Chemical compositions of Casuarina equisetifolia L., Eucalyptus toreliana L. and Ficus elastica Roxb. ex Hornem cultivated in Nigeria

Essential oils were obtained by separate hydrodistillation of three different plants cultivated in Nigeria and analysed comprehensively for their constituents by means of gas chromatography (GC) and gas chromatography-mass spectrometry (GC–MS). The leaf essential oil of Casuarina equisetifolia L. (Casuarinaceae) comprised mainly of pentadecanal (32.0%) and 1,8-cineole (13.1%), with significant amounts of apiole (7.2%), α-phellandrene (7.0%) and α-terpinene (6.9%), while the fruit oil was dominated by caryophyllene-oxide (11.7%), trans-linalool oxide (11.5%), 1,8-cineole (9.7%), α-terpineol (8.8%) and α-pinene (8.5%). On the other hand, 1,8-cineole (39.4%) and α-terpinyl acetate (10.7%) occurred in large quantities in the essential oils of the leaf of Eucalyptus toreliana L. (Myrtaceae). The oil also features high levels of sabinene (5.9%), caryophyllene-oxide (4.7%) and α-pinene (4.2%). The main compounds identified in the leaf oil of Ficus elastica Roxb. ex Hornem. (Moraceae) were 6,10,14-trimethyl-2-pentadecanone (25.9%), geranyl acetone (9.9%), heneicosene (8.4%) and 1,8-cineole (8.2%).     

The effects of laurel (Laurus nobilis L.) on development of two mycorrhizal fungi

Hundreds of aromatic plant species are growing naturally around Mediterranean. Plant essential oils are incorporated in aromatic plant material and follow the litter fall. During litter degradation, the presence of essential oils can affect soil microorganisms. Mycorrhizal fungi have never been investigated so far under the presence of volatile oils. The aim of this study was to explore the effect of aromatic Laurus nobilis L. on development of two mycorrhizal species Glomus deserticola and Glomus intraradices. The response of fungi colonization and host growth were monitored under different concentrations of L. nobilis leaves and essential oil. The major compounds of L. nobilis essential oil were 1,8-cineole (49.6%), sabinene (7.8%), ??-pinene (6.0%), eugenole (5.6%), ??-terpinyl acetate (5.2%) and ??-pinene (5.1%). Both mycorrhizal fungi colonized successfully the host plants whose growth was positively influenced by mycorrhizal fungi. G. deserticola presented higher infection level than G. intraradices. The addition of L. nobilis leaves in the soil resulted in mycorrhiza inhibition. The level of inhibition was positively correlated with the added amount of aromatic leaves in the soil. The essential oil presented a little higher inhibition than the leaves. The presence of this aromatic plant in many different ecosystems could contribute in mycorrhiza inhibition and it is suggested, when it’s possible, reduction of laurel litter before reforestation programs.     

Chemical composition, antioxidant activity and inhibitory effects of essential oil of Eucalyptus teretecornis grown in north-western Himalaya against Alternaria alternata

The essential oil obtained from fresh leaves of Eucalyptus teretecornis (family Myrtaceae) was analysed by gas chromatography/mass spectrometry (GC/MS). Twenty eight compounds were identified and ??-pinene (22.55%), ??-pinene (22.50%), 1,8-cineole (19.84%), limonene (5.62%), ??-fenchol (3.10%), ??-phellandrene (2.90%), ??-eudesmol (2.66%) and 4-(2-methylcyclohex-1-enyl)-but-2-enal (2.34%) were the main components. The antifungal activity of the essential oil was assayed against Alternaria alternata using bioautography. Two main bioactive components namely a₁ (R _f ?=?0.27) and a₂ (R _f ?=?0.33) were observed that produced inhibition zone of 4?mm and 8?mm in diameter respectively. The minimum inhibitory amount (MIA) of a₁ and a₂ against A. alternata was determined as 28???g and 10???g, respectively using bioautography assay. Components corresponding to a₁ and a₂ were determined as ??-fenchol (oxygenated monoterpene) and ??-eudesmol (oxygenated sesquiterpene) respectively using GC/MS analysis. The antioxidant activity of the essential oil and its bioactive fraction was evaluated by DPPH radical scavenging assay, ??-carotene/linoleic acid bleaching assay, reducing power assay and metal chelating assay. In addition fraction of the essential oil that showed antioxidant activity was analyzed using GC/MS and ??-fenchol, 4-terpineol and carvacrol were the main components.     

Variation of Salvia fruticosa Essential Oils on the Island of Crete (Greece)

The essential oil content and composition of Salvia fruticosa (Greek sage) plants growing wild in 20 localities scattered on the island of Crete are studied. The results of our analyses have shown a noticeable variation in the essential oil content (ranging from 1.1 up to 5.1 %) and the amount of the four main oil components: 1,8-cineole (22.7 ? 64.2% of total oil), α-thujone (1.0 ? 19.2%) β-thujone (0.9 ? 25.6%) and camphor (0.8 ? 30.3%). Discriminant analysis revealed that the variation pattern of the essential oil content and the amount of the four main oil components is geographically related, following a W → E direction. Plants grown in Western Crete show a lower essential oil content and their oils are characterised by the predominance of 1,8-cineole. On the other hand, those collected from Eastern Crete exhibit higher values in essential oil content and their oils, besides 1,8-cineole, are rich in α- and β-thujone or camphor. Our findings are further discussed in relation to literature data.     

Essential oil composition of two yarrow taxonomic forms

Differences in essential oil composition of wild Achillea millefolium L., collected at five habitats in Lithuania, where plants with pink (f. rosea) and white (f. millefolium) flowers grow together, were reported. For the first time, oils of different plant organs (inflorescences and leaves) of both forms from every population were analysed in detail. Chemical analysis was performed by GC and GC-MS. The most predominant constituents of the oils were nerolidol (9.4–31.9%, in 11 out of 20 samples), caryophyllene oxide (8.4–23.0%, 4 leaf oils), ß-pinene (8.0–15.2%, 2 samples), eudesmol (11.8–15.8%, 2 leaf oils) and 1,8-cineole (11.9%, one inflorescence oil). Domination of nerolidol was mostly characteristic of A. millefolium f. rosea essential oils (in 8 out of 10 oils). The inflorescences biosynthesised markedly larger amounts of nerolidol and ß-pinene than those of the leaves. An opposite correlation was observed for caryophyllene oxide and eudesmol. Chamazulene (≤2.7%) was determined only in six oils. The 65 identified constituents made up 75.4–96.5% of the oils.     

Anti-fungal activity of essential oils of Ceylon Eucalyptus species for the control of Fusarium solani and Sclerotium rolfsii

The essential oils were extracted from the leaves of Eucalyptus microcorys, Eucalyptus grandis and Eucalyptus robusta which were grown in Sri Lanka and their major chemical compounds were determined. 1,8-Cineole and α-pinene were identified as major aroma compounds in these oils. In this study, the anti-fungal activity of essential oils of E. microcorys, E. grandis and E. robusta, ethanol extract of E. microcorys and 1,8-cineole were evaluated against Sclerotium rolfsii, a fungi responsible for leaf spot disease of indoor plants and Fusarium solani, a fungi responsible for dry rot diseases of potato by poisoned food technique, and minimum inhibitory concentrations (MICs) were determined. The essential oils from three Eucalyptus species showed significant inhibitory effect against S. rolfsii and F. solani than the ethanol extract of E. microcorys. Of treatments, the essential oil of E. grandis showed the best anti-fungal activity with the MIC values of less than 0.1% for S. rolfsii and 0.5% for F. solani. The MICs of the oils of E. microcorys and E. robusta were between 0.3–0.5% against S. rolfsii and 0.5–0.75% for F. solani. The 1,8-cineole did not exhibit inhibition activity as much of Eucalyptus essential oils and hence, it can be assumed that minor chemical components of the oils contribute to the growth inhibition of the tested fungi. This is the first report of anti-fungal activity of Sri Lankan oils of E. microcorys, E. grandis and E. robusta and ethanol extract of E. microcorys against S. rolfsii and F. solani. These findings would be useful for the designing of natural fungicide for agriculture- and food-based industries.     

Comparative analysis of volatiles from needles of five-needle pines of northern and eastern Eurasia

The chemical composition of essential oil samples from needles of six species of five-needle pines (Pinus pumila, Pinus sibirica, Pinus parviflora, Pinus armandii, Pinus koraiensis, and Pinus cembra) and one natural interspecific hybrid Pinus sibirica × Pinus pumila has been studied by the chromato-mass spectrometry method. Essential oils have been prepared by simultaneous steam distillation-extraction. The analysis of the samples?? composition showed that the main constituents of the essential oils were the following mono- and sesquiterpenic compounds: ??-pinene (5?C63%), camphene (0.7?C3.6%), ??-pinene (0.7?C7%), ??-myrcene (0.5?C3.4%), 3-carene (0?C16%), limonene (0.6?C7.9%), ??-phellandrene (0.7?C5.3%), terpinolene (0.4?C6.7%), bornyl acetate (0.2?C12%), ??-terpenyl acetate (0?C4.6%), caryophyllene (0.4?C24%), humulene (0.1?C4%), germacrene D (0.1?C24%), bicyclogermacrene (0.1?C3.6%), ??-cadinene (0.9?C2.3%), ??-cadinene (2.2?C6.1%), germacrene D-4-ol (0?C6.8%), T-cadinol (0.7?C2.9%), and ??-cadinol (0.7?C6.0%).     

Composition of essential oils from turkish Salvia species

The chemical composition of the essential oils from five Salvia species from Turkey was determined by GC. The species were S. candidissima, S. cryptantha, S. fruticosa, S. officinalis and S. tomentosa. 24, 22, 20, 19, and 22 components were identified, respectively, the major ones being β-pinene (candidissima), borneol (cryptantha), 1,8-cineole (fruticosa), camphor (officinalis) and β-pinene (tomentosa). α-Pinene in candidissima, camphor in cryptantha, α-thujone in officinalis and 1,8-cineole in tomentosa were the other important components.     

Chemical compositions,antimicrobial and herbicidal effects of essential oils isolated from Turkish Tanacetum aucheranum and Tanacetum chiliophyllum var. chiliophyllum

The chemical composition of essential oils isolated from the aerial parts by hydrodistillation of Turkish Tanacetum aucheranum and Tanacetum chiliophyllum var. chiliophyllum were analyzed by GC–MS. The oils contain similar major components. The major components of T. aucheranum oil were 1,8-cineole (23.8%), camphor (11.6%), terpinen-4-ol (7.2%), α-terpineol (6.5%), borneol (3.8%), (E)-thujone (3.2%), epi-α-cadinol (3.1%), and artemisia ketone (3.0%). Camphor (17.9%), 1,8-cineole (16.6%) and borneol (15.4%) were found to be predominant constituents in the oil of T. chiliophyllum. It is interesting to find that ester derivatives of dihydro-α-cyclogeranic acid (2,2,6-trimethylcyclohexylcarboxylate), dihydro-α-cyclogeranyl hexanoate (10.1%), dihydro-α-cyclogeranyl pentanoate (3.0%), dihydro-α-cyclogeranyl butanoate (2.1%) and dihydro-α-cyclogeranyl propionate (1.2%) are firstly found as chemotaxonomically important components in T. chiliophyllum oil. From these, dihydro-α-cyclogeranyl hexanoate was isolated on silica gel column chromatography and its structure was confirmed by spectroscopic methods. This is the first report on the occurrence of ester derivatives of dihydro-α-cyclogeranic acid in essential oils of Tanacetum species. The oils were also characterized to have relatively high amounts of oxygenated monoterpenes. Results of the antifungal testing by microbial growth inhibition assays showed that the oils completely inhibit the growth of 30 phytopathogenic fungi. However, their growth inhibition effects were lower than commercial benomyl. The oils tested for antibacterial activity against 33 bacterial strains showed a considerable antibacterial activity over a wide spectrum. Herbicidal effects of the oils on seed germination of Amaranthus retroflexus, Chenopodium album and Rumex crispus were also determined and the oils completely inhibited the seed germination and seedling growth of the plants.     

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.     

Association genetics of essential oil traits in <Emphasis Type="Italic">Eucalyptus loxophleba</Emphasis>: explaining variation in oil yield

York gum (Eucalyptus loxophleba Benth) is widely planted in semi-arid regions of Australia for the production of Eucalyptus oil, a mixture of terpenes dominated by the monoterpene 1,8-cineole. Increasing oil yield in this species would improve the profitability of this crop and enhance its use in sustainable land management systems in Australia. To this end, we sequenced ten structural genes in the terpene biosynthetic pathway of ~400 individuals of E. loxophleba. Of the 4353 allelic variants identified, 1347 had a minor allele frequency >0.01. These were associated with three key traits of essential oil yield (concentration of 1,8-cineole, α-pinene and total terpenes). Three variants associated with α-pinene, two with 1,8-cineole and eight with total terpenes (13 total). The variants were mostly located in introns of the final three biosynthetic steps of the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway (mcs, hds and hdr). Effect size varied from 2.7 to 6.8%, comparable to similar studies in forest trees. The cumulative effect size of the unlinked variants was 34.8% for total terpenes, although this is likely to be a high estimate. These results provide the basis for the development of molecular breeding methods for improving essential oil yield in this industrially important species.     

Simulation of Eucalyptus cinerea oil distillation: A study on optimization of 1,8-cineole production

Cineolic essential oils are used in medicinal, perfumery and flavour preparations. 1,8-Cineole, being an ecofriendly compound, has the potential to replace the ozone depleting industrial solvents. Optimized process parameters for hydrodistillation and production of essential oil enriched with 1,8-cineole from Eucalyptus cinerea grown in the mid-hills of western Himalaya, were reported. The effect of drying of the foliage prior to distillation with respect to oil composition and content was studied. The first order kinetic and Langmuir adsorption models were evaluated to simulate hydrodistillation of E. cinerea oil. The Langmuir model parameters that simulate the hydrodistillation process were determined. GCMS analysis revealed that the oil produced from fresh foliage contained higher 1,8-cineole content (84.4%) than the dried foliage (77.6%). The other major constituents were limonene and α-terpineol.     

Chemical Composition and In Vitro Cytotoxicity of Essential Oils from Leaves and Flowers of Callistemon citrinus from Western Himalayas

Background

Plant-based traditional system of medicine continues to play an important role in healthcare. In order to find new potent source of bioactive molecules, we studied the cytotoxic activity of the essential oils from the flowers and leaves of Callistemon citrinus. This is the first report on anticancer potential of essential oils of C. citrinus.

Methods

Cytotoxicity of essential oil was evaluated using sulfo-rhodamine B (SRB) assay against human lung carcinoma (A549), rat glioma (C-6), human colon cancer (Colo-205) and human cervical cancer (SiHa) cells. Apoptosis induction was evaluated by caspase-3/7 activity which was further confirmed by western blotting. Percentage cell apoptosis was determined by Annexin V based dead cell assay followed by DNA content as cell cycle analysis against A549 and C-6 cells. While 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was used to check the toxicity against normal human peripheral blood mononuclear cells (PBMCs), the immunomodulatory activity on mouse splenocytes was evaluated using SRB assay.

Results

The GC and GC-MS analysis of these essential oils revealed high content of α-pinene (32.3%), limonene (13.1%) and α-terpineol (14.6%) in leaf sample, whereas the flower oil was dominated by 1,8-cineole (36.6%) followed by α-pinene (29.7%). The leaf oil contained higher amount of monoterpene hydrocarbons (52.1%) and sesquiterpenoids (14%) as compared to flower oil (44.6% and 1.2%, respectively). However, the flower oil was predominant in oxygenated monoterpenes (43.5%). Although both leaf and flower oils showed highest cytotoxicity on A549 cells (61.4%±5.0 and 66.7%±2.2, respectively), only 100 μg/mL flower oil was significantly active against C-6 cells (69.1%±3.1). Interestingly, no toxicity was recorded on normal cells.

Conclusion

Higher concentration of 1,8-cineole and/or synergistic effect of the overall composition were probably responsible for the efficacy of flower and leaf oils against the tested cells. These oils may form potential source of natural anti-cancer compounds and play important role in human health.     

1,8-cineole and castor oil in sodium lauryl ether sulphate disrupt reproduction and ovarian tissue of Rhipicephalus (Boophilus) microplus

Essential and fixed oils have been researched as alternatives to chemical acaricides. The activity of volatile compounds from essential oils (1,8-cineole, citral and eugenol) at 1.0% (w/v) and fixed oil (castor oil) at 0.3% (w/v) dissolved in 2.0% (v/v) dimethyl sulfoxide (DMSO) + 0.2% (w/v) Tween 80^® was assessed against Rhipicephalus microplus using immersion tests. 1,8-cineole (29.0%) and castor oil (30.2%) had the highest reproductive inhibition rate. A second experiment was performed to verify the effect of the 1,8-cineole (10.0% w/v) and, or castor oil (0.3% w/v) on tick reproduction using different solubilizing agents. The highest reproductive inhibition was observed for the combination of 1,8-cineole/castor oil (94.1%) and 1,8-cineole in 2.0% (w/v) sodium lauryl ether sulphate (SLES) (92.8%). A third experiment showed morphological changes in R. microplus oocytes at different stages of development, as well as in pedicel cells. The most intense effects were observed when ticks were immersed in the formulation containing 1,8-cineole (10.0% w/v) and castor oil (0.3% w/v) dissolved in 2% (w/v) SLES. These findings highlight the potential of this formulation as an alternative for managing cattle ticks as their cytotoxic effects can reduce R. microplus reproductive success.     

Chemical Variability of Moroccan Myrtle Oil

Thirty-three oil samples isolated from aerial parts of Myrtus communis L. harvested in seven localities, from Northern to Central Morocco, have been analyzed by combination of chromatographic and spectroscopic techniques. The 33 compositions have been subjected to statistical analysis, hierarchical cluster analysis (HCA) and principal component analysis (PCA). Two groups have been differentiated on the basis of their myrtenyl acetate and α-pinene contents and each one was sub-divided in two sub-groups according to the contents of 1,8-cineole and linalool. The compositions of our 33 myrtle oil samples may be named as follow by their main components: sub-group IA (13/33): α-pinene/1,8-cineole/linalool; sub-group IB (6/33): 1,8-cineole/α-pinene; sub-group IIA (10/33): 1,8-cineole/myrtenyl acetate; sub-group IIB (4/33): myrtenyl acetate.     

Laurus novocanariensis essential oil: Seasonal variation and valorization

We investigated the qualitative and quantitative seasonal variation of the leaf and fruit oils of the Macaronesian endemism Laurus novocanariensis and their plant defensive potential. The monoterpene fraction dominated the leaf (74%) and berry essential oils (73–44%, ripe–unripe). The insect antifeedant effects of these oils were species- and season-dependent against the aphids (Myzus persicae and Rhopalosiphum padi). Overall, the biological effects of these oils correlated with the oxygenated terpene fraction. Among the pure components tested, β-caryophyllene and its oxide were strong antifeedants to Leptinotarsa decemlineata and Spodoptera littoralis. The aphids responded to β-ocimene, β-pinene, 1,8-cineole, linalool (antifeedants) and linalool oxide (attractive to M. persicae). The antifungal effects of the leaf oils on Fusarium spp. were season-dependent. β-Caryophyllene oxide proved to be a strong antifungal. L. novocanariensis oils inhibited Lactuca sativa germination and radicle elongation, the leaves being more effective. Linalool also inhibited seed germination.     

Comparative determination of the essential oil composition in Bulgarian endemic plant Achillea thracica Velen. during the process of ex situ conservation

Ex situ conservation of Bulgarian endemic plant Achillea thracica Velen. was achieved by successful in vitro cultivation of mono-nodal segments on MS-B5 medium supplemented with 1.0 mg/L BA for 20 days and subsequent transferring of regenerated plants on hormone free basal MS-B5 medium for root development and accumulation of leaf biomass. In vitro multiplicated plants were successfully acclimated in a growth chamber with 100% survival. GC–MS analysis of the essential oils resulted in the identification of 30, 10 and 28 compounds in in situ grown, in vitro cultivated and ex vitro adapted plants, respectively, constituting 77.7%, 99.9% and 84.1% of the total oils. The wider variety of compounds was found in the essential oils of in situ and ex vitro adapted plants where santolina alcohol, β-eudesmol, 1,8-cineole, germacrene D, α-cadinol and artemisia alcohol were the principal components comprising 68.7% and 69.3 of the oil, respectively. In vitro cultivated plants consist of mainly 1,8-cineole, germacrene D and artemisia alcohol representing 87% of the oil. Different growth conditions affect the composition of essential oils, suggesting their possible involvement in the process of adaptation and surviving in changing environmental conditions.     

Chemotypes of Achillea millefolium transferred from 14 different locations in Lithuania to the controlled environment

The composition of essential oils hydrodistilled from 19 samples of inflorescences and leaves of Achillea millefolium L. plants, which were transferred from 14 natural habitats in Lithuania to the field collection, is reported. Total content of oil was 0.15–0.55% in inflorescences and 0.06–0.19% (v/w) in leaves. In total 117 compounds were identified positively or tentatively. Data obtained clearly indicate the presence of a remarkable chemical polymorphism within the population of A. millefolium in Lithuania. The content of the major constituents in the oils from inflorescences varied in the following ranges: β-pinene, 0.33–62.29%; β-myrcene, 0.05–69.76%; α-phelandrene, 0.13–29.96%; 1,8-cineole, 2.30–21.57%; and chamazulene, 0.08–30.70%. According to the major components the essential oils' six chemotypes of A. millefolium were defined.     

Survival in different habitats: Extreme ultramafic and calcareous soils affect Stachys recta essential oils composition

Two populations of Stachys recta growing in Italy on ultramafic and calcareous soils have been studied for their essential oils. Although the yields were comparable, the composition of the essential oils differed significantly. Plants growing on ultramafic soil produced mainly non-terpene derivatives (55.7%), of which the most abundant ones were 1-octen-3-ol (38.2%) and (E)-3-hexen-1-ol (5.9%); the terpenes α-cadinol (6.1%) and δ-cadinene (5.6%) were also significantly represented. In contrast, the populations living on calcareous soil produced an essential oil dominated by terpenes (93.8%), with germacrene D (18.8%), β-caryophyllene (17.7%), 1,8-cineole (15.9%) and α-pinene (14.2%) among the main components.     

Analysis of leaf oils from a Eucalyptus species trial

The volatile leaf oils were analysed from adult leaves of five Eucalyptus species growing in a common environment. The trial consisted of two provenances of the species E. globulus and one provenance each of E. nitens and E. denticulata from the southern blue gum group and two provenances each of the species E. delegatensis and E. regnans from the ash group. Oil yields from adult leaves of E. nitens (0.7% dry wt.) and E. denticulata (0.8%) were markedly lower than those from the other three species (3.0–6.1%). Volatile leaf oils of E. delegatensis and E. regnans were rich in α- and β-phellandrene, cis- and trans-p-menth-2-en-1-ol, while E. regnans was also rich in α-, β- and γ-eudesmol. In contrast, volatile leaf oils of E. globulus were rich in 1,8-cineole and α-pinene and E. denticulata rich in γ-terpinene and p-cymene. Oil composition of E. nitens was intermediate between E. globulus and E. denticulata. Differences in oil yield and oil composition between species indicated a strong genetic basis for these variables.