Monoterpene Fraction Research Articles

Comparison of Urban Air Quality Simulations During the KORUS‐AQ Campaign With Regionally Refined Versus Global Uniform Grids in the Multi‐Scale Infrastructure for Chemistry and Aerosols (MUSICA) Version 0

AbstractModel intercomparison studies often report a large spread in simulation results, but quantifying the causes of these differences is hindered by the fact that several processes contribute to the model spread simultaneously. Here we use the Multi‐Scale Infrastructure for Chemistry and Aerosols (MUSICA) version 0 to investigate the model resolution dependencies of simulated chemical species, with a focus on the differences between global uniform grid and regional refinement grid simulations with the same modeling framework. We construct two global (ne30 [∼112 km] and ne60 [∼56 km]) and two regional refinement grids over Korea (ne30x8 [∼14 km] and ne30x16 [∼7 km]). The grid resolution can change chemical concentrations by an order of magnitude in the boundary layer, and the importance increases as the species' reactivity increases (e.g., up to 50% and 1,000% changes for ethane and xylenes, respectively). The diurnal cycle of oxidants (OH, O3, and NO3) also varies with the grid resolution, which leads to different oxidation pathways of volatile organic compounds (e.g., the fraction of monoterpenes reacting with NO3 in Seoul around midnight is 90% for ne30, but 65% for ne30x16). The models with high‐resolution grids usually do a better job at reproducing aircraft observations during the KORUS‐AQ campaign, but not always, implying compensating errors in the coarse grid simulations. For example, ozone is better reproduced by the coarse grid due to the artificial mixing of NOx. When developing new chemical mechanisms and evaluating models over urban areas, the uncertainties associated with model resolution should be considered.

Ubiquity of Anthropogenic Terpenoids in Cities Worldwide: Emission Ratios, Emission Quantification and Implications for Urban Atmospheric Chemistry

AbstractTerpenoids (isoprene and monoterpenes) are highly reactive Volatile Organic Compounds (VOCs) known for decades for their biogenic origin. Here, we discuss the nature and magnitude of their anthropogenic emissions. We compiled and re‐analyzed 14 data sets of in situ VOC observations collected over the last decade in contrasting urban areas from mid‐latitudes to subtropical regions. We show the systematic presence of anthropogenic terpenoids in urban ambient air with clear covariations with anthropogenic compounds (R2 > 0.50) even during mid‐latitude winters. Despite the emerging importance of monoterpene emissions from consumer products in North American cities, there is some evidence of monoterpene emissions from tailpipe exhaust in cities of the developing world. The traffic‐related fraction of monoterpenes is estimated and can account for up to 40% of their ambient levels. The anthropogenic emission ratios (ER) of some terpenoids (isoprene, α‐pinene and limonene) are estimated and spatially compared. The anthropogenic emissions of terpenoids are indirectly estimated from those ER combined to regional and global emission inventories (CAMS‐GLOB‐ANT_v4.2) at urban and country scale focusing on France, Lebanon, and Vietnam. Those anthropogenic emissions do not represent more than 3% of other anthropogenic VOC emissions. However, they dominate by one to three orders of magnitude the reactivity of other anthropogenic VOCs regarding NO3 oxidation and ozonolysis. This study raises two questions which need further investigations in the future: (a) the significance of terpenoid emissions from traffic, especially in urban areas of the developing world and (b) the role of anthropogenic terpenoids in nighttime and wintertime atmospheric chemistry at mid‐latitudes.

A Comparative Study on Chemical Compositions and Biological Activities of Four Amazonian Ecuador Essential Oils: Curcuma longa L. (Zingiberaceae), Cymbopogon citratus (DC.) Stapf, (Poaceae), Ocimum campechianum Mill. (Lamiaceae), and Zingiber officinale Roscoe (Zingiberaceae).

Essential oils (EOs) and their vapour phase of Curcuma longa (Zingiberaceae), Cymbopogon citratus (Poaceae), Ocimum campechianum (Lamiaceae), and Zingiber officinale (Zingiberaceae) of cultivated plants grown in an Amazonian Ecuador area were chemically characterised by Gas Chromatography-Flame Ionization Detector (GC-FID), Gas Chromatography-Mass Spectrometry (GC-MS), and Head Space-Gas Chromatograph-Flame Ionization Detector-Mass Spectrometry (HS-GC-FID-MS).figure The EOs analyses led to the identification of 25 compounds for C. longa (99.46% of the total; ar-turmerone: 23.35%), 18 compounds for C. citratus (99.59% of the total; geraniol: 39.43%), 19 compounds for O. campechianum (96.24% of the total; eugenol: 50.97%), and 28 for Z. officinale (98.04% of the total; α-Zingiberene: 15.45%). The Head Space fractions (HS) revealed C. longa mainly characterised by limonene and 1,8-cineole (37.35%) and α-phellandrene (32.33%); Z. officinale and C. citratus showed camphene (50.39%) and cis-Isocitral (15.27%) as the most abundant compounds, respectively. O. campechianum EO revealed a higher amount of sesquiterpenes (10.08%), mainly characterised by E-caryophyllene (4.95%), but monoterpene fraction remained the most abundant (89.94%). The EOs were tested for antioxidant, antimicrobial, and mutagen-protective properties and compared to the Thymus vulgaris EO as a positive reference. O. campechianum EO was the most effective in all the bioactivities checked. Similar results emerged from assaying the bioactivity of the vapour phase of O. campechianum EO. The antioxidant and antimicrobial activity evaluation of O. campechianum EO were repeated through HP-TLC bioautography assay, pointing out eugenol as the lead compound for bioactivity. The mutagen-protective evaluation checked through Ames's test properly modified evidenced a better capacity of O. campechianum EO compared with the other EOs, reducing the induced mutagenicity at 0.1 mg/plate. However, even with differences in efficacy, the overall results suggest important perspectives for the functional use of the four studied EOs.

Chemical Approach to the Optimization of Conditions Using HS-SPME/GC-MS for Characterization of Volatile Compounds in Eugenia brasiliensis Fruit.

Grumixama (Eugenia brasiliensis Lam.) is a native fruit of the Brazilian Atlantic Forest, belonging to the Myrtaceae family, which designatesthe most significant number of species with food potential. It stands out due to its phytochemical characteristics because of the presence of polyphenols and volatile organic compounds. Volatile compounds are substances released by foods that give off an aroma and influence flavor. Solid-phase microextraction is a technique that allows for low-cost, fast, and solvent-free extraction, has an affinity for numerous analytes, and is easily coupled to gas chromatography. The objectives of this work were to evaluate the efficiency of different fibers of SPME (solid-phase microextraction) in the extraction of volatile organic compounds from grumixama pulp; optimize a method for extraction time, temperature, and sample weight; and to determine the characteristic volatile profile of this fruit. For the extraction of volatile compounds, three fibers of different polarities were used: polar polyacrylate (PA) fibers, divinylbenzene/carboxyne/polydimethylsiloxane (DVB/CAR/PDMS) semipolar fibers, and polydimethylsiloxane/divinylbenzene (PDMS/DVB). Fourteen volatile organic compounds (VOCs) were identified by DVB/CAR/PDMS, six by PA, and seven by PDMS/DVB through solid-phase microextraction in the headspace mode (SPME-HS). Considering the total number of compounds identified, regardless of the fiber used, and the optimization of the method, Eugenia brasiliensis presented sesquiterpene fractions (85.7%, 83.3%, and 85.7% of total VOCs) higher than the monoterpene fractions (14.3%, 16.7%, and 14.3%) for DVB/CAR/PDMS, PA, and PDMS/DVB, respectively in its composition. In addition, it was possible to verify that the fiber DVB/CAR/PDMS presented a better efficiency due to the larger chromatographic area observed when the grumixama pulp was subjected to conditions of 75 °C, 2.0 g, and an adsorption time of 20 min.

СОСТАВ ЭФИРНОГО МАСЛА И АНТИРАДИКАЛЬНАЯ АКТИВНОСТЬ СОСНЫ ОБЫКНОВЕННОЙ ШИШЕК, ЗАГОТОВЛЕННЫХ В ПЕРМСКОМ КРАЕ

Abstract. Scots pine is a widespread plant on the territory of the Russian Federation. Scots pine cones are thought of as an advanced raw material for the research of the chemical composition and pharmacological activity. The object of this paper was the research of the essential oil component composition and antioxidative activity of young Scots pine cones collected in the Perm region. The samples of Scots pine cones were collected in the Yurlinsky, Ilyinsky, Permsky and Bardymsky districts of the Perm Region for the essential oil component composition research. The essential oil component composition was determined by the gas chromatograph with a mass selective detector Agilent 7890A. The antioxidative activity of raw materials infusions was determined by their ability to bind the free radical 2,2-diphenyl-1-picrylhydrazyl. As a result of the research, 10 components related to monoterpenes and sesquiterpenes were identified in the essential oil of Scots pine cones of all regions. The monoterpene fraction predominates in the essential oil of Scots pine cones in all districts of the research. The content of sesquiterpenes slightly increases in the essential oil of the more southern districts of the region, such as Permsky and Bardymsky. The content of sesquiterpenes in the essential oil of more southern districts grows mainly due to an increase of caryophyllene and humulene. The main component of Scots pine cones essential oil is the dicyclic monoterpene α-pinene. Basing on the results of the antioxidative activity determination, it was found that the infusions prepared from young pine cones collected in the Ilyinsky, Bardymsky and Permsky districts have the maximal ability to bind free radicals. The infusion of the pine cones from the Yurlinsky district has showed the least antioxidative activity, which can be ascribed to a high content of the monoterpene fraction in the essential oil.

Chemical Composition and Antibacterial Properties of Essential Oil Extracted from the Leaves and the Rhizomes of Stahlianthus thorelii Gagnep. (Zingiberaceae)

Stahlianthus thorelii Gagnep. is a plant belonging to the family Zingiberaceae, widely distributed in Asian countries like China, Thailand, India and Vietnam. In traditional oriental medicine, this plant is usually used to treat hemorrhage, heavy menstruation, poor digestion, rheumatism and bone / joint pain (tuberous roots). For the first time, the essential oils from the leaves and the rhizomes of S. thorelii collected in Vietnam were analyzed by Gas Chromatography-coupled with Mass Spectrometry (GC/MS) and investigated for their in vitro anti-microbacterial activity against several Gram (+) / (-) bacteria, fungi and yeast. A total of twenty and thirty components were detected accounting for 81.5 % and 95.5 % of the rhizome and leaf oils, respectively. These volatile compounds were identified as a complex of monoterpene fractions (14.2 % / 9.4 %) and mainly sesquiterpenes (60.0 % / 63.9 %) respectively. The most abundant sesquiterpenes in rhizome were found to be α-copaene (32.2 %) and (-)-allo-aromadendrene (11.3 %) while these compounds in leaves were identified only as 5.0 % and 5.3 %, respectively. In the antibacterial tests, the rhizome oil at MIC 150-200 μg/ml exhibited distinct activity against the Gram (+) bacteria Bacillus subtilis, Staphylococcus aureus, and the fungi Aspergillus niger. While the oil obtained from leaves at MIC 200 μg/ml showed inhibitory activity against B. subtillis.

Soil parameters and bioclimatic characteristics affecting essential oil composition of leaves of Pistacia lentiscus L. from València (Spain)

The variability of the soils found in an area together with the diversity of the bioclimatic parameters will affect the chemical profile of plant species, in our case <em>Pistacia lentiscus</em> L. The aim of this work is to analyse the bioclimatic characteristics and soil parameters affecting the essential oil (EO) composition of the leaves of the <em>Pistacia lentiscus</em> L. growing in València (Spain). The EO compositions of dried leaves of <em>Pistacia lentiscus</em> L. from five sampling sites with noticeable differences in soil and climate features were analysed by GC(MS) and GD(FID). The main bioclimatic and soil parameters were also determined in order to relate them to oil composition. a-pinene (2.8-39.2%), myrcene (0.6-59.3%), b-phellandrene (0.0-42.8%), germacrene-D (3.9-20.4%) and terpinen-4-ol (0.2-19.0%) were found to be the major compounds showing a high variability. The five sampling sites presented well-defined bioclimatic and edaphic characteristics that could be related to specific EO profiles. The results suggested that the EO composition of <em>P. lentiscus</em> L. depends more on the edaphic factors interacting with bioclimate conditions than on the geographical origin itself. Some general trends could be established based on the results: the Calcaric Arenosol (Saler) with a high evapotranspiration index was associated with a high sesquiterpenic fraction, (germacrene-D and b-caryophyllene, mainly). The Luvisol (Borrell and L’Ull), with high amounts of a + b-pinene, were found to be related to sub-humid bioclimatic conditions and clayey and fertile soils (high CEC and OM levels). This last requirement was also observed to be related to the myrcene content, but with drier climatic conditions and calcareous soils (Haplic Calcisol) with high level of carbonates and active lime (Lliria). The rest of hydrocarbon monoterpene and oxygenated monoterpene (terpinen-4-ol, mainly) fractions could be related to a dry climate and non-calcareous and low fertility soils (Eutric Regosol, Segart). Given the most suitable composition related to specific and useful biological activities, new research of controlled environmental factors (soil features and bioclimatic conditions) should be conducted in order to define the best conditions to manage industrial crops of <em>P. lentiscus </em>L<em>.</em>

Contribution to the study of the chemical variability of the essential oils of the seeds and the stems in some populations of Pituranthos tortuosus (Coss.) Maire from Tunisia

The aim of this study was to investigate the variation of the chemical composition of the seeds and stems essential oils of Pituranthos tortuosus (Coss.) Maire collected from three regions of Tunisia (Bousaid (Sfax), Rgeb (Sidi Bouzid) and Majoura (Gafsa)). The seeds and the stems were hydrodistillated during 4 h by using a Clevenger-type apparatus. The obtained essential oils were analyzed by GC and GC-EI-MS. The chromatographic analysis indicated the detection of sixty-seven components accounting from 97.5% to 99.7% of the whole of each essential oil with a predominance of monoterpene hydrocarbons (from 38.2% to 66.1%). So, a strong predominance of the monoterpene fraction was observed in the seeds (75.8%; 60.6%; 90.8%) and the stems (89.7%; 91.7%; 89.7%) essential oil of P. tortuosus collected from Majoura, Bousaid and Rgeb, respectively. However, sabinene (19.4%; 11.8%; 24.7%) and terpinen-4-ol (16.9%; 22.9%; 19.2%) were the most abundant compounds of the essential oil of seeds and stems of Rgeb as well as the essential oil of the stems of Majoura, respectively, whereas the major components of the seeds of P. tortuosus collected from Majoura were limonene (25.1%), sabinene (18.6%) and apiol (13.4%). The stems essential oils of Bousaid were dominated by terpinen-4-ol (32.3%), sabinene (23.6%) and p-cymene (10.9%) while dillapiole (34.7%), limonene (14.3%), sabinene (12.6%) and terpinen-4-ol (10.4%) were the main components of the essential oil of the seeds collected from Bousaid. Based on the main compounds, the essential oils of seeds and stems of P. tortuosus from the three regions of Tunisia displayed different chemical compositions.

Seasonal Variation of Biogenic and Anthropogenic VOCs in a Semi-Urban Area Near Sydney, Australia

Volatile organic compounds (VOCs) play a key role in the formation of ozone and secondary organic aerosol, the two most important air pollutants in Sydney, Australia. Despite their importance, there are few available VOC measurements in the area. In this paper, we discuss continuous GC-MS measurements of 10 selected VOCs between February (summer in the southern hemisphere) and June (winter in the southern hemisphere) of 2019 in a semi-urban area between natural eucalypt forest and the Sydney metropolitan fringe. Combined, isoprene, methacrolein, methyl-vinyl-ketone, α-pinene, p-cymene, eucalyptol, benzene, toluene xylene and tri-methylbenzene provide a reasonable representation of variability in the total biogenic VOC (BVOC) and anthropogenic VOC (AVOC) loading in the area. Seasonal changes in environmental conditions were reflected in observed BVOC concentrations, with a summer peak of 8 ppb, dropping to approximately 0.1 ppb in winter. Isoprene, and its immediate oxidation products methacrolein (MACR) and methyl-vinyl-ketone (MVK), dominated BVOC concentrations during summer and early autumn, while monoterpenes comprised the larger fraction during winter. Temperature and solar radiation drive most of the seasonal variation observed in BVOCs. Observed levels of isoprene, MACR and MVK in the atmosphere are closely related with variations in temperature and photosynthetically active radiation (PAR), but chemistry and meteorology may play a more important role for the monoterpenes. Using a nonlinear model, temperature explains 51% and PAR 38% of the isoprene, MACR and MVK variation. Eucalyptol dominated the observed monoterpene fraction (contributing ~75%), with p-cymene (20%) and α-pinene (5%) also present. AVOCs maintain an average concentration of ~0.4 ppb, with a slight decrease during autumn–winter. The low AVOC concentrations observed indicate a relatively small anthropogenic influence, generally occurring when (rare) northerly winds transport Sydney emissions to the measurement site. The site is influenced by domestic, commercial and vehicle AVOC emissions. Our observed AVOC concentrations can be explained by the seasonal changes in meteorology and the emissions in the area as listed in the NSW emissions inventory and thereby act as an independent validation of this inventory. We conclude that the variations in atmospheric composition observed during the seasons are an important variable to consider when formulating air pollution control policies over Sydney given the influence of biogenic sources during summer, autumn and winter.

Chemotypic structure of Pinus sylvestris population in Usmansky and Khrenovskoy pine forests

The main target of the paper is to study structure of main pine forest types in Usmansky and Khrenovskoy pine forests, their chemical composition of essential oil (EO) monoterpene fraction. This paper is on problems of Scots Pine (Pinus sylvestris) breeding and seed-growing in the forest-steppe European part. It is done for forest culture improvement, based on genetics and breeding. The characteristic of main components of pine-needles essential oil in free and controlled cross-breeding was investigated. The established peculiarities of monoterpene biosynthesis in pine-needless essential oil are genetically motivated. The long-term opportunity for essential oil composition usage as characteristics of Pinus sylvestris breeding on resistibility to diseases and pests was defined. The structures of main forest types in Usmansky and Khrenovskoy pine forests according to basic monometric and biochemical indices were studied. The data on composition, changeability and inheritance regularity of monoterpenes may be used for recommendations on creating of Pinus sylvestris seed base on genetic and breeding bases.

Composition and Anti-inflammatory Effect of the Common Myrtle’s (Myrtus communis L.) Essential Oil Growing Wild in Algeria

This study was designed to evaluate the chemical composition and anti-inflammatory activity of the common myrtle essential oil (Myrtus communisL.). The essential oil composition ofMyrtus communisL. extracted by steam distillation was characterized by a high oxygenated monoterpene fraction (80.9%). The major components were myrtenyl acetate (38.7%), eucalyptol (12.7%), α-pinene (13.7%), and linalool (7.00%). The chemical profile of this essential oil allows us to classify it as myrtényle acétate/α-pinène chemotype, but with atypical proportions, related to the harvesting area. In the carrageenan-induced paw edema, five different groups were established and the essential oil was administered orally in three different doses. The common myrtle essential oil (100 mg/kg) was able to reduce the paw edema, with a comparable effect to that observed with Diclofenac (positive control). This is the first report to demonstrate a significant anti-inflammatory activity of Algerian common myrtle essential oil.

Chemical composition and antimicrobial activity of essential oil of Helichrysum italicum (Roth) G. Don fil. (Asteraceae) from Montenegro

An experimental investigation on essential oil of a Montenegrin Helichrysum italicum (Roth) G. Don fil. (Asteraceae) is reported. The essential oil was analysed in both liquid and vapour phases. Gas chromatography-mass spectrometry analysis of the liquid oil showed the predominance of sesquiterpenes with β-eudesmene (21.65%) and β-bisabolene (19.90%) as the major ones. Monoterpene fraction was mainly represented by α-pinene (16.90%) and neryl acetate (10.66%). Head-space technique revealed the vapour phase enriched of monoterpenes with α-pinene (78.76%) predominance. The essential oil was tested against methicillin-sensitive Staphylococcus aureus (ATCC 29213), Escherichia coli (ATCC 25922), Candida albicans (ATCC 14053) and the clinical strains of methicillin-resistant S. aureus, carbapenem-resistant Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii and carbapenem-resistant Pseudomonas aeruginosa. Interesting fungicidal/bactericidal potency against C. albicans and carbapenem-resistant A. baumannii was revealed at concentration of 5% v/v.

Phytochemistry of Three Ecuadorian Lamiaceae: Lepechinia heteromorpha (Briq.) Epling, Lepechinia radula (Benth.) Epling and Lepechinia paniculata (Kunth) Epling.

In this research, the leaves of Lepechinia heteromorpha (Briq.) Epling, Lepechinia radula (Benth.) Epling and Lepechinia paniculata (Kunth) Epling have been collected in order to perform a phytochemical study. The first species was distilled to obtain a novel essential oil (EO), while the others were submitted to ethyl acetate extraction and secondary metabolite isolation. The chemical composition of the EO from L. heteromorpha has been investigated by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography with Retention Indices (GC(RI)), identifying 25 constituents. A major compound, (−)-ledol (21.2%), and a minor compound, (−)-caryophyllene oxide (1.0%), were isolated from the EO and their structures confirmed by Nuclear Magnetic Resonance (NMR) spectroscopy. Other major constituents of the EO were viridiflorene (27.3%), (E,E)-α-farnesene (1.4%), spirolepechinene and (E)-β-caryophyllene (7.1% each), allo-aromadendrene (6.1%), camphor (1.7%), limonene (1.3%) and β-phellandrene (4.6%). The enantiomeric composition of the EO monoterpene fraction was also studied, determining the enantiomeric excess and distribution of α-pinene, limonene, β-phellandrene and camphor. The ethyl acetate extract of L. radula and L. paniculata were fractionated by column chromatography. Spathulenol, angustanoic acid E and 5-hydroxy-4′,7-dimethoxy flavone were isolated from L. radula extract; ledol, guaiol and (−)-carnosol were found in L. paniculata.

The importance of cylinder passivation for preparation and long-term stability of multicomponent monoterpene primary reference materials

Abstract. Monoterpenes play an important role in atmospheric chemistry due to their large anthropogenic and biogenic emission sources and high chemical reactivity. As a consequence, measurements are required to assess how changes in emissions of monoterpenes impact air quality. Accurate and comparable measurements of monoterpenes in indoor and outdoor environments require gaseous primary reference materials (PRMs) that are traceable to the international system of units (SI). PRMs of monoterpenes are challenging to produce due to the high chemical reactivity and low vapour pressures of monoterpenes and also their propensity to convert into other compounds, including other terpenes. In this paper, the long-term stability of gravimetrically prepared static monoterpene PRMs produced in differently passivated cylinders, including sampling canisters, was assessed. We demonstrate that static PRMs of multiple monoterpenes can be prepared and used as a suitable long-term standard. For the first time the effect of cylinder pressure and decanting from one cylinder to another on the chemical composition and amount fraction of monoterpenes was also studied. Gravimetrically prepared PRMs of limonene in high pressure cylinders were compared to a novel portable dynamic reference gas generator based on dilution of pure limonene vapour emitted from a permeation tube.

HS-SPME/GC/GC-MS Analysis of Volatile Constituents of Morina longifolia Wall.

The headspace (HS) composition of volatile compounds of leaf essential oil of medicinally important Morina longifolia Wallich (Wall.) was investigated by solid-phase microextraction/gas chromatography/flame ionization detector (SPME/GC/FID), and GC/mass spectrometry (MS). Forty six compounds (> 0.1 %) representing 96.20 % of the relative peak area of total chromatogram were detected. The oil was rich in sesquiterpene hydrocarbons with nineteen constituents amounting to 57.40 % of the oil with germacrene D (31.10 %) and α-humulene (5.50 %), as major constituents while trans-crysanthenyl acetate (4.50 %) and β-Phellandrene (3.60 %) were the main compounds in the monoterpene fraction (17.30 %). The results of study indicate the possible use of the volatile fraction of leaves essential oil of M. longifolia as a source of germacrene-D, a sesquiterpene of high perfumery value. The proposed HS-SPME method can also be applied to routine control analysis of aromatic and medicinal plants.

Exploring of bioactive compounds in essential oil acquired from the stem and root derivatives of Hypericum triquetrifolium callus cultures

The chemical profile of the essential oil of callus and cell suspension cultures derivatives from stem and root of Hypericum triquetrifolium were explored by ITEX/GC-MS. The major constituents for stem derivatives were undecane (78.44%) and 2,4,6-trimethyl-octane (9.74%) for fresh calli, 2,4-dimethyl-benzaldehyde (46.94%), 2,3-dimethyl-undecane (28.39%), 2,4-dimethyl-1-hexene (10.17%), 1,2-oxolinalool (3.64%) and limonene (3.55%) for dry calli and undecane (61.24%), octane, 2,4,6-trimethyl- (16.73%), nonane, 3-methyl-(3.74%), 2,5-diphenyl-benzoquinone (3.70%) and limonene (3.60%) for cell suspension. However, for root derivatives, the dominated components were: undecane (49.94%), eucalyptol (12.07%), limonene (9.98%), toluene (9.03%) and 3-methyl-nonane (4.29%) for fresh calli, 2,4-dimethyl-benzaldehyde (29.80%), 1,1-dimethylethyl-cyclohexane (14.99%), 3-methyl-pentanal (14.99%), undecane (10.04%), beta-terpinyl acetate (8.60%), 1,2-oxolinalool (6.27%) and 2-pentyl-furan (4.09%) for dry calli, undecane (52.38%), 2,4,6-trimethyl-octane (13.81%), 3-methyl-nonane (5.73%), toluene (4.82%) and limonene (4.57%) for cell suspension derivative in root. The attained outcomes indicated that the alkane, aldehyde and monoterpene fractions dominated the chemical composition of essential oils.

Essential oil composition and anti Acanthamoeba studies of Teucrium ramosissimum

The aim of the present study was to evaluate the chemical composition of the essential oil obtained from the aerial parts of T. ramosissimum by hydrodistillation and to investigate their anti-Acanthamoeba activity. Identification and quantification were realized by gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection by (GC-FID).Sixty-eight compounds representing 97.78% of the essential oil were identified, of which δ-cadinene (18.63%), δ-cadinol (18.70%), β-eudesmol (12.13%), γ-gurjunene (4.34%) and 8-cedrene (3.99%) were the main compounds. This essential oil contained a complex mixture consisting mainly on sesquiterpenes (80.62%) and monoterpene fractions (14.34%). The findings of the anti-Acanthamoeba assay indicate that T. ramosissimum essential oil have a good activity with an IC50 = 25.73 ± 0.75 μg/mL.

Sulfate turpentine: a resource of tick repellent compounds

Compounds with tick (Ixodes ricinus) repellent properties were isolated from sulfate turpentine consisting of Norway spruce (80%) and Scots pine (20%) from southern Sweden. The turpentine was divided into two fractions by distillation under reduced pressure resulting in one monoterpene hydrocarbon fraction and a residual containing higher boiling terpenoids. The monoterpene fraction was further oxidized with SeO2 to obtain oxygenated monoterpenes with potential tick repellent properties. The oxidized fraction and the high boiling distillation residual were each separated by medium pressure liquid chromatography. The fractions were tested for tick repellency and the compounds in those with highest tick repellency were identified by GC-MS. The fractions with highest repellency contained, mainly (−)-borneol, and mixtures of (+)- and (−)-1-terpineol and terpinen-4-ol. The enantiomers of borneol showed similar tick repellent properties.

Screening of yarrow (Achillea millefolium Agg.) populations in Serbia for yield components and essential oil composition

Yarrow ( Achillea millefolium Agg.) is well-known medicinal plant, with a wide spectrum of applications and it is one of the most frequently used plant drug in Serbia. In this study, we have observed cultivation and essential oil chemical properties of 28 A. millefolium populations collected from Serbian sites. In the second vegetation, the yield of useful part (upper 15 cm) ranged from 925 – 3630 kg/ha, while the yield of essential oil ranged from 0.40 – 0.82%. %. The most dominant compounds in monoterpene fraction were b-pinene (max. 36.3%), sabinene (max. 35.7%), 1,8-cineol (max. 26.6%) and borneol (max. 20.2%), while in the sesquiterpene fraction the most abundant compounds were trans -caryophyllene (max. 18.6%) and lavandulyl acetate (max. 18.1%). Among aromatic compounds, the most abundant was chamazulene (max. 29.1%). This screening has shown that only 10 populations out of 28 satisfied official quality requirement of 0.02% of chamazulene in the dried drug. Four populations had higher yield than commercial variety ProA, while one of them had even higher level of chamazulene.

Volatile Constituents of the Leaf Oil of Cratoxylum cochinchinense from Vietnam

The genus Cratoxylum comprises over six species and is distributed in tropical areas and both hemispheres. Cratoxylum cochinchinense (Lour.) Blume (Syn: Hypericum cochinchinense Lour. (local name: Thanh Nganh) is a species of flowering plants in the Hypericaceae family. It is found in Brunei, China, India, Indonesia, Malaysia, Myanmar, the Philippines, Singapore, Thailand, and Vietnam. C. cochinchinense is a tree or bush-like herb often growing to heights of 1.6 m [1]. The resin of this herb has been used to treat dental problems. Its young leaves can be used against flu and dysentery, while the bark has been used to treat pruritis and colic. The leaves and roots of C. cochinchinense have been used in the treatment of stomachache and a decoction of the leaves and bark can be used to treat skin disorder. The young fruit is used as a spice for cooking. The root, bark, and twigs are used as a medicine for colds and diarrhea. The young leaves are used as a substitute for tea [2]. Several triterpenoids [3–5], xanthones [3–12], and phenolic compounds [13] have been isolated from this species in particular and the genus in general. Some of these compounds have been reported to possess significant pharmacological properties, including antioxidant [8], cytotoxic [9, 11, 13], antimalarial [9, 13], antibacterial [10, 12], and anti-HIV activities [14]. Leaves of C. cochinchinense (DND 2009) collected in Pu Mat National Park, Nghean Province, Vietnam, in December 2006, were used for this study. The air-dried sample (350 g) was hydrodistilled in a Clevenger-type apparatus [15] for 3 h. Oil yield was 0.20% (v/w) on a dry weight basis. About 15 mg of each oil sample, which was dried with anhydrous sodium sulfate, was dissolved in 1 mL of hexane (for spectroscopy or chromatography). GC analysis was performed on an Agilent Technologies HP 6890 Plus Gas chromatograph equipped with a FID and fitted with HP-Wax and HP-5MS columns (both 30 m 0.25 mm, film thickness 0.25 m, Agilent Technology). The analytical conditions were: carrier gas H 2 (10 mL·min –1 ), injector temperature (PTV) 250C, detector temperature 260C, column temperature programmed from 60C (2 min hold) to 220C (10 min hold) at 4C min –1 , split ratio 10:1, volume injected 1.0 L. An Agilent Technologies HP 6890N Plus chromatograph fitted with a fused silica capillary HP-5 MS column and interfaced with an HP5973 mass selective detector (5973 MSD) (70 eV) was used for the GC/MS analysis under the same conditions as above. Compound identification was performed by comparison of retention indices (RI) and MS data with literature data [16, 17]. Sixty-seven compounds were identified after GC/MS analysis, representing 92.4% of the total oil content (Table 1). The results also showed that the studied sample contained a high percentage of sesquiterpene hydrocarbons (60.2%) and the oxygenated counterpart (11.0%), which might have contributed to the characteristic odor of this oil. The major compounds among the sesquiterpenes were found to be -caryophyllene (16.0%) and bicyclogermacrene (18.4%). Other significant members of the class were germacrene D (4.6%), germacrene B (3.2%), and globulol (3.5%). The content of the monoterpene fraction was 20.2%, consisting largely of monoterpene hydrocarbons (19.1%). The main monoterpene hydrocarbons were sabinene (2.5%), -myrcene (7.1%), and (E)--ocimene (2.4%). We previously published our research findings on essential oils from Vietnam [18].