Study of quantitative and qualitative variations in essential oils of Sicilian Rosmarinus officinalis L.

In this study the chemical characterisation of 10 Sicilian Rosmarinus officinalis L. biotypes essential oils is reported. The main goal of this work was to analyse the relationship between the essential oils yield and the geographical distribution of the species plants. The essential oils were analysed by GC-FID and GC-MS. Hierarchical cluster analysis and principal component analysis statistical methods were used to cluster biotypes according to the essential oils chemical composition. The essential oil yield ranged from 0.8 to 2.3 (v/w). In total 82 compounds have been identified, these represent 96.7–99.9% of the essential oil. The most represented compounds in the essential oils were 1.8-cineole, linalool, α-terpineol, verbenone, α-pinene, limonene, bornyl acetate and terpinolene. The results show that the essential oil yield of the 10 biotypes is affected by the environmental characteristics of the sampling sites while the chemical composition is linked to the genetic characteristics of different biotypes.     

Volatile constituents and antioxidant activity of flowers, stems and leaves of Nasturtium officinale R. Br

GC-MS analyses of the essential oils of leaves, stems and flower of Nasturtium officinale resulted in the identification of 9, 8 and 15 compounds, representing 97%, 100% and 94.7% of the oils, respectively. The main compounds of the oil of leaves were myristicin (57.6%), α-terpinolene (8.9%) and limonene (6.7%). Caryophyllene oxide (37.2%), p-cymene-8-ol (17.6%), α-terpinolene (15.2%) and limonene (11.8%) were the main components in stems, whereas limonene (43.6%), α-terpinolene (19.7%), p-cymene-8-ol (7.6%) and caryophyllene oxide (6.7%) were the major constituents in the oil of flowers. All the samples were subjected to a screening for their possible antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid assays. In the above tests, methanol extracts of leaves showed higher antioxidant activity than the oils and methanol extracts of stems and flowers.     

The essential oils of the aerial parts of two Hypericum taxa (Hypericum triquetrifolium and Hypericum aviculariifolium subsp. depilatum var. depilatum (Clusiaceae)) from Turkey

In this study, essential oil compositions of two Hypericum L. taxa (Hypericum triquetrifolium Turra. and Hypericum aviculariifolium Jaub. et Spach subsp. depilatum var. depilatum (Freyn et Bornm.) Robson) naturally grown in Turkey were determined using gas chromatography and gas chromatography-mass spectrometry systems. The essential oils were obtained by hydrodistillation from the aerial parts of plants. A total of 45 compounds were identified in the essential oils of H. triquetrifolium; 1-hexanal (18.8%), 3-methylnonane (12.5%) and α-pinene (12.3%). In this study, 41 components were identified in H. aviculariifolium subsp. depilatum var. depilatum oil; α-pinene (52.1%), germacrene D (8.5%) and β-pinene (3.6%) were the predominant constituents. The essential oil analysis showed that monoterpene concentrations were higher than that of the sesquiterpenes in both oils. The results were discussed in the meaning of the usefulness of these plants and their chemicals as natural products and potential usage in chemotaxonomy.     

Chemical composition and antioxidant activity of essential oil from berries of Schisandra chinensis (Turcz.) Baill

Essential oils of Schisandra chinensis seeds and berries without seeds were separately extracted. A total of 55 compounds were identified in the essential oil of berries without seeds (EOB), representing 85.75% of the total content. A total of 52 compounds were identified in the essential oil of seeds (EOS), representing 89.74% of the total content. For EOB, the top three content compounds were α-cis-bergamotene (10.79%), 4,11-selinadiene (5.28%) and α-cadinol (5.19%), while the top three content compounds of EOS were ylangene (10.16%), β-himachalene (9.46%) and di-epi-α-cedrene (8.92%). The antioxidant activity of the essential oil was tested using the DPPH radical-scavenging method. The antioxidant activity of EOB was higher than EOS. The IC(50) values of EOB and EOS were 8.4 and 15.8?mg/mL, respectively. This study concluded that EOB and EOS were not only different in extraction yield but also in chemical composition and antioxidant activity.     

Chemical investigation of the essential oil from berries and needles of common juniper (Juniperus communis L.) growing wild in Estonia

The essential oils obtained by simultaneous distillation and extraction (SDE) from the fresh and dried needles and dried berries of Juniperus communis L. of Estonian origin were subjected to GC-FID and GC-MS analyses. The yields of the oils ranged between 0.2% and 0.6% from juniper berries and between 0.5% and 1.0% from needles (dried weight). A total of 87 compounds were identified, representing over 95% of the oil. The major compounds in the needle oil were monoterpenes α-pinene (33.3-45.6%), sabinene (0.2-15.4%), limonene (2.8-4.6%) and sesquiterpenes (E)-β-caryophyllene (0.8-10.3%), α-humulene (0.8-6.2%) and germacrene D (3.0-7.8%). The juniper berry oil was rich in α-pinene (53.6-62.3%), β-myrcene (6.5-6.9%) and germacrene D (4.5-6.1%). The main oxygenated terpenoids found in the needle oil were germacrene D-4-ol (0.4-4.0%) and α-cadinol (to 2.7%). The oil from fresh needles contained high amounts of (E)-2-hexenal (3.7-11.7%).     

Essential oil composition and antiradical activity of the oil of Iraq plants

This study examined the antiradical activity and chemical composition of essential oils of some plants grown in Mosul, Iraq. The essential oils of myrtle and parsley seed contained α-pinene (36.08% and 22.89%, respectively) as main constituents. Trans-Anethole was the major compound found in fennel and aniseed oils (66.98% and 93.51%, respectively). The dominant constituent of celery seed oil was limonene (76.63%). Diallyl disulphide was identified as the major component in garlic oil (36.51%). Antiradical activity was higher in garlic oil (76.63%) and lower in myrtle oil (39.23%). The results may suggest that some essential oils from Iraq possess compounds with antiradical activity, and these oils can be used as natural antioxidants in food applications.     

Chemical composition and insecticidal activity against Sitophilus zeamais of the essential oils derived from Artemisia giraldii and Artemisia subdigitata

The aim of this research was to determine the chemical composition and insecticidal activity of the essential oils derived from flowering aerial parts of Artemisia giraldii Pamp. and A. subdigitata Mattf. (Family: Asteraceae) against the maize weevil (Sitophilus zeamais Motsch.). Essential oils of aerial parts of A. giraldii and A. subdigitata were obtained from hydrodistillation and investigated by GC and GC-MS. A total of 48 and 33 components of the essential oils of A. giraldii and A. subdigitata were identified, respectively. The principal compounds in A. giraldii essential oil were β-pinene (13.18%), iso-elemicin (10.08%), germacrene D (5.68%), 4-terpineol (5.43%) and (Z)-β-ocimene (5.06%). 1,8-Cineole (12.26%) and α-curcumene (10.77%) were the two main components of the essential oil of A. subdigitata, followed by β-pinene (7.38%), borneol (6.23%) and eugenol (5.87%). The essential oils of A. giraldii and A. subdigitata possessed fumigant toxicity against the maize weevils with LC50 values of 6.29 and 17.01 mg/L air, respectively. The two essential oils of A. giraldii and A. subdigitata also exhibited contact toxicity against S. zeamais adults with LD50 values of 40.51 and 76.34 μg/adult, respectively. The results indicated that the two essential oils show potential in terms of fumigant and contact toxicity against grain storage insects.     

Rapid analysis of Achillea tenuifolia Lam essential oils by polythiophene/hexagonally ordered silica nanocomposite coating as a solid-phase microextraction fibre

In this work, a highly porous fibre coated with polythiophene/hexagonally ordered silica nanocomposite (PT/SBA-15) was prepared and used for extraction of essential oils with microwave-assisted distillation headspace solid phase microextraction (MA-HS-SPME) method. The prepared nanomaterials were immobilised on a stainless steel wire for fabrication of the SPME fibre. Using MA-HS-SPME followed by GC-MS, 24 compounds were separated and identified in Achillea tenuifolia, which mainly included limonene (28.6%), α-cadinol (12.7%), borneol (6.7%), caryophyllene oxide (3.2%), bornyl acetate (4.3%), camphene (3.2%) and para-cymene (2.3%). The experimental results showed that the polythiophene/hexagonally ordered silica nanocomposite fibres were suitable for the semi-quantitative study of the composition of essential oils in plant materials and for monitoring the variations in the volatile components of the plants.     

Essential oil composition and antibacterial activity of Lindera nacusua (D. Don) Merr.

This study represents the first report on the chemical composition and biological activity of the essential oils from the leaves of Lindera nacusua (D. Don) Merr. Twenty-two compounds were identified and quantified, and the major components of the oil were Caryophyllene oxide (8.79%), Hexahydrofarnesyl acetone (6.83%), β-Selinene (5.02%), Neophytadiene (4.53%), Palmitic acid (4.42%), Phytol (4.36%), α-Copaene (3.89%), 4a,5,8,8a-β-Tetrahydro-2,4,5-trimethyl-1,4-naphthalindione (3.83%), α-Cadinol (3.17%), Bulnesol (2.65%) and 1,4-Dimethyl-7-(1-methylethyl) azulene (2.38%). The in vitro antibacterial activities of the essential oils were evaluated by the disc diffusion method. The inhibition zones against Staphylococcus aureus and Candida albicans were 23.7 and 23 mm. So the essential oil of L. nacusua showed potent antibacterial activity and potential high selectivity against S. aureus and C. albicans.     

Reporting effective extraction methodology and chemical characterization of bioactive components of under explored Platycladus orientalis (L.) Franco from semi-arid climate

The bioactive ingredients of many essential oils are complex and difficult to reproduce synthetically. In the present study, the influence of extraction method on relative extraction of bioactive compounds of essential oil of Platycladus orientalis (L.) Franco (Thuja orientalis L. is a synonym of it) leaves gathered from semi-arid climate was studied. A higher yield of essential oil was obtained by hydrodistillation (0.1%) as compared to steam distillation (0.07%) under newly optimized conditions. Initial analysis of these oils by TLC showed the presence of different polarity groups ranging from non-polar terpene hydrocarbons to polar terpenoid alcohols. GC-MS analysis revealed that major component of hydrodistilled essential oil of Platycladus orientalis (L.) Franco leaves was α-pinene (17.83%) and steam distilled essential oil contained α-cedrol (12.44%). The results obtained in the present study emphasize that suitable extraction technique should be used to obtain particular component of interest.     

Chemical variability in the essential oil of Cinnamomum tamala L. leaves from India

The chemical composition of the essential oils obtained from the fresh leaves of Cinnamomum tamala Nees et Eberm. was determined by GC and GC-MS. The yield of the oil on a dry weight basis ranged from 1.2% to 3.9% (w/w). Phenyl propanoids constitute the major portion (88.9-95.0%) of the oils. Fifty-four compounds were identified from the oils. Eugenol (91.4-41.8%) was the main compound, followed by eugenyl acetate (0.0-47.1%) and α-phellandrene (0.6-2.5%) in the analysed oils.     

Comparative essential oil composition of aerial parts of Tanacetum dumosum Boiss. from Southern Zagros,Iran.

The essential oils of leaves and flowers of Tanacetum dumosum Boiss., an endemic medicinal shrub, were extracted by using hydrodistillation method and analysed using GC and GC–MS. A total of 43 and 44 compounds were identified in the essential oils from the leaves and flowers of T. dumosum, respectively. The major chemical constituents of leaves oil were borneol (27.9%), bornyl acetate (18.4%), 1,8-cineol (17.5%), α-terpineol (5.3%), cis-chrysanthenyl acetate (3.3%), camphene (2.7%) and terpinene-4-ol (1.9%), while the main components of the flower oil were isobornyl-2-methyl butanoate (41.1%), trans-linalyl oxide acetate (11.9%), 1,8-cineole (7.7%), thymol (4.2%), linalool (3.9%), camphor (2.9%), isobornyl propanoate (2.9%), α-terpineol (2.1%) and caryophyllene oxide (2.0%). Major qualitative and quantitative variations for some main chemical compounds among different aerial parts of T. dumosum were identified. High contents of borneol, bornyl acetate, 1,8-cineol and linalool in the leaves and flowers of T. dumosum show its potential for use in the food and perfumery industry.     

Chemical composition and antimicrobial activity of the essential oils of Onychopetalum amazonicum R.E.Fr.

The essential oils from leaves, twigs and trunk bark of Onychopetalum amazonicum R.E. Fr. (Annonaceae), obtained by hydrodistillation, were analysed by GC and GC–MS, and also were evaluated for in vitro antimicrobial activity. Forty-one compounds, which correspond to 75.0–92.2% of the oil components, were identified. Major compounds were sesquiterpenes, including (E)-caryophyllene, caryophyllene oxide, spathulenol, α-gurjunene, allo-aromadendrene and α-epi-cadinol. The oils were evaluated for antimicrobial activities against four bacteria strains and five pathogenic fungi. The oil of the trunk bark exhibited good activity against Staphylococcus epidermidis ATCC 12228, Escherichia coli ATCC 10538 and Kocuria rhizophila ATCC 9341, with a minimal inhibitory concentration of 62.5 μg/mL. The essential oil composition and the antimicrobial evaluation are reported for the first time for the genus Onychopetalum.     

Essential oil from Artemisia herba-alba Asso grown wild in Algeria: Variability assessment and comparison with an updated literature survey

The chemical variability of the essential oils of Artemisia herba-alba Asso aerial parts, collected at Algeria was evaluated. A. herba-alba populations were collected in four regions, Benifouda; Bougaa; Boussaada and Boutaleb, at two different periods, July (flowering phase), and October and November (vegetative phase). The essential oils were isolated by hydrodistillation and analyzed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). The essential oils yield ranged between 0.2% and 0.9% (v/d.w.). Fifty components were identified in A. herba-alba oils, oxygen-containing monoterpenes being dominant in all cases (72–80%). Camphor (17–33%), α-thujone (7–28%) and chrysanthenone (4–19%) were the major oil components. Despite the similarity in main components, three types of oils could be defined, (a) α-thujone : camphor (23–28:17–28%), (b) camphor : chrysanthenone (33:12%) and (c) α-thujone : camphor : chrysanthenone (24:19:19%). The comparison between the present data and an updated survey of the existing literature reinforces the major variability of A. herba-alba essential oils and stresses the importance of obtaining a defined chemical type crop production avoiding the wild harvest.     

A study on the seasonal variation of the essential oil composition from Plectranthus hadiensis and its antibacterial activity

The chemical composition and seasonal variation of the essential oil from the aerial parts of Plectranthus hadiensis grown during the rainy and summer seasons in the Western Ghats of India was analysed by GC–MS technique. The analysis of rainy season oil led to the identification of 31 compounds, representing 96.4% of the essential oil and the winter season oil led to 25 compounds, representing 95.1% of the oil. Most of the compounds were sesquiterpenes and oxygenated monoterpenes. The major components of the rainy season oil were L-fenchone (30.42%), β-farnesene (11.87%), copaene(11.10%), 2,3-dimethyl hydroquinone (10.78%), α-caryophyllene(8.41%) and piperitone oxide (3.94%) and of the summer season oil are L-fenchone (31.55%), copaene(11.93%), β-farnesene (10.45%), 1,8-naphthalenedione, 8a-ethylperhydro (10.06%), α-caryophyllene(6.36%), piperitone oxide (5.79%) and limonene(4.63%). Antibacterial activity of the essential oil of P. hadiensis was tested using zone of inhibition and minimum inhibition concentration methods. Both the oils inhibited the organisms and showed the zone of inhibition in the range of 20–35 mm with MIC values between 32 and 64 mg/dL.     

Anti-quorum sensing activity of essential oils from Colombian plants

Essential oils from Colombian plants were characterised by GC-MS, and assayed for anti-quorum sensing activity in bacteria sensor strains. Two major chemotypes were found for Lippia alba, the limonene-carvone and the citral (geranial-neral). For other species, the main components included α-pinene (Ocotea sp.), β-pinene (Swinglea glutinosa), cineol (Elettaria cardamomun), α-zingiberene (Zingiber officinale) and pulegone (Minthostachys mollis). Several essential oils presented promising inhibitory properties for the short chain AHL quorum sensing (QS) system, in Escherichia coli containing the biosensor plasmid pJBA132, in particular Lippia alba. Moderate activity as anti-QS using the same plasmid, were also found for selected constituents of essential oils studied here, such as citral, carvone and α-pinene, although solely at the highest tested concentration (250?μg?mL(-1)). Only citral presented some activity for the long chain AHL QS system, in Pseudomonas putida containing the plasmid pRK-C12. In short, essential oils from Colombian flora have promising properties as QS modulators.     

Optimization of microwave-assisted hydro-distillation essential oil extracted from Rumex Crispus leaves using definitive screening design

Conversion of nonfood natural products to value-added products is an important work, which is going on worldwide. In addition, to obtain a product with better quality, a sufficient separation method is helpful to improve its utilization value by using effective, rapid and environmentally friendly techniques. Thus in this work, the microwave-assisted hydrodistillation (MAHD) process of essential oils from important natural plant Rumex Crispus leaves was investigated. The experimental design and extraction conditions were optimized using a definitive screening design. The yield of essential oils of 4.67 ± 0.02 % was investigated under the optimum conditions; 534.89 W of microwave power, 23.48 min of hydrodistillation time and 4.5 mL/g of the volume of water to plant mass ratio. Under these conditions, the essential oils were analyzed using gas chromatography-mass spectrometry (GC–MS). Results revealed that the essential oil extracted by MAHD possessed high quality as proved by its higher percentage of oxygenated compounds. In addition, α-santol (29.63 %) and β-santol (25.60 %) are the primary components of oxygenated compounds in essential oils. In conclusion, the MAHD was successfully employed to obtain mainly Oxygenated compounds-rich essential oil that may be used in several industrial applications. Subsequently, a definitive screening design may be regarded as an alternative and reliable method for the prediction of experimental parameters. It was concluded that the weeds plant (Rumex Crispus) contains a reliable quantity of oils that is extremely feasible to use and recommended as good feedstock for possible use in industrial applications.     

GC–MS Analysis of the Essential Oils of Piper nigrum L. and Piper longum L.

A simple, rapid and solvent-free method based on gas chromatography–mass spectrometry (GC–MS) following microwave distillation and headspace solid-phase microextraction (MD–HS-SPME) was developed for the analysis of the essential oils in two traditional Chinese medicines, Piper nigrum L. and Piper longum L. Thirty compounds were separated and identified from P. nigrum L. The main components were β-caryophyllene (23.49%), 3-carene (22.20%), d-limonene (18.68%), β-pinene (8.92%) and α-pinene (4.03 %). Forty-five compounds were separated from P. longum L. and identified. The main components were β-caryophyllene (33.44%), 3-carene (7.58%), eugenol (7.39%), d-limonene (6.70%), zingiberene (6.68%) and cubenol (3.64%). To demonstrate its advantages, MD–HS-SPME was compared to conventional HS-SPME. With conventional HS-SPME, only 28 and 33 compounds were detected in P. nigrum L. and P. longum L, respectively. Relative standard deviation (RSD) values of MD–HS-SPME for the essential oils in P. nigrum L. under optimal conditions were less than 10%. The results show that microwave distillation has a high extract efficiency and good precision and can be used to compare similarities and differences of essential oils.     

Composition of essential oils in subterranean organs of three species of Valeriana L

Essential oils from the subterranean organs of three species of Valeriana L. from Iran (Valeriana sisymbriifolia Vahl, Valeriana alliariifolia Adams and Valeriana officinalis L.) belonging to Valerianaceae family have been obtained by hydrodistillation and analysed by gas chromatography-mass spectrometry in order to discern the differences and similarities between the volatile chemical compositions of these species. More than 100 components were identified in essential oils of the studied plants (Supplementary Table S1--online only). The principal common constituents of the three species of Valeriana were spathulenol, limonene, γ-terpinene, vulgarone B and p-cymene. The main essential oil ingredients were α-selinene (7.83%) in V. sisymbriifolia, limonene (3.53%) in V. alliariifolia and spathulenol (13.33%), α-campholenal (11.48%), vulgarone B (8.38%) and valerenal (8.32%) in V. officinalis plants. Ageratochromene (precocene II), a chromene substance with antibacterial, antifungal, insecticidal and antijuvenile hormonal activities, was found at high levels (35.59% and 36.58%) in the essential oils of V. sisymbriifolia plants.     

GC/MS analysis and antimicrobial activity of the essential oil of fresh leaves of Eucalytus globulus, and leaves and stems of Smyrnium olusatrum from Constantine (Algeria)

The essential oils of fresh leaves of Eucalyptus globulus L. (Myrtaceae), and leaves and stems of Smyrnium olusatrum L. (Apiaceae), obtained by hydrodistillation in a Clevenger-type apparatus, were analyzed by GC/MS. Twenty compounds were characterized, representing 98.3% of the essential oil of E. globulus, with 1,8-cineole (48.6%), globulol (10.9%), trans-pinocarveol (10.7%), and alpha-terpineol (6.6%) as main components, while thirty-three compounds were characterized, representing 94.3% of the essential oil of S. olusatrum, with sabinene (27.1%), curzerene (13.7%), methyl-1-benzyl-2-oxocyclooctane carboxylate (12.3%), alpha-pinene (7.2%), cryptone (7.1%) and beta-pinene (5.7%) as the major components. The essential oils of E. globulus and S. olusatrum were tested against a wide range of fungal and bacterial strains. Both oils showed significant antimicrobial activity.