Comparative analysis of volatiles from Drimys brasiliensis Miers and D. angustifolia Miers (Winteraceae) from Southern Brazil

The essential oils obtained from Southern Brazilian native Drimys brasiliensis Miers and Drimys angustifolia Miers were analyzed by GC and GC/MS. The oils from leaves of both species showed predominance of monoterpenoids, while the oils from stem barks were characterized by sesquiterpenoids. Bicyclogermacrene (20.0% in leaves and 25.4% in stem bark) and drimenol (1.4% in leaves and 26.2% in stem bark) were the most abundant in D. angustifolia, and cyclocolorenone (from 16.0% to 32.3% in fresh and dried leaves and almost 50% in stem bark) in D. brasiliensis. The oil from fruits of D. brasiliensis was also analyzed and presented 31.0% of cyclocolorenone. The predominance of this unusual aromadendrane-type sesquiterpene in D. brasiliensis essential oils could be used as a chemosystematic marker.     

Essential oils composition of Eupatorium species growing wild in the Amazon

The essential oils of six Eupatorium species were obtained by hydrodistillation and analysed by GC-MS. The oil of E. macrophyllum was rich in sabinene (46.7%) and limonene (23.3%). The oil of E. laevigatum was mainly constituted by a mixture of aristolone+laevigatin (23.6%), globulol (16.2%) and germacrene D (8.6%). The principal constituents of the oils of the chemotypes A and B of E. squalidum, E. amygdalinum and E. conyzoides were caryophyllene oxide (17.4–30.1%), globulol (25.1%), germacrene D (10.4–21.6%), spathulenol (14.2%) and β-caryophyllene (7.1–12.3%). The oils of the chemotypes A and B of E. marginatum were dominated by α-zingiberene (57.5%), α-gurjunene (19.5%), germacrene D (14.8%), (E)-8-bisabolene (9.7%) and α-selinene (9.0%).     

Essential oil composition of nine Apiaceae species from western United States that attract the female Indra Swallowtail butterfly (Papilio indra)

Aletes acaulis, Cymopterus hendersonii, Cymopterus panamintensis var. acutifolius, Lomatium rigidum, Lomatium scabrum var. tripinnatum, Musineon tenuifolium, Sphenosciadium capitellatum, Tauschia arguta and Tauschia parishii are among the twenty-two species of the Apiaceae family to which female Indra Swallowtail butterflies (Papilio indra: Lepidoptera) are attracted for oviposition. Because plant volatile oils are known to be attractants for female butterflies, the percent composition of the essential oils of each species was studied. Amongst the nine host plants 168 essential oil components were identified representing between 84% and 99% of the oils. Principal Components Analysis and hierarchical cluster analysis on the essential oil compositions of the larval host plants against four non-larval host plants separated the hosts from the non-hosts into distinct clusters. Volatile components of the oils common to the nine species of Apiaceae are correlated with the expression of physiological attraction behavior by the butterfly.     

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

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

New species and a new combination in Myrtaceae from northeastern South America

Three new species of Myrtaceae (Calyptranthes bracteata, Eugenia gonglycocarpa, andMyrcia rupta) from northeastern South America are described and illustrated, and a new combination (Eugenia tetramera) is proposed. The closed-calyx and the completely or partially fused cotyledons ofMyrcia rupta, unusual features for the genus, are discussed and compared with related species inMyrcia andMarlierea.     

Chemical Composition and Biological Activities of the Essential Oil from Leaves and Flowers of Pulicaria incisa sub. candolleana (Family Asteraceae)

The composition of the essential oil isolated from leaves and flowers of Pulicaria incisa sub. candolleana E. Gamal ‐Eldin , growing in Egypt, was analysed by GC and GC‐MS. Forty‐nine and 68 compounds were identified from the oils of the leaves and flowers accounting for 86.69 and 84.29%, respectively of the total detected constituents. Both leaves and flowers oils were characterized by the high content of carvotanacetone with 66.01, 50.87 and chrysanthenone 13.26, 24.3%, respectively. The cytotoxic activity of both essential oils was evaluated against hepatocellular carcinoma cell line HEPG‐2, using MTT assay and vinblastine as a reference drug. Leaf oil showed higher activity with IC₅₀ 11.4 μg/ml compared with 37.4 μg/ml for flower oil. The antimicrobial activity of both oils was evaluated using agar well diffusion method towards two representatives for each of Gram positive and Gram negative bacteria as well as four representatives for fungi. The minimum inhibitory concentration of both essential oils against bacterial and fungal strains was obtained in the range of 0.49 – 15.63 μg/ml.     

Determination of the Phytochemical Composition and Antioxidant Potential of Eugenia copacabanensis and Myrciaria tenella Leaves (Myrtaceae) Using a Saccharomyces cerevisiae Model

Eugenia copacabanensis and Myrciaria tenella are present in restingas of the Atlantic Forest, but little information is available about their chemical and biological potential. In this context, the hexane, dichloromethane, ethyl acetate and butanol fractions from the leaves of methanolic extract were analyzed by GC/MS and HPLC-DAD and the antioxidant potential was determined by DPPH and ABTS assays and using a Saccharomyces cerevisiae model. Dereplication allowed the identification of 68 compounds, 42 and 41 of which, respectively, are first reported here for E. copacabanensis and M. tenella. In vivo results revealed that the ethyl acetate and butanol fractions showed expressive antioxidant protection in the BY4741 and Δgsh1 strains, with greater impact on glutathione-deficient cells. With a high diversity of phenolic compounds, these polar fractions of E. copacabanensis and M. tenella leaves are potential protectors against intracellular oxidative stress.     

Chemical composition and antibacterial activities of seven Eucalyptus species essential oils leaves

Background

In this paper, we have studied the essential oils chemical composition of the leaves of seven Eucalyptus species developed in Tunisia. Eucalyptus leaves were picked from trees growing in different arboretums in Tunisia. Choucha and Mrifeg arboretums located in Sedjnene, region of Bizerte (Choucha: E. maideni, E. astrengens et E. cinerea; Mrifeg : E. leucoxylon), Korbous arboretums located in the region of Nabeul, North East Tunisia with sub-humid bioclimate, (E. lehmani), Souiniet-Ain Drahem arboretum located in region of Jendouba (E. sideroxylon, E. bicostata). Essential oils were individually tested against a large panel of microorganisms including Staphylococcus aureus (ATCC 6539), Escherichia coli (ATCC 25922), Enterococcus faecalis (ATCC29212), Listeria ivanovii (RBL 30), Bacillus cereus (ATCC11778).

Results

The yield of essential oils ranged from 1.2% to 3% (w/w) for the different Eucalyptus species. All essential oils contain α-pinene, 1,8-cineol and pinocarveol-trans for all Eucalyptus species studied. The 1,8-cineol was the major compound in all species (49.07 to 83.59%). Diameter of inhibition zone of essential oils of Eucalyptus species varied from 10 to 29 mm. The largest zone of inhibition was obtained for Bacillus cereus (E. astrengens) and the lowest for Staphylococcus aureus (E. cinerea). The essential oils from E. maideni, E. astrengens, E. cinerea (arboretum of Bizerte), E. bicostata (arboretum of Aindraham) showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus.

Conclusion

The major constituents of Eucalyptus leaves essential oils are 1,8-cineol (49.07 to 83.59%) and α-pinene (1.27 to 26.35%). The essential oils from E. maideni, E. astrengens, E. cinerea, E. bicostata showed the highest antibacterial activity against Listeria ivanovii and Bacillus cereus, they may have potential applications in food and pharmaceutical products.     

Chemical detoxification vs mechanical removal of host plant toxins in Eucalyptus feeding sawfly larvae (Hymenoptera: Pergidae)

The essential oils that characterize the eucalypts and related Myrtaceae pose a challenge for herbivores. Phytophagous insects that feed on oil-rich Myrtaceae have developed specific mechanisms to deal with these oils, some of which are notoriously toxic (e.g. 1,8-cineole). Some of the eight Australian subfamilies in the sawfly family Pergidae are associated exclusively with Eucalyptus and Melaleuca species that often have high concentrations of essential oils. Unexpectedly, the Perginae and Pterygophorinae use different mechanisms to deal with the same toxic components in their respective host plants. Larvae of the Perginae have the inner surface of their mandibles equipped with soft brush-like structures that are unique among phytophagous insects in general. The proposed role of these ancillary mandibular structures in separating leaf oils from nutritive plant matter could be confirmed in experiments with larvae of two pergine species. The oil sequestration is, however, incomplete and chemical gut content analyses by gas-chromatography (GC) revealed that 1,8-cineole does enter the midgut and is metabolised to hydroxycineole. Although the related Pterygophorinae also feed mainly on oil-rich Myrtaceae, they do not sequester the oil and lack morphological structures on their mandibles. Chemical analysis of the gut content of two pterygophorine species showed that they rely solely on chemical detoxification of the relevant plant compounds, with GC demonstrating that the 1,8-cineole is removed far more rapidly and completely than in the pergine species.     

Essential oil composition of Hypericum L. species from Southeastern Serbia and their chemotaxonomy

The essential oils of the aerial parts of nine species of Hypericum (Hypericum barbatum, Hypericum hirsutum, Hypericum linarioides, Hypericum maculatum, Hypericum olympicum, Hypericum perforatum, Hypericum richeri, Hypericum rumeliacum and Hypericum tetrapterum), collected from different locations in Southeast Serbia, were obtained by steam distillation and analyzed by GC and GC–MS. The essential oils investigated were characterized by a high content of non-terpene compounds and a low content of monoterpenes. The contents of non-terpenes, monoterpenes and sesquiterpenes in oils of the species H. barbatum, H. richeri and H. rumeliacum (section Drosocaprium) were similar and these oils were characterized by high contents of fatty acids. The oils of H. hirsutum and H. linarioides (section Taeniocarpium) contained a high percentage of n-nonane. There were similarities in contents of non-terpenes and sesquiterpenes in oils of species that belong to the section Hypericum (H. maculatum, H. perforatum and H. tetrapterum). The oil of H. olympicum differed from others by higher terpene content. A comparison was also carried out of the chemical composition of the essential oils from flower, leaf and stem of H. perforatum and it revealed that the highest concentration of non-terpene compounds was found in the flower and stem oil, while a high concentration of sesquiterpenes was characteristic for leaf oil. There were significant differences in the concentrations of the same compounds in the essential oils of H. maculatum, H. olympicum and H. perforatum, collected in different years from the same location which could be explained by seasonal differences. All data were statistically processed with principal component analysis and cluster analysis. The main conclusion from the above data is that genetic and environmental factors both play a role in determining the composition of essential oils of the Hypericum species studied.     

Compositional studies and Biological activities of Perovskia abrotanoides Kar. oils

Background

Current study has been designed to evaluate the chemical composition of essential and fixed oils from stem and leaves of Perovskia abrotanoides and antioxidant and antimicrobial activities of these oils.

Results

GC-MS analysis of essential oil identified 19 compounds with (E)-9-dodecenal being the major component in stem and hexadecanoic acid in leaves. In contrast, GC-MS analysis of fixed oil showed 40 constituents with α-amyrin the major component in stem and α-copaene in leaves. The antioxidant activity showed the highest value of 76.7% in essential oil from leaves in comparison with fixed oil from stem (45.9%) through inhibition of peroxidation in linoleic acid system. The antimicrobial assay tested on different microorganisms (e.g. E. coli, S. aureus, B. cereus, Nitrospira, S. epidermis, A. niger, A. flavus and C. albicans) showed the higher inhibition zone at essential oil from leaves (15.2 mm on B. cereus) as compared to fixed oil from stem (8.34 mm on S. aureus) and leaves (11.2 mm on S. aureus).

Conclusions

The present study revealed the fact that essential oil analyzed from Perovskia abrotanoides stem and leaves could be a promising source of natural products with potential antioxidant and antimicrobial activities, as compared to fixed oil.     

Chemical composition and antimicrobial activity of Cymbopogon citratus and Cymbopogon giganteus essential oils alone and in combination

As part of ongoing research on the chemical composition and the antimicrobial properties of Burkinabe plants essential oils alone and in combination, essential oils (EOs) from leaves of Cymbopogon citratus and Cymbopogon giganteus from Burkina Faso were analyzed by GC-FID and GC-MS. Five constituents, which accounted for 96.3% of the oil, were identified in the EO of C. citratus. Geranial (48.1%), neral (34.6%) and myrcene (11.0%) were the major constituents. For C. giganteus a total of eight compounds were identified which represented 86.0% of the oils extracted. The dominant compounds were limonene (42%) and a set of monoterpene alcohols: trans-p-mentha-1(7),8-dien-2-ol (14.2%), cis-p-mentha-1(7),8-dien-2-ol (12%), trans-p-mentha-2,8-dien-1-ol (5.6%) and cis-p-mentha-2,8-dien-1-ol (5.2%). The EOs were tested against nine bacteria by using disc diffusion and microdilution methods. C. giganteus EO showed antimicrobial effects against all microorganisms tested whereas C. citratus EO failed to inhibit Pseudomonas aeruginosa. The antimicrobial activity of combinations of the two EOs was quantified by the checkerboard method. Combinations of the two EOs exerted synergistic, additive and indifferent antimicrobial effects. Results of the present investigation provide evidence that the combinations of plant EOs could be assessed for synergistic activity in order to reduce their minimum effective dose.     

黄花蒿与其近缘种化学成分的FTIR和GC-MS鉴定与分析

黄花蒿是一种治疗痢疾的特效中药,植物体中含有丰富的精油,但其应用和生产中常有种类混杂现象,严重影响了黄花蒿为原料的药材质量。为实现黄花蒿药材快速鉴定与评价,该研究利用FTIR技术和GCMS分别对黄花蒿及其近缘种叶片原药材及挥发油成分进行了检测和鉴定。结果表明:挥发油以黄花蒿含量最高(1.86%),其次是南牡蒿、茵陈蒿、青蒿、牡蒿和艾蒿。FTIR分析结果表明,黄花蒿及其近缘种一维图谱相似,酰胺类、芳香类以及萜类化合物种类较多且含量丰富;二阶导数图谱中,黄花蒿青蒿素成分振动吸收明显增强,可以明显将黄花蒿与其混淆中区分开。GC-MS分析显示,黄花蒿与其近缘种的挥发油成分中共检测出17个共有峰,28种化学成分,均含有较高樟脑、á-杜松烯、Crocetane、植烷、2,4-二叔丁基苯酚,但不同种间成分含量差异很大,植烷在黄花蒿中含量明显高于其它近缘种,龙脑成分只能在黄花蒿叶片中检测出,然而á-雪松烯在青蒿、南牡蒿、茵陈蒿均较高,而在黄花蒿,艾蒿,牡蒿中含量均较低。最后通过聚类分析探讨了黄花蒿与其近缘种挥发油成分差异性,6种材料明显聚为2类。其中,黄花蒿与牡蒿、艾蒿聚为一类,青蒿与茵陈蒿和南牡蒿聚为一类。该研究结果为黄花蒿药材的真伪鉴别及其药材质量评价提供了快速而有效的分析手段。     

The ecological significance of the coarse soil fraction for Picea abies (L.) Karst. seedling nutrition

Elsholtzia splendens is a Cu-tolerant plant growing in copper mine areas in the south of China. In this study, X-ray absorption spectroscopy (XAS) was used to investigate the Cu speciation and biotransformation in E. splendens with 300 μM Cu treatment from 10 days to 60 days. The results showed that 300 μM Cu was phytotoxic to E. spendens. The Cu K-edge X-ray absorption near edge structure (XANES) revealed that most copper in roots, stems and leaves exists as divalent Cu. Cu speciation changed depending on the treatment time, but there was no unidirectional trend in roots, stems, and leaves. The percentages of potential Cu ligands in all samples were estimated by fitting the XANES spectra with linear combinations. Most Cu in roots, stems and leaves was bound with cell wall and histidine (His)-like ligands, while a minor proportion of the Cu was bound to oxalate and glutathione-like ligands. The fitting results of Cu K-edge extended X-ray absorption fine structure (EAXFS) showed that nitrogen/oxygen (N/O) ligands were dominant in roots, stems and leaves of the plant, while S ligands were rare. All these results suggest that Cu bound by N/O ligands plays a key role in Cu detoxification of E. splendens, and a role for classical metal-detoxifying S ligands, such as metallothioneins and phytochelatins, in Cu detoxification of E. splendens is not supported in the present study. Due to the phytotoxicity of 300 μM Cu to E. splendens, the question of whether S ligands play a significant role in Cu detoxification in E. splendens exposed to lower levels of Cu should be further studied.     

Chemotaxonomy of Hypericum genus from Portugal: Geographical distribution and essential oils composition of Hypericum perfoliatum, Hypericum humifusum, Hypericum linarifolium and Hypericum pulchrum

The geographical distribution and analysis of the essential oils of species from three sections of Hypericum L. (Guttiferae/Clusiaceae/Hypericaceae) from Portugal are presented. Hypericum perfoliatum (section Drosocarpium) grows wild in the centre and south of Portugal; Hypericum humifusum and Hypericum linarifolium are both from section Oligostema, the former occurring throughout the country, while the second is distributed mainly in the north and centre; Hypericum pulchrum (section Taeniocarpium) is confined to the littoral north of Portugal. The essential oils were obtained by distillation–extraction, hydrodistillation and distillation in a modified Marcusson apparatus from the dried aerial parts of the different populations and were analysed by GC and GC–MS. Monoterpene hydrocarbons constituted the main fraction in all oils (43–69%, 53–85%, 28–45% and 48–65% for H. perfoliatum, H. humifusum, H. linarifolium and H. pulchrum, respectively). Sesquiterpene hydrocarbons (2–13%, 6–18%, 21–27% and 16–18%, respectively) and a third fraction of non-terpenic compounds (20–29%, 3–16%, 2–14% and 5–11%, respectively) from the four species attained relatively high amounts in all oils. Within each species, no major differences were detected in the essential oil composition, despite the fact that different locations, phenological phases and extraction methodologies were used. Notwithstanding the dominance of α-pinene in all four species' oils, cluster and principal components analysis on the identified components showed that the range of α-pinene, β-pinene and n-nonane supported a separation of the four species. The essential oil composition of the four species showed some qualitative resemblances, which correlate well with the taxonomical classification based on morphological characters.     

<Emphasis Type="Italic">Marcetia candolleana</Emphasis> (<Emphasis Type="Italic">Melastomeae</Emphasis> – <Emphasis Type="Italic">Melastomataceae</Emphasis>), a new species from Bahia (Brazil)

Summary   Marcetia candolleana A. K. A. Santos & A. B. Martins, is apparently restricted to Mucugê, Bahia (Brazil), where it occurs in areas of campo rupestre vegetation. This new species is closely related to the sympatric M. mucugensis Wurdack, but can be easily recognised by its semi-prostate to procumbent habit, reddish glandular-hirsute indument, loose and flexuous branches, leaves with inconspicuous reticulation on the abaxial surface, connectives very shortly prolonged below the thecae, style curved towards the apex, not exceeding the anthers, and pendulous fruit.

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Resumo   Marcetia candolleana A. K. A. Santos & A. B. Martins, é aparentemente restrita a Mucugê, Bahia (Brasil), onde ocorre em áreas de campo rupestre. Esta nova espécie é proximamente relacionada à M. mucugensis Wurdack, mas pode ser facilmente reconhecida por seu hábito semi-prostado a procumbente, indumento glandular-hirsuto, vináceo, ramos flexuosos, folhas inconspicuamente reticuladas na face abaxial, conectivos muito curtamente prolongados abaixo das tecas, estilete curvo no ápice, n?o ultrapassando o comprimento das anteras, e fruto pêndulo.

     

Essential oil composition of Eryngium rosulatum P.W. Michael ined.: A new undescribed species from eastern Australia

The essential oil composition from the aerial parts of a new Eryngium species from Australia, Eryngium rosulatum P.W. Michael ined., has been analysed by GC and GC/MS. A total of 34 compounds have been identified representing around 80% of the total oil. The main constituents of the oil were found to be β-elemene (16.0%) and bicyclogermacrene (12.5%). Other representative compounds were identified as δ-elemene (7.0%) and (E)-caryophyllene (5.9%). The sesquiterpene fraction (75.0%) was predominant in the essential oil of this species, most of these were hydrocarbons (53.8%). This paper represents the first study on this new, undescribed Australian species and its chemical composition.     

Biochemical activities of Iranian Mentha piperita L. and Myrtus communis L. essential oils

GC-MS analysis of essential oils of Iranian Mentha piperita and Myrtus communis extracted by hydrodistillation lead to identification of 26 and 32 compounds, respectively. The oils had good to excellent antimicrobial activities against Escherichia coli, Staphylococcus aureus and Candida albicans with the oil of M. piperita being more active. The findings suggest feasibility of application of M. piperita oil in treatment of the infections caused by C. albicans and E. coli. D-values on exposure to M. piperita and Myrtus communis oils were (2.14 and 2.8min), (1.4 and 12.8min) and (4.3 and 8.6min) for E. coli, S. aureus and C. albicans , respectively. The oils were screened for their possible antioxidant activities by two complementary test systems, namely DPPH free radical scavenging and beta-carotene/linoleic acid systems. M. piperirta oil exerted greater antioxidant activity than that of M. communis. Phytochemical and phytobiological characteristics of these oils may lead to extraction and production of active compounds in single or combined forms with useful applications.     

Changes in composition of essential oils and volatile emissions of Minthostachys mollis, induced by leaf punctures of Liriomyza huidobrensis

Plant defensive mechanisms against herbivores include chemical changes following damage. Effects of feeding punctures produced by Liriomyza huidobrensis (pea leafminers) adult females on the plant's dominant monoterpenes, pulegone and menthone were assessed by monitoring essential oil composition at 24, 48, and 120 h; emission of volatiles was also measured 24 and 48 h after wounding. We studied such changes in Minthostachys mollis, a Lamiaceae species native to Central Argentina with medicinal and aromatic uses. Leaf puncturing resulted in reduced menthone throughout the experiment and increased pulegone concentration in M. mollis essential oil during the first 48 h. The adjacent undamaged leaves showed similar changes, suggesting a systemic response. Composition of volatiles released from damaged leaves was also altered, most noticeably by increasing pulegone and diminishing menthone emissions. Such herbivore-induced chemical changes in aromatic plants are economically relevant, since the quality of essential oils and volatile emissions are altered.