces of South Africa. Essential oils of the aerial parts were obtained by hydrodistillation and analysed using one and two dimensional gas chromatography. Twenty-six compounds accounted for more than 80% of the total composition of the oil. Eight major constituents in the oil, representing about 50% of the total oil composition, were identified by both GC–MS–FID and GCxGC–ToF–MS. These major compounds were trans-β-ocimene (0.1–5.0%), cis-β-ocimene (0.1–31.5%), β-caryophyllene (0.3–15.0%), caryophyllene oxide (0.1–5.0%), α-humulene (0.4–18.2%), γ-elemene (0.4–10.6%), α-cubebene (0.2–12.0%) and germacrene D (0.1–22.1%). Marked similarities exist in the essential oil composition between populations; differences are mostly quantitative when determined by GC–MS–FID, while GCxGC–ToF–MS data reveals both quantitative and qualitative differences.Untargeted multivariate analysis was performed using SIMCA-P + 14.0 PCA and OPLS-DA methods, identifying two distinct clusters, inland and coastal populations.     

Aroma Profile of Two Populations of Salvia verbenaca Collected from Two Bio‐Geographical Zones from Jordan

The aroma emitted from the different organs of two Salvia verbenaca L. populations from Jordan were extracted by Solid Phase Micro‐Extraction (SPME) and then analyzed by GC/MS. The emission profile of the stem, leaf and sepal samples from the Mediterranean zone (Al‐Salt) was dominated by monoterpene hydrocarbons (68.0 %, 33.7 %, and 42.2 %, respectively). The emission profile of flowering parts including pre‐flowering buds, fully expanded flowers and petals was dominated by oxygenated monoterpenes (58.6 %, 59.3 % and 87.1 %, respectively). The major constituent detected in these organs was trans‐sabinene hydrate acetate (range 14.5 %–87.0 %). On the other hand, samples collected from Irano‐Turanian zone showed different emission patterns. While the stems, leaves and petal emissions were dominated by sesquiterpene hydrocarbons (54.9 %, 76.8 % and 52.6 %, respectively), monoterpene hydrocarbons dominated the emission profiles of the pre‐flowering buds (75.1 %) and fully expanded flowers (73.6 %). Petals emissions were characterized by high concentrations of oxygenated monoterpenes (58.8 %). Notably, trans‐sabinene hydrate dominated most organs emissions except for leaves (range 20.0 %–58.8 %). Principle Component Analysis (PCA) and Cluster Analysis (CA) revealed two different clusters related to the two different geographical zones. The current investigation revealed two ecotypes of S. verbenaca that could result in two different chemotypes. Trans‐sabinene hydrate acetate and trans‐sabinene hydrate are suggested compounds for identifying these two chemotypes.     

High Diversity of Indigenous Populations of Dalmatian Sage (Salvia officinalis L.) in Essential‐Oil Composition

Essential oils of 25 indigenous populations of Dalmatian sage (Salvia officinalis L.) that represent nearly half of native distribution area of the species were analyzed. Plantlets collected from wild populations were grown in the same field under the same environmental conditions and then sampled for essential‐oil analysis. The yield of essential oil ranged from 1.93 to 3.70% with average of 2.83%. Among the 62 compounds detected, eight (cis‐thujone, camphor, trans‐thujone, 1,8‐cineole, β‐pinene, camphene, borneol, and bornyl acetate) formed 78.13–87.33% of essential oils of individual populations. Strong positive correlations were observed between camphor and β‐pinene, β‐pinene and borneol, as well as between borneol and bornyl acetate. The strongest negative correlation was detected between camphor and trans‐thujone. Principal component analysis (PCA) on the basis of eight main compounds showed that first main component separated populations with high thujone content, from those rich in camphor, while the second component separated populations rich in cis‐thujone from those rich in trans‐thujone. Cluster analysis (CA) led to the identification of three chemotypes of S. officinalis populations: cis‐thujone; trans‐tujone, and camphor/β‐pinene/borneol/bornyl acetate. We propose that differences in essential oils of 25 populations are mostly genetically controlled, since potential environmental factors were controlled in this study.     

Essential Oils and Chemical Diversity of Southeast European Populations of Salvia officinalis L.

The essential oils of 25 populations of Dalmatian sage (Salvia officinalis L.) from nine Balkan countries, including 17 indigenous populations (representing almost the entire native distribution area) and eight non‐indigenous (cultivated or naturalized) populations were analyzed. Their essential‐oil yield ranged from 0.25 to 3.48%. Within the total of 80 detected compounds, ten (β‐pinene, 1,8‐cineole, cis‐thujone, trans‐thujone, camphor, borneol, trans‐caryophyllene, α‐humulene, viridiflorol, and manool) represented 42.60 to 85.70% of the components in the analyzed essential oils. Strong positive correlations were observed between the contents of trans‐caryophyllene and α‐humulene, α‐humulene and viridiflorol, and viridiflorol and manool. Principal component analysis (PCA) on the basis of the contents of the ten main compounds showed that four principal components had an eigenvalue greater than 1 and explained 79.87% of the total variation. Performing cluster analysis (CA), the sage populations could be grouped into four distinct chemotypes (A–D). The essential oils of 14 out of the 25 populations of Dalmatian sage belonged to Chemotype A and were rich in cis‐thujone and camphor, with low contents of trans‐thujone. The correlation between the essential‐oil composition and geographic variables of the indigenous populations was not significant; hence, the similarities in the essential‐oil profile among populations could not be explained by the physical proximity of the populations. Additionally, the southeastern populations tended to have higher EO yields than the northwestern ones.     

Structure of the cyclic peptide [W8S]contryphan Vn: effect of the tryptophan/serine substitution on trans–cis proline isomerization

The structural characterization of [W8S]contryphan Vn, an analogue of Contryphan Vn with tryptophan 8 substituted with a serine residue (W8S), was performed by NMR spectroscopy, molecular dynamics simulations and fluorescence spectroscopy. Contryphan Vn, a bioactive cyclic peptide from the venom of the cone snail Conus ventricosus, contains an S–S bridge between two cysteines and a d-tryptophan. Like other Contryphans, [W8S]contryphan Vn has proline 7 isomerized trans, while the proline 4 has nearly equivalent populations of cis and trans configurations. The thermodynamic and kinetic parameters of the trans–cis isomerization of proline 4 were measured. The isomers of [W8S]contryphan Vn with proline 4 in cis and trans show structural differences. The absence of the salt bridge between the same Asp2 and Lys6, present in Contryphan Vn, may be attributed to the lack of the hydrophobic side chain of Trp8 where it likely protects the electrostatic interactions. These results may contribute to identifying, in these cyclic peptides, the structural determinants of the mechanism of proline trans–cis isomerization, this being also an important step in protein folding.     

Essential oil variability within and among populations of Cunila incisa Benth.

To evaluate the intra- and interpopulational variability of volatile compounds in Cunila incisa, 72 samples representing 12 populations, were collected all over the distribution area of the species in Rio Grande do Sul State. The samples were extracted by steam distillation and analyzed using GC and GC–MS. A total of 19 volatile compounds were detected and identified. In average, the main compounds were 1,8-cineole, α-terpineol, p-cymene, sabinene, terpinene-4-ol, and γ-terpinene. Negative correlation was detected between the concentrations of 1,8-cineole and α-terpineol. Significant variation in the concentration of volatile compounds was detected within and among populations. Multivariate analysis of volatile oil composition identified three groups. Most populations exhibited low intra-populational variation indicating foundation effect. Relation between geographic distribution and chemical composition was observed.     

The inflorescence and leaf essential oils of Tanacetum vulgare L. var. vulgare growing wild in Lithuania

Forty samples of inflorescences and leaves of wild Tanacetum vulgare L. var. vulgare were collected in 20 habitats from Lithuania. The essential oils were analyzed by GC and GC/MS. The 57 identified compounds in the oils made up 80.7–99.6%. According to the cluster analysis the volatile oils were divided into four groups with 1,8-cineole (23.6–46.3%, 11 oils), trans-thujone (35.7–78.4%, 6 samples), camphor (19.8–61.8%, 17 oils) and myrtenol (13.1–24.9%, 6 samples) as main constituents. The inflorescences and leaves of tansy plants formed the oils with the same dominating constituent in 15 of the 20 habitats investigated. The leaves in five localities produced oils of the 1,8-cineole chemotype, while the inflorescences biosynthesized oils of the camphor type in three habitats and of the myrtenol type in two habitats. Amounts of the 1,8-cineole in all leaf oils were greater than that in inflorescence oils of the plants from the same locality. An opposite correlation was determined for camphor, myrtenol, cis- and trans-thujone. The myrtenol chemotype was not noticed earlier in the essential oils of T. vulgare.     

Effects of cis and trans regulatory variations on the expression divergence of heat shock response genes between yeast strains

Phenotypic variation among individuals in a population can be due to DNA sequence variation in protein coding regions or in regulatory elements. Recently, many studies have indicated that mutations in regulatory elements may be the major cause of phenotypic evolution. However, the mechanisms for evolutionary changes in gene expression are still not well understood. Here, we studied the relative roles of cis and trans regulatory changes in Saccharomyces cerevisiae cells to cope with heat stress. It has been found that the expression level of ~ 300 genes was induced at least two fold and that of ~ 500 genes was repressed at least two fold in response to heat shock. From the former set of genes, we randomly selected 65 genes that showed polymorphism(s) between the BY and RM strains for pyrosequencing analysis to explore the relative contributions of cis and trans regulatory variations to the expression divergence between BY and RM. Our data indicated that the expression divergence between BY and RM was mainly due to trans regulatory variations under either the normal condition or the heat stress condition. However, the relative contribution of trans regulatory variation was decreased from 76.9% to 61.5% after the heat shock stress. These results indicated that the cis regulatory variation may play an important role in the adaption to heat stress. In our data, 43.1% (28 genes) of the 65 genes showed the same trend of cis or trans variation effect after the heat shock stress, 35.4% (23 genes) showed an increased cis variation effect and 21.5% (14 genes) showed an increased trans variation effect after the heat shock stress. Thus, our data give insights into the relative roles of cis and trans variations in response to heat shock in yeast.     

The leaf oil terpene composition of Juniperus occidentalis

The chemical composition of the volatile oil of 10 trees each of two Oregon populations of the western juniper was determined by a computerized GC-MS method. The identity of the major components, sabinene, α-pinene, α- and γ-terpinene, p-cymene, limonene, terpinen-4-ol and bornyl acetate was confirmed. In addition, tricyclene, α-thujene, camphene, β-pinene, α- and β-phellandrene, car-3-ene, trans-ocimene, linalool oxide, terpinolene, trans-sabinene hydrate, camphor, camphene hydrate, borneol, α-terpineol, p-cymenol, methyl citronellate, citronellyl acetate, carvacrol, cuminic aldehyde, β-bourbonene, several cadinene and cadinol isomers, elemol, γ-, β- and α-eudesmol, and manoyl oxide were identified. Santene, citronellol, and aromatic ethers of the safrole-eugenol type were not found. Tree-to-tree variability of the relative percentages of these terpenes was fairly large and chemosystematic implications are discussed briefly.     

Influence of growth phase on the essential oil composition of Hyptis suaveolens

The chemical composition of the essential oils of seven populations of Hyptis suaveolens in vegetative, flowering and fruiting stages and their interpopulation variability were investigated by GC–MS. Sabinene, limonene, 1,8-cineole, (E)-caryophyllene and spathulenol were the principal constituents. The results from the chemical analysis were submitted to Principal Component and Chemometric Cluster Analysis which allowed five groups of populations to be distinguished with respect to the stage of growth and high content of bicyclogermacrene/terpin-4-ol, sabinene, 1,8-cineole/spathulenol, limonene/γ-terpinene and spathulenol/(E)-caryophyllene. Pattern of geographic-variation in essential oil composition indicated that monoterpene hydrocarbons were mainly produced in plants from sampling sites located in higher latitudes and altitudes regardless of the phase of growth, while sesquiterpenes were mainly produced in fruiting samples grown at lower ones. The Canonical Correlation Analysis between the soil sampling sites with the populations revealed a significant relationship between oil components and edaphic factors. Sesquiterpenes and potential acidity, Al, and Al saturation load fairly strong onto the first canonical variate and are related to fruiting samples collected at lower latitudes. On the other hand, monoterpene hydrocarbons are strongly related to chemical balance in soils (P, Zn, Cu, Mn, base saturation, neutral pH), which is related to the vegetative/flowering sampling at higher latitudes.     

Seasonal variations in trans-2-hexenal and linolenic acid in homogenates of Thea sinensis leaves

The seasonal variations in the amounts of C₆-volatile components cis-3-hexenal trans-2-hexenal n-hexanal) and their precursors (linoleic and linolenic acid) in homogenates of Thea sinensis leaves were quantitatively analyzed throughout the year. Formation of trans-2-hexenal began in the middle of April and reached a maximum during July. Towards autumn the aldehyde gradually decreased and, in winter (December to March), was virtually absent. The levels of cis-3-hexenol remained constant during May–December. cis-3-Hexenal showed a similar variation pattern to that of trans-2-hexenal. The major fatty acids in the leaves were palmitic, palmitoleic, oleic, linoleic and linolenic acid, and occurred in non-ionic lipids and phospholipid fractions. The amounts of linoleic and linolenic acid did not show any marked variation except for a big peak in October.     

Variation in sex pheromone composition in large fruit-tree tortrix Archips podana Scop. (Lepidoptera: Tortricidae)

Variation in sex pheromone composition was studied in large fruit-tree tortrix. The pheromone contained cis-11-tetradecenyl acetate and trans-11-tetradecenyl acetate as macrocomponents as well as microcomponents cis-11-tetradecenol and trans-11-tetradecenol with the prevalence of cis-11-tetradecenyl acetate and cis-11-tetradecenol. The pheromone composition depended in part on the genotype of the male parent. Inbreeding increased the proportion of trans-11-tetradecenyl acetate and trans-11-tetradecenol.     

Chemical Polymorphism of Essential Oils of Artemisia vulgaris Growing Wild in Lithuania

Compositional variability of mugwort (Artemisia vulgaris L.) essential oils has been investigated in the study. Plant material (over ground parts at full flowering stage) was collected from forty‐four wild populations in Lithuania. The oils from aerial parts were obtained by hydrodistillation and analyzed by GC(FID) and GC/MS. In total, up to 111 components were determined in the oils. As the major constituents were found: sabinene, 1,8‐cineole, artemisia ketone, both thujone isomers, camphor, cis‐chrysanthenyl acetate, davanone and davanone B. The compositional data were subjected to statistical analysis. The application of PCA (Principal Component Analysis) and AHC (Agglomerative Hierarchical Clustering) allowed grouping the oils into six clusters. AHC permitted to distinguish an artemisia ketone chemotype, which, to the best of our knowledge, is very scarce. Additionally, two rare cis‐chrysanthenyl acetate and sabinene oil types were determined for the plants growing in Lithuania. Besides, davanone was found for the first time as a principal component in mugwort oils. The performed study revealed significant chemical polymorphism of essential oils in mugwort plants native to Lithuania; it has expanded our chemotaxonomic knowledge both of A. vulgaris species and Artemisia genus.     

A comparison between CLNA and CLA effects on body fat, serum parameters and liver composition

The potential of conjugated linoleic acid (CLA) as an anti-obesity molecule for humans is still a matter for debate. Thus, a great deal of scientific work is focussed on the research of new effective molecules without deleterious effects on health. The aim of the present work was to analyse the effects of jacaranda seed oil, rich in a conjugated linolenic acid (CLNA), jacaric acid (cis-8,trans-10,cis-12), on body fat, serum parameters and liver composition in rats, and to compare these effects with those oftrans-10,cis-12 CLA. Twenty-six male Wistar rats were divided into three groups fed with high-fat diets, supplemented or not (control group) with 0.5%trans-10,cis-12 CLA (CLA group) or 0.5% jacaric acid (CLNA group) for 7 weeks. No statistical differences in food intake or in final body weight were found. Whereas CLA reduced adipose tissue size, CLNA did not. Both CLA and CLNA significantly reduced non-HDL-cholesterol. In spite of a lack of significant changes in glucose and insulin levels, HOMA-IR index was significantly increased, as well as did non-esterified fatty acid levels in CLNA-fed rats. No changes in liver composition were observed. In conclusion, under our experimental conditions, jacaric acid, unlike CLA, does not show a body-fat lowering effect. Even though it leads to a healthy lipoprotein profile, it impairs insulin function. Consequently, it cannot be proposed as an anti-obesity molecule.