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Background: The current study examined the chemical profile and in vitro antibacterial activity of essential oils (EOs) extracted from Aframomum danielli (leaves and seeds), Aframomum chlamydentum (leaves), and Aframomum melegueta (leaves) against foodborne pathogenic bacteria. Methods: The hydro-distillation technique using a Clevenger-type apparatus was used to extract EOs, whereas the Gas Chromatography-Mass Spectrometry (GC-MS) and GC coupled to Flame Ionization Detector (GC-FID) allowed the chemical characterization of oil constituents. The broth micro-dilution method was applied for the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Besides, some modes of action were studied on the cell membrane integrity and biofilm formation of Salmonella typhi. Results: The major compounds identified from EOs of A. danielli seeds were eucalyptol (48.707%), limonene (11.368%), beta pinene (10.342-10.335%), and alpha terpineol (8.785-9.049%), whereas EOs from A. danielli leaves were dominated by sabinene (42.87%), beta pinene, (11.22%), caryophyllene (7.84%), terpinen-4-ol (5.68%), linalool (3.48%) and gamma terpinene (2.02%). Major volatile markers from EOs of A. chlamydentum leaves comprised beta pinene (49.72%), caryophyllene (10.62%), alpha pinene (6.21%) and linalool (2.96%), while those of EOs from A. melegueta included beta pinene (37.15%), caryophyllene (17.64%), caryophyllene oxide (8.72%) and alpha pinene (8.26%). This study is the first to report on the chemical constituents of EOs from A. chlamydentum. Test oils displayed significant antibacterial activity with the MIC ranging from 0.0625 to 0.5% (v/v). EOs from A. melegueta (leaves) appeared to be the most active, acting against all tested bacteria. All EOs identified displayed bactericidal effects against Citrobacter freundii, a bacterium known to cause a broad range of infections associated with a higher rate of in-hospital mortality. The EOs from A. melegueta may act through perturbation of cell membrane integrity and permeability as well as the inhibition of bacterial biofilm formation. Conclusion: Our findings suggest the possible application of essential oils in agricultural food products for the control of bacterial diseases.

Oral squamous cell carcinoma (OSCC) is the most common type of head and neck malignancy. Research on essential oils (EOs) has shown important cytotoxic and anti-tumor properties, among others. Piperaceae species are rich in EOs and here we highlight Piper rivinoides Kunth. We investigated the crude EOs from P. rivinoides, their pure major constituents and an enriched fraction with the main EO compounds (EF) as cytotoxic and selective OSCC agents. EOs presented as main compounds (-)-α-pinene, (-)-β-pinene and limonene. EOs showed an IC50 lower than all isolated compounds, except for (-)-β-pinene in OSCC cells. The (-)-β-pinene induced cell death with apoptotic characteristics. Commercial standards showed greater selectivity than EOs, and (-)-β-pinene was the most selective among them. EF showed higher selectivity compared to crude EOs and carboplatin, turning it into a good candidate as an anticancer fraction. These results are important for the possible development of new treatments for OSCC.

Hyssop [Hyssopus officinalis L. subsp. angustifolius (Bieb.)] belonging to the family Lamiaceae, is an important medicinal and aromatic plant in Iranian folk medicine. The herb grows wildly in the alpine regions from northwestern to southwestern of Iran. A GC-FID and GC/MS analysis of essential oils isolated from the inflorescences of two Iranian landraces of this herb including white and purple flowers identified 25, and 22 constituents, respectively (accounting for 98 % of the total oils). The essential oil yields were 0.40 and 0.45 ml/100 g based on the dry weight of plant material for white and purple flowers, respectively. The major constituents of the essential oil from purple landrace were cis-pinocamphone (55.14 %), β-pinene (17.06 %), and trans-pinocamphone (3.50 %). However, camphor (31.85 %), cis-pinocamphone (30.11%), β-pinene (12.26 %), and trans-pinocamphone (6.09 %) were the main compositions of the essential oil from white landrace of hyssop. Antioxidant activity of the essential oils was determined by DPPH assay and the essential oils of both landraces showed moderate antioxidant activity. This potential applicability can be used as antioxidant agents for food and pharmaceutical industries. The essential oils of the two studied hyssop landraces sourced in the alpine region of southwestern Iran were rich in oxygenated monoterpenes. Generally, the herb proved to be relatively good sources of chemical products and medicinal compounds such as camphor, pinocamphone and β-pinene that are widely used in food and drug industries.

Tetranychus urticae is a major agricultural pest with worldwide distribution that has caused considerable damage to vegetable crops in north‐eastern Brazil. The aim of the present study was to investigate the chemical and lethal/sublethal effects of essential oils from the peels of the lime (Citrus aurantiifolia), lemon (C. limon), mandarin orange (C. reticulata) and (C. reticulata × C. sinensis) as well as selected constituents (linalool, α‐terpineol, α‐pinene, β‐pinene, terpinolene and limonene) against T. urticae. The greatest yield was achieved with the mandarin and tangerine peel oils. The chemical analysis (gas chromatography‐mass spectrometry) of the essential oils from the Citrus fruit peels enabled the identification of 127 compounds, revealing a predominance of monoterpenes. Limonene was the major constituent, and α‐pinene, β‐pinene, linalool and α‐terpineol were found in substantial quantities. Regarding the susceptibility of T. urticae, the Citrus oils and selected constituents were more effective by fumigation than residual contact. The C. reticulata oil was the most toxic by fumigation, and the C. limon oil was the most toxic by residual contact. The constituent α‐terpineol exhibited the highest toxicity with both methods. At a sublethal concentration, the oils and selected constituents had significant effects on the fecundity, feeding preference and oviposition of the mite. Citrus oils and their constituents are potentially useful for the future integrated management of T. urticae due to their lethal and sublethal properties. However, further studies are needed to evaluate the action of these essential oils against non‐target organisms and determine the cost–benefit ratio for the formulation of an acaricide harvested from agro‐industrial waste from citric fruit processing activities for use in the integrated control of T. urticae.

Essential oils have received considerable attention because they are important sources for the discovery of new antimicrobial agents. The use of essential oils for food preservation has emerged as a promising approach to reduce the microbial growth of food. Taxodium plants are fast-growing and long-lived trees that are widely cultivated in many countries for landscape and ecological purposes. The trees are famous for their extremely rot and termite resistant wood. The essential oil of Taxodium was used in folk medicine to treat infections, gastrointestinal and respiratory ailments. This study aimed to determine the composition of the essential oil obtained from the leaves of T. distichum var distichum (L.) Rich. GC/MS analysis revealed the presence of 37 compounds for the first time, representing 99.5% of the oil content. α-Pinene was the major component, accounting for 83.1% of the oil content, followed by cis-thujopsene (1.9%), camphene (1.8%), β-pinene (1.6%), β-myrcene (1.4%), and D-limonene (1.1%). Monoterpene hydrocarbons represented the predominant components (90.4%), followed by sesquiterpene hydrocarbons (4%), oxygenated monoterpenes (2.9%), oxygenated sesquiterpenes (1.5%), and oxygenated diterpenes (0.5%). The antibacterial and antifungal activity of the essential oil was tested using agar diffusion method. The inhibition zones and MIC were determined. It was clear that T. distichum essential oil showed growth inhibition of most tested strains of Gram-positive and Gram-negative bacteria as well as fungi. Most notably, Bacillus subtilis andmethicillin‐resistant Staphylococcus aureus (MRSA) were more susceptible to the oil with MIC values of 9.8 and 39 μg/mL, respectively. The oil produced the largest inhibition zones for these two Gram-positive microorganisms (32.9 and 21.9 mm, respectively). T. distichum oil exhibited a potent activity against Klebsiella pneumonia (MIC of 4.9 μg/mL, zone of inhibition of 33.9 mm), which is very comparable to gentamycin (MIC of 1 μg/mL, zone of inhibition of 21.2 mm). Salmonella typhimurium was also susceptible to the oil (MIC of 78.1 μg/mL, inhibition zone of 17 mm). T. distichum essential oil showed a very potent antifungal effect against Asperigullus fumigatus (MIC of 9.8 μg/mL, zone of inhibition of 25.9 mm) when compared with ketoconazole (MIC of 50 μg/mL, zone of inhibition of 21.0 mm). T. distichum essential oil exhibited a potent anti-mycobacterial effect in Alamar Blue assay (63% inhibition, MIC of 1.95 μg/mL) when compared with isoniazid (100% inhibition, MIC of 0.12 μg/mL). It can be concluded that T. distichum essential oil is a promising antimicrobial agent against different pathogens. The oil components could enhance the activity of other antimicrobial agents through synergism. This could be of great interest in food, cosmetic and pharmaceutical applications.

Monoterpenes are plant secondary metabolites, widely used in industrial processes as precursors of important aroma compounds, such as vanillin and (−)-menthol. However, the physicochemical properties of monoterpenes make difficult their conventional conversion into value-added aromas. Biocatalysis, either by using whole cells or enzymes, may overcome such drawbacks in terms of purity of the final product, ecological and economic constraints of the current catalysis processes or extraction from plant material. In particular, the ability of oxidative enzymes (e.g., oxygenases) to modify the monoterpene backbone, with high regio- and stereo-selectivity, is attractive for the production of “natural” aromas for the flavor and fragrances industries. We review the research efforts carried out in the molecular analysis of bacterial monoterpene catabolic pathways and biochemical characterization of the respective key oxidative enzymes, with particular focus on the most relevant precursors, β-pinene, limonene and β-myrcene. The presented overview of the current state of art demonstrates that the specialized enzymatic repertoires of monoterpene-catabolizing bacteria are expanding the toolbox towards the tailored and sustainable biotechnological production of values-added aroma compounds (e.g., isonovalal, α-terpineol, and carvone isomers) whose implementation must be supported by the current advances in systems biology and metabolic engineering approaches., This work was supported by the project VALEU (PTDC/EAM-AMB/30488/2017); by the strategic program UID/BIA/04050/2019 through the Fundação para a Ciência e a Tecnologia (FCT) I.P.; and by the European Regional Development Fund (ERDF) through the COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI). The work was also supported by a Ph.D grant (grant number PD/BD/146184/2019) to F.S.

This article presents research related to the transformation of geraniol (GA), leading to the formation of products with very valuable properties. In the planned method, heterogeneous catalysts of natural origin in the form of alum and diatomite were used as catalysts. Initially, the process which we investigated was the process of isomerization of GA, but it turned out during the studies that GA is also transformed in other reactions. Before catalytic tests, these two minerals were subjected to detailed instrumental analyses using the following methods: XRD, SEM/EDX, XRF and FTIR, which allowed to obtain their full morphological characteristics. During the catalytic tests, the influence of such relevant parameters on the GA transformations was determined: temperature from 80 to 150 °C, catalyst content from 5 to 15% by weight and the reaction time from 15 min to 24 h. The tests presented in the article were carried out under atmospheric pressure (in air) as well as without the use of a solvent. The optimal conditions for the transformations of GA were determined on the basis of its conversion and selectivities of transformation to the main products in the form of: beta-pinene (BP), 6,11-dimethyl-2,6,10-dodecatriene-1-ol (DC) and thumbergol (TH). The above products were formed with the highest selectivity, respectively: 100 mol%, 50 mol% and 52 mol%. The results of the syntheses showed that for GA the best transformation results were obtained at the temperature of 80 °C (for both tested catalysts), with the catalyst content of 1 wt % (for both tested catalysts) and for the reaction time of 1 h (for diatomite)) and 3 h (for alum).

The essential oils (EOs) were isolated by hydrodistillation from wild and cultivated Pistacia lentiscus L. var. chia&mdash, mastic gum tree (Anacardiaceae) from two natural habitats, namely from Cesme&ndash, Uzunkoy (1) and Mordogan (2), and one cultivated source, Cesme&ndash, Germiyan (3), in Izmir, Turkey. This comparative study evaluated the chemical composition and biological activity of mastic gum essential oils (MGEOs). For this purpose, MGEOs 1&ndash, 3 were analyzed by gas chromatography&ndash, flame ionization detection (GC-FID), gas chromatography&ndash, mass spectrometry (GC-MS), and chiral GC for &alpha, pinene. Laboratory assays were conducted to assess for potential in vitro cytotoxicity (multiple in vitro cancer cell lines), antimicrobial properties (five bacterial species and yeast), anti-inflammatory activity (inhibition of inducible nitric oxide synthase, iNOS), and the attraction of Ceratitis capitata (Mediterranean fruit fly, medfly), respectively. Chemical analysis indicated that MGEOs 1 and 2 were rich in &alpha, pinene (56.2% and 51.9%), myrcene (20.1% and 18.6%), and &beta, pinene (2.7% and 3.1%), respectively, whereas MGEO-3 was characterized by a high level of &alpha, pinene (70.8%), followed by &beta, pinene (5.7%) and myrcene (2.5%). Chiral GC analyses showed that concentration ratios between (&minus, )/(+)-&alpha, pinene and (&minus, )-&alpha, pinene/myrcene allowed for differentiation between wild and cultivated MGEO sources. In biological assays, MGEOs 1&ndash, 3 did not exhibit significant antimicrobial effects against the pathogens evaluated and were not strong attractants of male medflies, however, all three MGEOs displayed a dose-dependent inhibition of iNOS, and MGEOs 1 and 2 exhibited selective in vitro cytotoxicity against human cancer cells. These results suggest that wild-type mastic gum oils from Cesme and Mordogan (MGEOs 1 and 2) are potential sources of beneficial products and warrant further investigation.

In this research, we used Pistacia atlantica gum during cooling phase of oil-heat treatment of poplar wood (Populus deltoids) to improve its resistance to the white-rot fungus Trametes versicolor and growth of the mold fungus Penicillium expansum. Thermal modification was carried out using rapeseed oil at 180 °C, 200 °C and 220 °C for 2 hours and 4 hours. The modified wood specimens were then directly cooled in the oil containing 0 %, 5 % and 10 % (w/w) of the gum at 25 °C for 30 minutes. The chemical constituents of the essential oil extracted with a Clevenger type apparatus were determined by chromatography-mass spectrometry (GC-MS). The amounts of α-pinene, β-pinene and α-terpinolene of the essential oil were 60,2 %, 8,7 % and 3,9 %, respectively. The mold resistance was greatly improved, while the improvement against the decay fungus was only observed for the specimens modified at 180 °C. Our results confirmed that the enhanced fungal resistance was not only due to the presence of monoterpenes in the essential oil, but also to a further reduction in the hygroscopicity of the treated wood.

The aim of this research was to determine for the first the chemical constituents of essential oils derived from the leaves, pseudostems and rhizomes of Alpinia strobiliformis T. L. Wu & S....

Cupressus atlantica Gaussen is an endemic and threatened forest tree mainly located at the western High Atlas Mountains of Morocco. This study is a pleading for protection and restoration of this particular Mediterranean cypress species, through the characterization of chemical variability of its essential oils (EOs) and their recovery in different fields, especially as protective treatment against wood decaying fungi. Composite samples of leaves, twigs, and cones were collected within five populations. Sapwood and heartwood sawdust oils were also analyzed. EOs were extracted by hydrodistillation and analyzed by GC-MS. C. atlantica oils are characterized by high chemical variability between types of biomass and populations. Thus, leaves and twigs oils are dominated by hydrocarbon monoterpenes; those of wood by oxygenated monoterpenes and oxygenated sesqueterpenes, and those of cones by hydrocarbon monoterpenes and sesquiterpenes. Three chemical profiles have been identified in leaves oils within s...

This study investigated the reduction of terpene emissions from Oriented Strand Boards (OSB) by pre-treatment of pine wood strands with a mixed culture of Pseudomonas bacteria and the ascomycete Penicillium nigricans. While Pseudomonas alone efficiently degraded α-pinene and β-pinene, the combined action of both microorganisms was required for the simultaneous degradation of all three major terpenes in pine wood including Δ3-carene. Δ3-carene emissions from laboratory OSB were 60% and 35% lower than that of controls after 4 and 2 days of microbial pre-treatment, respectively. At the same time, α-pinene emissions were reduced by 85% and 45%, while β-pinene emissions were completely absent. Δ3-carene degradation was no longer observed at a short-term treatment of only 1 day. However, laccase in the presence of a redox mediator may overcome this limitation by oxidation of Δ3-carene to non-volatile carenones. The results revealed the potential of biotechnology for reducing potentially harmful terpene emissions from wood products.

Diaphania hyalinata is an important pest in organic melon crops and has caused considerable harm to growers in northeastern Brazil. The aim of the present study was to determine the chemical composition of essential oils from Eugenia uniflora (pitanga) and Cinnamomum zeylanicum (cinnamon) as well as evaluate the repellant action, oviposition deterrence and effect on body mass caused by the oils and the constituents linalool and β-pinene in D. hyalinata. The essential oils from pitanga and cinnamon had a predominance of sesquiterpenes and phenylpropanoids, respectively. The pitanga oil was more effective as a larval repellent than the cinnamon oil and the constituents tested exhibited low repellent activity. In the evaluation of oviposition deterrence, the response of D. hyalinata exposed to the cinnamon oil did not vary with the distance between the treated and untreated leaf disks, but varied significantly when exposed to the pitanga oil. Linalool exhibited greater long-distance oviposition deterrence in comparison with β-pinene. In the experiments on body mass gain, second-instar larvae were more susceptible to the cinnamon oil than the pitanga oil and constituents tested. The findings suggest that these oils, especially the pitanga oil, could be an alternative for the control of D. hyalinata in the larval and adult phases. Further studies are needed to evaluate the effect on natural enemies and pollinating insects as well as the cost–benefit of the formulation of an insecticide for use on organic crops in northeastern Brazil.

Aim of study: The objectives in this study were to determine the chemical composition and antimicrobial activity of the essential oils from nutmeg (Myristica fragrans) and cardamom (Elettaria cardamomum).Material and Methods: The essential oil was obtained from nutmeg and cardamom seeds through hydrodistillation method. The chemical composition of nutmeg and cardamom essential oil was analyzed by GC-MS. The antimicrobial activity of essential oil was investigated against Bacillus subtilis DSMZ 1971, Candida albicans DSMZ 1386, Enterococcus faecalis ATCC 29212, Enterobacter aerogenes ATCC 13048, Enterococcus durans, Enterococcus faecium, Escherichia coli ATCC 25922, Klebsiella pneumoniae, Listeria monocytogenes, Listeria innocua, Pseudomonas aeruginosa DSMZ 50071, Pseudomonas fluorescence P1, Salmonella enteritidis ATCC 13076, Salmonella infantis, Salmonella kentucky, Salmonella typhimurium SL 1344, Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis DSMZ 20044 with minimum inhibitory concentration (MIC) method.Main results: GC-MS analyzes shows that γ-terpinene (19.16%), (-)-terpinen-4-ol (14.08%), α-pinene (6.75%), myristicin (6.18%), β-pinene (4.85%), sylvestrene (4.72%), elemicin (4.68%) and safrole (4.17%) identified in nutmeg essential oil. Also, α-terpinyl acetate (34.55%), eucalyptol (24.91%), (-)-terpinen-4-ol (10.63%), linalool (7.69%) and neryl butyrate (6.58%) compounds identified in cardamom essential oil as major compounds. Nutmeg and cardamom essential oil showed an antimicrobial activity against almost all test microorganisms.Research highlights: This study suggests that nutmeg and cardamom essential oil may be useful in the medicinal application and food industry as a preservative., Çalışmanın amacı: Bu çalışmanın amacı, muskat (Myristica fragrans) ve kakule (Elettaria cardamomum) ‘den elde edilen uçucu yağlarının kimyasal içeriğinin ve antimikrobiyal aktivite özelliklerinin tespit edilmesidir.Materyal ve Yöntem: Muskat ve kakule tohumlarından uçucu yağ eldesi hidro distilasyon yöntemi ile yapılmıştır. Söz konusu bu uçucu yağların kimyasal içeriği GC-MS cihazı ile analiz edilmiştir. Anti mikrobiyal aktivite deneyi Bacillus subtilis DSMZ 1971, Candida albicans, Enterococcus faecalis ATCC 29212, Enterobacter aerogenes ATCC 13048, Enterococcus durans, Enterococcus faecium, Escherichia coli ATCC 25922, Klebsiella pneumoniae, Listeria monocytogenes, Listeria innocua, Pseudomonas aeruginosa DSMZ 50071, Pseudomonas fluorescence P1, Salmonella enteritidis ATCC 13076, Salmonella infantis, Salmonella kentucky, Salmonella typhimurium SL 1344, Staphylococcus aureus ATCC 25923 ve Staphylococcus epidermidis DSMZ 20044 mikroorganizmalarına karşı minimum inhibisyon konsantrasyonu (MIC) yöntemi ile belirlenmiştir.Sonuçlar: GC-MS analizi sonucunda muskat uçucu yağında γ-terpinene (19.16%), (-)-terpinen-4-ol (14.08%), α-pinene (6.75%), myristicin (6.18%), β-pinene (4.85%), sylvestrene (4.72%), elemicin (4.68%) and safrole (4.17%) ana bileşenler olarak tespit edilmiştir. Ayrıca, α-terpinyl acetate (34.55%), eucalyptol (24.91%), (-)-terpinen-4-ol (10.63%), linalool (7.69%) ve neryl butyrate (6.58%) bileşikleri de kakule uçucu yağının ana bileşenleri olarak tespit edilmiştir. Muskat ve kakule uçucu yağlarının deney mikroorganizmalar karşı antimikrobiyal aktiviteleri tespit edilmiştir.Araştırma vurguları: Uçucu yağın tıp ve gıda endüstrisinde koruyucu olarak kullanılması önerilmiştir.

The steam volatile constituents from the aerial parts and roots of Selinum vaginatum C. B. Clarke (Apiaceae) growing wild in the central Himalayan region of Uttarakhand, India were isolated by steam distillation and analyzed by capillary gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of thirty-one and forty-six constituents, representing 97.7 % and 96.7 % of the total oil composition were identified from the aerial parts and roots of S. vaginatum, respectively. The aerial parts oil consisted mainly of monoterpene hydrocarbons (48.7 %), with 2E,6E-farnesol (36.0 %), γ-terpinene (24.3 %) and β-pinene (16.3 %) as a major constituents while the roots oil mainly contains oxygenated sesquiterpenes (72.8 %), with maximum content of 2E,6Z-farnesol (60.0 %) and elemol (5.0 %). The oil samples showed significant antibacterial activity against Gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis and Gram-negative Klebsiella pneumoniae. Minimum i...

Zingiber officinale Roscoe leaves oil was hydrodistilled and analyzed by gas chromatography/mass spectrometry for the first time from the Egyptian chemotype. Ninety compounds (96.63% of total peak area) were identified. Methyl cinnamate (29.21%) represented the most abundant oxygenated compound. Monoterpene hydrocarbons (23.83%) were rich in β-pinene (8.59%) and terpinolene (7.46%). δ-Cadinene (7.05%) represented the majority of sesquiterpene hydrocarbons (20.86%). A nanoemulsion (diameter of 151.4 nm) was formulated by low-energy method using Tween-80 as surfactant, with polydispersity index of 0.27, zeta potential of -13.75 mV and pH value of 4. Transmission electron microscopy (TEM) confirmed the nanometric-sized particles. The formulation was stable by keeping in the refrigerator for one month. The nanoemulsion antimicrobial activity was tested against Streptococcus mutans (compared to clindamycin) with MIC value of 62.5 µL/mL, confirmed by TEM showing bacterial scattering with impaired biofilm formation, and by in-silico molecular docking of methyl cinnamate to the C-terminal region of S. mutans surface protein antigen. To our knowledge, the formulation and its anticariogenic activity validation were carried out for the first time. Thus, ginger leaves oil is rich in valuable phytoconstituents; its nanoemulsion showed efficacy on S. mutans, yet further studies are required for testing its applicability as a gargle.

Gas chromatographic analysis of Citrus tachibana (Makino) Tanaka peel essential oil showed that the volatile composition contained 111 components including monoterpenes, sesquiterpenes and oxygenat...

Heracleum candicans Wall. (Apiaceae) is one of the important endangered aromatic species within the genus Heracleum. Owing to multiple uses, high market demand and endangered status of species, a w...

Chemical constituents of the essential oil isolated from Salvia sahendica at different growth stages (vegetative, flowering and seeding (S-S) were identified. Among 50 identified oil constituents, ...

WOS: 000435102100003, The composition of the essential oil produced from aerial parts of Salvia montbretii Benth.(Lamiaceae), was analyzed by GC and GC-MS. Forty-six compounds constituting about 97.7% of the essential oil were characterized. The main compounds were characterized as beta-caryophyllene (32.8%), beta-pinene (9.8%), alpha-humulene (8.2%), 12-hydroxy-beta-caryophyllene acetate (6.6%), germacrene D (4.9%) and alpha-pinene (4.5%).

Junipers (Juniperus spp.) are some of the most widespread species in the world with a wide ecological adaptation. Juniper galbuli (cones or berries) and their extracts have extensive applications in pharmaceuticals, perfumery, aromatherapy, alcoholic beverages, and cooking. The objective of this study was to evaluate EO composition, antimicrobial and antioxidant activity of EO fractions captured at different timeframes during the hydrodistillation of Juniperus communis and J. excelsa galbuli. The EO fractions were captured at eight sequential timeframes after the beginning of the hydrodistillation: (0–3, 3–5, 5–10, 10–20, 20–40, 40–80, 80–160, and 160–240 min). The results showed that essential oil fractions from 80 to 160 and 160 to 240 min had 2–5 times greater antioxidant capacity than fractions captured at the beginning of the distillation or from the whole oil. The strongest antimicrobial activity of J. communis EO against Salmonella enterica subsp. enterica was observed in the EO obtained at the 0–3 min distillation timeframe (DT, in minutes). The EO of J. communis obtained at the 0 to 3, 3 to 5, and 80 to 160 min DTs showed greater antimicrobial activity against Klebsiella pneumonia, compared with the EO obtained from the 160 to 240 DT. The strongest activity of J. communis EO against Staphylococcus aureus subsp. aureus and Candida glabrata was observed with EO from the 160 to 240 DT. J. excelsa EO from the 0 to 3 and 5 to 10 min DTs had greater activity against S. enterica and K. pneumonia compared with the EO from the 160 to 240 DT. Conversely, the J. excelsa EO from the 160 to 240 min DT had greater activity against Clostridium perfringens and Candida glabrata. This research revealed that EO with different profiles could be obtained from the same batch of galbuli, suggesting the possibility of generating natural unadulterated oils with specific targeted profiles. Essential oils with a high content of α-pinene, β-pinene, β-myrcene, sabinene, or limonene was obtained from J. communis galbuli hydrodistilled for 3 min. Essential oil with a high content of α-pinene, β-pinene, β-myrcene, or γ-terpinene was obtained from J. excelsa galbuli when hydrodistilled for 3 min. The galbuli of J. communis and J. excelsa can yield essential oil fractions with novel chemical composition and bioactivity.

Secondary organic aerosol (SOA) plays a central role in air pollution and climate. However, the description of the sources and mechanisms leading to SOA is elusive despite decades of research. While stable isotope analysis is increasingly used to constrain sources of ambient aerosol, in many cases it is difficult to apply because neither the isotopic composition of aerosol precursors nor the fractionation of aerosol forming processes is well characterised. In this paper, SOA formation from ozonolysis of alpha-pinene an important precursor and perhaps the best-known model system used in laboratory studies-was investigated using position-dependent and average determinations of C-13 in alpha-pinene and advanced analysis of reaction products using thermal-desorption proton-transfer-reaction mass spectrometry (PTR-MS). The total carbon (TC) isotopic composition delta C-13 of the initial alpha-pinene was measured, and the delta C-13 of the specific carbon atom sites was determined using position specific isotope analysis (PSIA). The PSIA analysis showed variations at individual positions from -6.9 to +10.5 % relative to the bulk composition. SOA was formed from alpha-pinene and ozone in a constant-flow chamber under dark, dry, and low-NOx, conditions, with OH scavengers and in the absence of seed particles. The excess of ozone and long residence time in the flow chamber ensured that virtually all alpha-pinene had reacted. Product SOA was collected on two sequential quartz filters. The filters were analysed offline by heating them stepwise from 100 to 400 degrees C to desorb organic compounds that were (i) detected using PTR-MS for chemical analysis and to determine the o : C ratio, and (ii) converted to CO2 for C-13 analysis. More than 400 ions in the mass range 39-800 Da were detected from the desorbed material and quantified using a PTR-MS. The largest amount desorbed at 150 degrees C. The 0 : C ratio of material from the front filter increased from 0.18 to 0.25 as the desorption temperature was raised from 100 to 250 degrees C. At temperatures above 250 degrees C, the o : C ratio of thermally desorbed material, presumably from oligomeric precursors, was constant. The observation of a number of components that occurred across the full range of desorption temperatures suggests that they are generated by thermal decomposition of oligomers. The isotopic composition of SOA was more or less independent of desorption temperature above 100 degrees C. TC analysis showed that SOA was enriched in C-13 by 0.6-1.2%c relative to the initial cy-pinene. According to mass balance, gas phase products will be depleted relative to the initia alpha-pinene. Accordingly, organic material on the back filters, which contain adsorbed gas-phase compounds, is depleted in C-13 in TC by 0.7 % relative to the initial alpha-pinene, and by 1.3 % compared to SOA collected on the front filter. The observed difference in C-13 between the gas and particle phases may arise from isotope-dependent changes in the branching ratios in the alpha-pinene + O-3 reaction. Alternatively, some gas phase products involve carbon atoms from highly enriched and depleted sites, as shown in the PSIA analysis, giving a non-kinetic origin to the observed fractionations. In either case, the present study suggests that the site-specific distribution of C-13 in the source material itself governs the abundance of C-13 in SOA.

In the present work, volatile constituents from the dried stems, leaves and fruits of Artemisia tschernieviana obtained by hydrodistillation (HD), solvent-free microwave extraction (SFME) and headspace solid-phase microextraction (HS-SPME) techniques, were subsequently analyzed by means of GC and GC-MS instruments. It was concluded that approximately in all oils and volatiles, chemical compositions were mainly consisted of monoterpene hydrocarbons. However, in the stem oil and fruit volatiles isolated by SFME and HS-SPME methods, oxygenated monoterpenes and oxygenated sesquiterpenes were the most abundant constituting fractions. Additionally, the common major compounds in all essences and volatiles were recognized being β-pinene, cubenol, limonene, bornyl acetate and γ-terpinene. Moreover, a straightforward model has been developed to model the retention indices (RIs) of diverse natural compounds present in the obtained essential oils and volatile fractions basing on a quantitative structure-reten...

Black pepper (Piper nigrum) is historically one of the most important spices and herbal medicines, and is now cultivated in tropical regions worldwide. The essential oil of black pepper fruits has shown a myriad of biological activities and is a commercially important commodity. In this work, five black pepper essential oils from eastern coastal region of Madagascar and six black pepper essential oils from the Amazon region of Brazil were obtained by hydrodistillation and analyzed by gas chromatography-mass spectrometry. The major components of the essential oils were &alpha, pinene, sabinene, &beta, pinene, &delta, 3-carene, limonene, and &beta, caryophyllene. A comparison of the Madagascar and Brazilian essential oils with black pepper essential oils from various geographical regions reported in the literature was carried out. A hierarchical cluster analysis using the data obtained in this study and those reported in the literature revealed four clearly defined clusters based on the relative concentrations of the major components.

The chemical composition and biological activity of essential oils isolated from the leaves of Siparuna aspera, Siparuna macrotepala, Piper leticianum, Piper augustum and the rhizome of Hedychium coronarium were evaluated. These species are used medicinally in different ways by the Amazonian communities that live near the Kutuk&uacute, mountain range. Chemical studies revealed that the main components for the two Siparuna species were germacrene D, bicyclogermacrene, &alpha, pinene, &delta, cadinene, &delta, elemene, &alpha, copaene and &beta, caryophyllene, for the two Piper species &beta, caryophyllene, germacrene D, &alpha, (E,E)-farnesene, &beta, elemene, bicyclogermacrene, &delta, cadinene and for H. coronarium 1,8-cineole, &beta, pinene, &alpha, pinene and &alpha, terpineol. The antioxidant activity of all essential oils was evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2&prime, azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), photochemiluminescence (PCL) quantitative assays, and DPPH and ABTS bioautographic profiles, with different results for each of them. Antimicrobial activity studies were carried out on three yeasts, six Gram positive and four Gram negative bacteria, by means of the disc diffusion method. The essential oil of H. coronarium showed the most relevant results on L. grayi, K. oxytoca and S. mutans, P. augustum and P. leticianum on S. mutans. An antibacterial bioautographic test for H. coronarium was also carried out and highlighted the potential activity of terpinen-4-ol and 1,8-cineole.

The aim of this study was to determine how the addition of gold and silver nanoparticles to culture media affects the composition of essential oils extracted from Lavandula angustifolia propagated on MS media with the addition of 10 and 50 mg&bull, dm&minus, 3 of gold (24.2 &plusmn, 2.4 nm) and silver (27.5 &plusmn, 4.8 nm) nanocolloids. The oil extracted from the lavender tissues propagated on the medium with 10 mg&bull, 3 AgNPs (silver nanoparticles) differed the most with respect to the control, oil-10 compounds were not found at all, and 13 others were detected which were not present in the control oil. The addition of AuNPs (gold nanoparticles) and AgNPs to the media resulted in a decrease of lower molecular weight compounds (e.g., &alpha, and &beta, pinene, camphene, &delta, 3-carene, p-cymene, 1,8-cineole, trans-pinocarveol, camphoriborneol), which were replaced by those of a higher molecular weight (&tau, and &alpha, cadinol 9-cedranone, cadalene, &alpha, bisabolol, cis-14-nor-muurol-5-en-4-one, (E,E)-farnesol).

The hydrodistilled essential oils (EOs) from flowers of five Adriatic populations of Anthemis maritima were analyzed by GC-FID and GC/MS. Anthemis maritima is a psammophilous plant living generally on coastal sand dunes but occasionally on sea cliffs and shingle beaches. A total of 163 chemical compounds were identified, accounting for 90.5% of the oils. The main classes of compounds represented in the EOs were monoterpene hydrocarbons, oxygenated monoterpenes, sesquiterpene hydrocarbons, oxygenated sesquiterpenes, and terpene esters.The multivariate chemometric techniques, in particular cluster analysis and principal coordinate analysis, used to classify the samples, highlighted three different chemotypes linked to a geographic origin. One group living in northern Italy was characterized by the highest content of β-pinene, γ-terpinene, and β-caryophyllene, a second chemotype was in central Italy with the highest amount of trans-chrysanthenyl acetate and a third group living in southern Italy with a more heterogeneous volatile profile was characterized by the highest values of cis-chrysanthenyl acetate, trans-chrysanthenyl isobutyrate, cis-carveol propionate, α-zingiberene, and cubenol. Moreover, the comparison of the Adriatic populations with the Tyrrhenian samples, analyzed in a previous research, showed that cubenol (absent in all the Tyrrhenian populations) and (E)-β-farnesene (absent in all the Adriatic samples) play a crucial role in discriminating the Italian populations.

The oils extracted by hydro distillation from the aerial parts of Artemisia scoparia waldst. & kitag growing wild in two regions on Qinghai-Tibetan Plateau were analyzed by GC-MS. Eighty-three components were identified representing 97.5% of the total components detected. The major constituents of the oil from the samples obtained in the eastern of Riyue Mountain (2700 - 3200 m) were 2-ethenyl-naphthalene (45.1%), beta-pinene (11.2%), 3-carene (8.7%), 3,7-dimethyl-1,3,6- octatriene (7.9%), limonene (5.4%), alpha-pinene (3.5%) and beta-myrcene (2.0%). Whereas the oil from the plant collected in Qilian Mountain (3300 - 3500 m) was composed mainly of thujone (21.4%), 1,8-cineole (18.9%), camphor (9.1%), 4-methyl-1-(1-methyl ethyl)-3-cyclo hexen-1-ol (7.8%), 4-methyl-1-(1-methylethyl)-bicyclo[3.1.0]hexan-3-one (5.3%) and 2-isopropyl-5-methyl- 3-cyclohexen-1-one(5.0%).

The growing demand and commercial value of black pepper (Piper nigrum) has resulted in considerable interest in developing suitable and cost-effective methods for chemical characterization and quality evaluation purposes. In the current study, an extensive set of oil samples (n = 23) that were extracted by steam distillation from black pepper seeds was investigated to compare the chemical profiles of samples originating from nine major producing countries, as well as to identify potential chemical markers for quality evaluation. The twenty-two most abundant volatile compounds, mainly terpenes, in these oils were determined by conventional GC/MS analysis. Principal component analysis with this set of data revealed distinct clusters for samples that originated from China and Malaysia. Relatively low concentrations of sabinene (

Essential oils (EOs) were obtained by hydrodistillation of various parts of Ferula ovina (Boiss.) Boiss., Ferula iliensis Krasn. ex. Korovin, and Ferula akitschkensis B. Fedtsch. ex Koso-Pol., collected in the flowering/budding and fruiting stages. Eight samples of EOs isolated from F. ovina and four samples from F. akitsckensis were analyzed by gas chromatography&ndash, mass spectrometry (GC-MS). The major constituents of F. ovina EOs were &alpha, pinene (6.9&ndash, 47.8%), &beta, pinene (1.5&ndash, 7.1%), sabinene (0.1&ndash, 20.5%), &beta, phellandrene (0&ndash, 6.5%), trans-verbenol (0.9&ndash, 7.4%), eremophilene (3.1&ndash, 12%), and 6Z-2,5,5,10-tetramethyl-undeca-2,6,9-trien-8-one (0&ndash, 13.7%). The major constituents of F. akitsckensis EOs were &alpha, pinene (0&ndash, 46.2%), &beta, 47.9%), sabinene (0&ndash, 28.3%), eremophilene (0&ndash, 10.6), &beta, caryophyllene (0&ndash, 7.5%), himachalen-7-ol (0&ndash, 28.2%), and an himachalol derivative (0&ndash, 8.3%). Samples of EOs from F. ovina, F. iliensis, and F. akitsckensis were evaluated for antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) pulse-field gel electrophoresis type USA300 (LAC). EOs from F. ovina exhibited the highest antibacterial activity compared to samples from other Ferula spp., with the most potent EOs being isolated from roots at the flowering and fruiting stages and stems at the fruiting stage (IC50 values of 19.1, 20.9, and 22.9 &micro, g/mL, respectively). Although EOs demonstrated concentration-dependent inhibition of MRSA growth, analysis of the major constituents (&alpha, pinene, &beta, pinene, and sabinene) showed that they had low activity, suggesting that other components were likely responsible for the observed bioactivity of the unfractionated EOs. Indeed, correlation of the GC-MS data with antibacterial activity suggested that the putative components responsible for antibacterial activity were, either individually or in combination, eremophilene and trans-verbenol. Overall, these results suggest that the EOs from F. ovina could have potential for use as alternative remedies for the treatment of infectious diseases caused by MRSA.

Extracts of essential oils have various properties in different applications This work focuses on the chemical characterization of the aromatic compositions of two citrus species Citrus Aurantium CA and Citrus Reticulata CR which belongs to the Rutaceae family The essential oils were extracted by hydro distillation of the aerial parts stems leaves and flowers of citrus and analyzed by gas chromatography mass spectrometry GC MS Linalool alpha terpineol gamma Terpinene cis Linalool oxide Nerol Caryophyllene oxide Carvacrol beta Citronellol Spathulenol beta pinene and beta Oplopenone were obtained as majority compounds with a percentage of In essential oil of Citrus Aurantium CA Limonene gamma Terpinene Nerol and alpha pinene were obtained as major compounds with a percentage of The highest yields were recorded with Citrus Aurantium CA and Citrus Reticulata CR

Main conclusionSynechocystis (a cyanobacterium) was employed as an alternative host for the production of plant essential oil constituents. β-Phellandrene synthase (PHLS) genes from different plants, when expressed in Synechocystis, enabled synthesis of variable monoterpene hydrocarbon blends, converting Synechocystis into a cell factory that photosynthesized and released useful products. Monoterpene synthases are secondary metabolism enzymes that catalyze the generation of essential oil constituents in terrestrial plants. Essential oils, including monoterpene hydrocarbons, are of interest for their commercial application and value. Therefore, heterologous expression of monoterpene synthases for high-capacity essential oil production in photosynthetic microorganism transformants is of current interest. In the present work, the cyanobacterium Synechocystsis PCC 6803 was employed as an alternative host for the production of plant essential oil constituents. As a case study, β-phellandrene synthase (PHLS) genes from different plants were heterologously expressed in Synechocystis. Genomic integration of individual PHLS-encoding sequences endowed Synechocystis with constitutive monoterpene hydrocarbons generation, occurring concomitant with photosynthesis and cell growth. Specifically, the β-phellandrene synthase from Lavandula angustifolia (lavender), Solanum lycopersicum (tomato), Pinus banksiana (pine), Picea sitchensis (Sitka spruce) and Abies grandis (grand fir) were active in Synechocystis transformants but, instead of a single product, they generated a blend of terpene hydrocarbons comprising β-phellandrene, α-phellandrene, β-myrcene, β-pinene, and δ-carene with variable percentage ratios ranging from 90% in different product combinations and proportions. Our results suggested that PHLS enzyme conformation and function depends on the cytosolic environment in which they reside, with the biochemical properties of the latter causing catalytic deviations from the products naturally observed in the corresponding gene-encoding plants, giving rise to the terpene hydrocarbon blends described in this work. These findings may have commercial application in the generation of designer essential oil blends and will further assist the development of heterologous cyanobacterial platforms for the generation of desired monoterpene hydrocarbon products.

Beauty bush' and twin flower' are common names attributed to two well-recognizable species belonging to the genus Linnaea (16 spp.) - L. amabilis and L. borealis - long admired by botanists and gardeners for their perfumed paired bell-shaped flowers. In the present study, we investigated their floral scent compositions through gas chromatography - mass spectrometry (GC-MS) analysis of dynamic headspace samples. Because the flowers of L. borealis in wild populations are fragrant both during the day and in the evening, circadian variation of scent emission was also assessed for this species. In total, 26 chemical compounds comprise the floral scent bouquets of L. amabilis and L. borealis, identified as monoterpenes (14), benzenoids and phenylpropanoids (5), aliphatics (3), sesquiterpenes (3) and irregular terpenes (1). Whereas monoterpenes, notably (-)-- and -pinene, dominated the scent of L. amabilis (over 82% relative abundance), benzene derivates: 1,4 dimethoxybenzene, anisaldehyde, 2-phenylethanol, benzaldehyde and nicotinaldehyde were exclusive to analysed headspace samples of L. borealis, accounting for 52% to 100% of their relative compositions, in three Swedish populations. A southwestern Finnish population was characterized by the four first mentioned benzenoid compounds and large amounts of (-)-- and -pinenes plus two aliphatic substances. The scent compounds identified for both species are ubiquitous and may serve as generalist attractants/stimulants for a broad assortment of anthophilous insects. The basic work on the flower scent of L. amabilis and L. borealis should inspire studies of their pollination biology, primarily the behaviour-guiding roles of the characteristic emitted volatiles.

Stable high-molecular-weight esters are present in α-pinene ozonolysis secondary organic aerosol (SOA) with the two most abundant ones corresponding to a hydroxypinonyl ester of cis-pinic acid with a molecular weight (MW) of 368 (C19H28O7) and a diaterpenylic ester of cis-pinic acid with a MW of 358 (C17H26O8). However, their molecular structures are not completely elucidated and their relationship with highly oxygenated molecules (HOMs) in the gas phase is still unclear. In this study, liquid chromatography in combination with positive ion electrospray ionization mass spectrometry has been performed on high-molecular-weight esters present in α-pinene ozonolysis SOA with and without derivatization into methyl esters. Unambiguous evidence could be obtained for the molecular structure of the MW 368 ester in that it corresponds to an ester of cis-pinic acid where the carboxyl substituent of the dimethylcyclobutane ring and not the methylcarboxyl substituent is esterified with 7-hydroxypinonic acid. The same linkage was already proposed in previous work for the MW 358 ester (Yasmeen et al., 2010), but could be supported in the present study. Guided by the molecular structures of these stable esters, we propose a formation mechanism from gas-phase HOMs that takes into account the formation of an unstable C19H28O11 product, which is detected as a major species in α-pinene ozonolysis experiments as well as in the pristine forest atmosphere by chemical ionization–atmospheric pressure ionization–time-of-flight mass spectrometry with nitrate clustering (Ehn et al., 2012, 2014). It is suggested that an acyl peroxy radical related to cis-pinic acid (RO2⚫) and an alkoxy radical related to 7- or 5-hydroxypinonic acid (R′O⚫) serve as key gas-phase radicals and combine according to a RO2 + R′O⚫ → RO3R′ radical termination reaction. Subsequently, the unstable C19H28O11 HOM species decompose through the loss of oxygen or ketene from the inner part containing a labile trioxide function and the conversion of the unstable acyl hydroperoxide groups to carboxyl groups, resulting in stable esters with a molecular composition of C19H28O7 (MW 368) and C17H26O8 (MW 358), respectively. The proposed mechanism is supported by several observations reported in the literature. On the basis of the indirect evidence presented in this study, we hypothesize that RO2 + R′O⚫ → RO3R′ chemistry is at the underlying molecular basis of high-molecular-weight ester formation upon α-pinene ozonolysis and may thus be of importance for new particle formation and growth in pristine forested environments.

Atmospheric aerosol particles affect the quality of life by influencing climate and by being a significant component of air pollution. Once a particle is released into or formed in the atmosphere, several processes begin to transform its physical and chemical properties. A considerable fraction of the particulate matter is secondary material i.e. formed from gas-to-particle conversion in the atmosphere. This secondary particle formation is an important process in the evolution of atmospheric aerosols. The aim of this thesis is to study the formation and aging of secondary aerosols by experimentally simulating atmospheric oxidation of emissions from biogenic and traffic-related sources. In this work the focus is on particle size, mass and number concentration, as well as on the thermal properties of the particles formed. These measures give insight into properties relevant for understanding the evolution of particles in the ambient atmosphere. The thermal properties of secondary organic aerosols (SOA) formed from oxidation of monoterpenes in two oxidation flow reactors, G-FROST and PAM, and the atmospheric simulation chamber SAPHIR, was studied using a Volatility Tandem DMA (VTDMA). The detailed laboratory studies show that the formation of monoterpene SOA and its thermal properties depend on chemical structure of the precursor and oxidizing conditions. Furthermore, freshly formed monoterpene SOA comprise of compounds with a wide distribution of volatilities ranging from extremely low volatile to semi volatile compounds. Photochemical aging of SOA was studied in SAPHIR by oxidation induced by natural sun light and in PAM by exposing SOA precursors to high concentration of OH over a short time. The results reveal two opposing processes which drive the evolution of SOA volatility in the two systems. During the course of this work an oxidation flow reactor, Go:PAM, has been developed. Go:PAM enables studies of secondary particle formation from rapidly changing emission sources, and was used to derive fuel-specific secondary particle emission factors from in-use transit buses under real-world driving conditions. Both primary emissions and the secondary particle formation of 29 buses running on conventional or on more sustainable fuels were investigated. The results emphasize the importance of taking the reduction in OH exposure into consideration when interpreting the secondary particle formation from plumes. However, independent of fuel and technology of the buses, the formation of secondary particulate mass was significantly higher than the primary particle mass. Furthermore, the results indicate there are emissions of non-fuel related compounds that are important for secondary particle formation. This work provides insight in the formation and aging of secondary particles from biogenic and traffic-related sources. The results highlight the importance of including secondary particle formation when predicting the climate forcing of SOA and designing of air quality strategies.