WorldWideScience

Sample records for brominated selinane sesquiterpenes

  1. Bromine Safety

    Energy Technology Data Exchange (ETDEWEB)

    Meyers, B

    2001-04-09

    The production and handling in 1999 of about 200 million kilograms of bromine plus substantial derivatives thereof by Great Lakes Chemical Corp. and Albemarle Corporation in their southern Arkansas refineries gave OSHA Occupational Injury/Illness Rates (OIIR) in the range of 0.74 to 1.60 reportable OIIRs per 200,000 man hours. OIIRs for similar industries and a wide selection of other U.S. industries range from 1.6 to 23.9 in the most recent OSHA report. Occupational fatalities for the two companies in 1999 were zero compared to a range in the U.S.of zero for all computer manufacturing to 0.0445 percent for all of agriculture, forestry and fishing in the most recent OSHA report. These results show that bromine and its compounds can be considered as safe chemicals as a result of the bromine safety standards and practices at the two companies. The use of hydrobromic acid as an electrical energy storage medium in reversible PEM fuel cells is discussed. A study in 1979 of 20 megawatt halogen working fluid power plants by Oronzio de Nora Group found such energy to cost 2 to 2.5 times the prevailing base rate at that time. New conditions may reduce this relative cost. The energy storage aspect allows energy delivery at maximum demand times where the energy commands premium rates. The study also found marginal cost and performance advantages for hydrobromic acid over hydrochloric acid working fluid. Separate studies in the late 70s by General Electric also showed marginal performance advantages for hydrobromic acid.

  2. Bromination of Phenol

    Science.gov (United States)

    Talbot, Christopher

    2013-01-01

    This "Science note" examines the bromination of phenol, a reaction that is commonly taught at A-level and IB (International Baccalaureate) as an example of electrophilic substitution. Phenol undergoes bromination with bromine or bromine water at room temperature. A white precipitate of 2,4,6-tribromophenol is rapidly formed. This…

  3. Sesquiterpene coumarins from Ferula gumosa.

    Science.gov (United States)

    Iranshahi, Mehrdad; Masullo, Milena; Asili, Ali; Hamedzadeh, Ali; Jahanbin, Bentolhoda; Festa, Michela; Capasso, Anna; Piacente, Sonia

    2010-11-29

    A new sesquiterpene coumarin, gumosin (1), two new sesquiterpene coumarin glycosides, gumosides A (2) and B (3), and 10 known compounds, namely, cauferoside (4), feselol (5), conferoside, ferilin, ferocaulidin, ligupersin A, conferol, and daucosterol, and the phenolic compounds acantrifoside E and 4-hydroxybenzoic acid 4-(6-O-sulfo)glucopyranoside, were isolated from a methanolic extract of Ferula gumosa roots. The structures of 1-3 were elucidated by spectroscopic data interpretation. The cytotoxic activity of the sesquiterpene coumarin derivatives was evaluated against a small panel of cancer cell lines.

  4. Sesquiterpenes from Carpesium longifolium

    Institute of Scientific and Technical Information of China (English)

    YANG Chao; YUAN Cheng-Shan; JIA Zhong-Jian

    2003-01-01

    @@ The genus Carpesium (Compositae) with only 21 species is widely distributed in Asia, mainly in the southwest ern mountainous regions of China. The seeds, roots, leaves and stems of some Carpesium species have long been used as Chinese traditional medicine for hemostatic, vermifuge, anti-inflammatory and detoxication properties. [1,2]Here, we report the first phytochemical investigation of Carpesium longifolium Chen et C. M. Hu, which led to the isolation and structural elucidation of four new sesquiterpene lactones 1 ~ 4 and five known compounds 5 ~ 9, the cy totoxic activity test of three compounds 5, 6 and 7, and compounds 5 and 7 exhibited significant cytotoxic activity against cultured SMMC-7721 (human hepatoma cell) and HO-8910 (human ovarian carcinoma cell).

  5. Sesquiterpenes from Cupressus macrocarpa foliage.

    Science.gov (United States)

    Cool, Laurence G

    2005-01-01

    Ten sesquiterpenes, many with unusual carbon skeletons, were identified in foliage of Cupressus macrocarpa. These are (-)-10-epi-beta-acoradiene; ent-widdra-2,4(14)-diene; (E)-iso-gamma-bisabolene, i.e., (4E)-4-(1,5-dimethylhex-5-enylidene)-1-methylcyclohexene; (-)-cumacrene, i.e., (4S)-4-[(1R,2S)-2-isopropenyl-1-methylcyclobutyl]-1-methylcyclohexene; (-)-alpha-chamipinene, i.e., (1S,6S,7S)-2,2,6,8-tetramethyltricyclo[5.3.1.01,6]undec-8-ene; and five sesquiterpenes with a 3,3,4'-trimethyl-1,1'-bi(cyclohexyl) skeleton for which the trivial name macrocarpane is proposed. The possible single-enzyme biogenesis of these sesquiterpenes is discussed.

  6. Sesquiterpene Lactones from Notoseris Porphyrolepis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Two new sesquiterpene lactones, notoserolides A and B, along with 12 known compounds were isolated from the aerial parts of Notoseris porphyrolepis.By means of spectral methods including MS, NMR (1H NMR, 13C NMR, DEPT, HMQC, HMBC) and X-ray diffraction, as well as chemical reactions, the structures of notoserolides A and B were established as austricin 8-O-β-D-glucopyranoside and 8-O-senecioylaustricin, respectively.

  7. Sesquiterpene compounds from Inula viscosa.

    Science.gov (United States)

    Fontana, Gianfranco; La Rocca, Salvatore; Passannanti, Salvatore; Paternostro, Maria Pia

    2007-07-20

    Two new compounds, 2,5-dihydroxyisocostic acid and 2,3-dihydroxycostic acid together with three known sesquiterpene compounds, Isocostic acid, Carabrone and Tomentosin, have been isolated from the acetone extract of Inula viscosa (L.) Aiton. The structures of all new compounds were determined by spectroscopic methods, in particular 1D and 2D (1)H- and (13)C-NMR. The (13)C-NMR spectra of Isocostic acid and of Tomentosin are reported here for the first time.

  8. Sesquiterpene coumarins from seeds of Ferula sinkiangensis.

    Science.gov (United States)

    Li, Guangzhi; Li, Xiaojin; Cao, Li; Zhang, Lijing; Shen, Liangang; Zhu, Jun; Wang, Junchi; Si, Jianyong

    2015-06-01

    A new sesquiterpene coumarin with a novel sesquiterpene carbon framework, Sinkiangenorin D, and ten known sesquiterpene coumarins were isolated from the seeds of Ferula sinkiangensis. The structures of these compounds, including the relative stereochemistry, were elucidated on the basis of spectroscopic data. All of the isolated compounds were tested against the AGS, HeLa, and K562 human cancer cell lines and showed cytotoxic activities with 50% inhibitory concentration values between 12.7 and 226.6 μM.

  9. Sesquiterpenes from the Formosan stolonifer Tubipora musica.

    Science.gov (United States)

    Duh, C Y; Chen, K J; El-Gamal, A A; Dai, C F

    2001-11-01

    Eight new sesquiterpenes, tubipolides A-G (1-7) and tubiporone (8) (novel carbon skeleton), and a known sesquiterpene, spirotubipolide, have been isolated from the Formosan stolonifer Tubipora musica. The structures of compounds 1-8 were determined by 1D and 2D NMR spectral analysis.

  10. Biologically active sesquiterpene coumarins from Ferula species.

    Science.gov (United States)

    Nazari, Zeinab Esmail; Iranshahi, Mehrdad

    2011-03-01

    Extracts from different species of the genus Ferula (Apiaceae) have had various biomedical applications for many centuries. Many biological features of this genus such as cytotoxicity, antibacterial, antiviral, P-glycoprotein (P-gp) inhibitory and antiinflammatory activity have been attributed to sesquiterpene coumarins; structures containing a common coumarin group and a sesquiterpene moiety. This both highlights the importance of sesquiterpene coumarins as biologically active natural products and necessitates further studies on these compounds. Taking into account the versatile biological properties of compounds isolated from Ferula and the unprecedented interest in the application of natural products as a new generation of therapeutics, the present review will discuss reports on biological activities of sesquiterpene coumarins of the genus Ferula, from 1990 onwards.

  11. Allergenic sesquiterpene lactones from cushion bush (Leucophyta brownii Cass.)

    DEFF Research Database (Denmark)

    Paulsen, Evy; Gade Hyldgaard, Mette; Andersen, Klaus E.

    2017-01-01

    BACKGROUND: The Australian cushion bush (Leucophyta brownii) of the Compositae family of plants has become a popular pot and container plant. The plant produces the sesquiterpene lactone allergen calocephalin. OBJECTIVES: To assess the sensitizing potential of sesquiterpene lactones from cushion ...

  12. New Eremophilane Sesquiterpenes from Cacalia ainsliaeflora

    Institute of Scientific and Technical Information of China (English)

    Mao Man-Jun; YANG Xiu-Ping; JIA Zhong-Jian

    2003-01-01

    @@ Cacalia ainsliaeflora, a compositae distributed in the west of China, has long been used as Chinese traditional medicine for invigorating the circulation of blood, curing pellagra, rheumatismal edema and as an insecticide. [1] We recently reported the isolation and identification of five eremophilane sesquiterpenes from this plant. [2] In our continuing research on the bioactive constituents from Cacalia species, we reinvestigated the chemical constituents of the roots of C. ainsliaeflora. As a result, seven new eremophilane sesquiterpenes (2 ~ 8), and a known erempphilanolide (1) were isolated. Their structures were elucidated by spectroscopic methods.

  13. Zinc-bromine battery development

    Science.gov (United States)

    Richards, Lew; Vanschalwijk, Walter; Albert, George; Tarjanyi, Mike; Leo, Anthony; Lott, Stephen

    1990-05-01

    This report describes development activities on the zinc-bromine battery system conducted by Energy Research Corporation (ERC). The project was a cost-shared program supported by the U.S. Department of Energy and managed through Sandia. The project began in September 1985 and ran through January 1990. The zinc-bromine battery has been identified as a promising alternative to conventional energy storage options for many applications. The low cost of the battery reactants and the potential for long life make the system an attractive candidate for bulk energy storage applications, such as utility load leveling. The battery stores energy by the electrolysis of an aqueous zinc bromide salt to zinc metal and dissolved bromine. Zinc is plated as a layer on the electrode surface while bromine is dissolved in the electrolyte and carried out of the stack. The bromine is then extracted from the electrolyte with an organic complexing agent in the positive electrolyte storage tank. On discharge the zinc and bromine are consumed, regenerating the zinc bromide salt.

  14. Total synthesis of insect antifeedant drimane sesquiterpenes.

    NARCIS (Netherlands)

    Jansen, B.J.M.

    1993-01-01

    The investigations described in this thesis deal with the total synthesis of sesquiterpenes of the drimane family, named for their widespread occurrence in the stem bark of South American Drimys species. These compounds contain the bicyclofarnesol nucleus 1 , which is invariably oxi

  15. Two new aristolane sesquiterpenes from Laurencia similis

    Institute of Scientific and Technical Information of China (English)

    Nai Yun Ji; Xiao Ming Li; Lan Ping Ding; Bin Gui Wang

    2007-01-01

    Two new aristolane sesquiterpenes, namely, aristolan-10-ol-9-one and aristolan-8-en-1-one, were isolated from the red alga Laurencia similis. Their structures were established on the basis of various NMR spectroscopic analyses, including 2D NMR techniques (1H-1H COSY, HMQC, HMBC, and NOESY) and HR-FAB-MS.

  16. Sesquiterpenes from aerial parts of Ferula vesceritensis.

    Science.gov (United States)

    Oughlissi-Dehak, Karima; Lawton, Philippe; Michalet, Serge; Bayet, Christine; Darbour, Nicole; Hadj-Mahammed, Mahfoud; Badjah-Hadj-Ahmed, Yacine A; Dijoux-Franca, Marie-Geneviève; Guilet, David

    2008-06-01

    From the dichloromethane extract of aerial parts of Ferula vesceritensis (Apiaceae), 11 sesquiterpene derivatives were isolated. Among them five were compounds designated as 10-hydroxylancerodiol-6-anisate, 2,10-diacetyl-8-hydroxyferutriol-6-anisate, 10-hydroxylancerodiol-6-benzoate, vesceritenone and epoxy-vesceritenol. The six known compounds were identified as feselol, farnesiferol A, lapidol, 2-acetyl-jaeschkeanadiol-6-anisate, lasidiol-10-anisate and 10-oxo-jaesckeanadiol-6-anisate. All the structures were determined by extensive spectroscopic studies including 1D and 2D NMR experiments and mass spectroscopy analysis. Two of the compounds, the sesquiterpene coumarins farnesiferol A and feselol, bound to the model recombinant nucleotide-binding site of an MDR-like efflux pump from the enteropathogenic protozoan Cryptosporidium parvum.

  17. Antibacterial sesquiterpene aryl esters from Armillaria mellea.

    Science.gov (United States)

    Donnelly, D M; Abe, F; Coveney, D; Fukuda, N; O'Reilly, J; Polonsky, J; Prangé, T

    1985-01-01

    Investigation of the mycelial extract of Armillaria mellea led to the isolation of the known melleolide (2a) and two new sesquiterpene aryl eters, 4-O-methylmelleolide (2b) and judeol (1c). Their structures were deduced from spectral data and that of (2b) confirmed by X-ray analysis. The new esters (1c) and (2b) showed strong antibacterial activity against gram-positive bacteria.

  18. Guaiane sesquiterpene lactones from Salvia nubicola (Lamiaceae).

    Science.gov (United States)

    Ali, Muhammad S; Ibrahim, Syed A; Ahmed, Shakeel; Lobkovsky, Emil

    2007-01-01

    A new sesquiterpene lactone, nubiol (1), belonging to the guaiane class, along with a dimer, bisnubidiol (2), has been isolated from Salvia nubicola collected from Quetta, Pakistan. The structures of both metabolites were elucidated with the aid of spectroscopic techniques including 2D-NMR. Additionally, the structure of nubiol (1) was finally confirmed via the single crystal X-ray diffraction. Nubiol (1) was found moderately active against Pseudomonas aeruginosa.

  19. A new sesquiterpene from Caragana intermediia

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new alloaromadendrane-type sesquiterpene, (-)-alloaromadendrane-3β,9β-diol (1), has been isolated from the aerial part of Caragana intermediia. The structure of (-)-alloaromadendrane-3β,9β-diol (1) was established by spectroscopic methods,including X-ray analysis that provided its relative stereochemistry. Bioassay showed that (-)-alloaromadendrane-3β,9β-diol(1) possesses anti-pyricularia oryzae P-2b activity with MIC value of 10 μg/mL.

  20. A Novel Protoilludane Sesquiterpene from the Wood of Xanthoceras sorbifolia

    Institute of Scientific and Technical Information of China (English)

    Chao Mei MA; Norio NAKAMURA; As'ari NAWAWI; Masao HATTORI; Shao Qing CAI

    2004-01-01

    A protoilludane sesquiterpene (named xanthocerapene) was isolated from the wood of Xanthoceras sorbifolia Bunge. Its structure, including the relative configuration was established by spectroscopic and chemical methods.

  1. Production of bromine-75, a new radionuclide for marking radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Paans, A.M.J.; Wiegman, T.; Hoeve, W.; Vaalburg, W. (Rijksuniversiteit Groningen (Netherlands). Academisch Ziekenhuis)

    1982-01-01

    Bromine-75 is the most useful of all bromine isotopes for nuclear medicine. Its properties like half-life, nuclear reactions, production and chemical preparation, as well as the preparation of radiopharmaceuticals containing bromine-75 are presented.

  2. Sesquiterpene coumarin and sesquiterpene chromone derivatives from Ferula ferulaeoides (Steud.) Korov.

    Science.gov (United States)

    Meng, He; Li, Guoyu; Huang, Jian; Zhang, Ke; Wang, Hangyu; Wang, Jinhui

    2013-04-01

    Five novel compounds - three sesquiterpene coumarin derivatives, ferulin A (1), B (2), and C (3), and two sesquiterpene chromone derivatives, ferulin D (4) and E (5), together with eleven known compounds (6-16) have been isolated from the roots of Ferula ferulaeoides (Steud.) Korov. Their structures were established by comprehensive spectroscopic analysis. The biosynthetic pathways leading to these compounds were proposed. The cytotoxicity of all these isolates against HepG2, MCF-7, and C6 cancer cell lines was evaluated and compound 7 displayed the highest potency against HepG2, MCF-7, and C6 with IC50 values 39.9 μM, 37.7 μM, and 16.0 μM, respectively.

  3. Sesquiterpene lactones. XXXVI. Sesquiterpene lactones in several subgenera of the genus Centaurea L.

    OpenAIRE

    Gerard Nowak; Miroslaw Holub; Miloš Buděšĺnský

    2014-01-01

    The occurrence of both known and new sesquiterpene lactones was determined in six species classified in different subgenera of Centaurea L. Chlorojanerin, cynaropicrin and janerin were isolated from C. phaeopappoides Bordz. and C. thracica (Janka) Hayek. C. marschalliana Spreng. was found to contain acroptilin, chlorojanerin, cebellin D and janerin while C. adjarica Alb. had repin, acroptilin, chlorojanerin, centaurepensin, janerin, repidiolide, cebellin D, E, F and L A new, hitherto underscr...

  4. Thermodynamic properties of sesquiterpene lactone grossheimin

    Science.gov (United States)

    Kasenova, Sh. B.; Atazhanova, G. A.; Sagintaeva, Zh. I.; Kasenov, B. K.; Kishkentaeva, A. S.; Adekenov, S. M.

    2016-08-01

    The enthalpy of dissolution of sesquiterpene lactone grossheimin C15H18O4 is measured using a DAK-I-IA calorimeter at a lactone/ethanol (96%) molar ratios equal to 1 : 18000, 1 : 36000, and 1 : 72000. The standard enthalpy of dissolution of grossheimin in a 96% ethanol solution is calculated based on the resulting data. The temperature dependence of the heat capacity of grossheimin C p ° ˜ f ( T) is studied by means of dynamic calorimetry using a IT-C-400 device in the temperature range of 298.15-423 K. An equation describing this dependence is derived. The standard enthalpies of combustion, melting, and formation of grossheimin are calculated using approximate methods.

  5. Cynaratriol, a sesquiterpene lactone from Centaurea musimomum

    Directory of Open Access Journals (Sweden)

    Matías López-Rodríguez

    2009-08-01

    Full Text Available The title compound [systematic name: 3,8-dihydroxy-3-(hydroxymethyl-9-methyl-6-methylenedecahydroazuleno[4,5-b]furan-2(3H-one], C15H22O5, is a sesquiterpene lactone showing the typical tricyclic guaianolide skeleton which has been isolated, together with other related metabolites, from the plant Centaurea musimomum. The present study confirms the molecular structure, assigned by 1H NMR and MS spectroscopy, as well as the the 11β-hydroxymethyl, 3β-hydroxy and 4α-methyl stereochemistry. The crystal structure is built through a network of O—H...O hydrogen bonds involving the three hydroxyl groups that are present in the molecular skeleton.

  6. Humulane and germacrane sesquiterpenes from Ferula lycia.

    Science.gov (United States)

    Alkhatib, Racha; Hennebelle, Thierry; Joha, Sami; Roumy, Vincent; Güzel, Yelda; Biabiany, Murielle; Idziorek, Thierry; Preudhomme, Claude; Quesnel, Bruno; Sahpaz, Sevser; Bailleul, François

    2010-04-23

    Five new juniferol esters (1-5), along with six known humulane derivatives (6-11), were isolated from the roots of Ferula lycia, an endemic Turkish species. The fruits of the same species were also investigated and led to the isolation of these same compounds, as well as two known germacrane esters (12 and 13). All isolated sesquiterpenes were assayed for cytotoxicity against two tyrosine kinase inhibitor-resistant cell lines, K562R and DA1-3b/M2(BCR-ABL). The two most active compounds, juniferinin (7) and 6-beta-p-hydroxybenzoyloxygermacra-1(10),4-diene (12), were moderately active against Raji lymphoma cells but also displayed some toxicity against healthy bone marrow cells.

  7. Bioactive sesquiterpene coumarins from Ferula pseudalliacea.

    Science.gov (United States)

    Dastan, Dara; Salehi, Peyman; Reza Gohari, Ahmad; Ebrahimi, Samad Nejad; Aliahmadi, Atousa; Hamburger, Matthias

    2014-08-01

    One new and five known sesquiterpene coumarins were isolated from the roots of Ferula pseudalliacea. The structures were elucidated by 1D and 2D NMR, and HR-ESIMS data as 4'-hydroxy kamolonol acetate (1), kamolonol (2), szowitsiacoumarin A (3), farnesiferon B (4), farnesiferol C (5), and flabellilobin A (6). The absolute configuration of compounds 1, 2, and 4 was established by comparison of experimental and simulated electronic circular dichroism spectra using time dependence density function theory. 4'-Hydroxy kamolonol acetate and kamolonol showed antibacterial activity against Heliobacter pylori and Staphylococcus aureus at a concentration of 64 µg/mL. Kamolonol, 4'-hydroxy kamolonol acetate, and farnesiferon B displayed a cytotoxic activity in HeLa cells, with an IC50 of 3.8, 4.5, and 7.7 µM, respectively.

  8. Guaianolide sesquiterpenes from Pulicaria crispa (Forssk.) Oliv.

    Science.gov (United States)

    Stavri, Michael; Mathew, K T; Gordon, Andrew; Shnyder, Steven D; Falconer, Robert A; Gibbons, Simon

    2008-06-01

    A phytochemical study of the asteraceous herb Pulicaria crispa (Forssk.) Oliv. resulted in the characterisation of three guaianolide sesquiterpenes, 2alpha,4alpha-dihydroxy-7alphaH,8alphaH,10alphaH-guaia-1(5),11(13)-dien-8beta,12-olide (1), 1alpha,2alpha-epoxy-4beta-hydroxy-5alphaH,7alphaH,8alphaH,10alphaH-guaia-11(13)-en-8beta,12-olide (2) and 5,10-epi-2,3-dihydroaromatin (3). The structures were assigned on the basis of extensive 1 and 2D NMR experiments. Compound 3 exhibited weak antimycobacterial activity against Mycobacterium phlei with a minimum inhibitory concentration of 0.52 mM and cytotoxicity (IC50 of 5.8+/-0.2 microM) in a human bladder carcinoma cell line, EJ-138.

  9. Systemic allergic dermatitis caused by sesquiterpene lactones

    DEFF Research Database (Denmark)

    Paulsen, Evy

    2017-01-01

    Patients with Compositae sensitization are routinely warned against the ingestion of vegetables, spices, teas and herbal remedies from this family of plants. The evidence for the occurrence of systemic allergic dermatitis caused by sesquiterpene lactone-containing plants is mostly anecdotal...... and based on statements from patients rather than scientific data. However, a few clinical reports on accidental sensitization and exposure and oral challenge prove the existence of this kind of reaction, most convincingly for strong contact allergens such as costunolide in bay leaves, and less so for weak...... allergens such as those of lettuce. Other Compositae species suspected of causing systemic reactions are artichoke, mugwort, yarrow, dandelion, feverfew, and elecampane. Some Compositae vegetables and teas, such as lettuce and chamomile tea, may induce systemic reactions through both humoral and cell...

  10. A New Sesquiterpene and a New Norsesquiterpene from Cacalia deltophylla

    Institute of Scientific and Technical Information of China (English)

    Ying WANG; Cheng Shan YUAN; Xiao Long WANG; Zhong Jian JIA

    2003-01-01

    A new sesquiterpene and a new norsesquiterpene were isolated from the whole plant of Cacalia deltophylla (Maxim) Mattf. Their structures were elucidated as deltocacalone (1) and deltonorcacalol (2) by spectroscopic methods including 2D NMR.

  11. Two new diterpene and sesquiterpene from Pteris dispar

    Institute of Scientific and Technical Information of China (English)

    Zhan Ping Gou; Nian Ci Liang; Jie Hou; Li Li; Yan Tian; Chang Yuan Wang; Xun Cui; Bao Jing Zhang; Xiao Chi Ma

    2011-01-01

    A new diterpene and a new sesquiterpene were isolated from Pteris dispar and identified on the basis of spectral data including 2D NMR. Compounds 1 and 2 showed potent cytotoxic activity against KB cell.

  12. Functional Characterization of Sesquiterpene Synthase from Polygonum minus

    Directory of Open Access Journals (Sweden)

    Su-Fang Ee

    2014-01-01

    Full Text Available Polygonum minus is an aromatic plant, which contains high abundance of terpenoids, especially the sesquiterpenes C15H24. Sesquiterpenes were believed to contribute to the many useful biological properties in plants. This study aimed to functionally characterize a full length sesquiterpene synthase gene from P. minus. P. minus sesquiterpene synthase (PmSTS has a complete open reading frame (ORF of 1689 base pairs encoding a 562 amino acid protein. Similar to other sesquiterpene synthases, PmSTS has two large domains: the N-terminal domain and the C-terminal metal-binding domain. It also consists of three conserved motifs: the DDXXD, NSE/DTE, and RXR. A three-dimensional protein model for PmSTS built clearly distinguished the two main domains, where conserved motifs were highlighted. We also constructed a phylogenetic tree, which showed that PmSTS belongs to the angiosperm sesquiterpene synthase subfamily Tps-a. To examine the function of PmSTS, we expressed this gene in Arabidopsis thaliana. Two transgenic lines, designated as OE3 and OE7, were further characterized, both molecularly and functionally. The transgenic plants demonstrated smaller basal rosette leaves, shorter and fewer flowering stems, and fewer seeds compared to wild type plants. Gas chromatography-mass spectrometry analysis of the transgenic plants showed that PmSTS was responsible for the production of β-sesquiphellandrene.

  13. Dynamic accumulation of sesquiterpenes in essential oil of Pogostemon cablin

    Directory of Open Access Journals (Sweden)

    Ying Chen

    2014-12-01

    Full Text Available Sesquiterpenes Essential oil produced by patchouli was one of the most important naturally occurring base materials used in the perfume industry, containing various sesquiterpenes. Three different parts (leaves, stems and roots of Pogostemon cablin (Blanco Benth., Lamiaceae, were profiled in relation to different maturation phases in this paper, evaluating the variations in content of the major sesquiterpenes in the essential oil. Twelve sesquiterpenes were analyzed by GC-MS throughout the maturity of P. cablin. Patchouli alcohol (37.54%-51.02% in leaves, 28.24%-41.96% in stems and 14.55%-35.12% in roots was the major sesquiterpene during the maturation of the plant. The average content of several other sesquiterpenes (α-bulnesene, α-guaiene, seychellene, β-humulene and caryophyllene were higher than 3% among leaves, stems and roots. The content of essential oil, patchouli alcohol, α-bulnesene and several other compounds were highly accumulated at 210 days of maturation after cultivation of P. cablin. Thus, this period was the best moment to exploit the maximum level of these high value-added compounds in P. cablin. Furthermore, our results indicated that the essential oil extracted from leaves of P. cablin has the highest potential to be used in the perfume industry.

  14. Inhibition of a plant sesquiterpene cyclase by mevinolin.

    Science.gov (United States)

    Vögeli, U; Chappell, J

    1991-07-01

    The specificity of mevinolin as an inhibitor of sterol and sesquiterpene metabolism in tobacco cell suspension cultures was examined. Exogenous mevinolin inhibited [14C]acetate, but not [3H]mevalonate incorporation into free sterols. In contrast, mevinolin inhibited the incorporation of both [14C]acetate and [3H]mevalonate into capsidiol, an extracellular sesquiterpene. Microsomal 3-hydroxy-3-methylglutaryl Coenzyme A reductase was inhibited greater than 90% by microM mevinolin, while squalene synthetase was insensitive to even 600 microM mevinolin. Sesquiterpene cyclase, the first branch point enzyme specific for sesquiterpene biosynthesis, was inhibited in a dose-dependent manner by mevinolin with a 50% reduction in activity at 100 microM. Kinetic analysis indicated that the mechanism for inhibition was complex with mevinolin acting as both a competitive and noncompetitive inhibitor. The results suggest that the mevinolin inhibition of [3H]mevalonate incorporation into extracellular sesquiterpenes can, in part, be attributed to a secondary, but specific, site of inhibition, the sesquiterpene cyclase.

  15. Sesquiterpene lactones. XXXVI. Sesquiterpene lactones in several subgenera of the genus Centaurea L.

    Directory of Open Access Journals (Sweden)

    Gerard Nowak

    2014-01-01

    Full Text Available The occurrence of both known and new sesquiterpene lactones was determined in six species classified in different subgenera of Centaurea L. Chlorojanerin, cynaropicrin and janerin were isolated from C. phaeopappoides Bordz. and C. thracica (Janka Hayek. C. marschalliana Spreng. was found to contain acroptilin, chlorojanerin, cebellin D and janerin while C. adjarica Alb. had repin, acroptilin, chlorojanerin, centaurepensin, janerin, repidiolide, cebellin D, E, F and L A new, hitherto underscribed cebellin J quaianolide was found in C. bella Trautv. and another germacranolide, 3α, 15-dihydroxycostunolide was found in C. sphaerocephala subsp. lusitanica (Boiss. et Reuter Nyman.

  16. Systematic vibration thermodynamic properties of bromine

    Science.gov (United States)

    Liu, G. Y.; Sun, W. G.; Liao, B. T.

    2015-11-01

    Based on the analysis of the maturity and finiteness of vibrational levels of bromine molecule in ground state and evaluating the effect on statistical computation, according to the elementary principles of quantum statistical theorem, using the full set of bromine molecular vibrational levels determined with algebra method, the statistical contribution for bromine systematical macroscopic thermodynamic properties is discussed. Thermodynamic state functions Helmholtz free energy, entropy and observable vibration heat capacity are calculated. The results show that the determination of full set of vibrational levels and maximum vibrational quantum number is the key in the correct statistical analysis of bromine systematical thermodynamic property. Algebra method results are clearly different from data of simple harmonic oscillator and the related algebra method results are no longer analytical but numerical and are superior to simple harmonic oscillator results. Compared with simple harmonic oscillator's heat capacities, the algebra method's heat capacities are more consistent with the experimental data in the given temperature range of 600-2100 K.

  17. Two new brominated diterpenes from Laurencia decumbens

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Two new brominated diterpenes, namely, laurendecumtriol and 11-deacetylpinnaterpene C, were isolated and identified from the marine red alga Laurencia decumbens. Their structures were established on the basis of various NMR spectroscopic techniques and HR-ESI-MS analyses.

  18. Stability and metastability of bromine clathrate polymorphs.

    Science.gov (United States)

    Nguyen, Andrew H; Molinero, Valeria

    2013-05-23

    Clathrate hydrates are crystals in which water forms a network of fully hydrogen-bonded polyhedral cages that contain small guests. Clathrate hydrates occur mostly in two cubic crystal polymorphs, sI and sII. Bromine is one of two guests that yield a hydrate with the tetragonal structure (TS), the topological dual of the Frank-Kasper σ phase. There has been a long-standing disagreement on whether bromine hydrate also forms metastable sI and sII crystals. To date there are no data on the thermodynamic range of stability (e.g., the melting temperatures) of the metastable polymorphs. Here we use molecular dynamics simulations with the coarse-grained model of water mW to (i) investigate the thermodynamic stability of the empty and guest-filled the sI, sII, TS, and HS-I hydrate polymorphs, (ii) develop a coarse-grained model of bromine compatible with mW water, and (iii) evaluate the stability of the bromine hydrate polymorphs. The mW model predicts the same relative energy of the empty clathrate polymorphs and the same phase diagram as a function of water-guest interaction than the fully atomistic TIP4P water model. There is a narrow region in water-guest parameter space for which TS is marginally more stable than sI or sII. We parametrize a coarse-grained model of bromine compatible with mW water and use it to determine the order of stability of the bromine hydrate polymorphs. The melting temperatures of the bromine hydrate polymorphs predicted by the coarse-grained model are 281 ± 1 K for TS, 279 ± 1 K for sII, and 276 ± 1 K for sI. The closeness of the melting temperatures supports the plausibility of formation of metastable sII and sI bromine hydrates.

  19. Pulsed Bromine-81 Nuclear Quadrupole Resonance Spectroscopy of Brominated Flame Retardants and Associated Polymer Blends.

    Science.gov (United States)

    Mrse, Anthony A.; Lee, Youngil; Bryant, Pamela L.; Fronczek, Frank R.; Butler, Leslie G.; Simeral, Larry S.

    1998-03-01

    The dispersion of brominated flame retardants in polymers is monitored with bromine-81 NQR using a pulse NQR spectrometer. The NQR spectrometer consists of a homemade 10-300 MHz single-channel NMR console coupled to a broadly tunable probe. The probe is a loop-gap resonator usable from 220 to 300 MHz, and automatically tuned over any 5 MHz region with a stepping motor and an RF bidirectional coupler. Bromine-81 NQR spectra of several brominated aromatic flame retardants, as pure materials and in polymers, were recorded in the range of 227 to 256 MHz in zero applied magnetic field. Two factors affect the bromine-79/81 NQR transition frequencies in brominated aromatics: electron withdrawing substituents on the ring and intermolecular contacts with other bromine atoms in the crystal structure. An existing model for substituents is updated and a point charge model for the intermolecular contacts is developed. In this study, we exploit the bromine-81 NQR transition frequency dependence on intermolecular contacts to learn how a flame retardant is dispersed in a polymer matrix.

  20. Seasonal variation in sesquiterpene lactone concentration and composition of forage chicory (Cichorium intybus L.) cultivars

    Science.gov (United States)

    Chicory (Cichorium intybus L.) herbage contains sesquiterpene lactones that are believed to help control gastrointestinal nematodes in small ruminants. Because the anthelmintic effect could be related to both total sesquiterpene lactone concentration and the proportions of the principal constituent...

  1. Cytotoxic sesquiterpene lactones and other constituents of Centaurea omphalotricha

    Energy Technology Data Exchange (ETDEWEB)

    Kolli, El Hadj; Leon, Francisco; Benayache, Samir, E-mail: jfleon@ipna.csic.es, E-mail: sbenayache@yahoo.com [Laboratoire de Valorisation des Ressources Naturelles et Synthese de Substances Bioactives, Equipe Associee a l' A.N.D.R.S., Universite Mentouri, Constantine (Algeria); Benayache, Fadila [Laboratoire de Phytochimie et Analyses Physico-Chimiques et Biologiques, Universite Mentouri, Constantine (Algeria); Estevez, Sara; Quintana, Jose; Estevez, Francisco [Departamento de Bioquimica, Unidad Asociada al CSIC, Facultad de Ciencias de la Salud, Universidad de Las Palmas de Gran Canaria (Spain); Instituto Canario de Investigacion del Cancer, Las Palmas de Gran Canaria, Gran Canaria (Spain); Brouard, Ignacio; Bermejo, Jaime [Instituto de Productos Naturales y Agrobiologia, CSIC, La Laguna, Tenerife (Spain)

    2012-05-15

    Phytochemical research of the aerial parts of Centaurea omphalotricha led to the isolation of three new sesquiterpene lactones, 4'-acetyl cynaropicrin, 4'-acetyl cebellin F and 15-acetyl dehydromelitensin, together with twelve known compounds, seven sesquiterpene lactones, two isoprenoids and three flavonoids. The structures of the new compounds were elucidated by means of extensive 1D and 2D NMR, and MS, and by comparison with reported data in the literature. The effect of sesquiterpene lactones on the viability of the human tumor cell lines HL-60 and U937 was also investigated and 3-acetyl cynaropicrin, and 4'-acetyl cynaropicrin were found to be the most cytotoxic compounds against human leukemia cells with an IC{sub 50} values of 2.0 =- 0.9 and 5.1 +- 0.4 {mu}mol L{sup -1}, respectively. (author)

  2. A, a Brominated Flame Retardant

    Directory of Open Access Journals (Sweden)

    Tomomi Takeshita

    2013-01-01

    Full Text Available Tetrabromobisphenol A (TBBPA, a brominated flame retardant, has been found to exacerbate pneumonia in respiratory syncytial virus- (RSV- infected mice. We examined the effect of Brazilian propolis (AF-08 on the exacerbation of RSV infection by TBBPA exposure in mice. Mice were fed a powdered diet mixed with 1% TBBPA alone, 0.02% AF-08 alone, or 1% TBBPA and 0.02% AF-08 for four weeks and then intranasally infected with RSV. TBBPA exposure increased the pulmonary virus titer and level of IFN-γ, a representative marker of pneumonia due to RSV infection, in the lungs of infected mice without toxicity. AF-08 was significantly effective in reducing the virus titers and IFN-γ level increased by TBBPA exposure. Also, AF-08 significantly reduced proinflammatory cytokine (TNF-α and IL-6 levels in the lungs of RSV-infected mice with TBBPA exposure, but Th2 cytokine (IL-4 and IL-10 levels were not evidently increased. Neither TBBPA exposure nor AF-08 treatment affected the anti-RSV antibody production in RSV-infected mice. In flow cytometry analysis, AF-08 seemed to be effective in reducing the ratio of pulmonary CD8a+ cells in RSV-infected mice with TBBPA exposure. TBBPA and AF-08 did not exhibit anti-RSV activity in vitro. Thus, AF-08 probably ameliorated pneumonia exacerbated by TBBPA exposure in RSV-infected mice by limiting excess cellular immune responses.

  3. Abiotic Bromination of Soil Organic Matter.

    Science.gov (United States)

    Leri, Alessandra C; Ravel, Bruce

    2015-11-17

    Biogeochemical transformations of plant-derived soil organic matter (SOM) involve complex abiotic and microbially mediated reactions. One such reaction is halogenation, which occurs naturally in the soil environment and has been associated with enzymatic activity of decomposer organisms. Building on a recent finding that naturally produced organobromine is ubiquitous in SOM, we hypothesized that inorganic bromide could be subject to abiotic oxidations resulting in bromination of SOM. Through lab-based degradation treatments of plant material and soil humus, we have shown that abiotic bromination of particulate organic matter occurs in the presence of a range of inorganic oxidants, including hydrogen peroxide and assorted forms of ferric iron, producing both aliphatic and aromatic forms of organobromine. Bromination of oak and pine litter is limited primarily by bromide concentration. Fresh plant material is more susceptible to bromination than decayed litter and soil humus, due to a labile pool of mainly aliphatic compounds that break down during early stages of SOM formation. As the first evidence of abiotic bromination of particulate SOM, this study identifies a mechanistic source of the natural organobromine in humic substances and the soil organic horizon. Formation of organobromine through oxidative treatments of plant material also provides insights into the relative stability of aromatic and aliphatic components of SOM.

  4. 40 CFR 721.2925 - Brominated aromatic ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated aromatic ester. 721.2925... Substances § 721.2925 Brominated aromatic ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a brominated aromatic ester (PMN...

  5. 40 CFR 721.3085 - Brominated phthalate ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated phthalate ester. 721.3085... Substances § 721.3085 Brominated phthalate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as brominated phthalate ester (PMN P-90-581)...

  6. Sesquiterpene lactone glycosides from the roots of Ferula varia.

    Science.gov (United States)

    Kurimoto, Shin-ichiro; Suzuki, Kyoko; Okasaka, Mamoru; Kashiwada, Yoshiki; Kodzhimatov, Olimjion Kakhkharovich; Takaishi, Yoshihisa

    2012-01-01

    Seven new sesquiterpene lactone glycosides (1-7) were isolated from the H2O-soluble fraction from the MeOH extract of the roots of Ferula varia. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of compounds 1 and 2 were determined by modified Mosher's method.

  7. A New Sesquiterpene from the Roots of Biondia hemsleyana

    Institute of Scientific and Technical Information of China (English)

    Xing Gen TAN; Pei CAO; Shu Lin PENG; Li Sheng DING

    2005-01-01

    A new sesquiterpene with a unusual modified germacrane skeleton was isolated from the ethanol extracts of the roots of Biondia hemsleyana and its structure was elucidated as 3β-hydroxy4,14-cyclogermacra-11-en-9-one by the spectroscopic methods and X-ray crystallography.

  8. Immunotoxicity assessment of cadinene sesquiterpenes from Eupatorium adenophorum in mice

    Institute of Scientific and Technical Information of China (English)

    OUYANG Can-bin; LIU Xiao-man; YAN Dong-dong; LI Yuan; WANG Qiu-xia; CAO Ao-cheng; GUO mei-xia

    2016-01-01

    Sesquiterpenes inEupatorium adenophorum are abundant in leaves and have great development potential as biopesti-cides. The toxicity of sesquiterpenes in immune cels and their corresponding immune functions are not fuly understood. We evaluated the immunotoxicity of two cadinene sesquiterpenes 2-deoxo-2-(acetyloxy)-9-oxoageraphorone (DAOA) and 9-oxo-10,11-dehydro-agerophorone (ODA) by using histopathology and toxicology methodsin vitro and in vivo in lymphocytes and natural kiler cels in Kunming mice. The mice were given single doses of 75, 150 and 300 mg kg−1 body weight (BW) of DAOA/ODA every day for a week. Serious damage to the thymus and spleen was found in tissue images with clear lysis reduction numbers and a loosened arrangement of splenocytes and thymocytes to the mice treated with 150–300 mg kg−1 DAOA/ODA. Mice cytology was also affected with signiifcant celular alterations, increased splenocytes apoptosis rates (P<0.01), proliferation reduction (P<0.05) and natural kiler cels activities reduction (P<0.05) when given 150–300 mg kg−1 DAOA/ODA, the severities of which were dose-dependent. However, a 75 mg kg−1 dose of DAOA/ODA showed no change in tissue or cytology after the 7 day treatment, and therefore was considered to be within acceptable safety parameters. Taken together, cadinene sesquiterpenes, as a type of toxic botanical component, have low environmental risks in smal doses and should be further studied for their use as biopesticides.

  9. A New Degraded Sesquiterpene from Marine Actinomycete Streptomyces sp. 0616208

    Institute of Scientific and Technical Information of China (English)

    Xiu Chao XIE; Wen Li MEI; You Xing ZHAO; Kui HONG; Hao Fu DAI

    2006-01-01

    A new degraded sesquiterpene was isolated from the marine actinomycete Streptomyces sp. 0616208. Its structure was elucidated as (1α, 4aα, 5α, 7β, 8aβ)-5, 8a-dimethyl-decahydrona-phthalene-1, 4a, 7-triol on the basis of spectroscopic data.

  10. A New Sesquiterpene Lactones Glucoside from Notoseris psilolepis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new sesquiterpene lactone glucoside, notoserolide C (1), was isolated from the whole plant of Notoseris psilolepis Shih. By means of spectral analysis including MS, NMR (1H NMR, 13C NMR, 1H-1H COSY, HMQC, HMBC) and X-ray diffraction, the structure of notoserolide C was established as cichorioside B angelate.

  11. A New Sesquiterpene from the Roots of Lindera strychnifolia

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new sesquiterpene lactone, strychnilactone (1), together with five known sesquite- rpenoids, linderane (2), lindenenol (3), linderalactone (4), hydroxylindestenolide (5), pseudoneo- linderane (6) have been isolated from the extracts of Supercritical Fluid Extraction of Lindera strychnifolia. The structure of the new compound was elucidated by means of spectroscopic analysis. And the relative configuration of 1 was assigned on the basis of NOE analysis.

  12. A new eremophilane-type sesquiterpene from Ligularia virgaurea

    Institute of Scientific and Technical Information of China (English)

    Dong Qing Fei; Zhan Xin Zhang

    2009-01-01

    A new eremophilane-type sesquiterpene, 1α,8β,10β-trihydroxy-6β-(2-methylacryloyl)oxyeremophil-7(11)-en-8α,12-olide, was isolated from the roots of Ligularia virgaurea. Its structure was established on the basis of various spectroscopic analyses, including the 1D, 2D NMR techniques and HR-ESI-MS.

  13. A new sesquiterpene trilactone from the roots of Ginkgo biloba

    Institute of Scientific and Technical Information of China (English)

    Ping Yu; Jing Yu Liang

    2009-01-01

    A new sesquiterpene trilactone, named bilobanol (1), along with four known terpene trilactones (ginkgolide A, B, C and bilobalide) were isolated from the roots of Ginkgo biloba collected in Jiangsu Province, China. The structure elucidation was accomplished by 1D and 2D NMR methods, HR-ESI-MS, and CD spectrum.

  14. A new modified sesquiterpene glycoside from Cupressus chengiana.

    Science.gov (United States)

    Lin, Yan; Li, Rong-Jiao; Li, Yan; McGarvey, Brian D; Wu, Hai-Feng; Wang, Xiao-Ling

    2014-01-01

    A new sesquiterpene glycoside, cupressusoside (1), and five known compounds were isolated from the 70% aqueous ethanol extract of the branches and leaves of Cupressus chengiana. Their structures were elucidated by using spectroscopic methods. All the isolates expressed no remarkable cytotoxic activity against colon carcinoma (HCT-8) and breast cancer (MCF-7) cell lines, with IC50>40 mg/mL.

  15. Brominated flame retardants and endocrine disruption

    NARCIS (Netherlands)

    Vos, J.G.; Becher, G.; Berg, van den M.; Boer, de J.; Leonards, P.E.G.

    2003-01-01

    From an environmental point of view, an increasing important group of organohalogen compounds are the brominated flame retardants (BFRs), which are widely used in polymers and textiles and applied in construction materials, furniture, and electronic equipment. BFRs with the highest production volume

  16. Bromination of selected pharmaceuticals in water matrices.

    Science.gov (United States)

    Benitez, F Javier; Acero, Juan L; Real, Francisco J; Roldan, Gloria; Casas, Francisco

    2011-11-01

    The bromination of five selected pharmaceuticals (metoprolol, naproxen, amoxicillin, phenacetin, and hydrochlorothiazide) was studied with these compounds individually dissolved in ultra-pure water. The apparent rate constants for the bromination reaction were determined as a function of the pH, obtaining the sequence amoxicillin>naproxen>hydrochlorothiazide≈phenacetin≈metoprolol. A kinetic mechanism specifying the dissociation reactions and the species formed for each compound according to its pK(a) value and the pH allowed the intrinsic rate constants to be determined for each elementary reaction. There was fairly good agreement between the experimental and calculated values of the apparent rate constants, confirming the goodness of the proposed reaction mechanism. In a second stage, the bromination of the selected pharmaceuticals simultaneously dissolved in three water matrices (a groundwater, a surface water from a public reservoir, and a secondary effluent from a WWTP) was investigated. The pharmaceutical elimination trend agreed with the previously determined rate constants. The influence of the main operating conditions (pH, initial bromine dose, and characteristics of the water matrix) on the degradation of the pharmaceuticals was established. An elimination concentration profile for each pharmaceutical in the water matrices was proposed based on the use of the previously evaluated apparent rate constants, and the theoretical results agreed satisfactorily with experiment. Finally, chlorination experiments performed in the presence of bromide showed that low bromide concentrations slightly accelerate the oxidation of the selected pharmaceuticals during chlorine disinfection.

  17. A Facile Synthesis of Two Sesquiterpenes Methyl Ether

    Institute of Scientific and Technical Information of China (English)

    DU Zhen-Ting; ZHANG Yan-Mei; WANG Zi-Kun; WU Tong-Xing; PAN Xin-Fu

    2003-01-01

    @@ Bisabolane sesquiterpenes are a big family of naturally occurring products with significantly biological activities most of which can be separated from Chinese traditional medicines. Parahigginone (1a) was firstly separated as a bisabolane by Shen Y. C. et al. from the Taiwan marine sponges in 1999, [1] it shows very promising antitumor activity.[1] As far as we know, there is no synthetic report on it. Curcuphenol (2a) was a cytotoxic sesquiterpene which was first discovered in Pseudopterogorgia rigida[2,3] which has been synthesized by Frank[2] and Tsutomu[4] before. In order to study the relationship between the structures and the activities, we have synthesized parahiggi none methyl ether (1) and curcuphenol methyl ether (2) in six steps successfully, and the stereoselective synthesis is carried out in progress.

  18. New sesquiterpene coumarins from the roots of Ferula flabelliloba.

    Science.gov (United States)

    Iranshahi, Mehrdad; Kalategi, Farhad; Sahebkar, Amirhossein; Sardashti, Alireza; Schneider, Bernd

    2010-02-01

    Three new sesquiterpene coumarins, namely, farnesiferone B (1), flabellilobin A (2) and flabellilobin B (3), together with nine known compounds, ligupersin A, 7-epi-gamma-eudesmol, persicasulfide A, conferdione, umbelliprenin, conferone, feselol, lehmferin and farnesiferol B were isolated from the roots of Ferula flabelliloba Rech. f. & Aell. (Apiaceae). The structures of these compounds were elucidated by various 1- and 2-D NMR techniques as well as HREIMS.

  19. A Novel Sesquiterpene Isolated from Stereum sp. 8954

    Institute of Scientific and Technical Information of China (English)

    Guo Hong LI; Ke Qin ZHANG

    2005-01-01

    Stereumone A, a novel sesquiterpene was isolated from the fermentation broth of Stereum sp. 8954. Its structure was determined to be 5-hydroxy-6,6,9-trimethyl-4,8a-epoxy-2,3,4a,5,6,7,8a,9-octahydro-4H-naphtho[2,3-b]furan-8-one on the basis of the spectral data.

  20. Natural Sesquiterpene Lactones Induce Oxidative Stress in Leishmania mexicana

    OpenAIRE

    Patricia Barrera; Valeria P Sülsen; Esteban Lozano; Mónica Rivera; María Florencia Beer; Carlos Tonn; Martino, Virginia S.; Sosa, Miguel A.

    2015-01-01

    Leishmaniasis is a worldwide parasitic disease, caused by monoflagellate parasites of the genus Leishmania. In the search for more effective agents against these parasites, the identification of molecular targets has been attempted to ensure the efficiency of drugs and to avoid collateral damages on the host’s cells. In this work, we have Investigated some of the mechanisms of action of a group of natural sesquiterpene lactones that are effective against Leishmania mexicana mexicana promasti...

  1. Natural Sesquiterpene Lactones Induce Oxidative Stress in Leishmania mexicana

    Directory of Open Access Journals (Sweden)

    Patricia Barrera

    2013-01-01

    Full Text Available Leishmaniasis is a worldwide parasitic disease, caused by monoflagellate parasites of the genus Leishmania. In the search for more effective agents against these parasites, the identification of molecular targets has been attempted to ensure the efficiency of drugs and to avoid collateral damages on the host’s cells. In this work, we have investigated some of the mechanisms of action of a group of natural sesquiterpene lactones that are effective against Leishmania mexicana mexicana promastigotes. We first observed that the antiproliferative effect of mexicanin I (Mxc, dehydroleucodine (DhL, psilostachyin (Psi, and, at lesser extent, psilostachyin C (Psi C is blocked by 1.5 mM reduced glutathione. The reducing agent was also able to reverse the early effect of the compounds, suggesting that lactones may react with intracellular sulfhydryl groups. Moreover, we have shown that all the sesquiterpene lactones, except Psi C, significantly decreased the endogenous concentration of glutathione within the parasite. Consistent with these findings, the active sesquiterpene lactones increased between 2.7 and 5.4 times the generation of ROS by parasites. These results indicate that the induction of oxidative stress is at least one of the mechanisms of action of DhL, Mxc, and Psi on parasites while Psi C would act by another mechanism.

  2. Sesquiterpenes of Ocotea lancifolia (Lauraceae); Sesquiterpenos de Ocotea lancifolia (Lauraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Camargo, Maria Jose de; Miranda, Mayker Lazaro Dantas; Kagamida, Camila Miyuki; Rodrigues, Edilene Delphino; Garcez, Fernanda Rodrigues; Garcez, Walmir Silva, E-mail: walmir.garcez@ufms.br [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Centro de Ciencias Exatas e Tecnologia. Dept. de Quimica

    2013-10-01

    Six new eremophilane sesquiterpenes, (rel)-4{beta},5{beta},7{beta}-eremophil-9-en-12-oic acid (1), (rel)-4{beta},5{beta},7{beta}-eremophil-1(10)-en-12-oic acid (2), (rel)-4{beta},5{beta},7{beta}-eremophil-1(10)-en-2-oxo-12-oic acid (3), (rel)-4{beta},5{beta},7{beta}-eremophil-9-en-12,8{alpha}-olide (4), (rel)-4{beta},5{beta},7{beta}-eremophil-9-en-12,8{beta}-olide (5) and (rel)-4{beta},5{beta},7{beta}-eremophil-9{alpha},10{alpha}-epoxy-12-oic acid (6), were isolated from the leaves of a specimen of Ocotea lancifolia (Lauraceae). Two other known sesquiterpenes, 4{beta},5{beta},7{beta}-eremophil-11-en- 10{alpha}-ol (7) reported for the first time in the genus Ocotea, and the aromadendrene sesquiterpene, spathulenol (8), were also isolated. Their structures were determined on the basis of spectral data (MS, IR, UV and NMR-1D and 2D) and subsequent comparisons with the literature. (author)

  3. Cytotoxic sesquiterpene lactones from the aerial parts of Inula aucheriana.

    Directory of Open Access Journals (Sweden)

    Ahmad Reza Gohari

    2015-06-01

    Full Text Available Inula aucheriana DC is a member of the family Asteraceae which is known to produce cytotoxic secondary metabolites noted as sesquiterpene lactones. In the present study, sesquiterpene lactones inuchinenolide B, 6-deoxychamissonolide (stevin and 14-acetoxy-1β,5α,7αH-4β-hydroxy-guai-9(10,11(13-dien-12,8α-olide were isolated from I. aucheriana. Inuchinenolide B and 14-acetoxy-1β,5α,7αH-4β-hydroxy-guai-9(10,11(13-dien-12,8α-olide were further evaluated by the MTT (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyl tetrazolium bromide assay to demonstrate cytotoxic activity with IC50 values of (56.6, 19.0, (39.0, 11.8, and (55.7, 15.3 μg/mL against HepG-2, MCF-7 and A-549 cells, respectively. The cytotoxic activity of the two evaluated sesquiterpene lactones partly explains the cytotoxic activity that was previously observed for the extracts of Inula aucheriana. The isolated compounds could be further investigated in cancer research studies.

  4. Membrane-less hydrogen bromine flow battery.

    Science.gov (United States)

    Braff, William A; Bazant, Martin Z; Buie, Cullen R

    2013-01-01

    In order for the widely discussed benefits of flow batteries for electrochemical energy storage to be applied at large scale, the cost of the electrochemical stack must come down substantially. One promising avenue for reducing stack cost is to increase the system power density while maintaining efficiency, enabling smaller stacks. Here we report on a membrane-less hydrogen bromine laminar flow battery as a potential high-power density solution. The membrane-less design enables power densities of 0.795 W cm(-2) at room temperature and atmospheric pressure, with a round-trip voltage efficiency of 92% at 25% of peak power. Theoretical solutions are also presented to guide the design of future laminar flow batteries. The high-power density achieved by the hydrogen bromine laminar flow battery, along with the potential for rechargeable operation, will translate into smaller, inexpensive systems that could revolutionize the fields of large-scale energy storage and portable power systems.

  5. Membrane-less hydrogen bromine flow battery

    CERN Document Server

    Braff, W A; Buie, C R

    2014-01-01

    In order for the widely discussed benefits of flow batteries for electrochemical energy storage to be applied at large scale, the cost of the electrochemical stack must come down substantially. One promising avenue for reducing stack cost is to increase the system power density while maintaining efficiency, enabling smaller stacks. Here we report on a membrane-less, hydrogen bromine laminar flow battery as a potential high power density solution. The membrane-less design enables power densities of 0.795 W cm$^{-2}$ at room temperature and atmospheric pressure, with a round-trip voltage efficiency of 92\\% at 25\\% of peak power. Theoretical solutions are also presented to guide the design of future laminar flow batteries. The high power density achieved by the hydrogen bromine laminar flow battery, along with the potential for rechargeable operation, will translate into smaller, inexpensive systems that could revolutionize the fields of large-scale energy storage and portable power systems.

  6. Oxygenated products of sesquiterpenes in secondary organic aerosol

    Science.gov (United States)

    van Eijck, A.; Kampf, C.; Hoffmann, T.

    2012-04-01

    Secondary organic aerosol (SOA) has a huge impact on air quality and climate change. It influences the Earth radiative budget through absorbing, scattering and reflecting radiation as well as the formation of clouds because the particulates can act as cloud condensation nuclei (CCN). Furthermore, it plays an important role for human health. SOA is formed from gaseous precursors which get oxidized by ozone, OH- and NO3-radicals in the atmosphere. Due to their low vapor pressure these degradation products can nucleate to form new particles or they can condense on existing aerosol particles. Despite the major progress in research during the last few years the actual chemical composition as well as the contribution of various volatile organic compounds (VOCs) to the formation of secondary organic aerosol is still partially unknown. Recent studies indicate that sesquiterpenes play an important role in the formation of SOA because of the low volatility of their oxygenated products (Lee et al., 2006). Their emission is estimated to be about 14,8 Tg per year (Henze et al., 2008), however, these emission rates remain highly uncertain due to the lack of quantitative emission rate measurements. In addition, the knowledge about the actual atmospheric degradation mechanism and the main oxidation products of sesquiterpenes is quite limited. β-Caryophyllene, α-humulene, α-farnesene and β-farnesene are the most abundant sequiterpenes in many sesquiterpene emission profiles. But also aromadendren, α-bergamotene and δ-cadinene and germacrene-D can contribute significantly to some emission profiles (Duhl et al., 2008). To determine the major oxygenated products of sesquiterpenes in SOA, reaction chamber experiments with different sesquiterpenes and ozone were performed in a 100 L reaction chamber. To measure the time dependent formation of initial oxidation products, an APCI-IT-MS was directly connected to the reaction chamber. After 2 hours the APCI-IT-MS was replaced by a

  7. NMR investigation of non-brominated and brominated epoxy ester prepolymers

    Science.gov (United States)

    Žigon, M.; Osredkar, U.; Šebenik, A.

    1992-03-01

    1H, 13C and two-dimensional NMR spectroscopy has been used to investigate the structure of epoxy ester prepolymers, based on non-brominated DGEBA-type or brominated DGETBBA-type epoxy resins, and on an oligomeric carboxylic acid. In the presence of a quaternary phosphonium salt, besides diglycidylether of bisphenol A (DGEBA) or diglycidylether of tetrabromobisphenol A (DGETBBA) and their higher oligomers, monoesters with characteristic R-CH 2-CH(OH)-CH 2-OCOR' groups were detected in prevailing quantities. In dependence of the epoxy-carboxy ratio, isomeric monoesters with hydroxymethyl groups, diesters and diols might also be present.

  8. Ambient sesquiterpene concentration and its link to air ion measurements

    Directory of Open Access Journals (Sweden)

    B. Bonn

    2006-12-01

    Full Text Available Ambient air ion size distributions have been measured continuously at the Finnish boreal forest site in Hyytiälä since spring 2003. In general, these measurements show a maximum of air ions below 1.0 nm in diameter. But this physical characterization does not provide any information about the ion's chemical composition, which is one key question regarding the explanation of nucleation events observed. In this study we propose a link of the observed maximum of negative air ions between 0.56 and 0.75 nm to the so-called stabilised Criegee biradical, formed in the reaction of biogenic sesquiterpenes with ozone and predominantly destroyed by its reaction with ambient water vapour. Calculations of the electron and proton affinities of 120 kJ mol−1 (1.24 eV and of 960 kJ mol−1 support this link. Other possible candidates such as sulphuric acid derived clusters are unable to explain the observations made. By using this approach, we are able to calculate the ambient concentration of sesquiterpenes at the air ion instrument inlet with a high time resolution on the daily and seasonal scale. The estimated concentration is found to reveal the same seasonal pattern as emission measurements conducted at shoot level. As expected for biogenic VOCs, the concentration is obtained highest during summer (maximum values of about 100 pptv and smallest during winter (minimum less than 1 pptv. Because of the sesquiterpenes high reactivity and its low ambient concentrations, this approach can be a first step in understanding their emission and their impact on atmospheric chemistry in more detail. The findings presented are highly relevant for emission budgets too, since boreal forests are extended over large areas of the globe.

  9. Ambient sesquiterpene concentration and its link to air ion measurements

    Directory of Open Access Journals (Sweden)

    B. Bonn

    2007-06-01

    Full Text Available Ambient air ion size distributions have been measured continuously at the Finnish boreal forest site in Hyytiälä since spring 2003. In general, these measurements show a maximum of air ions below 1.0 nm in diameter. But this physical characterization does not provide any information about the ion's chemical composition, which is one key question regarding the explanation of nucleation events observed. In this study we propose a link of the observed maximum of negative air ions between 0.56 and 0.75 nm to the so-called stabilised Criegee biradical, formed in the reaction of biogenic sesquiterpenes with ozone and predominantly destroyed by its reaction with ambient water vapour. Calculations of the electron and proton affinities of 120 kJ mol−1 (1.24 eV and of 960 kJ mol−1 support this link. Other possible candidates such as sulphuric acid derived clusters are unable to explain the observations made. By using this approach, we are able to calculate the ambient concentration of sesquiterpenes at the air ion instrument inlet with a high time resolution on the daily and seasonal scale. The estimated concentration is found to reveal the same seasonal pattern as emission measurements conducted at shoot level. As expected for biogenic VOCs, the concentration is obtained highest during summer (maximum values of about 100 pptv and smallest during winter (minimum less than 1 pptv. Because of the sesquiterpenes high reactivity and its low ambient concentrations, this approach can be a first step in understanding their emission and their impact on atmospheric chemistry in more detail. The findings presented are highly relevant for emission budgets too, since boreal forests are extended over large areas of the globe.

  10. A New Eudesmane Sesquiterpene from Nigrospora oryzae, an Endophytic Fungus of Aquilaria sinensis

    Directory of Open Access Journals (Sweden)

    Dongli Li

    2014-07-01

    Full Text Available A new eudesmane-type sesquiterpene, 11 -hydroxy capitulatin B (1 , along with a known related sesquiterpene, capitulatin B (2, was isolated from the endophytic fungus Nigrospora oryzae A8 from Aquilaria sinensis, the only plant resource for agarwood production in China. This research demonstrates that the endophytic fungi from A. sinensis might play a role in the formation of agarwood.

  11. Two novel eremophilane sesquiterpenes from an endophytic Xylariaceous fungus isolated from leaves of Cupressus lusitanica

    OpenAIRE

    2010-01-01

    Two new eremophilane sesquiterpenes, cupressolide A and cupressolide B, along with two known sesquiterpenes, has been characterized from the EtOAc extract of a liquid medium where a Xylariaceous fungus, isolated as an endophytic fungus from health tissues of Cupressus lusitanica leaves, was cultivated. The structures of the isolated compounds were determined by analyses of their MS and NMR spectroscopic data.

  12. Comparison of simultaneous patch testing with parthenolide and sesquiterpene lactone mix

    DEFF Research Database (Denmark)

    Orion, E; Paulsen, E; Andersen, Klaus Ejner

    1998-01-01

    Several studies have pointed out that the sesquiterpene lactone (SL) mix is a safe, though inadequate, screen for Compositae allergy. To test the usefulness of the sesquiterpene lactone parthenolide as a supplementary Compositae screening test to the mix, both were included in the standard series...

  13. Cytotoxic and antibacterial activities of sesquiterpene lactones isolated from Tanacetum praeteritum subsp praeteritum

    NARCIS (Netherlands)

    Goren, N; Woerdenbag, HJ; BozokJohansson, C

    1996-01-01

    Ten sesquiterpene lactones and one sesquiterpene isolated from Tanacetum praeteritum subsp. praeteritum: 1 alpha,6 alpha-dihydroxyisocostic acid methyl ester (2), 1 alpha-hydroxy-1-deoxoarglanine (3), douglanin (5), santamarin (6), reynosin (7), 1-epi-tatridin B (8), ludovicin A (10), armexin (12),

  14. Two novel eremophilane sesquiterpenes from an endophytic Xylariaceous fungus isolated from leaves of Cupressus lusitanica

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Luciana S.; Rodrigues-Filho, Edson, E-mail: edson@dq.ufscar.b [Universidade Federal de Sao Carlos (DQ/UFSCar), SP (Brazil). Dept. de Quimica

    2010-07-01

    Two new eremophilane sesquiterpenes, cupressolide A and cupressolide B, along with two known sesquiterpenes, has been characterized from the EtOAc extract of a liquid medium where a Xylariaceous fungus, isolated as an endophytic fungus from health tissues of Cupressus lusitanica leaves, was cultivated. The structures of the isolated compounds were determined by analyses of their MS and NMR spectroscopic data. (author)

  15. Sesquiterpene lactones from Ferula oopoda and their cytotoxic properties.

    Science.gov (United States)

    Kasaian, Jamal; Iranshahy, Milad; Masullo, Milena; Piacente, Sonia; Ebrahimi, Fatemeh; Iranshahi, Mehrdad

    2014-01-01

    Two new sesquiterpene lactones, namely feruhodin A and feruhodin B, together with six known compounds, daucoeudesmanolactone, dehydrooopodin, oopodin, badkhysin, 7-demethylplastochromenol, and scoparone, were isolated from the roots of Ferula oopoda. The structures of these compounds were elucidated by 1D and 2D NMR techniques as well as high-resolution mass spectrometry. Cytotoxic effects of these compounds were evaluated against two human cancer cell lines including MCF7and K562 using the Alamar blue assay. The results showed that dehydrooopodin possessed significant cytotoxic effects with IC₅₀ values of 15 and 5 μM against MCF7 and K562, respectively.

  16. Aedes aegypti Larvicidal Sesquiterpene Alkaloids from Maytenus oblongata.

    Science.gov (United States)

    Touré, Seindé; Nirma, Charlotte; Falkowski, Michael; Dusfour, Isabelle; Boulogne, Isabelle; Jahn-Oyac, Arnaud; Coke, Maïra; Azam, Didier; Girod, Romain; Moriou, Céline; Odonne, Guillaume; Stien, Didier; Houël, Emeline; Eparvier, Véronique

    2017-02-24

    Four new sesquiterpene alkaloids (1-4) with a β-dihydroagrofuran skeleton and a new triterpenoid (5) were isolated from an ethyl acetate extract of Maytenus oblongata stems. Their structures were elucidated using 1D and 2D NMR spectroscopy as well as MS and ECD experiments. The M. oblongata stem EtOAc extract and the pure compounds isolated were tested for larvicidal activity against Aedes aegypti under laboratory conditions, and compounds 2 and 3 were found to be active.

  17. A novel methylated sesquiterpene from seagrass Posidonia oceanica (L.) Delile.

    Science.gov (United States)

    Hammami, Saoussen; Salem, Abdelkader Ben; Ashour, Mohamed L; Cheriaa, Jihène; Graziano, Guella; Mighri, Zine

    2013-01-01

    Phytochemical investigation of chloroform extract from the leaves of the marine plant Posidonia oceanica (L.) Delile (Posidoniaceae), yielded posidozinol, a new methylated sesquiterpene along with β-sitosterol and four known fatty acids: palmitic, palmitoleic, oleic and linoleic acids. The structure elucidation has been established on the basis of 1D- and 2D-NMR spectroscopy, GS/MS and ES mass spectrometry. Antibacterial effects of crude extracts from P. oceanica were evaluated against: Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Micrococcus luteus microorganisms.

  18. Selective cytotoxic eremophilane-type sesquiterpenes from Penicillium citreonigrum.

    Science.gov (United States)

    Yuan, Wei-Hua; Goto, Masuo; Hsieh, Kan-Yen; Yuan, Bo; Zhao, Yu; Morris-Natschke, Susan L; Lee, Kuo-Hsiung

    2015-01-01

    One new eremophilane-type sesquiterpene (1, citreopenin) was isolated from Penicillium citreonigrum (HQ738282), and the structure was elucidated by a combination of spectroscopic data interpretation and single-crystal X-ray diffraction analysis using Cu Kα radiation (CCDC 1030588). Compound 1 showed weak activity against KB-VIN (IC50 = 11.0 ± 0.156 μM), while the known compound 3 exhibited selective cytotoxicity against MDA-MB-231 triple-negative breast cancer (TNBC) (IC50 = 5.42 ± 0.167 μM).

  19. New Sinularianin Sesquiterpenes from Soft Coral Sinularia sp.

    Directory of Open Access Journals (Sweden)

    Bin Yang

    2013-12-01

    Full Text Available Four new sesquiterpenes, sinularianins C–F (3–6, together with known sinularianins A (1 and B (2 were identified from a South China Sea soft coral Sinularia sp. Compounds 1–6 were evaluated for inhibition of NF-κB activation using the cell-based HEK293 NF-κB luciferase reporter gene assay. Compounds 1 and 4 were exhibited a potent effect with inhibitory rates of 41.3% and 43.0% at the concentration of 10 µg/mL, respectively.

  20. Two new sesquiterpene lactones from Montanoa tomentosa ssp. microcephala.

    Science.gov (United States)

    Braca, A; Cioffi, G; Morelli, I; Venturella, F; Pizza, C; De Tommasi, N

    2001-11-01

    Two new sesquiterpene lactones: 8alpha-(4'-acetoxymethacryloyloxy)-3alpha,9beta-dihydroxy-1(10)E,4Z,11(13)-germacratrien-12,6alpha-olide (1) and 8alpha-(2'E)-(2'-acetoxymethyl-2'-butenoyloxy)-3alpha,9beta-dihydroxy-1(10)E,4Z,11(13)-germacratrien-12,6alphaolide (2), together with the known zoapatanolide A were isolated from the aerial parts of Montanoa tomentosa Cerv. in La Llave et Lex ssp. microcephala (Sch. Bip. In K. Koch) V.A. Funk (Asteraceae). The structures of all compounds were established on the basis of 1D, 2D NMR, and EIMS analysis.

  1. A New Insecticidal Sesquiterpene Ester from Celastrus Angulatus

    Directory of Open Access Journals (Sweden)

    Shao-peng Wei

    2009-03-01

    Full Text Available A new sesquiterpene polyol ester with a β-dihydroagarofuran skeleton, NW37 (1, and three known compounds NW13 (2, NW16 (3 and NW35 (4 were isolated by bioassay-guided fractionation from the highly polar MeOH extracts of the root bark of Celastrus angulatus. Their chemical structures were elucidated mainly by analyses of MS and NMR spectral data. The insecticidal activity of compound 1 against 4th instar Mythimna separata larvae with a KD50 value of 252.3 μg·g-1 was demonstrated.

  2. Polyvinylpolypyrrolidone-bromine complex: Mild and efficient polymeric reagent for bromination of activated aromatic compounds

    Institute of Scientific and Technical Information of China (English)

    Masoud Mokhtary; Moslem M. Lakouraj

    2011-01-01

    Mild and efficient method for bromination of electron-rich aromatic compounds is described using polyvinylpolypyrrolidonebromine complex (PVPP-Br2). The reaction proceeded smoothly with phenols and N,N-alkylated amines to afford the corresponding monobrominated product in good yields at ambient temperature.

  3. The Addition of Bromine to 1,2-Diphenylethene

    Science.gov (United States)

    Amburgey-Peters, Judith C.; Haynes, Leroy W.

    2005-01-01

    The bromination of 1,2-diphenylethene, using a variety of solvents and brominating agents, can be used in both introductory and advanced organic chemistry courses. The reactions can be used to illustrate the effects of changing solvents and reagents, as well as to reveal interesting aspects of organic reaction mechanisms.

  4. Fire-retardant coatings based on organic bromine/phenoxy or brominated epoxy systems

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.M.; Chiu, Ing L.

    1989-06-01

    Thin phenoxy and brominated epoxy/curing agent films were prepared by solvent casting on Mylar and Kapton. Thicknesses were approximated assuming volume additivity. Important parameters were uniformity of thickness, distribution of the bromine-containing fire retardant, adhesion to carrier substrate (either Mylar or Kapton), and uniformity of the coating, i.e., absence of pinholes, blush, blistering, etc. Wetting behavior was modified using fluoro, silicone or polyurea surfactants. Several solvent systems were examined and a ternary solvent system was ultimately used. Distribution of fire-retardant bromine was analyzed using electron microprobe, x-ray fluorescence and wet chemical methods. Significant discrepancies in the /mu/m-scale analyses of the microprobe measurements have not been resolved. Some of the brominated fire retardants were insoluble in the resin systems and the phase separation was immediately obvious. Similarly, some of the crystallizable epoxies could not be cast easily into homogeneous, amorphous films. Castings were made on a standard 8'' /times/ 10'' aluminum vacuum plate polished with jeweler's rouge prior to every casting. Solvent was removed in a forced air or vacuum oven. Removal and/or curing was accelerated with temperature. The fire-retardant bromine was required to be stable in alcohol/salt solutions. Final formulation used after a significant amount of testing was phenoxy resin PKHC in a ternary solvent system composed of methylethyl ketone, cellosolve acetate and toluene. Tetrabromobisphenol A was used as the flame retardant with FC-430 as surfactant. The dying schedule was 30 minutes at 150/degree/C. 4 refs., 6 figs., 3 tabs.

  5. Formation of THMs and HANs during bromination of Microcystis aeruginosa

    Institute of Scientific and Technical Information of China (English)

    Yunzhu Pu; Lingzhao Kong; Xin Huang; Guoji Ding; Naiyun Gao

    2013-01-01

    Bromine-contained disinfectants and biocides are widely used in swimming pools,recreational waters and cooling towers.The objective of this study was to evaluate the formation of thrihalomethanes (THMs) and haloacetonitriles (HANs) and their cytotoxicity in algae solutions during free bromine disinfection.Disinfection by-products formation potential experiments were conducted using modelsolutions containing 7mg/L (as total organic carbon) Microcystis aeruginosa cells.Effects of free bromine dosage,pH and ammonia were investigated.The results showed that brominated disinfection by-products were the major products when free bromine was applied.The total THMs formed during bromination was much as that formed during chlorination,whereas HANs were elevated by using bromination instead of chlorination.Dibromoacetonitrice (C2H2NBr2) and bromoform (CHBr3) were the only detected species during free bromine disinfection.The production of C2H2NBr2 and CHBr3 increased with disinfectant dosage but decreased with dosing ammonia.CHBr3 increased with the pH changing from 5 to 9.However,C2H2NBr2 achieved the highest production at neutral pH,which was due to a joint effect of variation in hydrolysis rate and free bromine reactivity.The hydrolysis of C2H2NBr2 was basecatalytic and nearly unaffected by disinfectant.Finally,estimation of cytotoxicity of the disinfected algae solutions showed that HANs formation was responsible for the majority of toxicity.Considering its highest toxicity among the measured disinfection by-products,the elevated C2H2NBr2 should be considered when using bromine-related algaecide.

  6. Insight into Biochemical Characterization of Plant Sesquiterpene Synthases

    Science.gov (United States)

    Manczak, Tom; Simonsen, Henrik Toft

    2016-01-01

    A fast and reproducible protocol was established for enzymatic characterization of plant sesquiterpene synthases that can incorporate radioactivity in their products. The method utilizes the 96-well format in conjunction with cluster tubes and enables processing of >200 samples a day. Along with reduced reagent usage, it allows further reduction in the use of radioactive isotopes and flammable organic solvents. The sesquiterpene synthases previously characterized were expressed in yeast, and the plant-derived Thapsia garganica kunzeaol synthase TgTPS2 was tested in this method. KM for TgTPS2 was found to be 0.55 μM; the turnover number, kcat, was found to be 0.29 s−1, kcat for TgTPS2 is in agreement with that of terpene synthases of other plants, and kcat/KM was found to be 0.53 s−1 μM−1 for TgTPS2. The kinetic parameters were in agreement with previously published data. PMID:27721652

  7. Hologram QSAR Studies of Antiprotozoal Activities of Sesquiterpene Lactones

    Directory of Open Access Journals (Sweden)

    Gustavo H. G. Trossini

    2014-07-01

    Full Text Available Infectious diseases such as trypanosomiasis and leishmaniasis are considered neglected tropical diseases due the lack for many years of research and development into new drug treatments besides the high incidence of mortality and the lack of current safe and effective drug therapies. Natural products such as sesquiterpene lactones have shown activity against T. brucei and L. donovani, the parasites responsible for these neglected diseases. To evaluate structure activity relationships, HQSAR models were constructed to relate a series of 40 sesquiterpene lactones (STLs with activity against T. brucei, T. cruzi, L. donovani and P. falciparum and also with their cytotoxicity. All constructed models showed good internal (leave-one-out q2 values ranging from 0.637 to 0.775 and external validation coefficients (r2test values ranging from 0.653 to 0.944. From HQSAR contribution maps, several differences between the most and least potent compounds were found. The fragment contribution of PLS-generated models confirmed the results of previous QSAR studies that the presence of α,β-unsatured carbonyl groups is fundamental to biological activity. QSAR models for the activity of these compounds against T. cruzi, L. donovani and P. falciparum are reported here for the first time. The constructed HQSAR models are suitable to predict the activity of untested STLs.

  8. Hologram QSAR studies of antiprotozoal activities of sesquiterpene lactones.

    Science.gov (United States)

    Trossini, Gustavo H G; Maltarollo, Vinícius G; Schmidt, Thomas J

    2014-07-18

    Infectious diseases such as trypanosomiasis and leishmaniasis are considered neglected tropical diseases due the lack for many years of research and development into new drug treatments besides the high incidence of mortality and the lack of current safe and effective drug therapies. Natural products such as sesquiterpene lactones have shown activity against T. brucei and L. donovani, the parasites responsible for these neglected diseases. To evaluate structure activity relationships, HQSAR models were constructed to relate a series of 40 sesquiterpene lactones (STLs) with activity against T. brucei, T. cruzi, L. donovani and P. falciparum and also with their cytotoxicity. All constructed models showed good internal (leave-one-out q2 values ranging from 0.637 to 0.775) and external validation coefficients (r2test values ranging from 0.653 to 0.944). From HQSAR contribution maps, several differences between the most and least potent compounds were found. The fragment contribution of PLS-generated models confirmed the results of previous QSAR studies that the presence of α,β-unsatured carbonyl groups is fundamental to biological activity. QSAR models for the activity of these compounds against T. cruzi, L. donovani and P. falciparum are reported here for the first time. The constructed HQSAR models are suitable to predict the activity of untested STLs.

  9. In Vitro Antitumor Activity of Sesquiterpene Lactones from Lychnophora trichocarpha

    Directory of Open Access Journals (Sweden)

    D.A. Saúde-Guimarães

    2014-06-01

    Full Text Available The sesquiterpene lactones lychnopholide and eremantholide C were isolated from Lychnophora trichocarpha Spreng. (Asteraceae, which is a plant species native to the Brazilian Savannah or Cerrado and popularly known as arnica. Sesquiterpene lactones are known to present a variety of biological activities including antitumor activity. The present paper reports on the evaluation of the in vitro antitumor activity of lychnopholide and eremantholide C, in the National Cancer Institute, USA (NCI, USA, against a panel of 52 human tumor cell lines of major human tumors derived from nine cancer types. Lychnopholide disclosed significant activity against 30 cell lines of seven cancer types with IC100 (total growth concentration inhibition values between 0.41 µM and 2.82 µM. Eremantholide C showed significant activity against 30 cell lines of eight cancer types with IC100 values between 21.40 µM and 53.70 µM. Lychnopholide showed values of lethal concentration 50% (LC50 for 30 human tumor cell lines between 0.72 and 10.00 µM, whereas eremantholide C presented values of LC50 for 21 human tumor cell lines between 52.50 and 91.20 µM. Lychnopholide showed an interesting profile of antitumor activity. The α-methylene-γ-lactone present in the structure of lychnopholide, besides two α,β- unsaturated carbonyl groups, might be responsible for the better activity and higher cytotoxicity of this compound in relation to eremantholide C.

  10. New infrared spectroscopic database for bromine nitrate

    Science.gov (United States)

    Wagner, Georg; Birk, Manfred

    2016-08-01

    Fourier transform infrared measurements of bromine nitrate have been performed in the spectral region 675-1400 cm-1 at 0.014 cm-1 spectral resolution. Absorption cross sections were derived from 38 spectra covering the temperature range from 203 to 296 K and air pressure range from 0 to 190 mbar. For line-by-line analysis, further spectra were recorded at 0.00094 cm-1 spectral resolution at 223 and 293 K. The sample was synthesized from ClONO2 and Br2. Band strengths of the bands ν3 around 803 cm-1 and ν2 around 1286 cm-1 were determined from three pure BrONO2 measurements at different temperatures and pressures. Number densities in the absorption cell were derived from pressure measurements of the purified sample taking into account small amounts of impurities determined spectroscopically. Resulting band strengths are Sν3 = 2.872(52) × 10-17 cm2 molec-1 cm-1 and Sν2 = 3.63(15) × 10-17 cm2 molec-1 cm-1. Absorption cross sections of all measurements were scaled to these band strengths. Further data reduction was achieved with an interpolation scheme based on two-dimensional polynomials in ln(pressure) and temperature. The database is well-suited for remote-sensing application and should reduce the atmospheric bromine nitrate error budget substantially.

  11. Use of Bromine and Bromo-Organic Compounds in Organic Synthesis.

    Science.gov (United States)

    Saikia, Indranirekha; Borah, Arun Jyoti; Phukan, Prodeep

    2016-06-22

    Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

  12. Identification, functional characterization and developmental regulation of sesquiterpene synthases from sunflower capitate glandular trichomes

    Directory of Open Access Journals (Sweden)

    Ro Dae-Kyun

    2009-07-01

    Full Text Available Abstract Background Sesquiterpene lactones are characteristic metabolites of Asteraceae (or Compositae which often display potent bioactivities and are sequestered in specialized organs such as laticifers, resin ducts, and trichomes. For characterization of sunflower sesquiterpene synthases we employed a simple method to isolate pure trichomes from anther appendages which facilitated the identification of these genes and investigation of their enzymatic functions and expression patterns during trichome development. Results Glandular trichomes of sunflower (Helianthus annuus L. were isolated, and their RNA was extracted to investigate the initial steps of sesquiterpene lactone biosynthesis. Reverse transcription-PCR experiments led to the identification of three sesquiterpene synthases. By combination of in vitro and in vivo characterization of sesquiterpene synthase gene products in Escherichia coli and Saccharomyces cerevisiae, respectively, two enzymes were identified as germacrene A synthases, the key enzymes of sesquiterpene lactone biosynthesis. Due to the very low in vitro activity, the third enzyme was expressed in vivo in yeast as a thioredoxin-fusion protein for functional characterization. In in vivo assays, it was identified as a multiproduct enzyme with the volatile sesquiterpene hydrocarbon δ-cadinene as one of the two main products with α-muuorlene, β-caryophyllene, α-humulene and α-copaene as minor products. The second main compound remained unidentified. For expression studies, glandular trichomes from the anther appendages of sunflower florets were isolated in particular developmental stages from the pre- to the post-secretory phase. All three sesquiterpene synthases were solely upregulated during the biosynthetically active stages of the trichomes. Expression in different aerial plant parts coincided with occurrence and maturity of trichomes. Young roots with root hairs showed expression of the sesquiterpene synthase genes

  13. TG-MS investigation of brominated products from the degradation of brominated flame retardants in high-impact polystyrene.

    Science.gov (United States)

    Grause, Guido; Karakita, Daiki; Ishibashi, Jun; Kameda, Tomohito; Bhaskar, Thallada; Yoshioka, Toshiaki

    2011-10-01

    The thermal degradation of flame retardant containing high-impact polystyrene (HIPS-Br), one of the most commonly employed plastics in electric and electronic appliances, was examined by thermogravimetry coupled with mass spectroscopy (TG-MS) in order to understand the threat that is posed by the release of hazardous brominated compounds. The HIPS samples contained decabromodiphenylether (DPE) and decabromodibenzyl (DDB) as the flame retardants as well as Sb2O3 as the synergist. The largest number of brominated compounds was obtained in the presence of DPE and Sb2O3 and DDB without Sb2O3. From the degradation of DPE, brominated benzenes, phenols, diphenylethers, and dibenzofurans were identified, and from the degradation of DDB, brominated benzenes, dibenzyls, and phenanthrenes were formed. The interaction between the flame retardant and the polymer matrix resulted in α-bromoethylbenzene. The formation of brominated dibenzodioxins was not observed, probably, due to the low phenol concentration in the polymer melt. No other report has, to our knowledge, ever reported on the formation of brominated phenanthrenes from flame retardants. Because they share similar steric features, it may well be that brominated phenanthrenes are similar in their carcinogen and mutagen potential to dibenzofurans and dibenzodioxins. A plausible mechanism for the formation of the observed compounds is presented, and the role of the synergist is considered.

  14. Insight into Biochemical Characterization of Plant Sesquiterpene Synthases

    DEFF Research Database (Denmark)

    Manczak, Tom; Simonsen, Henrik Toft

    2016-01-01

    A fast and reproducible protocol was established for enzymatic characterization of plant sesquiterpene synthases that can incorporate radioactivity in their products. The method utilizes the 96-well format in conjunction with cluster tubes and enables processing of >200 samples a day. Along with ...... was found to be 0.55 μM; the turnover number, kcat, was found to be 0.29 s-1, kcat for TgTPS2 is in agreement with that of terpene synthases of other plants, and kcat/KM was found to be 0.53 s-1 μM-1 for TgTPS2. The kinetic parameters were in agreement with previously published data....

  15. ANTIBACTERIAL ACTIVITY OF GERMACRONE SESQUITERPENE FROM CURCUMA XANTHORRHIZA RHIZOMES

    Directory of Open Access Journals (Sweden)

    Hartiwi Diastuti

    2016-09-01

    Full Text Available The aim of this research was to isolate and indentify the terpenoid compound from Curcuma xanthorrhiza rhizomes and its antibacterial activity. Isolation was carried out by using vacuum liquid chromatography and centrifugal chromatography. The structure was determined by NMR spectroscopy (1H-NMR, 13C-NMR 1D and 2D, then compare with data from literatures. Antibacterial test was carried out by using microdillution methods and evaluated against eight bacteria. They are Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Enterobacter aerogenes, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysentriae and Vibrio cholerae. The result showed that the isolate was a white crystal which was indetified as germacron-type sesquiterpene. Germacron have highest activity againts P. aeruginosa, MIC 15.6 µg/mL and MBC 31.2 µg/mL.

  16. Solubility of the sesquiterpene alcohol patchoulol in supercritical carbon dioxide.

    Science.gov (United States)

    Hybertson, Brooks M

    2007-01-01

    The solubility of the sesquiterpene alcohol patchoulol in supercritical carbon dioxide was measured at P ranging from 10.0 MPa to 25.0 MPa and T of 40.0 and 50.0 °C using a simple microsampling type apparatus with a 100.5 µL sample loop to remove aliquots for off-line analysis. The system was first validated using vanillin with off-line spectrophotometric analysis, then utilized for patchoulol measurements with off-line GC-MS analysis. The measured solubility of patchoulol in supercritical CO(2) ranged from mole fractions of 0.43 × 10(-3) at 10.0 MPa and 50.0 °C to 9.45 × 10(-3) at 25.0 MPa and 40.0 °C.

  17. Sesquiterpenes of the geosmin-producing cyanobacterium Calothrix PCC 7507 and their toxicity to invertebrates.

    Science.gov (United States)

    Höckelmann, Claudia; Becher, Paul G; von Reuss, Stephan H; Jüttner, Friedrich

    2009-01-01

    The occurrence of sesquiterpenes was investigated with the geosmin-producing cyanobacterium Calothrix PCC 7507. The essential oil obtained by vacuum destillation was studied in more detail by GC-MS methods and superposition with authentic compounds. Geosmin was the dominating compound while the other sesquiterpenes were minor components. Sesquiterpenes that have not been described before in cyanobacteria were isodihydroagarofuran, eremophilone and 6,11-epoxyisodaucane. Closed-loop stripping analysis revealed that most of the sesquiterpenes were found in the biomass of Calothrix, while eremophilone was mainly observed in the medium of the axenic culture. Eremophilone showed acute toxicity (LC50) against Chironomus riparius (insecta) at 29 microM and against Thamnocephalus platyurus (crustacea) at 22 microM. The compound was not toxic for Plectus cirratus (nematoda). 6,11-Epoxyisodaucane and isodihydroagarofuran exhibited no toxicity to invertebrates when applied in concentrations up to 100 microM.

  18. Sesquiterpenes from the essential oil of Curcuma wenyujin and their inhibitory effects on nitric oxide production.

    Science.gov (United States)

    Xia, Guiyang; Zhou, Li; Ma, Jianghao; Wang, Ying; Ding, Liqin; Zhao, Feng; Chen, Lixia; Qiu, Feng

    2015-06-01

    Three new sesquiterpenes including a new elemane-type sesquiterpene, 5βH-elem-1,3,7,8-tetraen-8,12-olide (1), and two new carabrane-type sesquiterpenes, 7α,11-epoxy-6α-methoxy-carabrane-4,8-dione (2) and 8,11-epidioxy-8-hydroxy-4-oxo-6-carabren (3), together with eight known sesquiterpenes (4-11) were isolated from Curcuma wenyujin Y. H. Chen et C. Ling. Their structures were elucidated based on extensive spectroscopic analyses. A possible biogenetic scheme for the related compounds was postulated. All of the isolated compounds were tested for inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages. Meanwhile, preliminary structure-activity relationships for these compounds are discussed.

  19. SESQUITERPENE RICH VOLATILE SEED OIL OF TAGETES PATULA L. FROM NORTHWEST IRAN

    OpenAIRE

    M. B. Hassanpouraghdam; F Shekari; J. EMARAT-PARDAZ; SAFI SHALAMZARI, M.

    2011-01-01

    Hydrodistilled volatile seed oil composition of commonly growing ornamental Tagetes patula L. was analyzed for its constituents by GC/MS. Forty constituents were identified, comprising 94% of the total oil. Sesquiterpene hydrocarbons (52.7%) and oxygenated sesquiterpenes (15.8%) were the main subclasses of volatile oil components followed by monoterpene hydrocarbons (12.6%). The principle constituents of the volatile oil were (E)-caryophyllene (44.6%) caryophyllene oxide (14.8%), germacrene D...

  20. Identification of a novel sesquiterpene biosynthetic machinery involved in astellolide biosynthesis

    Science.gov (United States)

    Shinohara, Yasutomo; Takahashi, Shunji; Osada, Hiroyuki; Koyama, Yasuji

    2016-01-01

    Esterified drimane-type sesquiterpene lactones such as astellolides display various biological activities and are widely produced by plants and fungi. Given their low homology to known sesquiterpene cyclases, the genes responsible for their biosynthesis have not been uncovered yet. Here, we identified the astellolide gene cluster from Aspergillus oryzae and discovered a novel sesquiterpene biosynthetic machinery consisting of AstC, AstI, and AstK. All these enzymes are annotated as haloacid dehalogenase-like hydrolases, whereas AstC also contains a DxDTT motif conserved in class II diterpene cyclases. Based on enzyme reaction analyses, we found that AstC catalysed the protonation-initiated cyclisation of farnesyl pyrophosphate into drimanyl pyrophosphate. This was successively dephosphorylated by AstI and AstK to produce drim-8-ene-11-ol. Moreover, we also identified and characterised a unique non-ribosomal peptide synthetase, AstA, responsible for esterifying aryl acids to drimane-type sesquiterpene lactones. In this study, we highlight a new biosynthetic route for producing sesquiterpene and its esterified derivative. Our findings shed light on the identification of novel sesquiterpenes via genome mining. PMID:27628599

  1. Sesquiterpenes from the Brazilian Red Alga Laurencia dendroidea J. Agardh

    Directory of Open Access Journals (Sweden)

    Fernanda Lacerda da Silva Machado

    2014-03-01

    Full Text Available Two new chamigrane sesquiterpenes 1–2 and three known compounds 3–5 were isolated from a lipophilic extract of the red alga Laurencia dendroidea collected from the Southeastern Brazilian coast. Dendroidone (1 and dendroidiol (2 were isolated from samples collected at Biscaia Inlet, Angra dos Reis, Rio de Janeiro and at Manguinhos Beach, Serra, Espírito Santo, respectively. Debromoelatol (3, obtusane (4 and (1S*,2S*,3S*,5S*,8S*,9S*-2,3,5,9-tetramethyltricyclo[6.3.0.01.5]undecan-2-ol (5 were obtained from specimens collected at Vermelha Beach, Parati, Rio de Janeiro. The structures of new compounds were elucidated by extensive NMR (1H-, 13C-, COSY, HSQC, HMBC and NOESY and high resolution mass spectrometry analysis. Additionally, the absolute configuration of compound 2 was assigned by X-ray analysis. Full spectroscopic data is described for the first time for compound 3. Anti-inflammatory and antimycobacterial activities of compounds 2–5 were evaluated. Compounds 3–5 inhibited the release of inflammatory mediator NO while TNF-α levels were only affected by 3. All compounds tested displayed moderate antimycobacterial action.

  2. In Vitro Antiplasmodial Activity of Sesquiterpene Lactones from Ambrosia tenuifolia

    Directory of Open Access Journals (Sweden)

    V. Sülsen

    2011-01-01

    Full Text Available The in vitro antiplasmodial activity of Ambrosia tenuifolia organic extract and its isolated sesquiterpene lactones, psilostachyin and peruvin, has been evaluated against Plasmodium falciparum F32 and W2 strains. The cytotoxicity of both compounds was determined on lymphoid cells, and their corresponding selectivity indexes (SIs were calculated. Peruvin was the most active compound on F32 strain of P. falciparum with a 50% inhibitory concentration value (IC50 of 0.3 μg/mL (1.1 μM whereas psilostachyin showed activity on both strains (IC50 = 0.6 (2.1 μM and 1.8 μg/mL (6.4 μM. Fifty percent cytotoxic concentration (CC50 values (48 h were 6.8 μg/mL (24.3 μM and 10.0 μg/mL (37.9 μM for psilostachyin and peruvin, respectively.

  3. Sesquiterpenes from the Brazilian red alga Laurencia dendroidea J. Agardh.

    Science.gov (United States)

    da Silva Machado, Fernanda Lacerda; Ventura, Thatiana Lopes Biá; Gestinari, Lísia Mônica de Souza; Cassano, Valéria; Resende, Jackson Antônio Lamounier Camargos; Kaiser, Carlos Roland; Lasunskaia, Elena B; Muzitano, Michelle Frazão; Soares, Angélica Ribeiro

    2014-03-17

    Two new chamigrane sesquiterpenes 1-2 and three known compounds 3-5 were isolated from a lipophilic extract of the red alga Laurencia dendroidea collected from the Southeastern Brazilian coast. Dendroidone (1) and dendroidiol (2) were isolated from samples collected at Biscaia Inlet, Angra dos Reis, Rio de Janeiro and at Manguinhos Beach, Serra, Espírito Santo, respectively. Debromoelatol (3), obtusane (4) and (1S*,2S*,3S*,5S*,8S*,9S*)-2,3,5,9-tetramethyltricyclo[6.3.0.0¹·⁵]undecan-2-ol (5) were obtained from specimens collected at Vermelha Beach, Parati, Rio de Janeiro. The structures of new compounds were elucidated by extensive NMR (¹H-, ¹³C-, COSY, HSQC, HMBC and NOESY) and high resolution mass spectrometry analysis. Additionally, the absolute configuration of compound 2 was assigned by X-ray analysis. Full spectroscopic data is described for the first time for compound 3. Anti-inflammatory and antimycobacterial activities of compounds 2-5 were evaluated. Compounds 3-5 inhibited the release of inflammatory mediator NO while TNF-α levels were only affected by 3. All compounds tested displayed moderate antimycobacterial action.

  4. Seasonal variation of mono- and sesquiterpene emission rates of Scots pine

    Directory of Open Access Journals (Sweden)

    H. Hakola

    2006-01-01

    Full Text Available The seasonal variation of mono-and sesquiterpene emission rates of Scots pine was measured from April to October in 2004. The emission rates were measured daily in the afternoons with the exception of weekends. Emissions were measured from two branches; one of them was debudded in May (branch A, while the other was allowed to grow new needles (branch B. The monoterpene emission pattern remained almost constant throughout the measurement period, Δ3-carene being the dominant monoterpene (50-70% of the VOC emission. The standard monoterpene emission potential (30°C was highest during early summer in June (the average of the two branches 1.35 µg g-1h-1 and lowest during early autumn in September (the average of the two branches 0.20 µg g-1h-1. The monoterpene emission potential of branch A remained low also during October, whereas the emission potential of branch B was very high in October. The sesquiterpenes were mainly emitted during mid summer, the dominant sesquiterpene being β-caryophyllene. Branch A had a higher sesquiterpene emission potential than branch B and the emission maximum occurred concomitant with the high concentration of airborne pathogen spores suggesting a potential defensive role of the sesquiterpene emissions. The sesquiterpene emissions were well correlated with linalool and 1,8-cineol emissions, but not with monoterpenes. Sesquiterpene and 1,8-cineol emissions were equally well described by the temperature dependent and the temperature and light dependent algorithms. This is due to the saturation of the light algorithm as the measurements were always conducted during high light conditions.

  5. Bromine pretreated chitosan for adsorption of lead (II) from water

    Indian Academy of Sciences (India)

    Rajendra Dongre; Minakshi Thakur; Dinesh Ghugal; Jostna Meshram

    2012-10-01

    Pollution by heavy metals like lead (II) is responsible for health hazards and environmental degradation. Adsorption is a prevalent method applied for removal of heavy metal pollutants from water. This study explored adsorption performances of 30% bromine pretreated chitosan for lead (II) abatement from water. Bromine pretreatment alters porosity and specific surface area of chitosan by means of physicochemical interaction with cationic sites of chitosan skeleton, besides imparting anionic alteration at amino linkages of chitosan, to remove lead (II) by chemical interactions on superfluous active sites as characterized by FTIR, SEM, DTA and elemental analysis. Lead adsorptions were studied in batch mode by varying parameters viz. pH, bromine loading, sorbent dosage, initial lead concentration, contact time and temperature. The adsorption equilibrium data was well fitted to Freundlich isotherm and maximum sorption capacity of 30% bromine pretreated chitosan sorbent was 1.755 g/kg with 85–90% lead removal efficiency. Though cost and applicability of sorbent is unproven, yet contrast to raw chitosan derivatives, activated carbons and some resins, 30% bromine pretreated chitosan endow benign and efficient lead abatement technique.

  6. Fate of higher brominated PBDEs in lactating cows.

    Science.gov (United States)

    Kierkegaard, Amelie; Asplund, Lillemor; de Wit, Cynthia A; McLachlan, Michael S; Thomas, Gareth O; Sweetman, Andrew J; Jones, Kevin C

    2007-01-15

    Dietary intake studies of lower brominated diphenyl ethers (BDEs) have shown that fish and animal products are important vectors of human exposure, but almost no data exist for higher brominated BDEs. Therefore, the fate of hepta- to decaBDEs was studied in lactating cows exposed to a naturally contaminated diet by analyzing feed, feces, and milk samples from a previous mass balance study of PCB. Tissue distribution was studied in one cow slaughtered after the experiment. BDE-209 was the dominant congener in feed, organs, adipose tissues, and feces, but not in milk. In contrast to PCBs and lower brominated BDEs, concentrations of hepta- to decaBDEs in adipose tissue were 9-80 times higher than in milk fat and the difference increased with degree of bromination/log K(OW). The congener profiles in adipose tissue and feed differed; BDE-207, BDE-196, BDE-197, and BDE-182 accumulated to a surprisingly greater extent in the fat compared to their isomers, suggesting metabolic debromination of BDE-209 to these BDEs. The results indicate that meat rather than dairy product consumption may be an important human exposure route to higher brominated BDEs.

  7. Environmental monitoring of brominated flame retardants

    Science.gov (United States)

    Vagula, Mary C.; Kubeldis, Nathan; Nelatury, Charles F.

    2011-06-01

    Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition and combustion processes. Because of their immense ability to retard fire and save life and property, they have been extensively used in many products such as TVs, computers, foam, plastics etc. The five major classes of BFRs are tetrabromobisphenol-A (TBBPA), hexabromocyclododecane (HBCD), pentabromodiphenyl ether, octabromodiphenyl ether, and decabromodiphenyl ether. The last three are also commonly called PBDEs. BDE-85 and BDE-209 are the two prominent congeners of PBDEs and this study reports the adverse effects of these congeners in rodents. Exposure of rat sciatic nerves to 5 μg/mL and 20 μg/mL of BDE-85 and BDE-209 respectively lead to significant, concentration dependent reduction in nerve conduction function. Glucose absorption in the rat intestinal segments exposed to 5 μg/mL of BDE-85 and BDE-209 was significantly reduced for both the compounds tested. Lastly, mice when exposed to 0.25 mg/kg body weight for four days showed a disruption in oxidant and antioxidant equilibrium. The tissues namely liver and brain have shown increase in the levels of lipid hydroperoxides indicating oxidative stress. Moreover, all the protective enzymes namely superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase, and glutathione S transferase (GST) have shown tissue specific alterations indicating the induction of damaging oxidative stress and setting in of lipid peroxidation in exposed animals. The results indicate monitoring of PBDEs in the environment is essential because levels as low as 5 μg/mL and 0.25 mg/kg body weight were able to cause damage to the functions of rodents.

  8. The geochemistry of stable chlorine and bromine isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Eggenkamp, Hans [Onderzock and Beleving, Bussum (Netherlands)

    2014-11-01

    First book solely dedicated to the geochemistry of chlorine and bromine isotopes. Detailed description of analytical techniques, including their advantages and disadvantages. Indication of research fields where measurement of these isotopes is especially useful. This book provides detailed information on the history, analysis and applications of chlorine and bromine isotope geochemistry. Chlorine and bromine are geochemically unique as they prefer to exist as single charged negative ions. For this reason isotope fractionation reflects mostly processes that are not related to changes in the redox state and this fractionation is generally modest. The book will describe the processes that are most easily detected using these isotopes. Also isotope variations, and processes that cause them, measured in oxidised species such as perchlorates and in organic molecules will be described in this book.

  9. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  10. An Efficient and Facile Methodology for Bromination of Pyrimidine and Purine Nucleosides with Sodium Monobromoisocyanurate (SMBI

    Directory of Open Access Journals (Sweden)

    Roger Stromberg

    2013-10-01

    Full Text Available An efficient and facile strategy has been developed for bromination of nucleosides using sodium monobromoisocyanurate (SMBI. Our methodology demonstrates bromination at the C-5 position of pyrimidine nucleosides and the C-8 position of purine nucleosides. Unprotected and also several protected nucleosides were brominated in moderate to high yields following this procedure.

  11. Tricyclic sesquiterpene copaene prevents H2O2-induced neurotoxicity

    Directory of Open Access Journals (Sweden)

    Hasan Turkez

    2014-02-01

    Full Text Available Aim: Copaene (COP, a tricyclic sesquiterpene, is present in several essential oils of medicinal and aromatic plants and has antioxidant and anticarcinogenic features. But, very little information is known about the effects of COP on oxidative stress induced neurotoxicity. Method: We used hydrogen peroxide (H2O2 exposure for 6 h to model oxidative stress. Therefore, this experimental design allowed us to explore the neuroprotective potential of COP in H2O2-induced toxicity in rat cerebral cortex cell cultures for the first time. For this purpose, methyl thiazolyl tetrazolium (MTT and lactate dehydrogenase (LDH release assays were carried out to evaluate cytotoxicity. Total antioxidant capacity (TAC and total oxidative stress (TOS parameters were used to evaluate oxidative changes. In addition to determining of 8-hydroxy-2-deoxyguanosine (8-OH-dG levels, the single cell gel electrophoresis (SCGE or comet assay was also performed for measuring the resistance of neuronal DNA to H2O2-induced challenge. Result: The results of this study showed that survival and TAC levels of the cells decreased, while TOS, 8-OH-dG levels and the mean values of the total scores of cells showing DNA damage increased in the H2O2 alone treated cultures. But pre-treatment of COP suppressed the cytotoxicity, genotoxicity and oxidative stress which were increased by H2O2. Conclusion: It is proposed that COP as a natural product with an antioxidant capacity in mitigating oxidative injuries in the field of neurodegenerative diseases. [J Intercult Ethnopharmacol 2014; 3(1.000: 21-28

  12. Sesquiterpene and Acetogenin Derivatives from the Marine Red Alga Laurencia okamurai

    Directory of Open Access Journals (Sweden)

    Bin-Gui Wang

    2012-12-01

    Full Text Available In addition to 13 known compounds, four new bisabolane sesquiterpenes, okamurenes A–D (1–4, a new chamigrane derivative, okamurene E (5, and a new C12-acetogenin, okamuragenin (6, were isolated from the marine red alga Laurencia okamurai. The structures of these compounds were determined through detailed spectroscopic analyses. Of these, okamurenes A and B (1 and 2 are the first examples of bromobisabolane sesquiterpenes possessing a phenyl moiety among Laurencia-derived sesquiterpenes, while okamuragenin (6 was the first acetogenin aldehyde possessing a C12-carbon skeleton. Each of the isolated compounds was evaluated for the brine shrimp (Artemia salina lethal assay and 7-hydroxylaurene displayed potent lethality with LD50 1.8 μM.

  13. 3-Ishwarone and 3-Ishwarol, rare sesquiterpenes in essential oil from leaves of Peperomia oreophila Hensch

    Energy Technology Data Exchange (ETDEWEB)

    Lago, Joao Henrique G. [Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil). Centro de Ciencias e Humanidades]. E-mail: joaolago@iq.usp.br; Oliveira, Alberto de; Kato, Massuo J. [Sao Paulo Univ., SP (Brazil). Inst. de Quimica; Guimaraes, Elsie F. [Jardim Botanico do Rio de Janeiro, Rio de Janeiro, RJ (Brazil). Instituto de Pesquisas

    2007-07-01

    The essential oil from Peperomia oreophila leaves (Piperaceae) was submitted to fractionation in silica gel column. This separation procedure yielded a fraction composed of a hydrocarbon sesquiterpene mixture which was identified as {beta}-elemene, {alpha}-ylangene, {alpha}-guaiene and {beta}-selinene. Besides, spathulenol and two sesquiterpenes with the rare ishwarane skeleton: 3-ishwarol and 3-ishwarone were also identified. 3-ishwarone was the major component of the crude oil (78% weight). Since the alcohol obtained was not sufficient to allow a complete structural determination, the original ketone was reduced to 3-ishwarol in order to give additional quantities. After the two sesquiterpenes purification, they were characterized by spectrometric techniques ({sup 1}H-{sup 1}H COSY, HMQC, HMBC and NOESY). (author)

  14. Improved herbivore resistance in cultivated tomato with the sesquiterpene biosynthetic pathway from a wild relative.

    Science.gov (United States)

    Bleeker, Petra M; Mirabella, Rossana; Diergaarde, Paul J; VanDoorn, Arjen; Tissier, Alain; Kant, Merijn R; Prins, Marcel; de Vos, Martin; Haring, Michel A; Schuurink, Robert C

    2012-12-04

    Tomato breeding has been tremendously efficient in increasing fruit quality and quantity but did not focus on improving herbivore resistance. The biosynthetic pathway for the production of 7-epizingiberene in a wild tomato was introduced into a cultivated greenhouse variety with the aim to obtain herbivore resistance. 7-Epizingiberene is a specific sesquiterpene with toxic and repellent properties that is produced and stored in glandular trichomes. We identified 7-epizingiberene synthase (ShZIS) that belongs to a new class of sesquiterpene synthases, exclusively using Z-Z-farnesyl-diphosphate (zFPP) in plastids, probably arisen through neo-functionalization of a common ancestor. Expression of the ShZIS and zFPP synthases in the glandular trichomes of cultivated tomato resulted in the production of 7-epizingiberene. These tomatoes gained resistance to several herbivores that are pests of tomato. Hence, introduction of this sesquiterpene biosynthetic pathway into cultivated tomatoes resulted in improved herbivore resistance.

  15. Sensing and inactivation of Bacillus anthracis Sterne by polymer-bromine complexes.

    Science.gov (United States)

    D'Angelo, Paola A; Bromberg, Lev; Hatton, T Alan; Wilusz, Eugene

    2016-08-01

    We report on the performance of brominated poly(N-vinylpyrrolidone) (PVP-Br), brominated poly(ethylene glycol) (PEG-Br), and brominated poly(allylamine-co-4-aminopyridine) (PAAm-APy-Br) for their ability to decontaminate Bacillus anthracis Sterne spores in solution while also allowing for the sensing of the spores. The polymers were brominated by bromine using carbon tetrachloride or potassium tribromide as solvents, with bromine loadings ranging from 1.6 to 4.2 mEq/g of polymer. B. anthracis Sterne spores were exposed to increasing concentrations of brominated polymers for 5 min, while the kinetics of the sporicidal activity was assessed. All brominated polymers demonstrated spore log-kills of 8 within 5 min of exposure at 12 mg/mL aqueous polymer concentration. Sensing of spores was accomplished by measuring the release of dipicolinic acid (DPA) from the spore using time-resolved fluorescence. Parent, non-brominated polymers did not cause any release of DPA and the spores remained viable. In contrast, spores exposed to the brominated polymers were inactivated and the release of DPA was observed within minutes of exposure. Also, this release of DPA continued for a long time after spore inactivation as in a controlled release process. The DPA release was more pronounced for spores exposed to brominated PVP and brominated PEG-8000 compared to brominated PAAm-APy and brominated PEG-400. Using time-resolved fluorescence, we detected as low as 2500 B. anthracis spores, with PEG-8000 being more sensitive to low spore numbers. Our results suggest that the brominated polymers may be used effectively as decontamination agents against bacterial spores while also providing the sensing capability.

  16. Non-natural elemane as the "stepping stone" for the synthesis of germacrane and guaiane sesquiterpenes.

    Science.gov (United States)

    Anagnostaki, Elissavet E; Zografos, Alexandros L

    2013-01-01

    The synthesis of hydroxyelemane 5 from (R)-carvone and its utilization as a common synthetic scaffold to produce structurally diverse germacrane and guaiane sesquiterpenes are described. A highly enantio- and stereoselective biomimetic tandem oxy-Cope/ene rearrangement was used as the key reaction to access the 10-membered macrocyclic core of germacranes and the condensed 5-7 carbocycles of guaiane sesquiterpenes. Additionally, reactions of furanoguaianes under acidic or oxidizing reagents have been investigated, and preliminary results of these conversions are presented.

  17. Sesquiterpene coumarins from Ferula fukanensis and their pro-inflammatory cytokine gene expression inhibitory effects.

    Science.gov (United States)

    Motai, Tsunetake; Daikonya, Akihiro; Kitanaka, Susumu

    2013-01-01

    Six new sesquiterpene coumarin derivatives, fukanefuromarin H-M (1-6), were isolated from an 80% aqueous methanol extract of the roots of Ferula fukanensis. The structures were elucidated on the basis of spectroscopic evidence, particularly heteronuclear multiple-bond connectivity (HMBC) and high-resolution MS. The sesquiterpene coumarin derivatives inhibited nitric oxide (NO) and inducible NO synthase (iNOS), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) gene expression in a murine macrophage-like cell line (RAW264.7), which was activated by lipopolysaccharide (LPS) and recombinant mouse interferon-γ (IFN-γ).

  18. Two new sesquiterpene derivatives from the Tunisian endemic Ferula tunetana Pom.

    Science.gov (United States)

    Jabrane, Aymen; Ben Jannet, Hichem; Mighri, Zine; Mirjolet, Jean-François; Duchamp, Olivier; Harzallah-Skhiri, Féthia; Lacaille-Dubois, Marie-Aleth

    2010-02-01

    A new sesquiterpene ester, tunetanin A (1), a new sesquiterpene coumarin, tunetacoumarin A (2), together with eight known compounds, i.e., coladin (3), coladonin (4), isosmarcandin (5), 13-hydroxyfeselol (6), umbelliprenin (7) propiophenone (8), beta-sitosterol (9), and stigmasterol (10), were isolated from the roots of Ferula tunetana. Their structures were elucidated on the basis of extensive spectroscopic methods, including 1D- and 2D-NMR experiments and MS analysis, as well as by comparison with published data. The cytotoxicity of compounds 1-7 towards two human colon cancer cell lines, HT-29 and HCT 116, was evaluated. Compounds 3, 4, and 6 showed weak cytotoxic activities.

  19. Neolignans and sesquiterpenes from leaves and embryogenic cultures of Ocotea Catharinensis (Lauraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Funasaki, Mariko; Kato, Massuo J. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica; Lordello, Ana Luisa L. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica; Viana, Ana Maria [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Centro de Ciencias Biologicas. Dept. de Botanica; Santa-Catarina, Claudete; Floh, Eny I.S. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Biociencias; Yoshida, Massayoshi [Centro de Biotecnologia da Amazonia, Manaus, AM (Brazil)

    2009-07-01

    The extracts from leaves of Ocotea catharinensis Mez (Lauraceae) were found to contain fourteen neolignans and two sesquiterpenes: nine benzofuran types (including three new compounds 1e, 2f and 4b), one new seco-benzofuran type (3b), two bicyclo[3.2.1]octane types (including the new compound 5c), two new dimers of bicyclo[3.2.1]octane type (7a and 7b) and two sesquiterpenes (including a new humulanol 9). In addition, seven neolignans were also showed to occur in somatic embryos of O. catharinensis including one new bicyclo[3.2.1]octane type (4a). (author)

  20. A new eremophilane-type sesquiterpene from the phytopatogen fungus Lasiodiplodia theobromae (Sphaeropsidaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Fatima M.; Oliveira, Maria da Conceicao F. de; Arriaga, Angela M.C.; Lemos, Telma L.G.; Andrade-Neto, Manoel; Mattos, Marcos C. de [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica]. E-mail: mcfo@ufc.br; Mafezoli, Jair [Universidade de Fortaleza, CE (Brazil). Curso de Farmacia; Viana, Francisco M.P.; Ferreira, Viviane M. [EMBRAPA Agroindustria Tropical, Fortaleza, CE (Brazil). Lab. de Fitopatologia; Rodrigues-Filho, Edson; Ferreira, Antonio G. [Universidade Federal de Sa Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2008-07-01

    The phytopatogenic fungus Lasiodiplodia theobromae, isolated from guava, was cultivated in rice for 32 days at room temperature. Extraction with CH{sub 2}Cl{sub 2}:MeOH (3:7), followed by chromatography fractionation of the extract provided ergosterol. From the fungus culture in Czapeck medium for 40 days at room temperature, were isolated isocoumarin cis-4-hydroxymeleine and an eremophilane-type sesquiterpene. The latter compound is being reported for the first time in the literature. Also, this is the first time that an eremophilane sesquiterpene is described for Lasiodiplodia genus. (author)

  1. Brominated Dioxins: Little-Known New Health Hazards - A Review

    Directory of Open Access Journals (Sweden)

    Piskorska-Pliszczyńska Jadwiga

    2014-10-01

    Full Text Available This article reviews the present state of the science concerning the polybrominated dibenzo-p-dioxins (PBDDs and dibenzofurans (PBDFs. Everywhere in the world people are exposed to anthropogenic origin chemicals. Some of them are long-lived organic compounds, which persist over the years in the environment. Persistent organic pollutants, such as organohalogen compounds, accumulate in environmental and biological compartments and have adverse effects on the health of humans and animals. Little is known about the brominated and mixed chloro/bromo dioxin and furans. Existing literature suggests that brominated dioxins and furans have similar toxicity profiles to their chlorinated analogues. The exposure data are extremely limited, showing a major data gap in estimating the potential environmental and health risk of these chemicals. The rapid increase in the use of brominated flame retardants (the main source of these pollutants has raised the level of concern over environmental and health damage from brominated dioxins and furans. It is likely that human as well as wildlife exposure to these contaminants will increase with their greater use. The findings reported here present strong evidence of the PBDDs and PBDFs as an emerging new class of contaminants.

  2. A Sternheimer-like response property of the bromine molecule

    Science.gov (United States)

    Fowler, P. W.; Peebles, S. A.; Legon, A. C.

    The generalised polarisability describing the response to an applied field of the electric field gradient at a nucleus in Br2 is calculated ab initio. A value of 110.55 a-10 is found at the self-consistent -field level. This is about half the value derived by modelling the measured nuclear quadrupole coupling constants of theammonia-bromine complex.

  3. Bromine measurements in ozone depleted air over the Arctic Ocean

    Directory of Open Access Journals (Sweden)

    J. A. Neuman

    2010-07-01

    Full Text Available In situ measurements of ozone, photochemically active bromine compounds, and other trace gases over the Arctic Ocean in April 2008 are used to examine the chemistry and geographical extent of ozone depletion in the arctic marine boundary layer (MBL. Data were obtained from the NOAA WP-3D aircraft during the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC study and the NASA DC-8 aircraft during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS study. Fast (1 s and sensitive (detection limits at the low pptv level measurements of BrCl and BrO were obtained from three different chemical ionization mass spectrometer (CIMS instruments, and soluble bromide was measured with a mist chamber. The CIMS instruments also detected Br2. Subsequent laboratory studies showed that HOBr rapidly converts to Br2 on the Teflon instrument inlets. This detected Br2 is identified as active bromine and represents a lower limit of the sum HOBr + Br2. The measured active bromine is shown to likely be HOBr during daytime flights in the arctic. In the MBL over the Arctic Ocean, soluble bromide and active bromine were consistently elevated and ozone was depleted. Ozone depletion and active bromine enhancement were confined to the MBL that was capped by a temperature inversion at 200–500 m altitude. In ozone-depleted air, BrO rarely exceeded 10 pptv and was always substantially lower than soluble bromide that was as high as 40 pptv. BrCl was rarely enhanced above the 2 pptv detection limit, either in the MBL, over Alaska, or in the arctic free troposphere.

  4. Hirsutane Sesquiterpenes from Cultures of the Basidiomycete Marasmiellus sp. BCC 22389.

    Science.gov (United States)

    Isaka, Masahiko; Palasarn, Somporn; Sappan, Malipan; Supothina, Sumalee; Boonpratuang, Thitiya

    2016-10-01

    Two new hirsutane sesquiterpenes, marasmiellins A (1) and B (2), were isolated from cultures of the basidiomycete Marasmiellus sp. BCC 22389. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The absolute configuration of marasmiellin B was determined by application of the modified Mosher's method.

  5. Sesquiterpene coumarins from the roots of Ferula sinkiangensis and Ferula teterrima.

    Science.gov (United States)

    Yang, Jun-Rong; An, Zheng; Li, Zhi-Hong; Jing, Song; Qina, Hai-Lin

    2006-11-01

    Three new natural sesquiterpene coumarins, isofeterin (1), lehmannolol (3), sinkianone (4), and one known compound, lehmannolone (2), were isolated from the roots of Ferula teterrima and Ferula sinkiangensis. Their chemical structures were established on the basis of spectroscopic analysis, including X-ray crystallography and CD spectrum measurements for determining the absolute configuration of compound 2.

  6. Ermophilane sesquiterpenes from Hawaiian endophytic fungus Chaetoconis sp.FT087

    Science.gov (United States)

    Seven sesquiterpene derivatives, including chaetopenoids A–F and dendryphiellin A1, and 6-methyl-(2E,4E, 6S) octadienoic acid were isolated from the culture broth of Chaetoconis sp. FT087. Their structures were determined through the analysis of HRMS and NMR spectroscopic data. The absolute configur...

  7. Hirsutane Sesquiterpenes from Cultures of the Basidiomycete Marasmiellus sp. BCC 22389

    Directory of Open Access Journals (Sweden)

    Masahiko Isaka

    2016-08-01

    Full Text Available Abstract Two new hirsutane sesquiterpenes, marasmiellins A (1 and B (2, were isolated from cultures of the basidiomycete Marasmiellus sp. BCC 22389. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. The absolute configuration of marasmiellin B was determined by application of the modified Mosher’s method. Graphical Abstract

  8. Routine patch testing with the sesquiterpene lactone mix in Europe: a 2-year experience

    DEFF Research Database (Denmark)

    Paulsen, E; Andersen, Klaus Ejner; Brandão, F M

    1999-01-01

    To test the screening value of the sesquiterpene lactone (SL) mix in Europe today and describe epidemiological and clinical features of Compositae-sensitive patients, the SL mix 0.1% pet. was included in the standard patch test series in 11 European clinics. 10,695 patients were tested, and 106 (...

  9. Two new sesquiterpene glycosides isolated from the fresh needles of Pinus massoniana Lamb.

    Science.gov (United States)

    Xiao, Yun-Chuan; Ye, Liang; Zhao, Man-Xi; Yan, Cui-Qi; Wang, Wei; Huang, Quan-Shu; Liang, Kai; Meng, Bao-Hua; Ke, Xiao

    2017-02-01

    Two new sesquiterpene glycosides, namely massonside A (1) and massonside B (2), were isolated from the n-Bu extract of the fresh needles of Pinus massoniana Lamb. Their structures were established by 1D, 2D nuclear magnetic resonance and high-resolution mass spectrometry. Their biological activities were profiled by the anti-HBV and anti-HCV assays.

  10. Mountain birch – potentially large source of sesquiterpenes into high latitude atmosphere

    Directory of Open Access Journals (Sweden)

    S. Haapanala

    2009-06-01

    Full Text Available Emissions of volatile organic compounds (VOCs from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up majority of the tree biomass in Scandinavian high latitudes, area subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of a branch from four individual trees were measured in June–August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of sesquiterpene emission changed dramatically between the years. For example, the average α-farnesene emission in 2006 was almost 2000 ng gdw−1 h−1 while in 2007 the emission of α-farnesene was negligible. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of α-farnesene, and the effect may last several years.

  11. Mountain birch – potentially large source of sesquiterpenes into high latitude atmosphere

    Directory of Open Access Journals (Sweden)

    A. Arneth

    2009-11-01

    Full Text Available Emissions of volatile organic compounds (VOCs from mountain birches were measured in Abisko, northern Sweden. Mountain birches make up the majority of the tree biomass in Scandinavian high latitudes, a region subject to significant climate warming. The measurements were carried out in two growing seasons. The emissions of four branches, each from a different individual tree, were measured in June–August 2006 and one of them again in July 2007. The measurements were conducted using a dynamic flow through chamber covered with Teflon film. The studied mountain birches were found to emit substantial amounts of linalool, monoterpenes and sesquiterpenes. The monoterpene emission was dominated by sabinene. The magnitude and composition of the sesquiterpene emission changed dramatically between the years. For example, the average α-farnesene emission potential in 2006 was almost 2600 ng gdw−1 h−1 (3.5 pmol gdw−1 s−1 while in 2007 α-farnesene was not detected at all. Also the emissions of other sesquiterpenes decreased in 2007 to a fraction of that in 2006. One possible explanation for the change in emissions is the herbivory damage that occurred in the area in 2004. Herbivory is known to enhance the emissions of sesquiterpenes, especially those of α-farnesene, and the effect may last for several years.

  12. Isolation and Identification of a New Antifungal Sesquiterpene Lactone from Inula viscosa.

    Science.gov (United States)

    Maoz, M; Kashman, Y; Neeman, I

    1999-04-01

    A new sesquiterpene - tayunin - has been isolated and purified from powdered leaves of INULA VISCOSA (L.) Ait. The chemical structure was determined by 1D and 2D NMR analysis, and IR and MS. Tayunin inhibits the growth of MICROSPORUM CANIS at a concentration of 10 microg/ml and TRICHOPHYTON RUBRUM at 50 microg/ml(MIC).

  13. Synthesis of (E,E)-Germacrane Sesquiterpene Alcohols via Enolate-Assisted 1,4-Fragmentation

    NARCIS (Netherlands)

    Minnaard, Adriaan J.; Wijnberg, Joannes B.P.A.; Groot, Aede de

    1997-01-01

    An efficient method has been developed for the synthesis of (E,E)-germacrane sesquiterpene alcohols. The key step in these syntheses involves the enolate-assisted 1,4-fragmentation of properly functionalized perhydro-1-naphthalenecarboxaldehydes with 1 equiv of sodium tert-amylate as base, to give t

  14. Mode of Action of the Sesquiterpene Lactones Psilostachyin and Psilostachyin C on Trypanosoma cruzi.

    Science.gov (United States)

    Sülsen, Valeria P; Puente, Vanesa; Papademetrio, Daniela; Batlle, Alcira; Martino, Virginia S; Frank, Fernanda M; Lombardo, María E

    2016-01-01

    Trypanosoma cruzi is the causative agent of Chagas' disease, which is a major endemic disease in Latin America and is recognized by the WHO as one of the 17 neglected tropical diseases in the world. Psilostachyin and psilostachyin C, two sesquiterpene lactones isolated from Ambrosia spp., have been demonstrated to have trypanocidal activity. Considering both the potential therapeutic targets present in the parasite, and the several mechanisms of action proposed for sesquiterpene lactones, the aim of this work was to characterize the mode of action of psilostachyin and psilostachyin C on Trypanosoma cruzi and to identify the possible targets for these molecules. Psilostachyin and psilostachyin C were isolated from Ambrosia tenuifolia and Ambrosia scabra, respectively. Interaction of sesquiterpene lactones with hemin, the induction of oxidative stress, the inhibition of cruzipain and trypanothione reductase and their ability to inhibit sterol biosynthesis were evaluated. The induction of cell death by apoptosis was also evaluated by analyzing phosphatidylserine exposure detected using annexin-V/propidium iodide, decreased mitochondrial membrane potential, assessed with Rhodamine 123 and nuclear DNA fragmentation evaluated by the TUNEL assay. Both STLs were capable of interacting with hemin. Psilostachyin increased about 5 times the generation of reactive oxygen species in Trypanosoma cruzi after a 4h treatment, unlike psilostachyin C which induced an increase in reactive oxygen species levels of only 1.5 times. Only psilostachyin C was able to inhibit the biosynthesis of ergosterol, causing an accumulation of squalene. Both sesquiterpene lactones induced parasite death by apoptosis. Upon evaluating the combination of both compounds, and additive trypanocidal effect was observed. Despite their structural similarity, both sesquiterpene lactones exerted their anti-T. cruzi activity through interaction with different targets. Psilostachyin accomplished its antiparasitic

  15. Mode of Action of the Sesquiterpene Lactones Psilostachyin and Psilostachyin C on Trypanosoma cruzi

    Science.gov (United States)

    Papademetrio, Daniela; Batlle, Alcira; Martino, Virginia S.; Frank, Fernanda M.; Lombardo, María E.

    2016-01-01

    Trypanosoma cruzi is the causative agent of Chagas’ disease, which is a major endemic disease in Latin America and is recognized by the WHO as one of the 17 neglected tropical diseases in the world. Psilostachyin and psilostachyin C, two sesquiterpene lactones isolated from Ambrosia spp., have been demonstrated to have trypanocidal activity. Considering both the potential therapeutic targets present in the parasite, and the several mechanisms of action proposed for sesquiterpene lactones, the aim of this work was to characterize the mode of action of psilostachyin and psilostachyin C on Trypanosoma cruzi and to identify the possible targets for these molecules. Psilostachyin and psilostachyin C were isolated from Ambrosia tenuifolia and Ambrosia scabra, respectively. Interaction of sesquiterpene lactones with hemin, the induction of oxidative stress, the inhibition of cruzipain and trypanothione reductase and their ability to inhibit sterol biosynthesis were evaluated. The induction of cell death by apoptosis was also evaluated by analyzing phosphatidylserine exposure detected using annexin-V/propidium iodide, decreased mitochondrial membrane potential, assessed with Rhodamine 123 and nuclear DNA fragmentation evaluated by the TUNEL assay. Both STLs were capable of interacting with hemin. Psilostachyin increased about 5 times the generation of reactive oxygen species in Trypanosoma cruzi after a 4h treatment, unlike psilostachyin C which induced an increase in reactive oxygen species levels of only 1.5 times. Only psilostachyin C was able to inhibit the biosynthesis of ergosterol, causing an accumulation of squalene. Both sesquiterpene lactones induced parasite death by apoptosis. Upon evaluating the combination of both compounds, and additive trypanocidal effect was observed. Despite their structural similarity, both sesquiterpene lactones exerted their anti-T. cruzi activity through interaction with different targets. Psilostachyin accomplished its

  16. Substrate Directed Regioselective Monobromination of Aralkyl Ketones Using N-Bromosuccinimide Catalysed by Active Aluminium Oxide: α -Bromination versus Ring Bromination.

    Science.gov (United States)

    Mohan, Reddy Bodireddy; Reddy, G Trivikram; Gangi Reddy, N C

    2014-01-01

    Bromination of aralkyl ketones using N-bromosuccinimide in presence of active Al2O3 provided either α -monobrominated products in methanol at reflux or mononuclear brominated products in acetonitrile at reflux temperature with excellent isolated yields depending on the nature of substrate employed. The α -bromination was an exclusive process when aralkyl ketones containing moderate activating/deactivating groups were subjected to bromination under acidic Al2O3 conditions in methanol at reflux while nuclear functionalization was predominant when aralkyl ketones containing high activating groups were utilized for bromination in presence of neutral Al2O3 conditions in acetonitrile at reflux temperature. In addition, easy isolation of products, use of inexpensive catalyst, short reaction time (10-20 min), and safe operational practice are the major benefits in the present protocol.

  17. The crystal structure and superconducting properties of monatomic bromine.

    Science.gov (United States)

    Duan, Defang; Meng, Xing; Tian, Fubo; Chen, Changbo; Wang, Liancheng; Ma, Yanming; Cui, Tian; Liu, Bingbing; He, Zhi; Zou, Guangtian

    2010-01-13

    The crystal structure and superconducting properties of monatomic bromine under high pressure have been studied by first-principles calculations. We have found the following phase transition sequence with increasing pressure: from body-centered orthorhombic (bco, phase II) to body-centered tetragonal structure (bct, phase III) at 126 GPa, then to face-centered cubic structure (fcc, phase IV) at 157 GPa, which is stable at least up to 300 GPa. The calculated superconducting critical temperature T(c) = 1.46 K at 100 GPa is consistent with the experimental value of 1.5 K. In addition, our results of T(c) decrease with increasing pressure in all the monatomic phases of bromine, similar to monatomic iodine. Further calculations show that the decrease of λ with pressure in phase IV is mainly attributed to the weakening of the 'soft' vibrational mode caused by pressure.

  18. New Methods for Labeling RGD Peptides with Bromine-76

    Directory of Open Access Journals (Sweden)

    Lixin Lang, Weihua Li, Hong-Mei Jia, De-Cai Fang, Shushu Zhang, Xilin Sun, Lei Zhu, Ying Ma, Baozhong Shen, Dale O. Kiesewetter, Gang Niu, Xiaoyuan Chen

    2011-01-01

    Full Text Available Direct bromination of the tyrosine residues of peptides and antibodies with bromine-76, to create probes for PET imaging, has been reported. For peptides that do not contain tyrosine residues, however, a prosthetic group is required to achieve labeling via conjugation to other functional groups such as terminal α-amines or lysine ε-amines. The goal of this study was to develop new strategies for labeling small peptides with Br-76 using either a direct labeling method or a prosthetic group, depending on the available functional group on the peptides. A new labeling agent, N-succinimidyl-3-[76Br]bromo-2,6-dimethoxybenzoate ([76Br]SBDMB was prepared for cyclic RGD peptide labeling. N-succinimidyl-2, 6-dimethoxybenzoate was also used to pre-attach a 2, 6-dimethoxybenzoyl (DMB moiety to the peptide, which could then be labeled with Br-76. A competitive cell binding assay was performed to determine the binding affinity of the brominated peptides. PET imaging of U87MG human glioblastoma xenografted mice was performed using [76Br]-BrE[c(RGDyK]2 and [76Br]-BrDMB-E[c(RGDyK]2. An ex vivo biodistribution assay was performed to confirm PET quantification. The mechanisms of bromination reaction between DMB-c(RGDyK and the brominating agent CH3COOBr were investigated with the SCRF-B3LYP/6-31G* method with the Gaussian 09 program package. The yield for direct labeling of c(RGDyK and E[c(RGDyK]2 using chloramine-T and peracetic acid at ambient temperature was greater than 50%. The yield for [76Br]SBDMB was over 60% using peracetic acid. The conjugation yields for labeling c(RGDfK and c(RGDyK were over 70% using the prosthetic group at room temperature. Labeling yield for pre-conjugated peptides was over 60%. SDMB conjugation and bromination did not affect the binding affinity of the peptides with integrin receptors. Both [76Br]Br-E[c(RGDyK]2 and [76Br]BrDMB-E[c(RGDyK]2 showed high tumor uptake in U87MG tumor bearing mice. The specificity of the imaging tracers

  19. [Fungistatic activity of a sesquiterpene lactone (tomentosin) isolated from fresh Inula viscosa (Asteraceae) flowers from the Puglia region].

    Science.gov (United States)

    Cafarchia, C; De Laurentis, N; Milillo, M A; Losacco, V; Puccini, V

    2001-09-01

    A sesquiterpene lactone, tomentosin, has been isolated and identified form Inula viscosá Ait (Asteraceae) flowers. The molecule, at 1 mg/ml concentration, showed to be active in vitro against Microsporum canis, Microsporum gypseum and Trichophyton mentagrophytes.

  20. 9-Hydroxyfurodysinin-O-ethyl Lactone: A New Sesquiterpene Isolated from the Tropical Marine Sponge Dysidea arenaria

    Directory of Open Access Journals (Sweden)

    P. Karuso

    2005-10-01

    Full Text Available A new sesquiterpene, 9-hydroxyfurodysinin-O-ethyl lactone, has been isolated from a New Caledonian Dysidea arenaria, along with three known compounds. The possible incorporation of the ethyl ether from the extraction solvent is discussed.

  1. Bromination of hydrocarbons with CBr4, initiated by light-emitting diode irradiation

    Directory of Open Access Journals (Sweden)

    Yuta Nishina

    2013-08-01

    Full Text Available The bromination of hydrocarbons with CBr4 as a bromine source, induced by light-emitting diode (LED irradiation, has been developed. Monobromides were synthesized with high efficiency without the need for any additives, catalysts, heating, or inert conditions. Action and absorption spectra suggest that CBr4 absorbs light to give active species for the bromination. The generation of CHBr3 was confirmed by NMR spectroscopy and GC–MS spectrometry analysis, indicating that the present bromination involves the homolytic cleavage of a C–Br bond in CBr4 followed by radical abstraction of a hydrogen atom from a hydrocarbon.

  2. Specific heat of pristine and brominated graphite fibers, composites and HOPG. [Highly Oriented Pyrolytic Graphite

    Science.gov (United States)

    Hung, Ching-Chen; Maciag, Carolyn

    1987-01-01

    Differential scanning calorimetry was used to obtain specific heat values of pristine and brominated P-100 graphite fibers and brominated P-100/epoxy composite as well as pristine and brominated highly oriented pyrolytic graphite (HOPG) for comparison. Based on the experimental results obtained, specific heat values are calculated for several different temperatures, with a standard deviation estimated at 1.4 percent of the average values. The data presented here are useful in designing heat transfer devices (such as airplane de-icing heaters) from bromine fibers.

  3. Elemental Bromine Production by TiO2 Photocatalysis and/or Ozonation.

    Science.gov (United States)

    Parrino, Francesco; Camera Roda, Giovanni; Loddo, Vittorio; Palmisano, Leonardo

    2016-08-22

    Significant production of elemental bromine (Br2 ) was observed for the first time when treating bromide containing solutions at acidic pH, with TiO2 photocatalyst, ozone, or a combination thereof. Br2 selectivities up to approximately 85 % were obtained and the corresponding bromine mass balance values satisfied. The process is general and may be applied at a laboratory scale for green bromination reactions, or industrially as a cheap, safe, and environmentally sustainable alternative to the currently applied bromine production methods.

  4. High selectively oxidative bromination of toluene derivatives by the H2O2-HBr system

    Institute of Scientific and Technical Information of China (English)

    Jie Ju; Yu Jin Li; Jian Rong Gao; Jian Hong Jia; Liang Han; Wei Jian Sheng; Yi Xia Jia

    2011-01-01

    An aqueous solution of hydrogen peroxide and hydrogen bromide illuminated by a 60 W incandescent light bulb serves as a source of bromine radicals. Various substituted toluenes (NO2,Cl, Br, H, CH3) were high selectively brominated at the benzyl position for monobromination in CH2C12 at ice water with catalyst free. This simple but effective bromination of toluene derivatives with an aqueous H2O2-HBr system is characterized with the use of inexpensive reagents and a lower impact on the environment, which make it a good alternative to the existing bromination methods.

  5. Helikaurolides A-D with a Diterpene-Sesquiterpene Skeleton from Supercritical Fluid Extracts of Helianthus annuus L. var. Arianna.

    Science.gov (United States)

    Torres, Ascensión; Molinillo, José M G; Varela, Rosa M; Casas, Lourdes; Mantell, Casimiro; Martínez de la Ossa, Enrique J; Macías, Francisco A

    2015-10-02

    Four novel compounds (1-4) with an unprecedented skeleton that combines a sesquiterpene lactone and a kaurane diterpene acid were isolated from Helianthus annuus L. var. Arianna extract, which was obtained under supercritical conditions. The structures of 1-4 were elucidated by NMR and MS analyses. The biosynthetic routes involve sesquiterpene lactones and kauranic acid, both of which were previously isolated from this species.

  6. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    OpenAIRE

    Tas, E.; M. Peleg; D. U. Pedersen; Matveev, V; A. Pour Biazar; Luria, M.

    2006-01-01

    International audience; The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS) chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the basic chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. Th...

  7. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    OpenAIRE

    A. Pour Biazar; Matveev, V; D. U. Pedersen; M. Peleg; Tas, E.; Luria, M.

    2006-01-01

    The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS) chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the ...

  8. Inorganic bromine in the marine boundary layer: a critical review

    Directory of Open Access Journals (Sweden)

    R. Sander

    2003-06-01

    Full Text Available The cycling of inorganic bromine in the marine boundary layer (mbl has received increased attention in recent years. Bromide, a constituent of sea water, is injected into the atmosphere in association with sea-salt aerosol by breaking waves on the ocean surface. Measurements reveal that supermicrometer sea-salt aerosol is depleted in bromine by about 50% relative to conservative tracers, whereas marine submicrometer aerosol is often enriched in bromine. Model calculations, laboratory studies, and field observations strongly suggest that these depletions reflect the chemical transformation of particulate bromide to reactive inorganic gases that influence the processing of ozone and other important constituents of marine air. However, currently available techniques cannot reliably quantify many chem{Br}-containing compounds at ambient concentrations and, consequently, our understanding of inorganic Br cycling over the oceans and its global significance are uncertain. To provide a more coherent framework for future research, we have reviewed measurements in marine aerosol, the gas phase, and in rain. We also summarize sources and sinks, as well as model and laboratory studies of chemical transformations. The focus is on inorganic bromine over the open oceans, excluding the polar regions. The generation of sea-salt aerosol at the ocean surface is the major tropospheric source producing about 6.2 Tg/a of bromide. The transport of  Br from continents (as mineral aerosol, and as products from biomass-burning and fossil-fuel combustion can be of local importance. Transport of degradation products of long-lived Br-containing compounds from the stratosphere and other sources contribute lesser amounts. Available evidence suggests that, following aerosol acidification, sea-salt bromide reacts to form Br2 and BrCl that volatilize to the gas phase and photolyze in daylight to produce atomic Br and Cl. Subsequent transformations can destroy

  9. Antimicrobial drimane sesquiterpenes and their effect on endophyte communities in the medical tree Warburgia ugandensis

    Directory of Open Access Journals (Sweden)

    Sigrid eDrage

    2014-02-01

    Full Text Available Metabolite profiles (GC–MS, drimane sesquiterpenes, sugars and sugar alcohols, were compared with bacterial and fungal endophyte communities (T-RFLP, DNA clones, qPCR in leaves and roots of the pepper bark tree, Warburgia ugandensis (Canellaceae. Ten individuals each were assessed from two locations east and west of the Great Rift Valley, Kenya, Africa, which differed in humidity and vegetation, closed forest versus open savannah. Despite organ- and partially site-specific variation of drimane sesquiterpenes, no clear effects on bacterial and fungal endophyte communities could be detected. The former were dominated by gram-negative Gammaproteobacteria, Pseudomonadaceae and Enterobacteriaceae, as well as gram-positive Firmicutes; the fungal endophyte communities were more diverse but no specific groups dominated. Despite initial expectations, the endophyte community of the pepper bark tree did not differ from other trees that much.

  10. Disesquiterpene and sesquiterpene coumarins from Ferula pseudalliacea, and determination of their absolute configurations.

    Science.gov (United States)

    Dastan, Dara; Salehi, Peyman; Reza Gohari, Ahmad; Zimmermann, Stefanie; Kaiser, Marcel; Hamburger, Matthias; Reza Khavasi, Hamid; Ebrahimi, Samad Nejad

    2012-06-01

    The first disesquiterpene coumarin, sanandajin, five sesquiterpene coumarins, kamolonol acetate, fekrynol acetate, ethyl galbanate, methyl galbanate, farnesiferol B, and a sesquiterpene, aristolone, were isolated from a n-hexane extract of Ferula pseudalliacea roots. The structures were elucidated by 1D and 2D NMR, HR-ESIMS data, and kamolonol acetate was confirmed by single-crystal X-ray analysis. The absolute configuration of compounds was established by comparison of experimental and simulated ECD spectra using time dependence density function theory (TDDFT). In vitro antiplasmodial activity against Plasmodium falciparum K1 strain was determined. sanandajin, kamolonol acetate and methyl galbanate showed moderate antiplasmodial activity, with IC(50) values of 2.6, 16.1 and 7.1 μM, respectively.

  11. Guaiane sesquiterpenes and isopimarane diterpenes from an endophytic fungus Xylaria sp.

    Science.gov (United States)

    Wu, Shao-Hua; He, Jian; Li, Xiao-Nian; Huang, Rong; Song, Fei; Chen, You-Wei; Miao, Cui-Ping

    2014-09-01

    Nine oxygenated guaiane-type sesquiterpenes and three isopimarane diterpenes were isolated from the culture broth of an endophytic fungus, Xylaria sp. YM 311647, obtained from Azadirachta indica. The structures of these compounds were elucidated by interpretation of spectroscopic data. The absolute configurations of two of these were confirmed by X-ray crystallographic analysis. All of the compounds were tested for their antifungal activities against five pathogenic fungal cells. The results showed that nine sesquiterpenes were moderately active against Candida albicans and Hormodendrum compactum with MIC values ranging from 32 to 256μg/ml, while the diterpenes were more active; One of these exhibited the most potent inhibitory activity against C. albicans and Pyricularia oryzae with MIC values of 16μg/ml.

  12. Four new eudesmane-type sesquiterpenes from the basal leaves of Salvia plebeia R. Br.

    Science.gov (United States)

    Dai, Yiqun; Liu, Li; Xie, Guoyong; Chen, Yujie; Qin, Xiaoying; Wang, Qi; Li, Jie; Qin, Minjian

    2014-04-01

    Four new eudesmane-type sesquiterpenes, named plebeiolide A-C (1-3) and plebeiafuran (4), together with a known eudesmanolide (5), were isolated from the basal leaves of Salvia plebeia R. Br. Their structures were elucidated by extensive spectroscopic analysis including 1D and 2D NMR, HR-ESI-MS spectra. The absolute configuration of compound 1 was confirmed by single-crystal X-ray analysis and CD spectra. The inhibitory activity of isolated compounds toward NO production in lipopolysaccharide-induced RAW264.7 cells was evaluated and compounds 3 and 4 showed moderate inhibitory activity. In addition, the sesquiterpene lactones in Lamiaceae plants may possess some chemosystematic implications at intergeneric and intrageneric levels.

  13. Quantitative analysis of sesquiterpene lactones in extract of Arnica montana L. by 1H NMR spectroscopy.

    Science.gov (United States)

    Staneva, Jordanka; Denkova, Pavletta; Todorova, Milka; Evstatieva, Ljuba

    2011-01-01

    (1)H NMR spectroscopy was used as a method for quantitative analysis of sesquiterpene lactones present in a crude lactone fraction isolated from Arnica montana. Eight main components - tigloyl-, methacryloyl-, isobutyryl- and 2-methylbutyryl-esters of helenalin (H) and 11α,13-dihydrohelenalin (DH) were identified in the studied sample. The method allows the determination of the total amount of sesquiterpene lactones and the quantity of both type helenalin and 11α,13-dihydrohelenalin esters separately. Furthermore, 6-O-tigloylhelenalin (HT, 1), 6-O-methacryloylhelenalin (HM, 2), 6-O-tigloyl-11α,13-dihydrohelenalin (DHT, 5), and 6-O-methacryloyl-11α,13-dihydrohelenalin (DHM, 6) were quantified as individual components.

  14. Four new sesquiterpenes from the rhizomes of Curcuma phaeocaulis and their iNOS inhibitory activities.

    Science.gov (United States)

    Ma, Jiang-Hao; Wang, Ying; Liu, Yue; Gao, Su-Yu; Ding, Li-Qin; Zhao, Feng; Chen, Li-Xia; Qiu, Feng

    2015-05-01

    Three new guaiane-type sesquiterpenes named phaeocaulisins K-M (1-3), and one germacrane-type sesquiterpenoid with new ring system of 1,5- and 1,8-ether groups named phagermadiol (4), were isolated from rhizomes of Curcuma phaeocaulis. Their structures were established based on extensive spectroscopic analysis. Compound 1, the first example of norsesquiterpene with tropone backbone, and compound 3 with a novel 1,2-dioxolane sesquiterpene alcohol were isolated from the genus Curcuma. All of the isolated compounds were tested for inhibitory activity against lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 macrophages. Compound 3 inhibited NO production with IC50 value of 6.05 ± 0.43 μM. The plausible biosynthetic pathway for compounds 3 and 4 in C. phaeocaulis was also discussed.

  15. Anti-inflammatory profile of dehydrocostic acid, a novel sesquiterpene acid with a pharmacophoric conjugated diene.

    Science.gov (United States)

    Hernández, V; Máñez, S; Recio, M C; Giner, R M; Ríos, J L

    2005-10-01

    Sesquiterpene acids are natural products that, in contrast with the thoroughly studied sesquiterpene lactones, have received little pharmacological attention. A good source of this class of compounds is Inula viscosa (Asteraceae), a plant with documented anti-inflammatory effects. The present paper gives the results of our investigations on the biochemical mechanisms involved in the anti-inflammatory activity of one such compound, dehydrocostic acid. The most salient findings were that in vitro dehydrocostic acid inhibits leukotriene B(4) production (IC(50)=22 microM), elastase activity (IC(50)=43 microM) and bee venom phospholipase A(2) activity (IC(50)=17 microM). Furthermore, this sesquiterpenoid was effective on some models of acute edema induced by PLA(2) and 12-O-tetradecanoylphorbol 13-acetate (TPA) Comparison of these data with that known for ilicic acid firmly suggests that the presence of a semiplanar ring A is essential for an improved inhibitory activity on inflammatory mediators.

  16. Bergamotane Sesquiterpenes with Alpha-Glucosidase Inhibitory Activity from the Plant Pathogenic Fungus Penicillium expansum.

    Science.gov (United States)

    Ying, You-Min; Fang, Cheng-An; Yao, Feng-Qi; Yu, Yuan; Shen, Ying; Hou, Zhuo-Ni; Wang, Zhen; Zhang, Wei; Shan, Wei-Guang; Zhan, Zha-Jun

    2017-01-01

    Two new bergamotane sesquiterpene lactones, named expansolides C and D (1 and 2), together with two known compounds expansolides A and B (3 and 4), were isolated from the plant pathogenic fungus Penicillium expansum ACCC37275. The structures of the new compounds were established by detailed analyses of the spectroscopic data, especially 1D-, 2D-NMR, and HR-ESI-MS. In an in vitro bioassay, the epimeric mixture of expansolides C and D (1 and 2) (in a ratio of 2:1 at the temprature of the bioassay) exhibited more potent α-glucosidase inhibitory activity (IC50 =0.50 ± 0.02 mm) as compared with the positive control acarbose (IC50 = 1.90 ± 0.05 mm). To the best of our knowledge, it was the first report on the α-glucosidase inhibitory activity of bergamotane sesquiterpenes.

  17. A New Sesquiterpene from Caragana intermediia and Its Anti-Pyricularia oryzae P-2b Activity

    Institute of Scientific and Technical Information of China (English)

    SUN Zhi-Hua; HU Chang-Qi; WANG Jin-Yi

    2008-01-01

    A new aromadendrane-type sesquiterpene,(-)-alloaromadendrane-4β,10β-diol(1),has been isolated from the aerial part of Caragana intermediia,the structure of which was established by spectroscopic methods,including X-ray analysis that provided its relative stereochemistry.Bioassay showed that 1 possessed anti-Pyricularia oryzae P-2b activity with an MIC(minimum inhibitory concentration)value of 10μg/mL.

  18. Total Synthesis of Two 4, 5-Dioxo-seco-eudesmane Sesquiterpenes

    Institute of Scientific and Technical Information of China (English)

    Li Jing FANG; Chen Xi ZHANG; Jin Chun CHEN; Guo Jun ZHENG; Yu Lin LI

    2005-01-01

    A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γeudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from (+)-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.

  19. Sesquiterpene lactones. XXXIII. Guaianolides in the subgenus Psephellus (Cass.) Schmalh., genus Centaurea L.

    OpenAIRE

    Gerard Nowak; Bohdan Drożdż; Miroslav Holub; Agnieszka Łagodzińska

    2014-01-01

    Sesquiterpene lactones were found to occur in all of the studied species of the subgenus Psephellus (Cass.) Schmalh. Differing compositions were found in the representatives of three sections. In Centaurea declinata MB. from the section Leucophylle (Sosn.) Sosn.. 15-deoxyrepin, linichlorin B and cynaropicrin were found. Linichlorin B dominated in Centaurea hypoleucu DC. from section Hypoleucae (Sosn.) Sosn., while in the species classified in section Psephellus Sosn., repin, acroptilin, jener...

  20. Sesquiterpene lactones. XXXIII. Guaianolides in the subgenus Psephellus (Cass. Schmalh., genus Centaurea L.

    Directory of Open Access Journals (Sweden)

    Gerard Nowak

    2014-01-01

    Full Text Available Sesquiterpene lactones were found to occur in all of the studied species of the subgenus Psephellus (Cass. Schmalh. Differing compositions were found in the representatives of three sections. In Centaurea declinata MB. from the section Leucophylle (Sosn. Sosn.. 15-deoxyrepin, linichlorin B and cynaropicrin were found. Linichlorin B dominated in Centaurea hypoleucu DC. from section Hypoleucae (Sosn. Sosn., while in the species classified in section Psephellus Sosn., repin, acroptilin, jenerin, centaurepensin and, in some, also cynaropicrin. dominated.

  1. Dihydro-β-agarofuran sesquiterpene pyridine alkaloids from the seeds of Euonymus hamiltonianus

    Directory of Open Access Journals (Sweden)

    Mudasir A. Tantry

    2016-09-01

    Full Text Available Plants of the Celastraceae family produce various dihydro-β-agarofuran sesquiterpene pyridine alkaloids. Two dihydro-β-agarofuran sesquitepene pyridine alkaloids (1,2 apart from four known compounds euojaponin C (3, wilforine (4, austronine (5 and O9-benzoyl-O9-deacetylevonine (6, were isolated from the ripe seeds of Euonymus hamiltonianus. Their chemical structures were elucidated mainly by analysis of NMR and MS spectral data. All compounds were evaluated for insecticidal activity.

  2. Hepatocurative potential of sesquiterpene lactones of Taraxacum officinale on carbon tetrachloride induced liver toxicity in mice.

    Science.gov (United States)

    Mahesh, A; Jeyachandran, R; Cindrella, L; Thangadurai, D; Veerapur, V P; Muralidhara Rao, D

    2010-06-01

    The hepatocurative potential of ethanolic extract (ETO) and sesquiterpene lactones enriched fraction (SL) of Taraxacum officinale roots was evaluated against carbon tetrachloride (CCl 4 ) induced hepatotoxicity in mice. The diagnostic markers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin contents were significantly elevated, whereas significant reduction in the level of reduced glutathione (GSH) and enhanced hepatic lipid peroxidation, liver weight and liver protein were observed in CCl 4 induced hepatotoxicity in mice. Post-treatment with ETO and SL significantly protected the hepatotoxicity as evident from the lower levels of hepatic enzyme markers, such as serum transaminase (ALT, AST), ALP and total bilirubin. Further, significant reduction in the liver weight and liver protein in drug-treated hepatotoxic mice and also reduced oxidative stress by increasing reduced glutathione content and decreasing lipid peroxidation level has been noticed. The histopathological evaluation of the liver also revealed that ETO and SL reduced the incidence of liver lesions induced by CCl 4 . The results indicate that sesquiterpene lactones have a protective effect against acute hepatotoxicity induced by the administration of CCl 4 in mice. Furthermore, observed activity of SL may be due to the synergistic action of two sesquiterpene lactones identified from enriched ethyl acetate fraction by HPLC method.

  3. Melanogenesis inhibitory activity of sesquiterpenes from Canarium ovatum resin in mouse B16 melanoma cells.

    Science.gov (United States)

    Kikuchi, Takashi; Watanabe, Kensuke; Tochigi, Yuichi; Yamamoto, Ayako; Fukatsu, Makoto; Ezaki, Yoichiro; Tanaka, Reiko; Akihisa, Toshihiro

    2012-08-01

    Four known sesquiterpene alcohols, i.e., 1-4, ten triterpene alcohols, i.e., 5-14, and four triterpene acids, i.e., 15-18, were isolated from the MeOH extract of Canarium ovatum resin (elemi resin). Upon evaluation of the previously described compounds 1-18 on the melanogenesis in B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), three sesquiterpene alcohols, i.e., cryptomeridiol (1), 4-epicryptomeridiol (2), and cadin-1(14)-ene-7α,11-diol (4), exhibited inhibitory effects with 27.4-34.1 and 39.0-56.9% reduction of melanin content at 50 and 100 μM, respectively, with no or very low toxicity to the cells (80.9-103.9% of cell viability at 100 μM). Western-blot analysis revealed that compounds 1 and 2 reduced the protein levels of MITF (=microphtalmia-associated transcription factor), tyrosinase, and TRP-2 (=tyrosine-related protein 2), mostly in a concentration-dependent manner, suggesting that these compounds exhibit melanogenesis inhibitory activity on α-MSH-stimulated B16 melanoma cells by, at least in part, inhibiting the expression of MITF, followed by decreasing the expression of tyrosinase and TRP-2. Three sesquiterpene alcohols, i.e., 1, 2, and 4, are, therefore, considered to be valuable as potential skin-whitening agents.

  4. Developmentally regulated sesquiterpene production confers resistance to Colletotrichum gloeosporioides in ripe pepper fruits.

    Directory of Open Access Journals (Sweden)

    Sangkyu Park

    Full Text Available Sesquiterpenoid capsidiol, exhibiting antifungal activity against pathogenic fungus, is accumulated in infected ripe pepper fruits. In this study, we found a negative relation between the capsidiol level and lesion size in fruits infected with Colletotrichum gloeosporioides, depending on the stage of ripening. To understand the developmental regulation of capsidiol biosynthesis, fungal-induced gene expressions in the isoprenoid biosynthetic pathways were examined in unripe and ripe pepper fruits. The sterol biosynthetic pathway was almost shut down in healthy ripe fruits, showing very low expression of hydroxymethyl glutaryl CoA reductase (HMGR and squalene synthase (SS genes. In contrast, genes in the carotenoid pathway were highly expressed in ripe fruits. In the sesquiterpene pathway, 5-epi-aristolochene synthase (EAS, belonging to a sesquiterpene cyclase (STC family, was significantly induced in the ripe fruits upon fungal infection. Immunoblot and enzyme activity analyses showed that the STCs were induced both in the infected unripe and ripe fruits, while capsidiol was synthesized discriminatively in the ripe fruits, implying diverse enzymatic specificity of multiple STCs. Thereby, to divert sterol biosynthesis into sesquiterpene production, infected fruits were pretreated with an SS inhibitor, zaragozic acid (ZA, resulting in increased levels of capsidiol by more than 2-fold in the ripe fruits, with concurrent reduction of phytosterols. Taken together, the present results suggest that the enhanced expression and activity of EAS in the ripe fruits play an important role in capsidiol production, contributing to the incompatibility between the anthracnose fungus and the ripe pepper fruits.

  5. Isolation of Persicaria minor sesquiterpene synthase promoter and its deletions for transgenic Arabidopsis thaliana

    Science.gov (United States)

    Omar, Aimi Farehah; Ismail, Ismanizan

    2016-11-01

    Sesquiterpene synthase (SS) catalyzes the formation of sesquiterpenes from farnesyl diphosphate (FDP) via carbocation intermediates. In this study, the promoter region of sesquiterpene synthase was isolated from Persicaria minor to identify possible cis-acting elements in the promoter. The full-length PmSS promoter of P. minor is 1824-bp sequences. The sequence was analyzed and several putative cis-acting regulatory elements were identified. Three cis-acting regulatory elements were selected for deletion analysis which are cis-acting element involved in wound responsiveness (WUN), cis - acting element involved in defense and stress responsiveness (TC) and cis-acting element involved in ABA responsiveness (ABRE). Series of deletions were conducted to assess the promoter activity producing three truncated fragments promoter; Prom 2 1606-bp, Prom 3 1144- bp, and Prom 4 921-bp. The full-length promoter and its deletion series were cloned into the pBGWFS7 vector which contain β-glucuronidase (GUS) gene and green fluorescent protein (GFP) as the reporter gene. All constructs were successfully transformed into Arabidopsis thaliana based on PCR of positive BASTA resistance plants.

  6. SESQUITERPENE RICH VOLATILE SEED OIL OF TAGETES PATULA L. FROM NORTHWEST IRAN

    Directory of Open Access Journals (Sweden)

    M. B. HASSANPOURAGHDAM

    2011-10-01

    Full Text Available Hydrodistilled volatile seed oil composition of commonly growing ornamental Tagetes patula L. was analyzed for its constituents by GC/MS. Forty constituents were identified, comprising 94% of the total oil. Sesquiterpene hydrocarbons (52.7% and oxygenated sesquiterpenes (15.8% were the main subclasses of volatile oil components followed by monoterpene hydrocarbons (12.6%. The principle constituents of the volatile oil were (E-caryophyllene (44.6% caryophyllene oxide (14.8%, germacrene D (3.8%, (Z-β-ocimene (3.8% and limonene (3.7%. From chemical point of view, oxides (15.7% were the predominant group of components with caryophyllene oxide as their main representative. α-terthienyl (3.8% comprised partially large amount in the volatile oil content despite of its polar and less-volatile nature. Taking into account the volatile oil profile, the chemical composition of the volatile seed oil of commonly growing ornamental T. patula L. was characterized as sesquiterpene and α-terthienyl rich one probably with appreciable biocidal (Insecticidal and nematicidal and pharmacological potential.

  7. Determination of iodine and bromine in coal and atmospheric particles by inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Sun, Mingxing; Gao, Yunchuan; Wei, Biwen; Wu, Xiaowei

    2010-04-15

    Bromine and iodine in atmospheric particles or coal can cause environmental problems such as destruction of ozone in the atmosphere; therefore, the presence of these compounds has recently received increased attention. Here, a rapid and reliable method for the simultaneous determination of total bromine and iodine using ICP-MS analysis is described. Samples were dissolved in mixtures of 5 mL of HNO(3) and 2 mL of H(2)O(2) in a high pressure microwave digester. The solution was then oxidized by per-sulfate (Na(2)S(2)O(8)) in addition to a small amount of silver nitrate, after which the total bromine and iodine were measured simultaneously by ICP-MS. The signal memory effects of bromine and iodine during analysis were effectively decreased by washing with a new mixture agent (2% alcohol acidic solution, pH 1-2 adjusted with HCl). The detection limits for bromine and iodine using this method were about 3.2 microg L(-1) and 1.1 microg L(-1), respectively. Additionally, the spike recoveries were between 78.7% and 121% for bromine and iodine analysis, while the relative standard deviations ranged from 4.3% to 9.7%, and from 1.5% to 3.4% for bromine and iodine, respectively. The results of this study indicate that the method described here is suitable for the analysis of micro-amounts of bromine and iodine in atmospheric particles and coal samples.

  8. 40 CFR 721.775 - Brominated aromatic com-pound (generic name).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Brominated aromatic com-pound (generic name). 721.775 Section 721.775 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.775 Brominated aromatic com-pound (generic name). (a)...

  9. Distribution of bromine in mixed iodide-bromide organolead perovskites and its impact on photovoltaic performance

    NARCIS (Netherlands)

    Zhou, Yang; Wang, Feng; Fang, Hong-Hua; Loi, Maria Antonietta; Xie, Fang-Yan; Zhao, Ni; Wong, Ching-Ping

    2016-01-01

    Mixed iodide-bromide (I-Br) organolead perovskites are of great interest for both single junction and tandem solar cells since the optical bandgap of the materials can be tuned by varying the bromine to iodine ratio. Yet, it remains unclear how bromine incorporation modifies the properties of the pe

  10. The Cyclotron Production and Nuclear Imaging of BROMINE-77.

    Science.gov (United States)

    Galiano, Eduardo

    In this investigation, bromine-77 was produced with a medical cyclotron and imaged with gamma cameras. Br -77 emits a 240 kev photon with a half life of 56 hours. The C-Br bond is stronger than the C-I bond and bromine is not collected in the thyroid. Bromine can be used to label many organic molecules by methods analogous to radioiodination. The only North American source of Br-77 in the 70's and 80's was Los Alamos National Laboratory, but it discontinued production in 1989. In this method, a p,3n reaction on Br-77 produces Kr-77 which decays with a 1.2 hour half life to Br-77. A cyclotron generated 40 MeV proton beam is incident on a nearly saturated NaBr or LiBr solution contained in a copper or titanium target. A cooling chamber through which helium gas is flowed separates the solution from the cyclotron beam line. Helium gas is also flowed through the solution to extract Kr-77 gas. The mixture flows through a nitrogen trap where Kr-77 freezes and is allowed to decay to Br-77. Eight production runs were performed, three with a copper target and five with a titanium target with yields of 40, 104, 180, 679, 1080, 685, 762 and 118 uCi respectively. Gamma ray spectroscopy has shown the product to be very pure, however corrosion has been a major obstacle, causing the premature retirement of the copper target. Phantom and in-vivo rat nuclear images, and an autoradiograph in a rat are presented. The quality of the nuclear scans is reasonable and the autoradiograph reveals high isotope uptake in the renal parenchyma, a more moderate but uniform uptake in pulmonary and hepatic tissue, and low soft tissue uptake. There is no isotope uptake in the brain or the gastric mucosa.

  11. Modelling chemistry over the Dead Sea: bromine and ozone chemistry

    OpenAIRE

    Smoydzin, L.; Glasow, R

    2009-01-01

    Measurements of O3 and BrO concentrations over the Dead Sea indicate that Ozone Depletion Events (ODEs), widely known to happen in polar regions, are also likely to occur over the Dead Sea due to the very high bromine content of the Dead Sea water. However, we show that BrO and O3 levels as they are detected cannot solely be explained by high Br levels in the Dead Sea water and the release of gas phase halogen...

  12. Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

    Science.gov (United States)

    Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

    2009-01-16

    Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

  13. Deriving an atmospheric budget of total organic bromine using airborne in-situ measurements of brominated hydrocarbons in the Western Pacific during SHIVA

    Science.gov (United States)

    Sala, Stephan; Bönisch, Harald; Keber, Timo; Oram, Dave; Mills, Graham; Engel, Andreas

    2014-05-01

    Halogenated hydrocarbons play a major role as precursors for stratospheric ozone depletion. Released from the surface in the troposphere, the halocarbons reach the stratosphere via transport through the tropical tropopause layer. The contribution of the so called very short lived species (VSLS), having atmospheric lifetimes of less than half a year as sources gases for stratospheric bromine is significant. Source gas observations of long-lived bromine compounds and VSLS have so far not been able to explain the amount of bromine derived in the stratosphere from observations of BrO and modeling of the ratio of BrO to total bromine. Due to the short lifetimes and the high atmospheric variability, the representativeness of the available observations of VSLS source gases remains unclear, as these may vary with region and display seasonal variability. During the SHIVA (Stratospheric Ozone: Halogen Impacts in a Varying Atmosphere) project an extensive dataset with over 700 samples of ambient air of all halogen species relevant for the atmospheric budget of total organic bromine (long lived halocarbons: H-1301, H-1211, H-1202, H-2402 and CH3Br, very short lived substances: CHBr3, CH2Br2, CHBr2Cl, CHBrCl2 and CHBrCl) have been collected from onboard the FALCON aircraft in the West Pacific region. Measurements were performed with the newly developed fully-automated in-situ instrument GHOST-MS (Gas chromatograph for the Observation of Tracers - coupled with a Mass Spectrometer) by the Goethe University of Frankfurt and with the onboard whole-air sampler WASP with subsequent ground based state-of-the-art GC/MS analysis by the University of East Anglia. We will present the datasets, compare these to other observation, derive a bromine budget for the West Pacific and derive an estimate of the amount of bromine from VSLS reaching the stratosphere. Using the mean mixing ratios in the upper troposphere of the halocarbons mentioned above, the calculated budget of the total organic

  14. Effects of bromine on mitosis in root-tips of Allium cepa

    Energy Technology Data Exchange (ETDEWEB)

    Chury, J.; Slouka, V.

    1949-01-01

    The root-tips of Allium cepa, 1.5-2 cm. long, were exposed to pure bromine vapor for five minutes. The root-tips were then washed for ten minutes in water, and kept in fresh-water at a temperature of 20-24/sup 0/C. Squash preparations were made and stained according to the method of Darlington and La Cour. Bromine acting for five minutes on the root-tips of Allium has a specific effect on the cell nucleus in the resting stage. The effects induced are shown thirty-six hours after treatment by spindle abnormalities in metaphase and anaphase, and result in polyploidy in a large number of cells. Bromine produces chromosome and chromatid fragmentation; the latter may be followed by reunion. The effect of the bromine is cumulative and depends on the time which elapses between treatment and fixation. The cytological effects induced by bromine strongly suggest that it is another specific mutafacient chemical.

  15. Effect of bromine substituents in the formation of PXDD from poly halogenated phenols

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, T.; Ohono, T.; Weber, R.

    2002-07-01

    The condensation of chlorophenols has been studied extensively in the last two decades and was discussed as one mechanism in particular for the formation of PCDD in thermal processes. Brominated flame retardants and brominated and brominated-chlorinated dibenzodioxins and dibenzofurans have received increased attention recently due to the growing use of brominated flame retardants during the last decade. This is resulting than increase of brominated compounds in waste (e.g. Electric and electronic shredder waste), containing a considerable amount of bromine, in the form of brominated flame retardants. Many studies reported on the formation of PBDD/PBDF from brominated diphenylethers, or bromophenosl. However with the exception of Sodhu et al, a comparison of the condensation behaviour of bromophenols and chlorophenols was not done. The condensation of brominated phenols is interesting from several aspects. Bromophenols are used as flame retardants and might be a source of PBDD/F during thermal stress. Bromophenols can also be generated during the combustion/pyrolysis of bromodiphenylether or tetrabromobisphenol A containing material, serving as potential precursors for the formation of PBDD/PBDF. Further, in municipal waste incinerators with sufficient secondary combustion, the largest amount of chlorinated aromatic compounds (PCDD, PCDF, PCBs, PCNs, and chlorophenols) are formed in the cooling section (boiler, duct, dust filtration). Therefore in combustion processes involving high concentrations of brominated flame retardants, mixed PXDD/PXDF might be formed by condensation reactions of precursors or de novo synthesis in the cooling zone. Therefore we investigated the condensation of abrominated phenol in more detail and compare it to the condensation reaction of the analogous chlorophenol. (Author)

  16. Algae form brominated organic compounds in surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Huetteroth, A.; Putschew, A.; Jekel, M. [Tech. Univ. Berlin (Germany)

    2004-09-15

    Monitoring of organic halogen compounds, measured as adsorbable organic bromine (AOBr) revealed seasonal high concentrations of organic bromine compounds in a surface water (Lake Tegel, Berlin, Germany). Usually, in late summer, concentrations are up to five times higher than during the rest of the year. The AOBr of the lake inflows (throughout the year less then 6 {mu}g/L) were always lower then those in the lake, which indicates a production of AOBr in the lake. A correlation of the AOBr and chlorophyll-a concentration (1) in the lake provides first evidence for the influence of phototrophic organisms. The knowledge of the natural production of organohalogens is relatively recent. Up to now there are more then 3800 identified natural organohalogen compounds that have been detected in marine plants, animals, and bacteria and also in terrestrial plants, fungi, lichen, bacteria, insects, some higher animals, and humans. Halogenated organic compounds are commonly considered to be of anthropogenic origin; derived from e.g. pharmaceuticals, herbicides, fungicides, insecticides, flame retardants, intermediates in organic synthesis and solvents. Additionally they are also produced as by-products during industrial processes and by waste water and drinking water disinfection. Organohalogen compounds may be toxic, persistent and/or carcinogenic. In order to understand the source and environmental relevance of naturally produced organobromine compounds in surface waters, the mechanism of the formation was investigated using batch tests with lake water and algae cultures.

  17. Impact of reactive bromine chemistry in the troposphere

    Directory of Open Access Journals (Sweden)

    R. von Glasow

    2004-01-01

    Full Text Available Recently several field campaigns and satellite observations have found strong indications for the presence of bromine oxide (BrO in the free troposphere. Using a global atmospheric chemistry transport model we show that BrO mixing ratios of a few tenths to 2 pmol mol-1 lead to a reduction in the zonal mean O3 mixing ratio of up to 18% in widespread areas and regionally up to 40% compared to a model run without bromine chemistry. A lower limit approach for the marine boundary layer, that does not explicitly include the release of halogens from sea salt aerosol, shows that for dimethyl sulfide (DMS the effect is even larger, with up to 60% reduction of its tropospheric column. This is accompanied by dramatic changes in DMS oxidation pathways, reducing its cooling effect on climate. In addition there are changes in the HO2:OH ratio that also affect NOx and PAN. These results imply that potentially significant strong sinks for O3 and DMS have so far been ignored in many studies of the chemistry of the troposphere.

  18. Maternal exposure to brominated flame retardants and infant Apgar scores.

    Science.gov (United States)

    Terrell, Metrecia L; Hartnett, Kathleen P; Lim, Hyeyeun; Wirth, Julie; Marcus, Michele

    2015-01-01

    Brominated flame retardants (BFRs) and other persistent organic pollutants have been associated with adverse health outcomes in humans and may be particularly toxic to the developing fetus. We investigated the association between in utero polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB) exposures and infant Apgar scores in a cohort of Michigan residents exposed to PBB through contaminated food after an industrial accident. PBB and PCB concentrations were measured in serum at the time the women were enrolled in the cohort. PBB concentrations were also estimated at the time of conception for each pregnancy using a validated elimination model. Apgar scores, a universal measure of infant health at birth, measured at 1 and 5min, were taken from birth certificates for 613 offspring born to 330 women. Maternal PCB concentrations at enrollment were not associated with below-median Apgar scores in this cohort. However, maternal PBB exposure was associated with a dose-related increase in the odds of a below-median Apgar score at 1min and 5min. Among infants whose mothers had an estimated PBB at conception above the limit of detection of 1 part per billion (ppb) to Apgar score increased with higher maternal PBB at conception. It remains critical that future studies examine possible relationships between in utero exposures to brominated compounds and adverse health outcomes.

  19. Simultaneous Determination of Multiple Sesquiterpenes in Curcuma wenyujin Herbal Medicines and Related Products with One Single Reference Standard

    Directory of Open Access Journals (Sweden)

    Zhi-Min Wang

    2013-02-01

    Full Text Available Some Curcuma species are widely used as herbal medicines. Sesquiterpenes are their important bioactive compounds and their quantitative analysis is generally accomplished by gas chromatography (GC or high performance liquid chromatography (HPLC, but the instability and high cost of some sesquiterpene reference standards have limited their application. It is necessary to find a practicable means to control the quality of herbal medicines. Using one stable component contained in Curcuma species to determine multiple analogues should be a practical option. In this study, a simple HPLC method for determination of sesquiterpenes using relative response factors (RRFs has been developed. The easily available and stable active component curdione was selected as the reference compound for calculating the RRFs of the other eight sesquiterpenes, including zedoarondiol (Zedo, isozedoarondiol (Isoz, aerugidiol (Aeru, (4S,5S-(+-germacrone-4,5-epoxide (Epox, curcumenone (Curc, neocurdione (Neoc, germacrone (Germ and furanodiene (Fura. Their RRFs against curdione were between 0.131–1.301, with a good reproducibility. By using the RRFs, the quantification of sesquiterpenes in Curcuma wenyujin herbal medicines and related products was carried out. The method is especially useful for the determination of (4S,5S-(+-germacrone-4,5-epoxide, curcumenone, germacrone and furanodiene, which often are regarded as the principle components in Curcuma species, but unstable when were purified. It is an ideal means to analyze the components for which reference standards are not readily available.

  20. Simultaneous determination of multiple sesquiterpenes in Curcuma wenyujin herbal medicines and related products with one single reference standard.

    Science.gov (United States)

    Zhu, Jing-Jing; An, Yue-Wei; Hu, Guang; Yin, Guo-Ping; Zhang, Qi-Wei; Wang, Zhi-Min

    2013-02-06

    Some Curcuma species are widely used as herbal medicines. Sesquiterpenes are their important bioactive compounds and their quantitative analysis is generally accomplished by gas chromatography (GC) or high performance liquid chromatography (HPLC), but the instability and high cost of some sesquiterpene reference standards have limited their application. It is necessary to find a practicable means to control the quality of herbal medicines. Using one stable component contained in Curcuma species to determine multiple analogues should be a practical option. In this study, a simple HPLC method for determination of sesquiterpenes using relative response factors (RRFs) has been developed. The easily available and stable active component curdione was selected as the reference compound for calculating the RRFs of the other eight sesquiterpenes, including zedoarondiol (Zedo), isozedoarondiol (Isoz), aerugidiol (Aeru), (4S,5S)-(+)-germacrone-4,5-epoxide (Epox), curcumenone (Curc), neocurdione (Neoc), germacrone (Germ) and furanodiene (Fura). Their RRFs against curdione were between 0.131-1.301, with a good reproducibility. By using the RRFs, the quantification of sesquiterpenes in Curcuma wenyujin herbal medicines and related products was carried out. The method is especially useful for the determination of (4S,5S)-(+)-germacrone-4,5-epoxide, curcumenone, germacrone and furanodiene, which often are regarded as the principle components in Curcuma species, but unstable when were purified. It is an ideal means to analyze the components for which reference standards are not readily available.

  1. Quorum sensing inhibitory potential and molecular docking studies of sesquiterpene lactones from Vernonia blumeoides.

    Science.gov (United States)

    Aliyu, Abubakar Babando; Koorbanally, Neil Anthony; Moodley, Brenda; Singh, Parvesh; Chenia, Hafizah Yousuf

    2016-06-01

    The increasing incidence of multidrug-resistant Gram-negative bacterial pathogens has focused research on the suppression of bacterial virulence via quorum sensing inhibition strategies, rather than the conventional antimicrobial approach. The anti-virulence potential of eudesmanolide sesquiterpene lactones previously isolated from Vernonia blumeoides was assessed by inhibition of quorum sensing and in silico molecular docking. Inhibition of quorum sensing-controlled violacein production in Chromobacterium violaceum was quantified using violacein inhibition assays. Qualitative modulation of quorum sensing activity and signal synthesis was investigated using agar diffusion double ring assays and C. violaceum and Agrobacterium tumefaciens biosensor systems. Inhibition of violacein production was concentration-dependent, with ⩾90% inhibition being obtained with ⩾2.4 mg ml(-1) of crude extracts. Violacein inhibition was significant for the ethyl acetate extract with decreasing inhibition being observed with dichloromethane, hexane and methanol extracts. Violacein inhibition ⩾80% was obtained with 0.071 mg ml(-1) of blumeoidolide B in comparison with ⩾3.6 mg ml(-1) of blumeoidolide A. Agar diffusion double ring assays indicated that only the activity of the LuxI synthase homologue, CviI, was modulated by blumeoidolides A and B, and V. blumeoides crude extracts, suggesting that quorum sensing signal synthesis was down-regulated or competitively inhibited. Finally, molecular docking was conducted to explore the binding conformations of sesquiterpene lactones into the binding sites of quorum sensing regulator proteins, CviR and CviR'. The computed binding energy data suggested that the blumeoidolides have a tendency to inhibit both CviR and CviR' with varying binding affinities. Vernonia eudesmanolide sesquiterpene lactones have the potential to be novel therapeutic agents, which might be important in reducing virulence and pathogenicity of drug-resistant bacteria

  2. Bromine Chemistry in the Tropical UTLS during the 2011, 2013 and 2014 ATTREX Experiments

    Science.gov (United States)

    Werner, Bodo; Stutz, Jochen; Spolaor, Max; Festa, James; Tsai, Catalina; Colosimo, Fedele; Cheung, Ross; Deutschmann, Tim; Raecke, Rasmus; Scalone, Lisa; Tricoli, Ugo; Pfeilsticker, Klaus; Navarro, Maria; Atlas, Elliot; Chipperfield, Martyn; Hossaini, Ryan

    2015-04-01

    Bromine plays an important role for the chemistry of ozone in the stratosphere and upper troposphere. An accurate quantitative understanding of the sources, sinks, and chemical transformation of bromine species is thus important to understand the bromine budget in the upper troposphere and lower stratosphere (UTLS), which also serves as a gate to the stratosphere. Vertical transport of very short-lived organic bromine precursors and inorganic product gases has been identified as the main source of bromine in the UTLS. However, the contribution of inorganic vs. organic compounds is not well quantified, particularly in the tropical UTLS. A limb scanning Differential Optical Absorption Spectroscopy instrument was deployed onboard NASA's UAV Global Hawk during the NASA Airborne Tropical TRopopause EXperiment (ATTREX) during a series of flights into the eastern and western Pacific tropopause layer (flight altitudes up to 18 km), which is a gateway to the stratosphere. The measurement methodology to retrieve vertical trace gas concentration profiles will be briefly presented. Observations of BrO, NO2 and O3 and of other trace species, in particular of brominated hydrocarbons are compared with simulations of the SLIMCAT CTM and interpreted with respect to photochemistry and the budget of bromine within the tropical tropopause layer (TTL).

  3. Conversion of bromine during thermal decomposition of printed circuit boards at high temperature.

    Science.gov (United States)

    Jin, Yu-qi; Tao, Lin; Chi, Yong; Yan, Jian-hua

    2011-02-15

    The conversion of bromine during the thermal decomposition of printed circuit boards (PCBs) was investigated at isothermal temperatures ranging from 800°C to 1100°C by using a quartz tube furnace. The influence of temperature, oxygen concentrations (0%, 10% and 21% in the nitrogen-oxygen atmosphere) and content of steam on conversion of bromine was studied. With the increment of temperature, the conversion from organic bromine in the PCBs to inorganic bromine in the gaseous fraction increased from 69.0% to 96.4%. The bromine was mainly evolved as HBr and Br(2) in oxidizing condition and the Br(2)/HBr mass ratio increased at stronger oxidizing atmosphere. The experimental results also indicated that the existence of steam can reduce the formation of Br(2). Furthermore, co-combustion of PCBs with S and CaO, both as addition agents, was investigated, respectively. In the presence of SO(2), Br(2)/HBr mass ratio obviously decreased. Moreover, the utilization of calcium oxide can efficiently promote the conversion of organic bromine to inorganic bromine. According to the experimental results, incinerating PCBs at high temperature can efficiently destroy the organobrominated compounds that are considered to be possible precursors of polybrominated dibenzeo-p-dioxins and dibenzofurans (PBDD/Fs), but the Br(2) and HBr in flue gas should be efficiently controlled.

  4. Cyclization of farnesyl pyrophosphate to the sesquiterpene olefins humulene and caryophyllene by an enzyme system from sage (Salvia officinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, R.; Gundy, A.

    1984-09-01

    A soluble enzyme preparation obtained from sage (Salvia officinalis) leaves was shown to catalyze the divalent metal-ion dependent cyclization of trans, trans-farnesyl pyrophosphate to the macrocyclic sesquiterpene olefins humulene and caryophyllene. The identities of the biosynthetic products were confirmed by radiochromatographic analysis and by preparation of crystalline derivatives, and the specificity of labeling in the cyclization reaction was established by chemical degradation of the olefins derived enzymatically from (1-3H2)farnesyl pyrophosphate. These results constitute the first report on the cyclization of farnesyl pyrophosphate to humulene and caryophyllene, two of the most common sesquiterpenes in nature, and the first description of a soluble sesquiterpene cyclase to be isolated from leaves of a higher plant.

  5. Cadinane sesquiterpenes from Curcuma phaeocaulis with their inhibitory activities on nitric oxide production in RAW 264.7 cells.

    Science.gov (United States)

    Ma, Jianghao; Wang, Ying; Liu, Yue; Gao, Suyu; Ding, Liqin; Zhao, Feng; Chen, Lixia; Qiu, Feng

    2015-06-01

    Four new cadinane-type sesquiterpenes named phacadinanes A-D (1-4) were isolated from the rhizomes of Curcuma phaeocaulis. Their structures were elucidated by 1D and 2D NMR, as well as accurate mass measurements. Compound 4 was the first example of a rare 4,5-seco-cadinane sesquiterpene isolated from the Zingiberaceae family. Furthermore, inhibitory effects of the isolated compounds on nitric oxide production in LPS-activated macrophages were evaluated. Compounds 1 and 2 showed strong inhibitory activities on NO production with IC50 values of 3.88±0.58 and 2.25±0.71 μM, respectively. A possible biogenetic pathway for 4,5-seco-cadinane sesquiterpene (4) was postulated.

  6. Tandem Mass Spectrometry for Structural Identification of Sesquiterpene alkaloids from the stems of dendrobium nobile using LC-QToF3

    Science.gov (United States)

    Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine (TCM). Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chroma...

  7. HIGH PERFORMANCE LIQUID CHROMATOGRAPHY USE IN ANALYSIS OF SESQUITERPENIC LACTONES OF LAURUS NOBILIS

    Directory of Open Access Journals (Sweden)

    S. P. Senchenko

    2015-01-01

    Full Text Available We have developed a methodology of quantitative determination of sesquiterpenic lactones (costunolide and dehydrocostuslactone in leaves of Laurus nobilis using reversed phase HPLC. We have determined optimal conditions for the substances under study extraction from active parts. Using the developed methods we have established that costunolide and dehydrocostuslactone content in Laurus nobilis samples in terms of absolutely dry active parts is 0.99 and 0.26% correspondingly.

  8. Alkaloids and Sesquiterpenes from the South China Sea Gorgonian Echinogorgia pseudossapo

    Directory of Open Access Journals (Sweden)

    Shu-Hua Qi

    2011-11-01

    Full Text Available Five zoanthoxanthin alkaloids (1–5 and four sesquiterpenes (6–9 were isolated from the South China Sea gorgonian Echinogorgia pseudossapo. Their structures were determined on the bases of extensive spectroscopic analyses, including 1D and 2D NMR data. Among them, pseudozoanthoxanthins III and IV (1–2, 8-hydroxy-6β-methoxy-14-oxooplop-6,12-olide (6 and 3β-methoxyguaian-10(14-en-2β-ol (7 were new, 1 and 3 showed mild anti-HSV-1 activity, and 7 showed significant antilarval activity towards Balanus amphitrite larvae.

  9. Two minor diterpene glycosides and an eudesman sesquiterpene from Coleus forskohlii.

    Science.gov (United States)

    Shan, Yupei; Wang, Xiaobing; Zhou, Xiang; Kong, Lingyi; Niwa, Masatake

    2007-03-01

    Two new labdane diterpene glycosides, forskoditerpenosides A, B (1, 2) and a new eudesmane sesquiterpene, 4beta,7beta,11-enantioeudesmantriol (3), were isolated from the ethanol extract of the whole plant of Coleus forskohlii. Their structures and stereochemistry were elucidated by extensive spectroscopic analysis and chemical methods. The structure of compound 3 was confirmed by X-ray diffraction. This is the first report about the occurrence of glycosides derived from the kind of labdane diterpene, 8,13-epoxy-labd-14-en-11-one, in the nature. Compounds 1 and 2 showed relaxative effects on isolated guinea pig tracheal spirals in vitro.

  10. Characterization of a New Sesquiterpene and Antifungal Activities of Chemical Constituents from Dryopteris fragrans (L. Schott

    Directory of Open Access Journals (Sweden)

    Yu-Hong Huang

    2014-01-01

    Full Text Available One new sesquiterpene and six known compounds were isolated from Dryopteris fragrans (L. Schot. They were identified as 3-O-β-D-glucopyranosylalbicanol- 11-O-β-D-glucopyranoside (1, dihydroconiferylalcohol (2, (E-3-(4-hydroxyphenylacrylic acid (3, esculetin (4, 5,7-dihydroxy-2-hydroxymethylchromone (5, eriodictyol (6 and isoorientin (7 by UV, MS, 1D-NMR and 2D-NMR spectroscopy. The antifungal activities of the seven isolated compounds were screened. Compounds 2, 3, 4 and 5 showed obvious activities against Microsporum canis and Epidermophyton floccosum.

  11. Phytochemical investigation of sesquiterpenes from the fruits of Schisandra chinensis and their cytotoxic activity.

    Science.gov (United States)

    Venkanna, A; Siva, B; Poornima, B; Vadaparthi, P R Rao; Prasad, K Rajendra; Reddy, K Ashok; Reddy, G Bhanu Prakash; Babu, K Suresh

    2014-06-01

    Phytochemical investigation of ethanolic extract from the fruits of Schisandra chinensis led to the isolation of four new sesquiterpenes (1-4); their structures were determined by a combination of NMR (1D and 2D) and MS spectroscopic techniques. In addition, all these isolates were screened for their cytotoxic activities against MCF-7, Caco-2, Hela, Lncap, Hep G2 and MDA-MB231 cancer cell lines. Results indicated that compounds 2 and 3 displayed potent cytotoxic activity against Caco2 cell lines with IC50 values of 17.10 μg/mM and 16.46 μg/mM, respectively.

  12. A new sesquiterpene lactone and a new aromatic glycoside from Illicium difengpi

    Directory of Open Access Journals (Sweden)

    Lei Fang

    2011-10-01

    Full Text Available A new sesquiterpene lactone (1 and a new aromatic glycoside (2, together with three known compounds (3–5 were isolated from the stem bark of Illicium difengpi K. I. B et K. I. M. Their structures were determined by spectroscopic methods, including 1D and 2D NMR, HRESIMS, and chemical methods. The absolute configuration of the secondary alcohol in 1 was confirmed by Mosher's method. Compound 2 exhibited significant anti-inflammatory activity with IC50 value of 6.72 μmol/L.

  13. Five new cadinane-type sesquiterpenes from the heartwood of Chamaecyparis obtusa var. formosana.

    Science.gov (United States)

    Kuo, Yueh-Hsiung; Chen, Chia-Hsien; Chien, Shih-Chang; Lin, Yun-Lian

    2002-01-01

    Muurola-4,10(14)-dien-3-one (1), 10-O-acetyl-15-oxo-alpha-cadinol (2), 15-hydroxy-alpha-cadinol (3), 4alpha-hydroxy-5beta-ethoxy-epi-cubenol (4), and 4alpha-hydroxy-5beta-acetoxy-epi-cubenol (5), five new bicyclic sesquiterpenes, have been isolated from the heartwood of Chamaecyparis obtusa var. formosana along with the known compounds epi-cubenol, T-cadinol, T-muurolol, delta-cadinol, and alpha-cadinol. The structures of the new constituents were elucidated through chemical and spectral studies.

  14. Flavonoids and sesquiterpenes of Croton pedicellatus Kunth; Flavonoides e sesquiterpenos de Croton pedicellatus Kunth.

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Elton Luz; Andrade Neto, Manoel; Silveira, Edilberto Rocha; Pessoa, Otilia Deusdenia Loiola [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil). Dept. de Quimica

    2012-07-01

    The chemical investigation of the ethanolic extract from leaves of Croton pedicellatus yielded the bis-nor-sesquiterpenes blumenol A and blumenol A glucoside, along with the flavonoids: tiliroside, 6{sup -}O-p-coumaroyl-{beta}-galactopyranosyl- kaempferol, 6{sup -}O-p-coumaroyl-{beta}-glucopyranosyl-3{sup -}methoxy- kaempferol, kaempferol, 3-glucopyranosyl-quercetin and alpinumisoflavone, as well as 4-hydroxy-3,5-dimethoxybenzoic acid. The identification of all isolated compounds was performed by spectrometric methods, including HR-ESI-MS, 1D and 2D NMR experiments, and by comparison with previously-described physical and spectral data. (author)

  15. The contribution of anthropogenic bromine emissions to past stratospheric ozone trends: a modelling study

    Directory of Open Access Journals (Sweden)

    B.-M. Sinnhuber

    2009-04-01

    Full Text Available Bromine compounds play an important role in the depletion of stratospheric ozone. We have calculated the changes in stratospheric ozone in response to changes in the halogen loading over the past decades, using a two-dimensional (latitude/height model constrained by source gas mixing ratios at the surface. Model calculations of the decrease of total column ozone since 1980 agree reasonably well with observed ozone trends, in particular when the contribution from very short-lived bromine compounds is included. Model calculations with bromine source gas mixing ratios fixed at 1959 levels, corresponding approximately to a situation with no anthropogenic bromine emissions, show an ozone column reduction between 1980 and 2005 at Northern Hemisphere mid-latitudes of only ≈55% compared to a model run including all halogen source gases. In this sense anthropogenic bromine emissions are responsible for ≈45% of the model estimated column ozone loss at Northern Hemisphere mid-latitudes. However, since a large fraction of the bromine induced ozone loss is due to the combined BrO/ClO catalytic cycle, the effect of bromine would have been smaller in the absence of anthropogenic chlorine emissions. The chemical efficiency of bromine relative to chlorine for global total ozone depletion from our model calculations, expressed by the so called α-factor, is 64 on an annual average. This value is much higher than previously published results. Updates in reaction rate constants can explain only part of the differences in α. The inclusion of bromine from very short-lived source gases has only a minor effect on the global mean α-factor.

  16. Brominated lipids identify lipid binding sites on the surface of the reaction center from Rhodobacter sphaeroides.

    Science.gov (United States)

    Roszak, Aleksander W; Gardiner, Alastair T; Isaacs, Neil W; Cogdell, Richard J

    2007-03-20

    This study describes the use of brominated phospholipids to distinguish between lipid and detergent binding sites on the surface of a typical alpha-helical membrane protein. Reaction centers isolated from Rhodobacter sphaeroides were cocrystallized with added brominated phospholipids. X-ray structural analysis of these crystals has revealed the presence of two lipid binding sites from the characteristic strong X-ray scattering from the bromine atoms. These results demonstrate the usefulness of this approach to mapping lipid binding sites at the surface of membrane proteins.

  17. Influence of Main Components in Exhaust Gas on Mercury Adsorption Capacity of Brominated Activated Carbon

    Directory of Open Access Journals (Sweden)

    Tran Hong Con

    2016-01-01

    Full Text Available Brominated activated carbon (AC-Br, which was produced from coconut shell activated carbon (AC and brominated by wet way with elemental bromine, was determined as a material with super high adsorption capacity of mercury vapor. But in real exhaust gases, there are many components such as SO2, NOx, CO, CO2, HCl, H2O can influence on adsorption ability of the AC-Br. In this paper, these influences were studied and compared them between initial AC and AC-Br. Each component has different effect on AC and AC-Br and followed by its particular mechanism.

  18. Drimane Sesquiterpene-Conjugated Amino Acids from a Marine Isolate of the Fungus Talaromyces minioluteus (Penicillium Minioluteum

    Directory of Open Access Journals (Sweden)

    Suthatip Ngokpol

    2015-06-01

    Full Text Available Four new sesquiterpene lactones (3, 4, 6 and 7 and three known compounds, purpuride (1, berkedrimane B (2 and purpuride B (5, were isolated from the marine fungus, Talaromyces minioluteus (Penicillium minioluteum. New compounds were drimane sesquiterpenes conjugated with N-acetyl-l-valine, and their structures were elucidated by analysis of spectroscopic data, as well as by single crystal X-ray analysis. The isolated compounds could not inhibit the apoptosis-regulating enzyme, caspase-3, while three of the compounds (2, 3 and 7 exhibited weak cytotoxic activity.

  19. Selective nitration and bromination of surprisingly ruffled phosphorus corroles.

    Science.gov (United States)

    Pomarico, Giuseppe; Tortora, Luca; Fronczek, Frank R; Smith, Kevin M; Paolesse, Roberto

    2016-05-01

    Phosphorus complexes of corrole have recently attracted increasing interest since these compounds can be easily prepared in good yields, are stable, and show unusual optical properties. For these reasons, phosphorus corroles represent a class of interesting compounds to be exploited in the field of material science or for biomedical investigations and the definition of synthetic pathways for their functionalization is an important step to optimize their properties for various applications. We report here the reactivity of the phosphorus complex of 5,10,15-tritolylcorrole in the nitration or bromination reaction. Both these attempts were successful, allowing the preparation of substituted phosphorus corroles, which can be used as intermediates of more complex architectures endowed with useful properties. Furthermore, the crystallographic characterization of both complexes shows that they have an unusual ruffled geometry of the corrole core, a conformation that has not been considered possible for such a macrocycle.

  20. Diamagnetic Raman Optical Activity of Chlorine, Bromine, and Iodine Gases.

    Science.gov (United States)

    Šebestík, Jaroslav; Kapitán, Josef; Pačes, Ondřej; Bouř, Petr

    2016-03-01

    Magnetic Raman optical activity of gases provides unique information about their electric and magnetic properties. Magnetic Raman optical activity has recently been observed in a paramagnetic gas (Angew. Chem. Int. Ed. 2012, 51, 11058; Angew. Chem. 2012, 124, 11220). In diamagnetic molecules, it has been considered too weak to be measurable. However, in chlorine, bromine and iodine vapors, we could detect a significant signal as well. Zeeman splitting of electronic ground-state energy levels cannot rationalize the observed circular intensity difference (CID) values of about 10(-4). These are explicable by participation of paramagnetic excited electronic states. Then a simple model including one electronic excited state provides reasonable spectral intensities. The results suggest that this kind of scattering by diamagnetic molecules is a general event observable under resonance conditions. The phenomenon sheds new light on the role of excited states in the Raman scattering, and may be used to probe molecular geometry and electronic structure.

  1. The third international interlaboratory study on brominated flame retardants

    Energy Technology Data Exchange (ETDEWEB)

    Boer, J. de [Netherlands Institute for Fisheries Research, IJmuiden (Netherlands); Wells, D. [FRS Marine Laboratory, Aberdeen (United Kingdom)

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs) have been produced as brominated flame retardants (BFRs) since the early 1970s and have been found in the aquatic environment since the late 1970s. However, as a result of their detection in sperm whales from deeper Atlantic waters and in human milk, many laboratories are now measuring PBDEs in environmental samples. A first international interlaboratory study (ILS) on the analysis of PBDEs, organised by the Bromine Science and Environmental Forum (BSEF), Brussels, Belgium, in collaboration with the Netherlands Institute for Fisheries Research (RIVO) was conducted in 1999-2000. The results showed that the 18 participating laboratories produced comparable results for BDE 47 in various matrices but had analytical difficulties for other BDEs, in particular for the BDEs 99 and 209. A second study was organised in 2001-2002 by BSEF, QUASIMEME and RIVO. That study showed improvement in comparability of the participating laboratories for BDE99 and some other BDEs. However, there was no improvement for BDE209. Hexabromocyclododecane (HBCD), tetrabromobisphenol-A (TBBP-A) and the dimethyl derivative of TBBP-A (dimethyl TBBP-A) were included in the second study. However, it appeared that only two or three laboratories were able to analyse these determinands. Others laboratories were still in the development phase with their methods for these BFRs. This third study was organised as a development exercise by QUASIMEME, in collaboration with RIVO between September and December 2003. The BFRs selected were the same as in the second study. Two biota test materials, a harbor sediment, a sewage sludge, and two standard solutions were dispatched to the participants.

  2. Sesquiterpenes from the seeds of Guarea guidonia (Meliaceae); Sesquiterpenos de sementes de Guarea guidonia (Meliaceae)

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Luzinatia Ramos [Departamento de Quimica, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil); Silva, Alene Cortes de Queiroz e; Freire, Talita Vilalva; Garcez, Fernanda Rodrigues; Garcez, Walmir Silva [Departamento de Quimica, Universidade Federal de Mato Grosso do Sul, Campo Grande, MS (Brazil)

    2012-07-01

    Two new sesquiterpenes 6{alpha}-ethoxyeudesm-4(15)-en-1{beta}-ol (1) and (7R{sup *})-5-epi-opposit-4(15)-ene-1{beta},7-diol (7) were isolated from the seeds of a specimen of Guarea guidonia (Meliaceae). Five other known sesquiterpenes, eudesm-4(15)-ene-1{beta},6a-diol (2), 5-epi-eudesm-4(15)-ene-1{beta},6{beta}-diol (3), eudesm-4(15)-ene-1{beta},5a-diol (4), eudesm-4(15),7-dien-1{beta}-ol (5) and (7R{sup *})-opposit-4(15)-ene-1{beta},7-diol (6), were also isolated in this work. Their structures were determined on the basis of spectral data (MS, IR, and NMR-1D and 2D) and subsequent comparisons with the literature. The substances 3, 4 and 6 are reported for the first time in Meliaceae and 5 for the first time in the genus Guarea. (author)

  3. Galbanic acid, a cytotoxic sesquiterpene from the gum resin of Ferula asafoetida, blocks protein farnesyltransferase.

    Science.gov (United States)

    Cha, Mi-Ran; Choi, Yeon Hee; Choi, Chun Whan; Kim, Young Sup; Kim, Young-Kyoon; Ryu, Shi Yong; Kim, Young Ho; Choi, Sang Un

    2011-01-01

    Farnesylation of the activated RAS oncogene product by protein farnesyltransferase (FTase) is a critical step for its oncogenic function. Bioassay-guided purification of Ferula asafoetida (Umbelliferae) extract led to the isolation of the coumarin-derived sesquiterpene galbanic acid (1) as an active principal for FTase inhibitory activity, together with the four structurally related sesquiterpenes karatavicinol (2), umbelliprenin (3), farnesiferol B (4), and farnesiferol C (5). The 50 % inhibitory concentration (IC (50)) of 1 against FTase in an enzyme-based assay was calculated as 2.5 µM. Compound 1 also demonstrated potent inhibition of the proliferation of oncogenic RAS-transformed NIH3T3/Hras-F in a dose-dependent manner. The IC (50) value of 1 on the proliferation of oncogenic RAS-transformed NIH3T3/Hras-F cells was calculated as 16.2 µM, whereas its IC (50) value on control vector-transfected normal RAS-containing NIH3T3/ZIPneo cells was 58.5 µM.

  4. Monoterpene and sesquiterpene emissions of three Mediterranean species through calcareous and siliceous soils in natural conditions

    Science.gov (United States)

    Ormeño, E.; Fernandez, C.; Bousquet-Mélou, A.; Greff, S.; Morin, E.; Robles, C.; Vila, B.; Bonin, G.

    Little is known about terpene emissions released by plants in response to abiotic factors, except for climate-related factors. Standard emissions ( ES) of monoterpenes ( ESM) and sesquiterpenes ( ESS) of Rosmarinus officinalis, Pinus halepensis and Cistus albidus in siliceous and calcareous sites were examined. Their dependency on some nutrients in these soils was also analyzed. The study was carried out in the south of France at the end of March, when C. albidus exhibited a leaf growth state, while the other two species exhibited a pre-budbreak state. The results revealed that ES of all major monoterpenes released by R. officinalis and ES of α-pinene and α-humulene of P. halepensis were higher in plants growing in calcareous soils. In contrast, for C. albidus, ESM and ES of β-bourbonene and α-humulene were higher in siliceous soils. ESM of all species was mainly correlated with nitrogen ( N) and available phosphorous (P A), while dependency on Ca 2+ or K + was variable. None of these nutrients was significantly correlated with ESS, suggesting that sesquiterpene synthesis pathway requires different nutrient supplies. While higher soil nutrient content stimulated ESM of R. officinalis and P. halepensis, it had a negative effect on ESM of C. albidus, probably because C. albidus exhibited a different phenological state. Considering the soil nature, and particularly N and P A as inputs in plant terpene inventories could hence contribute to obtain more accurate terpene estimates.

  5. Enhancing sesquiterpene production in Saccharomyces cerevisiae through in silico driven metabolic engineering.

    Science.gov (United States)

    Asadollahi, Mohammad A; Maury, Jérôme; Patil, Kiran Raosaheb; Schalk, Michel; Clark, Anthony; Nielsen, Jens

    2009-11-01

    A genome-scale metabolic model was used to identify new target genes for enhanced biosynthesis of sesquiterpenes in the yeast Saccharomyces cerevisiae. The effect of gene deletions on the flux distributions in the metabolic model of S. cerevisiae was assessed using OptGene as the modeling framework and minimization of metabolic adjustments (MOMA) as objective function. Deletion of NADPH-dependent glutamate dehydrogenase encoded by GDH1 was identified as the best target gene for the improvement of sesquiterpene biosynthesis in yeast. Deletion of this gene enhances the available NADPH in the cytosol for other NADPH requiring enzymes, including HMG-CoA reductase. However, since disruption of GDH1 impairs the ammonia utilization, simultaneous over-expression of the NADH-dependent glutamate dehydrogenase encoded by GDH2 was also considered in this study. Deletion of GDH1 led to an approximately 85% increase in the final cubebol titer. However, deletion of this gene also caused a significant decrease in the maximum specific growth rate. Over-expression of GDH2 did not show a further effect on the final cubebol titer but this alteration significantly improved the growth rate compared to the GDH1 deleted strain.

  6. Heliolactone, a non-sesquiterpene lactone germination stimulant for root parasitic weeds from sunflower.

    Science.gov (United States)

    Ueno, Kotomi; Furumoto, Toshio; Umeda, Shuhei; Mizutani, Masaharu; Takikawa, Hirosato; Batchvarova, Rossitza; Sugimoto, Yukihiro

    2014-12-01

    Root exudates of sunflower (Helianthus annuus L.) line 2607A induced germination of seeds of root parasitic weeds Striga hermonthica, Orobanche cumana, Orobanche minor, Orobanche crenata, and Phelipanche aegyptiaca. Bioassay-guided purification led to the isolation of a germination stimulant designated as heliolactone. FT-MS analysis indicated a molecular formula of C20H24O6. Detailed NMR spectroscopic studies established a methylfuranone group, a common structural component of strigolactones connected to a methyl ester of a C14 carboxylic acid via an enol ether bridge. The cyclohexenone ring is identical to that of 3-oxo-α-ionol and the other part of the molecule corresponds to an oxidized carlactone at C-19. It is a carlactone-type molecule and functions as a germination stimulant for seeds of root parasitic weeds. Heliolactone induced seed germination of the above mentioned root parasitic weeds, while dehydrocostus lactone and costunolide, sesquiterpene lactones isolated from sunflower root exudates, were effective only on O. cumana and O. minor. Heliolactone production in aquacultures increased when sunflower seedlings were grown hydroponically in tap water and decreased on supplementation of the culture with either phosphorus or nitrogen. Costunolide, on the other hand, was detected at a higher concentration in well-nourished medium as opposed to nutrient-deficient media, thus suggesting a contrasting contribution of heliolactone and the sesquiterpene lactone to the germination of O. cumana under different soil fertility levels.

  7. Micellar LC Separation of Sesquiterpenic Acids and Their Determination in Valeriana officinalis L. Root and Extracts

    Directory of Open Access Journals (Sweden)

    Artem U. Kulikov

    2012-01-01

    Full Text Available A simple micellar liquid chromatography (MLC method was developed and validated according to ICH Guidelines for the determination of sesquiterpenic acids (valerenic, hydroxyvalerenic, and acetoxyvalerenic acids in root and rhizome extract from Valeriana officinalis L. and valerian dry hydroalcoholic extract. Samples were analyzed on Nucleosil C18 column (150mm×4.6mm, 5 μm using an isocratic mobile phase which consisted of Brij 35 (5% (w/v aqueous solution; pH 2.3±0.1 by phosphoric acid and 1-butanol (6% (v/v; UV detection was at 220 nm. Micellar mobile phase using allows to fully separate valerenic acids within 25 minutes. Linearity for hydroxyvalerenic, acetoxyvalerenic, and valerenic acids was 1.9–27.9, 4.2–63.0, and 6.1–91·3 μg.mL−1, and limit of detection was 0.14, 0.037, and 0.09 μg·mL−1, respectively. Intraday and interday precisions were not less than 2% for all investigated compounds. The proposed method was found to be reproducible and convenient for quantitative analysis of sesquiterpenic acids in valerian root and related preparations.

  8. Fumigant and repellent properties of sesquiterpene-rich essential oil from Teucrium polium subsp. capitatum (L.)

    Institute of Scientific and Technical Information of China (English)

    Abbas Khani; Monireh Heydarian

    2014-01-01

    Objective:To test fumigant and repellent properties of sesquiterpene-rich essential oil from Teucrium polium subsp.capitatum(L.).Methods:The fumigant toxicity test was performed at(27±1)℃,(65±5)% relative humidity, and under darkness condition and24 h exposure time.The chemical composition of the isolated oils was examined by gas chromatography-mass spectrometry.Results:The major compounds wereα-cadinol(46.2%), caryophyllene oxide(25.9%), α muurolol epi(8.1%), cadalene(3.7%) and longiverbenone(2.9%).In all cases, considerable differences in mortality of insect to essential oil vapor were observed in different concentrations and exposure times.Callosobruchus maculatus(C. maculates)(LC50=148.9 μL/L air) was more susceptible to the tested plant product thanTeucrium castaneum(T. castaneum) (LC50=360.2 μL/L air) based onLC50 values.In the present investigation, the concentration of3 μL /mL acetone showed60% and52% repellency againstT. casteneumandC. maculatus adults, respectively.Conclusions:The results suggests that sesquiterpene-rich essential oils from the tested plant could be used as a potential control agent for stored-product insects.

  9. Antiviral and antimicrobial activities of three sesquiterpene lactones from Centaurea solstitialis L. ssp. solstitialis.

    Science.gov (United States)

    Ozçelik, Berrin; Gürbüz, Ilhan; Karaoglu, Taner; Yeşilada, Erdem

    2009-01-01

    Three sesquiterpene lactones (centaurepensin = chlorohyssopifolin A, chlorojanerin and 13-acetyl solstitialin A) isolated from the aerial parts of Centaurea solstitialis L. ssp. solstitialis (Asteraceae) were investigated for antimicrobial and antiviral activities. For the antimicrobial activity assessment, both standard and isolated strains of Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, Candida albicans and C. parapsilosis were employed by the microdilution method. Herpes simplex type-1, a DNA virus, and Parainfluenza, an RNA virus, were employed for the determination of the antiviral activity of these three sesquiterpene lactones using Vero cell lines. Ampicilline, ofloxocine, ketoconazole, fluconazole, acyclovir and oseltamivir were used as the reference drugs. 13-Acetyl solstitialin A displayed remarkable antibacterial activity against isolated strains of E. faecalis at 1 microg/ml concentration, which was close to the effective concentrations of ampicillin. The same compound also showed significant activity against the DNA virus, being as potent as the reference compound acyclovir at maximum and minimum concentrations of 16-<0.00006 microg/ml. This is the first report showing that 13-acetyl solstitialin A possesses significant antiviral activity.

  10. Potent competitive interactions of some brominated flame retardants and related compounds with human transthyretin in vitro

    NARCIS (Netherlands)

    Meerts, I.A.T.M.; Zanden, van J.J.; Luijks, E.A.C.; Leeuwen-Bol, van I.; Marsh, G.; Jakobsson, E.; Bergman, A.; Brouwer, A.

    2000-01-01

    Brominated flame retardants such as polybrominated diphenyl ethers (PBDEs), pentabromophenol (PBP), and tetrabromobisphenol A (TBBPA) are produced in large quantities for use in electronic equipment, plastics, and building materials. Because these compounds have some structural resemblance to the th

  11. Oxidation of mercury by bromine in the subtropical Pacific free troposphere

    Science.gov (United States)

    Gratz, L. E.; Ambrose, J. L.; Jaffe, D. A.; Shah, V.; Jaeglé, L.; Stutz, J.; Festa, J.; Spolaor, M.; Tsai, C.; Selin, N. E.; Song, S.; Zhou, X.; Weinheimer, A. J.; Knapp, D. J.; Montzka, D. D.; Flocke, F. M.; Campos, T. L.; Apel, E.; Hornbrook, R.; Blake, N. J.; Hall, S.; Tyndall, G. S.; Reeves, M.; Stechman, D.; Stell, M.

    2015-12-01

    Mercury is a global toxin that can be introduced to ecosystems through atmospheric deposition. Mercury oxidation is thought to occur in the free troposphere by bromine radicals, but direct observational evidence for this process is currently unavailable. During the 2013 Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks campaign, we measured enhanced oxidized mercury and bromine monoxide in a free tropospheric air mass over Texas. We use trace gas measurements, air mass back trajectories, and a chemical box model to confirm the origin and chemical history of the sampled air mass. We find the presence of elevated oxidized mercury to be consistent with oxidation of elemental mercury by bromine atoms in this subsiding upper tropospheric air mass within the subtropical Pacific High, where dry atmospheric conditions are conducive to oxidized mercury accumulation. Our results support the role of bromine as the dominant oxidant of mercury in the upper troposphere.

  12. Potent anti-inflammatory activity of novel microtubule-modulating brominated noscapine analogs.

    Science.gov (United States)

    Zughaier, Susu; Karna, Prasanthi; Stephens, David; Aneja, Ritu

    2010-02-11

    Noscapine, a plant-derived, non-toxic, over-the-counter antitussive alkaloid has tubulin-binding properties. Based upon the structural resemblance of noscapine to colchicine, a tubulin-binding anti-inflammatory drug, noscapine and its semi-synthetic brominated analogs were examined for in vitro anti-inflammatory activity. Brominated noscapine analogs were found to inhibit cytokine and chemokine release from macrophage cell lines but did not affect cell viability. Brominated noscapine analogs demonstrated anti-inflammatory properties in both TLR- and non-TLR induced in vitro innate immune pathway inflammation models, mimicking septic and sterile infection respectively. In addition, electron microscopy and immunoblotting data indicated that these analogs induced robust autophagy in human macrophages. This study is the first report to identify brominated noscapines as innate immune pathway anti-inflammatory molecules.

  13. Potent anti-inflammatory activity of novel microtubule-modulating brominated noscapine analogs.

    Directory of Open Access Journals (Sweden)

    Susu Zughaier

    Full Text Available Noscapine, a plant-derived, non-toxic, over-the-counter antitussive alkaloid has tubulin-binding properties. Based upon the structural resemblance of noscapine to colchicine, a tubulin-binding anti-inflammatory drug, noscapine and its semi-synthetic brominated analogs were examined for in vitro anti-inflammatory activity. Brominated noscapine analogs were found to inhibit cytokine and chemokine release from macrophage cell lines but did not affect cell viability. Brominated noscapine analogs demonstrated anti-inflammatory properties in both TLR- and non-TLR induced in vitro innate immune pathway inflammation models, mimicking septic and sterile infection respectively. In addition, electron microscopy and immunoblotting data indicated that these analogs induced robust autophagy in human macrophages. This study is the first report to identify brominated noscapines as innate immune pathway anti-inflammatory molecules.

  14. In vitro screening of the endocrine disrupting potency of brominated flame retardants and their metabolites

    NARCIS (Netherlands)

    Hamers, T.H.M.; Kamstra, J.H.; Sonneveld, E.; Murk, A.J.; Zegers, B.N.; Boon, J.P.; Brouwer, A.

    2004-01-01

    DEVELOPMENTAL AND REPRODUCTIVE TOXICITY vitro screening the endocrine disrupting potency brominated flame retardants and their metabolites Timo Hamers Jorke Kamstra Edwin Sonneveld Albertinka Murk Bart Zegers Jan Boon Abraham Brouwer Institute for Environmental Studies IVM Amsterdam BioDetection Sys

  15. A Novel Protocol for the Regioselective Bromination of Primary Alcohols in Unprotected Carbohydrates or Glycosides

    Institute of Scientific and Technical Information of China (English)

    薛伟华; 张立芬

    2012-01-01

    The regioselective and efficient bromination of primary hydroxyl groups in unprotected carbohydrates or glycosides is successfully achieved by using (chloro-phenylthio-methylene)dimethylammoniumchloride (CPMA) in the presence of tetrabutylammonium bromide (TBAB) in dry DMF.

  16. Dynamic dielectric properties and the γ transition of bromine doped polyacrylonitrile

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available Based on monitoring the γ process (the lowest temperature-relaxation in polyacrylonitrile (PAN by dynamic dielectric spectroscopy, new evidence for the formation of a charge transfer complex between bromine dopants and nitrile groups is presented. The experimental work is carried out on PAN and nitrile polymerized PAN with and without bromine doping and the effects of these factors on the γ process are measured. Nitrile polymerization results in diminishing of the γ process and in a 15% increase in its activation energy, whereas bromine doping produces splitting of the original γ process in PAN – coupled with a significant activation energy increase – and its complete disappearance in nitrile polymerized PAN. Both the splitting of the γ process and the higher activation energy reflect bromine-nitrile adduct formation..

  17. Evaluation of carbon cryogels used as cathodes for non-flowing zinc-bromine storage cells

    Energy Technology Data Exchange (ETDEWEB)

    Ayme-Perrot, David; Walter, Serge; Gabelica, Zelimir [Groupe Securite et Ecologie Chimiques (GSEC), ENSCMu, 3 rue Alfred Werner, F-68093 Mulhouse Cedex (France); Valange, Sabine [Laboratoire de Catalyse en Chimie Organique (LACCO), ESIP, 40 Avenue du Recteur Pineau, F-86022 Poitiers Cedex (France)

    2008-01-03

    Monolithic megaloporous carbon cryogels were examined for their potential applications as cathodic electrodes in secondary zinc-bromine cells. This work investigates the possibility of using their particular macroporous texture as microscopic bromine tanks in a zinc/bromine battery. The electrochemical behaviour of a cell based upon such a Br{sub 2} electrode was studied and discussed in terms of energy yields, energy storage capability and cycle life. Good storages (over 20 Wh kg{sup -1}) could be obtained during the first 2 h of cell charging for currents between 10 and 20 mA g{sup -1}. The energy yield remains almost constant during a fairly large number of cycles, basically for weak charges (e.g. 25 C g{sup -1}). Our findings show that the good cyclability of the cathodic electrode is a consequence of the liquid state of the active bromine phase. (author)

  18. New insight into photo-bromination processes in saline surface waters: The case of salicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tamtam, Fatima; Chiron, Serge, E-mail: serge.chiron@msem.univ-montp2.fr

    2012-10-01

    It was shown, through a combination of field and laboratory observations, that salicylic acid can undergo photo-bromination reactions in sunlit saline surface waters. Laboratory-scale experiments revealed that the photochemical yields of 5-bromosalicylic acid and 3,5-dibromosalicylic acid from salicylic acid were always low (in the 4% range at most). However, this might be of concern since these compounds are potential inhibitors of the 20{alpha}-hydroxysteroid dehydrogenase enzyme, with potential implications in endocrine disruption processes. At least two mechanisms were involved simultaneously to account for the photo-generation of brominated substances. The first one might involve the formation of reactive brominated radical species (Br{center_dot}, Br{sub 2}{center_dot}{sup -}) through hydroxyl radical mediated oxidation of bromide ions. These ions reacted more selectively than hydroxyl radicals with electron-rich organic pollutants such as salicylic acid. The second one might involve the formation of hypobromous acid, through a two electron oxidation of bromine ions by peroxynitrite. This reaction was catalyzed by nitrite, since these ions play a crucial role in the formation of nitric oxide upon photolysis. This nitric oxide further reacts with superoxide radical anions to yield peroxynitrite and by ammonium through the formation of N-bromoamines, probably due to the ability of N-bromoamines to promote the aromatic bromination of phenolic compounds. Field measurements revealed the presence of salicylic acid together with 5-bromosalicylic and 3,5-dibromosalicylic acid in a brackish coastal lagoon, thus confirming the environmental significance of the proposed photochemically induced bromination pathways. -- Highlights: Black-Right-Pointing-Pointer Brominated derivatives of salicylic acid were detected in a brackish lagoon. Black-Right-Pointing-Pointer A photochemical pathway was hypothesized to account for bromination of salicylic acid. Black

  19. Bromine-lithium exchange: An efficient tool in the modular construction of biaryl ligands.

    Science.gov (United States)

    Bonnafoux, Laurence; Leroux, Frédéric R; Colobert, Françoise

    2011-01-01

    Regioselective bromine-lithium exchange reactions on polybrominated biaryls enable the modular synthesis of various polysubstituted biphenyls such as bis(dialkylphosphino)-, bis(diarylphosphino)- and dialkyl(diaryl)phosphinobiphenyls. All permutations of substituents at the ortho positions of the biphenyls are possible. In a similar manner, one can gain access to monophosphine analogues. So far, such a process, based on the effective discrimination between bromine atoms as a function of their chemical environment, has been observed only sporadically.

  20. Gaia Paradigm: A Biotic Origin Of The Polar Sunrise Arctic Bromine Explosion

    OpenAIRE

    Iudin, M.

    2008-01-01

    The main attention is given to discussion of the natural causes and regularities of the Arctic bromine pollution. We make notice of marine microbial organisms and their metabolism as a prime driving force for the elemental biogeochemical cycles. One of the important conclusions of this study is on similarity between ocean bromine concentrating as by-product of the marine microbial activities and nitrogen fixation by soil bacteria. In both cases, microbial organisms and their food webs maintai...

  1. Surface Response of Brominated Carbon Media on Laser and Thermal Excitation: Optical and Thermal Analysis Study

    Science.gov (United States)

    Multian, Volodymyr V.; Kinzerskyi, Fillip E.; Vakaliuk, Anna V.; Grishchenko, Liudmyla M.; Diyuk, Vitaliy E.; Boldyrieva, Olga Yu.; Kozhanov, Vadim O.; Mischanchuk, Oleksandr V.; Lisnyak, Vladyslav V.; Gayvoronsky, Volodymyr Ya.

    2017-02-01

    The present study is objected to develop an analytical remote optical diagnostics of the functionalized carbons surface. Carbon composites with up to 1 mmol g-1 of irreversibly adsorbed bromine were produced by the room temperature plasma treatment of an activated carbon fabric (ACF) derived from polyacrylonitrile textile. The brominated ACF (BrACF) was studied by elastic optical scattering indicatrix analysis at wavelength 532 nm. The obtained data were interpreted within results of the thermogravimetric analysis, X-ray photoelectron spectroscopy and temperature programmed desorption mass spectrometry. The bromination dramatically reduces the microporosity producing practically non-porous material, while the incorporated into the micropores bromine induces the dielectric and structural impact on surface polarizability and conductivity due to the charging effect. We have found that the elastic optical scattering in proper solid angles in the forward and the backward hemispheres is sensitive to the kind of the bromine bonding, e.g., physical adsorption or chemisorption, and the bromination level, respectively, that can be utilized for the express remote fabrication control of the nanoscale carbons with given interfaces.

  2. Photothermally induced bromination of carbon/polymer bipolar plate materials for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Martin; Franzka, Steffen [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Cappuccio, Franco; Peinecke, Volker; Heinzel, Angelika [Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Zentrum für BrennstoffzellenTechnik (ZBT), Carl-Benz-Straße 201, 47057 Duisburg (Germany); Hartmann, Nils, E-mail: nils.hartmann@uni-due.de [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany)

    2015-05-01

    Graphical abstract: - Highlights: • Photothermal laser bromination of carbon/polymer materials is demonstrated. • Using a microfocused laser functionalized domains with diameters of 5 μm and 100 μm and more can be fabricated. • Bromine groups can be transformed in a variety of other chemical functionalities, i.e. amine groups. • Depending on the chemical functionality, the local chemical affinity and wettability is changed. • The routine can be applied to standard bipolar plate materials used for fuel cell applications. - Abstract: A facile photothermal procedure for direct functionalization of carbon/polymer bipolar plate materials is demonstrated. Through irradiation with a microfocused beam of an Ar{sup +}-laser at λ = 514 nm in gaseous bromine and distinct laser powers and pulse lengths local bromination of the carbon/polymer material takes place. At a 1/e spot diameter of 2.1 μm, functionalized surface areas with diameters down to 5 μm are fabricated. In complementary experiments large-area bromination is investigated using an ordinary tungsten lamp. For characterization contact angle goniometry, X-ray photoelectron spectroscopy and electron microscopy in conjunction with labeling techniques are employed. After irradiation bromine groups can easily be substituted by other chemical functionalities, e.g. azide and amine groups. This provides a facile approach in order to fabricate surface patterns and gradient structures with varying wetting characteristics. Mechanistic aspects and prospects of photothermal routines in micropatterning of carbon/polymer materials are discussed.

  3. Sesquiterpenes and an intermediate 1alpha, 6beta, 11-eudesmanetriol in the biosynthesis of geosmin from Streptomyces sp.

    Science.gov (United States)

    Yang, Ya-Bin; Yang, Zhi; Yang, Xue-Qiong; Zhang, Yong; Zhao, Li-Xing; Xu, Li-Hua; Ding, Zhong-Tao

    2012-03-01

    One new sesquiterpene was isolated from the fermentation broth of Streptomyces sp. and the structure was elucidated by spectral analysis as caryolane-1, 6beta-diol (1). An intermediate 1alpha, 6beta, 11-eudesmanetriol (2) in the biosynthesis of geosmin was also found in this strain which proved sequence for the reactions, especially bicyclization preceding dealkylation.

  4. Artemisinin-derived sesquiterpene lactones as potential antitumour compounds : Cytotoxic action against bone marrow and tumour cells

    NARCIS (Netherlands)

    Beekman, AC; Wierenga, PK; Woerdenbag, HJ; Van Uden, W; Pras, N; Konings, AWT; El-Feraly, FS; Galal, AM; Wikstrom, HV

    1998-01-01

    We determined the in vitro cytotoxic activity of the sesquiterpene lactone endoperoxide artemisinin (1) and some chemically prepared derivatives, which have been found to display cytotoxicity to cloned murine Ehrlich ascites tumour (EAT) cells and human HeLa cells and against murine bone marrow usin

  5. CYTOTOXICITY OF FLAVONOIDS AND SESQUITERPENE LACTONES FROM ARNICA SPECIES AGAINST THE GLC(4) AND THE COLO-320 CELL-LINES

    NARCIS (Netherlands)

    WOERDENBAG, HJ; MERFORT, [No Value; PASSREITER, CM; SCHMIDT, TJ; WILLUHN, G; VANUDEN, W; PRAS, N; KAMPINGA, HH; KONINGS, AWT

    1994-01-01

    The cytotoxicity of 21 flavonoids and 5 sesquiterpene lactones, as present in Arnica species, was studied in GLC(4), a human small cell lung carcinoma cell line, and in COLO 320, a human colorectal cancer cell line, using the microculture tetrazolium (MTT) assay. Following continuous incubation, mos

  6. Sesquiterpene emissions from Alternaria alternata and Fusarium oxysporum: Effects of age, nutrient availability, and co-cultivation.

    Science.gov (United States)

    Weikl, Fabian; Ghirardo, Andrea; Schnitzler, Jörg-Peter; Pritsch, Karin

    2016-02-26

    Alternaria alternata is one of the most studied fungi to date because of its impact on human life - from plant pathogenicity to allergenicity. However, its sesquiterpene emissions have not been systematically explored. Alternaria regularly co-occurs with Fusarium fungi, which are common plant pathogens, on withering plants. We analyzed the diversity and determined the absolute quantities of volatile organic compounds (VOCs) in the headspace above mycelial cultures of A. alternata and Fusarium oxysporum under different conditions (nutrient rich and poor, single cultures and co-cultivation) and at different mycelial ages. Using stir bar sorptive extraction and gas chromatography-mass spectrometry, we observed A. alternata to strongly emit sesquiterpenes, particularly during the early growth stages, while emissions from F. oxysporum consistently remained comparatively low. The emission profile characterizing A. alternata comprised over 20 sesquiterpenes with few effects from nutrient quality and age on the overall emission profile. Co-cultivation with F. oxysporum resulted in reduced amounts of VOCs emitted from A. alternata although its profile remained similar. Both fungi showed distinct emission profiles, rendering them suitable biomarkers for growth-detection of their phylotype in ambient air. The study highlights the importance of thorough and quantitative evaluations of fungal emissions of volatile infochemicals such as sesquiterpenes.

  7. XPS STUDIES ON SURFACE MODIFIED POLY[1-(TRIMETHYLSILYL)-1-PROPYNE] MEMBRANES Ⅱ SURFACE MODIFICATION BY BROMINE VAPOR

    Institute of Scientific and Technical Information of China (English)

    XU Guanfan; SUN Xiaoguang; QIU Xuepeng; ZHANG Jinlan; ZHENG Guodong

    1994-01-01

    Surface modification of poly [ 1-(trimethylsilyl )-1-propyne ] ( PTMSP ) membranes by bromine vapor has been studied. It is shown that Br/C atomic ratio at the surfacesincreased with the time of bromination until about 60 min, then it reached a plateau. The results of XPS and IR studies indicated that the addition of bromine to double bonds and the replacement of H on CH3 by bromine had taken place so that a new peak at 286.0 eV (C-Br)in C1sspectra and some new bands, e. g. at 1220 and 580cm-1,in IR spectra were formed. The fact, Po2, permeability of oxygen, decreased and αO2/N2, separation factor of oxygen relative to nitrogen, increased with bromination time, shows that surface modification of PTMSP by bromine may be an efficient approachto prepare PTMSP membranes used for practical gas separations.

  8. INVESTIGATION OF HYPOLIPIDEMIC EFFECT OF SESQUITERPENE Γ-LACTONE AHILLIN IN HEPATOMA TISSUE CULTURE (HTC CELLS

    Directory of Open Access Journals (Sweden)

    V. V. Ivanov

    2014-01-01

    Full Text Available Objective. Investigation of hypolipidemic effect of sesquiterpene γ-lactone ahillin in hepatoma tissue culture (HTC cells.Material and methods. In this study we’ve evaluated the effect of γ-lactone sesquiterpene aсhillin and gemfibrozil (comparator drug on the lipid content in the hepatoma tissue culture (HTC cell which were incubated with a fat emulsion lipofundin by fluorescent method with vital dye Nile Redand staining the cells with the dye Oil Red O. The cell viability was investigated using the MTT-test and staining with Trypan blue.Results. Cultivation cells HTC with aсhillin and gemfibrozilat concentrations ranging from 0.5 to1.5 mM and from0.25 mM to0.5 mM, respectively, resulted in dose-dependent decrease of the fluorescence’s intensity Nile Red. It reflects a decrease in lipid content in the cells. At these concentrations the drugs didn’t have cytotoxic effect and the cell viability didn’t change compared to the control culture.An experimental hyperlipidemia in the hepatoma culture cells was induced by adding to the incubation medium a fat emulsion lipofundin at a final concentration 0.05%. The intensity of fluorescence Nile Red in the cells was increased 4 fold (p < 0.05. This result suggests the significant accumulation of lipids in the cell’s cytosol and confirmed by microscopy after staining neutral lipids with the dye Oil Red O. Under these conditions aсhillin and gemfibrozil reduced lipid content in cells and hadthe effect at concentrations of0.5 mM and0.25 mM respectively.Conclusion. In the lipofundin-mediated model of hyperlipidemia the sesquiterpene lactone aсhillin prevents the lipid accumulation in cells. It confirms by decrease of fluorescence Nile Red and reduction lipid drops which were stained with Oil Red O in cytosol. To establish the molecular targets of aсhillin’saction on lipid metabolism in cell culture HTC we need to investigate a gene expression of key enzymes of lipid metabolism.

  9. Preisocalamendiol, Shyobunol and Related Oxygenated Sesquiterpenes from Bolivian Schinus molle Essential Oil.

    Science.gov (United States)

    St-Gelais, Alexis; Mathieu, Michel; Levasseur, Virginie; Ovando, Jesús Flores; Escamilla, Ruben; Marceau, Hubert

    2016-04-01

    Five batches of Bolivian Schinus molle essential oils were obtained from pilot and industrial-scale hydrodiffusions. They were analyzed by gas chromatography to find 80 known compounds and two unknown molecules. In particular, preisocalamendiol (5.6-11.0 %) was found to be an important constituent of these oils, along with shyobunol (0.6-3.2 %) and several other related oxygenated sesquiterpenes. These compounds, usually found in Acorus calamus, had not been reported altogether in S. molle essential oils previously. These findings, in light of the GABAA positive modulating effect of shyobunone and preisocalamendiol, along with some traditional uses of S. molle, suggest that further investigation of the tranquilizing properties of these Bolivian oils would be of interest.

  10. Diversion of flux toward sesquiterpene production in Saccharomyces cerevisiae by fusion of host and heterologous enzymes

    DEFF Research Database (Denmark)

    Albertsen, Line; Chen, Yun; Bach, Lars Stougaard

    2011-01-01

    The ability to transfer metabolic pathways from the natural producer organisms to the well-characterized cell factory Saccharomyces cerevisiae is well documented. However, as many secondary metabolites are produced by collaborating enzymes assembled in complexes, metabolite production in yeast ma...... demonstrates that engineering the spatial organization of metabolic enzymes around a branch point has great potential for diverting flux toward a desired product. ©American Society for Microbiology. All rights reserved.......The ability to transfer metabolic pathways from the natural producer organisms to the well-characterized cell factory Saccharomyces cerevisiae is well documented. However, as many secondary metabolites are produced by collaborating enzymes assembled in complexes, metabolite production in yeast may...... increased the production of patchoulol, the main sesquiterpene produced by PTS, up to 2-fold. Moreover, we have demonstrated that the fusion strategy can be used in combination with traditional metabolic engineering to further increase the production of patchoulol. This simple test case of synthetic biology...

  11. Antiphytoviral Activity of Sesquiterpene-Rich Essential Oils from Four Croatian Teucrium Species

    Directory of Open Access Journals (Sweden)

    Franko Burčul

    2011-09-01

    Full Text Available The purpose of this study was to compare the essential oil profiles of four Croatian Teucrium species (Lamiaceae, as determined by GC and GC/MS, with their antiphytoviral efficiency. A phytochemical analysis showed that T. polium, T. flavum, T. montanum and T. chamaedrys are characterized by similar essential oil compositions. The investigated oils are characterized by a high proportion of the sesquiterpene hydrocarbons β-caryophyllene (7.1–52.0% and germacrene D (8.7–17.0%. Other important components were β-pinene from T. montanum and α-pinene from T. flavum. The investigated essential oils were proved to reduce lesion number in the local host Chenopodium quinoa Willd. infected with Cucumber Mosaic Virus (CMV, with reductions of 41.4%, 22.9%, 44.3% and 25.7%, respectively.

  12. Covalent modification of human serum albumin by the natural sesquiterpene lactone parthenolide.

    Science.gov (United States)

    Plöger, Michael; Sendker, Jandirk; Langer, Klaus; Schmidt, Thomas J

    2015-04-09

    The reactivity of parthenolide (PRT), a natural sesquiterpene lactone from Tanacetum parthenium (Asteraceae), with human serum albumin (HSA) was studied by UHPLC/+ESI-QqTOF MS analysis after tryptic digestion of albumin samples after incubation with this compound. It was found that the single free cysteine residue, C34, of HSA (0.6 mM) reacted readily with PRT when incubated at approximately 13-fold excess of PRT (8 mM). Time-course studies with PRT and its 11β,13-dihydro derivative at equimolar ratios of the reactants revealed that PRT under the chosen conditions reacts preferably with C34 and does so exclusively via its α-methylene-γ-lactone moiety, while the epoxide structure is not involved in the reaction.

  13. Total assignment of 1H and 13C NMR data for the sesquiterpene lactone 15-deoxygoyazensolide.

    Science.gov (United States)

    Heleno, Vladimir Constantino Gomes; Crotti, Antônio Eduardo Miller; Constantino, Mauricio Gomes; Lopes, Norberto Peporine; Lopes, João Luis Callegari

    2004-03-01

    We describe a complete analysis of the 1H and 13C spectra of the anti-inflamatory, schistossomicidal and trypanosomicidal sesquiterpene lactone 15-deoxygoyazensolide. This lactone, with a structure similar to other important ones, was studied by NMR techniques such as COSY, HMQC, HMBC, Jres and NOE experiments. The comparison of the data with some computational results led to an unequivocal assignment of all hydrogen and carbon chemical shifts, even eliminating some previous ambiguities. We were able to determine all hydrogen coupling constants (J) and signal multiplicities and to confirm the stereochemistry. A new method for the determination of the relative position of the lactonization and the position of the ester group on a medium-sized ring by NMR was developed.

  14. Enhancing sesquiterpene production in Saccharomyces cerevisiae through in silico driven metabolic engineering

    DEFF Research Database (Denmark)

    Asadollahi, Mohammadali; Maury, Jerome; Patil, Kiran Raosaheb;

    2009-01-01

    and minimization of metabolic adjustments (MOMA) as objective function. Deletion of NADPH-dependent glutamate dehydrogenase encoded by GDH1 was identified as the best target gene for the improvement of sesquiterpene biosynthesis in yeast. Deletion of this gene enhances the available NADPH in the cytosol for other...... NADPH requiring enzymes, including HMG-CoA reductase. However, since disruption of GDH1 impairs the ammonia utilization, simultaneous over-expression of the NADH-dependent glutamate dehydrogenase encoded by GDH2 was also considered in this study. Deletion of GDH1 led to an approximately 85% increase...... in the final cubebol titer. However, deletion of this gene also caused a significant decrease in the maximum specific growth rate. Over-expression of GDH2 did not show a further effect on the final cubebol titer but this alteration significantly improved the growth rate compared to the GDH1 deleted strain....

  15. Beyerane derivatives and a sesquiterpene dimer from Japanese Cypress (Chamaecyparis obtusa).

    Science.gov (United States)

    Gao, Hui Yuan; Wu, Li Jun; Muto, Norio; Fuchino, Hiroyuki; Nakane, Takahisa; Shirota, Osamu; Sano, Toshikazu; Kuroyanagi, Masanori

    2008-07-01

    In the course of studies on biological active constituents from woody plants, we previously reported the isolation of many lignan derivatives as neurite outgrowth-promoting compounds from an ethyl acetate soluble fraction of Japanese Cypress (Chamaecyparis obtusa). Further chemical investigation on the residual parts of the ethyl acetate soluble fraction of a methanol extract of Japanese Cypress resulted in the isolation of four new beyerene type derivatives and a novel sesquiterpene dimer formed between cryptomeridiol and hinokiic acid. Their structures were elucidated as 18-O-(Z)-p-coumaroylbeyer-15-ene-18-ol (1), 18-O-(E)-p-coumaroylbeyer-15-ene-18-ol (2), 18-O-(E)-p-coumaroylbeyer-15-ene-11beta,18-diol (3), 18-O-(Z)-p-coumaroylbeyer-15-ene-11beta,18-diol (4) and ent-cryptomeridiol-4-yl-hinokiiate (5) by (1)H-NMR, (13)C-NMR, 2D-NMR, and HR-MS spectral analysis.

  16. Sesquiterpene lactone content in leaves of in vitro and field cultivated Arnica montana.

    Science.gov (United States)

    Schmidt, T J; Bomme, U; Alfermann, A W

    1998-04-01

    On the basis of GC and GC/MS analyses we report on the full qualitative and quantitative sesquiterpene lactone (STL) content of in vitro cultivated A. montana plantlets consisting of helenalin and 11alpha,13-dihydrohelenalin esters in approximately equal amounts. The accumulation of STL was shown to be correlated with tissue differentiation in the above-ground parts. The seasonal variation of STL content in leaves of A. montana cultivated in the proving field was investigated. Changes in the composition of the STL fraction were detected. While young plants accumulate mainly helenalin derivatives, the content of such compounds decreases to almost zero within about 6 weeks from the beginning of leaf formation while that of dihydrohelenalin type compounds increases at the same rate and remains constant for a longer period.

  17. Covalent Modification of Human Serum Albumin by the Natural Sesquiterpene Lactone Parthenolide

    Directory of Open Access Journals (Sweden)

    Michael Plöger

    2015-04-01

    Full Text Available The reactivity of parthenolide (PRT, a natural sesquiterpene lactone from Tanacetum parthenium (Asteraceae, with human serum albumin (HSA was studied by UHPLC/+ESI-QqTOF MS analysis after tryptic digestion of albumin samples after incubation with this compound. It was found that the single free cysteine residue, C34, of HSA (0.6 mM reacted readily with PRT when incubated at approximately 13-fold excess of PRT (8 mM. Time-course studies with PRT and its 11β,13-dihydro derivative at equimolar ratios of the reactants revealed that PRT under the chosen conditions reacts preferably with C34 and does so exclusively via its α-methylene-γ-lactone moiety, while the epoxide structure is not involved in the reaction.

  18. Chamigrane Sesquiterpenes from a Basidiomycetous Endophytic Fungus XG8D Associated with Thai Mangrove Xylocarpus granatum

    Science.gov (United States)

    Choodej, Siwattra; Teerawatananond, Thapong; Mitsunaga, Tohru; Pudhom, Khanitha

    2016-01-01

    Six new chamigrane sesquiterpenes, merulinols A‒F (1‒6), and four known metabolites (7‒10) were isolated from the culture of the basidiomycetous fungus XG8D, a mangrove-derived endophyte. Their structures were elucidated mainly by 1D and 2D NMR, while the structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction analysis. The in vitro cytotoxicity of all compounds was evaluated against three human cancer cell lines, MCF-7, Hep-G2, and KATO-3. Compounds 3 and 4 selectively displayed cytotoxicity against KATO-3 cells with IC50 values of 35.0 and 25.3 μM, respectively. PMID:27428984

  19. Chamigrane Sesquiterpenes from a Basidiomycetous Endophytic Fungus XG8D Associated with Thai Mangrove Xylocarpus granatum

    Directory of Open Access Journals (Sweden)

    Siwattra Choodej

    2016-07-01

    Full Text Available Six new chamigrane sesquiterpenes, merulinols A‒F (1‒6, and four known metabolites (7‒10 were isolated from the culture of the basidiomycetous fungus XG8D, a mangrove-derived endophyte. Their structures were elucidated mainly by 1D and 2D NMR, while the structures of 1 and 2 were further confirmed by single-crystal X-ray diffraction analysis. The in vitro cytotoxicity of all compounds was evaluated against three human cancer cell lines, MCF-7, Hep-G2, and KATO-3. Compounds 3 and 4 selectively displayed cytotoxicity against KATO-3 cells with IC50 values of 35.0 and 25.3 μM, respectively.

  20. Bromine partitioning between olivine and melt at OIB source conditions: Indication for volatile recycling

    Science.gov (United States)

    Joachim, Bastian; Ruzié, Lorraine; Burgess, Ray; Pawley, Alison; Clay, Patricia L.; Ballentine, Christopher J.

    2016-04-01

    Halogens play a key role in our understanding of volatile transport processes in the Earth's mantle. Their moderate (fluorine) to highly (iodine) incompatible and volatile behavior implies that their distribution is influenced by partial melting, fractionation and degassing processes as well as fluid mobilities. The heavy halogens, particularly bromine and iodine, are far more depleted in the Earth's mantle than expected from their condensation temperature (Palme and O'Neill 2014), so that their very low abundances in basalts and peridotites (ppb-range) make it analytically challenging to investigate their concentrations in Earth's mantle reservoirs and their behavior during transport processes (Pyle and Mather, 2009). We used a new experimental technique, which combines the irradiation technique (Johnson et al. 2000), laser ablation and conventional mass spectrometry. This enables us to present the first experimentally derived bromine partition coefficient between olivine and melt. Partitioning experiments were performed at 1500° C and 2.3 GPa, a P-T condition that is representative for partial melting processes in the OIB source region (Davis et al. 2011). The bromine partition coefficient between olivine and silicate melt at this condition has been determined to DBrol/melt = 4.37•10-4± 1.96•10-4. Results show that bromine is significantly more incompatible than chlorine (˜1.5 orders of magnitude) and fluorine (˜2 orders of magnitude) due to its larger ionic radius. We have used our bromine partitioning data to estimate minimum bromine abundances in EM1 and EM2 source regions. We used minimum bromine bulk rock concentrations determined in an EM1 (Pitcairn: 1066 ppb) and EM2 (Society: 2063 ppb) basalt (Kendrick et al. 2012), together with an estimated minimum melt fraction of 0.01 in OIB source regions (Dasgupta et al. 2007). The almost perfect bromine incompatibility results in minimum bromine abundances in EM1 and EM2 OIB source regions of 11 ppb and 20

  1. Sesquiterpene Lactones from Gynoxys verrucosa and their Anti-MRSA Activity

    Science.gov (United States)

    Ordóñez, Paola E.; Quave, Cassandra L.; Reynolds, William F.; Varughese, Kottayil I.; Berry, Brian; Breen, Philip J.; Malagón, Omar; Smeltzer, Mark S.; Compadre, Cesar M.

    2011-01-01

    Ethnopharmacological relevance Because of its virulence and antibiotic resistance, Staphylococcus aureus is a more formidable pathogen now than at any time since the pre-antibiotic era. In an effort to identify and develop novel antimicrobial agents with activity against this pathogen, we have examined Gynoxys verrucosa Wedd (Asteraceae), an herb used in traditional medicine in southern Ecuador for the treatment and healing of wounds. Materials and Methods The sesquiterpene lactones leucodine (1) and dehydroleucodine (2) were extracted and purified from the aerial parts of G. verrucosa, and their structure was elucidated by spectroscopic methods and single-crystal X-ray analysis. The in vitro anti-microbial activity of G. verrucosa extracts and its purified constituents was determined against six clinical isolates including S. aureus and Staphylococcus epidermidis strains with different drug-resistance profiles, using the microtiter broth method. Results Compound 1 has very low activity, while compound 2 has moderate activity with MIC50s between 49 and195 μg/mL. The extract of G. verrucosa has weak activity with MIC50s between 908 and 3290 μg/mL. Conclusions We are reporting the full assignment of the 1H-NMR and 13C-NMR of both compounds, and the crystal structure of compound 2, for the first time. Moreover, the fact that compound 2 has antimicrobial activity and compound 1 does not, demonstrates that the exocyclic conjugated methylene in the lactone ring is essential for the antimicrobial activity of these sesquiterpene lactones. However, the weak activity observed for the plants extracts, does not explain the use of G. verrucosa in traditional medicine for the treatment of wounds and skin infections. PMID:21782013

  2. Evaluation of mosquitocidal activity of essential oil and sesquiterpenes from leaves of Chloroxylon swietenia DC.

    Science.gov (United States)

    Kiran, S Ravi; Devi, P Sita

    2007-07-01

    Growing awareness in using ecofriendly and biologically compatible phytoconstituents as natural insecticides and repellents for the safety of life and ecological balance led to conscientious efforts by scientists all over the world to search for alternative sources of plant derivatives for effective use as mosquitocides. Encouraged by this, the essential oil and the sesquiterpenes isolated from the leaves of Chloroxylon swietenia DC. were screened for mosquitocidal activity by fumigant toxicity against three mosquito species, Anopheles gambiae, Culex quinquefasciatus and Aedes aegypti. The essential oil had pronounced mosquitocidal activity with LD50 of 1.0, 1.2 and 1.7 x 10(-3) mg/cm(-3), respectively, for the three vector species. Furthermore, the major sesquiterpenes were tested at different doses, which again showed varying levels of toxicity. However, germacrene D performed better and proved to be the potential candidate with LD50 values of 1.8-2.8 x 10(-3) mg/cm(-3) followed by pregeijerene and geijerene. Nevertheless, the oil and the isolated compounds were particularly active against A. gambiae. The essential oil from the leaves was obtained by hydrodistillation, and the chemical composition was determined by GC and GC-MS. The main compounds identified were limonene, germacrene D, geijerene, pregeijerene, trans-beta-ocimene and methyl eugenol. The present study indicates that the oil and the isolated compounds of C. swietenia displayed remarkable mosquitocidal activity suggesting that the method could be extended for future field trials in various mosquito control programmes, and the results are compared with synthetic insecticides.

  3. Revisiting sesquiterpene biosynthetic pathways leading to santalene and its analogues: a comprehensive mechanistic study.

    Science.gov (United States)

    Jindal, Garima; Sunoj, Raghavan B

    2012-10-21

    Santalene and bergamotene are the major olefinic sesquiterpenes responsible for the fragrance of sandalwood oil. Herein we report the details of density functional theory investigations on the biosynthetic pathway of this important class of terpenes. The mechanistic study has been found to be effective toward gaining significant new insight into different possibilities for the formation of the key intermediates involved in santalene and bergamotene biosynthesis. The stereoelectronic features of the transition states and intermediates for (i) ring closure of the initial bisabolyl cation, and (ii) skeletal rearrangements in the ensuing bicyclic carbocationic intermediates leading to (-)-epi-β-santalene, (-)-β-santalene, (-)-α-santalene, (+)-epi-β-santalene, exo-β-bergamotene, endo-β-bergamotene, exo-α-bergamotene, and endo-α-bergamotene are presented. Interesting structural features pertaining to certain new carbocationic intermediates (such as b) resulting from the ring closure of bisabolyl cation are discussed. Extensive conformational sampling of all key intermediates along the biosynthetic pathway offered new insight into the role of the isoprenyl side chain conformation in the formation of santalene and its analogues. Although the major bicyclic products in Santalum album appear to arise from the right or left handed helical form of farnesyl pyrophosphate (FPP), different alternatives for their formation are found to be energetically feasible. The interconversion of the exo and endo isomers of bisabolyl cation and a likely epimerization, both with interesting mechanistic implications, are presented. The exo to endo conversion is identified to be energetically more favorable than another pathway emanating from the left handed helical FPP. The role of pyrophosphate (OPP(-)) in the penultimate deprotonation step leading to olefinic sesquiterpenes is also examined.

  4. Anti-inflammatory sesquiterpene lactones from Lychnophora trichocarpha Spreng. (Brazilian Arnica).

    Science.gov (United States)

    Ferrari, Fernanda C; Ferreira, Leidiane C; Souza, Maíra R; Grabe-Guimarães, Andrea; Paula, Carmen A; Rezende, Simone A; Saúde-Guimarães, Dênia A

    2013-03-01

    The aerial parts of Lychnophora trichocarpha Spreng. (Asteraceae) are used macerated in water or ethanol to treat inflammation, pain, rheumatism, contusions, bruises and insect bites in Brazilian traditional medicine. In this study, anti-inflammatory activity of ethanol extract from aerial parts of L. trichocarpha and its ethyl acetate fraction was investigated. Sesquiterpene lactones, lychnopholide (Lyc) and eremantholide C (EreC), isolated of ethyl acetate fraction, were also assayed for in vitro and in vivo anti-inflammatory activity. Topical treatment with ointments containing ethanol extract, its ethyl acetate fraction and sesquiterpene lactones significantly reduced carrageenan-induced mice paw oedema. In vitro assays demonstrated that Lyc inhibited interferon -γ/lipopolysaccharide -stimulated nitric oxide (NO) production in J774A.1 macrophages and increased production of IL-10 anti-inflammatory cytokine. The reduction of tumor necrosis factor-α (TNF-α) production by EreC was accompanied by an increased production of IL-10 in a concentration-dependent manner in J774A.1 macrophages. The anti-inflammatory effect of Lyc seems to involve the inhibition of production of NO and increased production of IL-10. The mechanism of the effect of EreC on the reduction of carrageenan-induced paw oedema may be attributed to inhibition of production of TNF-α and stimulation of IL-10 production. The results corroborate the use of ethanol extract from Lychnophora trichocarpha in folk medicine for anti-inflammatory action and indicate that the topical route is suitable for use.

  5. Automating gene library synthesis by structure-based combinatorial protein engineering: examples from plant sesquiterpene synthases.

    Science.gov (United States)

    Dokarry, Melissa; Laurendon, Caroline; O'Maille, Paul E

    2012-01-01

    Structure-based combinatorial protein engineering (SCOPE) is a homology-independent recombination method to create multiple crossover gene libraries by assembling defined combinations of structural elements ranging from single mutations to domains of protein structure. SCOPE was originally inspired by DNA shuffling, which mimics recombination during meiosis, where mutations from parental genes are "shuffled" to create novel combinations in the resulting progeny. DNA shuffling utilizes sequence identity between parental genes to mediate template-switching events (the annealing and extension of one parental gene fragment on another) in PCR reassembly reactions to generate crossovers and hence recombination between parental genes. In light of the conservation of protein structure and degeneracy of sequence, SCOPE was developed to enable the "shuffling" of distantly related genes with no requirement for sequence identity. The central principle involves the use of oligonucleotides to encode for crossover regions to choreograph template-switching events during PCR assembly of gene fragments to create chimeric genes. This approach was initially developed to create libraries of hybrid DNA polymerases from distantly related parents, and later developed to create a combinatorial mutant library of sesquiterpene synthases to explore the catalytic landscapes underlying the functional divergence of related enzymes. This chapter presents a simplified protocol of SCOPE that can be integrated with different mutagenesis techniques and is suitable for automation by liquid-handling robots. Two examples are presented to illustrate the application of SCOPE to create gene libraries using plant sesquiterpene synthases as the model system. In the first example, we outline how to create an active-site library as a series of complex mixtures of diverse mutants. In the second example, we outline how to create a focused library as an array of individual clones to distil minimal combinations of

  6. An exemplary case of a bromine explosion event linked to cyclone development in the Arctic

    Science.gov (United States)

    Blechschmidt, A.-M.; Richter, A.; Burrows, J. P.; Kaleschke, L.; Strong, K.; Theys, N.; Weber, M.; Zhao, X.; Zien, A.

    2016-02-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by GOME-2 on board the MetOp-A satellite over Arctic sea ice in polar spring. These plumes are often transported by high-latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. However, only few studies have focused on the role of polar weather systems in the development, duration and transport of tropospheric BrO plumes during bromine explosion events. The latter are caused by an autocatalytic chemical chain reaction associated with tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. In this manuscript, a case study investigating a comma-shaped BrO plume which developed over the Beaufort Sea and was observed by GOME-2 for several days is presented. By making combined use of satellite data and numerical models, it is shown that the occurrence of the plume was closely linked to frontal lifting in a polar cyclone and that it most likely resided in the lowest 3 km of the troposphere. In contrast to previous case studies, we demonstrate that the dry conveyor belt, a potentially bromine-rich stratospheric air stream which can complicate interpretation of satellite retrieved tropospheric BrO, is spatially separated from the observed BrO plume. It is concluded that weather conditions associated with the polar cyclone favoured the bromine activation cycle and blowing snow production, which may have acted as a bromine source during the bromine explosion event.

  7. Antimicrobial N-brominated hydantoin and uracil grafted polystyrene beads.

    Science.gov (United States)

    Farah, Shady; Aviv, Oren; Laout, Natalia; Ratner, Stanislav; Domb, Abraham J

    2015-10-28

    Hydantoin-N-halamine derivatives conjugated on polystyrene beads are promising disinfectants with broad antimicrobial activity affected by the gradual release of oxidizing halogen in water. The objective of this work was to identify and test of hydantoin-like molecules possessing urea moiety, which may provide N-haloamines releasing oxidizing halogens when exposed to water at different rates and release profiles for tailored antimicrobial agents. In this work, several hydantoin (five member ring) and for the first time reported, uracil (six member ring) derivatives have been conjugated to polystyrene beads and tested for their lasting antimicrobial activity. Four molecules of each series were conjugated onto polystyrene beads from the reaction of the N-potassium hydantoin or uracil derivatives onto chloromethylated polystyrene beads. A distinct difference in bromine loading capacity and release profiles was found for the different conjugated derivatives. All tested materials exhibit strong antimicrobial activity against Escherichia coli and bacteriophages MS2 of 7 and ~4 log reduction, respectively. These results highlight the antimicrobial potential of halogenated cyclic molecules containing urea groups as water disinfection agents.

  8. Modelling chemistry over the Dead Sea: bromine and ozone chemistry

    Directory of Open Access Journals (Sweden)

    R. von Glasow

    2009-07-01

    Full Text Available Measurements of O3 and BrO concentrations over the Dead Sea indicate that Ozone Depletion Events (ODEs, widely known to happen in polar regions, are also occuring over the Dead Sea due to the very high bromine content of the Dead Sea water. However, we show that BrO and O3 levels as they are detected cannot solely be explained by high Br levels in the Dead Sea water and the release of gas phase halogen species out of sea borne aerosol particles and their conversion to reactive halogen species. It is likely that other sources for reactive halogen compounds are needed to explain the observed concentrations for BrO and O3. To explain the chemical mechanism taking place over the Dead Sea leading to BrO levels of several pmol/mol we used the one-dimensional model MISTRA which calculates microphysics, meteorology, gas and aerosol phase chemistry. We performed pseudo Lagrangian studies by letting the model column first move over the desert which surrounds the Dead Sea region and then let it move over the Dead Sea itself. To include an additional source for gas phase halogen compounds, gas exchange between the Dead Sea water and the atmosphere is treated explicitly. Model calculations indicate that this process has to be included to explain the measurements.

  9. Brominated flame retardants in Belgian little owl (Athene noctua) eggs

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, V.; Covaci, A.; Maervoet, J.; Dauwe, T.; Schepens, P.; Eens, M. [Antwerp Univ. (Belgium)

    2004-09-15

    Since the 1960s, polybrominated diphenylethers (PBDEs), a class of brominated flame retardants (BFRs), are widely used in textiles, plastics, electronic equipment and other materials. Their massive use has led to the ubiquitous presence of PBDEs in the environment and in biota in which the PBDE levels seem to increase rapidly. High concentrations of some congeners may cause adverse effects in both wildlife and in human populations1 and this has led to the growing concern of scientists over the last decade and to the need for more data on environmental levels of PBDEs. The little owl (Athene noctua) is a small sedentary predator, which makes it a very suitable biomonitoring species. This owl species feeds on a variety of preys, including small mammals and birds, reptiles, amphibians, earthworms and beetles, depending on the season and the local circumstances. Because very limited information is available about contamination levels in the little owl, a study was conducted to determine the concentrations of PBDEs, polybrominated biphenyls (PBBs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in deserted or addled eggs of little owls in Belgium. Eggs have been used successfully as a monitoring tool for persistent organic pollutants (POPs) in several studies. Although the analysis of POPs in deserted or addled eggs has clear limitations, these can be partially avoided by analysing only highly persistent components, for which the original composition will not change due to 'posthatching' microbiological degradation.

  10. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    Directory of Open Access Journals (Sweden)

    E. Tas

    2006-01-01

    Full Text Available The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the basic chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the high BrO levels measured frequently at the Dead Sea could only partially be attributed to the highly concentrated Br− present in the Dead Sea water. Furthermore, the RBS activity at the Dead Sea cannot solely be explained by a pure gas phase mechanism. This paper presents a chemical mechanism which can account for the observed chemical activity at the Dead Sea, with the addition of only two heterogeneous processes: the "Bromine Explosion" mechanism and the heterogeneous decomposition of BrONO2. Ozone frequently dropped below a threshold value of ~1 to 2 ppbv at the Dead Sea evaporation ponds, and in such cases, O3 became a limiting factor for the production of BrOx (BrO+Br. The entrainment of O3 fluxes into the evaporation ponds was found to be essential for the continuation of RBS activity, and to be the main reason for the jagged diurnal pattern of BrO observed in the Dead Sea area, and for the positive correlation observed between BrO and O3 at low O3 concentrations. The present study has shown that the heterogeneous decomposition of BrONO2 has a great potential to affect the RBS activity in areas influenced by anthropogenic emissions, mainly due to the positive correlation between the rate of this process and the levels of NO2. Further investigation of the influence of the decomposition of BrONO2 may be especially important in understanding the RBS activity at mid-latitudes.

  11. Measurement-based modeling of bromine chemistry in the boundary layer: 1. Bromine chemistry at the Dead Sea

    Directory of Open Access Journals (Sweden)

    A. Pour Biazar

    2006-06-01

    Full Text Available The Dead Sea is an excellent natural laboratory for the investigation of Reactive Bromine Species (RBS chemistry, due to the high RBS levels observed in this area, combined with anthropogenic air pollutants up to several ppb. The present study investigated the chemical mechanism of RBS at the Dead Sea using a numerical one-dimensional chemical model. Simulations were based on data obtained from comprehensive measurements performed at sites along the Dead Sea. The simulations showed that the high BrO levels measured frequently at the Dead Sea could only partially be attributed to the highly concentrated Br− present in the Dead Sea water. Further, the RBS activity at the Dead Sea cannot solely be explained by a pure gas phase mechanism. This paper presents a chemical mechanism which can account for the observed chemical activity at the Dead Sea, with the addition of only two heterogeneous processes: the "Bromine Explosion" mechanism and the heterogeneous decomposition of BrONO2. Ozone frequently dropped below a threshold value of ~1 to 2 ppbv at the Dead Sea evaporation ponds, and in such cases, O3 became a limiting factor for the production of BrOx (BrO+Br. The entrainment of O3 fluxes into the evaporation ponds was found to be essential for the continuation of RBS activity, and to be the main reason for the positive correlation observed between BrO and O3 at low O3 concentrations, and for the jagged diurnal pattern of BrO observed in the Dead Sea area. The present study has shown that the heterogeneous decomposition of BrONO2 has the potential to greatly affect the RBS activity in areas under anthropogenic influence, mainly due to the positive correlation between the rate of this process and the levels of NO2. Further investigation of the influence of the decomposition of BrONO2 may be especially important in understanding the RBS activity at mid-latitudes.

  12. High-pressure behavior of bromine confined in the one-dimensional channels of zeolite AlPO4-5 single crystals

    Science.gov (United States)

    Liu, Zhaodong; Yao, Zhen; Yao, Mingguang; Lv, Jiayin; Chen, Shuanglong; Li, Quanjun; Lv, Hang; Wang, Tianyi; Lu, Shuangchen; Liu, Ran; Liu, Bo; Liu, Jing; Chen, Zhiqiang; Zou, Bo; Cui, Tian; Liu, Bingbing

    2016-09-01

    We present a joint experimental and theoretical study on the high-pressure behavior of bromine confined in the one-dimensional (1D) nanochannels of zeolite AlPO4-5 (AFI) single crystals. Raman scattering experiments indicate that loading bromine into AFI single crystals can lead to the formation of bromine molecular chains inside the nanochannels of the crystals. High-pressure Raman and X-ray diffraction studies demonstrate that high pressure can increase the length of the confined bromine molecular chains and modify the inter- and intramolecular interactions of the molecules. The confined bromine shows a considerably different high-pressure behavior to that of bulk bromine. The pressure-elongated bromine molecular chains can be preserved when the pressure is reduced to ambient pressure. Theoretical simulations explain the experimental results obtained from the Raman spectroscopy and X-ray diffraction studies. Furthermore, we find that the intermolecular distance between confined bromine molecules gradually becomes comparable to the intramolecular bond length in bromine molecules upon compression. This may result in the dissociation of the bromine molecules and the formation of 1D bromine atomic chains at pressures above 24 GPa. Our study suggests that the unique nanoconfinement has a considerable effect on the high-pressure behavior of bromine, and the confined bromine species concomitantly enhance the structural stability of the host AFI single crystals.

  13. Brominated flame retardants in end-of-life management not problematic regarding formation of brominated dioxins/furans (PBDD/F)

    Energy Technology Data Exchange (ETDEWEB)

    Drohmann, D. [Great Lakes Chemical, Bergisch Gladbach (Germany); Tange, L. [Eurobrom B.V., Rijswijk (Netherlands); Rothenbacher, K. [Bromine Science and Environmental Forum, Brussels (Belgium)

    2004-09-15

    Bromine is used as the building block for some of the most effective flame retarding agents available to the plastics industry today. They are used to protect against the risk of accidental fires in a wide range of products. Brominated flame retardants (BFRs), as all flame retardants, act to decrease the risk of fire by increasing the fire resistance of the materials in which they are applied. There is a perception that BFRs affect adversely the end-of-life management of plastics through formation of brominated dioxins and furans (PBDD/F). In fact, there exists a wide range of data and practical experience demonstrating that the end-of-life management of plastics containing BFRs are fully compliant with legislation setting the strictest limit values for PBDD/F and is fully compatible with an integrated waste management concept. Furthermore, all existing EU Risk Assessments on BFRs according to the European Existing Substance Regulations include an assessment of the potential formation of dioxins and furans. All assessments conclude that the risks along the life-cycle of the chemicals for human health and the environment associated with the potential formation of PBDD/F are negligible. Moreover, two recent Swedish studies found, that consumer products with BFRs emit less pollutants than the same products without any FRs. This paper summarises available studies and presents the latest results regarding potential formation of brominated dioxins and furans in end-of-life management of plastics containing brominated flame retardants. Additionally, before BFR products enter the market they are tested for PBDD/F according to the ''German Dioxin Ordinance''. Depending on the substitution pattern the limit values for PBDD/F are set at <1{mu}g/kg (ppb) respectively <5{mu}g/kg (ppb).

  14. Potent immunosuppressive principles, dimeric sesquiterpene thioalkaloids, isolated from nupharis rhizoma, the rhizoma of Nuphar pumilum (nymphaeaceae): structure-requirement of nuphar-alkaloid for immunosuppressive activity.

    Science.gov (United States)

    Yamahara, J; Shimoda, H; Matsuda, H; Yoshikawa, M

    1996-09-01

    Potent immunosuppressants, the dimeric sesquiterpene thioalkaloids, 6-hydroxythiobinupharidine (2), 6,6'-dihydroxythiobinupharidine (3), 6-hydroxythionuphlutine B (5) and 6'-hydroxythionuphlutine B (6), were isolated from a natural medicine, Nupharis Rhizoma, the rhizoma of Nuphar pumilum (TIMM.) DC., through bioassay-guided separation together with five quinolizidine alkaloids (8, 9, 10, 11, 12). Dimeric sesquiterpene thioalkaloids (2, 3, 5, 6) were found to significantly inhibit anti-sheep erythrocyte plaque forming cell formation in mice spleen cells at 10(-6) M concentration. At this concentration, 2, 5 and 6 were found to exhibit no cytotoxicity to mice spleen cells, and 3 also showed only a little cytotoxicity. In addition, the inhibitory activity of several Nuphar alkaloids, dimeric sesquiterpene thioalkaloids (1, 4, 7, 8), and monomeric sesquiterpene alkaloids (9, 10, 11, 12) on anti-sheep erythrocyte plaque forming cell formation was examined and some structural requirement of Nuphar alkaloid for immunosuppressive activity was determined.

  15. Broad tuning of the human bitter taste receptor hTAS2R46 to various sesquiterpene lactones, clerodane and labdane diterpenoids, strychnine, and denatonium.

    Science.gov (United States)

    Brockhoff, Anne; Behrens, Maik; Massarotti, Alberto; Appendino, Giovanni; Meyerhof, Wolfgang

    2007-07-25

    Sesquiterpene lactones are a major class of natural bitter compounds occurring in vegetables and culinary herbs as well as in aromatic and medicinal plants, where they often represent the main gustatory and pharmacologically active component. Investigations on sesquiterpene lactones have mainly focused on their bioactive potential rather than on their sensory properties. In the present study, we report about the stimulation of heterologously expressed human bitter taste receptors, hTAS2Rs, by the bitter sesquiterpene lactone herbolide D. A specific response to herbolide D was observed i.a. for hTAS2R46, a so far orphan bitter taste receptor without any known ligand. By further investigation of its agonist pattern, we characterized hTAS2R46 as a bitter receptor broadly tuned to sesquiterpene lactones and to clerodane and labdane diterpenoids as well as to the unrelated bitter substances strychnine and denatonium.

  16. Utilization of oxidation reactions for the spectrophotometric determination of captopril using brominating agents

    Science.gov (United States)

    El-Didamony, Akram M.; Erfan, Eman A. H.

    2010-03-01

    Three simple, accurate and sensitive methods (A-C) for the spectrophotometric assay of captopril (CPL) in bulk drug, in dosage forms and in the presence of its oxidative degradates have been described. The methods are based on the bromination of captopril with a solution of excess brominating mixture in hydrochloric acid medium. After bromination, the excess brominating mixture is followed by the estimation of surplus bromine by three different reaction schemes. In the first method (A), the determination of the residual bromine is based on its ability to bleach the indigo carmine dye and measuring the absorbance at 610 nm. Method B, involves treating the unreacted bromine with a measured excess of iron(II) and the remaining iron(II) is complexed with 1,10-phenanthroline and the increase in absorbance is measured at 510 nm. In method (C), the surplus bromine is treated with excess of iron(II) and the resulting iron(III) is complexed with thiocyanate and the absorbance is measured at 478 nm. In all the methods, the amount of bromine reacted corresponds to the drug content. The different experimental parameters affecting the development and stability of the color are carefully studied and optimized. Beer's law is valid within a concentration range of 0.4-6.0, 0.4-2.8 and 1.2-4.8 μg mL -1 for methods A, B and C, respectively. The calculated apparent molar absorptivity was found to be 5.16 × 10 4, 9.95 × 10 4 and 1.74 × 10 5 L mol -1 cm -1, for methods A, B and C, respectively. Sandell's sensitivity, correlation coefficients, detection and quantification limits are also reported. No interference was observed from common additives found in pharmaceutical preparations. The proposed methods are successfully applied to the determination of CPL in the tablet formulations with mean recoveries of 99.94-100.11% and the results were statistically compared with those of a reference method by applying Student's t- and F-test.

  17. Terminal elimination half-lives of the brominated flame retardants TBBPA, HBCD, and lower brominated PBDEs in humans

    Energy Technology Data Exchange (ETDEWEB)

    Geyer, H.J.; Schramm, K.W.; Feicht, E.A.; Fried, K.W.; Henkelmann, B.; Lenoir, D. [GSF-National Research Center, Institute of Ecological Chemistry, Neuherberg (Germany); Darnerud, P.O.; Aune, M. [Swedish National Food Administration, Uppsala (Sweden); Schmid, P. [Swiss Federal Laboratories for Materials Testing and Research, Laboratory of Organic Chemistry, EMPA Duebendorf (Switzerland); McDonald, T.A. [Office of Environmental Health Assessment, California EPA, Oakland, CA (United States)

    2004-09-15

    Brominated flame retardants (BFRs) are widely used in polymers and textiles and applied in electronic equipment, construction materials, and furniture for the purpose of fire prevention. BFRs with the highest production volume are tetrabromobisphenol A (TBBPA), 1,2,5,6,9,10- hexabromocyclododecanes (HBCDs: {alpha}-HBCD + {beta}-HBCD + {gamma}-HBCD), and polybrominated diphenyl ethers (PBDEs). Several BFRs are highly lipophilic persistent organic pollutants (POPs) which have been identified in the aquatic and terrestrial environment including wildlife and humans. In exposed organisms including humans toxic effects, bioaccumulation, metabolism, and pharmacokinetics (especially half-life t{sub 1/2}) are important criterions in the hazard assessment. The aim of the present study was to estimate the terminal elimination half-lives (t{sub 1/2H}) of the main BFRs from the whole body (also named body-burden half-life) and/or from the adipose tissue (fat) of adult humans. The t{sub 1/2H} data for the following BFRs were evaluated: TBBPA, HBCD, 2,2',4,4'- tetrabromodiphenyl ether (BDE-47), 2,2',4,4',5-pentaBDE (BDE-99), 2,2',4,4',6-pentaBDE (BDE- 100), 2,2',4,4',5,5'-hexaBDE (BDE-153), and 2,2',4,4',5,6-hexaBDE (BDE-154).

  18. A serial dual-electrode detector based on electrogenerated bromine for capillary electrophoresis.

    Science.gov (United States)

    Du, Fuying; Cao, Shunan; Fung, Ying-Sing

    2014-12-01

    A new serial dual-electrode detector for CE has been designed and fabricated for postcolumn reaction detection based on electrogenerated bromine. A coaxial postcolumn reactor was employed to introduce bromide reagent and facilitate the fabrication of upstream generation electrode by simply sputtering Pt film onto the outer surface of the separation capillary. Bromide introduced could be efficiently converted to bromine at this Pt film electrode and subsequently detected by the downstream Pt microdisk detection electrode. Analytes that react with bromine could be determined by the decrease of bromine reduction current at the downstream electrode resulting from the reaction between analytes and bromine. The effects of serial dual-electrode detector working conditions including electrode potentials, bromide flow rate, and bromide concentration on analytical performance were investigated using glutathione (GSH) and glutathione disulfide (GSSG) as test analytes. Under the optimal conditions, detection limits down to 0.16 μM for GSH and 0.14 μM for GSSG (S/N = 3) as well as linear working ranges of two orders of magnitude for GSH and GSSG were achieved. Furthermore, the separation efficiency obtained by our dual-electrode detector design was greatly improved compared with previous reported design. The developed method has been successfully applied to determine the GSH and GSSG impurity in commercial GSH supplement.

  19. Removal of brominated flame retardant from electrical and electronic waste plastic by solvothermal technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Cong-Cong [Research Center For Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Zhang, Fu-Shen, E-mail: fszhang@rcees.ac.cn [Research Center For Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China)

    2012-06-30

    Highlights: Black-Right-Pointing-Pointer A process for brominated flame retardants (BFRs) removal in plastic was established. Black-Right-Pointing-Pointer The plastic became bromine-free with the structure maintained after this treatment. Black-Right-Pointing-Pointer BFRs transferred into alcohol solvent were easily debrominated by metallic copper. - Abstract: Brominated flame retardants (BFRs) in electrical and electronic (E and E) waste plastic are toxic, bioaccumulative and recalcitrant. In the present study, tetrabromobisphenol A (TBBPA) contained in this type of plastic was tentatively subjected to solvothermal treatment so as to obtain bromine-free plastic. Methanol, ethanol and isopropanol were examined as solvents for solvothermal treatment and it was found that methanol was the optimal solvent for TBBPA removal. The optimum temperature, time and liquid to solid ratio for solvothermal treatment to remove TBBPA were 90 Degree-Sign C, 2 h and 15:1, respectively. After the treatment with various alcohol solvents, it was found that TBBPA was finally transferred into the solvents and bromine in the extract was debrominated catalyzed by metallic copper. Bisphenol A and cuprous bromide were the main products after debromination. The morphology and FTIR properties of the plastic were generally unchanged after the solvothermal treatment indicating that the structure of the plastic maintained after the process. This work provides a clean and applicable process for BFRs-containing plastic disposal.

  20. Effect of the Bromine-Based Flame Retardant Plastic Pyrolysis of Hydrotalcite

    Directory of Open Access Journals (Sweden)

    Morita N.

    2016-01-01

    Full Text Available In this study, a method is presented to decrease halogen compounds in the product oil from thermolysis of polystyrene and polypropylene mixed plastic spiked with tetrabromobisphenol A. A mixture of hydrotalcite and plastic was pyrolyzed in a glass reactor at 400 °C under a nitrogen atmosphere. Bromine compounds in the residual substances were measured. The yield of product oil increased using hydrotalcite as an additive. The bromine compounds that were the major ingredients in the oil after thermolysis at 400 °C from the mixed plastic, which also included toluene, ethyl benzene, styrene, and 1-methylethyl benzene, were 2-bromohexane, 3-bromo-1-propenyl benzene, 4,5-dibromodecane, 1-bromomethylbenzene, 3-bromophenol, and 4-bromo-2,6-dimethylbenzaniline. However, bromine compounds were not detected in the product oil, residue, or gas when hydrotalcite was added. After the thermolysis of the plastic, bromine compounds in the product oil may decrease because bromine was captured by the added hydrotalcite.

  1. GAS SORPTION AND TRANSPORT IN POLY (PHENYLENE OXIDE )(PPO)AND ARYL-BROMINATED PPO MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    JIA Lianda; F.R.SHEU, R.T. CHERN; H.B. HOPFENBERG

    1989-01-01

    The apparent solubility (S), concentration- average diffusivity (D), and permeability (P), for CO2,CH4 and N2 through PPO and aryl- brominated PPO at 35 ℃ for pressure ranging from 1 to 26 atm are reported. It is found that P,D, and Sof the membranes to all the three gases vary with the extent of bromination. S increases with the increase of the perecnt of bromine in each case, but D to CO2 increases remarkably only at higher degree of bromination, and therefore, P to CO2 is increased by more than 100% over a wide range of pressure in the case .The solubility data are well described by the dual mode sorption model. It is found that the gas molecules sorbed by the Langmuir mode are relatively more immobilized and the contribution of the nonequilibrium character of the polymer to gas permeation increases obviously for CO2 and is hardly changed for CH4 with increasing bromine content. These observations are interpreted in terms of changes in specific free volume (SFV)and the cohesive energy density (CED) of the polymers.

  2. Characterization of unknown brominated disinfection byproducts during chlorination using ultrahigh resolution mass spectrometry.

    Science.gov (United States)

    Zhang, Haifeng; Zhang, Yahe; Shi, Quan; Zheng, Hongdie; Yang, Min

    2014-03-18

    Brominated disinfection byproducts (Br-DBPs), formed from the reaction of disinfectant(s) with natural organic matter in the presence of bromide in raw water, are generally more cytotoxic and genotoxic than their chlorinated analogues. To date, only a few Br-DBPs in drinking water have been identified, while a significant portion of Br-DBPs in drinking water is still unknown. In this study, negative ion electrospray ionization ultrahigh resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) was used to characterize unknown Br-DBPs in artificial drinking water. In total, 441 formulas for one-bromine-containing products and 37 formulas for two-bromine-containing products, most of which had not been previously reported, were detected in the chlorinated sample. Most Br-DBPs have corresponding chlorine-containing analogues with identical CHO composition. In addition, on-resonance collision-induced dissociation (CID) of single ultrahigh resolved bromine containing mass peaks was performed in the ICR cell to isolate single bromine-containing components in a very complex natural organic matter spectrum and provide structure information. Relatively abundant neutral loss of CO2 was observed in MS-MS spectra, indicating that the unknown Br-DBPs are rich in carboxyl groups. The results demonstrate that the ESI FT-ICR MS method could provide valuable molecular composition and structure information on unknown Br-DBPs.

  3. Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine

    Science.gov (United States)

    Maselli, Olivia J.; Chellman, Nathan J.; Grieman, Mackenzie; Layman, Lawrence; McConnell, Joseph R.; Pasteris, Daniel; Rhodes, Rachael H.; Saltzman, Eric; Sigl, Michael

    2017-01-01

    Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH3SO3H) and bromine, covering the time period 1750-2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA levels decrease as a result of declining sea ice extent but bromine levels increase. We consider several possible explanations and ultimately suggest that increased acidity, specifically nitric acid, of snow on sea ice stimulates the release of reactive Br from sea ice, resulting in increased transport and deposition on the Greenland ice sheet.

  4. Isolation of a sesquiterpene synthase expressing in specialized epithelial cells surrounding the secretory cavities in rough lemon (Citrus jambhiri).

    Science.gov (United States)

    Uji, Yuya; Ozawa, Rika; Shishido, Hodaka; Taniguchi, Shiduku; Takabayashi, Junji; Akimitsu, Kazuya; Gomi, Kenji

    2015-05-15

    Volatile terpenoids such as monoterpenes and sesquiterpenes play multiple roles in plant responses and are synthesized by terpene synthases (TPSs). We have previously isolated a partial TPS gene, RlemTPS4, that responds to microbial attack in rough lemon. In this study, we isolated a full length RlemTPS4 cDNA from rough lemon. RlemTPS4 localized in the cytosol. The recombinant RlemTPS4 protein was obtained using a prokaryotic expression system and GC-MS analysis of the terpenes produced by the RlemTPS4 enzymatic reaction determined that RlemTPS4 produces some sesquiterpenes such as δ-elemene. The RlemTPS4 gene was specifically expressed in specialized epithelial cells surrounding the oil secretory cavities in rough lemon leaf tissue.

  5. Redifferentiation of human hepatoma cells (SMMC-7721) induced by two new highly oxygenated bisabolane-type sesquiterpenes

    Indian Academy of Sciences (India)

    Ruidong Miao; Juan Wei; Q I Zhang; Venkateswara Sajja; Jinbo Yang; Qin Wang

    2008-12-01

    Bisabolane-type sesquiterpenes are a class of biologically active compounds that has antitumour, antifungal, antibacterial, antioxidant and antivenom properties. We investigated the effect of two new highly oxygenated bisabolane-type sesquiterpenes (HOBS) isolated from Cremanthodium discoideum (C. discoideum) on tumour cells. Our results showed that HOBS induced morphological differentiation and reduced microvilli formation on the cell surface in SMMC-7721 cells. Flow cytometry analysis demonstrated that HOBS could induce cell-cycle arrest in the G1 phase. Moreover, HOBS was able to increase tyrosine--ketoglutarate transaminase activity, decrease -foetoprotein level and -glutamyl transferase activity. In addition, we found that HOBS inhibited the anchorage-independent growth of SMMC-7721 cells in a dose-dependent manner. Taken together, all the above observations indicate that HOBS might be able to normalize malignant SMMC-7721 cells by inhibiting cell proliferation and inducing redifferentiation.

  6. The NBS Reaction: A Simple Explanation for the Predominance of Allylic Substitution over Olefin Addition by Bromine at Low Concentrations.

    Science.gov (United States)

    Wamser, Carl C.; Scott, Lawrence T.

    1985-01-01

    Examines mechanisms related to use of N-bromosuccinimide (NBS) for bromination at an allylic position. Also presents derived rate laws for three possible reactions of molecular bromine with an alkene: (1) free radical substitution; (2) free radical addition; and (3) electrophilic addition. (JN)

  7. Influence of temperature and heating time on bromination of zinc oxide during thermal treatment with tetrabromobisphenol A.

    Science.gov (United States)

    Grabda, Mariusz; Oleszek-Kudlak, Sylwia; Shibata, Etsuro; Nakamura, Takashi

    2009-12-01

    Our prior research indicates that hydrogen bromide (HBr) evolved during thermal decomposition of tetrabromobisphenol A (TBBPA) can be utilized as a reagent for selective bromination and evaporation of zinc oxide. The present work investigated dependency of the bromination reaction on time at selected temperatures using a laboratory-scale furnace. The formed solid, condensed, and gaseous products were analyzed by X-ray diffraction analysis, electron probe microanalysis, inductively coupled plasma analysis, ion chromatography, and gas chromatography coupled with mass spectrometry. Results indicate that the bromination rate is strongly dependent on heating time. This dependency is a direct consequence of progress in the decomposition of TBBPA, which provides inorganic bromine suitable for the reaction. The bromination rate increases with time until the bromine source is depleted. The process is shorter at higher applied temperatures and appears instantaneous at 310 degrees C and above. However, the maximum bromination yield is independent of the applied conditions and ranges from 64 to 70%. Additionally, the influence of oxidizing conditions on the bromination reaction and the effect of ZnO on decomposition of TBBPA were investigated in this study.

  8. Synthesis of 2-arylbenzimidazoles and 2-arylbenzothiazoles in both room temperature and microwave condition catalyzed by hexamethylenetetramine-bromine complex

    Institute of Scientific and Technical Information of China (English)

    Kaveh Khosravi; Samira Kazemi

    2012-01-01

    One-pot condensation of 2-aminothiophenol or 1,2-phenylenediamine with different aldehydes has been catalyzed by hexamethylenetetramine-bromine (HMTA-Bromine) as new,available and effective catalyst.2-Arylbenzo thiazoles and 2-aryl benzimidazoles have been achieved in excellent yield and good purity.

  9. Nitrated and Brominated Narcotine and its Cleaved Adduct as Butyrylcholinesterase Inhibitors

    Directory of Open Access Journals (Sweden)

    M. A. Abbasi

    2013-09-01

    Full Text Available Narcotine is a very antitussive agent and its modification may lead to some more biological activities. In this presented paper, narcotine (1 was first subjected to nitration and bromination to yield nitrated narcotine (2 and brominated narcotine (3. It was further made to react with phenylchloroformate (6 to give a cleaved addition product 4. This adduct 4 was further nitrated and brominated to yield substituted derivatives 5 and 6, respectively. The structure elucidation of the synthesized compounds was processed via IR, EI-MS and 1H-NMR spectra. These were also screened against butyrylcholinesterase enzyme and were found to the moderate inhibitors of butyrylcholinesterase except nitrated product, 2, of narcotine (1.

  10. The separation of waste printed circuit board by dissolving bromine epoxy resin using organic solvent.

    Science.gov (United States)

    Zhu, P; Chen, Y; Wang, L Y; Zhou, M; Zhou, J

    2013-02-01

    Separation of waste printed circuit boards (WPCBs) has been a bottleneck in WPCBs resource processing. In this study, the separation of WPCBs was performed using dimethyl sulfoxide (DMSO) as a solvent. Various parameters, which included solid to liquid ratio, temperature, WPCB sizes, and time, were studied to understand the separation of WPCBs by dissolving bromine epoxy resin using DMSO. Experimental results showed that the concentration of dissolving the bromine epoxy resin increased with increasing various parameters. The optimum condition of complete separation of WPCBs was solid to liquid ratio of 1:7 and WPCB sizes of 16 mm(2) at 145°C for 60 min. The used DMSO was vapored under the decompression, which obtained the regenerated DMSO and dissolved bromine epoxy resin. This clean and non-polluting technology offers a new way to separate valuable materials from WPCBs and prevent the environmental pollution of waste printed circuit boards effectively.

  11. Improved charge carrier lifetime in planar perovskite solar cells by bromine doping

    Science.gov (United States)

    Kiermasch, David; Rieder, Philipp; Tvingstedt, Kristofer; Baumann, Andreas; Dyakonov, Vladimir

    2016-12-01

    The charge carrier lifetime is an important parameter in solar cells as it defines, together with the mobility, the diffusion length of the charge carriers, thus directly determining the optimal active layer thickness of a device. Herein, we report on charge carrier lifetime values in bromine doped planar methylammonium lead iodide (MAPbI3) solar cells determined by transient photovoltage. The corresponding charge carrier density has been derived from charge carrier extraction. We found increased lifetime values in solar cells incorporating bromine compared to pure MAPbI3 by a factor of ~2.75 at an illumination intensity corresponding to 1 sun. In the bromine containing solar cells we additionally observe an anomalously high value of extracted charge, which we deduce to originate from mobile ions.

  12. Identification of sesquiterpene coumarins of oleo-gum resin of Ferula assa-foetida L. from the Yasuj region.

    Science.gov (United States)

    Asghari, J; Atabaki, V; Baher, E; Mazaheritehrani, M

    2016-01-01

    Chemical investigation of the oleo-gum resin of Ferula assa-foetida L. from Yasuj region led to the identification of five sesquiterpene coumarins namely, conferone (1), badrakemin (2), feslol (3), isosamarcandin (4) and samarcandin (5). The compounds were characterised by detailed 1D ((1)H and (13)C) and 2D NMR (HMBC, HSQC and NOESY) experiments. Among these compounds, conferone (1) and isosamarcandin (4) are being newly reported in F. assa-foetida L.

  13. Role of the Colletotrichum acutatum sesquiterpene synthase CaTPS in the biosynthesis of sesquiterpenoids

    DEFF Research Database (Denmark)

    Amby, Daniel Buchvaldt; Manczak, Tom; Petersen, Mikael Agerlin;

    2016-01-01

    biosynthesis is performed by sesquiterpene synthases (TPS). Only a few TPSs have been functionally characterized from filamentous fungi and none from the genus Colletotrichum. Despite being an important fungal pathogen to agriculture, it is poorly understood at the molecular and chemical levels. The terpenoid...... characterization of TPS in Colletotrichum spp. and terpenoid profiles of Coll. acutatum, which could facilitate studies on the role of terpenoids in the ecology of Coll. acutatum....

  14. Investigation of the Antiproliferative Properties of Natural Sesquiterpenes from Artemisia asiatica and Onopordum acanthium on HL-60 Cells in Vitro

    Directory of Open Access Journals (Sweden)

    Judit Molnár

    2016-02-01

    Full Text Available Plants and plant extracts play a crucial role in the research into novel antineoplastic agents. Four sesquiterpene lactones, artecanin (1, 3β-chloro-4α,10α-dihydroxy-1α,2α-epoxy-5α,7αH-guaia-11(13-en-12,6α-olide (2, iso-seco-tanapartholide 3-O-methyl ether (3 and 4β,15-dihydro-3-dehydrozaluzanin C (4, were isolated from two traditionally used Asteraceae species (Onopordum acanthium and Artemisia asiatica. When tested for antiproliferative action on HL-60 leukemia cells, these compounds exhibited reasonable IC50 values in the range 3.6–13.5 μM. Treatment with the tested compounds resulted in a cell cycle disturbance characterized by increases in the G1 and G2/M populations, while there was a decrease in the S phase. Additionally, 1–3 elicited increases in the hypodiploid (subG1 population. The compounds elicited concentration-dependent chromatin condensation and disruption of the membrane integrity, as revealed by Hoechst 33258–propidium staining. Treatment for 24 h resulted in significant increases in activity of caspases-3 and -9, indicating that the tested sesquiterpenes induced the mitochondrial pathway of apoptosis. The proapoptotic properties of the sesquiterpene lactones were additionally demonstrated withannexin V staining. Compounds 1 and 2 increased the Bax/Bcl-2 expression and decreased the expressions of CDK1 and cyclin B2, as determined at the mRNA level by means of RT-PCR. These experimental results indicate that sesquiterpene lactones may be regarded as potential starting structures for the development of novel anticancer agents.

  15. Bromination of Marine Dissolved Organic Matter following Full Scale Electrochemical Ballast Water Disinfection.

    Science.gov (United States)

    Gonsior, Michael; Mitchelmore, Carys; Heyes, Andrew; Harir, Mourad; Richardson, Susan D; Petty, William Tyler; Wright, David A; Schmitt-Kopplin, Philippe

    2015-08-01

    An extensively diverse array of brominated disinfection byproducts (DBPs) were generated following electrochemical disinfection of natural coastal/estuarine water, which is one of the main treatment methods currently under consideration for ballast water treatment. Ultra-high-resolution mass spectrometry revealed 462 distinct brominated DBPs at a relative abundance in the mass spectra of more than 1%. A brominated DBP with a relative abundance of almost 22% was identified as 2,2,4-tribromo-5-hydroxy-4-cyclopentene-1,3-dione, which is an analogue to several previously described 2,2,4-trihalo-5-hydroxy-4-cyclopentene-1,3-diones in drinking water. Several other brominated molecular formulas matched those of other known brominated DBPs, such as dibromomethane, which could be generated by decarboxylation of dibromoacetic acid during ionization, dibromophenol, dibromopropanoic acid, dibromobutanoic acid, bromohydroxybenzoic acid, bromophenylacetic acid, bromooxopentenoic acid, and dibromopentenedioic acid. Via comparison to previously described chlorine-containing analogues, bromophenylacetic acid, dibromooxopentenoic acid, and dibromopentenedioic acid were also identified. A novel compound at a 4% relative abundance was identified as tribromoethenesulfonate. This compound has not been previously described as a DBP, and its core structure of tribromoethene has been demonstrated to show toxicological implications. Here we show that electrochemical disinfection, suggested as a candidate for successful ballast water treatment, caused considerable production of some previously characterized DBPs in addition to novel brominated DBPs, although several hundred compounds remain structurally uncharacterized. Our results clearly demonstrate that electrochemical and potentially direct chlorination of ballast water in estuarine and marine systems should be approached with caution and the concentrations, fate, and toxicity of DBP need to be further characterized.

  16. Investigation of Mercury Vapor Treatment by Activated Carbon Made from Coconut Shell and Denatured by Elemental Bromine

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    Tran Hong Con

    2015-07-01

    Full Text Available Coconut shell activated carbon of TraVinhcompany, Vietnam was oxidized by bromine solution at pH 4-6 in normal temperature and pressure. The efficiency of bromine carried on AC surface reached 70.95 to 98.50%. The IR spectrum showed that in surface of the brominated AC appeared C-Br, carbonyl and carboxyl groups. The adsorption capacity of brominated AC reached more than 130 mg/g at 40oC and mercury concentration around 32 mg/m3. The mercury vapor adsorption of the material was almost uninfluenced by experimental temperature. Used brominated AC can be regenerated and recovered mercury metal. The regenerated material has adsorption capacity of 86.92% in comparison with initial material and weight loss was 6.23% at laboratory scale examination.

  17. Tandem Mass Spectrometry for Structural Identification of Sesquiterpene Alkaloids from the Stems of Dendrobium nobile Using LC-QToF.

    Science.gov (United States)

    Wang, Yan-Hong; Avula, Bharathi; Abe, Naohito; Wei, Feng; Wang, Mei; Ma, Shuang-Cheng; Ali, Zulfiqar; Elsohly, Mahmoud A; Khan, Ikhlas A

    2016-05-01

    Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine. Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chromatographic methods. Herein, tandem mass spectrometry combined with liquid chromatography separation provides a tool for the identification and characterization of the alkaloids from D. nobile. A total of nine sesquiterpene alkaloids were characterized by ultrahigh-performance liquid chromatography tandem mass spectrometry. These alkaloids can be classified into two subgroups that are represented by dendrobine and nobilonine. Tandem mass spectrometric studies revealed the fragmentation pathways of these two subgroup alkaloids that were used for the identification and characterization of other alkaloids in D. nobile. Characterization of these alkaloids using accurate mass and diagnostic fragments provided a reliable methodology for the analysis of D. nobile by ultrahigh-performance liquid chromatography tandem mass spectrometry. The limit of detection was defined as the signal-to-noise ratio equal to 3 : 1. Limits of detection of dendrobine and nobilonine were less than 30 ng/mL. The developed method was applied for the analysis of various Dendrobium species and related dietary supplements. Alkaloids were identified from D. nobile, but not detected from commercial samples including 13 other Dendrobium species and the 7 dietary supplements.

  18. Measurement of atmospheric sesquiterpenes by proton transfer reaction-mass spectrometry (PTR-MS

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    A. Guenther

    2009-04-01

    Full Text Available The ability to measure sesquiterpenes (SQT; C15H24 by a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS was investigated. SQT calibration standards were prepared by a capillary diffusion method and the PTR-MS-estimated mixing ratios were derived from the counts of product ions and proton transfer reaction constants. These values were compared with mixing ratios determined by a calibrated Gas Chromatograph (GC coupled to a Flame Ionization Detector (GC-FID. Product ion distributions from soft-ionization occurring in a selected ion drift tube via proton transfer were measured as a function of collision energies. Results after the consideration of the mass discrimination of the PTR-MS system suggest that quantitative SQT measurements within 20% accuracy can be achieved with PTR-MS if two major product ions (m/z 149+ and 205+, out of seven major product ions (m/z 81+, 95+, 109+, 123+, 135+, 149+ and 205+, are accounted for. Considerable fragmentation of bicyclic sesquiterpenes, i.e. β-caryophyllene and α-humulene, cause the accuracy to be reduced to 50% if only the parent ion (m/z 205+ is considered. These findings were applied to a field dataset collected above a deciduous forest at the PROPHET (Program for Research on Oxidants: Photochemistry, Emissions, and Transport research station in 2005. Inferred average daytime ecosystem scale mixing ratios (fluxes of isoprene, sum of monoterpenes (MT, and sum of SQT exhibited values of 15 μg m−3 (4.5 mg m−2 h−1, 1.2 μg m−3 (0.21 mg m−2 h−1, and 0.0016 μg m−3 (0.10 mg m−2 h−1, respectively. A range of MT and SQT reactivities with respect to the OH radical was calculated and compared to an earlier study inferring significantly

  19. Measurement of atmospheric sesquiterpenes by proton transfer reaction-mass spectrometry (PTR-MS

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    S. Kim

    2008-12-01

    Full Text Available The ability to measure sesquiterpenes (SQT; C15H24 by a Proton-Transfer-Reaction Mass Spectrometer (PTR-MS was investigated with SQT standards, prepared by a capillary diffusion method, and the estimated mixing ratios, derived from the counts of product ions and proton transfer reaction constants were intercompared with measured mixing ratios, measured by a complementary Gas Chromatograph (GC coupled to a Flame Ionization Detector (GC-FID. Product ion distributions due to soft-ionization occurring in a selected ion drift tube via proton transfer were measured as a function of collision energies. Results after the consideration of the mass discrimination of the PTR-MS system suggest that quantitative SQT measurements within 20% accuracy can be achieved with PTR-MS if two major product ions (m/z 149+ and 205+ out of seven major product ions (m/z 81+, 95+, 109+, 123+, 135+, 149+ and 205+ are accounted for. Bicyclic sesquiterpenes, i.e. β-caryophyllene and α-humulene, showed considerable fragmentation causing the accuracy of their analysis to be reduced to 50% if only the parent ion (m/z 205 is considered. These findings were applied to a field dataset collected above a deciduous forest at the PROPHET (Program for Research on Oxidants: Photochemistry, Emissions, and Transport research station in 2005. Inferred Average daytime ecosystem scale mixing ratios (fluxes of isoprene, sum of monoterpenes (MT, and sum of SQT exhibited values of 15 μg m−3 (4.5 mg m−2 h−1, 1.2 μg m−3 (0.21 mg m−2 h−1 and 0.0016 μg m−3 (0.10 mgm−2 h−1 respectively. A range of MT and SQT reactivities with respect to the OH radical was calculated and compared to an earlier study inferring significantly underestimated OH

  20. A Quaternized Polysulfone Membrane for Zinc-Bromine Redox Flow Battery

    OpenAIRE

    Mingqiang Li; Hang Su; Qinggang Qiu; Guang Zhao; Yu Sun; Wenjun Song

    2014-01-01

    A quaternized polysulfone (QNPSU) composite membrane is fabricated for zinc-bromine redox flow battery. The structure of the membrane is examined by FT-IR spectra and SEM. The conductivity of the membrane is tested by electrochemical analyzer. After a zinc-bromine battery with this composite membrane is operated at different voltage while charging and at different current while discharging to examine the performance of the membrane, it is found that the discharge voltage was 0.9672 V and the ...

  1. Contribution of very short-lived substances to stratospheric bromine loading: uncertainties and constraints

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    J. Aschmann

    2013-02-01

    Full Text Available Very short-lived substances (VSLS still represent a major factor of uncertainty in the quantification of stratospheric bromine loading. One of the major obstacles for short-lived source gases in contributing to the stratosphere is generally thought to be loss of inorganic bromine (Bry in the tropical tropopause layer (TTL due to dehydration. We use sensitivity calculations with a three-dimensional chemistry transport model comprising a consistent parametrization of convective transport and a comprehensive chemistry scheme to investigate the associated processes. The model considers the two most important bromine VSLS, bromoform (CHBr3 and dibromomethane (CH2Br2. The organic bromine source gases as well as the resulting profile of inorganic bromine in the model are consistent with available observations. In contrast to its organic precursors, Bry is assumed to have a significant sorption capacity regarding sedimenting liquid or frozen particles thus the fraction of intact source gases during their ascent through the TTL is a critical factor. We find that source gas injection is the dominant pathway into the stratosphere, about 50% of CHBr3 and 94% of CH2Br2 is able to overcome the cold point tropopause at approximately 17 km altitude, modulated by the interannual variability of the vertical transport efficiency. In fact, our sensitivity calculations indicate that the extent of source gas injection of CHBr3 is highly sensitive to the strength of convection and large-scale ascent; in contrast, modifying the photolysis or the destruction via OH yields a significantly smaller response. In principle, the same applies as well to CH2Br2, though it is considerably less responsive due to its longer lifetime. The next important aspect we identified is that the partitioning of available Bry from short-lived sources is clearly

  2. Contribution of very short-lived substances to stratospheric bromine loading: uncertainties and constraints

    Directory of Open Access Journals (Sweden)

    J. Aschmann

    2012-11-01

    Full Text Available Very short-lived substances (VSLS still represent a major factor of uncertainty in the quantification of stratospheric bromine loading. One of the major obstacles for short-lived source gases in contributing to the stratosphere is generally thought to be loss of inorganic bromine (Bry in the tropical tropopause layer (TTL due to dehydration. We use sensitivity calculations with a~three-dimensional chemistry transport model comprising a consistent parametrization of convective transport and a comprehensive chemistry scheme to investigate the associated processes. The model considers the two most important bromine VSLS, bromoform (CHBr3 and dibromomethane (CH2Br2. The organic bromine source gases as well as the resulting profile of inorganic bromine in the model are consistent with available observations. In contrast to its organic precursors, Bry is assumed to have a~significant sorption capacity regarding sedimenting liquid or frozen particles thus the fraction of intact source gases during their ascent through the TTL is a critical factor. We find that source gas injection is the dominant pathway into the stratosphere, about 50% of CHBr3 and 93% of CH2Br2 is able to overcome the cold point tropopause at approximately 17 km altitude, modulated by the interannual variability of the vertical transport efficiency. In fact, our sensitivity calculations indicate that the extent of source gas injection of CHBr3 is highly sensitive to the strength of convection and large-scale ascent; in contrast, modifying the photolysis or the destruction via OH yields a significantly smaller response. In principal, the same applies as well to CH2Br2, though it is considerably less responsive due to its longer lifetime. The next important aspect we identified is that the partitioning of available Bry from short-lived sources is clearly

  3. Antiplasmodial Activity of Aporphine Alkaloids and Sesquiterpene Lactones from Liriodendron tulipifera L

    Science.gov (United States)

    Graziose, Rocky; Rathinasabapathy, Thirumurugan; Lategan, Carmen; Poulev, Alexander; Smith, Peter J; Grace, Mary; Lila, Mary Ann; Raskin, Ilya

    2010-01-01

    Aim of the study The objective of this study was to isolate and characterize the active constituents of the traditionally used antimalarial plant Liriodendron tulipifera by antiplasmodial-assay guided fractionation. Materials and methods Bark and leaves were extracted with solvents of increasing polarity. Fractions were generated using flash chromatography, counter current chromatography and preparative HPLC and subjected to in vitro antiplasmodial and cytotoxicity assays. Active fractions were subjected to further fractionation until pure compounds were isolated, for which the IC50 values were calculated. Results and discussion Six known aporphine alkaloids, asimilobine (1), norushinsunine (2), norglaucine (3), liriodenine (4), anonaine (5) and oxoglaucine (6) were found to be responsible for the antiplasmodial activity of the bark. Leaves yielded two known sesquiterpene lactones, peroxyferolide (7) and lipiferolide (8) with antiplasmodial activity. The antiplasmodial activity of (2) (IC50 = 29.6 μg/ml), (3) (IC50 = 22.0 μg/ml), (6) (IC50= 9.1 μg/mL), (7) (IC50 = 6.2 μg/ml) and (8) (IC50 = 1.8 μg/ml) are reported for the first time. Conclusion This work supports the historical use of Liriodendron tulipifera as an antimalarial remedy of the United States and characterizes its antiplasmodial constituents. PMID:20826204

  4. Nerolidol: A Sesquiterpene Alcohol with Multi-Faceted Pharmacological and Biological Activities

    Directory of Open Access Journals (Sweden)

    Weng-Keong Chan

    2016-04-01

    Full Text Available Nerolidol (3,7,11-trimethyl-1,6,10-dodecatrien-3-ol is a naturally occurring sesquiterpene alcohol that is present in various plants with a floral odor. It is synthesized as an intermediate in the production of (3E-4,8-dimethy-1,3,7-nonatriene (DMNT, a herbivore-induced volatile that protects plants from herbivore damage. Chemically, nerolidol exists in two geometric isomers, a trans and a cis form. The usage of nerolidol is widespread across different industries. It has been widely used in cosmetics (e.g., shampoos and perfumes and in non-cosmetic products (e.g., detergents and cleansers. In fact, U.S. Food and Drug Administration (FDA has also permitted the use of nerolidol as a food flavoring agent. The fact that nerolidol is a common ingredient in many products has attracted researchers to explore more medicinal properties of nerolidol that may exert beneficial effect on human health. Therefore, the aim of this review is to compile and consolidate the data on the various pharmacological and biological activities displayed by nerolidol. Furthermore, this review also includes pharmacokinetic and toxicological studies of nerolidol. In summary, the various pharmacological and biological activities demonstrated in this review highlight the prospects of nerolidol as a promising chemical or drug candidate in the field of agriculture and medicine.

  5. Inactivation of the cytotoxic activity of repin, a sesquiterpene lactone from Centaurea repens.

    Science.gov (United States)

    Tukov, Francis F; Anand, S; Gadepalli, Rama Sarma V S; Gunatilaka, A A Leslie; Matthews, John C; Rimoldi, John M

    2004-09-01

    Prolonged ingestion of Yellow Starthistle (Centaurea solstitialis) and Russian Knapweed (Centaurea repens) by horses has been shown to result in a fatal neurodegenerative disorder called equine nigropallidal encephalomalacia (ENE). Bioassay-guided fractionation of extracts from Centaurea species using the PC12 cell line have led to the identification of one of several putative agents, which may contribute to ENE, namely, the sesquiterpene lactone (SQL) repin (1), previously linked to ENE due to its abundance in C. repens. To characterize the molecular basis of repin-induced neurotoxicity, the present study was designed to identify reactive functional groups that may contribute overall to its toxicity. The reaction of repin (1) with glutathione (GSH) led to the exclusive addition of GSH to the alpha-methylenebutyrolactone affording a GSH conjugate (3b) that lacked toxicity in the PC12 cell assay, while selective reduction of the alpha-methylenebutyrolactone double bond of 1 also resulted in an analogue (2) that was devoid of toxicity relative to the parent compound. Unlike repin, analogue 2 failed to decrease cellular dopamine levels in PC12 cells, further substantiating the requirement of the alpha-methylenebutyrolactone group. Results from this study are suggestive that GSH depletion by the SQL repin may be a primary event in the etiology of ENE, increasing the susceptibility to oxidative damage.

  6. Effect of the sesquiterpene lactone incomptine A in the energy metabolism of Entamoeba histolytica.

    Science.gov (United States)

    Velázquez-Domínguez, José; Marchat, Laurence A; López-Camarillo, Cesar; Mendoza-Hernández, Guillermo; Sánchez-Espíndola, Esther; Calzada, Fernando; Ortega-Hernández, Alfredo; Sánchez-Monroy, Virginia; Ramírez-Moreno, Esther

    2013-11-01

    Entamoeba histolytica is the causative agent of human amoebiasis, which mainly affects developing countries. Although several drugs are effective against E. histolytica trophozoites, the control of amoebiasis requires the development of new and better alternative therapies. Medicinal plants have been the source of new molecules with remarkable antiprotozoal activity. Incomptine A isolated from Decachaeta incompta leaves, is a sesquiterpene lactone of the heliangolide type which has the major in vitro activity against E. histolytica trophozoites. However the molecular mechanisms involved in its antiprotozoal activity are still unknown. Using a proteomic approach based on two-dimensional gel electrophoresis and mass spectrometry (ESI-MS/MS) analysis, we evidenced that 21 E. histolytica proteins were differentially expressed in response to incomptine A treatment. Notably, three glycolytic enzymes, namely enolase, pyruvate:ferredoxin oxidoreductase and fructose-1,6-biphosphate aldolase, were down-regulated. Moreover, ultrastructural analysis of trophozoites through electronic microscopy showed an increased number of glycogen granules. Taken together, our data suggested that incomptine A could affect E. histolytica growth through alteration of its energy metabolism.

  7. From wine to pepper: rotundone, an obscure sesquiterpene, is a potent spicy aroma compound.

    Science.gov (United States)

    Wood, Claudia; Siebert, Tracey E; Parker, Mango; Capone, Dimitra L; Elsey, Gordon M; Pollnitz, Alan P; Eggers, Marcus; Meier, Manfred; Vössing, Tobias; Widder, Sabine; Krammer, Gerhard; Sefton, Mark A; Herderich, Markus J

    2008-05-28

    An obscure sesquiterpene, rotundone, has been identified as a hitherto unrecognized important aroma impact compound with a strong spicy, peppercorn aroma. Excellent correlations were observed between the concentration of rotundone and the mean 'black pepper' aroma intensity rated by sensory panels for both grape and wine samples, indicating that rotundone is a major contributor to peppery characters in Shiraz grapes and wine (and to a lesser extent in wine of other varieties). Approximately 80% of a sensory panel were very sensitive to the aroma of rotundone (aroma detection threshold levels of 16 ng/L in red wine and 8 ng/L in water). Above these concentrations, these panelists described the spiked samples as more 'peppery' and 'spicy'. However, approximately 20% of panelists could not detect this compound at the highest concentration tested (4000 ng/L), even in water. Thus, the sensory experiences of two consumers enjoying the same glass of Shiraz wine might be very different. Rotundone was found in much higher amounts in other common herbs and spices, especially black and white peppercorns, where it was present at approximately 10000 times the level found in very 'peppery' wine. Rotundone is the first compound found in black or white peppercorns that has a distinctive peppery aroma. Rotundone has an odor activity value in pepper on the order of 50000-250000 and is, on this criterion, by far the most powerful aroma compound yet found in that most important spice.

  8. Cloning and expression of sesquiterpene synthase genes from lettuce (Lactuca sativa L.).

    Science.gov (United States)

    Bennett, Mark H; Mansfield, John W; Lewis, Mervyn J; Beale, Michael H

    2002-06-01

    Sesquiterpenoid lactones (SLs) from lettuce (Lactuca sativa L.) include constitutive components of latex such as lactucin and the induced phytoalexin, lettucenin A. A redundant primer strategy was used to recover two full length cDNA clones (LTC1 and LTC2) encoding sesquiterpene synthases from a cDNA library derived from seedlings with the red spot disorder, which accumulate phytoalexins. Recombinant enzymes produced from LTC1 and LTC2 in Escherichia coli catalysed the cyclisation of farnesyl diphosphate to germacrene A, potentially an early step in the biosynthesis of SLs. RT-PCR analysis showed LTC1 and LTC2 were expressed constitutively in roots, hypocotyls and true leaves but not in cotyledons. Expression in cotyledons was induced by challenge with the downy mildew pathogen Bremia lactucae in the disease resistant cultivar Diana. Southern hybridisation experiments showed that LTC1 and LTC2 were not part of a multigene family. The germacrene A synthases provide targets for modified expression to generate beneficial modifications to the SL profile in lettuce.

  9. Generation of anti-trypanosomal agents through concise synthesis and structural diversification of sesquiterpene analogues.

    Science.gov (United States)

    Oguri, Hiroki; Hiruma, Takahisa; Yamagishi, Yutaka; Oikawa, Hideaki; Ishiyama, Aki; Otoguro, Kazuhiko; Yamada, Haruki; Ōmura, Satoshi

    2011-05-11

    To access high-quality small-molecule libraries to screen lead candidates for neglected diseases exemplified by human African trypanosomiasis, we sought to develop a synthetic process that would produce collections of cyclic scaffolds relevant to an assortment of natural products exhibiting desirable biological activities. By extracting the common structural features among several sesquiterpenes, including artemisinin, anthecularin, and transtaganolides, we designed six types of scaffolds with systematic structural variations consisting of three types of stereochemical relationships on the sp(3) ring-junctions and two distinct arrays of tricyclic frameworks. A modular and stereodivergent assembly of dienynes exploiting a versatile manifold produced a series of cyclization precursors. Divergent cyclizations of the dienynes employing tandem ring-closing metathesis reactions overrode variant reactivities of the cyclization precursors, leading to the six canonical sets of the tricyclic scaffolds incorporating a diene group. Screenings of trypanosomal activities of the canonical sets, as well as regio- and stereoisomers of the tricyclic dienes, allowed generation of several anti-trypanosomal agents defining the three-dimensional shape of the pharmacophore. The candidate tricyclic dienes were selected by primary screenings and further subjected to installation of a peroxide bridge, which generated artemisinin analogues that exhibited potent in vitro anti-trypanosomal activities comparable or even superior to those of artemisinin and the approved drugs, suramin and eflornithine.

  10. New sesquiterpene lactones from Arnica tincture prepared from fresh flowerheads of Arnica montana.

    Science.gov (United States)

    Kos, Olha; Lindenmeyer, Maja T; Tubaro, Aurelia; Sosa, Silvio; Merfort, Irmgard

    2005-11-01

    Investigation of an ethanolic extract prepared from fresh Arnica montana flowers afforded three new 1,5- trans-guaianolides, of which 11alpha,13-dihydro-2-O-tigloylflorilenalin and the respective 2-O-isovaleryl derivative are reported for the first time. Additionally, three new and one known 2beta-ethoxy-2,3-dihydrohelenalin esters were isolated. GC/MS studies of the extract after a two year storage at 4 degrees C demonstrated that the latter were artefacts that had been formed by addition of ethanol to the cyclopentenone structure of helenalin. Formation of these adducts gave compounds possessing an inhibitory activity comparable to that of 11alpha,13-dihydrohelenalin derivatives in the NF-kappaB EMSA and the IL-8 ELISA in vitro assays as well as in the in vivo croton oil-induced mouse ear edema test for one adduct, namely 2beta-ethoxy-6-O-acetyl-2,3-dihydrohelenalin. As expected, 6-O-(2-methylbutyryl)- and 6-O-methacryloyl-helenalin exhibited a stronger activity in the NF-kappaB EMSA and IL-8 ELISA. Sesquiterpene lactones seem to be the most important NF-kappaB inhibiting compounds in the Arnica extract. Bioguided fractionation using the luciferase reporter gene assay resulted in the isolation of only moderately active compounds, such as 6-acetoxy-2,2-dimethylchroman-4-one and 10-acetoxy-8,9-epoxythymol isobutyrate.

  11. Variation of sesquiterpene lactone contents in different Arnica montana populations: influence of ecological parameters.

    Science.gov (United States)

    Seemann, Andreas; Wallner, Teresa; Poschlod, Peter; Heilmann, Jörg

    2010-05-01

    In ten grassland or heathland sites along a geographic (north to south) and climatic gradient in Germany, flowerheads of Arnica montana were collected, and the total content of sesquiterpene lactones (SLs) as well as the content of the detected single compounds were determined. The ratios of helenalin (H)- and corresponding 11 alpha,13-dihydrohelenalin(DH)-type compounds were calculated. All habitats were characterised concerning the climatic and soil conditions, and the values obtained were correlated with SL contents according to univariate statistical analyses. All populations showed very similar and constant ratios of helenalin ( 1)/11 alpha,13-dihydrohelenalin ( 2) at around 1.5-2/1 irrespective of different ecological parameters. The ratio of helenalin/11 alpha,13-dihydrohelenalin esters was several fold higher in all samples, but it was nearly identical in every habitat among each other, except for the helenalin/11 alpha,13-dihydrohelenalin 2-methylbutyrate pair ( 5/ 11), which showed a constantly twofold higher H/DH ratio. However, the 6- O-isovalerylhelenalin content ( 6) showed highly significant correlations to climatic factors.

  12. Sesquiterpene lactones in Arnica montana: helenalin and dihydrohelenalin chemotypes in Spain.

    Science.gov (United States)

    Perry, Nigel B; Burgess, Elaine J; Rodríguez Guitián, Manuel A; Romero Franco, Rosa; López Mosquera, Elvira; Smallfield, Bruce M; Joyce, Nigel I; Littlejohn, Roger P

    2009-05-01

    An analytical RPLC method for sesquiterpene lactones in Arnica montana has been extended to include quantitative analyses of dihydrohelenalin esters. LC-ESI-MS-MS distinguished the isomeric helenalin and dihydrohelenalin esters. The dihydrohelenalin esters have lower response factors for UV detection than do helenalin esters, which must be taken into account for quantitative analyses. Analyses of flowers from 16 different wild populations of A. montana in Spain showed differing proportions of helenalin and dihydrohelenalin esters. For the first time a chemotype with high levels of helenalin esters (total helenalins 5.2-10.3 mg/g dry weight) is reported in Spanish A. montana. These samples were from heath lands at high altitude (1330-1460 m), whereas samples from meadows and peat bogs at lower altitudes were the expected chemotype with high levels of dihydrohelenalin esters (total dihydrohelenalins 10.9-18.2 mg/g). The phenolic compounds, both flavonoid glycosides and caffeoylquinic acids, in Spanish A. montana are reported for the first time. The levels of several of these compounds differed significantly between samples from heath lands and samples from peat bogs or meadows, with the heath land samples being most similar to central European A. montana in their phenolic composition.

  13. Quantification of Sesquiterpene Lactones in Asteraceae Plant Extracts: Evaluation of their Allergenic Potential.

    Science.gov (United States)

    Salapovic, Helena; Geier, Johannes; Reznicek, Gottfried

    2013-01-01

    Sesquiterpene lactones (SLs), mainly those with an activated exocyclic methylene group, are important allergens in Asteraceae (Compositae) plants. As a screening tool, the Compositae mix, consisting of five Asteraceae plant extracts with allergenic potential (feverfew, tansy, arnica, yarrow, and German chamomile) is part of several national patch test baseline series. However, the SL content of the Compositae mix may vary due to the source material. Therefore, a simple spectrophotometric method for the quantitative measurement of SLs with the α-methylene-γ-butyrolactone moiety was developed, giving the percentage of allergenic compounds in plant extracts. The method has been validated and five Asteraceae extracts, namely feverfew (Tanacetum parthenium L.), tansy (Tanacetum vulgare L.), arnica (Arnica montana L.), yarrow (Achillea millefolium L.), and German chamomile (Chamomilla recutita L. Rauschert) that have been used in routine patch test screening were evaluated. A good correlation could be found between the results obtained using the proposed spectrophotometric method and the corresponding clinical results. Thus, the introduced method is a valuable tool for evaluating the allergenic potential and for the simple and efficient quality control of plant extracts with allergenic potential.

  14. Developmental and Environmental Effects on Sesquiterpene Lactones in Cultivated Arnica montana L.

    Science.gov (United States)

    Todorova, Milka; Trendafilova, Antoaneta; Vitkova, Antonina; Petrova, Maria; Zayova, Ely; Antonova, Daniela

    2016-08-01

    The amount of sesquiterpene lactones and the lactone profile of Arnica montana L. in flowering and seed formation stages in vitro and in vivo propagated from seeds of German, Ukrainian, and Austrian origin and grown in two experimental fields were studied. It was found that in vitro propagated 2-year plants in full flowering stage accumulated higher amount of lactones in comparison to in vivo propagated 3-year plants and to the seed formation stage, respectively. Helenalins predominated in in vivo propagated 2-year or in vitro propagated 3-year plants. 2-Methylbutyrate (2MeBu) was the principal ester in the samples with prevalence of helenalins, while isobutyrate (iBu) was the major one in the samples with predominance of 11,13-dihydrohelenalins. The results revealed that the environmental conditions on Vitosha Mt. are more suitable for cultivation of A. montana giving higher content of lactones.

  15. Role of needle surface waxes in dynamic exchange of mono- and sesquiterpenes

    Science.gov (United States)

    Joensuu, Johanna; Altimir, Nuria; Hakola, Hannele; Rostás, Michael; Raivonen, Maarit; Vestenius, Mika; Aaltonen, Hermanni; Riederer, Markus; Bäck, Jaana

    2016-06-01

    Biogenic volatile organic compounds (BVOCs) produced by plants have a major role in atmospheric chemistry. The different physicochemical properties of BVOCs affect their transport within and out of the plant as well as their reactions along the way. Some of these compounds may accumulate in or on the waxy surface layer of conifer needles and participate in chemical reactions on or near the foliage surface. The aim of this work was to determine whether terpenes, a key category of BVOCs produced by trees, can be found on the epicuticles of Scots pine (Pinus sylvestris L.) and, if so, how they compare with the terpenes found in shoot emissions of the same tree. We measured shoot-level emissions of pine seedlings at a remote outdoor location in central Finland and subsequently analysed the needle surface waxes for the same compounds. Both emissions and wax extracts were clearly dominated by monoterpenes, but the proportion of sesquiterpenes was higher in the wax extracts. There were also differences in the terpene spectra of the emissions and the wax extracts. The results, therefore, support the existence of BVOC associated to the epicuticular waxes. We briefly discuss the different pathways for terpenes to reach the needle surfaces and the implications for air chemistry.

  16. Fate of PBDEs during food processing: Assessment of formation of mixed chlorinated/brominated diphenyl ethers and brominated dioxins/furans.

    Science.gov (United States)

    Roszko, Marek; Szymczyk, Krystyna; Jędrzejczak, Renata

    2015-01-01

    The aim of this study was to evaluate effects of food processing on PBDE levels, in particular influence of heat treatment on degradation of PBDEs, including possible formation of chlorinated diphenyl ethers or brominated dioxins/furans as degradation products. It was shown that PBDEs heated in the presence of chlorine (from either organic or inorganic sources) formed mixed chlorinated/brominated diphenyl ethers. However, no PCDEs were formed in the presence of lipids. Lipid medium increased stability of PBDEs exposed to UV irradiation. Profile of congeners formed in result of the debromination reaction was significantly different than profiles observed by some other authors in aliphatic organic solvents. Grilling processes increased concentrations (calculated on the fresh product basis) of the studied compounds by 4-8/22-34% for electric/coal grill, respectively. Depending on the congener and on the applied heat treatment, PBDE mass in pork meat after grilling dropped by 26-53%. No detectable quantities of either brominated dioxins or furans were formed during thermal processing of food containing typical levels of PBDEs.

  17. In-situ ambient quantification of monoterpenes, sesquiterpenes, and related oxygenated compounds during BEARPEX 2007 – implications for gas- and particle-phase chemistry

    Directory of Open Access Journals (Sweden)

    N. C. Bouvier-Brown

    2009-04-01

    Full Text Available We quantified ambient mixing ratios of 9 monoterpenes, 6 sesquiterpenes, methyl chavicol, the oxygenated terpene linalool, and nopinone using an in-situ gas chromatograph with a quadrupole mass spectrometer (GC-MS. These measurements were a part of the 2007 Biosphere Effects on AeRosols and Photochemistry EXperiment (BEARPEX at Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. To our knowledge, these observations represent the first direct in-situ ambient quantification of the sesquiterpenes α-bergamotene, longifolene, α-farnesene, and β-farnesene. From average diurnal mixing ratio profiles, we show that α-farnesene emissions are dependent mainly on temperature whereas α-bergamotene and β-farnesene emissions are temperature- and light-dependent. The amount of sesquiterpene mass quantified above the canopy was small (averaging a total of 3.3 ppt during the day, but nevertheless these compounds contributed 8.5% to the overall ozone reactivity above the canopy. Assuming that the monoterpene-to-sesquiterpene emission rate in the canopy is similar to that observed in branch enclosure studies at the site during comparable weather conditions, and the average yield of aerosol mass from these sesquiterpenes is 10–50%, the amount of sesquiterpene mass reacted within the Blodgett Forest canopy alone accounts for 8–38% of the total organic aerosol mass measured during BEARPEX. The oxygenated monoterpene linalool was also quantified for the first time at Blodgett Forest. The linalool mass contribution was small (9.9 ppt and 0.74 ppt within and above the canopy, respectively, but it contributed 1.2% to the total ozone reactivity above the canopy. Reactive and semi-volatile compounds, especially sesquiterpenes, significantly impact the gas- and particle-phase chemistry of the atmosphere at Blodgett Forest and should be included in both biogenic volatile organic carbon emission and atmospheric chemistry models.

  18. In-situ ambient quantification of monoterpenes, sesquiterpenes, and related oxygenated compounds during BEARPEX 2007: implications for gas- and particle-phase chemistry

    Directory of Open Access Journals (Sweden)

    N. C. Bouvier-Brown

    2009-08-01

    Full Text Available We quantified ambient mixing ratios of 9 monoterpenes, 6 sesquiterpenes, methyl chavicol, the oxygenated terpene linalool, and nopinone using an in-situ gas chromatograph with a quadrupole mass spectrometer (GC-MS. These measurements were a part of the 2007 Biosphere Effects on AeRosols and Photochemistry EXperiment (BEARPEX at Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. To our knowledge, these observations represent the first direct in-situ ambient quantification of the sesquiterpenes α-bergamotene, longifolene, α-farnesene, and β-farnesene. From average diurnal mixing ratio profiles, we show that α-farnesene emissions are dependent mainly on temperature whereas α-bergamotene and β-farnesene emissions are temperature- and light-dependent. The amount of sesquiterpene mass quantified above the canopy was small (averaging a total of 3.3 ppt during the day, but nevertheless these compounds contributed 7.6% to the overall ozone-olefin loss rate above the canopy. Assuming that the monoterpene-to-sesquiterpene emission rate in the canopy is similar to that observed in branch enclosure studies at the site during comparable weather conditions, and the average yield of aerosol mass from these sesquiterpenes is 10–50%, the amount of sesquiterpene mass reacted within the Blodgett Forest canopy alone accounts for 6–32% of the total organic aerosol mass measured during BEARPEX. The oxygenated monoterpene linalool was also quantified for the first time at Blodgett Forest. The linalool mass contribution was small (9.9 ppt and 0.74 ppt within and above the canopy, respectively, but it contributed 1.1% to the total ozone-olefin loss rate above the canopy. Reactive and semi-volatile compounds, especially sesquiterpenes, significantly impact the gas- and particle-phase chemistry of the atmosphere at Blodgett Forest and should be included in both biogenic volatile organic carbon emission and atmospheric chemistry

  19. Regioselective chlorination and bromination of unprotected anilines under mild conditions using copper halides in ionic liquids

    Directory of Open Access Journals (Sweden)

    Han Wang

    2012-05-01

    Full Text Available By using ionic liquids as solvents, the chlorination or bromination of unprotected anilines at the para-position can be achieved in high yields with copper halides under mild conditions, without the need for potentially hazardous operations such as supplementing oxygen or gaseous HCl.

  20. 二溴海因溴化邻苯二酚%Bromination of Catechol Using Dibromohydantoin

    Institute of Scientific and Technical Information of China (English)

    王宁宁; 鲍猛; 牟宗刚; 王慧; 刘传仁

    2011-01-01

    4, 5 -Dibromocateehol were synthesised by using dibromohydantoin as brominating agent to react with the eatechol, in glacial acetic acid environment, in ice - water bath. The method overcame the shortcomings of the traditional method using liquid bromine as the brominating agent and effectively improved the yield. By studing the molar ratio of brominated agent and raw materials, the reaction time and the reaction temperature, the experiment determined that the optimal molar ratio was 2:1, each appropriate feeding time interval was 20 minutes, and the optimum reaction temperature was -5 -0 ℃.%在冰醋酸环境下,在冰水浴中,用二溴海因作为溴化剂,与邻苯二酚反应合成4,5-二溴邻苯二酚。该方法克服传统方法中用液溴作为溴化剂的缺点并有效地提高了产率。该实验通过对溴化剂与原料的物质的量比、反应时间以及反应温度的研究,确定最佳物质的量比是2:1,每次加料时间间隔为20min为宜、反应最佳温度为-5-O℃。

  1. In vitro profiling of the endocrine-disrupting potency of brominated flame retardants

    NARCIS (Netherlands)

    Hamers, T.H.M.; Kamstra, J.H.; Sonneveld, E.; Murk, A.J.; Kester, M.H.A.; Andersson, P.L.; Legler, J.; Brouwer, A.

    2006-01-01

    Over the last years, increasing evidence has become available that some brominated flame retardants (BFRs) may have endocrine disrupting (ED) potencies. The goal of the current study was to perform a systematic in vitro screening of the ED potencies of BFRs (1) to elucidate possible modes of action

  2. Molecular characterization of brominated persistent pollutants using extended X-ray absorption fine structure (EXAFS) spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bergknut, Magnus; Skyllberg, Ulf [Swedish University of Agricultural Sciences (SLU), Department of Forest Ecology and Management, Umeaa (Sweden); Persson, Per [Umeaa University, Department of Chemistry, Umeaa (Sweden)

    2008-02-15

    X-ray absorption fine structure (EXAFS) spectroscopy spectra were collected for three brominated persistent pollutants: 6-bromo-2,4,5-trichlorophenol (BrTriClP), pentabromophenol (PentaBrP) and 3,3',5,5'-tetrabromobisphenol A (TBBA). The substances were selected to be symmetrical (BrTriClP and TBBA) or asymmetrical (PentaBrP) with respect to the atomic Br positions and to differ in the number of bromine and other halide atoms, as well as their relative positions. The asymmetrical PentaBrP was modelled with special detail as not all bromine atoms have identical coordination environments. The studied substances displayed unique EXAFS spectra, which could be used to determine the molecular structure in fair detail. We conclude that EXAFS spectroscopy is a suitable technique for molecular characterization of the comparatively complex molecules within the class of compounds of brominated organic persistent pollutants. A detailed understanding of the EXAFS spectra of the pure compounds opens up possibilities to study the interactions with soil and sediment matrices by means of EXAFS spectroscopy. (orig.)

  3. Kinetics of aerobic cometabolic biodegradation of chlorinated and brominated aliphatic hydrocarbons: A review.

    Science.gov (United States)

    Jesus, João; Frascari, Dario; Pozdniakova, Tatiana; Danko, Anthony S

    2016-05-15

    This review analyses kinetic studies of aerobic cometabolism (AC) of halogenated aliphatic hydrocarbons (HAHs) from 2001-2015 in order to (i) compare the different kinetic models proposed, (ii) analyse the estimated model parameters with a focus on novel HAHs and the identification of general trends, and (iii) identify further research needs. The results of this analysis show that aerobic cometabolism can degrade a wide range of HAHs, including HAHs that were not previously tested such as chlorinated propanes, highly chlorinated ethanes and brominated methanes and ethanes. The degree of chlorine mineralization was very high for the chlorinated HAHs. Bromine mineralization was not determined for studies with brominated aliphatics. The examined research period led to the identification of novel growth substrates of potentially high interest. Decreasing performance of aerobic cometabolism were found with increasing chlorination, indicating the high potential of aerobic cometabolism in the presence of medium- and low-halogenated HAHs. Further research is needed for the AC of brominated aliphatic hydrocarbons, the potential for biofilm aerobic cometabolism processes, HAH-HAH mutual inhibition and the identification of the enzymes responsible for each aerobic cometabolism process. Lastly, some indications for a possible standardization of future kinetic studies of HAH aerobic cometabolism are provided.

  4. Deposition history of brominated flame retardant compounds in an ice core from Holtedahlfonna, Svalbard, Norway

    NARCIS (Netherlands)

    Hermanson, M.H.; Isaksson, E.; Forsström, S.; Teixeira, C.; Muir, D.C.G.; Pohjola, V.A.; van de Wal, R.S.W.

    2010-01-01

    Brominated flame retardants (BFRs) have been found in Arctic wildlife, lake sediment, and air. To identify the atmospheric BFR deposition history on Svalbard, Norway, we analyzed 19 BFRs, including hexabromocyclododecane (HBCD), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane

  5. Canadian Arctic sea ice reconstructed from bromine in the Greenland NEEM ice core

    Science.gov (United States)

    Spolaor, Andrea; Vallelonga, Paul; Turetta, Clara; Maffezzoli, Niccolò; Cozzi, Giulio; Gabrieli, Jacopo; Barbante, Carlo; Goto-Azuma, Kumiko; Saiz-Lopez, Alfonso; Cuevas, Carlos A.; Dahl-Jensen, Dorthe

    2016-09-01

    Reconstructing the past variability of Arctic sea ice provides an essential context for recent multi-year sea ice decline, although few quantitative reconstructions cover the Holocene period prior to the earliest historical records 1,200 years ago. Photochemical recycling of bromine is observed over first-year, or seasonal, sea ice in so-called “bromine explosions” and we employ a 1-D chemistry transport model to quantify processes of bromine enrichment over first-year sea ice and depositional transport over multi-year sea ice and land ice. We report bromine enrichment in the Northwest Greenland Eemian NEEM ice core since the end of the Eemian interglacial 120,000 years ago, finding the maximum extension of first-year sea ice occurred approximately 9,000 years ago during the Holocene climate optimum, when Greenland temperatures were 2 to 3 °C above present values. First-year sea ice extent was lowest during the glacial stadials suggesting complete coverage of the Arctic Ocean by multi-year sea ice. These findings demonstrate a clear relationship between temperature and first-year sea ice extent in the Arctic and suggest multi-year sea ice will continue to decline as polar amplification drives Arctic temperatures beyond the 2 °C global average warming target of the recent COP21 Paris climate agreement.

  6. Canadian Arctic sea ice reconstructed from bromine in the Greenland NEEM ice core.

    Science.gov (United States)

    Spolaor, Andrea; Vallelonga, Paul; Turetta, Clara; Maffezzoli, Niccolò; Cozzi, Giulio; Gabrieli, Jacopo; Barbante, Carlo; Goto-Azuma, Kumiko; Saiz-Lopez, Alfonso; Cuevas, Carlos A; Dahl-Jensen, Dorthe

    2016-09-21

    Reconstructing the past variability of Arctic sea ice provides an essential context for recent multi-year sea ice decline, although few quantitative reconstructions cover the Holocene period prior to the earliest historical records 1,200 years ago. Photochemical recycling of bromine is observed over first-year, or seasonal, sea ice in so-called "bromine explosions" and we employ a 1-D chemistry transport model to quantify processes of bromine enrichment over first-year sea ice and depositional transport over multi-year sea ice and land ice. We report bromine enrichment in the Northwest Greenland Eemian NEEM ice core since the end of the Eemian interglacial 120,000 years ago, finding the maximum extension of first-year sea ice occurred approximately 9,000 years ago during the Holocene climate optimum, when Greenland temperatures were 2 to 3 °C above present values. First-year sea ice extent was lowest during the glacial stadials suggesting complete coverage of the Arctic Ocean by multi-year sea ice. These findings demonstrate a clear relationship between temperature and first-year sea ice extent in the Arctic and suggest multi-year sea ice will continue to decline as polar amplification drives Arctic temperatures beyond the 2 °C global average warming target of the recent COP21 Paris climate agreement.

  7. Unintentional production of persistent chlorinated and brominated organic pollutants during iron ore sintering processes.

    Science.gov (United States)

    Li, Sumei; Liu, Guorui; Zheng, Minghui; Liu, Wenbin; Li, Jinhui; Wang, Mei; Li, Changliang; Chen, Yuan

    2017-06-05

    Iron ore sintering (SNT) processes are major sources of unintentionally produced chlorinated persistent organic pollutants (POPs), including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). However, few studies of emissions of brominated POPs, such as polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) and polybrominated diphenyl ethers (PBDEs), during SNT have been performed. Stack gas and fly ash samples from six typical SNT plants in China were collected and analyzed to determine the concentrations and profiles of PCDD/Fs, PCBs, PCNs, PBDD/Fs, and PBDEs, as well as any correlations among these compounds. The PCDD/F, PCB, PCN, PBDD/F, and PBDE emission factors were 2.47, 0.61, 552, 0.32, and 107μgt(-1), respectively (109, 4.07, 10.4, 4.41 and 0.02ng toxic equivalents t(-1), respectively). PCBs were the most abundant compounds by mass, while PCNs were the next most abundant, contributing 51% and 42% to the total POP concentration, respectively. However, PCDD/Fs were the dominant contributors to the chlorinated and brominated POP toxic equivalent concentrations, contributing 89% to the total toxic equivalent concentration. The PCDD/F and other chlorinated and brominated POP concentrations were positively correlated, indicating that chlorinated and brominated POP emissions could be synergistically decreased using the best available technologies/best environmental practices already developed for PCDD/Fs.

  8. Performance and Degradation of A Lithium-Bromine Rechargeable Fuel Cell Using Highly Concentrated Catholytes

    CERN Document Server

    Bai, Peng

    2016-01-01

    Lithium-air batteries have been considered as ultimate solutions for the power source of long-range electrified transportation, but state-of-the-art prototypes still suffer from short cycle life, low efficiency and poor power output. Here, a lithium-bromine rechargeable fuel cell using highly concentrated bromine catholytes is demonstrated with comparable specific energy, improved power density, and higher efficiency. The cell is similar in structure to a hybrid-electrolyte Li-air battery, where a lithium metal anode in nonaqueous electrolyte is separated from aqueous bromine catholytes by a lithium-ion conducting ceramic plate. The cell with a flat graphite electrode can discharge at a peak power density around 9mW cm-2 and in principle could provide a specific energy of 791.8 Wh kg-1, superior to most existing cathode materials and catholytes. It can also run in regenerative mode to recover the lithium metal anode and free bromine with 80-90% voltage efficiency, without any catalysts. Degradation of the sol...

  9. Using the parallelogram approach to estimate human percutaneous bioavailability for novel & legacy brominated flame retardants

    Science.gov (United States)

    (This is an extended abstract. The following text was taken from the Discussion and Conclusion section.) Humans are frequently exposed to brominated flame retardants (BFRs), especially via dermal contact with contaminated dust. Human and rat skin data were integrated using a pa...

  10. On the bromination of the dihydroazulene/vinylheptafulvene photo-/thermoswitch

    DEFF Research Database (Denmark)

    Mazzanti, Virginia; Cacciarini, M.; Broman, Søren Lindbæk;

    2012-01-01

    as of the known 7-bromo-DHA. Results: Radical bromination on two different VHFs by using N-bromosuccinimide/benzoyl peroxide and light, followed by a ring-closure reaction generated the corresponding 3-bromo-DHAs, as confirmed in one case by X-ray crystallography. According to a H-1 NMR spectroscopic study...

  11. Canadian Arctic sea ice reconstructed from bromine in the Greenland NEEM ice core

    Science.gov (United States)

    Spolaor, Andrea; Vallelonga, Paul; Turetta, Clara; Maffezzoli, Niccolò; Cozzi, Giulio; Gabrieli, Jacopo; Barbante, Carlo; Goto-Azuma, Kumiko; Saiz-Lopez, Alfonso; Cuevas, Carlos A.; Dahl-Jensen, Dorthe

    2016-01-01

    Reconstructing the past variability of Arctic sea ice provides an essential context for recent multi-year sea ice decline, although few quantitative reconstructions cover the Holocene period prior to the earliest historical records 1,200 years ago. Photochemical recycling of bromine is observed over first-year, or seasonal, sea ice in so-called “bromine explosions” and we employ a 1-D chemistry transport model to quantify processes of bromine enrichment over first-year sea ice and depositional transport over multi-year sea ice and land ice. We report bromine enrichment in the Northwest Greenland Eemian NEEM ice core since the end of the Eemian interglacial 120,000 years ago, finding the maximum extension of first-year sea ice occurred approximately 9,000 years ago during the Holocene climate optimum, when Greenland temperatures were 2 to 3 °C above present values. First-year sea ice extent was lowest during the glacial stadials suggesting complete coverage of the Arctic Ocean by multi-year sea ice. These findings demonstrate a clear relationship between temperature and first-year sea ice extent in the Arctic and suggest multi-year sea ice will continue to decline as polar amplification drives Arctic temperatures beyond the 2 °C global average warming target of the recent COP21 Paris climate agreement. PMID:27650478

  12. Exposure assessment of Dutch nursing infants to brominated flame retardants via breast milk

    NARCIS (Netherlands)

    Winter-Sorkina R de; Bakker MI; Baumann RA; Hoogerbrugge R; Zeilmaker MJ; SIR

    2004-01-01

    As part of a national survey on the occurrence of persistent organic contaminants in breast milk, a group of brominated flame retardants (polybrominated diphenyl ethers or PBDEs) was measured in breast milk which had been collected in 1998 from Dutch primiparous women on day 6 to 10 after labour. To

  13. Toxicity of brominated flame retardants in fish, with emphasis on endocrine effects and reproduction

    NARCIS (Netherlands)

    Kuiper, R.V.

    2007-01-01

    Abstract The abundant use of brominated flame retardants (BFRs) in modern polymers has over the passed decades resulted in contamination of the environment, and BFRs are increasingly found in fish. Laboratory studies have shown that a number of BFRs and BFR-metabolites can interfere with thyroid and

  14. Brominated Flame Retardants and their metabolites: Novel insights into endocrine disruptive properties.

    NARCIS (Netherlands)

    Fernández Cantón, R.

    2008-01-01

    Brominated flame retardants (BFRs) are chemicals that are added to materials to inhibit or suppress ignition and are incorporated during the manufacture of e.g. electronic equipment, furniture, construction materials and textiles. BFRs have become an increasingly important group of organohalogen com

  15. Brominated flame retardants and the formation of dioxins and furans in fires and combustion.

    Science.gov (United States)

    Zhang, Mengmei; Buekens, Alfons; Li, Xiaodong

    2016-03-05

    The widespread use and increasing inventory of brominated flame retardants (BFRs) have caused considerable concern, as a result of BFRs emissions to the environment and of the formation of both polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and mixed polybromochloro-dibenzo-p-dioxins and dibenzofurans (PBCDD/Fs or PXDD/Fs). Structural similarities between PBDD/Fs and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) suggest the existence of comparable formation pathways of both PBDD/Fs and PCDD/Fs, yet BFRs also act as specific precursors to form additional PBDD/Fs. Moreover, elementary bromine (Br2) seems to facilitate chlorination by bromination of organics, followed by Br/Cl-exchange based on displacement through the more reactive halogen. Overall, PBDD/Fs form through three possible pathways: precursor formation, de novo formation, and dispersion of parts containing BFRs as impurities and surviving a fire or other events. The present review summarises the formation mechanisms of both brominated (PBDD/Fs) and mixed dioxins (PXDD/Fs with X=Br or Cl) from BFRs, recaps available emissions data of PBDD/Fs and mixed PXDD/Fs from controlled waste incineration, uncontrolled combustion sources and accidental fires, and identifies and analyses the effects of several local factors of influence, affecting the formation of PBDD/Fs and mixed PXDD/Fs during BFRs combustion.

  16. Thermoelectric properties of bromine filled CoSb3 skutterudite

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz, Brenden R.; Crawford, Caitlin M.; McKinney, Robert W.; Parilla, Philip A.; Toberer, Eric S.

    2016-01-01

    Historically, the improved thermoelectric performance of skutterudite compounds has largely been driven by the incorporation of electropositive donors on interstitial sites. These 'rattlers' serve to optimize both electronic and thermal properties by tuning the carrier concentration and scattering phonons. In this work, we show that interstitial bromine can be incorporated into CoSb3 and assess the impact on electronic and thermal transport. In contrast to prior high pressure syntheses with iodine, interstitial bromine incorporation is achieved at ambient pressure. Transport properties are stable up to at least 375 degrees C. Bromine serves as an electronegative acceptor and can induce degenerate (>5 x 1019 cm-3) hole densities. In contrast to other p-type skutterudite compositions, bromine preserves the intrinsically high hole mobility of CoSb3 while significantly reducing the lattice thermal conductivity. The development of a stable p-type dopant for the interstitial filler site enables the development of skutterudites with both donor and acceptor interstitials to maximize phonon scattering while maintaining the high mobility of CoSb3.

  17. The Effects of Bromination Methods on the Microstructure of Brominated Natural Rubbers from Latex%溴化方式对胶乳法溴化天然橡胶结构的影响

    Institute of Scientific and Technical Information of China (English)

    赵法敏; 薛行华; 张子琦; 张利伟; 李光

    2013-01-01

    为改善溴化天然橡胶(BNR)的溶解性能,在胶乳法的基础上改变溴化方式,以常规溴化方式和分步溴化方式分别制备了BNR.通过实验发现,体系溴浓度相同时分步溴化方式的溴含量比常规溴化方式高,而凝胶含量较低,所以分步溴化方式在甲苯中的溶解性能较好.通过傅里叶红外光谱对样品进行表征,并使用核磁共振对其微观结构进行了定性定量分析.红外光谱分析表明,2种溴化方式制备的BNR产物均发生了一定程度的溴加成反应和溴取代反应;核磁共振的分析证实了在体系溴浓度较低的情况下,与胶乳法常规溴化相反,胶乳法分步溴化的溴化过程主要以溴加成反应为主,少量发生溴取代反应.%In order to improve the solubility property of the brominated natural rubbers (BNR)from latex, BNR were prepared by changing the bromination ways from conventional bromination to step bromination. Through the experiment, it was discovered that the bromine content of the latter was higher than the former, but the gel content was less under the same bromine concentration. The latter showed much better solubility in the solvent of toluene. The structure of the procured sample was characterized by Fourier transform infrared spectroscopy (FTIR), and the microstructures of brominated nature rubber were qualitatively and quantitatively analyzed by nuclear magnetic resonance (NMR). FTIR showed that there were both a degree of brominated addition reaction and brominated substitution reaction in the obtained BNR by two different methods; Contrary to the conventional bromination from latex, the analysis of NMR proved that the bromination process of step bromination from latex was mainly in the form of addition reaction, and only a small amount of the substitution reaction did occur.

  18. Distribution of copper, silver and gold during thermal treatment with brominated flame retardants

    Energy Technology Data Exchange (ETDEWEB)

    Oleszek, Sylwia, E-mail: sylwia_oleszek@yahoo.com [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan); Institute of Environmental Engineering of the Polish Academy of Sciences, 34 M. Sklodowska-Curie St., 41-819 Zabrze (Poland); Grabda, Mariusz, E-mail: mariusz@mail.tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan); Institute of Environmental Engineering of the Polish Academy of Sciences, 34 M. Sklodowska-Curie St., 41-819 Zabrze (Poland); Shibata, Etsuro, E-mail: etsuro@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan); Nakamura, Takashi, E-mail: ntakashi@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, 1,1 Katahira, 2-Chome, Sendai 980-8577 (Japan)

    2013-09-15

    Highlights: • Copper, silver and gold during thermal treatment with brominated flame retardants. • Distribution of copper, silver and gold during thermal processing. • Thermodynamic considerations of the bromination reactions. - Abstract: The growing consumption of electric and electronic equipment results in creating an increasing amount of electronic waste. The most economically and environmentally advantageous methods for the treatment and recycling of waste electric and electronic equipment (WEEE) are the thermal techniques such as direct combustion, co-combustion with plastic wastes, pyrolysis and gasification. Nowadays, this kind of waste is mainly thermally treated in incinerators (e.g. rotary kilns) to decompose the plastics present, and to concentrate metals in bottom ash. The concentrated metals (e.g. copper, precious metals) can be supplied as a secondary raw material to metal smelters, while the pyrolysis of plastics allows the recovery of fuel gases, volatilising agents and, eventually, energy. Indeed, WEEE, such as a printed circuit boards (PCBs) usually contains brominated flame retardants (BFRs). From these materials, hydrobromic acid (HBr) is formed as a product of their thermal decomposition. In the present work, the bromination was studied of copper, silver and gold by HBr, originating from BFRs, such as Tetrabromobisphenol A (TBBPA) and Tetrabromobisphenol A-Tetrabromobisophenol A diglycidyl ether (TTDE) polymer; possible volatilization of the bromides formed was monitored using a thermo-gravimetric analyzer (TGA) and a laboratory-scale furnace for treating samples of metals and BFRs under an inert atmosphere and at a wide range of temperatures. The results obtained indicate that up to about 50% of copper and silver can evolve from sample residues in the form of volatile CuBr and AgBr above 600 and 1000 °C, respectively. The reactions occur in the molten resin phase simultaneously with the decomposition of the brominated resin. Gold is

  19. Interactions of bromine, chlorine, and iodine photochemistry during ozone depletions in Barrow, Alaska

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    C. R. Thompson

    2014-11-01

    Full Text Available The springtime depletion of tropospheric ozone in the Arctic is known to be caused by active halogen photochemistry resulting from halogen atom precursors emitted from snow, ice, or aerosol surfaces. The role of bromine in driving ozone depletion events (ODEs has been generally accepted, but much less is known about the role of chlorine radicals in ozone depletion chemistry. While the potential impact of iodine in the High Arctic is more uncertain, there have been indications of active iodine chemistry through observed enhancements in filterable iodide, probable detection of tropospheric IO, and recently, detection of atmospheric I2. Despite decades of research, significant uncertainty remains regarding the chemical mechanisms associated with the bromine-catalyzed depletion of ozone, as well as the complex interactions that occur in the polar boundary layer due to halogen chemistry. To investigate this, we developed a zero-dimensional photochemical model, constrained with measurements from the 2009 OASIS field campaign in Barrow, Alaska. We simulated a 7 day period during late March that included a full ozone depletion event lasting 3 days and subsequent ozone recovery to study the interactions of halogen radicals under these different conditions. In addition, the effects of iodine added to our base model were investigated. While bromine atoms were primarily responsible for ODEs, chlorine and iodine were found to enhance the depletion rates and iodine was found to be more efficient per atom at depleting ozone than Br. The interaction between chlorine and bromine is complex, as the presence of chlorine can increase the recycling and production of Br atoms, while also increasing reactive bromine sinks under certain conditions. Chlorine chemistry was also found to have significant impacts on both HO2 and RO2. The results of this work highlight the need for future studies on the production mechanisms of Br2 and Cl2, as well as on the potential

  20. Monitoring of WEEE plastics in regards to brominated flame retardants using handheld XRF

    Energy Technology Data Exchange (ETDEWEB)

    Aldrian, Alexia, E-mail: alexia.aldrian@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria); Ledersteger, Alfred, E-mail: a.ledersteger@saubermacher.at [Saubermacher Dienstleistungs AG, Hans-Roth-Straße 1, 8073 Feldkirchen bei Graz (Austria); Pomberger, Roland, E-mail: roland.pomberger@unileoben.ac.at [Chair of Waste Processing Technology and Waste Management, Montanuniversitaet Leoben, Franz-Josef-Straße 18, 8700 Leoben (Austria)

    2015-02-15

    Highlights: • Specification of an empirical factor for conversion from bromine to PBB and PBDE. • The handheld XRF device was validated for this particular application. • A very large number of over 4600 pieces of monitor housings was analysed. • The recyclable fraction mounts up to 85% for TV but only 53% of PC waste plastics. • A high percentage of pieces with bromine contents of over 50,000 ppm was obtained. - Abstract: This contribution is focused on the on-site determination of the bromine content in waste electrical and electronic equipment (WEEE), in particular waste plastics from television sets (TV) and personal computer monitors (PC) using a handheld X-ray fluorescence (XRF) device. The described approach allows the examination of samples in regards to the compliance with legal specifications for polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) directly after disassembling and facilitates the sorting out of plastics with high contents of brominated flame retardants (BFRs). In all, over 3000 pieces of black (TV) and 1600 pieces of grey (PC) plastic waste were analysed with handheld XRF technique for this study. Especially noticeable was the high percentage of pieces with a bromine content of over 50,000 ppm for TV (7%) and PC (39%) waste plastics. The applied method was validated by comparing the data of handheld XRF with results obtained by GC–MS. The results showed the expected and sufficiently accurate correlation between these two methods. It is shown that handheld XRF technique is an effective tool for fast monitoring of large volumes of WEEE plastics in regards to BFRs for on-site measurements.

  1. Determination of iodine and bromine compounds in foodstuffs by CE-inductively coupled plasma MS.

    Science.gov (United States)

    Chen, Jing-Huan; Wang, Kai-en; Jiang, Shiuh-Jen

    2007-11-01

    A CE-inductively coupled plasma mass spectrometric (CE-ICP-MS) method for iodine and bromine speciation analysis is described. Samples containing ionic iodine (I(-) and IO(3)(-)) and bromine (Br(-) and BrO(3)(-)) species are subjected to electrophoretic separation before injection into the microconcentric nebulizer (CEI-100). The separation has been achieved in a 50 cm length x 75 microm id fused-silica capillary. The electrophoretic buffer used is 10 mmol/L Tris (pH 8.0), while the applied voltage is set at -8 kV. Detection limits are 1 and 20-50 ng/mL for various I and Br compounds, respectively, based on peak height. The RSD of the peak areas for seven injections of 0.1 microg/mL I(-), IO(3)(-) and 1 microg/mL Br(-), BrO(3)(-) mixture is in the range of 3-5%. This method has been applied to determine various iodine and bromine species in NIST SRM 1573a Tomato Leaves reference material and a salt and seaweed samples obtained locally. A microwave-assisted extraction method is used for the extraction of these compounds. Over 87% of the total iodine and 83% of the total bromine are extracted using a 10% m/v tetramethylammonium hydroxide (TMAH) solution in a focused microwave field within a period of 10 min. The spike recoveries are in the range of 94-105% for all the determinations. The major species of iodine and bromine in tomato leaves, salt, and seaweed are Br(-), IO(3)(-), I(-), and Br(-), respectively.

  2. Iodine and bromine speciation in snow and the effect of orographically induced precipitation

    Directory of Open Access Journals (Sweden)

    H. Biester

    2007-05-01

    Full Text Available Iodine is an essential trace element for all mammals and may also influence climate through new aerosol formation. Atmospheric bromine cycling is also important due to its well-known ozone depletion capabilities. Despite precipitation being the ultimate source of iodine in the terrestrial environment, the processes effecting its distribution, speciation and transport are relatively unknown. The aim of this study was to determine the effect of orographically induced precipitation on iodine concentrations in snow and also to quantify the inorganic and organic iodine and bromine species. Snow samples were collected over an altitude profile (~840 m from the northern Black Forest and were analysed by ion-chromatography - inductively coupled plasma mass spectrometry (IC-ICP-MS for iodine and bromine species and trace metals (ICP-MS. All elements and species concentrations in snow showed significant (r2>0.65 exponential decrease relationships with altitude despite the short (5 km horizontal distance of the transect. In fact, total iodine more than halved (38 to 13 nmol/l over the 840 m height change. The results suggest that orographic lifting and subsequent precipitation has a major influence on iodine concentrations in snow. This orographically induced removal effect may be more important than lateral distance from the ocean in determining iodine concentrations in terrestrial precipitation. The microphysical removal process was common to all elements indicating that the iodine and bromine are internally mixed within the snow crystals. We also show that organically bound iodine is the dominant iodine species in snow (61–75%, followed by iodide. Iodate was only found in two samples despite a detection limit of 0.3 nmol/l. Two unknown but most likely anionic organo-I species were also identified in IC-ICP-MS chromatograms and comprised 2–10% of the total iodine. The majority of the bromine was inorganic bromide with a max. of 32% organo-Br.

  3. (+)/(−)-Phaeocaulin A-D, four pairs of new enantiomeric germacrane-type sesquiterpenes from Curcuma phaeocaulis as natural nitric oxide inhibitors

    Science.gov (United States)

    Xia, Gui-yang; Sun, De-juan; Ma, Jiang-hao; Liu, Yue; Zhao, Feng; Owusu Donkor, Paul; Ding, Li-qin; Chen, Li-xia; Qiu, Feng

    2017-01-01

    Germacrane-type sesquiterpenes, with a flexible 10-membered ring unit as the structural and conformational features, play a central role in the biosynthesis and synthesis of other sesquiterpenes. In this report, two pairs of new sesquiterpene alkaloids, (+)/(−)-phaeocaulin A [(+)-1/(−)-1] and B [(+)-2/(−)-2], and two pairs of new sesquiterpenes, (+)/(−)-phaeocaulin C [(+)-3/(−)-3] and D [(+)-4/(−)-4], along with one related known analog (5), were isolated from the rhizomes of Curcuma phaeocaulis. The absolute configurations of (+)-1/(−)-1, (+)-2/(−)-2, (+)-3/(−)-3 and (+)-4/(−)-4 were unambiguously determined by analysis of single-crystal X-ray diffractions and quantum chemical electronic circular dichroism (ECD) method. It is noteworthy that (+)/(−)-phaeocaulin A [(+)-1/(−)-1] and B [(+)-2/(−)-2] are two pairs of rare N-containing germacrane-type sesquiterpenes. A possible biogenetic pathway for 1–5 was postulated. All of the isolated compounds were tested for their inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages. PMID:28272397

  4. The Sesquiterpenes(E-ß-Farnesene and (E-α-Bergamotene Quench Ozone but Fail to Protect the Wild Tobacco Nicotiana attenuata from Ozone, UVB, and Drought Stresses.

    Directory of Open Access Journals (Sweden)

    Evan C Palmer-Young

    Full Text Available Among the terpenes, isoprene (C5 and monoterpene hydrocarbons (C10 have been shown to ameliorate abiotic stress in a number of plant species via two proposed mechanisms: membrane stabilization and direct antioxidant effects. Sesquiterpene hydrocarbons (C15 not only share the structural properties thought to lend protective qualities to isoprene and monoterpene hydrocarbons, but also react rapidly with ozone, suggesting that sesquiterpenes may similarly enhance tolerance of abiotic stresses. To test whether sesquiterpenes protect plants against ozone, UVB light, or drought, we used transgenic lines of the wild tobacco Nicotiana attenuata. The transgenic plants expressed a maize terpene synthase gene (ZmTPS10 which produced a blend of (E-ß-farnesene and (E-α-bergamotene, or a point mutant of the same gene (ZmTPS10M which produced (E-ß-farnesene alone,. (E-ß-farnesene exerted a local, external, and transient ozone-quenching effect in ozone-fumigated chambers, but we found no evidence that enhanced sesquiterpene production by the plant inhibited oxidative damage, or maintained photosynthetic function or plant fitness under acute or chronic stress. Although the sesquiterpenes (E-ß-farnesene and (E-α-bergamotene might confer benefits under intermittent heat stress, which was not tested, any roles in relieving abiotic stress may be secondary to their previously demonstrated functions in biotic interactions.

  5. The effect of bromination of carbon fibers on the coefficient of thermal expansion of graphite fiber-epoxy composites

    Science.gov (United States)

    Jaworske, D. A.; Maciag, C.

    1987-01-01

    To examine the effect of bromination of carbon fibers on the coefficient of thermal expansion (CTE) of carbon fiber epoxy composites, several pristine and brominated carbon fiber-epoxy composite samples were subjected to thermomechanical analysis. The CTE's of these samples were measured in the uniaxial and transverse directions. The CTE was dominated by the fibers in the uniaxial direction, while it was dominated by the matrix in the transverse directions. Bromination had no effect on the CTE of any of the composites. In addition, the CTE of fiber tow was measured in the absence of a polymer matrix, using an extension probe. The results from this technique were inconclusive.

  6. Global atmospheric model for mercury including oxidation by bromine atoms

    Directory of Open Access Journals (Sweden)

    C. D. Holmes

    2010-12-01

    Full Text Available Global models of atmospheric mercury generally assume that gas-phase OH and ozone are the main oxidants converting Hg0 to HgII and thus driving mercury deposition to ecosystems. However, thermodynamic considerations argue against the importance of these reactions. We demonstrate here the viability of atomic bromine (Br as an alternative Hg0 oxidant. We conduct a global 3-D simulation with the GEOS-Chem model assuming gas-phase Br to be the sole Hg0 oxidant (Hg + Br model and compare to the previous version of the model with OH and ozone as the sole oxidants (Hg + OH/O3 model. We specify global 3-D Br concentration fields based on our best understanding of tropospheric and stratospheric Br chemistry. In both the Hg + Br and Hg + OH/O3 models, we add an aqueous photochemical reduction of HgII in cloud to impose a tropospheric lifetime for mercury of 6.5 months against deposition, as needed to reconcile observed total gaseous mercury (TGM concentrations with current estimates of anthropogenic emissions. This added reduction would not be necessary in the Hg + Br model if we adjusted the Br oxidation kinetics downward within their range of uncertainty. We find that the Hg + Br and Hg + OH/O3 models are equally capable of reproducing the spatial distribution of TGM and its seasonal cycle at northern mid-latitudes. The Hg + Br model shows a steeper decline of TGM concentrations from the tropics to southern mid-latitudes. Only the Hg + Br model can reproduce the springtime depletion and summer rebound of TGM observed at polar sites; the snowpack component of GEOS-Chem suggests that 40% of HgII deposited to snow in the Arctic is transferred to the ocean and land reservoirs, amounting to a net deposition flux to the Arctic of 60 Mg a−1. Summertime events of depleted Hg0 at Antarctic sites due to subsidence are much better simulated by

  7. Global atmospheric model for mercury including oxidation by bromine atoms

    Directory of Open Access Journals (Sweden)

    C. D. Holmes

    2010-08-01

    Full Text Available Global models of atmospheric mercury generally assume that OH and ozone are the main oxidants converting Hg0 to HgII and thus driving mercury deposition to ecosystems. However, thermodynamic considerations argue against the importance of these reactions. We demonstrate here the viability of atomic bromine (Br as an alternative Hg0 oxidant. We conduct a global 3-D simulation with the GEOS-Chem model assuming Br to be the sole Hg0 oxidant (Hg + Br model and compare to the previous version of the model with OH and ozone as the sole oxidants (Hg + OH/O3 model. We specify global 3-D Br concentration fields based on our best understanding of tropospheric and stratospheric Br chemistry. In both the Hg + Br and Hg + OH/O3 models, we add an aqueous photochemical reduction of HgII in cloud to impose a tropospheric lifetime for mercury of 6.5 months against deposition, as needed to reconcile observed total gaseous mercury (TGM concentrations with current estimates of anthropogenic emissions. This added reduction would not be necessary in the Hg + Br model if we adjusted the Br oxidation kinetics downward within their range of uncertainty. We find that the Hg + Br and Hg + OH/O3 models are equally capable of reproducing the spatial distribution of TGM and its seasonal cycle at northern mid-latitudes. The Hg + Br model shows a steeper decline of TGM concentrations from the tropics to southern mid-latitudes. Only the Hg + Br model can reproduce the springtime depletion and summer rebound of TGM observed at polar sites; the snowpack component of GEOS-Chem suggests that 40% of HgII deposited to snow in the Arctic is transferred to the ocean and land reservoirs, amounting to a net deposition flux of 60 Mg a−1. Summertime events of depleted Hg0 at Antarctic sites due to subsidence are much better simulated by the Hg + Br model. Model

  8. Antiplasmodial activity of sesquiterpene lactones and a sucrose ester from Vernonia guineensis Benth. (Asteraceae)

    Science.gov (United States)

    Toyang, Ngeh J.; Krause, Michael A.; Fairhurst, Rick M.; Tane, Pierre; Bryant, Joseph; Verpoorte, Rob

    2013-01-01

    Ethnopharmacological relevance Aqueous preparations of Vernonia guineensis Benth. (Asteraceae) are used in Cameroonian folk medicine as a general stimulant and to treat various illnesses and conditions including malaria, bacterial infections and helminthic infestations. Materials and methods 10-g samples of the leaf and tuber powders of V. guineensis were extracted separately using dichloromethane, methanol and distilled water. The extracts were dried in vacuo and used in bioassays. These extracts and three compounds previously isolated from V. guineensis [vernopicrin (1), vernomelitensin (2) and pentaisovalerylsucrose (3)] were screened for antiplasmodial activity against chloroquine (CQ)-sensitive (Hb3) and CQ-resistant (Dd2) Plasmodium falciparum lines. Results Crude extracts and pure compounds from V. guineensis showed antiplasmodial activity against both Hb3 and Dd2. The IC50 values of extracts ranged from 1.64 – 27.2 μg/ml for Hb3 and 1.82 – 30.0 μg/ml for Dd2; those for compounds 1, 2 and 3 ranged from 0.47 – 1.62 μg/ml (1364 – 1774 nM) for Hb3 and 0.57 – 1.50 μg/ml (1644 – 2332 nM) for Dd2. None of the crude extracts or pure compounds was observed to exert toxic effects on the erythrocytes used to cultivate the P. falciparum lines. Conclusion In Cameroonian folk medicine, V. guineensis may be used to treat malaria in part due to the antiplasmodial activity of sesquiterpene lactones (1, 2), a sucrose ester (3) and perhaps other compounds present in crude plant extracts. Exploring the safety and antiplasmodial efficacy of these compounds in vivo requires further study. PMID:23542146

  9. Bioassay-Guided Isolation of Sesquiterpene Coumarins from Ferula narthex Bioss: A New Anticancer Agent

    Science.gov (United States)

    Alam, Mahboob; Khan, Ajmal; Wadood, Abdul; Khan, Ayesha; Bashir, Shumaila; Aman, Akhtar; Jan, Abdul Khaliq; Rauf, Abdur; Ahmad, Bashir; Khan, Abdur Rahman; Farooq, Umar

    2016-01-01

    The main objective of cancer management with chemotherapy (anticancer drugs) is to kill the neoplastic (cancerous) cell instead of a normal healthy cell. The bioassay-guided isolation of two new sesquiterpene coumarins (compounds 1 and 2) have been carried out from Ferula narthex collected from Chitral, locally known as “Raw.” Anticancer activity of crude and all fractions have been carried out to prevent carcinogenesis by using MTT assay. The n-hexane fraction showed good activity with an IC50 value of 5.434 ± 0.249 μg/mL, followed by crude MeFn extract 7.317 ± 0.535 μg/mL, and CHCl3 fraction 9.613 ± 0.548 μg/mL. Compounds 1 and 2 were isolated from chloroform fraction. Among tested pure compounds, compound 1 showed good anticancer activity with IC50 value of 14.074 ± 0.414 μg/mL. PASS (Prediction of Activity Spectra) analysis of the compound 1 was carried out, in order to predicts their binding probability with anti-cancer target. As a results the compound 1 showed binding probability with human histone acetyltransferase with Pa (probability to be active) value of 0.303. The compound 1 was docked against human histone acetyltransferase (anti-cancer drug target) by using molecular docking simulations. Molecular docking results showed that compound 1 accommodate well in the anti-cancer drug target. Moreover the activity support cancer chemo preventive activity of different compounds isolated from the genus Ferula, in accordance with the previously reported anticancer activities of the genus. PMID:26909039

  10. Analytical techniques for sesquiterpene emission rate studies in vegetation enclosure experiments

    Science.gov (United States)

    Helmig, Detlev; Bocquet, Florence; Pollmann, Jan; Revermann, Tobias

    Sesquiterpene (SQT) compounds (C 15H 24) and their oxygenated alcohol and ketone derivatives are biogenic volatile organic compounds that have been identified in emissions from vegetation. SQT emission rates and landscape flux estimates are highly uncertain. Reliable ambient flux measurements have not been possible because of low-ambient concentrations, rapid atmospheric reactions (prohibiting ambient tower flux measurements), and analytical challenges and uncertainties that stem from the low volatility of SQT. Standards from an in situ capillary diffusion system with 18 SQT compounds and four other organic compounds (geranylacetone, 1,3,5-tri-isopropylbenzene, diphenylmethane, nonylbenzene) were used to thoroughly investigate experimental procedures for SQT emission rate studies by vegetation enclosure techniques. Recovery rates in tubing materials, sampling bags, leaf cuvettes, on six solid adsorbent materials (Tenax TA, Tenax GR, Carbotrap, Carbotrap C, Unibeads, Glass Beads) for gas chromatography analysis, and gas chromatography retention indices and mass spectral fragmentation patterns were determined. SQT compounds were found to exhibit a high degree of stickiness to all materials tested. However, the non-oxygenated SQT can be recovered in enclosure experiments for quantitative emission rate determination after careful consideration of the analytical conditions. It is utmost important to allow sufficient purging and equilibration times for all materials in contact with the sample air. In contrast oxygenated SQT were irreversibly lost in enclosure experiments which made their quantitative measurement prohibitive. Results for the other organic compounds were similar and indicate that these data mostly stem from the volatility of these compounds. Consequently, the findings of this study provide guidelines for the analysis of a wide range of volatile organic compounds in the ˜C13-C17 volatility range.

  11. Simultaneous determination of three sesquiterpene lactones in Aucklandia lappa Decne by high performance liquid chromatography

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    Chang-Seob Seo

    2015-01-01

    Full Text Available Background: Aucklandia lappa Decne, a well known traditional herbal medicine, is used for the treatment of asthma, rheumatism, coughs, tuberculosis, and many other diseases. Objective: We performed simultaneous analysis of three sesquiterpene lactones, costunolide (1, dehydrocostus lactone (2, and alantolactone (3, obtained from a 70% methanol extract of A. lappa using high performance liquid chromatography–photodiode array (HPLC–PDA techniques. Materials and Methods: The compounds 1–3 were separated using a reversed phase SunFire™ C18 analytical column kept at 35°C by the isocratic elution with distilled water and acetonitrile as mobile phase. The flow rate was 1.0 mL/min, and the injection volume was 10 μL. Results: The established analytical method showed high linearity, with a correlation coefficient ≥0.9999. The limit of detection and the limit of quantification of compounds 1–3 were 0.06–0.13 μg/mL and 0.21–0.42 μg/mL, respectively. The recovery of the compounds 1–3 was 97.27–103.00%. The intra and inter day relative standard deviations were 0.09–0.97% and 0.09–1.06%, respectively. The amounts of the compounds 1–3 were 17.32, 28.26, and 0.01 mg/g, respectively. Conclusion: The established and validated HPLC–PDA method may be help for the quality control of herbal medicine, A. lappa.

  12. Trypanocidal Activity of Smallanthus sonchifolius: Identification of Active Sesquiterpene Lactones by Bioassay-Guided Fractionation

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    F. M. Frank

    2013-01-01

    Full Text Available In order to find novel plant-derived biologically active compounds against Trypanosoma cruzi, we isolated, from the organic extract of Smallanthus sonchifolius, the sesquiterpene lactones enhydrin (1, uvedalin (2, and polymatin B (3 by bioassay-guided fractionation technique. These compounds showed a significant trypanocidal activity against the epimastigote forms of the parasite with IC50 values of 0.84 μM (1, 1.09 μM (2, and 4.90 μM (3. After a 24 h treatment with 10 μg/mL of enhydrin or uvedalin, parasites were not able to recover their replication rate. Compounds 1 and 2 showed IC50 values of 33.4 μM and 25.0 μM against T. cruzi trypomastigotes, while polymatin B was not active. When the three compounds were tested against the intracellular forms of T. cruzi, they were able to inhibit the amastigote replication with IC50 of 5.17 μM, 3.34 μM, and 9.02 μM for 1, 2, and 3, respectively. The cytotoxicity of the compounds was evaluated in Vero cells obtaining CC50 values of 46.5 μM (1, 46.8 μM (2, and 147.3 μM (3 and the selectivity index calculated. According to these results, enhydrin and uvedalin might have potentials as agents against Chagas disease and could serve as lead molecules to develop new drugs.

  13. Induction of G2/M arrest and apoptosis by sesquiterpene lactones in human melanoma cell lines.

    Science.gov (United States)

    Rozenblat, Sharon; Grossman, Shlomo; Bergman, Margalit; Gottlieb, Hugo; Cohen, Yigal; Dovrat, Sara

    2008-01-15

    Malignant melanoma is a highly aggressive tumor which frequently resists chemotherapy, therefore, the search for new agents for its treatment is of great importance. In this study, we purified the sesquiterpene lactones (SLs), Tomentosin and Inuviscolide from Inula viscosa (Compositae) leaves and studied their anti-cancer potency against human melanoma cell lines in order to develop new agents for melanoma treatment. SLs inhibited the proliferation of three human melanoma cell lines: SK-28, 624 mel and 1363 mel in a dose-dependent manner. We further investigated SLs mechanism of action using SK-28 as a representative cell line model. SLs caused cell-cycle arrest at G(2)/M, accompanied by the appearance of a sub-G0 fraction, indicative of apoptotic cell death. Induction of apoptosis was further confirmed by changes in membrane phospholipids, changes in mitochondrial membrane potential (DeltaPsi) and by detection of Caspase-3 activity. Rapid inhibitory phosphorylation of Cdc2 (Thr14 and Tyr15) was seen early after treatment, followed by a later decrease in the expression level of both Cyclin b1 and Cdc2. Induction of p53 and p21(waf1) proteins and phosphorylation of p53 at Ser15 were also detected early after treatment. The anti-apoptotic proteins, p65 subunit of nuclear factor kappaB (NF-kappaB), and Survivin were reduced in a dose-dependent manner. Taken together, these changes partially explain the ability of the SLs to induce G(2)/M arrest and apoptosis. Induction of apoptosis by Tomentosin and Inuviscolide in human aggressive melanoma cell lines has high pharmacological value and implies that SLs might be developed as new agents for melanoma treatment.

  14. Irreversible impacts of heat on the emissions of monoterpenes, sesquiterpenes, phenolic BVOC and green leaf volatiles from several tree species

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    E. Kleist

    2012-12-01

    Full Text Available Climate change will induce extended heat waves to parts of the vegetation more frequently. High temperatures may act as stress (thermal stress on plants changing emissions of biogenic volatile organic compounds (BVOCs. As BVOCs impact the atmospheric oxidation cycle and aerosol formation, it is important to explore possible alterations of BVOC emissions under high temperature conditions. Applying heat to European beech, Palestine oak, Scots pine, and Norway spruce in a laboratory setup either caused the well-known exponential increases of BVOC emissions or induced irreversible changes of BVOC emissions. Considering only irreversible changes of BVOC emissions as stress impacts, we found that high temperatures decreased the de novo emissions of monoterpenes, sesquiterpenes and phenolic BVOC. This behaviour was independent of the tree species and whether the de novo emissions were constitutive or induced by biotic stress.

    In contrast, application of thermal stress to conifers amplified the release of monoterpenes stored in resin ducts of conifers and induced emissions of green leaf volatiles. In particular during insect attack on conifers, the plants showed de novo emissions of sesquiterpenes and phenolic BVOCs, which exceeded constitutive monoterpene emissions from pools. The heat-induced decrease of de novo emissions was larger than the increased monoterpene release caused by damage of resin ducts. For insect-infested conifers the net effect of thermal stress on BVOC emissions could be an overall decrease.

    Global change-induced heat waves may put hard thermal stress on plants. If so, we project that BVOC emissions increase is more than predicted by models only in areas predominantly covered with conifers that do not emit high amounts of sesquiterpenes and phenolic BVOCs. Otherwise overall effects of high temperature stress will be lower increases of BVOC emissions than predicted by algorithms that do

  15. A sesquiterpene quinone, dysidine, from the sponge Dysidea villosa, activates the insulin pathway through inhibition of PTPases

    Institute of Scientific and Technical Information of China (English)

    Yu ZHANG; Yan LI; Yue-wei GUO; Hua-liang JIANG; Xu SHEN

    2009-01-01

    Aim: The sesquiterpene hydroquinones/quinones belong to one class of marine sponge metabolites, and they have Accepted considerable attention due to their varied biological activities, including anti-tumor, anti-HIV, and anti-inflammatory action. In order to probe the potential anti-diabetic effect of the sesquiterpene hydroquinones/quinones, the effect of dysi-dine on the insulin pathway was studied.Methods: The promotion of glucose uptake by dysidine was studied in differentiated 3T3-L1 cells. The increase in membrane-located GLUT4 by dysidine was studied in CHO-K1/GLUT4 and 3T3-L1 cells by immuno-staining. The activation of the insulin signaling pathway by dysidine was probed by Western blotting. The inhibition of PTPases by dysidine was detected in vitro.Results: Dysidine, found in the Hainan sponge Dysidea villosa in the Chinese South Sea, effectively activated the insulin signaling pathway, greatly promoted glucose uptake in 3T3-L1 ceils, and showed strong insulin-sensitizing activities. The potential targets of action for dysidine were probed, and the results indicated that dysidine exhibited its cellular effects through activation of the insulin pathway, possibly through the inhibition of protein tyrosine phosphatases, with more specific inhibition against protein tyrosine phosphatase 1B (PTPIB). Conclusion: Our findings are expected to expand understanding of the biological activities of sesquiterpene hydroquino-nes/quinones, and they show that dysidine could be a potential lead compound in the development of an alternative adju-vant in insulin therapy.

  16. Sesquiterpene synthases Cop4 and Cop6 from Coprinus cinereus: Catalytic promiscuity and cyclization of farnesyl pyrophosphate geometrical isomers

    Science.gov (United States)

    Lopez-Gallego, Fernando; Agger, Sean A.; Pella, Daniel A.; Distefano, Mark D.; Schmidt-Dannert, Claudia

    2010-01-01

    Sesquiterpene synthases catalyze with different catalytic fidelity the cyclization of farnesyl pyrophosphate (FPP) into hundreds of known compounds with diverse structures and stereochemistries. Two sesquiterpene synthases, Cop4 and Cop6, were previously isolated from Coprinus cinereus as part of a fungal genome survey. This study investigates the reaction mechanism and catalytic fidelity of the two enzymes. Cyclization of all-trans-FPP ((E,E)-FPP) was compared to the cyclization of the cis-trans isomer of FPP ((Z,E)-FPP) as a surrogate for the secondary cisoid neryl cation intermediate generated by sesquiterpene synthases capable of isomerizing the C2-C3 π bond of all-trans-FPP. Cop6 is a “high-fidelity” α-cuprenene synthase that retains its fidelity under various conditions tested. Cop4 is a catalytically promiscuous enzyme that cyclizes (E,E)-FPP into multiple products, including (−)-germacrene D and cubebol. Changing the pH of the reaction drastically alters the fidelity of Cop4 and makes it a highly selective enzyme. Cyclization of (Z,E)-FPP by Cop4 and Cop6 yields products that are very different from those obtained with (E,E)-FPP. Conversion of (E,E)-FPP proceeds via a (6R)-β-bisabolyl carbocation in the case of Cop6 and an (E,E)-germacradienyl carbocation in the case of Cop4. However, (Z,E)-FPP is cyclized via a (6S)-β-bisabolene carbocation by both enzymes. Structural modeling suggests that differences in the active site and the loop that covers the active site of the two enzymes may explain their different catalytic fidelities. PMID:20419721

  17. Sesquiterpenes from an Egyptian herbal medicine, Pulicaria undulate, with inhibitory effects on nitric oxide production in RAW264.7 macrophage cells.

    Science.gov (United States)

    Hegazy, Mohamed-Elamir F; Matsuda, Hisashi; Nakamura, Seikou; Yabe, Mikuko; Matsumoto, Tomoko; Yoshikawa, Masayuki

    2012-01-01

    The methylene chloride-methanol (1 : 1) extract from the air-dried aerial parts of wild Pulicaria undulata collected in North Sinia, Egypt, showed inhibitory effects on lipopolysaccharide (LPS)-induced production of nitric oxide (NO) in RAW264.7 macrophages. From the extract, three new sesquiterpenes named 5α-hydroperoxyivalin, 8-epi-xanthanol, and 8-epi-isoxanthanol were isolated together with four known sesquiterpenes. The structure of each new sesquiterpenes was determined on the basis of physicochemical and chemical evidence. In addition, all the sesquiterpenoids significantly inhibited the production of NO. Ivalin (IC50=2.0 μM) and 2α-hydroxyalantolactone (1.8 μM) showed particularly strong inhibitory effects, but had strong cytotoxic effects as well. Furthermore, ivalin and 2α-hydroxyalantolactone concentration-dependently reduced inducible NO synthase (iNOS) protein levels in RAW264.7 cells.

  18. A novel cis-selective cyclohexanone annulation as the key step of a total synthesis of the sesquiterpene isoacanthodoral.

    Science.gov (United States)

    Hampel, Thomas; Brückner, Reinhard

    2009-11-05

    Isoacanthodoral (1) is a structurally unique sesquiterpene in that it is a bicyclo[4.4.0]dec-1-ene with a cis- rather than the common trans-junction between the constituting rings. An efficient construction of this motif has been accomplished by a novel cis-selective cyclohexanone annulation, combining the lithium enolate of ester 8, the alpha,beta-unsaturated ester 6, and vinylmagnesium bromide in a single synthetic operation. For completing the total synthesis of 1, a Shapiro-olefination/hydrogenation sequence and a reductive cyanation were employed.

  19. Sesquiterpenes from the stem of Pilocarpus riedelianus and antimicrobial activity; Sesquiterpenos do caule de Pilocarpus riedelianus e atividades sobre microorganismos

    Energy Technology Data Exchange (ETDEWEB)

    Guerreiro, Gisleine; Lima, Janete Eliza S. de; Fernandes, Joao Batista; Silva, M. Fatima das G.F. da; Vieira, Paulo Cezar [Sao Carlos Univ., SP (Brazil). Dept. de Quimica]. E-mail: djbf@power.ufscar.br; Magalhaes, Claudia Maria I.; Pagnocca, Fernando Carlos; Bueno, Odair Correa; Hebling, Maria Jose Aparecida [UNESP, Rio Claro, SP (Brazil). Inst. de Biociencias. Centro de Estudos de Insetos Sociais; Pirani, Jose Rubens [Sao Paulo Univ., SP (Brazil). Inst. de Biociencias. Dept. de Botanica

    2005-11-15

    Pilocarpus riedelianus was studied in order to obtain compounds with activity against fungi and bacteria. The dichloromethane extract, the most active one, was chromatographed yielding hexane and dichloromethane fractions. Six known sesquiterpenes, {alpha}-calacorene, {beta}-calacorene, {gamma}-calacorene, cadalene, sesquichamaenol and 1-hydroxy-1,3,5-bisabolatrien-10-one were identified in the hexane fractions. The identification of these compound was done by NMR and GC/MS analyses. The hexane fraction from the dichloromethane extract showed activity against several fungi and bacteria. (author)

  20. Neonatal exposure to brominated flame retardant BDE-47 reduces long-term potentiation and postsynaptic protein levels in mouse hippocampus

    NARCIS (Netherlands)

    Dingemans, Milou M. L.; Ramakers, Geert M. J.; Gardoni, Fabrizio; van Kleef, Regina G. D. M.; Bergman, Ake; Di Luca, Monica; van den Berg, Martin; Westerink, Remco H. S.; Wijverberg, Henk P. M.

    2007-01-01

    BACKGROUND: Increasing environmental levels of brominated flame retardants raise concern about possible adverse effects, particularly through early developmental exposure. OBJECTIVE: The objective of this research was to investigate neturodevelopmental mechanisms underlying previously observed behav

  1. Biosynthesis of sesquiterpenes in grape berry exocarp of Vitis vinifera L.: evidence for a transport of farnesyl diphosphate precursors from plastids to the cytosol.

    Science.gov (United States)

    May, Bianca; Lange, B Markus; Wüst, Matthias

    2013-11-01

    The participation of the mevalonic acid (MVA) and 1-deoxy-d-xylulose 5-phosphate/2-C-methyl-d-erythritol-4-phosphate (DOXP/MEP) pathways in sesquiterpene biosynthesis of grape berries was investigated. There is an increasing interest in this class of terpenoids, since the oxygenated sesquiterpene rotundone was identified as the peppery aroma impact compound in Australian Shiraz wines. To investigate precursor supply pathway utilization, in vivo feeding experiments were performed with the deuterium labeled, pathway specific, precursors [5,5-(2)H2]-1-deoxy-d-xylulose and [5,5-(2)H2]-mevalonic acid lactone. Head Space-Solid Phase Micro Extraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS) analysis of the generated volatile metabolites demonstrated that de novo sesquiterpene biosynthesis is mainly located in the grape berry exocarp (skin), with no detectable activity in the mesocarp (flesh) of the Lemberger variety. Interestingly, precursors from both the (primarily) cytosolic MVA and plastidial DOXP/MEP pathways were incorporated into grape sesquiterpenes in the varieties Lemberger, Gewürztraminer and Syrah. Our labeling data provide evidence for a homogenous, cytosolic pool of precursors for sesquiterpene biosynthesis, indicating that a transport of precursors occurs mostly from plastids to the cytosol. The labeling patterns of the sesquiterpene germacrene D were in agreement with a cyclization mechanism analogous to that of a previously cloned enantioselective (R)-germacrene D synthase from Solidago canadensis. This observation was subsequently confirmed by enantioselective GC-MS analysis demonstrating the exclusive presence of (R)-germacrene D, and not the (S)-enantiomer, in grape berries.

  2. Hydroxylated polybrominated diphenyl ethers exhibit different activities on thyroid hormone receptors depending on their degree of bromination

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Xiao-Min, E-mail: rxm200318@gmail.com; Guo, Liang-Hong, E-mail: LHGuo@rcees.ac.cn; Gao, Yu, E-mail: francesscototti@gmail.com; Zhang, Bin-Tian, E-mail: nktianster@gmail.com; Wan, Bin, E-mail: binwan@rcees.ac.cn

    2013-05-01

    Polybrominated diphenyl ethers (PBDEs) have been shown to disrupt thyroid hormone (TH) functions in experimental animals, and one of the proposed disruption mechanisms is direct binding of hydroxylated PBDE (OH-PBDE) to TH receptors (TRs). However, previous data on TH receptor binding and TH activity of OH-PBDEs were very limited and sometimes inconsistent. In the present paper, we examined the binding potency of ten OH-PBDEs with different degrees of bromination to TR using a fluorescence competitive binding assay. The results showed that the ten OH-PBDEs bound to TR with potency that correlated to their bromination level. We further examined their effect on TR using a coactivator binding assay and GH3 cell proliferation assay. Different TR activities of OH-PBDEs were observed depending on their degree of bromination. Four low-brominated OH-PBDEs (2′-OH-BDE-28, 3′-OH-BDE-28, 5-OH-BDE-47, 6-OH-BDE-47) were found to be TR agonists, which recruited the coactivator peptide and enhanced GH3 cell proliferation. However, three high-brominated OH-PBDEs (3-OH-BDE-100, 3′-OH-BDE-154, 4-OH-BDE-188) were tested to be antagonists. Molecular docking was employed to simulate the interactions of OH-PBDEs with TR and identify the structural determinants for TR binding and activity. According to the docking results, low-brominated OH-PBDEs, which are weak binders but TR agonists, bind with TR at the inner side of its binding pocket, whereas high-brominated compounds, which are potent binders but TR antagonists, reside at the outer region. These results indicate that OH-PBDEs have different activities on TR (agonistic or antagonistic), possibly due to their different binding geometries with the receptor. - Highlights: ► Thyroid hormone (TH) activity of OH-PBDEs with different Br number was evaluated. ► Four different experimental approaches were employed to investigate the mechanism. ► Low-brominated OH-PBDEs were agonists, but high-brominated ones were antagonists.

  3. The EIMS fragmentation mechanisms of the sesquiterpenes corvol ethers A and B, epi-cubebol and isodauc-8-en-11-ol

    Science.gov (United States)

    Rabe, Patrick

    2016-01-01

    Summary Farnesyl diphosphate (FPP) and all fifteen positional isomers of (13C1)FPP were enzymatically converted by the bacterial terpene cyclases corvol ether synthase from Kitasatospora setae, the epi-cubebol synthase from Streptosporangium roseum, and the isodauc-8-en-11-ol synthase from Streptomyces venezuelae. The enzyme products were analysed by GC–MS and GC–QTOF MS2 and the obtained data were used to delineate the EIMS fragmentation mechanisms of the two sesquiterpene ethers corvol ethers A and B, and the sesquiterpene alcohols epi-cubebol and isodauc-8-en-11-ol. PMID:27559388

  4. Emission of herbivore elicitor-induced sesquiterpenes is regulated by stomatal aperture in maize (Zea mays) seedlings.

    Science.gov (United States)

    Seidl-Adams, I; Richter, A; Boomer, K B; Yoshinaga, N; Degenhardt, J; Tumlinson, J H

    2015-01-01

    Maize seedlings emit sesquiterpenes during the day in response to insect herbivory. Parasitoids and predators use induced volatile blends to find their hosts or prey. To investigate the diurnal regulation of biosynthesis and emission of induced sesquiterpenes, we applied linolenoyl-L-glutamine (LG) to maize seedlings in the morning or evening using a cut-stem assay and tracked farnesene emission, in planta accumulation, as well as transcript levels of farnesyl pyrophosphate synthase 3 (ZmFPPS3) and terpene synthase10 (ZmTPS10) throughout the following day. Independent of time of day of LG treatment, maximum transcript levels of ZmFPPS3 and ZmTPS10 occurred within 3-4 h after elicitor application. The similarity between the patterns of farnesene emission and in planta accumulation in light-exposed seedlings in both time courses suggested unobstructed emission in the light. After evening induction, farnesene biosynthesis increased dramatically during early morning hours. Contrary to light-exposed seedlings dark-kept seedlings retained the majority of the synthesized farnesene. Two treatments to reduce stomatal aperture, dark exposure at midday, and abscisic acid treatment before daybreak, resulted in significantly reduced amounts of emitted and significantly increased amounts of in planta accumulating farnesene. Our results suggest that stomata not only play an important role in gas exchange for primary metabolism but also for indirect plant defences.

  5. Further Study on Chemical Constituents of Parnassia wightiana Wall: Four New Dihydro-β-agarofuran Sesquiterpene Polyesters

    Directory of Open Access Journals (Sweden)

    Zhao-Feng Gao

    2015-04-01

    Full Text Available Four new (1–4, along with six known (5–10 dihydro-β-agarofuran sesquiterpene polyesters were isolated from the whole plants of Parnassia wightiana. The new compounds were structurally elucidated through spectroscopic analysis including UV (Ultraviolet Spectrum, IR (Infrared Spectrum, 1H-NMR (1Hydrogen-Nuclear Magnetic Resonance, 13C-NMR (13Carbon-Nuclear Magnetic Resonance, DEPT (Distortionless Enhancement by Polarization Transfer, 1H-1H COSY (1H-1H Correlation Spectroscopy, HSQC (Heteronuclear Single Quantum Coherence, HMBC (Heteronuclear Multiple Bond Correlation, NOESY (Nuclear Overhauser Enhancement Spectroscopy and HR-MS (High Resolution Mass Specttrum and their absolute configurations were proposed by comparison of NOESY spectra and specific optical rotations with those of known compounds and biosynthesis grounds. Compound 2 is the first sesquiterpene alkaloid isolated from this plant. New compounds 1–4 exhibited some cytotoxic activities against NB4, MKN-45 and MCF-7 cells at 20 μM and of which 4 showed the highest activity against NB4 and MKN-45 cells with inhibition rates of 85.6% and 30.5%, respectively.

  6. Kinetics and mechanism of the oxidative bromination of o-xylene in solution

    Energy Technology Data Exchange (ETDEWEB)

    Dorfman, Ya.A.; Emel' yanova, V.S.; Efremenko, I.G.; Doroshkevich, D.M.; Korolev, A.V.

    1988-07-01

    The kinetics of oxidative bromination of aromatic compounds have been studied in HNO/sub 3/-HBr-H/sub 2/SO/sub 4/-H/sub 2/O-O/sub 2/ solution. A kinetic equation which describes the results was derived for P/sub O/sub 2// > 5 /times/ 10/sup 4/ Pa. The equation parameters were determined at a temperature of 323 K. Quantum mechanical CNDO calculations were carried out in order to study the nature of the reactive intermediates involved: NO/sub 2/ NO(OH)/sup +/, N(OH)/sub 2//sup 2 +/, NO(OH)Br, and N(OH)/sub 2/Br/sup +/. A mechanism has been proposed to account for the oxidative bromination of aromatic compounds in HNO/sub 3/-H/sub 2/SO/sub 4/-HBr-O/sub 2/-H/sub 2/ solution.

  7. A Quaternized Polysulfone Membrane for Zinc-Bromine Redox Flow Battery

    Directory of Open Access Journals (Sweden)

    Mingqiang Li

    2014-01-01

    Full Text Available A quaternized polysulfone (QNPSU composite membrane is fabricated for zinc-bromine redox flow battery. The structure of the membrane is examined by FT-IR spectra and SEM. The conductivity of the membrane is tested by electrochemical analyzer. After a zinc-bromine battery with this composite membrane is operated at different voltage while charging and at different current while discharging to examine the performance of the membrane, it is found that the discharge voltage was 0.9672 V and the power density was 6 mW/cm2 at a current of 0.1 A, which indicated that the novel composite membrane is a promising material for the flow battery.

  8. Co-doping of Potassium and Bromine in Carbon Nanotubes: A Density Functional Theory Study

    Institute of Scientific and Technical Information of China (English)

    XIAO Yong; YAN xiao-Hong; DING Jian-Wen

    2007-01-01

    We investigate the co-doping of potassium and bromine in singlewalled carbon nanotubes (SWCNTs)and doublewalled carbon nanotubes(DWCNTs)based on density functional theory.In the co-doped(6,O)SWCNTs,the 4s electron of potassium is transferred to nanotube and Br,leading to the n-type feature of SWCNTs.When potassium is intercalated into inner tube and bromine is put on outer tube,the positive and negative charges reside on the outer and inner tubes of the(7.0)@(16,0)DWCNT,respectively.It is expected that DWCNTs would be an ideal candidate for p-n junction and diode applications.

  9. Analysis and occurrence of emerging brominated flame retardants in the Llobregat River basin

    Science.gov (United States)

    Guerra, Paula; Eljarrat, Ethel; Barceló, Damià

    2010-03-01

    SummaryIn response to increasing international regulations on brominated flame retardants (BFR) formulations, alternative additive flame retardants for achieving commercial product fire safety standards are being developed and used. Some of these non-BDE (brominated diphenyl ethers) BFRs are pentabromoethylbenzene (PBEB), hexabromobenzene (hexaBBz), and decabromodiphenylethane (deBDethane). The present study investigated the occurrence of these emerging BFRs, together with 38 BDE congeners (from di- to deca-BDE) in sediments sampled from different points along Llobregat basin (Spain) in three different sampling campaigns between 2005 and 2006. Emerging BFRs were detected in all sediment samples analyzed, at concentrations ranging from 3.1 to 9.6 ng/g for PBEB, from 0.4 to 2.4 ng/g for hexaBBz and from 4.8 to 23 ng/g for deBDethane. These levels are lower than concentrations obtained for PBDEs (from nd to 82 ng/g).

  10. A review of mathematical modeling of the zinc/bromine flow cell and battery

    Science.gov (United States)

    Evans, T. I.; White, R. E.

    1987-11-01

    Mathematical models which have been developed to study various aspects of the zinc/bromine cell and stack of cells are reviewed. Development of these macroscopic models begins with a material balance, a transport equation which includes a migration term for charged species in an electric field, and an electrode kinetic expression. Various types of models are discussed: partial differential equation models that can be used to predict current and potential distributions, an algebraic model that includes shunt currents and associated energy losses and can be used to determine the optimum resistivity of an electrolyte, and ordinary differential equation models that can be used to predict the energy efficiency of the cell as a function of the state of charge. These models have allowed researchers to better understand the physical phenomena occurring within parallel plate electrochemical flow reactors and have been instrumental in the improvement of the zinc/bromine cell design. Suggestions are made for future modeling work.

  11. The effect of representing bromine from VSLS on the simulation and evolution of Antarctic ozone

    Science.gov (United States)

    Oman, Luke D.; Douglass, Anne R.; Salawitch, Ross J.; Canty, Timothy P.; Ziemke, Jerald R.; Manyin, Michael

    2016-09-01

    We use the Goddard Earth Observing System Chemistry-Climate Model, a contributor to both the 2010 and 2014 World Meteorological Organization Ozone Assessment Reports, to show that inclusion of 5 parts per trillion (ppt) of stratospheric bromine (Bry) from very short lived substances (VSLS) is responsible for about a decade delay in ozone hole recovery. These results partially explain the significantly later recovery of Antarctic ozone noted in the 2014 report, as bromine from VSLS was not included in the 2010 Assessment. We show multiple lines of evidence that simulations that account for VSLS Bry are in better agreement with both total column BrO and the seasonal evolution of Antarctic ozone reported by the Ozone Monitoring Instrument on NASA's Aura satellite. In addition, the near-zero ozone levels observed in the deep Antarctic lower stratospheric polar vortex are only reproduced in a simulation that includes this Bry source from VSLS.

  12. Formation pathways of brominated products from benzophenone-4 chlorination in the presence of bromide ions

    Institute of Scientific and Technical Information of China (English)

    Ming Xiao; Dongbin Wei; Liping Li; Qi Liu; Huimin Zhao; Yuguo Du

    2014-01-01

    The brominated products,formed in chlorination treatment of benzophenone-4 in the presence of bromide ions,were identified,and the formation pathways were proposed.Under disinfection conditions,benzophenone-4 would undertake electrophilic substitution generating mono-or di-halogenated products,which would be oxidized to esters and further hydrolyzed to phenol derivatives.The generated catechol intermediate would be transformed into furan-like heterocyclic product.The product species were pH-dependent,while benzophenone-4 ehmination was chlorine dose-dependent.When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions,most of brominated byproducts could be detected,and the acute toxicity significantly increased as well.

  13. Improved charge carrier lifetime in planar perovskite solar cells by bromine doping

    OpenAIRE

    Kiermasch, David; Rieder, Philipp; Tvingstedt, Kristofer; Baumann, Andreas; Dyakonov, Vladimir

    2016-01-01

    The charge carrier lifetime is an important parameter in solar cells as it defines, together with the mobility, the diffusion length of the charge carriers, thus directly determining the optimal active layer thickness of a device. Herein, we report on charge carrier lifetime values in bromine doped planar methylammonium lead iodide (MAPbI3) solar cells determined by transient photovoltage. The corresponding charge carrier density has been derived from charge carrier extraction. We found incre...

  14. A comparison of the virucidal properties of chlorine, chlorine dioxide, bromine chloride and iodine.

    OpenAIRE

    Taylor, G. R.; Butler, M.

    1982-01-01

    Chlorine dioxide, bromine chloride and iodine were compared with chlorine as virucidal agents. Under optimal conditions all disinfectants were effective at low concentrations, but each disinfectant responded differently to acidity and alkalinity. Disinfection by chlorine was impaired by the presence of ammonia, but the other disinfectants retained much of their potency. Disinfection of poliovirus by iodine resulted in structural changes in the virions as seen by electron micrroscopy, but the ...

  15. Tropospheric bromine chemistry: implications for present and pre-industrial ozone and mercury

    Directory of Open Access Journals (Sweden)

    J. P. Parrella

    2012-04-01

    Full Text Available We present a new model for the global tropospheric chemistry of inorganic bromine (Bry coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM. Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone concentrations by <1−8 nmol mol−1 (6.5% globally, with the largest effects in the northern extratropics in spring. The global mean tropospheric OH concentration decreases by 4%. Inclusion of bromine chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  16. Brominated and organophosphate flame retardants in selected consumer products on the Japanese market in 2008

    Energy Technology Data Exchange (ETDEWEB)

    Kajiwara, Natsuko, E-mail: kajiwara.natsuko@nies.go.jp [Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan); Noma, Yukio; Takigami, Hidetaka [Research Center for Material Cycles and Waste Management, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506 (Japan)

    2011-09-15

    Highlights: {yields} We examined the flame retardants in electronics, curtains, wallpaper and insulator. {yields} Use of alternative brominated and organophosphate flame retardants was suggested. {yields} All the products investigated also contained PBDEs, TBBPA and polybromophenols. {yields} Incorporation of recycled materials containing hazardous substance was suggested. - Abstract: The concentrations of traditional brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) in new consumer products, including electronic equipment, curtains, wallpaper, and building materials, on the Japanese market in 2008 were investigated. Although some components of the electronic equipment contained bromine at concentrations on the order of percent by weight, as indicated by X-ray fluorescence analysis, the bromine content could not be fully accounted for by the BFRs analyzed in this study, which included polybrominated diphenylethers, decabromodiphenyl ethane, tetrabromobisphenol A, polybromophenols, and hexabromocyclododecanes. These results suggest the use of alternative BFRs such as newly developed formulations derived from tribromophenol, tetrabromobisphenol A, or both. Among the 11 OPFRs analyzed, triphenylphosphate was present at the highest concentrations in all the products investigated, which suggests the use of condensed-type OPFRs as alternative flame retardants, because they contain triphenylphosphate as an impurity. Tripropylphosphate was not detected in any samples; and trimethylphosphate, tributyl tris(2-butoxyethyl)phosphate, and tris(1,3-dichloro-2-propyl)phosphate were detected in only some components and at low concentrations. Note that all the consumer products evaluated in this study also contained traditional BFRs in amounts that were inadequate to impart flame retardancy, which implies the incorporation of recycled plastic materials containing BFRs that are of global concern.

  17. Bromine-catalyzed conversion of CO2 and epoxides to cyclic carbonates under continuous flow conditions.

    Science.gov (United States)

    Kozak, Jennifer A; Wu, Jie; Su, Xiao; Simeon, Fritz; Hatton, T Alan; Jamison, Timothy F

    2013-12-11

    A continuous method for the formation of cyclic carbonates from epoxides and carbon dioxide (CO2) is described. The catalysts used are inexpensive and effective in converting the reagents to the products in a residence time (t(R)) of 30 min. The cyclic carbonate products are obtained in good to excellent yield (51-92%). On the basis of a series of kinetics experiments, we propose a reaction mechanism involving epoxide activation by electrophilic bromine and CO2 activation by an amide.

  18. Tropospheric bromine chemistry: implications for present and pre-industrial ozone and mercury

    Directory of Open Access Journals (Sweden)

    J. P. Parrella

    2012-08-01

    Full Text Available We present a new model for the global tropospheric chemistry of inorganic bromine (Bry coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM. Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by <1–8 nmol mol−1 (6.5% globally, with the largest effects in the northern extratropics in spring. The global mean tropospheric OH concentration decreases by 4%. Inclusion of bromine chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  19. On the age of stratospheric air and inorganic chlorine and bromine release

    Science.gov (United States)

    Daniel, J. S.; Schauffler, S. M.; Pollock, W. H.; Solomon, S.; Weaver, A.; Heidt, L. E.; Garcia, R. R.; Atlas, E. L.; Vedder, J. F.

    1996-07-01

    We estimate the average transport time from the tropical tropopause to various regions of the northern hemisphere lower stratosphere (stratospheric age) using simultaneous mixing ratio measurements of CFC-115 and CO2 measured by the Whole Air Sampler (WAS) during Airborne Arctic Stratospheric Expedition II (AASE II). Our inferred ages are consistent with those presented in previous studies. We discuss sources of uncertainties that affect age estimates in general, as well as specific uncertainties arising from inferring ages using CO2 and CFC-115 abundances. We infer inorganic chlorine (Cly) and bromine (Bry) at various lower stratospheric locations using the WAS organic chlorine and bromine measurements in combination with modeled tropospheric halocarbon trends and with our estimated ages. Inferred Cly and Bry abundances generally increase with increasing latitude and altitude. For our analyzed locations inside the polar vortex, we estimate a maximum Cly abundance of about 2.7 parts per billion by volume (ppbv) and a maximum Bry abundance of about 13.7 parts per trillion by volume (pptv). The locations of these maxima correspond to an average N2O mixing ratio of about 100 ppbv, and to a fractional dissociation of organic chlorine and bromine of 0.85 and 0.90, respectively. Finally, we discuss the expected future limitations of using CFC-115 to estimate stratospheric age due to the production limitations prescribed by the amendments and adjustments to the Montreal Protocol.

  20. Examination of the kinetics of degradation of the antineoplastic drug 5-fluorouracil by chlorine and bromine.

    Science.gov (United States)

    Li, Wei; Tanumihardja, Jessica; Masuyama, Takaaki; Korshin, Gregory

    2015-01-23

    This study examined the degradation of the widely used antineoplastic drug 5-fluorouracil (5FU) by chlorine and bromine. 5FU was determined to interact readily with free chlorine and bromine but was stable in the presence of chloramine. The removal of 5FU followed a second-order kinetic pattern. Apparent rates (kapp) of 5FU removal by chlorine and bromine were strongly pH dependent and had maximum 14.8M(-1)s(-1) and 1.9×10(3)M(-1)s(-1)kapp values, respectively at pH 7. Modeling of the dependence of the kapp values vs. pH indicated the presence of a relatively acidic (pK 6.4 vs. 8.5 of 5FU per se) 5FU intermediate generated in the presence of halogen species. Spectrophotometric measurements confirmed the increased acidity of 5FU chlorination products and allowed proposing a degradation pathway of 5FU by chlorine. This pathway suggests that 5FU chlorination proceeds via chlorine incorporation at the 6th carbon in the heterocyclic ring of 5FU.

  1. Effects of Assistant Solvents and Mixing Intensity on the Bromination Process of Butyl Rubber

    Institute of Scientific and Technical Information of China (English)

    王伟; 邹海魁; 初广文; 向阳; 彭晗; 陈建峰

    2014-01-01

    A slow bromination process of butyl rubber (IIR) suffers from low efficiency and low selectivity (S) of target-product. To obtain suitable approach to intensify the process, effects of assistant solvents and mixing inten-sity on the bromination process were systemically studied in this paper. The reaction process was found constantly accelerated with the increasing dosage and polarity of assistant solvent. Hexane with 30%(by volume) dichloro-methane was found as the suitable solvent component, where the stable conversion of 1,4-isoprene transferring to target product (xA1s) of 80.2%and the corresponding S of 91.2%were obtained in 5 min. The accelerated reaction process was demonstrated being remarkably affected by mixing intensity until the optimal stirring rate of 1100 r·min-1 in a stirred tank reactor. With better mixing condition, a further intensification of the process was achieved in a ro-tating packed bed (RPB) reactor, where xA1s of 82.6% and S of 91.9% were obtained in 2 min. The usage of the suitable solvent component and RPB has potential application in the industrial bromination process intensification.

  2. Computer simulation of the cluster destruction of stratospheric ozone by bromine

    Institute of Scientific and Technical Information of China (English)

    A.E.Galashev; O.R.Rakhmanova

    2012-01-01

    The interaction of (Br-)i(H2O)50-i,0≤i≤6 clusters with oxygen and ozone molecules is investigated by the method of molecular dynamics simulation.The ozone molecules as well as the bromine ions do not leave the cluster during the calculation of 25 ps.The ability of the cluster containing molecular oxygen to absorb the infrared (IR)radiation is reduced in the frequency range of 0 ≤ ω ≤ 3500 cm-1 when the number of the bromine ions in the cluster grows.The intensity of the Raman spectrum is not changed significantly when the Br-ions are added to the ozonecontaining system.The power of the emitted IR radiation is increased when the number of bromine ions grows in the oxygen-containing system.The data obtained in this study on the IR and the Raman spectra of the water clusters that contain ozone,oxygen,and Br-can be used to develop an investigation of the mechanisms of ozone depletion.

  3. Discrimination of hexabromocyclododecane from new polymeric brominated flame retardant in polystyrene foam by nuclear magnetic resonance.

    Science.gov (United States)

    Jeannerat, Damien; Pupier, Marion; Schweizer, Sébastien; Mitrev, Yavor Nikolaev; Favreau, Philippe; Kohler, Marcel

    2016-02-01

    Hexabromocyclododecane (HBCDD) is a brominated flame retardant (BFR) and major additive to polystyrene foam thermal insulation that has recently been listed as a persistent organic pollutant by the Stockholm Convention. During a 2013/2014 field analytical survey, we measured HBCDD content ranging from 0.2 to 2.4% by weight in 98 polystyrene samples. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses indicated that expandable (EPS) and extruded (XPS) polystyrene foams significantly differed in the α/γ HBCDD isomer ratio, with a majority of α and γ isomers in XPS and EPS, respectively. Interestingly, this technique indicated that some recent materials did not contain HBCDD, but demonstrated bromine content when analysed with X-ray fluorescence (XRF). Further investigation by Nuclear Magnetic Resonance (NMR) was able to discriminate between the BFRs present. In addition to confirming the absence or presence of HBCDD in polystyrene samples, high-field NMR spectroscopy provided evidence of the use of brominated butadiene styrene (BBS) as copolymer in the production of polystyrene. Use of this alternative flame retardant is expected to cause fewer health and environmental concerns. Our results highlight a trend towards the use of copolymerized BFRs as an alternative to HBCDD in polystyrene foam boards. In addition to providing a rapid NMR method to identify polymeric BFR, our analytical approach is a simple method to discriminate between flame-retardants in polystyrene foam insulating materials.

  4. Mechanochemical conversion of brominated POPs into useful oxybromides: a greener approach

    Science.gov (United States)

    Cagnetta, Giovanni; Liu, Han; Zhang, Kunlun; Huang, Jun; Wang, Bin; Deng, Shubo; Wang, Yujue; Yu, Gang

    2016-06-01

    Brominated organic pollutants are considered of great concern for their adverse effect on human health and the environment, so an increasing number of such compounds are being classified as persistent organic pollutants (POPs). Mechanochemical destruction is a promising technology for POPs safe disposal because it can achieve their complete carbonization by solvent-free high energy ball milling at room temperature. However, a large amount of co-milling reagent usually is necessary, so a considerable volume of residue is produced. In the present study a different approach to POPs mechanochemical destruction is proposed. Employing stoichiometric quantities of Bi2O3 or La2O3 as co-milling reagent, brominated POPs are selectively and completely converted into their corresponding oxybromides (i.e. BiOBr and LaOBr), which possess very peculiar properties and can be used for some actual and many more potential applications. In this way, bromine is beneficially reused in the final product, while POPs carbon skeleton is safely destroyed to amorphous carbon. Moreover, mechanochemical destruction is employed in a greener and more sustainable manner.

  5. Determination of bromine in regulated foods with a field-portable X-ray fluorescence analyzer.

    Science.gov (United States)

    Anderson, David L

    2009-01-01

    A field-portable X-ray fluorescence analyzer, factory-calibrated for soil analysis, was used to measure bromine (Br) mass fractions in reference materials, flour, bakery products, malted barley, selected U.S. Food and Drug Administration Total Diet Study foods, and other food products. By using a calibration based on instrumental neutron activation analysis results for Br in reference materials, accurate quantitative results, confirmed by z-scores, could be obtained for mass fractions of about 2-55 mg/kg. These results confirmed accuracy of results (with larger uncertainties) obtained by applying a simple correction factor to the analyzer's output value. Results showed that very short analysis times (content at regulatory levels for brominated and enriched brominated flour (24 mg/kg Br) and whole wheat flour and bakery products (36 mg/kg Br). Feasibility for determination of Br in malted barley at the regulatory level (75 mg/kg Br) was demonstrated, but quantitative results at that level could not be assured because no reference material with a suitable mass fraction was available. Br mass fractions for all foods tested were well below regulatory levels.

  6. Brominated and organophosphate flame retardants in selected consumer products on the Japanese market in 2008.

    Science.gov (United States)

    Kajiwara, Natsuko; Noma, Yukio; Takigami, Hidetaka

    2011-09-15

    The concentrations of traditional brominated flame retardants (BFRs) and organophosphate flame retardants (OPFRs) in new consumer products, including electronic equipment, curtains, wallpaper, and building materials, on the Japanese market in 2008 were investigated. Although some components of the electronic equipment contained bromine at concentrations on the order of percent by weight, as indicated by X-ray fluorescence analysis, the bromine content could not be fully accounted for by the BFRs analyzed in this study, which included polybrominated diphenylethers, decabromodiphenyl ethane, tetrabromobisphenol A, polybromophenols, and hexabromocyclododecanes. These results suggest the use of alternative BFRs such as newly developed formulations derived from tribromophenol, tetrabromobisphenol A, or both. Among the 11 OPFRs analyzed, triphenylphosphate was present at the highest concentrations in all the products investigated, which suggests the use of condensed-type OPFRs as alternative flame retardants, because they contain triphenylphosphate as an impurity. Tripropylphosphate was not detected in any samples; and trimethylphosphate, tributyl tris(2-butoxyethyl)phosphate, and tris(1,3-dichloro-2-propyl)phosphate were detected in only some components and at low concentrations. Note that all the consumer products evaluated in this study also contained traditional BFRs in amounts that were inadequate to impart flame retardancy, which implies the incorporation of recycled plastic materials containing BFRs that are of global concern.

  7. Heterogeneous processing of bromine compounds by atmospheric aerosols: Relation to the ozone budget

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, J.M.; Henson, B.F.; Dubey, M.K.; Casson, J.L.; Johal, M.S. [Los Alamos National Lab., NM (US); Wilson, K.R. [Univ. of California, Berkeley, CA (US)

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The depletion of ozone, particularly above Antarctica, has been investigated extensively to formulate public policy on the use of halocarbons. While it has been shown that heterogeneous reactions of chlorine compounds on stratospheric particulates cause the ozone hole, little is known of the analogous bromine mechanisms, even though it has been recognized for two decades that catalytic destruction of ozone by bromine could be more efficient than chlorine. Furthermore, field measurements and modeling calculations suggest that these heterogeneous (gas/surface) reactions are not restricted to the Antarctic regions but occur globally. The authors have performed laboratory measurements of the uptake of bromine compounds and other halogens on simulated stratospheric aerosols to help elucidate their role in catalytic ozone destruction cycles. Their studies contribute to the data base required to make assessments of the effects of human activities on global change, including the Montreal Protocol.

  8. Removal of brominated flame retardant from electrical and electronic waste plastic by solvothermal technique.

    Science.gov (United States)

    Zhang, Cong-Cong; Zhang, Fu-Shen

    2012-06-30

    Brominated flame retardants (BFRs) in electrical and electronic (E&E) waste plastic are toxic, bioaccumulative and recalcitrant. In the present study, tetrabromobisphenol A (TBBPA) contained in this type of plastic was tentatively subjected to solvothermal treatment so as to obtain bromine-free plastic. Methanol, ethanol and isopropanol were examined as solvents for solvothermal treatment and it was found that methanol was the optimal solvent for TBBPA removal. The optimum temperature, time and liquid to solid ratio for solvothermal treatment to remove TBBPA were 90°C, 2h and 15:1, respectively. After the treatment with various alcohol solvents, it was found that TBBPA was finally transferred into the solvents and bromine in the extract was debrominated catalyzed by metallic copper. Bisphenol A and cuprous bromide were the main products after debromination. The morphology and FTIR properties of the plastic were generally unchanged after the solvothermal treatment indicating that the structure of the plastic maintained after the process. This work provides a clean and applicable process for BFRs-containing plastic disposal.

  9. A satellite based study of tropospheric bromine explosion events and their linkages to polar cyclone development

    Science.gov (United States)

    Blechschmidt, Anne-Marlene; Richter, Andreas; Burrows, John P.; Kaleschke, Lars; Strong, Kimberly; Theys, Nicolas; Weber, Mark; Zhao, Xiaoyi; Zien, Achim; Hodges, Kevin I.

    2016-04-01

    Intense, cyclone-like shaped plumes of tropospheric bromine monoxide (BrO) are regularly observed by the UV-vis satellite instruments GOME-2/MetOp-A and SCIAMACHY/Envisat over Arctic and Antarctic sea ice in polar spring. The plumes are associated with an autocatalytic chemical chain reaction involving tropospheric ozone depletion and initiated by the release of bromine from cold brine-covered ice or snow to the atmosphere. This influences atmospheric chemistry as it affects the oxidising capacity of the troposphere through OH production and may also influence the local weather/temperature of the polar atmosphere, as ozone is a major greenhouse gas. Here, we make combined use of satellite retrievals and numerical model simulations to study individual BrO plume cases in the polar atmosphere. In agreement with previous studies, our analysis shows that the plumes are often transported by high latitude cyclones, sometimes over several days despite the short atmospheric lifetime of BrO. Moreover, general characteristics of bromine explosion events linked to transport by polar weather systems, such as frequency, spatial distribution and favourable weather conditions are derived based on a new detection method. Our results show that BrO cyclone transport events are by far more common in the Antarctic than in the Arctic.

  10. Enhanced crystal grain size by bromine doping in electrodeposited Cu{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Han Kunhee; Kang Feng [Department of Electrical Engineering, University of Texas at Arlington, Arlington, TX 76019 (United States); Han Xiaofei [Department of Material Science and Engineering, University of Texas at Arlington, Arlington, TX 76019 (United States); Tao Meng, E-mail: meng.tao@asu.edu [Department of Electrical Engineering, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2012-06-01

    Extremely large crystal grains are obtained by bromine doping in electrodeposited Cu{sub 2}O on indium tin oxide (ITO) substrate through an acetate bath. The grains are as large as 10,000 {mu}m{sup 2} in area, or {approx} 100 {mu}m in linear dimension, while the film is only 1-5 {mu}m thick. The enhanced grain size is explained by the effect of over-potential for the Cu{sup 2+}/Cu{sup +} redox couple on nucleation density of Cu{sub 2}O on ITO substrate. The over-potential is a function of several deposition conditions including solution pH, deposition potential, deposition temperature, bromine precursor concentration, and copper precursor concentration. In addition, undoped Cu{sub 2}O displays a high resistivity of 100 M{Omega}cm. Bromine doping in Cu{sub 2}O significantly reduces the resistivity to as low as 42 {Omega}cm after vacuum annealing. Br-doped Cu{sub 2}O shows n-type behavior. - Highlights: Black-Right-Pointing-Pointer Extremely large crystal grains ({approx} 100 {mu}m) achieved in electrodeposited Br-doped Cu{sub 2}O. Black-Right-Pointing-Pointer Large grains reduce carrier recombination and carrier scattering at grain boundaries. Black-Right-Pointing-Pointer N-type behavior demonstrated in naturally p-type Cu{sub 2}O by Br doping.

  11. MISCIBILITY AND MORPHOLOGY OF THIN FILMS OF BLENDS OF POLYSTYRENE WITH BROMINATED POLYSTYRENES: EFFECTS OF VARYING THE MOLECULAR WEIGHT,BROMINATION DEGREE AND ANNEALING

    Institute of Scientific and Technical Information of China (English)

    Rui Song; De-bin Yang; Ling-hao He; Guang-tao Yao

    2006-01-01

    Thin films of incompatible polymer blends can form a variety of structures during preparation and subsequent annealing process. For the polymer blend system consisting of polystyrene and poly(styrene-co-p-bromo-styrene), I.e.,PS/PBrxS, its compatibility could be adjusted by varying the degree of bromination and the molecular weight of both components comprised. In this paper, surface chemical compositions of the cast and the annealing films were investigated by X-ray photoelectron spectroscopy (XPS) and contact angle measurement; meanwhile, surface topographical changes are followed by atomic force microscopy (AFM). In addition, substantial attention was paid to the effect of annealing on the morphologic variations induced by phase separation and/or dewetting of the thin film. Moreover, the influences of the molecular weight, Mw, as well as the brominated degree, x%, on the sample surface are explored systematically, and the corresponding observations are explained in virtue of the Flory-Huggins theory, along with the dewetting of the polymer thin film.

  12. Study Of The Fundamental Physical Principles in Atmospheric Modeling Based On Identification Of Atmosphere - Climate Control Factors: Bromine Explosion At The Polar Arctic Sunrise

    OpenAIRE

    Iudin, M.

    2007-01-01

    We attempt is to provide accumulated evidence and qualitative understanding of the associated atmospheric phenomena of the Arctic bromine explosion and their role in the functioning of the biotic Earth. We rationalize the empirical expression of the bromine influx into atmospheric boundary layer and calculate total amounts of the tropospheric BrO and Bry of the Arctic origin. Based on the quantities and partitioning of the reactive bromine species, we estimate the biogeochemical parametric co...

  13. Bromine monoxide / sulphur dioxide ratios in relation to volcanological observations at Mt. Etna 2006–2009

    Directory of Open Access Journals (Sweden)

    G. Giuffrida

    2012-12-01

    Full Text Available Over a 3-yr period, from 2006 to 2009, frequent scattered sunlight DOAS measurements were conducted at Mt. Etna at a distance of around 6 km downwind from the summit craters. During the same period and in addition to these measurements, volcanic observations were made by regularly visiting various parts of Mt. Etna. Here, results from these measurements and observations are presented and their relation is discussed. The focus of the investigation is the bromine monoxide/sulphur dioxide (BrO / SO2 ratio, and its variability in relation to volcanic processes. That the halogen/sulphur ratio can serve as a precursor or indicator for the onset of eruptive activity was already proposed by earlier works (e.g. Noguchi and Kamiya 1963; Menyailov, 1975; Pennisi and Cloarec, 1998; Aiuppa et al., 2002. However, there is still a limited understanding today because of the complexity with which halogens are released, depending on magma composition and degassing conditions. Our understanding of these processes is far from complete, for example of the rate and mechanism of bubble nucleation, growth and ascent in silicate melts (Carroll and Holloway, 1994, the halogen vapour-melt partitioning and the volatile diffusivity in the melt (Aiuppa et al., 2009. With this study we aim to add one more piece to the puzzle of what halogen/sulphur ratios might tell about volcanic activities. Our data set shows an increase of the BrO / SO2 ratio several weeks prior to an eruption, followed by a decline before and during the initial phase of eruptive activities. Towards the end of activity or shortly thereafter, the ratio increases to baseline values again and remains more or less constant during quiet phases. To explain the observed evolution of the BrO / SO2 ratio, a first empirical model is proposed. This model suggests that bromine, unlike chlorine and fluorine, is less soluble in the magmatic melt than sulphur. By using the DOAS method to determine SO2, we actually

  14. Brominated flame retardants and organochlorine pollutants in eggs of little owls (Athene noctua) from Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, Veerle [Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Covaci, Adrian [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium)]. E-mail: adrian.covaci@ua.ac.be; Maervoet, Johan [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Dauwe, Tom [Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Voorspoels, Stefan [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Schepens, Paul [Toxicological Centre, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium); Eens, Marcel [Department of Biology, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Wilrijk (Belgium)

    2005-07-15

    Residues of brominated diphenylethers (PBDEs), organochlorinated pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in 40 eggs of little owls (Athene noctua), a terrestrial top predator from Belgium. The major organohalogens detected were PCBs (median 2,600 ng/g lipid, range 790-23000 ng/g lipid). PCB 153,138/163, 170, 180 and 187 were the predominant congeners and constituted 71% of total sum PCBs. PBDEs were measurable in all samples, but their concentrations were much lower than for PCBs, with a range from 29-572 ng/g lipid (median 108 ng/g lipid). The most prevalent PBDE congeners in little owl egg samples were BDE 47, 99 and 153. This profile differs from the profile in marine bird species, for which BDE 47 was the dominant congener, indicating that terrestrial birds may be more exposed to higher brominated BDE congeners than marine birds. The fully brominated BDE 209 could be detected in one egg sample (17 ng/g lipid), suggesting that higher brominated BDEs may accumulate in terrestrial food chains. Brominated biphenyl (BB) 153 was determined in all egg samples, with levels ranging from 0.6 to 5.6 ng/g lipid (median 1.3 ng/g lipid). Additionally, hexabromocyclododecane (HBCD) could be identified and quantified in only two eggs at levels of 20 and 50 ng/g lipid. OCPs were present at low concentrations, suggesting a rather low contamination of the sampled environment with OCPs (median concentrations of sum DDTs: 826 ng/g lipid, sum chlordanes: 1,016 ng/g lipid, sum HCHs: 273 ng/g lipid). Hexachlorobenzene (HCB) and octachlorostyrene (OCS) were also found at low median levels of 134 and 3.4 ng/g lipid, respectively. Concentrations of most analytes were significantly higher in eggs collected from deserted nests in comparison to addled (unhatched) eggs, while eggshell thickness did not differ between deserted and addled eggs. No significant correlations were found between eggshell thickness and the analysed organohalogens. - PBDEs are measurable

  15. Effects of Acute Ozone Exposure and Methyl Jasmonate Treatment on White Pine Monoterpene and Sesquiterpene Emission Rates

    Science.gov (United States)

    Faiola, C. L.; Wagner, D.; Allwine, E.; Harley, P. C.; Vanreken, T. M.

    2010-12-01

    Biogenic volatile organic compounds (BVOCs) are produced by plants and include monoterpenes, sesquiterpenes, and their oxygenated derivatives. These BVOCs are one of the principal factors influencing the oxidative capacity of the atmosphere in forested regions, and impact both ozone concentration and secondary organic aerosol formation. Under unstressed conditions, the release of BVOCs to the atmosphere is primarily controlled by the vapor pressure of the relevant compounds within the plant tissue, which is in turn dependent on temperature as well as complex biochemical production processes. However, various natural and anthropogenic stressors can alter both the quantity and composition of the BVOCs emitted by plants. Many potential stressors are expected to become stronger as climate change effects escalate. The impacts of most stressors on BVOC emissions have not been well characterized, particularly in a field setting where changes in BVOC emissions could have influential feedbacks with climate. This study investigated the effects of two stressors on monoterpene and sesquiterpene emission rates at a field site in northern Michigan: acute ozone exposure and treatment with methyl jasmonate, an herbivory proxy. The study included six repetitions of the same experiment, each time using a new set of sub-canopy eastern white pine specimens. For each experiment, dynamic branch enclosures were simultaneously used on three specimens for sample collection: one ozone treatment tree, one methyl jasmonate treatment tree, and one control tree. Sampling lines were placed in each enclosure and VOCs were collected onto cartridges packed with Tenax GR adsorbent. Samples were collected several times per day for at least two days before treatment and for five days after treatment. Cartridges were analyzed via thermodesorption with an Agilent GC/MS/FID. This analysis allowed the identification and quantification of several monoterpene and sesquiterpene species in the samples

  16. Genotoxic action of the sesquiterpene lactone glaucolide B on mammalian cells in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Regislaine V. Burim

    1999-09-01

    Full Text Available Glaucolide B is a sesquiterpene lactone isolated from Vernonia eremophila Mart. (Vernonieae, Asteraceae and has schistosomicidal, antimicrobial and analgesic activities. This study examined the cytotoxic and clastogenic activities of glaucolide B in human cultured lymphocytes and in bone marrow cells from BALB/c mice. The mitotic index (MI and chromosomal aberrations were analyzed in both of the above systems, whereas sister chromatid exchanges (SCE and the proliferation index (PI were determined only in vitro. In human cultured lymphocytes, glaucolide B concentrations greater than 15 µg/ml of culture medium completely inhibited cell growth. At 4 µg/ml and 8 µg/ml of culture medium, glaucolide B significantly increased the frequency of chromosomal aberrations in lymphocytes and was also cytotoxic at concentrations ³8 µg/ml; there was no increase in the frequency of SCE. Glaucolide B (160-640 mg/kg did not significantly increase the frequency of chromosomal aberrations in mouse bone marrow cells nor did it affect cell division. Since glaucolide B showed no clastogenic action on mammalian cells in vivo but was cytotoxic and clastogenic in vitro, caution is needed in its medicinal use.O glaucolido B é uma lactona sesquiterpênica, g-lactona a,b-insaturada, isolada da Vernonia eremophila Mart. (Vernonieae, Asteraceae; apresenta atividade esquistossomicida e antimicrobiana, além de atividade analgésica. A aceitação de uma substância para uso medicinal também depende de dados sobre sua toxicidade, além de sua eficiência medicinal. Assim, o objetivo deste trabalho foi testar a atividade clastogênica e citotóxica do composto glaucolido B in vitro e in vivo, utilizando linfócitos em cultura temporária e células da medula óssea de camundongos BALB/c, respectivamente. Analisaram-se o índice mitótico (MI e as aberrações cromossômicas nos sistemas in vitro e in vivo, e trocas entre cromátides irmãs (SCE e índice proliferativo (PI

  17. SF002-96-1, a new drimane sesquiterpene lactone from an Aspergillus species, inhibits survivin expression

    Directory of Open Access Journals (Sweden)

    Silke Felix

    2013-12-01

    Full Text Available Survivin, a member of the IAP (inhibitor of apoptosis gene family, is overexpressed in virtually all human cancers and is functionally involved in the inhibition of apoptosis, regulation of cell proliferation, metastasis and resistance to therapy. Because of its upregulation in malignancy, survivin has currently attracting considerable interest as a new target for anticancer therapy. In a screening of approximately 200 strains of imperfect fungi for the production of inhibitors of survivin promoter activity, a new drimane sesquiterpene lactone, SF002-96-1, was isolated from fermentations of an Aspergillus species. The compound inhibited survivin promoter activity in transiently transfected Colo 320 cells in a dose dependent manner with IC50 values of 3.42 µM (1.3 µg/mL. Moreover, it also reduced mRNA levels and protein synthesis of survivin and triggered apoptosis.

  18. 3-Ishwarone, a Rare Ishwarane Sesquiterpene from Peperomia scandens Ruiz & Pavon: Structural Elucidation through a Joint Experimental and Theoretical Study

    Directory of Open Access Journals (Sweden)

    Fernando M. dos S.

    2013-10-01

    Full Text Available 3-Ishwarone, (1, a sesquiterpene with a rare ishwarane skeleton, was isolated from Peperomia scandens Ruiz & Pavon (Piperaceae. Its structure was unambiguously determined by 1D- and 2D-NMR and infrared analyses, as well as by comparative theoretical studies which involved calculations of 13C-NMR chemical shifts, using the Density Functional Theory (DFT with the mPW1PW91 hybrid functional and Pople’s 6-31G(d basis set, and of vibrational frequencies, using the B3LYP hybrid functional and triple ζ Dunning’s correlation consistent basis set (cc-pVTZ, of (1 and three of its possible diastereomers, compounds 2–4.

  19. Novel sesquiterpenes from Schisandra grandiflora: isolation, cytotoxic activity and synthesis of their triazole derivatives using "click" reaction.

    Science.gov (United States)

    Poornima, B; Siva, Bandi; Shankaraiah, G; Venkanna, A; Nayak, V Lakshma; Ramakrishna, Sistla; Venkat Rao, C; Babu, K Suresh

    2015-03-01

    Phytochemical investigation of hexane extract from the fruits of Schisandra grandiflora afforded three novel sesquiterpenes (1-3) along with the three known compounds (4-6). The structures of these isolates were determined by extensive analysis of spectroscopic data (1D, 2D NMR). Further, a series of triazole analogues of 3 and 4 were prepared using "Click" reaction protocol. The reaction scheme involving one-carbon homologation of 3 and 4 using the Bestmann-Ohira reagent followed by regioselective Huisgen 1,3-dipolar cycloaddition reaction of various azides leading to the formation of triazole analogues (20a-20k &21a-21c) which is being reported for the first time. All the triazole products were characterized using spectral data analysis. The anti-proliferative activity of the isolates and the synthetic analogues were studied against Hela (Cervical cancer), A549 (Lung cancer), DU-145 (Prostate cancer), MCF-7 (Breast cancer) and B-16 (Mouse melanoma) cancer cell lines.

  20. Preparative isolation of guaipyridine sesquiterpene alkaloid from Artemisia rupestris L. flowers using high-speed counter-current chromatography.

    Science.gov (United States)

    Su, Zhen; Wu, Hankui; Yang, Yi; Aisa, Haji Akber; Slukhan, Usmanova; Aripova, Salimakhon

    2008-07-01

    Although the medicinal plant Artemisia rupestris L. has been widely researched for several decades, its alkaloids have never been isolated before. To our surprise, the alkaloids in the plant were not detected in the stems but detected in the flowers. Herein, a novel and strange guaipyridine sesquiterpene alkaloid with a carboxyl group named rupestine was purified successfully from the total alkaloids extracted from the flowers by high-speed counter-current chromatography (HSCCC). The two-phase solvent system used was composed of ethyl acetate-methanol-water (8:1:7, v/v/v). Fifty six milligrams of rupestine was obtained at over 97% purity and 95% recovery from 200 mg of the total alkaloids in one-step separation. Its structure was elucidated by spectroscopic methods including high resolution ESI-MS, (1)H NMR, (13)C NMR, Heteronuclear Multiple Bond Correlation (HMBC), Heteronuclear Single Quantum Coherence (HSQC), and Nuclear Overhauser Enhancement Spectroscopy (NOESY).

  1. Induction of sesquiterpene cyclase and suppression of squalene synthetase activities in plant cell cultures treated with fungal elicitor.

    Science.gov (United States)

    Vögeli, U; Chappell, J

    1988-12-01

    Addition of elicitor, cell wall fragments of the fungus Phytophthora parasitica, to tobacco cell suspension cultures (Nicotiana tabacum) resulted in the rapid synthesis and secretion of large amounts of antibiotic sesquiterpenoids. Pulse-labeling experiments with [(14)C]acetate and [(3)H] mevalonate demonstrated that the induction of sesquiterpenoid biosynthesis, maximal by 6 to 9 hours after elicitor addition to the cell cultures, was paralleled by a rapid and large decline in the incorporation rate of radioactivity into sterols. Consequently, sterol accumulation was also inhibited upon addition of elicitor to the cell cultures. Sesquiterpene cyclase activity was absent from control cell cultures but induced to a maximum within 10 hours of elicitor addition to the cell cultures. The cyclase activity remained elevated for an additional 30 hours before declining. In contrast, squalene synthetase activity was suppressed to less than 15% of that found in control cells within 7 hours of elicitor addition. Our results suggest that the channeling of isoprenoid intermediates, and especially farnesyl diphosphate, into sesquiterpenoids occurred by a coordinated increase in the sesquiterpene cyclase and a decrease in the squalene synthetase enzyme activities. A reexamination of the data pertaining to the transient induction of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity (EC 1.1.1.34) in elicitor-treated cells suggested that, while the reductase activity was necessary for sesquiterpenoid biosynthesis, it functioned more to maintain a sufficient level of intermediates between mevalonate and farnesyl diphosphate rather than as a rate limiting step controlling the synthesis rate of any one class of isoprenoids.

  2. Tropospheric Bromine Chemistry: Implications for Present and Pre-industrial Ozone and Mercury

    Science.gov (United States)

    Parella, J. P.; Jacob, D. J.; Liang, Q.; Zhang, Y.; Mickley, L. J.; Miller, B.; Evans, M. J.; Yang, X.; Pyle, J. A.; Theys, N.; VanRoozendael, M.

    2012-01-01

    We present a new model for the global tropospheric chemistry of inorganic bromine (Bry) coupled to oxidant-aerosol chemistry in the GEOS-Chem chemical transport model (CTM). Sources of tropospheric Bry include debromination of sea-salt aerosol, photolysis and oxidation of short-lived bromocarbons, and transport from the stratosphere. Comparison to a GOME-2 satellite climatology of tropospheric BrO columns shows that the model can reproduce the observed increase of BrO with latitude, the northern mid-latitudes maximum in winter, and the Arctic maximum in spring. This successful simulation is contingent on the HOBr + HBr reaction taking place in aqueous aerosols and ice clouds. Bromine chemistry in the model decreases tropospheric ozone mixing ratios by chemistry improves the ability of global models (GEOS-Chem and p-TOMCAT) to simulate observed 19th-century ozone and its seasonality. Bromine effects on tropospheric ozone are comparable in the present-day and pre-industrial atmospheres so that estimates of anthropogenic radiative forcing are minimally affected. Br atom concentrations are 40% higher in the pre-industrial atmosphere due to lower ozone, which would decrease by a factor of 2 the atmospheric lifetime of elemental mercury against oxidation by Br. This suggests that historical anthropogenic mercury emissions may have mostly deposited to northern mid-latitudes, enriching the corresponding surface reservoirs. The persistent rise in background surface ozone at northern mid-latitudes during the past decades could possibly contribute to the observations of elevated mercury in subsurface waters of the North Atlantic.

  3. Distribution of copper, silver and gold during thermal treatment with brominated flame retardants.

    Science.gov (United States)

    Oleszek, Sylwia; Grabda, Mariusz; Shibata, Etsuro; Nakamura, Takashi

    2013-09-01

    The growing consumption of electric and electronic equipment results in creating an increasing amount of electronic waste. The most economically and environmentally advantageous methods for the treatment and recycling of waste electric and electronic equipment (WEEE) are the thermal techniques such as direct combustion, co-combustion with plastic wastes, pyrolysis and gasification. Nowadays, this kind of waste is mainly thermally treated in incinerators (e.g. rotary kilns) to decompose the plastics present, and to concentrate metals in bottom ash. The concentrated metals (e.g. copper, precious metals) can be supplied as a secondary raw material to metal smelters, while the pyrolysis of plastics allows the recovery of fuel gases, volatilising agents and, eventually, energy. Indeed, WEEE, such as a printed circuit boards (PCBs) usually contains brominated flame retardants (BFRs). From these materials, hydrobromic acid (HBr) is formed as a product of their thermal decomposition. In the present work, the bromination was studied of copper, silver and gold by HBr, originating from BFRs, such as Tetrabromobisphenol A (TBBPA) and Tetrabromobisphenol A-Tetrabromobisophenol A diglycidyl ether (TTDE) polymer; possible volatilization of the bromides formed was monitored using a thermo-gravimetric analyzer (TGA) and a laboratory-scale furnace for treating samples of metals and BFRs under an inert atmosphere and at a wide range of temperatures. The results obtained indicate that up to about 50% of copper and silver can evolve from sample residues in the form of volatile CuBr and AgBr above 600 and 1000°C, respectively. The reactions occur in the molten resin phase simultaneously with the decomposition of the brominated resin. Gold is resistant to HBr and remains unchanged in the residue.

  4. Production of HBR from bromine and steam for off-peak electrolytic hydrogen generation

    Energy Technology Data Exchange (ETDEWEB)

    Schlief, R.E.; Hanrahan, R.J.; Stoy, M.A. [Univ. of Florida, Gainesville, FL (United States)] [and others

    1995-09-01

    Progress is reported on the development of a renewable energy source based solar-electrolytic system for production of hydrogen and oxygen. It employs water, bromine, solar energy and supplemental electrical power. The concept is being developed by Solar Reactor Technologies, Inc., (SRT), with the U.S. Department of Energy (DOE). An overview of the nature and objectives of this program is provided here, and technical progress made during the first (three-month) performance period of the Phase I work effort is reported. The SRT concept entails (1) absorption of concentrated solar radiation by bromine vapor Br{sub 2(g)} in a high-temperature reactor producing Br{sub (g)} atoms, (2) reaction of Br{sub (g)} with water yielding hydrogen bromide (HBr), and (3) electrolysis of stored hydrogen bromide for production of H{sub 2(g)} and recovery of Br{sub 2(I)}. Incorporation of solar radiation in the primary photochemical step (1) reduces by 50 - 70% the electrical power required to split water. The SRT concept is very attractive from an economic viewpoint as well. The reversible fuel cell, employed in the SRT electrolysis concept is capitalized via its use in load leveling by the utility. A 1 kW solar reactor was designed and constructed during the first three-month performance period by SRT personnel at the University of Florida, Gainesville. It was employed in taking survey data of the reaction between bromine and steam at temperatures between 900 and 1300 K. This reaction was run under purely thermal conditions, i.e. in the absence of solar photons. The experimental data are reported and interpreted employing concomitant thermodynamic calculations. The anticipated improvement is discussed briefly as well as the effect of a photochemical boost to the reaction. The amount of this enhancement will be studied in the next three month performance period.

  5. Effect of brominated furanones on the formation of biofilm by Escherichia coli on polyvinyl chloride materials.

    Science.gov (United States)

    Lianhua, Ye; Yunchao, Huang; Geng, Xu; Youquang, Zhou; Guangqiang, Zhao; Yujie, Lei

    2013-01-01

    To study the influence of brominated furanones on the biofilm (BF) formation by Escherichia coli (E. coli) on polyvinyl chloride (PVC) material, and to provide new ways of surface modification of materials to clinically prevent biomaterial centered infection. Three brominated furanones, dissolved in ethanol, furanone-1(3,4-dibromo-5-hydroxyl-furanone), furanone-2(4-bromo-5-(4-methoxypheny)-3-(methylamino)-furanone), and furanone-3(3,4-dibromo-5,5-dimethoxypheny-2(5H)-furanone) with representative chemical structure, were coated on the surfaces of separate PVC materials (1 × 1 cm), respectively. The surface-modified PVC materials were incubated with E. coli and for controls, 75 % ethanol-treated PVC materials were used. This treatment played as control group. The cultivation incubations were for 6, 12, 18, and 24 h. The thickness of bacterial BF and bacterial community quantity unit area on the PVC materials was determined by confocal laser scanning microscopy (CLSM), and the surface structure of bacterial BF formation was examined by scanning electron microscopy (SEM). The results of CLSM indicated the thickness of bacterial BF and bacterial community quantity unit area on PVC materials treated with furanone-3 were significantly lower than that of control at all time points (P 0.05). The results of SEM indicated that after 6 h incubation, the quantity of bacterial attachment to the surface of PVC material treated with furanone-3 was lower than the control group. By 18 h incubation there was completely formed BF structure on the surface of control PVC material. However, there was no significant BF formation on the surface of PVC material treated with furanone-3. The impact of different brominated furanones on SA biofilm formation on the surface of PVC materials are different, furanone-3 can inhibit E. coli biofilm formation on the surface of PVC material.

  6. Ways of reducing the bromine numbers of benzene for nitration with the use of the piperylene additive

    Energy Technology Data Exchange (ETDEWEB)

    Kolyandr, L.Ya.; Litvinenko, A.M.; Mastyukov, V.A.; Potapchenko, A.A.; Savikkova, M.T.; Shoherbakova, T.G.; Shuzhenko, E.A.; Titarenko, V.G.; Tkachenko, L.A.

    1981-01-01

    To study the diminution of the bromine numbers of benzene for nitration, an investigation has been made of the impurities according to the fractions of the tests of benzene production of three coke and chemical works: the works in Makeev-a, ka, Bagleisk and Yenakievo. It has been found that when the piperylene additive is used, the value of the bromine numbers of benzene for nitration is determined, in the main, not by the piperylenes removed during purification. When the intermediate BT fractions are not sufficiently clearly selected, the value of the bromine numbers of benzene is influenced also by the impurities which are concentrated in its terminal fractions. To radically remove piperylenes, it is necessary to improve the contact between the acid and the fraction being purified; this is attained by intensifying mixing and lengthening the purification process.

  7. Package of double helical bromine chains inside single-walled carbon nanotubes

    Science.gov (United States)

    Yao, Zhen; Liu, Chun Jian; Lv, Hang; Yang, Xi Bao

    2016-10-01

    The helicity of stable double helical bromine chains inside single-walled carbon nanotubes (SWCNTs) was studied through the calculation of systematic interaction energy, using the van der Waals interaction potential. The results presented clear images of stable double helical structures inside SWCNTs. The optimal helical radius and helical angle of chain structure increase and decrease, respectively, with the increase of tube radius. The detailed analysis indicated that some metastable structures in SWCNTs may also co-exist with the optimal structures, but not within the same tubes. In addition, a detailed simulation of X-ray diffraction patterns was performed for the obtained optimal helical structures.

  8. SYNTHESIS AND GREEN BROMINATION OF SOME CHALCONES AND THEIR ANTIMICROBIAL SCREENING

    Directory of Open Access Journals (Sweden)

    Mayur R. Adokar

    2013-04-01

    Full Text Available Chalcones are the versatile molecules having the structural flexibility which permits structural transformations into flavonoids, flavanones, pyrazoles, oxazoles, pyrimidines etc. Changes in their structure have offered the development of new medicinal agents having improved pharmacological potency. Their derivatives have attracts increasing attention due to numerous pharmacological potential. In the present communication we report the synthesis of chalcones from various acetophenone derivatives with different aromatic aldehydes and green chemistry approach to their bromination with the help of Tetrabutylammonium Tribromide (TBATB. All the synthesized chalcone dibromides were screened for their antimicrobial activity against Aspergillus flavus, Rhizopus sp., Fusarium solani and Aspergillus niger.

  9. Brominated flame retardants in waste electrical and electronic equipment: substance flows in a recycling plant.

    Science.gov (United States)

    Morf, Leo S; Tremp, Josef; Gloor, Rolf; Huber, Yvonne; Stengele, Markus; Zennegg, Markus

    2005-11-15

    Brominated flame retardants (BFRs) are synthetic additives mainly used in electrical and electronic appliances and in construction materials. The properties of some BFRs are typical for persistent organic pollutants, and certain BFRs, in particular some polybrominated diphenyl ether (PBDE) congeners and hexabromocyclododecane (HBCD), are suspected to cause adverse health effects. Global consumption of the most demanded BFRs, i.e., penta-, octa-, and decaBDE, tetrabromobisphenol A (TBBPA), and HBCD, has doubled in the 1990s. Only limited and rather uncertain data are available regarding the occurrence of BFRs in consumer goods and waste fractions as well as regarding emissions during use and disposal. The knowledge of anthropogenic substance flows and stocks is essential for early recognition of environmental impacts and effective chemicals management. In this paper, actual levels of penta-, octa-, and decaBDE, TBBPA, and HBCD in waste electrical and electronic equipment (WEEE) as a major carrier of BFRs are presented. These BFRs have been determined in products of a modern Swiss recycling plant applying gas chromatography/electron capture detection and gas chromatography/mass spectrometry analysis. A substance flow analysis (SFA) technique has been used to characterize the flows of target substances in the recycling process from the bulk WEEE input into the output products. Average concentrations in small size WEEE, representing the relevant electric and electronic appliances in WEEE, sampled in 2003 amounted to 34 mg/kg for pentaBDE, 530 mg/kg for octaBDE, 510 mg/kg for decaBDE, 1420 mg/kg for TBBPA (as an additive), 17 mg/kg for HBCD, 5500 mg/kg for bromine, and 1700 mg/kg for antimony. In comparison to data that have been calculated by SFA for Switzerland from literature for the 1990s, these measured concentrations in small size WEEE were 7 times higher for pentaBDE, unexpectedly about 50% lower for decaBDE, and agreed fairly well for TBBPA (as an additive) and

  10. Theoretical performance of hydrogen-bromine rechargeable SPE fuel cell. [Solid Polymer Electrolyte

    Science.gov (United States)

    Savinell, R. F.; Fritts, S. D.

    1988-01-01

    A mathematical model was formulated to describe the performance of a hydrogen-bromine fuel cell. Porous electrode theory was applied to the carbon felt flow-by electrode and was coupled to theory describing the solid polymer electrolyte (SPE) system. Parametric studies using the numerical solution to this model were performed to determine the effect of kinetic, mass transfer, and design parameters on the performance of the fuel cell. The results indicate that the cell performance is most sensitive to the transport properties of the SPE membrane. The model was also shown to be a useful tool for scale-up studies.

  11. Antibacterial Activities of a New Brominated Diterpene from Borneon Laurencia spp

    Science.gov (United States)

    Vairappan, Charles Santhanaraju; Ishii, Takahiro; Lee, Tan Kai; Suzuki, Minoru; Zhaoqi, Zhan

    2010-01-01

    In our continuous interest to study the diversity of halogenated metabolites of Malaysian species of the red algal genus Laurencia, we examined the chemical composition of five populations of unrecorded Laurencia sp. A new brominated diterpene, 10-acetoxyangasiol (1), and four other known metabolites, aplysidiol (2), cupalaurenol (3), 1-methyl-2,3,5-tribromoindole (4), and chamigrane epoxide (5), were isolated and identified. Isolated metabolites exhibited potent antibacterial activities against clinical bacteria, Staphylococcus aureus, Staphylococcus sp., Streptococcus pyogenes, Salmonella sp. and Vibrio cholerae. PMID:20631866

  12. Antibacterial Activities of a New Brominated Diterpene from Borneon Laurencia spp.

    Directory of Open Access Journals (Sweden)

    Charles Santhanaraju Vairappan

    2010-05-01

    Full Text Available In our continuous interest to study the diversity of halogenated metabolites of Malaysian species of the red algal genus Laurencia, we examined the chemical composition of five populations of unrecorded Laurencia sp. A new brominated diterpene, 10-acetoxyangasiol (1, and four other known metabolites, aplysidiol (2, cupalaurenol (3, 1-methyl-2,3,5-tribromoindole (4, and chamigrane epoxide (5, were isolated and identified. Isolated metabolites exhibited potent antibacterial activities against clinical bacteria, Staphylococcus aureus, Staphylococcus sp., Streptococcus pyogenes, Salmonella sp. and Vibrio cholerae.

  13. Highly Oxygenated Sesquiterpene Lactones from Cousinia aitchisonii and their Cytotoxic Properties: Rhaserolide Induces Apoptosis in Human T Lymphocyte (Jurkat) Cells via the Activation of c-Jun n-terminal Kinase Phosphorylation.

    Science.gov (United States)

    Iranshahy, Milad; Tayarani-Najaran, Zahra; Kasaian, Jamal; Ghandadi, Morteza; Emami, Seyed Ahmad; Asili, Javad; Chandran, Jima N; Schneider, Bernd; Iranshahi, Mehrdad

    2016-02-01

    Infrared-guided chromatographic fractionation of sesquiterpene lactones from the extracts of Cousinia aitchisonii and Cousinia concolor led to the isolation of five pure compounds. A new sesquiterpene lactone, namely, aitchisonolide, and two known sesquiterpene lactones (desoxyjanerin and rhaserolide) were isolated from C. aitchisonii and two known lignans (arctiin and arctigenin) from C. concolor. The structures of these compounds were elucidated by one-dimensional and two-dimensional nuclear magnetic resonance techniques, as well as high-resolution mass spectrometry. The purified and characterized compounds were subjected to cytotoxicity assay. The sesquiterpene lactones desoxyjanerin and rhaserolide showed significant cytotoxic activities against five different cancer cell lines and the normal human embryonic kidney cell line. Rhaserolide was chosen to evaluate the possible mechanism of action. Western blot analysis revealed that rhaserolide could induce apoptosis in Jurkat cells via the activation of c-Jun n-terminal kinase phosphorylation.

  14. Characterization of Some Real Mixed Plastics from WEEE: A Focus on Chlorine and Bromine Determination by Different Analytical Methods

    Directory of Open Access Journals (Sweden)

    Beatrice Beccagutti

    2016-10-01

    Full Text Available Bromine and chlorine are almost ubiquitous in waste of electrical and electronic equipment (WEEE and the knowledge of their content in the plastic fraction is an essential step for proper end of life management. The aim of this study is to compare the following analytical methods: energy dispersive X-ray fluorescence spectroscopy (ED-XRF, ion chromatography (IC, ion-selective electrodes (ISEs, and elemental analysis for the quantitative determination of chlorine and bromine in four real samples taken from different WEEE treatment plants, identifying the best analytical technique for waste management workers. Home-made plastic standard materials with known concentrations of chlorine or bromine have been used for calibration of ED-XRF and to test the techniques before the sample analysis. Results showed that IC and ISEs, based upon dissolution of the products of the sample combustion, have not always achieved a quantitative absorption of the analytes in the basic solutions and that bromine could be underestimated since several oxidation states occur after combustion. Elemental analysis designed for chlorine determination is subjected to strong interference from bromine and required frequent regeneration and recalibration of the measurement cell. The most reliable method seemed to be the non-destructive ED-XRF. Calibration with home-made standards, having a similar plastic matrix of the samples, enabled us to carry out quantitative determinations, which have been revealed to be satisfactorily accurate and precise. In all the analyzed samples a total concentration of chlorine and/or bromine between 0.6 and 4 w/w% was detected, compromising the feasibility of a mechanical recycling and suggesting the exploration of an alternative route for managing these plastic wastes.

  15. Electrospun Nafion®/Polyphenylsulfone Composite Membranes for Regenerative Hydrogen Bromine Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jun Woo Park

    2016-02-01

    Full Text Available The regenerative H2/Br2-HBr fuel cell, utilizing an oxidant solution of Br2 in aqueous HBr, shows a number of benefits for grid-scale electricity storage. The membrane-electrode assembly, a key component of a fuel cell, contains a proton-conducting membrane, typically based on the perfluorosulfonic acid (PFSA ionomer. Unfortunately, the high cost of PFSA membranes and their relatively high bromine crossover are serious drawbacks. Nanofiber composite membranes can overcome these limitations. In this work, composite membranes were prepared from electrospun dual-fiber mats containing Nafion® PFSA ionomer for facile proton transport and an uncharged polymer, polyphenylsulfone (PPSU, for mechanical reinforcement, and swelling control. After electrospinning, Nafion/PPSU mats were converted into composite membranes by softening the PPSU fibers, through exposure to chloroform vapor, thus filling the voids between ionomer nanofibers. It was demonstrated that the relative membrane selectivity, referenced to Nafion® 115, increased with increasing PPSU content, e.g., a selectivity of 11 at 25 vol% of Nafion fibers. H2-Br2 fuel cell power output with a 65 μm thick membrane containing 55 vol% Nafion fibers was somewhat better than that of a 150 μm Nafion® 115 reference, but its cost advantage due to a four-fold decrease in PFSA content and a lower bromine species crossover make it an attractive candidate for use in H2/Br2-HBr systems.

  16. Development of Zinc/Bromine Batteries for Load-Leveling Applications: Phase 2 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    CLARK,NANCY H.; EIDLER,PHILLIP

    1999-10-01

    This report documents Phase 2 of a project to design, develop, and test a zinc/bromine battery technology for use in utility energy storage applications. The project was co-funded by the U.S. Department of Energy Office of Power Technologies through Sandia National Laboratories. The viability of the zinc/bromine technology was demonstrated in Phase 1. In Phase 2, the technology developed during Phase 1 was scaled up to a size appropriate for the application. Batteries were increased in size from 8-cell, 1170-cm{sup 2} cell stacks (Phase 1) to 8- and then 60-cell, 2500-cm{sup 2} cell stacks in this phase. The 2500-cm{sup 2} series battery stacks were developed as the building block for large utility battery systems. Core technology research on electrolyte and separator materials and on manufacturing techniques, which began in Phase 1, continued to be investigated during Phase 2. Finally, the end product of this project was a 100-kWh prototype battery system to be installed and tested at an electric utility.

  17. Biodegradation kinetics of selected brominated flame retardants in aerobic and anaerobic soil

    Energy Technology Data Exchange (ETDEWEB)

    Nyholm, Jenny Rattfelt, E-mail: jenny.rattfelt@chem.umu.s [Department of Chemistry, Umea University, SE-901 87 Umea (Sweden); Lundberg, Charlott; Andersson, Patrik L. [Department of Chemistry, Umea University, SE-901 87 Umea (Sweden)

    2010-06-15

    The purpose of the present study was to investigate the biodegradation kinetics in aerobic and anaerobic soil of the following brominated flame retardants: 2,4,4'-tribromodiphenyl ether (BDE 28), decabromodiphenyl ether (BDE 209), tetrabromobisphenol A (TBBPA), 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH), 2,4,6-tribromophenol (246BrPh), and hexabromobenzene (HxBrBz). For comparison, the biodegradation of the chlorinated compounds 2,4,4'-trichlorodiphenyl ether (CDE 28), 2,4,6-trichlorophenol (246ClPh), hexachlorobenzene (HxClBz), and 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153) was also assessed. In aerobic soil, BDE 209 showed no significant degradation during the test period, but concentrations of the other BFRs declined, with half-lives decreasing in the following order: BDE 28 > TBBPA > TBECH > HxBrBz > 246BrPh. Declines in almost the same order were observed in anaerobic soil: BDE 28, BDE 209 > TBBPA > HxBrBz > TBECH >246BrPh. - Intra- and extrapolated half-lives in soil of tested brominated flame retardants ranged from 7 days for 2,4,6-tribromorophenol to >400 days for decabromodiphenyl ether.

  18. Hair as an indicator of endogenous tissue levels of brominated flame retardants in mammals.

    Science.gov (United States)

    D'Havé, Helga; Covaci, Adrian; Scheirs, Jan; Schepens, Paul; Verhagen, Ron; De Coen, Wim

    2005-08-15

    Few data are available on brominated flame retardants (BFRs) in terrestrial mammalian wildlife. Moreover, the use of hair in nondestructive monitoring of BFRs in mammals or humans has not been investigated. In the present study, concentrations of polybrominated diphenyl ethers (PBDEs) and brominated biphenyl 153 (BB 153) were analyzed in tissues of the European hedgehog Erinaceus europaeus. Road kills and carcasses from wildlife rescue centers were used to investigate relationships between concentrations of BFRs in hair and internal tissues, BFR tissue distribution (hair, liver, kidney, muscle, and adipose tissue), and PBDE congener tissue pattern dissimilarities. Liver concentrations of PBDEs and BB 153 were in the ranges 1-1178 and 0-2.5 ng/g of liver wet weight, respectively. PBDEs were predominant in adipose tissue and liver, while accumulation of BB 153 was tissue independent. The less persistent compound BDE 99 was more dominant in hair than in internal tissues. We observed positive relationships between BFR levels in hair and internal tissues for sum PBDEs and BDE 47 (0.37 terrestrial mammals which can be used in nondestructive monitoring schemes.

  19. Synthesis of α-Bromine- Terminated Polystyrene Macroinitiator and Its Initiation of MMA Polymerization by ATRP

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In the present paper the synthesis of block copolymers via the transformation from living anionic polymerization (LAP) to atom transfer radical polymerization (ATRP) was described. Α-Bromine-terminated polystyrenes(PStBr) in the LAP step was prepared by using n-BuLi as initiator, tetrahydrofuran (THF) as the activator, α-methylstyrene (α-MeSt) as the capping group and liquid bromine (Br2) as the bromating agent. The effects of reaction conditions such as the amounts of α-MeSt, THF, and Br2 as well as molecular weight of polystyrene on the bromating efficiency (BE) and coupling extent (CE) were examined. The present results show that the yield of PStBr obtained was more than 93.8% and the coupling reaction was substantially absent. PStBr was further used as the macroinitiator in the polymerization of methyl-methacrylate(MMA) in the presence of copper(Ⅰ) halogen and 2,2-bipyridine(bpy) complexes. It was found that the molecular weight of the resulted PSt-b-PMMA increased linearly with the increase of the conversion of MMA and the polydispersity was 1.2-1.6. The structures of PStBr and P(St-b-MMA) were characterized by 1H NMR spectra.

  20. Novel Spectrophotometric Method for Determination of Macro-paracetamol via Reaction with Bromine

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The reaction between Br2 and paracetamol(p-AAP) leads to the formation of a coloured product, which can be used for spectrophotometric determination of the p-AAP content in its pure form and in different pharmaceutical preparations with p-AAP. The stoichiometric composition of the reaction was found to be n(p-AAP)∶n(bromine)=1∶3. The effects of pH and time on the spectra of p-AAP-bromine redox reaction product were studied. The interference of different additives on the measured spectra of the obtained product was also studied. The results obtained by the present method were compared with those obtained by the standard method. The F- and t- test values were calculated for both of the applied procedures and they met a confidence level of 99%. The proposed procedure actually needs no separation of these drugs from their sources before analysis and was unaffected by interference of other phenolic compounds. The proposed method is simpler and faster than the repoeted ones.

  1. Brominated diphenyl ethers in the sediments, porewater, and biota of the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K.; Klosterhaus, S.; Liebert, D.; Stapleton, H. [Maryland Univ., Solomons, MD (United States)

    2004-09-15

    Levels of brominated diphenyl ethers (BDEs) are rapidly increasing in the environment, and in a short time these chemicals have evolved from 'emerging contaminants' to globally-distributed organic pollutants. Recent research demonstrates BDEs are sufficiently stable to be transported long distances in the environment and to accumulate in higher trophic levels. Photolysis and metabolism appear to be dominant loss processes for the parent compounds, generating a variety of lower brominated diphenyl ethers, hydroxylated metabolites, and other products. BDEs are hydrophobic, and therefore their transport in aquatic systems is likely controlled by sorption to sediments and perhaps exchange across the air-water interface. To date, few studies have examined the geochemistry of BDEs in natural waters. In this paper, we review our recent measurements of BDEs in the Chesapeake Bay, a shallow, productive estuary in eastern North America. We focus on the distribution of BDE congeners sediment, porewater, and in faunal benthos along a contamination gradient downstream from a wastewater treatment plant and on the spatial distribution of BDEs in bottom-feeding and pelagic fish species.

  2. Dissolution of brominated epoxy resins by dimethyl sulfoxide to separate waste printed circuit boards.

    Science.gov (United States)

    Zhu, Ping; Chen, Yan; Wang, Liangyou; Qian, Guangren; Zhang, Wei Jie; Zhou, Ming; Zhou, Jin

    2013-03-19

    Improved methods are required for the recycling of waste printed circuit boards (WPCBs). In this study, WPCBs (1-1.5 cm(2)) were separated into their components using dimethyl sulfoxide (DMSO) at 60 °C for 45 min and a metallographic microscope was used to verify their delamination. An increased incubation time of 210 min yielded a complete separation of WPCBs into their components, and copper foils and glass fibers were obtained. The separation time decreased with increasing temperature. When the WPCB size was increased to 2-3 cm(2), the temperature required for complete separation increased to 90 °C. When the temperature was increased to 135 °C, liquid photo solder resists could be removed from the copper foil surfaces. The DMSO was regenerated by rotary decompression evaporation, and residues were obtained. Fourier transform infrared spectroscopy (FT-IR), thermal analysis, nuclear magnetic resonance, scanning electron microscopy, and energy-dispersive X-ray spectroscopy were used to verify that these residues were brominated epoxy resins. From FT-IR analysis after the dissolution of brominated epoxy resins in DMSO it was deduced that hydrogen bonding may play an important role in the dissolution mechanism. This novel technology offers a method for separating valuable materials and preventing environmental pollution from WPCBs.

  3. Natural solar photolysis of total organic chlorine, bromine and iodine in water.

    Science.gov (United States)

    Abusallout, Ibrahim; Hua, Guanghui

    2016-04-01

    Municipal wastewater has been increasingly used to augment drinking water supplies due to the growing water scarcity. Wastewater-derived disinfection byproducts (DBPs) may negatively affect the aquatic ecosystems and human health of downstream communities during water reuse. The objective of this research was to determine the degradation kinetics of total organic chlorine (TOCl), bromine (TOBr) and iodine (TOI) in water by natural sunlight irradiation. Outdoor solar photolysis experiments were performed to investigate photolytic degradation of the total organic halogen (TOX) formed by fulvic acid and real water and wastewater samples. The results showed that TOX degradation by sunlight irradiation followed the first-order kinetics with half-lives in the range of 2.6-10.7 h for different TOX compounds produced by fulvic acid. The TOX degradation rates were generally in the order of TOI > TOBr ≅ TOCl(NH2Cl) > TOCl(Cl2). High molecular weight TOX was more susceptible to solar photolysis than corresponding low molecular weight halogenated compounds. The nitrate and sulfite induced indirect TOX photolysis rates were less than 50% of the direct photolysis rates under the conditions of this study. Fulvic acid and turbidity in water reduced TOX photodegradation. These results contribute to a better understanding of the fate of chlorinated, brominated and iodinated DBPs in surface waters.

  4. Nitrogenous disinfection byproducts in English drinking water supply systems: Occurrence, bromine substitution and correlation analysis.

    Science.gov (United States)

    Bond, Tom; Templeton, Michael R; Mokhtar Kamal, Nurul Hana; Graham, Nigel; Kanda, Rakesh

    2015-11-15

    Despite the recent focus on nitrogenous disinfection byproducts in drinking water, there is limited occurrence data available for many species. This paper analyses the occurrence of seven haloacetonitriles, three haloacetamides, eight halonitromethanes and cyanogen chloride in 20 English drinking water supply systems. It is the first survey of its type to compare bromine substitution factors (BSFs) between the haloacetamides and haloacetonitriles. Concentrations of the dihalogenated haloacetonitriles and haloacetamides were well correlated. Although median concentrations of these two groups were lower in chloraminated than chlorinated surface waters, median BSFs for both in chloraminated samples were approximately double those in chlorinated samples, which is significant because of the higher reported toxicity of the brominated species. Furthermore, median BSFs were moderately higher for the dihalogenated haloacetamides than for the haloacetonitriles. This indicates that, while the dihalogenated haloacetamides were primarily generated from hydrolysis of the corresponding haloacetonitriles, secondary formation pathways also contributed. Median halonitromethane concentrations were remarkably unchanging for the different types of disinfectants and source waters: 0.1 μg · mgTOC(-1) in all cases. Cyanogen chloride only occurred in a limited number of samples, yet when present its concentrations were higher than the other N-DBPs. Concentrations of cyanogen chloride and the sum of the halonitromethanes were not correlated with any other DBPs.

  5. Sesquiterpenes and other constituents from leaves of Pterodon pubescens Benth (Leguminosae); Sesquiterpenos e outros constituintes das folhas de Pterodon pubescens Benth (Leguminosae)

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Mayker Lazaro Dantas; Garcez, Fernanda Rodrigues; Garcez, Walmir Silva, E-mail: walmir.garcez@ufms.br [Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Instituto de Quimica; Abot, Alfredo Raul [Universidade Estadual de Mato Grosso do Sul (UEMS), Aquidauana, MS (Brazil)

    2014-05-15

    In addition to β-sitosterol, stigmasterol, phaeophitin A, luteolin, kaempferol, quercetin, (+)-catechin, quercetin-3-O-α-L-rhamnopyranoside, rutin, and p-hydroxy-benzoic acid, six known sesquiterpenes, namely (rel)-2β,6β-epoxy-5β-hydroxy-isodaucane, oplopanone, 1β,6α-dihydroxy-4(15)-eudesmene, caryophyllene oxide, α-cadinol, and spathulenol, were isolated from the leaves of Pterodon pubescens (Leguminosae) growing in the Cerrado of Mato Grosso do Sul, Brazil. The (rel)-2β,6β-epoxy-5β-hydroxy-isodaucane corresponds to the correct structure of homalomenol D. The sesquiterpene oplopanone, which bears a modified cadinane skeleton, is being reported for the first time in this genus. The structures of the compounds were determined on the basis of spectral data (MS, IR, and NMR-1D and 2D) and subsequent comparison with data reported in the literature. (author)

  6. Sesquiterpene Lactone Composition and Cellular Nrf2 Induction of Taraxacum officinale Leaves and Roots and Taraxinic Acid β-d-Glucopyranosyl Ester.

    Science.gov (United States)

    Esatbeyoglu, Tuba; Obermair, Betina; Dorn, Tabea; Siems, Karsten; Rimbach, Gerald; Birringer, Marc

    2017-01-01

    Taraxacum officinale, the common dandelion, is a plant of the Asteraceae family, which is used as a food and medical herb. Various secondary plant metabolites such as sesquiterpene lactones, triterpenoids, flavonoids, phenolic acids, coumarins, and steroids have been described to be present in T. officinale. Dandelion may exhibit various health benefits, including antioxidant, anti-inflammatory, and anticarcinogenic properties. We analyzed the leaves and roots of the common dandelion (T. officinale) using high-performance liquid chromatography/mass spectrometry to determine its sesquiterpene lactone composition. The main compound of the leaf extract taraxinic acid β-d-glucopyranosyl ester (1), a sesquiterpene lactone, was isolated and the structure elucidation was conducted by nuclear magnetic resonance spectrometry. The leaf extract and its main compound 1 activated the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in human hepatocytes more significantly than the root extract. Furthermore, the leaf extract induced the Nrf2 target gene heme oxygenase 1. Overall, present data suggest that compound 1 may be one of the active principles of T. officinale.

  7. The Influence of Sesquiterpenes from Myrica rubra on the Antiproliferative and Pro-Oxidative Effects of Doxorubicin and Its Accumulation in Cancer Cells.

    Science.gov (United States)

    Ambrož, Martin; Boušová, Iva; Skarka, Adam; Hanušová, Veronika; Králová, Věra; Matoušková, Petra; Szotáková, Barbora; Skálová, Lenka

    2015-08-21

    The sesquiterpenes β-caryophyllene, β-caryophyllene oxide (CAO), α-humulene (HUM), trans-nerolidol (NER), and valencene (VAL) are substantial components of the essential oil from Myrica rubra leaves which has exhibited significant antiproliferative effects in several intestinal cancer cell lines, with CaCo-2 cells being the most sensitive. The present study was designed to evaluate the effects of these sesquiterpenes on the efficacy and toxicity of the anticancer drug doxorubicin (DOX) in CaCo-2 cancer cells and in primary culture of rat hepatocytes. Our results showed that HUM, NER, VAL and CAO inhibited proliferation of CaCo-2 cancer cells but they did not affect the viability of hepatocytes. CAO, NER and VAL synergistically potentiated the efficacy of DOX in cancer cells killing. All sesquiterpenes exhibited the ability to selectively increase DOX accumulation in cancer cells and did not affect DOX concentration in hepatocytes. Additionally, CAO and VAL were able to increase the pro-oxidative effect of DOX in CaCo-2 cells. Moreover, CAO mildly ameliorated DOX toxicity in hepatocytes. Based on all results, CAO seems to be the most promising compound for further testing.

  8. The Influence of Sesquiterpenes from Myrica rubra on the Antiproliferative and Pro-Oxidative Effects of Doxorubicin and Its Accumulation in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Martin Ambrož

    2015-08-01

    Full Text Available The sesquiterpenes β-caryophyllene, β-caryophyllene oxide (CAO, α-humulene (HUM, trans-nerolidol (NER, and valencene (VAL are substantial components of the essential oil from Myrica rubra leaves which has exhibited significant antiproliferative effects in several intestinal cancer cell lines, with CaCo-2 cells being the most sensitive. The present study was designed to evaluate the effects of these sesquiterpenes on the efficacy and toxicity of the anticancer drug doxorubicin (DOX in CaCo-2 cancer cells and in primary culture of rat hepatocytes. Our results showed that HUM, NER, VAL and CAO inhibited proliferation of CaCo-2 cancer cells but they did not affect the viability of hepatocytes. CAO, NER and VAL synergistically potentiated the efficacy of DOX in cancer cells killing. All sesquiterpenes exhibited the ability to selectively increase DOX accumulation in cancer cells and did not affect DOX concentration in hepatocytes. Additionally, CAO and VAL were able to increase the pro-oxidative effect of DOX in CaCo-2 cells. Moreover, CAO mildly ameliorated DOX toxicity in hepatocytes. Based on all results, CAO seems to be the most promising compound for further testing.

  9. Virtual Screening of Plant Volatile Compounds Reveals a High Affinity of Hylamorpha elegans (Coleoptera: Scarabaeidae) Odorant-Binding Proteins for Sesquiterpenes From Its Native Host

    Science.gov (United States)

    Palma-Millanao, Rubén; Yáñez, Osvaldo; Rojas, Maximiliano; Mutis, Ana; Venthur, Herbert; Quiroz, Andrés; Ramírez, Claudio C.

    2016-01-01

    Hylamorpha elegans (Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs in H. elegans as well as six new volatiles released by its native host Nothofagus obliqua (Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. obliqua revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies. PMID:27012867

  10. Virtual Screening of Plant Volatile Compounds Reveals a High Affinity of Hylamorpha elegans (Coleoptera: Scarabaeidae) Odorant-Binding Proteins for Sesquiterpenes From Its Native Host.

    Science.gov (United States)

    González-González, Angélica; Palma-Millanao, Rubén; Yáñez, Osvaldo; Rojas, Maximiliano; Mutis, Ana; Venthur, Herbert; Quiroz, Andrés; Ramírez, Claudio C

    2016-01-01

    Hylamorpha elegans(Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals. Here, we report the discovery of four OBPs inH. elegans as well as six new volatiles released by its native host Nothofagus obliqua(Mirbel). Molecular docking performed between OBPs and new and previously reported volatiles from N. oblique revealed the best binding energy values for sesquiterpenic compounds. Despite remarkable divergence at the amino acid level, three of the four OBPs evaluated exhibited the best interaction energy for the same ligands. Molecular dynamics investigation reinforced the importance of sesquiterpenes, showing that hydrophobic residues of the OBPs interacted most frequently with the tested ligands, and binding free energy calculations demonstrated van der Waals and hydrophobic interactions to be the most important. Altogether, the results suggest that sesquiterpenes are interesting candidates for in vitro and in vivo assays to assess their potential application in pest management strategies.

  11. Subacute effects of the brominated flame retardants hexabromocyclododecane and tetrabromobisphenol A on hepatic cytochrome P450 levels in rats.

    NARCIS (Netherlands)

    Germer, Silke; Piersma, Aldert H; Ven, Leo T M van der; Kamyschnikow, Andreas; Fery, Yvonne; Schmitz, Hans-Joachim; Schrenk, Dieter

    2006-01-01

    The brominated flame retardants tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are found in the environment, e.g., in sediments and organisms, in food items, human blood samples and mother's milk. In this study, the effects of both compounds on rat hepatic cytochrome P450 (CYP) leve

  12. Rapid Formation of Molecular Bromine from Deliquesced NaBr Aerosol in the Presence of Ozone and UV Light

    Science.gov (United States)

    The formation of gas-phase bromine from aqueous sodium bromide aerosols is investigated through a combination of chamber experiments and chemical kinetics modeling. Experiments show that Br2(g) is produced rapidly from deliquesced NaBr aerosols in the presence of OH radicals prod...

  13. Exposure to brominated trihalomethanes in water during pregnancy and micronuclei frequency in maternal and cord blood lymphocytes

    DEFF Research Database (Denmark)

    Stayner, Leslie Thomas; Pedersen, Marie; Patelarou, Evridiki;

    2014-01-01

    BACKGROUND: Water disinfection by-products have been associated with an increased cancer risk. Micronuclei (MN) frequency in lymphocytes is a marker of genomic damage and can predict adult cancer risk. OBJECTIVE: We evaluated maternal exposure to drinking water brominated trihalomethanes (BTHM) i...

  14. Prenatal Exposure to Organohalogens, Including Brominated Flame Retardants, Influences Motor, Cognitive, and Behavioral Performance at School Age

    NARCIS (Netherlands)

    Roze, Elise; Meijer, Lisethe; Bakker, Attie; Van Braeckel, Koenraad N. J. A.; Sauer, Pieter J. J.; Bos, Arend F.

    2009-01-01

    BACKGROUND: Organohalogen compounds (OHCs) are known to have neurotoxic effects on the developing brain. OBJECTIVE: We investigated the influence of prenatal exposure to OHCs, including brominated flame retardants, on motor, cognitive, and behavioral outcome in healthy children of school age. METHOD

  15. Suppressing effect of calcium-based waste on control of bromine flux during the pyrolysis of printed circuit boards.

    Science.gov (United States)

    Jie, Guan; Min, Xu; Wu, Wenjie; Zhang, Chenglong; Wang, Jingwei; Bai, Jianfeng

    2012-11-01

    The effect of calcium-based addition on the brominate flux during printed circuit board (PCB) pyrolysis was investigated. It was found that bromine (Br) can be effectively fixed in solid phase during PCB pyrolysis by adding calcium-based waste materials. Phenol and 4-ethylphenol are the major products of pyrolysis. When the two kinds of red mud were used as additive, their content was 85.25 and 84.81%, respectively, which was higher than others. The 2-bromophenol and 2-bromo-4-methyl-benzene are the main Br-containing pyrolysis volatiles. After adding calcium-based additive, these two volatiles were apparently reduced and only small amounts of 2-bromo-4-methyl-benzene were detected in the products, namely 0.71 and 0.86%, respectively for the two kinds of red mud. Hence, no matter from the perspective of product use or simple Br-fixing, the bromine in the three-phase products can be effectively regulated and controlled by adding calcium-based waste residue during PCB pyrolysis. Finally, the Br-fixing mechanism was analysed. As a result, when calcium-based waste materials were added to the PCB pyrolysis it made bromine fix easily in the resident yielding a byproduct that can be further used.

  16. Temporal development of brominated flame retardants in peregrine falcon (Fako peregrinus) eggs from South Greenland (1986-2003)

    NARCIS (Netherlands)

    Vorkamp, K.; Thomsen, M.; Falk, K.; Leslie, H.A.; Moller, S.; Sorensen, P.B.

    2005-01-01

    A time trend between 1986 and 2003 was found for brominated flame retardants in peregrine falcon eggs from South Greenland, with significantly increasing concentrations of the polybrominated diphenyl ethers (PBDEs) 99, 100, 153, 154, and 209. For BDE-99 and -100, the concentration increased approxim

  17. Bromination of Aromatic Compounds by Residual Bromide in Sodium Chloride Matrix Modifier Salt During Heated Headspace GC/MS Analysis

    Science.gov (United States)

    Analytical artifacts attributed to the bromination of toluene, xylenes, and trimethylbenzenes were found during the heated headspace gas chromatography/mass spectrometry (GC/MS) analysis of aqueous samples. The aqueous samples were produced from Fenton-like chemical oxidation rea...

  18. The detection of some halogenated phenols and nitrophenols in thin-layer chromatography by means of bromine

    NARCIS (Netherlands)

    Tadema, G.; Batelaan, P.H.

    1968-01-01

    A method is described for the detection of halogeno- and nitro-phenols in sub-microgram quantities. Theses compounds are made visible by exposure of the developed thin layer plates to bromine vapour and subsequent spraying with an aqueous solution of potassium iodide or an ethanolic solution of fluo

  19. Corrosion mechanism of 13Cr stainless steel in completion fluid of high temperature and high concentration bromine salt

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yan [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Xu, Lining, E-mail: xulining@ustb.edu.cn [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Lu, Minxu [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China); Meng, Yao [Beijing Institute of Aeronautical Materials, Beijing 100095 (China); Zhu, Jinyang; Zhang, Lei [Corrosion and Protection Center, Key Laboratory for Environmental Fracture (MOE), Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083 (China)

    2014-09-30

    Highlights: • The corrosion behavior of 13Cr steel exposed to bromine salt completion fluid containing high concentration bromine ions was investigated. • There are passive circles around pits on the 13Cr steel surface after 7 d of exposure. • Macroscopic galvanic corrosion formed between the passive halo and the pit. • The mechanism of pitting corrosion on 13Cr stainless steel exposed to heavy bromine brine was established. - Abstract: A series of corrosion tests of 13Cr stainless steel were conducted in a simulated completion fluid environment of high temperature and high concentration bromine salt. Corrosion behavior of specimens and the component of corrosion products were investigated by means of scanning electron microscope (SEM), confocal laser scanning microscopy (CLSM) and X-ray photoelectron spectroscopy (XPS). The results indicate that 13Cr steel suffers from severe local corrosion and there is always a passive halo around every pit. The formation mechanism of the passive halo is established. OH{sup −} ligand generates and adsorbs in a certain scale because of abundant OH{sup −} on the surface around the pits. Passive film forms around each pit, which leads to the occurrence of passivation in a certain region. Finally, the dissimilarities in properties and morphologies of regions, namely the pit and its corresponding passive halo, can result in different corrosion sensitivities and may promote the formation of macroscopic galvanic pairs.

  20. Reaction of bromine and chlorine with phenolic compounds and natural organic matter extracts--Electrophilic aromatic substitution and oxidation.

    Science.gov (United States)

    Criquet, Justine; Rodriguez, Eva M; Allard, Sebastien; Wellauer, Sven; Salhi, Elisabeth; Joll, Cynthia A; von Gunten, Urs

    2015-11-15

    Phenolic compounds are known structural moieties of natural organic matter (NOM), and their reactivity is a key parameter for understanding the reactivity of NOM and the disinfection by-product formation during oxidative water treatment. In this study, species-specific and/or apparent second order rate constants and mechanisms for the reactions of bromine and chlorine have been determined for various phenolic compounds (phenol, resorcinol, catechol, hydroquinone, phloroglucinol, bisphenol A, p-hydroxybenzoic acid, gallic acid, hesperetin and tannic acid) and flavone. The reactivity of bromine with phenolic compounds is very high, with apparent second order rate constants at pH 7 in the range of 10(4) to 10(7) M(-1) s(-1). The highest value was recorded for the reaction between HOBr and the fully deprotonated resorcinol (k = 2.1 × 10(9) M(-1) s(-1)). The reactivity of phenolic compounds is enhanced by the activating character of the phenolic substituents, e.g. further hydroxyl groups. With the data set from this study, the ratio between the species-specific rate constants for the reactions of chlorine versus bromine with phenolic compounds was confirmed to be about 3000. Phenolic compounds react with bromine or chlorine either by oxidation (electron transfer, ET) or electrophilic aromatic substitution (EAS) processes. The dominant process mainly depends on the relative position of the hydroxyl substituents and the possibility of quinone formation. While phenol, p-hydroxybenzoic acid and bisphenol A undergo EAS, hydroquinone, catechol, gallic acid and tannic acid, with hydroxyl substituents in ortho or para positions, react with bromine by ET leading to quantitative formation of the corresponding quinones. Some compounds (e.g. phloroglucinol) show both partial oxidation and partial electrophilic aromatic substitution and the ratio observed for the pathways depends on the pH. For the reaction of six NOM extracts with bromine, electrophilic aromatic substitution

  1. Assessing the persistence, bioaccumulation potential and toxicity of brominated flame retardants: data availability and quality for 36 alternative brominated flame retardants.

    Science.gov (United States)

    Stieger, Greta; Scheringer, Martin; Ng, Carla A; Hungerbühler, Konrad

    2014-12-01

    Polybrominated diphenylethers (PBDEs) and hexabromocyclododecane (HBCDD) are major brominated flame retardants (BFRs) that are now banned or under restrictions in many countries because of their persistence, bioaccumulation potential and toxicity (PBT properties). However, there is a wide range of alternative BFRs, such as decabromodiphenyl ethane and tribromophenol, that are increasingly used as replacements, but which may possess similar hazardous properties. This necessitates hazard and risk assessments of these compounds. For a set of 36 alternative BFRs, we searched 25 databases for chemical property data that are needed as input for a PBT assessment. These properties are degradation half-life, bioconcentration factor (BCF), octanol-water partition coefficient (Kow), and toxic effect concentrations in aquatic organisms. For 17 of the 36 substances, no data at all were found for these properties. Too few persistence data were available to even assess the quality of these data in a systematic way. The available data for Kow and toxicity show surprisingly high variability, which makes it difficult to identify the most reliable values. We propose methods for systematic evaluations of PBT-related chemical property data that should be performed before data are included in publicly available databases. Using these methods, we evaluated the data for Kow and toxicity in more detail and identified several inaccurate values. For most of the 36 alternative BFRs, the amount and the quality of the PBT-related property data need to be improved before reliable hazard and risk assessments of these substances can be performed.

  2. Bromine release during Plinian eruptions along the Central American Volcanic Arc

    Science.gov (United States)

    Hansteen, T. H.; Kutterolf, S.; Appel, K.; Freundt, A.; Perez-Fernandez, W.; Wehrmann, H.

    2010-12-01

    Volcanoes of the Central American Volcanic Arc (CAVA) have produced at least 72 highly explosive eruptions within the last 200 ka. The eruption columns of all these “Plinian” eruptions reached well into the stratosphere such that their released volatiles may have influenced atmospheric chemistry and climate. While previous research has focussed on the sulfur and chlorine emissions during such large eruptions, we here present measurements of the heavy halogen bromine by means of synchrotron radiation induced micro-XRF microanalysis (SR-XRF) with typical detection limits at 0.3 ppm (in Fe rich standard basalt ML3B glass). Spot analyses of pre-eruptive glass inclusions trapped in minerals formed in magma reservoirs were compared with those in matrix glasses of the tephras, which represent the post-eruptive, degassed concentrations. The concentration difference between inclusions and matrix glasses, multiplied by erupted magma mass determined by extensive field mapping, yields estimates of the degassed mass of bromine. Br is probably hundreds of times more effective in destroying ozone than Cl, and can accumulate in the stratosphere over significant time scales. Melt inclusions representing deposits of 22 large eruptions along the CAVA have Br contents between 0.5 and 13 ppm. Br concentrations in matrix glasses are nearly constant at 0.4 to 1.5 ppm. However, Br concentrations and Cl/Br ratios vary along the CAVA. The highest values of Br contents (>8 ppm) and lowest Cl/Br ratios (170 to 600) in melt inclusions occur across central Nicaragua and southern El Salvador, and correlate with bulk-rock compositions of high Ba/La > 85 as well as low La/Yb discharged 700 kilotons of Br. On average, each of the remaining 21 CAVA eruptions studied have discharged c.100 kilotons of bromine. During the past 200 ka, CAVA volcanoes have emitted a cumulative mass of 3.2 Mt of Br through highly explosive eruptions. There are six periods in the past (c. 2ka, 6ka, 25ka, 40ka, 60ka, 75

  3. Investigating the lifetime of bromine-quenched G.M. Counters with temperature

    Energy Technology Data Exchange (ETDEWEB)

    Abilama, Marc [Centronic Ltd., Croydon (United Kingdom); University of Surrey, Guildford (United Kingdom); Bates, Mike [Centronic Ltd., Croydon (United Kingdom); Lohstroh, Annika [University of Surrey, Guildford (United Kingdom)

    2015-09-21

    The amount of halogen quench gas as a percentage of the total fill gas contained within a gas-filled Geiger–Müller detector is directly linked to its operational characteristics. Preserving this halogen gas will help maintain the operating lifetime of the detectors. Such halogen gases are highly corrosive and the small quantities within a gas-filled detector can deplete rapidly via interactions with surrounding materials. The rate of interactions is thought to be proportional to not only temperature, but also to the current initiated by ionisation events associated with the formation of each signal pulse. As all pulses are of similar magnitudes, GM detector operational lifetimes are quantified in accumulated counts rather than a given operating time. We have studied three different types of corrosion-resistant mechanisms to protect the bromine halogen gas from any interactions with 446 stainless steel detector components of ZP1200 Geiger–Müller tubes at temperatures up to 125 °C. Three types of surface treatments for these detectors used were labelled as “raw” using only an oxygen-plasma-bombardment process, “passivated” using a combination of nitric acid passivation followed by an oxygen plasma-bombardment process, and thirdly plating with a few micron thickness of chromium followed by an oxygen plasma-bombardment process. 32 detector samples were irradiated at room temperature with a Caesium-137 source at dose rates of approximately 1.3 mSv/hr up to 5.7×10{sup 10} accumulated counts; another 32 detector samples were aged to 3.3×10{sup 10} counts at 125 °C. At room temperature, the chromium-plated samples exhibited an initial rise in their starting voltage readings. All other detector performance characteristics, for all detector types, did not change significantly during the ageing process, and the surface morphology of the detector cathodes was unaffected. At 125 °C, the chromium-based plating produced the most stable long-term response. These

  4. Mercury oxidation from bromine chemistry in the free troposphere over the southeastern US

    Directory of Open Access Journals (Sweden)

    S. Coburn

    2015-10-01

    Full Text Available The elevated deposition of atmospheric mercury over the Southeastern United States is currently not well understood. Here we measure partial columns and vertical profiles of bromine monoxide (BrO radicals, a key component of mercury oxidation chemistry, to better understand the processes and altitudes at which mercury is being oxidized in the atmosphere. We use the data from a ground-based MAX-DOAS instrument located at a coastal site ~ 1 km from the Gulf of Mexico in Gulf Breeze, FL, where we had previously detected tropospheric BrO (Coburn et al., 2011. Our profile retrieval assimilates information about stratospheric BrO from the WACCM chemical transport model, and uses only measurements at moderately low solar zenith angles (SZA to estimate the BrO slant column density contained in the reference spectrum (SCDRef. The approach has 2.6 degrees of freedom, and avoids spectroscopic complications that arise at high SZA; knowledge about SCDRef helps to maximize sensitivity in the free troposphere (FT. A cloud-free case study day with low aerosol load (9 April 2010 provided optimal conditions for distinguishing marine boundary layer (MBL: 0–1 km and free tropospheric (FT: 1–15 km BrO from the ground. The average daytime tropospheric BrO vertical column density (VCD of ~ 2.3 × 1013 molec cm−2 (SZA 5 molec cm−2 s−1 for bromine, while contributions from ozone (O3 and chlorine (Cl were 0.9 × 105 and 0.2 × 105 molec cm−2 s−1, respectively. The GOM formation rate is sensitive to recently proposed atmospheric scavenging reactions of the HgBr adduct by nitrogen dioxide (NO2, and to a lesser extent also HO2 radicals. Using a 3-D chemical transport model, we find that surface GOM variations are typical also of other days, and are mainly derived from the free troposphere. Bromine chemistry is active in the FT over Gulf Breeze, where it forms water-soluble GOM that is subsequently available for wet scavenging by thunderstorms or transport to

  5. Seasonal variation of bromine monoxide over the Rann of Kutch salt marsh seen from space

    Science.gov (United States)

    Hörmann, Christoph; Beirle, Steffen; Penning de Vries, Marloes; Sihler, Holger; Platt, Ulrich; Wagner, Thomas

    2015-04-01

    Bromine monoxide (BrO) is an important catalyst in the depletion of tropospheric and stratospheric ozone (O3). In the troposphere, reactive bromine can be released from sea ice, volcanoes, sea-salt aerosol or salt lakes. For all of these natural sources enhanced BrO vertical column densities (VCDs) have been successfully observed from ground using Differential Optical Absorption Spectroscopy (DOAS). Until now, satellite observations were only reported for polar regions during springtime and volcanic emissions (mostly for major eruptions). We present the first satellite observations of enhanced monthly mean BrO VCDs over a salt marsh, the Rann of Kutch (India/Pakistan), during 2004-2014 as seen by the Ozone Monitoring Instrument (OMI). The Rann of Kutch is a so-called 'seasonal' salt marsh. During India's summer monsoon (June/July - September/October), the flat desert of salty clay and mudflats, which average 15 meters above sea level, fills with standing rain and sea water. With more than 7500 km2 it is the largest salt desert in the world and additionally one of the hottest areas of India with summer temperatures around 50 ° C and winter temperatures decreasing below 0 ° C. Probably due to these rather extreme conditions, the Rann of Kutch has not been yet investigated for atmospheric composition measurements by ground-based instruments. Satellite observations, however, provide the unique possibility to investigate the entire area remotely over a long-time period. The OMI data reveals recurring maximum BrO VCDs during April/May, but no enhanced column densities during the monsoon season while the area is flooded. In the following months the signal only recovers slowly while the salty surface dries up. We discuss the possible effects of temperature, precipitation and relative humidity on the release of enhanced reactive bromine concentrations. In order to investigate a possible diurnal cycle of the BrO concentration, the OMI results (at a local overflight time

  6. Structure and cytotoxic activity of sesquiterpene glycoside esters from Calendula officinalis L.: Studies on the conformation of viridiflorol.

    Science.gov (United States)

    D'Ambrosio, Michele; Ciocarlan, Alexandru; Colombo, Elisa; Guerriero, Antonio; Pizza, Cosimo; Sangiovanni, Enrico; Dell'Agli, Mario

    2015-09-01

    Topic applications of Calendula officinalis L. lipophilic extracts are used in phytotherapy to relieve skin inflammatory conditions whereas infusions are used as a remedy for gastric complaints. Such a different usage might be explained by some cytotoxicity of lipophilic extracts at gastric level but little is known about this. Therefore, we screened the CH2Cl2 extract from the flowers of C. officinalis by MTT and LDH assays in human epithelial gastric cells AGS. This bioassay-oriented approach led to the isolation of several sesquiterpene glycosides which were structurally characterized by spectroscopic measurements, chemical reactions and MM calculations. The conformational preferences of viridiflorol fucoside were established and a previously assigned stereochemistry was revised. The compounds 1a, 2a and 3f showed comparably high cytotoxicity in the MTT assays, whereas the effect on LDH release was lower. Our study provides new insights on the composition of C. officinalis extracts of medium polarity and identifies the main compounds that could be responsible for cytotoxic effects at gastric level.

  7. Quantitative HPLC analysis of sesquiterpene lactones and determination of chemotypes in Eremanthus seidelii MacLeish and Schumacher (Asteraceae)

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, Humberto T. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Quimica; Gobbo-Neto, Leonardo; Lopes, Norberto P.; Lopes, Joao L.C. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Fisica e Quimica]. E-mail: joaoluis@usp.br; npelopes@fcfrp.usp.br; Cavalheiro, Alberto J. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica

    2005-11-15

    anthus seidelii MacLeish and Schumacher has a restricted occurrence to the Brazilian 'cerrado' surrounding the Furnas (MG) reservoir, in environments that have been seriously damaged by human activity. The present phytochemical investigation reveals that the sesquiterpene lactones (SL) 4{beta},5-dihydro-2',3'-dihydroxy-15-desoxy-goyazensolide (1) and 4{beta},5-dihydro-1',2'-epoxy-eremantholide-C (2) are the major secondary metabolites in E. seidelii leaves, and an HPLC method was developed for their quantitative analysis. HPLC analysis showed no significant seasonal variation in the concentrations of both SL. No qualitative differences were found in the SL patterns of all individuals sampled. However, there is a different SL quantitative pattern among the plants analyzed, pointing to the existence of three quantitative chemotypes of this species, with differences possibly originating from the activity of the enzymes that cyclize the goyazensolide type SL (1) to a eremantholide type SL (2). (author)

  8. Air-snowpack exchange of bromine, ozone and mercury in the springtime Arctic simulated by the 1-D model PHANTAS – Part 1: In-snow bromine activation and its impact on ozone

    Directory of Open Access Journals (Sweden)

    K. Toyota

    2013-08-01

    Full Text Available To provide a theoretical framework towards better understanding of ozone depletion events (ODEs and atmospheric mercury depletion events (AMDEs in the polar boundary layer, we have developed a one-dimensional model that simulates multiphase chemistry and transport of trace constituents from porous snowpack and through the atmospheric boundary layer (ABL as a unified system. In this paper, we describe a general configuration of the model and the results of simulations related to reactive bromine release from the snowpack and ODEs during the Arctic spring. The model employs a chemical mechanism adapted from the one previously used for the simulation of multiphase halogen chemistry involving deliquesced sea-salt aerosols in the marine boundary layer. A common set of aqueous-phase reactions describe chemistry both in the liquid-like (or brine layer on the grain surface of the snowpack and in "haze" aerosols mainly composed of sulfate in the atmosphere. The process of highly soluble/reactive trace gases, whether entering the snowpack from the atmosphere or formed via gas-phase chemistry in the snowpack interstitial air (SIA, is simulated by the uptake on brine-covered snow grains and subsequent reactions in the aqueous phase while being traveled vertically within the SIA. A "bromine explosion", by which, in a conventional definition, HOBr formed in the ambient air is deposited and then converted heterogeneously to Br2, is a dominant process of reactive bromine formation in the top 1 mm (or less layer of the snowpack. Deeper in the snowpack, HOBr formed within the SIA leads to an in-snow bromine explosion, but a significant fraction of Br2 is also produced via aqueous radical chemistry in the brine on the surface of the snow grains. These top- and deeper-layer productions of Br2 both contribute to the Br2 release into the atmosphere, but the deeper-layer production is found to be more important for the net outflux of reactive bromine. Although ozone

  9. Air-snowpack exchange of bromine, ozone and mercury in the springtime Arctic simulated by the 1-D model PHANTAS - Part 1: In-snow bromine activation and its impact on ozone

    Science.gov (United States)

    Toyota, K.; McConnell, J. C.; Staebler, R. M.; Dastoor, A. P.

    2014-04-01

    To provide a theoretical framework towards a better understanding of ozone depletion events (ODEs) and atmospheric mercury depletion events (AMDEs) in the polar boundary layer, we have developed a one-dimensional model that simulates multiphase chemistry and transport of trace constituents from porous snowpack and through the atmospheric boundary layer (ABL) as a unified system. This paper constitutes Part 1 of the study, describing a general configuration of the model and the results of simulations related to reactive bromine release from the snowpack and ODEs during the Arctic spring. A common set of aqueous-phase reactions describes chemistry both within the liquid-like layer (LLL) on the grain surface of the snowpack and within deliquesced "haze" aerosols mainly composed of sulfate in the atmosphere. Gas-phase reactions are also represented by the same mechanism in the atmosphere and in the snowpack interstitial air (SIA). Consequently, the model attains the capacity of simulating interactions between chemistry and mass transfer that become particularly intricate near the interface between the atmosphere and the snowpack. In the SIA, reactive uptake on LLL-coated snow grains and vertical mass transfer act simultaneously on gaseous HOBr, a fraction of which enters from the atmosphere while another fraction is formed via gas-phase chemistry in the SIA itself. A "bromine explosion", by which HOBr formed in the ambient air is deposited and then converted heterogeneously to Br2, is found to be a dominant process of reactive bromine formation in the top 1 mm layer of the snowpack. Deeper in the snowpack, HOBr formed within the SIA leads to an in-snow bromine explosion, but a significant fraction of Br2 is also produced via aqueous radical chemistry in the LLL on the surface of the snow grains. These top- and deeper-layer productions of Br2 both contribute to the release of Br2 to the atmosphere, but the deeper-layer production is found to be more important for the

  10. Responses of marine unicellular algae to brominated organic compounds in six growth media

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, G.E.; Yoder, M.J.; McLaughlin, L.L.; Lores, E.M.

    1987-12-01

    Marine unicellular algae, Skeletonema costatum, Thalassiosira pseudonana, and Chlorella sp. were exposed to the industrial brominated compounds tetrabromobisphenol A, decabromobiphenyloxide (DBBO), hexabromocyclododecane (HBCD), pentabromomethylbenzene (PBMB), pentabromoethylbenzene (PBEB), and the herbicide bromoxynil (BROM), in six algal growth media. High concentrations of DBBO (1 mg liter-1), PBMB (1 mg liter-1), and PBEB (0.5 mg liter-1) reduced growth by less than 50%. EC50s of the other compounds varied with growth medium, with high EC50/low EC50 ratios between 1.3 and 9.9. Lowest EC50s, 9.3 to 12.0 micrograms liter-1, were obtained with S. costatum and HBCD. It is concluded that responses to toxicants in different media are the results of interactions among algae, growth medium, toxicant, and solvent carrier.

  11. Thinning of CIGS solar cells: Part I: Chemical processing in acidic bromine solutions

    Energy Technology Data Exchange (ETDEWEB)

    Bouttemy, M.; Tran-Van, P. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Gerard, I., E-mail: gerard@chimie.uvsq.fr [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Hildebrandt, T.; Causier, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France); Pelouard, J.L.; Dagher, G. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Jehl, Z.; Naghavi, N. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Voorwinden, G.; Dimmler, B. [Wuerth Elektronik Research GmbH, Industriestr. 4, 70565 Stuttgart (Germany); Powalla, M. [Zentrum fuer Sonnenenergie- und Wasserstoff-Forschung (ZSW), Industriestr. 6, 70565 Stuttgart (Germany); Guillemoles, J.F. [Institut de Recherche et Developpement sur l' Energie Photovoltaique (IRDEP -UMR 7174 CNRS/EDF/Chimie-ParisTech), 6 quai Watier, 78401 Chatou (France); Lincot, D. [Laboratoire de Photonique et de Nanostructures (LPN-CNRS), route de Nozay 91460 Marcoussis (France); Etcheberry, A. [Institut Lavoisier de Versailles (ILV-UMR 8180 CNRS/UVSQ), 45 av. des Etats Unis, 78035 Versailles (France)

    2011-08-31

    CIGSe absorber was etched in HBr/Br{sub 2}/H{sub 2}O to prepare defined thicknesses of CIGSe between 2.7 and 0.5 {mu}m. We established a reproducible method of reducing the absorber thickness via chemical etching. We determine the dissolution kinetics rate of CIGSe using trace analysis by graphite furnace atomic absorption spectrometry of Ga and Cu. The roughness of the etching surface decreases during the first 500 nm of the etching to a steady state value of the root-mean-square roughness near 50 nm. X-ray photoelectron spectroscopy analyses demonstrate an etching process occurring with a constant chemical composition of the treated surface acidic bromine solutions provide a controlled chemical thinning process resulting in an almost flat surface and a very low superficial Se{sup 0} enrichment.

  12. Short-lived brominated hydrocarbons – observations in the source regions and the tropical tropopause layer

    Directory of Open Access Journals (Sweden)

    S. Brinckmann

    2012-02-01

    Full Text Available We conducted measurements of the five important short-lived organic bromine species in the marine boundary layer (MBL. Measurements were made in the Northern Hemisphere mid-latitudes (Sylt Island, North Sea in June 2009 and in the tropical Western Pacific during the TransBrom ship campaign in October 2009. For the one-week time series on Sylt Island, mean mixing ratios of CHBr3, CH2Br2, CHBr2Cl and CH2BrCl were 2.0, 1.1, 0.2, 0.1 ppt, respectively. We found maxima of 5.8 and 1.6 ppt for the two main components CHBr3 and CH2Br2. Along the cruise track in the Western Pacific (between 41° N and 13° S we measured mean mixing ratios of 0.9, 0.9, 0.2, 0.1 and 0.1 ppt for CHBr3, CH2Br2, CHBrCl2, CHBr2Cl and CH2BrCl. Air samples with coastal influence showed considerably higher mixing ratios than the samples with open ocean origin. Correlation analyses of the two data sets yielded strong linear relationships between the mixing ratios of four of the five species (except for CH2BrCl. Using a combined data set from the two campaigns and a comparison with the results from two former studies, rough estimates of the molar emission ratios between the correlated substances were: 9/1/0.35/0.35 for CHBr3/CH2Br2/CHBrCl2/CHBr2Cl. Additional measurements were made in the tropical tropopause layer (TTL above Teresina (Brazil, 5° S in June 2008, using balloon-borne cryogenic whole air sampling technique. Near the level of zero clear-sky net radiative heating (LZRH at 14.8 km about 2.25 ppt organic bromine was bound to the five short-lived species, making up 13% of total organic bromine (17.82 ppt. CH2Br2 (1.45 ppt and CHBr3 (0.56 ppt accounted for 90% of the budget of short-lived compounds in that region. Near the

  13. Surface-confined 2D polymerization of a brominated copper-tetraphenylporphyrin on Au(111)

    CERN Document Server

    Smykalla, Lars; Korb, Marcus; Lang, Heinrich; Hietschold, Michael

    2015-01-01

    A coupling-limited approach for the Ullmann reaction-like on-surface synthesis of a two-dimensional covalent organic network starting from a halogenated metallo-porphyrin is demonstrated. Copper-octabromo-tetraphenylporphyrin molecules can diffuse and self-assemble when adsorbed on the inert Au(111) surface. Splitting-off of bromine atoms bonded at the macrocyclic core of the porphyrin starts at room temperature after the deposition and is monitored by X-ray photoelectron spectroscopy for different annealing steps. Direct coupling between the reactive carbon sites of the molecules is, however, hindered by the molecular shape. This leads initially to an ordered non-covalently interconnected supramolecular structure. Further heating to 300{\\deg}C and an additional hydrogen dissociation step is required to link the molecular macrocycles via a phenyl group and form large ordered polymeric networks. This approach leads to a close-packed covalently bonded network of overall good quality. The structures are characte...

  14. Kinetics and mechanism of the oxidation of some -hydroxy acids by hexamethylenetetramine-bromine

    Indian Academy of Sciences (India)

    Dimple Garg; Seema Kothari

    2004-11-01

    The oxidation of lactic acid, mandelic acid and ten monosubstituted mandelic acids by hexamethylenetetramine-bromine (HABR) in glacial acetic acid, leads to the formation of the corresponding oxoacid. The reaction is first order with respect to each of the hydroxy acids and HABR. It is proposed that HABR itself is the reactive oxidizing species. The oxidation of -deuteriomandelic acid exhibits the presence of a substantial kinetic isotope effect (/ = 5.91 at 298 K). The rates of oxidation of the substituted mandelic acids show excellent correlation with Brown’s + values. The reaction constants are negative. The oxidation exhibits an extensive cross conjugation between the electron-donating substituent and the reaction centre in the transition state. A mechanism involving transfer of a hydride ion from the acid to the oxidant is postulated.

  15. Hydrothermal Synthesis of Mesoporous Nanocrystalline Tetragonal ZrO2 Using Dehydroabietyltrimethyl Ammonium Bromine

    Directory of Open Access Journals (Sweden)

    Peng Wang

    2015-01-01

    Full Text Available Mesoporous nanocrystalline tetragonal zirconias were successfully synthesized through a hydrothermal method using a novel bioresource-derived quaternary ammonium salt, dehydroabietyltrimethyl ammonium bromine (DTAB, as a templating agent. The templating agent provides a surface area (242.02 m2/g, high pore volume (0.53 cm3/g, and large average pore diameter (7.65 nm, which suggests that DTAB is a good candidate for mesostructure synthesis. The hydrothermal treatments give the materials improved thermal stabilities because of the generation of tetragonal nanocrystallites that are more stable than the bulk amorphous ones in the hydrothermal process. However, because of the absence of stabilizers, the sizes of the crystallites of the as-synthesized sample increase gradually with increasing calcination temperature. As the crystalline size of the sample rises to 25 nm, the nanocrystallites become too large to integrate well together, causing the well-organized mesostructure to collapse.

  16. Co-leaching of brominated compounds and antimony from bottled water.

    Science.gov (United States)

    Andra, Syam S; Makris, Konstantinos C; Shine, James P; Lu, Chensheng

    2012-01-01

    A fast-growing bottled water market is occasionally challenged by reports calling for contaminant leaching from water-contact materials (plastics). Our focus was on leaching of antimony (Sb) and brominated compounds expressed by total soluble bromine (Br) measurements, including those of polybrominated diphenyl ethers (PBDE). Studies are lacking on concomitant leaching of two or more inorganic plastic constituents from the same bottle. A market-representative basket survey of bottled water was initiated in Boston, USA supermarkets. Bottled water classes sampled were: i) non-carbonated (NCR), ii) carbonated (CR), and iii) non-carbonated and enriched (NCRE). Plastic bottle materials sampled were: polyethylene terephthalate (PET), high-density polyethylene (HDPE), polystyrene (PS), and polycarbonate (PC). Storage conditions for the 31 bottled water samples were: 23°C temperature, no-shaking and 12h/12h light/dark for 60days of equilibration. Average Br and Sb concentrations after 60-days of storage followed the order of NCR

  17. Meteorological controls on the vertical distribution of bromine monoxide in the lower troposphere

    Directory of Open Access Journals (Sweden)

    P. K. Peterson

    2014-09-01

    Full Text Available Multiple axis differential absorption spectroscopy (MAX-DOAS measurements of bromine monoxide (BrO probed the vertical structure of halogen activation events during March–May 2012 at Barrow, Alaska. An analysis of the BrO averaging kernels and degrees of freedom obtained by optimal-estimation-based inversions from raw MAX-DOAS measurements reveals the information is best represented by reducing the retrieved BrO profile to two quantities, the integrated column from the surface through 200 m (VCD200 m, and the lower tropospheric vertical column density (LT-VCD which represents the integrated column of BrO from the surface through 2 km. The percentage of lower-tropospheric BrO in the lowest 200 m was found to be highly variable ranging from shallow layer events, where BrO is present primarily in the lowest 200 m to distributed column events where BrO is observed at higher altitudes. The highest observed LT-VCD events occurred when BrO was distributed throughout the lower troposphere, rather than concentrated near the surface. Atmospheric stability in the lowest 200 m influenced the percentage of LT-VCD that is in the lowest 200 m, with inverted temperature structures having a first-to-third quartile range (Q1–Q3 of VCD200 m/LT-VCD from 15–39% while near neutral temperature structures had a Q1–Q3 range of 7–13%. Data from this campaign show no clear influence of wind speed on either lower-tropospheric bromine activation (LT-VCD or the vertical distribution of BrO, while examination of seasonal trends and the temperature dependence of the vertical distribution supported the conclusion that the atmospheric stability affects the vertical distribution of BrO.

  18. Scientific Opinion on Emerging and Novel Brominated Flame Retardants (BFRs in Food

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Contaminants in the Food Chain (CONTAM

    2012-10-01

    Full Text Available EFSA was asked to deliver a scientific opinion on brominated flame retardants (BFRs other than PBDEs, PBBs, HBCDDs, TBBPA and brominated phenols and their derivatives. The BFRs that are the subject of the current opinion, were classified in groups termed ‘emerging’ and ‘novel’ BFRs. Information on 17 emerging and 10 novel BFRs was collected. The information varied widely for these BFRs. There is a lack of experimental data on physico-chemical characteristics, stability/reactivity and current use and production volume of all the emerging and novel BFRs. Due to the very limited information on occurrence, exposure and toxicity, the CONTAM Panel could not perform a risk characterisation for any of the BFRs considered. Instead, an attempt was made to identify those BFRs that could be a potential health concern and should be considered first for future investigations. For this purpose the Panel first evaluated the available experimental data on occurrence in food, behaviour in the environment and toxicity. Secondly, a modelling exercise was performed focussing on the potential of the emerging and novel BFRs for persistence in the environment and for their possible bioaccumulation potential. There is convincing evidence that tris(2,3-dibromopropyl phosphate (TDBPP and dibromoneopentyl glycol (DBNPG are genotoxic and carcinogenic, warranting further surveillance of their occurrence in the environment and in food. Based on the limited experimental data on environmental behaviour, 1,2-bis(2,4,6-tribromophenoxyethane (BTBPE and hexabromobenzene (HBB were identified as compounds that could raise a concern for bioaccumulation. For the modelling exercise, the CONTAM Panel selected two environmental characteristics, overall persistence and potential for bioaccumulation, as being most relevant to provide insight into the possibility that emerging or novel BFRs might accumulate in the food chain, and thus might appear in food intended for human

  19. Associations between brominated flame retardants in house dust and hormone levels in men

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Paula I. [Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Stapleton, Heather M. [Nicholas School of the Environment, Box 90328, Duke University, Durham, NC 27708 (United States); Mukherjee, Bhramar [Department of Biostatistics, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 (United States); Hauser, Russ [Department of Environmental Health, Harvard School of Public Health, 677 Huntington Ave., Boston, MA 02115 (United States); Meeker, John D., E-mail: meekerj@umich.edu [Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109 (United States)

    2013-02-15

    Brominated flame retardants (BFRs) are used in the manufacture of a variety of materials and consumer products in order to meet fire safety standards. BFRs may persist in the environment and have been detected in wildlife, humans and indoor dust and air. Some BFRs have demonstrated endocrine and reproductive effects in animals, but human studies are limited. In this exploratory study, we measured serum hormone levels and flame retardant concentrations [31 polybrominated diphenyl ether (PBDE) congeners and 6 alternate flame retardants] in house dust from men recruited through a US infertility clinic. PBDE congeners in dust were grouped by commercial mixtures (i.e. penta-, octa- and deca-BDE). In multivariable linear regression models adjusted by age and body mass index (BMI), significant positive associations were found between house dust concentrations of pentaBDEs and serum levels of free T4, total T3, estradiol, and sex hormone binding globulin (SHBG), along with an inverse association with follicle stimulating hormone (FSH). There were also positive associations of octaBDE concentrations with serum free T4, thyroid stimulating hormone (TSH), luteinizing hormone (LH) and testosterone and an inverse association of decaBDE concentrations with testosterone. Hexabromocyclododecane (HBCD) was associated with decreased SHBG and increased free androgen index. Dust concentrations of bis-tribromophenoxyethane (BTBPE) and tetrabromo-diethylhexylphthalate (TBPH) were positively associated with total T3. These findings are consistent with our previous report of associations between PBDEs (BDE 47, 99 and 100) in house dust and hormone levels in men, and further suggest that exposure to contaminants in indoor dust may be leading to endocrine disruption in men. - Highlights: ► Brominated flame retardants (BFRs) including PBDEs and alternates were measured. ► Exposure to BFRs is characterized from concentrations in participant vacuum bag dust. ► Exposure to PBDEs and

  20. UTILIZATION OF BROMINATION REACTION FOR THE SPECTROPHOTOMETRIC ASSAY OF DOMPERIDONE IN PHARMACEUTICALS

    Directory of Open Access Journals (Sweden)

    O. ZENITA DEVI

    2011-03-01

    Full Text Available Three simple and sensitive spectrophotometric methods are described for the determination of domperidone (DOM in bulk drug and in dosage forms using bromate-bromide mixture as brominating agent in acid medium and three dyes, meta-cresol purple (MCP, amaranth (AMR and erioglaucine (EGC. The methods involve the addition of a known excess of bromate-bromide mixture to an acidified solution of DOM followed by the determination of the residual bromine by reacting with a fixed amount of either MCP dye and measuring the absorbance at 530 nm (method A or AMR dye and measuring the absorbance at 520 nm (method B or EGC dye and measuring the absorbance at 630 nm (method C. Beer’s law is obeyed over the concentration ranges, 0.63–10.0, 0.25-4.0 and 0.13-2.0 µg mL-1 for method A, B and C, respectively. The ap¬parent molar absorptivities are calculated to be 3.751x104, 6.604x104 and 1.987x105 L mol-1cm-1 for method A, B and C, respectively, and the corresponding sandell sensitivity values are 0.011, 0.006 and 0.002 μg cm-2. The limit of detection and the limit of quantification are also reported for all the three methods. No interference was observed from common additives found in pharmaceutical preparations. Statistical comparisons of the results with those of the reference method showed excellent agreement, and indicated no significant difference in accuracy and precision. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standardaddition technique.

  1. Brominated flame retardants in children's toys: concentration, composition, and children's exposure and risk assessment.

    Science.gov (United States)

    Chen, She-Jun; Ma, Yun-Juan; Wang, Jing; Chen, Da; Luo, Xiao-Jun; Mai, Bi-Xian

    2009-06-01

    Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs), 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), decabromodiphenyl ethane (DBDPE), and polybrominated biphenyls (PBBs) were found in children's toys purchased from South China. The median BFR concentrations in the hard plastic toys were 53,000, 5540 ng/g, 101.1 ng/g, and 27.9 ng/g, fortotal PBDEs, DBDPE, BTBPE, and PBBs, respectively,which were notably higher than values in other toys. The PBDE concentrations were below the threshold limit (1000 ppm) required bythe European Commission's Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronic Equipment (WEEE) directives in all of the toys, except for one hard plastic toy with a total PBDE concentration of 5,344,000 ng/g. The BFR profiles in the toys were consistent with the patterns of their current production and consumption in China, where PBDEs, specifically decaBDE product, were the dominant BFR, followed by the emerging DBDPE. The relatively high concentrations of octa- and nonaBDEs in the foam toys and the results of principal component analysis (PCA) may suggest the decomposition of highly brominated BDEs during the manufacturing processes of the toys. Daily total PBDE exposures associated with toys via inhalation, mouthing, dermal contact, and oral ingestion ranged from 82.6 to 8992 pg/kg bw-day for children of 3 months to 14 years of age. Higher exposures, predominantly contributed through the mouthing pathway, were observed for infants and toddlers than for the other subgroups. In most cases, children's BFR exposure via the toys likely accounts for a small proportion of their daily BFR exposure, and the hazard quotients for noncancer risk evaluation were far below 1. To the author's knowledge, this is the first study to examine the concentrations of BFRs in toys, and the potential exposures to children.

  2. Slow Phospholipid Exchange between a Detergent-Solubilized Membrane Protein and Lipid-Detergent Mixed Micelles Brominated Phospholipids as Tools to Follow Its Kinetics

    DEFF Research Database (Denmark)

    Montigny, Cédric; Dieudonné, Thibaud; Orlowski, Stéphane

    2017-01-01

    Membrane proteins are largely dependent for their function on the phospholipids present in their immediate environment, and when they are solubilized by detergent for further study, residual phospholipids are critical, too. Here, brominated phosphatidylcholine, a phospholipid which behaves as an ...

  3. Synthesis of 1-Bromo-3-methoxy-4-propoxy-5-iodobenzene-A Novel Efficient Process for the Synthesis of Brominated Aromatic Compound

    Institute of Scientific and Technical Information of China (English)

    Hong Xin SHI; Hui LIN; Gérard MANDVILLE

    2004-01-01

    The reaction of aromatic carboxylic acid with oxalyl chloride gives rise to the corres- ponding acid chloride which without purification is treated with the sodium salt of mercapto- pyridine oxide in the presence of 2,2-azo-bisisobutyronitrile (AIBN), radical initiator to give a brominated aromatic compound. After etherification and oxidation, 5-iodovaniline was converted to trisubstituted benzene carboxylic acid which give 1-bromo-3-methoxy-4-propoxy-5-iodo- benzene by this new brominating process with a yield of 74 %.

  4. trans-Caryophyllene, a Natural Sesquiterpene, Causes Tracheal Smooth Muscle Relaxation through Blockade of Voltage-Dependent Ca2+ Channels

    Directory of Open Access Journals (Sweden)

    Jader Santos Cruz

    2012-10-01

    Full Text Available trans-Caryophyllene is a major component in the essential oils of various species of medicinal plants used in popular medicine in Brazil. It belongs to the chemical class of the sesquiterpenes and has been the subject of a number of studies. Here, we evaluated the effects of this compound in airway smooth muscle. The biological activities of trans-caryophyllene were examined in isolated bath organs to investigate the effect in basal tonus. Electromechanical and pharmacomechanical couplings were evaluated through the responses to K+ depolarization and exposure to acetylcholine (ACh, respectively. Isolated cells of rat tracheal smooth muscle were used to investigate trans-caryophyllene effects on voltage-dependent Ca2+ channels by using the whole-cell voltage-clamp configuration of the patch-clamp technique. trans-Caryophyllene showed more efficiency in the blockade of electromechanical excitation-contraction coupling while it has only minor inhibitory effect on pharmacomechanical coupling. Epithelium removal does not modify tracheal smooth muscle response elicited by trans-caryophyllene in the pharmacomechanical coupling. Under Ca2+-free conditions, pre-exposure to trans-caryophyllene did not reduce the contraction induced by ACh in isolated rat tracheal smooth muscle, regardless of the presence of intact epithelium. In the whole-cell configuration, trans-caryophyllene (3 mM, inhibited the inward Ba2+ current (IBa to approximately 50% of control levels. Altogether, our results demonstrate that trans-caryophyllene has anti-spasmodic activity on rat tracheal smooth muscle which could be explained, at least in part, by the voltage-dependent Ca2+ channels blockade.

  5. New insights into the parametrization of temperature and light responses of mono - and sesquiterpene emissions from Aleppo pine and rosemary

    Science.gov (United States)

    Staudt, M.; Bourgeois, I.; Al Halabi, R.; Song, W.; Williams, J.

    2017-03-01

    Phytogenic emission of large volatile organic compounds (VOCs) such as monoterpenes (MTs) and sesquiterpenes (SQTs) are key precursors to the formation and growth of atmospheric particles. However, controlled environment studies to elucidate emission responses to temperature and light are still sparse. In this study, the volatile contents and emission responses of Aleppo pine and Rosemary have been investigated. These two common Mediterranean species store semivolatiles inside (resin ducts) and outside (trichomes) their foliage tissues respectively. Both species emitted mainly MTs with basal emission rates of around 5 (Rosemary) and 10 (pine) μg g-1 h-1 and SQTs about one order of magnitude lower. In Aleppo pine, two volatile sources could be clearly distinguished: 1) de-novo synthesized emission of (E)-β-ocimene and linalool, which accounted for about 70% of the total VOC release, were not found in foliar VOC extracts and expressed light dependency (LD) and temperature responses typical for enzyme driven emissions; and 2) storage-derived emissions of various MTs and SQTs whose emissions increased exponentially with temperature, showed no light dependency and were all present in leaf extracts. In Rosemary, all emitted MTs and SQTs including many oxygenated compounds, showed responses typical for stored volatiles and were all found in leaf extracts. The emissions of individual volatiles or volatile classes could be well described with the commonly applied empirical algorithms developed for LD or non LD emissions. However, the shapes of the temperature responses, and hence the deduced coefficient values, were significantly different between oxygenated and non-oxygenated compounds. They also differed between the storage-derived emissions of the two plant species, for individual VOCs or VOC classes. We address the possible reasons for this variation in temperature responses and argue that they are mostly due to molecular interactions along the species specific leaf

  6. Genome mining in Streptomyces avermitilis: cloning and characterization of SAV_76, the synthase for a new sesquiterpene, avermitilol.

    Science.gov (United States)

    Chou, Wayne K W; Fanizza, Immacolata; Uchiyama, Takuma; Komatsu, Mamoru; Ikeda, Haruo; Cane, David E

    2010-07-07

    The terpene synthase encoded by the sav76 gene of Streptomyces avermtilis was expressed in Escherichia coli as an N-terminal-His(6)-tag protein, using a codon-optimized synthetic gene. Incubation of the recombinant protein, SAV_76, with farnesyl diphosphate (1, FPP) in the presence of Mg(2+) gave a new sesquiterpene alcohol avermitilol (2), whose structure and stereochemistry were determined by a combination of (1)H, (13)C, COSY, HMQC, HMBC, and NOESY NMR, along with minor amounts of germacrene A (3), germacrene B (4), and viridiflorol (5). The absolute configuration of 2 was assigned by (1)H NMR analysis of the corresponding (R)- and (S)-Mosher esters. The steady state kinetic parameters were k(cat) 0.040 +/- 0.001 s(-1) and K(m) 1.06 +/- 0.11 microM. Individual incubations of recombinant avermitilol synthase with [1,1-(2)H(2)]FPP (1a), (1S)-[1-(2)H]-FPP (1b), and (1R)-[1-(2)H]-FPP (1c) and NMR analysis of the resulting avermitilols supported a cyclization mechanism involving the loss of H-1(re) to generate the intermediate bicyclogermacrene (7), which then undergoes proton-initiated anti-Markovnikov cyclization and capture of water to generate 2. A copy of the sav76 gene was reintroduced into S. avermitilis SUKA17, a large deletion mutant from which the genes for the major endogenous secondary metabolites had been removed, and expressed under control of the native S. avermitilis promoter rpsJp (sav4925). The resultant transformants generated avermitilol (2) as well as the derived ketone, avermitilone (8), along with small amounts of 3, 4, and 5. The biochemical function of all four terpene synthases found in the S. avermtilis genome have now been determined.

  7. NF-κB p65 repression by the sesquiterpene lactone, Helenalin, contributes to the induction of autophagy cell death

    Directory of Open Access Journals (Sweden)

    Lim Chuan

    2012-07-01

    Full Text Available Abstract Background Numerous studies have demonstrated that autophagy plays a vital role in maintaining cellular homeostasis. Interestingly, several anticancer agents were found to exert their anticancer effects by triggering autophagy. Emerging data suggest that autophagy represents a novel mechanism that can be exploited for therapeutic benefit. Pharmacologically active natural compounds such as those from marine, terrestrial plants and animals represent a promising resource for novel anticancer drugs. There are several prominent examples from the past proving the success of natural products and derivatives exhibiting anticancer activity. Helenalin, a sesquiterpene lactone has been demonstrated to have potent anti-inflammatory and antitumor activity. Albeit previous studies demonstrating helenalin’s multi modal action on cellular proliferative and apoptosis, the mechanisms underlying its action are largely unexplained. Methods To deduce the mechanistic action of helenalin, cancer cells were treated with the drug at various concentrations and time intervals. Using western blot, FACS analysis, overexpression and knockdown studies, cellular signaling pathways were interrogated focusing on apoptosis and autophagy markers. Results We show here that helenalin induces sub-G1 arrest, apoptosis, caspase cleavage and increases the levels of the autophagic markers. Suppression of caspase cleavage by the pan caspase inhibitor, Z-VAD-fmk, suppressed induction of LC3-B and Atg12 and reduced autophagic cell death, indicating caspase activity was essential for autophagic cell death induced by helenalin. Additionally, helenalin suppressed NF-κB p65 expression in a dose and time dependent manner. Exogenous overexpression of p65 was accompanied by reduced levels of cell death whereas siRNA mediated suppression led to augmented levels of caspase cleavage, autophagic cell death markers and increased cell death. Conclusions Taken together, these results show

  8. Seasonal variation in basal emission rates and composition of mono- and sesquiterpenes emitted from dominant conifers in Japan

    Science.gov (United States)

    Matsunaga, Sou N.; Niwa, Shigeru; Mochizuki, Tomoki; Tani, Akira; Kusumoto, Dai; Utsumi, Yasuhiro; Enoki, Tsutomu; Hiura, Tsutom

    2013-04-01

    Biogenic volatile organic compounds (BVOCs) are known to play an important role in atmospheric chemistry due to their high reactivity and high emission rates. Therefore, in recent decades, many efforts have been made to estimate the emission rates, composition and allocation of the BVOCs. Monoterpenes (MNTs) and sesquiterpenes (SQTs) are major groups of BVOCs and mainly emitted from coniferous trees. There is quite a few reports discussing the seasonality of basal emission rate, which is a normalized emission rate at a set of standard conditions (e.g. temperature, light intensity), of the BVOCs. Three field measurements were conducted using branch enclosure techniques to determine MNTs and SQTs emission measured from mature trees of Cryptomeria japonica and Chamaecyparis obtusa, which are the most dominant trees in Japan and account for about 40-50% of Japanese forest in leaf amount throughout the four seasons in southern Japan in 2010. The results are compared with the measurements for the same compound classes obtained at a suburban area of Tokyo, Japan in 2009. The seasonal variation in the basal emissions of MNTs from both tree species at Shiiba did not show significant seasonal changes. For both tree species, the variations in the basal emission of MNTs differ in the two sites, while those of SQTs showed relatively similar variations. Chemical composition of SQTs showed clear and continued seasonal variations, while MNTs did not show any clear seasonal variation for these tree species at both sites. It can be hypothesized that the emissions of BVOC classes (e.g. MNTs and SQTs) depend on leaf age. In this paper, we discuss about the seasonal variations in the basal emission rates and chemical compositions of BVOCs obtained from the two dominant coniferous tree species in Japan based on nine field measurement campaigns conducted at two different sites.

  9. Bioactivity of the extracts and isolation of lignans and a sesquiterpene from the aerial parts of Centaurea pamphylica (Asteraceae

    Directory of Open Access Journals (Sweden)

    Shoeb M.

    2007-06-01

    Full Text Available Centaurea pamphylica Boiss. & Heldr. (Family: Asteraceae, commonly known as ‘pamphylia daisy', is a Turkish endemic species of the genus Centaurea that comprises ca. 500 species, many of which have been used as traditional medicines.  The n-hexane, dichloromethane (DCM and methanol (MeOH extracts of the aerial parts of C. pamphylica were assessed for antioxidant activity and general toxicity using, respectively, the 2,2-diphenyl-1-picrylhydrazyl (DPPH, and the brine shrimp lethality assays. The reversed-phase preparative HPLC and PTLC were used to isolate compounds from the extracts.  The structures of these compounds [1-4] were elucidated by spectroscopic means, and also by direct comparison with the respective published data.  Both the DCM and the MeOH extract showed significant levels of antioxidant activities with the RC50 values of 72.6 x 10-2 and 47.3 ´ 10-2 mg/mL, respectively. The MeOH extract exhibited low levels of toxicity towards brine shrimps (LD50 = 125.0 ´ 10-2 mg/mL. Three major bioactive components of the MeOH extract were matairesinoside [1], arctiin [2] and matairesinol [3]. An eudesmane-type sesquiterpene, pterodontriol [4], was also isolated from the DCM extract.  Since reactive oxygen species are important contributors to various ailments, the antioxidant properties of the extracts as well as the isolated compounds may be of medicinal significance. This is the first report on the occurrence of 1-4 in C. pamphylica, and 4 in the genus Centaurea.  

  10. Biogenic guaianolide-type sesquiterpene lactones with antioxidative and anti-inflammatory properties from natural mangrove hybrid Rhizophora annamalayana.

    Science.gov (United States)

    Raola, Vamshi Krishna; Chakraborty, Kajal

    2017-02-24

    Previously undescribed guaianolide-type sesquiterpene lactones were isolated from the chloroform fraction of the natural hybrid mangrove Rhizophora annamalayana, and were characterised as (Z)-3α,4,5,6-tetrahydro-5α-isobutyl-2β-(methoxymethyl)-7-methyl-3H-cyclohepta[b]carbolactone (1) and (7Z)-isopentyl 3α,4,5,6,7,8-hexahydro-2β-((E)-11-methylbut-10-enyl)-1-oxo-2H-cyclohepta[b]furan-6-carboxylate (2). Compound 2 displayed greater antioxidative activities {1, 1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2'-azino-bis-3 ethylbenzothiozoline-6-sulphonic acid diammonium salt (ABTS), IC50 0.65 and 0.62 mg/mL, respectively)} compared to 1 (IC50 0.83 and 1.14 mg/mL, respectively) (p < 0.05). Compound 2 recorded no significant difference in DPPH(.) scavenging activities (IC50 0.65 mg/mL) compared to α-tocopherol (IC50 0.63 mg/mL). Pro-inflammatory 5-lipoxygenase inhibitory activity of 2 was found to be comparable (IC50 0.98 mg/mL) to that displayed by synthetic anti-inflammatory drug ibuprofen (IC50 0.93 mg/mL). Compound 2 showed significantly greater selectivity index (anti-cyclooxygenase-1/anti-cyclooxygenase-2 = 2.15) than non-steroidal anti-inflammatory ibuprofen (<0.5) (p < 0.05), and therefore, might be used as selective cyclooxygenase-2 inhibitor. The hitherto undescribed guaianolide lactones might be used as potential anti-inflammatory and antioxidative pharmacophore leads.

  11. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in breast milk from Shanghai: implication for exposure route of higher brominated BDEs.

    Science.gov (United States)

    Ma, Shengtao; Yu, Zhiqiang; Zhang, Xiaolan; Ren, Guofa; Peng, Ping'an; Sheng, Guoying; Fu, Jiamo

    2012-07-01

    Breast milk has been widely used as a bioindicator to assess the extent of human exposure to PBDEs via various exposure routes. In this study, 48 breast milk samples were collected from primiparous women in Shanghai city, and 14 PBDEs congeners (BDE-28, -47, -99, -100, -153, -154, -183, -196, -197, -203, -206, -207, -208, and -209) were quantified using gas chromatography-electron capture negative ionization-mass spectrometry. The mean concentration of total PBDEs was 8.6 ng/g lipid weight, and ranged from 1.8 to 26.7 ng/g lipid weight. These concentration levels were similar to those reported in Europe and Asia, but one order of magnitude lower than those in North America. The congener profiles in this study exhibited a specific pattern in human milk found worldwide, BDE-153 and BDE-28 accounted for a relatively higher proportion of lower brominated BDEs (from tri- to hepta-BDEs), whereas higher brominated BDEs (from octa- to deca-BDEs) contributed more than 70% of the total PBDEs. The Spearman's correlation coefficient among higher brominated BDEs showed a positive relationship, and concentration levels of higher brominated BDEs were statistically different between office workers and housewives. Due to relatively higher proportion of PBDEs from octa- to deca-BDEs were detected, air inhalation and dust ingestion might be the major exposure routes of higher brominated BDEs. Further research is needed to clarify the major exposure route of higher brominated BDEs to humans.

  12. High performance liquid chromatography time of flight electrospray ionization mass spectrometry for quantification of sesquiterpenes in Chrysanthemi indici Flos active extract

    Science.gov (United States)

    Fu, Ling; Wang, Pan; Sun, Yiqun; Wang, Yangyang; Zhao, Jing; Ye, Yuting; Zhang, Yanbin; Bi, Yuefeng

    2015-01-01

    Background: Chrysanthemi indici Flos, a traditional herbal medicine is used to clearing heat–toxicity, removing the liver fire, and improving eyesight. In our preliminary work, an active extract of CTC in C. An indici Flos with anti-hepatitis B virus and liver protective activity was found by HepG2.2.1.5 test and experiment of protein synthesis in mice's injured liver. In this work, we aimed to study the active faction CTC further by qualitative and quantitative analysis method. Materials and Methods: High performance liquid chromatography time of flight electrospray ionization mass spectrometry (HPLC TOF ESI-MS) analysis method of the CTC was established. Cumambrin A and angeloylcumambrin B in CTC were analyzed by high performance liquid chromatography-ultraviolet-evaporative light scattering detector (HPLC-UV-ELSD) analysis methods. A binary gradient elution program was conducted for chromatographic separation with acetonitrile (A) and ultrapure water (B) as follows: 0–10 min, 42–46% A; 10–20 min, 46–55% A; 20–25 min, 55–60% A; and 25–35 min, 60–75% A. The column temperature and UV wavelength were set at 30°C and 205 nm. Result: Ten constituents including (3R, 5R, 6S, 7S, 10R)-7-(2-hydroxy-2-propyl)-10-methyl-4-methyleneperhy, dronaphthal-ene-3, 5, 6-triol acetone solvate; (+)-edusmance-4, (14)-ene-11, 13-diol; linarin; luteolin; apigenin; tricin; 5, 3’,4’- trimethyl-6,7-dimethoxy flavones; cumambrin A; acacetin; and angeloylcumambrin B in CTC were identified by HPLC TOF ESI-MS. The contents of sesquiterpenes in CTC were decreased by storing years. Conclusions: The results showed that both UV and ELSD methods were feasible, accurate, and the determination results were in good consistency. The contents of two sesquiterpenes decreased with storing years. Two sesquiterpenes could be used as quality control for C. indici flos CTC. PMID:26600718

  13. Chemistry of recoil atoms of bromine-82 in neutron-irradiated crystalline perbromates of the alkali metals and ammonium

    Energy Technology Data Exchange (ETDEWEB)

    Gavrilov, V.V.; Isupov, V.K.; Kirin, I.S.

    1975-01-01

    It was established by ion exchange chromatography that the recoil atoms of bromine-82 in perbromates with thermal neutrons are stabilized in the form of five valence forms: BrO/sub 4//sup -/, BrO/sub 3//sup -/, BrO/sub 2//sup -/, BrO/sup -/, Br/sup -/. The retention of bromine-82 of BrO/sub 4//sup -/ is 2.1 +- 0.4 percent for LiBrO/sub 4/, 2.1 +- 0.4 percent for NaBrO/sub 4/, 2.3 +- 0.4 percent for KBrO/sub 4/, 2.6 +- 0.4 percent for RbBrO/sub 4/, 2.2 +- 0.4 percent for CsBrO/sub 4/, and 1.6 +- 0.4 percent for NH/sub 4/BrO/sub 4/.

  14. Sesquiterpene lactone containing extracts from two cultivars of forage chicory (Cichorium intybus) show distinctive chemical profiles and in vitro activity against Ostertagia ostertagi

    DEFF Research Database (Denmark)

    Pena-Espinoza, Miguel Angel; Boas, Ulrik; Williams, Andrew;

    2015-01-01

    The study investigated direct anthelmintic effects of sesquiterpene lactones (SL)-containing extracts from forage chicory against free-living and parasitic stages of Ostertagia ostertagi. Freeze-dried leaves from chicory cultivars ‘Spadona’ and ‘Puna II’ were extracted using methanol/water. Total...... SL were further fractionated by solid-phase extraction and resulting extracts were characterised by high-performance liquid chromatography (HPLC). O. ostertagi eggs from faeces of mono-infected calves were hatched and L1 were used in a larval feeding inhibition assay (LFIA), while cultured L3 were...

  15. Shizukaol D, a Dimeric Sesquiterpene Isolated from Chloranthus serratus, Represses the Growth of Human Liver Cancer Cells by Modulating Wnt Signalling Pathway.

    Science.gov (United States)

    Tang, Lisha; Zhu, Hengrui; Yang, Xianmei; Xie, Fang; Peng, Jingtao; Jiang, Deke; Xie, Jun; Qi, Meiyan; Yu, Long

    2016-01-01

    Natural products have become sources of developing new drugs for the treatment of cancer. To seek candidate compounds that inhibit the growth of liver cancer, components of Chloranthus serratus were tested. Here, we report that shizukaol D, a dimeric sesquiterpene from Chloranthus serratus, exerted a growth inhibition effect on liver cancer cells in a dose- and time-dependent manner. We demonstrated that shizukaol D induced cells to undergo apoptosis. More importantly, shizukaol D attenuated Wnt signalling and reduced the expression of endogenous Wnt target genes, which resulted in decreased expression of β-catenin. Collectively, this study demonstrated that shizukaol D inhibited the growth of liver cancer cells by modulating Wnt pathway.

  16. Sesquiterpenes produced by endophytic fungus Phomopsis cassiae with antifungal and acetylcholinesterase inhibition activities; Sesquiterpenos produzidos pelo fungo endofitico Phomopsis cassiae com atividade antifungica e inibidora de acetilcolinesterase

    Energy Technology Data Exchange (ETDEWEB)

    Zanardi, Lisineia M.; Bolzani, Vanderlan da S.; Cavalheiro, Alberto J.; Silva, Dulce H. Siqueira; Trevisan, Henrique C.; Araujo, Angela R. [UNESP, Araraquara, SP (Brazil). Inst. de Quimica; Silva, Geraldo H. [Universidade Federal de Sergipe (UFS), Aracaju, SE (Brazil). Centro de Ciencias Exatas e Tecnologia; Teles, Helder L. [Universidade Federal do Mato Grosso (UFMT), Rondonopolis, MT (Brazil). Dept. de Ciencias Biologicas; Young, Maria Claudia M., E-mail: araujoar@iq.unesp.br [Instituto de Botanica, Sao Paulo, SP (Brazil). Seccao de Fisiologia e Bioquimica de Plantas

    2012-07-01

    Two new diastereoisomeric cadinanes sesquiterpenes 3,9-dihydroxycalamenene (1-2), along with the known 3-hydroxycalamen-8-one (3) and aristelegone-A (4), were isolated from ethyl acetate extract of Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures, including relative stereochemistry, were determined on the basis of detailed interpretation of 2D NMR spectra and comparison with related known compounds. Compounds 1-4 displayed antifungal activity against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as inhibition of acetylcholinesterase. (author)

  17. The mercury species and their association with carbonaceous compositions, bromine and iodine in PM2.5 in Shanghai.

    Science.gov (United States)

    Duan, Lian; Xiu, Guangli; Feng, Ling; Cheng, Na; Wang, Chenggang

    2016-03-01

    PM2.5 samples were collected in south Shanghai from November 2013 to October 2014. The species of particulate bounded mercury (PBM), including hydrochloric soluble particle-phase mercury (HPM), element soluble particle-phase mercury (EPM) and residual soluble particle-phase mercury (RPM), were determined in PM2.5. The chemical composition of PM2.5 including organic carbon (OC) and elemental carbon (EC), total bromine and iodine were also analyzed. The results showed that the annual average concentration of PBM was 0.30 ± 0.31 ng m(-3) and 0.34 ± 0.32 ng m(-3) in winter, 0.31 ± 0.19 ng m(-3) in spring, 0.30 ± 0.45 ng m(-3) in fall and 0.28 ± 0.17 ng m(-3) in summer. HPM took the highest fraction 51.2% in PBM, followed by RPM 27.7% and EPM 21.1%. EC positively correlated to particle mercury, especially in winter (r = 0.70), the same for OC in winter (r = 0.72), which indicated that the carbonaceous composition may affect the transformation of Hg in the atmosphere. Mercury species showed different correlations with bromine and iodine in the four seasons. The strongest correlation between bromine, iodine and mercury was found in spring and fall, respectively. Bromine showed the stronger correlation with total mercury and speciated particle mercury than iodine. In addition, the days were classified into haze and non-haze days based on the visibility and relative humidity, while the ratio of HPM in haze days was much higher than that in non-haze days. EC strongly correlated with PBM during haze and non-haze days while OC only positively correlated with PBM in non-haze days, this may indicate that the different carbonaceous part may affect PBM differently.

  18. Impact of biogenic very short-lived bromine on the Antarctic ozone hole during the 21st century

    OpenAIRE

    Fernandez, Rafael P.; Kinnison, Douglas E.; Lamarque, Jean-Francois; Tilmes, Simone; Saiz-Lopez, Alfonso

    2017-01-01

    Active bromine released from the photochemical decomposition of biogenic very short-lived bromocarbons (VSLBr) enhances stratospheric ozone depletion. Based on a dual set of 1960–2100 coupled chemistry–climate simulations (i.e. with and without VSLBr), we show that the maximum Antarctic ozone hole depletion increases by up to 14 % when natural VSLBr are considered, which is in better agreement with ozone observations. The impact of the additional 5 pptv VSLBr on Antarctic...

  19. Impact of biogenic very short-lived bromine on the Antarctic ozone hole during the 21st century

    OpenAIRE

    Fernandez, Rafael P.; Kinnison, Douglas E.; Lamarque, Jean-Francois; Tilmes, Simone; Saiz-Lopez, Alfonso

    2016-01-01

    Active bromine released from the photochemical decomposition of biogenic very short-lived bromocarbons (VSLBr) enhances stratospheric ozone depletion. Based on a dual set of 1960–2100 coupled chemistry-climate simulations (i.e. with and without VSLBr), we show that the maximum Antarctic ozone hole depletion increases by up to 14 % when natural VSLBr are considered, in better agreement with ozone observations. The impact of the additional 5 pptv VSLBr on Antarctic ozone is ...

  20. Temporal development of brominated flame retardants in peregrine falcon (Falco peregrinus) eggs from South Greenland (1986-2003)

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Thomsen, Marianne; Falk, Knud;

    2005-01-01

    A time trend between 1986 and 2003 was found for brominated flame retardants in peregrine falcon eggs from South Greenland, with significantly increasing concentrations of the polybrominated diphenyl ethers (PBDEs) 99, 100, 153, 154, and 209. For BDE-99 and -100, the concentration increased...... with increasing time trends exist for the BDEs 99, 100, 153, 154, and 209, while a decreasing contamination with the BDEs 183, 49, 47, 66 and 153 was indicated in a subset of eggs....

  1. An Empirical Approach to Determining the Boundary Layer Bromine Monoxide (BrO) Abundance from Satellite Total Column Measurements

    Science.gov (United States)

    Simpson, W. R.; Donohoue, D.; Carlson, D. A.

    2009-12-01

    Unique chemistry in the Arctic boundary layer during springtime liberates bromine from sea salt, producing reactive halogen gases (e.g. atomic bromine and bromine monoxide radicals) that then drastically alter atmospheric oxidation pathways. This phenomenon causes ozone depletion events and affects mercury deposition to the snowpack. Satellite remote sensing (e.g. OMI and GOME2 observations) techniques can detect the total column abundance of BrO, which is generally the primary species of the reactive bromine family. However, BrO is also present in the stratosphere, so it is necessary to partition the satellite-observed BrO column abundance into boundary layer and non-boundary layer (primarily stratospheric) partial columns to be able to infer boundary layer abundances and hence chemical affects near the Earth's surface (i.e. ozone and mercury impacts). In this presentation, we describe an empirical method for partitioning the BrO total column and apply it globally during spring 2008. The method indicates that some BrO total column enhancements ("hotspots") are not actually enhancements in the boundary layer BrO abundance but occur aloft. Movies and a statistical analysis of the inferred boundary layer BrO abundance are presented. The method has been tested and performs well at the Barrow field site. However, in areas that lack routine ground truth BrO measurements (e.g. Hudson Bay, Canada), large tropospheric BrO abundances are indicated. It is not clear if these inferred boundary layer BrO events are real or if the simple empirical method described here is failing in those locations. Verification of this method over large spatial regions of the Arctic is needed.

  2. Utilization of a Green Brominating Agent for the Spectrophotometric Determination of Pipazethate HCl in Pure Form and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ayman A. Gouda

    2013-01-01

    Full Text Available Five simple, accurate, and sensitive spectrophotometric methods (A–E have been described for the indirect assay of pipazethate HCl (PZT either in pure form or in pharmaceutical preparations. The proposed methods are based on the bromination of pipazethate HCl with a solution of excess bromate-bromide mixture in hydrochloric acid medium and subsequent estimation of the residual bromine by different reaction schemes. In the first three methods (A–C, the determination of the residual bromine is based on its ability to bleach the color of methyl orange, indigo carmine, or thymol blue dyes and measuring the absorbance at 520, 610, and 550 nm for methods A, B, and C, respectively. Methods D and E involves treating the unreacted bromine with a measured excess of iron(II, and the remaining iron(II is complexed with 1,10-phenanthroline, and the increase in absorbance is measured at 510 nm for method D and the resulting iron(III is complexed with thiocyanate and the absorbance is measured at 480 nm for method E. The different experimental parameters affecting the development and stability of the color are carefully studied and optimized. Regression analysis of the Beer-Lambert plots showed good correlation in the concentration ranges of 0.5–8.0 μg . The apparent molar absorptivity, Sandell's sensitivity, detection and quantitation limits were evaluated. The proposed methods have been applied and validated successfully for the analysis of the drug in its pure form and pharmaceutical formulations with mean recoveries of 99.94%–100.15% and relative standard deviation ≤1.53. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

  3. [Formation of disinfection by-products by Microcystis aeruginosa intracellular organic matter: comparison between chlorination and bromination].

    Science.gov (United States)

    Tian, Chuan; Guo, Ting-Ting; Liu, Rui-Ping; Jefferson, William; Liu, Hui-Juan; Qu, Jiu-Hui

    2013-11-01

    In order to illustrate the effects of released algal organic matter in cyanobacteria blooms on raw water quality and water treatment process, intracellular organic matter (IOM) of Microcystis aeruginosa, which is the dominant species in cyanobacteria blooms, was chosen as a precursor and characterized. In addition, the transformation of IOM and the formation of disinfection byproducts were evaluated at different pH of 6.5, 7.1 and 8.4 after chlorination or bromination, with subsequent correlation analysis. The results indicated that IOM was primarily composed of macromolecular matter, i. e. , the species with relative molecular weight of > 30 x 10(3), constituting 68.8% of dissolved organic carbon (DOC). Fluorescence excitation-emission matrix indicated that IOM was mainly composed of aromatic protein-like matter with an intensity of 92.6 AU x L x mg(-1). After reaction with chlorine or bromine, the intensity of aromatic protein-like peaks decreased sharply by 76.6% - 93.3%, and its reduction correlated well with the formation of trihalomethane (THMs, R2 = 0.81) and haloacetic acid (HAAs, R2 = 0.77). The formation of THMs and HAAs increased with the increase in pH. Compared with chlorine, bromine formed more THMs and HAAs, and tended to form highly halogenated HAAs. However, with increasing pH, the reactivity with IOM between chlorine and bromine was closer, i.e, k(OBr-IOM)/k(OCl-(IOM) < k(HOBr-IOM/k(HOCl-IOM).

  4. Probing the subtropical lowermost stratosphere and the tropical upper troposphere and tropopause layer for inorganic bromine

    Science.gov (United States)

    Werner, Bodo; Stutz, Jochen; Spolaor, Max; Scalone, Lisa; Raecke, Rasmus; Festa, James; Fedele Colosimo, Santo; Cheung, Ross; Tsai, Catalina; Hossaini, Ryan; Chipperfield, Martyn P.; Taverna, Giorgio S.; Feng, Wuhu; Elkins, James W.; Fahey, David W.; Gao, Ru-Shan; Hintsa, Erik J.; Thornberry, Troy D.; Moore, Free Lee; Navarro, Maria A.; Atlas, Elliot; Daube, Bruce C.; Pittman, Jasna; Wofsy, Steve; Pfeilsticker, Klaus

    2017-01-01

    We report measurements of CH4 (measured in situ by the Harvard University Picarro Cavity Ringdown Spectrometer (HUPCRS) and NOAA Unmanned Aircraft System Chromatograph for Atmospheric Trace Species (UCATS) instruments), O3 (measured in situ by the NOAA dual-beam ultraviolet (UV) photometer), NO2, BrO (remotely detected by spectroscopic UV-visible (UV-vis) limb observations; see the companion paper of Stutz et al., 2016), and of some key brominated source gases in whole-air samples of the Global Hawk Whole Air Sampler (GWAS) instrument within the subtropical lowermost stratosphere (LS) and the tropical upper troposphere (UT) and tropopause layer (TTL). The measurements were performed within the framework of the NASA-ATTREX (National Aeronautics and Space Administration - Airborne Tropical Tropopause Experiment) project from aboard the Global Hawk (GH) during six deployments over the eastern Pacific in early 2013. These measurements are compared with TOMCAT/SLIMCAT (Toulouse Off-line Model of Chemistry And Transport/Single Layer Isentropic Model of Chemistry And Transport) 3-D model simulations, aiming at improvements of our understanding of the bromine budget and photochemistry in the LS, UT, and TTL.Changes in local O3 (and NO2 and BrO) due to transport processes are separated from photochemical processes in intercomparisons of measured and modeled CH4 and O3. After excellent agreement is achieved among measured and simulated CH4 and O3, measured and modeled [NO2] are found to closely agree with ≤ 15 ppt in the TTL (which is the detection limit) and within a typical range of 70 to 170 ppt in the subtropical LS during the daytime. Measured [BrO] ranges between 3 and 9 ppt in the subtropical LS. In the TTL, [BrO] reaches 0.5 ± 0.5 ppt at the bottom (150 hPa/355 K/14 km) and up to about 5 ppt at the top (70 hPa/425 K/18.5 km; see Fueglistaler et al., 2009 for the definition of the TTL used), in overall good agreement with the model simulations. Depending on the

  5. Degradation of Polymeric Brominated Flame Retardants: Development of an Analytical Approach Using PolyFR and UV Irradiation.

    Science.gov (United States)

    Koch, Christoph; Dundua, Alexander; Aragon-Gomez, Jackelyn; Nachev, Milen; Stephan, Susanne; Willach, Sarah; Ulbricht, Mathias; Schmitz, Oliver J; Schmidt, Torsten C; Sures, Bernd

    2016-12-06

    Many well-established methods for studying the degradation of brominated flame retardants are not useful when working with polymeric and water insoluble species. An example for this specific class of flame retardants is PolyFR (polymeric flame retardant; CAS No 1195978-93-8), which is used as a substituent for hexabromocyclododecane. Although it has been on the market for two years now, almost no information is available about its long time behavior in the environment. Within this study, we focus on how to determine a possible degradation of both pure PolyFR as well as PolyFR in the final insulation product, expanded polystyrene foam. Therefore, we chose UV radiation followed by analyses of the total bromine content at different time points via ICP-MS and identified possible degradation products such as 2,4,6-tribromophenol through LC-MS. These results were then linked with measurements of the adsorbable organically bound bromine and total organic carbon in order to estimate their concentrations. With respect to the obtained (1)H NMR, GPC, and contact angle results, the possibility for further degradation was discussed, as UV irradiation can influence the decomposition of molecules in combination with other environmental factors like biodegradation.

  6. Bromination of Graphene: A New Route to Making High Performance Transparent Conducting Electrodes with Low Optical Losses

    KAUST Repository

    Mansour, Ahmed

    2015-07-22

    The unique optical and electrical properties of graphene have triggered great interest in its application as a transparent conducting electrode material and significant effort has been invested in achieving high conductivity while maintaining transparency. Doping of graphene has been a popular route for reducing its sheet resistance, but this has typically come at a significant cost in optical transmission. We demonstrate doping of few layers graphene with bromine as a means of enhancing the conductivity via intercalation without major optical losses. Our results demonstrate the encapsulation of bromine leads to air-stable transparent conducting electrodes with five-fold improvement of sheet resistance reaching at the cost of only 2-3% loss of optical transmission. The remarkably low tradeoff in optical transparency leads to the highest enhancements in the figure of merit reported thus far for FLG. Furthermore, we tune the workfunction by up to 0.3 eV by tuning the bromine content. These results should help pave the way for further development of graphene as a potential substitute to transparent conducting polymers and metal oxides used in optoelectronics, photovoltaics and beyond.

  7. Brominated flame retardants in the surrounding soil of two manufacturing plants in China: Occurrence, composition profiles and spatial distribution.

    Science.gov (United States)

    Li, Wen-Long; Liu, Li-Yan; Zhang, Zi-Feng; Song, Wei-Wei; Huo, Chun-Yan; Qiao, Li-Na; Ma, Wan-Li; Li, Yi-Fan

    2016-06-01

    Surface soil samples were collected surrounding two brominated flame retardants (BFRs) manufacturing plants in China in August 2014 and analyzed for 23 polybrominated diphenyl ethers (PBDEs) and 8 novel brominated flame retardants (NBFRs). BDE209 and decabromodiphenylethane (DBDPE) were the predominant compounds in soil with the median levels of 1600 and 560 ng/g dw, respectively. The PBDEs profiles in soil samples were consistent with that of commercial product (comDecaBDE). The percentage contributions to total PBDEs decreased from higher to lower brominated homologues. Lower concentrations of NBFRs (excluding DBDPE) were detected in soil surrounding the two plants, suggesting they are byproducts or degradation products of the manufacturing activities. The concentrations of most BFRs dropped exponentially within 3-5 km of the manufacturing plants, suggesting recent deposition of these compounds to the soil. Directional distribution indicated that PBDEs and DBDPE concentrations were highest in the north direction of Plants 1. Three-day air parcel forward trajectories confirmed that the air parcel was responsible for the higher concentration of BFRs in the soil of north direction of the plant.

  8. Brominated flame retardants in food and environmental samples from a production area in China: concentrations and human exposure assessment.

    Science.gov (United States)

    Li, Peng; Wu, Hui; Li, Qiuxu; Jin, Jun; Wang, Ying

    2015-11-01

    Human exposure to brominated flame retardants (BFRs: decabromodiphenyl ether (BDE209), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB), pentabromoethylbenzene (PBEB), pentabromotoluene (PBT), 1,2,3,4,5-pentabromobenzene (PBBz), and 2,3,5,6-tetrabromo-p-xylene (TBX)) in a brominated flame retardant production area (Weifang, Shandong Province, China) was estimated. Thirty food samples, 14 air samples, and 13 indoor dust samples were analyzed. BDE209 and DBDPE were the dominant BFRs in all samples. Higher alternative brominated flame retardant (including DBDPE, HBB, PBEB, PBT, PBBz, and TBX) concentrations were found in vegetables than in fish and meat; thus, plant-original foods might be important alternative BFR sources in the study area. The BDE209 and alternative BFR concentrations in air were 1.5×10(4) to 2.2×10(5) and 620 to 3.6×10(4) pg/m3, respectively. Mean total BFR exposures through the diet, inhalation, and indoor dust ingestion were 570, 3000, and 69 ng/d, respectively (16, 82, and 2% of total intake, respectively). Inhalation was the dominant BFR source except for DBDPE, for which diet dominated. BDE209 contributed 85% of the total BFR intake in the study area.

  9. Impact of biogenic very short-lived bromine on the Antarctic ozone hole during the 21st century

    Science.gov (United States)

    Fernandez, Rafael P.; Kinnison, Douglas E.; Lamarque, Jean-Francois; Tilmes, Simone; Saiz-Lopez, Alfonso

    2017-02-01

    Active bromine released from the photochemical decomposition of biogenic very short-lived bromocarbons (VSLBr) enhances stratospheric ozone depletion. Based on a dual set of 1960-2100 coupled chemistry-climate simulations (i.e. with and without VSLBr), we show that the maximum Antarctic ozone hole depletion increases by up to 14 % when natural VSLBr are considered, which is in better agreement with ozone observations. The impact of the additional 5 pptv VSLBr on Antarctic ozone is most evident in the periphery of the ozone hole, producing an expansion of the ozone hole area of ˜ 5 million km2, which is equivalent in magnitude to the recently estimated Antarctic ozone healing due to the implementation of the Montreal Protocol. We find that the inclusion of VSLBr in CAM-Chem (Community Atmosphere Model with Chemistry, version 4.0) does not introduce a significant delay of the modelled ozone return date to 1980 October levels, but instead affects the depth and duration of the simulated ozone hole. Our analysis further shows that total bromine-catalysed ozone destruction in the lower stratosphere surpasses that of chlorine by the year 2070 and indicates that natural VSLBr chemistry would dominate Antarctic ozone seasonality before the end of the 21st century. This work suggests a large influence of biogenic bromine on the future Antarctic ozone layer.

  10. Local Structural and Electronic Changes Associated with the Bromination of YBCO: Charge Transfer and Cu-O Distortions

    Science.gov (United States)

    Dieng, Lamine M.; Tyson, Trevor A.; Croft, M.; Dogan, F.; Woicik, Joseph; Grow, James

    2000-03-01

    In order to understand the role of bromination in the recovery of superconductivity and metallic transport in underdoped YBCO, we have measured the local structural changes in brominated single crystal samples and compared them with normal samples. From the c-axis polarized near edge x-ray absorption measurements, we see, for the first time, direct evidence for the transfer of hole density into the Cu(2)O2 planes in brominated samples. The corresponding XAFS measurements show large changes in the c-axis Cu-O bond distribution. Measurements of the local structure about Ba and Br were also performed. No evidence was found for the incorporation of Br onto the O(4) sites as previously suggested by some authors. We were able to model the coordination of Br and found it to be consistent with BaBr2 as suggested by Fukuda et al. [1] and Potrepka et al. [2]. This work is supported by National Science Foundation Career Grant DMR-9733862. [1] Y. Fukuda et al. Phys. Rev. B 47, 418 (1993). [2] D. M. Potrepka et al., Phys. Rev. B 60, 10489 (1999).

  11. Formation potentials of bromate and brominated disinfection by-products in bromide-containing water by ozonation.

    Science.gov (United States)

    Lin, Tao; Wu, Shouke; Chen, Wei

    2014-12-01

    The ozonation involved in drinking water treatment raises issues of water quality security when the raw water contains bromide (Br(-)). Br(-) ions may be converted to bromate (BrO3 (-)) during ozonation and some brominated disinfection by-products (Br-DBPs) in the following chlorination. In this study, the effects of ozone (O3) dosage, contact time, pH, and Br(-) and ammonia (NH3-N) concentrations on the formation of BrO3 (-) and Br-DBPs have been investigated. The results show that decreasing the initial Br(-) concentration is an effective means of controlling the formation of BrO3 (-). When the concentration of Br(-) was lower than 100 μg/L, by keeping the ratio of O3 dosage to dissolved organic carbon (DOC) concentration at less than 1, BrO3 (-) production was effectively suppressed. The concentration of BrO3 (-) steadily increased with increasing O3 dosage at high Br(-) concentration (>900 μg/L). Additionally, a longer ozonation time increased the concentrations of BrO3 (-) and total organic bromine (TOBr), while it had less impact on the formation potentials of brominated trihalomethanes (Br-THMFP) and haloacetic acids (Br-HAAFP). Higher pH value and the presence of ammonia may lead to an increase in the formation potential of BrO3 (-) and Br-DBPs.

  12. Theoretical study of the reaction kinetics of atomic bromine with tetrahydropyran

    KAUST Repository

    Giri, Binod

    2015-02-12

    A detailed theoretical analysis of the reaction of atomic bromine with tetrahydropyran (THP, C5H10O) was performed using several ab initio methods and statistical rate theory calculations. Initial geometries of all species involved in the potential energy surface of the title reaction were obtained at the B3LYP/cc-pVTZ level of theory. These molecular geometries were reoptimized using three different meta-generalized gradient approximation (meta-GGA) functionals. Single-point energies of the stationary points were obtained by employing the coupled-cluster with single and double excitations (CCSD) and fourth-order Møller-Plesset (MP4 SDQ) levels of theory. The computed CCSD and MP4(SDQ) energies for optimized structures at various DFT functionals were found to be consistent within 2 kJ mol-1. For a more accurate energetic description, single-point calculations at the CCSD(T)/CBS level of theory were performed for the minimum structures and transition states optimized at the B3LYP/cc-pVTZ level of theory. Similar to other ether + Br reactions, it was found that the tetrahydropyran + Br reaction proceeds in an overall endothermic addition-elimination mechanism via a number of intermediates. However, the reactivity of various ethers with atomic bromine was found to vary substantially. In contrast with the 1,4-dioxane + Br reaction, the chair form of the addition complex (c-C5H10O-Br) for THP + Br does not need to undergo ring inversion to form a boat conformer (b-C4H8O2-Br) before the intramolecular H-shift can occur to eventually release HBr. Instead, a direct, yet more favorable route was mapped out on the potential energy surface of the THP + Br reaction. The rate coefficients for all relevant steps involved in the reaction mechanism were computed using the energetics of coupled cluster calculations. On the basis of the results of the CCSD(T)/CBS//B3LYP/cc-pVTZ level of theory, the calculated overall rate coefficients can be expressed as kov.,calc.(T) = 4.60 × 10

  13. Measurement-based modeling of bromine-induced oxidation of mercury above the Dead Sea

    Science.gov (United States)

    Tas, E.; Obrist, D.; Peleg, M.; Matveev, V.; Faïn, X.; Asaf, D.; Luria, M.

    2011-08-01

    Atmospheric mercury depletion events (AMDEs) outside the polar regions - driven by high levels of reactive bromine species (RBS) - were observed recently in the warm Dead Sea boundary layer. Efficient oxidation of gaseous elemental mercury (GEM) under temperate conditions by RBS was unexpected considering that the thermal back dissociation reaction of HgBr, a proposed key mechanism, is more than 2.5 orders of magnitude higher under Dead Sea temperatures compared with polar temperatures. The goal of this study was to improve understanding of RBS-mercury interactions using numerical simulations based on a comprehensive measurement campaign performed at the Dead Sea during summer 2009. Results demonstrate a high efficiency and central role of BrOx (i.e., Br + BrO) for AMDEs at the Dead Sea, with relative contributions for GEM depletion of more than ~90 %. BrO was found to be the dominant oxidant with relative contribution above 80 %. Best agreement between simulations and observations was achieved by applying rate constants for kHg+Br and kHg+BrO of 2.7×10-13 cm3 molecule-1 s-1 and 1.5 × 10-13 cm3 molecule-1 s-1, respectively - indicating that kHg+BrO is higher than most reported values and that BrO is a more efficient oxidant than Br in the ozone-rich atmosphere (i.e., for [BrO]/[Br] >2). This further explains why the efficiency of GEM oxidation by reactive bromine species at the Dead Sea doesn't critically depend on Br and, therefore, is comparable to the efficiency in polar regions even under much higher temperatures. These findings also support the hypothesis identified in a previous study, that Br-induced GEM depletion can be important above oceans in the mid-latitudes and tropics. In the presence of anthropogenic NO2, RBS activity can lead to enhanced NO3 formation, which then causes significant nighttime GEM depletion.

  14. Modelling the impact of chlorine and bromine emissions from large Plinian eruptions on ozone

    Science.gov (United States)

    Brenna, Hans; Krüger, Kirstin; Kutterolf, Steffen

    2016-04-01

    Large Plinian volcanic eruptions inject large amounts of atmosphere-relevant gases (e.g. S, Cl, Br) and materials into the stratosphere. If the eruption occurs in the tropics, it can have a global impact due to the dispersal through the large scale meridional overturning circulation. Most climate model studies concentrate on the sulfate aerosol effects on climate. In contrast, ozone-depletion initiated by volcanic halogens from tropical eruptions was believed to play an insignificant role for the global atmosphere, based on observations from the recent El Chichon and Pinatubo eruptions. New results regarding the halogen release by Plinian eruptions, as well as recent volcanic plume observations and model simulations facilitate now our investigation into what effect the combined chlorine and bromine emissions from large tropical eruptions have on ozone and the atmosphere in general. A complete halogen data set for the last 200 ka (Kutterolf et al., 2015), derived by the petrological method from paleo-eruptions of the Central American Volcanic Arc (CAVA), are used to force simulations with the advanced chemistry climate model WACCM (Whole Atmosphere Community Climate Model). The goal is to quantify the impact of volcanic halogens on the preindustrial atmosphere when the background chlorine levels were low compared to the present day with the main focus on stratospheric ozone. We carried out 5 model simulations assuming that 10% of the Cl and Br (9.51e+6 kg Br and 2.93e+9 kg Cl) emitted from the average CAVA eruption is injected into the tropical stratosphere during January. The model response reveals a global impact on the ozone layer affecting via radiation also atmospheric dynamics for more than 5 years. Given the current decline in anthropogenic chlorine, the results will become relevant for future halogen-rich explosive eruptions in the tropics. References: Kutterolf, S., T. Hansteen, A. Freundt, H. Wehrmann, K. Appel, K. Krüger, and W. Pérez (2015), Bromine

  15. Development of Zinc/Bromine Batteries for Load-Leveling Applications: Phase 1 Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Eidler, Phillip

    1999-07-01

    The Zinc/Bromine Load-Leveling Battery Development contract (No. 40-8965) was partitioned at the outset into two phases of equal length. Phase 1 started in September 1990 and continued through December 1991. In Phase 1, zinc/bromine battery technology was to be advanced to the point that it would be clear that the technology was viable and would be an appropriate choice for electric utilities wishing to establish stationary energy-storage facilities. Criteria were established that addressed most of the concerns that had been observed in the previous development efforts. The performances of 8-cell and 100-cell laboratory batteries demonstrated that the criteria were met or exceeded. In Phase 2, 100-kWh batteries will be built and demonstrated, and a conceptual design for a load-leveling plant will be presented. At the same time, work will continue to identify improved assembly techniques and operating conditions. This report details the results of the efforts carried out in Phase 1. The highlights are: (1) Four 1-kWh stacks achieved over 100 cycles, One l-kWh stack achieved over 200 cycles, One 1-kWh stack achieved over 300 cycles; (2) Less than 10% degradation in performance occurred in the four stacks that achieved over 100 cycles; (3) The battery used for the zinc loading investigation exhibited virtually no loss in performance for loadings up to 130 mAh/cm{sup 2}; (4) Charge-current densities of 50 ma/cm{sup 2} have been achieved in minicells; (5) Fourteen consecutive no-strip cycles have been conducted on the stack with 300+ cycles; (6) A mass and energy balance spreadsheet that describes battery operation was completed; (7) Materials research has continued to provide improvements in the electrode, activation layer, and separator; and (8) A battery made of two 50-cell stacks (15 kWh) was produced and delivered to Sandia National Laboratories (SNL) for testing. The most critical development was the ability to assemble a battery stack that remained leak free. The

  16. Temperature dependence of bromine activation due to reaction with ozone in a proxy for organic aerosols

    Science.gov (United States)

    Edebeli, Jacinta; Ammann, Markus; Gilgen, Anina; Eichler, Anja; Schneebeli, Martin; Bartels-Rausch, Thorsten

    2016-04-01

    The discovery of boundary layer ozone depletion events in the Polar Regions [1] and in the mid-latitudes [2], two areas of very different temperature regimes, begs the question of temperature dependence of reactions responsible for these observations [3]. These ODEs have been attributed to ozone reacting with halides leading to reactive halogens (halogen activation) of which bromide is extensively studied, R1 - R3 [4, 5] (R1 is a multiphase reaction). O3 + Br-→ O2 + OBr- (R1) OBr- + H+ ↔ HOBr (R2) HOBr + H+ + Br-→ Br2 + H2O (R3) Despite extensive studies of ozone-bromide interactions, the temperature dependence of bromine activation is not clear [3]. This limits parameterization of the involved reactions and factors in atmospheric models [3, 6]. Viscosity changes in the matrix (such as organic aerosols) due to temperature have been shown to influence heterogeneous reaction rates and products beyond pure temperature effect [7]. With the application of coated wall flow-tubes, the aim of this study is therefore to investigate the temperature dependence of bromine activation by ozone interaction while attempting to characterize the contributions of the bulk and surface reactions to observed ozone uptake. Citric acid is used in this study as a hygroscopically characterized matrix whose viscosity changes with temperature and humidity. Here, we present reactive ozone uptake measured between 258 and 289 K. The data show high reproducibility. Comparison of measured uptake with modelled bulk uptake at different matrix compositions (and viscosities) indicate that bulk reactive uptake dominates, but there are other factors which still need further consideration in the model. References 1. Barrie, L.A., et al., Nature, 1988. 334: p. 138 - 141. 2. Hebestreit, K., et al., Science, 1999. 283: p. 55-57. 3. Simpson, W.R., et al., Atmospheric Chemistry and Physics, 2007. 7: p. 4375 - 4418. 4. Haag, R.W. and J. Hoigné, Environ Sci Technol, 1983. 17: p. 261-267. 5. Oum, K.W., et

  17. Measurement-based modeling of bromine-induced oxidation of mercury above the Dead Sea

    Directory of Open Access Journals (Sweden)

    E. Tas

    2011-08-01

    Full Text Available Atmospheric mercury depletion events (AMDEs outside the polar regions – driven by high levels of reactive bromine species (RBS – were observed recently in the warm Dead Sea boundary layer. Efficient oxidation of gaseous elemental mercury (GEM under temperate conditions by RBS was unexpected considering that the thermal back dissociation reaction of HgBr, a proposed key mechanism, is more than 2.5 orders of magnitude higher under Dead Sea temperatures compared with polar temperatures. The goal of this study was to improve understanding of RBS-mercury interactions using numerical simulations based on a comprehensive measurement campaign performed at the Dead Sea during summer 2009.

    Results demonstrate a high efficiency and central role of BrOx (i.e., Br + BrO for AMDEs at the Dead Sea, with relative contributions for GEM depletion of more than ~90 %. BrO was found to be the dominant oxidant with relative contribution above 80 %. Best agreement between simulations and observations was achieved by applying rate constants for kHg+Br and kHg+BrO of 2.7×10−13 cm3 molecule−1 s−1 and 1.5 × 10−13 cm3 molecule−1 s−1, respectively – indicating that kHg+BrO is higher than most reported values and that BrO is a more efficient oxidant than Br in the ozone-rich atmosphere (i.e., for [BrO]/[Br] >2. This further explains why the efficiency of GEM oxidation by reactive bromine species at the Dead Sea doesn't critically depend on Br and, therefore, is comparable to the efficiency in polar regions even under much higher temperatures. These findings also support the hypothesis identified in a previous study, that Br-induced GEM depletion can be important above oceans in the mid-latitudes and tropics. In the presence of anthropogenic NO2, RBS activity can lead to enhanced NO3

  18. Brominated flame retardants in the Arctic. An overview of spatial and temporal trends

    Energy Technology Data Exchange (ETDEWEB)

    Wit, C. de [Institute of Applied Environmental Research, Stockholm (Sweden); Alaee, M.; Muir, D. [National Water Research Institute, Burlington, MA (United States)

    2004-09-15

    The Stockholm Convention on Persistent Organic Pollutants (POPs), which entered into force on May 17, 2004, includes wording that chemicals with the characteristics of POPs are those found in locations ''distant from sources'' and those for which ''monitoring data showing that long-range environmental transport of the chemical may have occurred''. Thus, the Arctic has become an important indicator region for assessment of persistence and bioaccumulation. The Arctic environment is well suited as a region in which to evaluate POPs. Some regions of thee Arctic, particularly the Barents Sea area north of Norway and western Russia are relatively close to source regions of POPs. Cold conditions favor persistence of POPs relative to temperate or tropical environments. The presence of fourth level carnivores (e.g. polar bears and seabirds), and storage of lipid as an energy source, make Arctic food webs vulnerable to bioaccumulative chemicals. Indigenous people in the Arctic utilizing a traditional diet, which is high in nutritionally beneficial fat, results in their elevated exposure to some POPs. The first indication that brominated flame retardants (BFRs) were reaching the Arctic was the detection by Jansson et al. of lower molecular weight polybrominated diphenyl ethers (PBDEs) in Svalbard Brunnichfs guillemots (130 ng/g lipid weight) and ringed seals (40 ng/g lw) collected in 1981. Whitefish collected from Lake Storvindeln in 1986, a pristine mountain lake in the Swedish mountains near Ammarnas, had {sigma}PBDE levels of 26 ng/g lw. Despite these early findings, only recently have the spatial and temporal trends of BFRs been studied in detail in the Arctic. The purpose of this paper is to review the new data on BFRs in the Arctic and assess whether this information supports the view that PBDEs and other BFRs of similar molecular weight are POPs and potential global pollutants. This review is based on a recent assessment of POPs

  19. Synoptic-scale meteorological control on reactive bromine production and ozone depletion in the Arctic boundary layer: 3-D simulation with the GEM-AQ model

    Directory of Open Access Journals (Sweden)

    K. Toyota

    2010-11-01

    Full Text Available Episodes of high bromine levels and surface ozone depletion in the springtime Arctic are simulated by an online air-quality model, GEM-AQ, with gas-phase and heterogeneous reactions of inorganic bromine species and a simple scheme of air-snowpack chemical interactions implemented for this study. Snowpack on sea ice is assumed to be the only source of bromine to the atmosphere and capable of converting relatively stable bromine species to photolabile Br2 via air-snowpack interactions. A "bromine explosion", by which Br retained in the snowpack is autocatalytically released to the atmosphere as a result of dry deposition of HOBr and BrONO2, is assumed to occur on young, first-year (FY sea ice (or its overlying snowpack, whereas the snowpack on old, multi-year (MY sea ice and over land is assumed only to recycle a part (but up to 100% of bromine reservoirs lost via dry deposition back to Br2. Model runs are performed for April 2001 at a horizontal resolution of approximately 100 km × 100 km in the Arctic. The model simulates temporal variations in surface ozone mixing ratios as observed at stations in the high Arctic and the synoptic-scale evolution of enhanced BrO column amounts ("BrO clouds" as seen from satellite reasonably well. The results strongly suggest: (1 a ubiquitous source of reactive bromine exists on the FY sea ice during the Arctic springtime; and (2 the timing of bromine release to the atmosphere is largely controlled by meteorological forcing on the transport of ozone to the near-surface air. Also, if the surface snowpack supplies most of the reactive bromine in the Arctic boundary layer, it should be capable of releasing reactive bromine at temperatures as high as −10 °C, particularly on the FY sea ice in the central and eastern Arctic Ocean. Dynamically-induced BrO column variability in the lowermost stratosphere appears to interfere with the use of satellite BrO column

  20. The mono - and sesquiterpene content of aphid-induced galls on Pistacia palaestina is not a simple reflection of their composition in intact leaves.

    Science.gov (United States)

    Rand, Karin; Bar, Einat; Ben-Ari, Matan; Lewinsohn, Efraim; Inbar, Moshe

    2014-06-01

    Pistacia palaestina Boiss. (Anacardiaceae), a sibling species of P. terebinthus also known as turpentine tree or terebinth tree, is common in the Levant region. The aphid Baizongia pistaciae L. manipulates the leaves of the plant to form large galls, which provide both food and protection for its developing offspring. We analyzed the levels and composition of mono-and sesquiterpenes in both leaves and galls of ten naturally growing trees. Our results show that monoterpene hydrocarbons are the main constituents of P. palaestina leaves and galls, but terpene levels and composition vary among trees. Despite this inter-tree variation, terpene levels and compositions in galls from different trees resemble each other more than the patterns displayed by leaves from the same trees. Generally, galls contain 10 to 60 fold higher total terpene amounts than leaves, especially of the monoterpenes α-pinene and limonene. Conversely, the leaves generally accumulate more sesquiterpenes, in particular E-caryophyllene, germacrene D and δ-cadinene, in comparison to galls. Our results clearly show that the terpene pattern in the galls is not a simple reflection of that of the leaves and suggest that aphids have a strong impact on the metabolism of their host plant, possibly for their own defense.

  1. Potent anti-inflammatory activity of sesquiterpene lactones from Neurolaena lobata (L.) R. Br. ex Cass., a Q'eqchi' Maya traditional medicine.

    Science.gov (United States)

    Walshe-Roussel, Brendan; Choueiri, Christine; Saleem, Ammar; Asim, Muhammd; Caal, Federico; Cal, Victor; Rojas, Marco Otarola; Pesek, Todd; Durst, Tony; Arnason, John Thor

    2013-08-01

    The widespread use of Neurolaena lobata (L.) R. Br. ex Cass. by Q'eqchi' Maya and indigenous healers throughout the Caribbean for inflammatory conditions prompted the study of the anti-inflammatory activity of this traditional medicine. The objectives of this study were to conduct a detailed ethnobotanical investigation of the uses of N. lobata by the Q'eqchi' Maya of Belize for a variety of inflammatory symptoms and to evaluate the in vitro anti-inflammatory activity of leaf extract and isolated sesquiterpene lactones. The crude 80% EtOH extract of N. lobata leaves administered at 100 μg/mL reduced LPS-stimulated TNF-α production in THP-1 monocytes by 72% relative to the stimulated vehicle control. Isolated sesquiterpene lactones, neurolenins B, C+D, lobatin B and 9α-hydroxy-8β-isovalerianyloxy-calyculatolide were more active (IC50=0.17-2.32 μM) than the positive control parthenolide (IC50=4.79 μM). The results provide a pharmacological and phytochemical basis for the traditional use of this leaf for inflammatory conditions.

  2. A new acorane sesquiterpene from Lysionotus pauciflorus%石吊兰全草中的一个新菖蒲烷类倍半萜

    Institute of Scientific and Technical Information of China (English)

    文庆发; 钟玉蛟; 苏雪会; 李聪颖; 刘静; 李延芳; 梁冰

    2013-01-01

    目的:研究石吊兰全草的化学成分.方法:采用硅胶、MCI等多种层析柱分离手段.运用NMR和MS等波谱技术鉴定化合物的结构.结果:从石吊兰全草中分离并鉴定了3个化合物:3,10-dihydroxyacoronene (1)、邻苯二甲酸二丁酯(2)和3',5'-二甲氧基4羟基顺式二苯乙烯(3).结论:化合物1为新的菖蒲烷类倍半萜,为首次从该属植物中分离得到的菖蒲烷类倍半萜类化合物.%AIM:To study the chemical constituents of the whole plant of Lysionotus pauciflorus.METHODS:Chromatographic separations on silica gel,Toyopearl HW-40F gel,and MCI gel were used to isolate the compounds.The structures were elucidated on the basis of spectral data.RESULTS:Three compounds were obtained and their structures were identified as 3,10-dihydroxyacoronene (1),bis(2-butylhexyl)phthalate (2) and 3,5-dimethoxy-4-hydroxy-trans-stilbene 0).CONCLUSION:Compound 1 is a new acorane sesquiterpene,this is the first report of acorane sesquiterpenes from the Lysionotus genus.

  3. Isolation and identification of two sesquiterpenes from flowers of Carthamus tinctorius%红花中2个倍半萜的分离和鉴定

    Institute of Scientific and Technical Information of China (English)

    李晓锋; 胡晓茹; 戴忠; 张燕; 梁宏; 林瑞超

    2012-01-01

    Objective To investigate the chemical constituents from the flowers of Carthamus tinctorius. Methods Two sesquiterpenes were isolated and purified by macroporous resin, silica gel, Sephadex LH-20, and preparative HPLC. Results Two sesquiterpenes were isolated from the water extract in the flowers of C. tinctorius and identified as (-)-methyl dihydrophaseate (1) and (-)-(9E)-methyl dihydrophaseate (2). Conclusion Compound 2 is a new compound named carthamate A.%目的 研究菊科植物红花Carthamus tinctorius的化学成分.方法 通过大孔吸附树脂、硅胶柱色谱、Sephadex LH-2O 色谱以及制备HPLC等方法进行分离纯化,并鉴定化合物的结构.结果 从红花水提部分得到2个倍半萜类化合物,通过波谱学方法分别鉴定为(-)-methyl dihydrophaseate(1)和(-)-(9E)-methyl dihydrophaseate (2).结论 其中化合物2为新化合物,命名为红花酯A.

  4. Assessing oestrogenic effects of brominated flame retardants hexabromocyclododecane and tetrabromobisphenol A on MCF-7 cells.

    Science.gov (United States)

    Dorosh, A; Děd, L; Elzeinová, F; Pěknicová, J

    2011-01-01

    Tetrabromobisphenol A (TBBPA) is the main flame retardant used in printed circuit boards and laminates. The human population is highly exposed to TBBPA as it is used in consumer electronics as well as office and communication equipment. The main use of hexabromocyclododecane (HBCD) is in insulation foam boards, which are widely used in the construction sector. Brominated flame retardants may possess endocrine disrupting activity and thus represent a threat to the environment, including humans and their reproduction. The aim of this work was to evaluate the oestrogenic effects of TBBPA and HBCD in vitro on MCF-7 cells. We used the proliferation test (E-screen assay) in MCF-7 breast cancer cells and reverse transcription quantitative polymerase chain reaction analysis of TFF1 gene expression to analyse oestrogenicity of the studied compounds. RT-qPCR has proved to be a fast and valuable molecular technique in gene expression quantification. HBCD but not TBBPA increased cell proliferation in MCF-7 cells and up-regulated TFF1 gene expression in a concentration-dependent manner. Anti-oestrogen ICI 182,780 inhibited up-regulation of TFF1 by HBCD. We have shown that HBCD displays oestrogen- like effects on MCF-7 cells. TBBPA, on the other hand, has not shown any oestrogenic effect mediated by the oestrogen receptor α.

  5. Crystal structure of a photobiologically active brominated angular pyranocoumarin: bromo-hydroxy-seselin

    Directory of Open Access Journals (Sweden)

    A. K. Bauri

    2017-03-01

    Full Text Available The title compound, C14H13BrO3 [systematic name: rac-(9S,10R-9-bromo-10-hydroxy-8,8-dimethyl-9,10-dihydro-2H,8H-pyrano[2,3-f]chromen-2-one], is a substituted pyranocoumarin, obtained by bromination of seselin [8,8-dimethyl-2H,8H-pyrano[2,3-f]chromen-2-one], which was isolated from the Indian herb Trachyspermum stictocarpum (Aajmod. The pyrano ring has a distorted half-chair conformation and its mean plane is inclined to the coumarin mean plane by 1.6 (2°. In the crystal, molecules are linked by pairs of O—H...O hydrogen bonds, forming inversion dimers with an R22(16 ring motif. The dimers stack along the a-axis direction and are linked by offset π–π interactions, forming columns [intercentroid distance = 3.514 (4 Å].

  6. In vitro screening of the endocrine disrupting potency of brominated flame retardants and their metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Hamers, T.; Kamstra, J.H. [Inst. for Environmental Studies (IVM), Amsterdam (Netherlands); Sonneveld, E. [BioDetection Systems (BDS), Amsterdam (Netherlands); Murk, A.J. [Wageningen Univ., Toxicology Group, Wageningen (Netherlands); Zegers, B.N.; Boon, J.P. [Royal Netherlands Inst. for Sea Research (NIOZ), Den Burg (Netherlands); Brouwer, A. [Umea Univ., Umea (Sweden)

    2004-09-15

    Substantial evidence is recently becoming available that brominated flame retardants (BFRs) are potential endocrine disruptors. The toxicological profile of BFRs, however, is too incomplete and insufficient to perform human and ecological risk assessment. To fill these gaps, the EU funded research program FIRE was started in December 2002. This program aims at the identification and toxicological characterization of the most potent and environmentally relevant BFRs and their possible risk for human and wildlife health. As part of a hazard identification approach, twenty seven BFRs have been selected within the framework of FIRE for pre-screening their endocrinedisrupting potencies. Selection of test compounds was based on a maximal variation in physicochemical characteristics of BFRs within the test set, allowing the establishment of quantitative structure-activity relationships (QSARs). In addition, environmental relevance (e.g. high production volumes and persistence) and availability for testing were used as selection criteria. BFRs were tested in seven different in vitro bioassays for their potency to interfere via estrogenic, thyroidal, androgenic, progestagenic, and Ah-receptor mediated pathways. Metabolisation rates of BFRs were determined using phenobarbital-induced rat liver microsomes. Finally, the endocrine disrupting potency of the metabolites was determined in the same in vitro bio-assays and compared to the potency of the parent compounds.

  7. A study of the presence of brominated flame retardants in Australian fauna

    Energy Technology Data Exchange (ETDEWEB)

    Symons, R.; Burniston, D.; Piro, N.; Stevenson, G.; Yates, A. [Australian Government Analytical Laboratories, Sydney (Australia)

    2004-09-15

    Brominated flame retardants, in particular polybrominated diphenyl ethers (PBDEs) gained prominence in the late nineties when Noren et al. reported an exponential increase in PBDE levels found in Swedish mothers milk over a quarter of a century period with an associated decrease in levels of dioxin-like compounds. PBDEs have since become exceptionally widely studied being detected in most environmental compartments and food as well as human tissues. Only limited information on the distribution if PBDEs is available for the Southern Hemisphere, however, elevated levels of PBDEs in pork fat were detected during the routine screening for organochlorine pesticide residues. More recently an investigation of breast milk for PBDE levels also demonstrated that levels were comparable with those in the Northern Hemisphere. BFRs are not manufactured in Australia but it has been estimated that over 500 tonnes are imported yearly of which 340 tonnes are PBDEs. In addition, the amount of PBDEs that are contained in imported articles used both in domestic and industrial applications is unknown. In this paper, we report levels of PBDEs in a range of different Australian fauna that show that these POPs have indeed become widely distributed both in terms of the types of the fauna but also the levels determined.

  8. Persistent brominated and chlorinated dioxin blood levels in a chemist. 35 years after dioxin exposure

    Energy Technology Data Exchange (ETDEWEB)

    Schecter, A.; Ryan, J.J. (Department of Preventive Medicine, College of Medicine, SUNY Health Science Center-Syracuse, NY (United States))

    1992-07-01

    This is the first report on occupational health hazards to dioxin chemists associated with laboratory exposure to 2,3,7,8-tetrabromodibenzodioxin (TBrDD), and further characterizes the human response to 2,3,7,8 tetrachlorodibenzodioxin (TCDD). In this case study the chemist was exposed on two separate occasions. In March 1956, after synthesizing 10 g of TBrDD, the chemist suffered from mild and transient chloracne of the neck and wrists; in September 1956, after synthesizing 16 g of TCDD, he suffered severe chloracne of the entire body, headaches, backache, and leg pain on exertion. His measured 2,3,7,8-TBrDD in 1991 was 625 parts per trillion (ppt) in whole blood lipid, 35 years after initial exposure and 18 ppt TCDD, an elevated level in comparison with the mean 2,3,7,8-TCDD level of 5 ppt in the US population. This is the first reported detection of a brominated dioxin in human tissue. The total halogenated dioxin body burden in September 1956 is estimated to have been between 13,005 ppt and 146,726 ppt. This amount can be considered to be, at least in this person, a strong chloracnegenic dose, and a dose causing human nervous system and muscular or circulatory system responses. This uptake demonstrates an occupational hazard to chemists and chemical workers, and the usefulness of human tissue dioxin measurements to document absorption.

  9. Brominated diphenyl ether levels. A comparison of tributary sediments versus biosolid material

    Energy Technology Data Exchange (ETDEWEB)

    Kolic, T.M.; MacPherson, K.A.; Reiner, E.J. [Ontario Ministry of the Environment, Laboratory Services Branch, Toronto, ON (Canada); Ho, T.; Kleywegt, S. [Ontario Ministry of the Environment, Standards Development Branch, Toronto, ON (Canada); Dove, A.; Marvin, C. [Environment Canada, Burlington, ON (Canada)

    2004-09-15

    PBDEs are persistent in the environment, have low water solubility and are known to have a tendency to bioaccumulate in wildlife and humans. There are 209 possible PBDE congeners. There has been concern over the bioaccumulation of these compounds since they have been found in mother's milk. Some of the brominated diphenyl ethers are known to metabolize into hydroxylated compounds and these metabolites are known to compete with and reduce thyroxine (T4) from binding to the thyroxine binding protein, transthyretin. This disrupts the thyroid hormone system interaction that has recently been notable amongst women in the form of hypothyroidism that can affect the fetus development in the form of neurodevelopmental deficits. There have been reports of estrogenic activities regarding PBDEs and their hydroxylated counterparts. Information such as this is indicative that PBDEs are endocrine disruptors. Due to their lipophilic nature, PBDEs have a high binding affinity to particulates and accumulate in sediments. Various reports on sediments and sludge type matrices have been reported in Austria, Switzerland, Netherlands and Canada. The following paper is a presentation of levels of PBDEs found in Tributary sediments and their comparison of levels to nearby biosolid sampling locations along Lake Ontario.

  10. QSAR classification models for the prediction of endocrine disrupting activity of brominated flame retardants.

    Science.gov (United States)

    Kovarich, Simona; Papa, Ester; Gramatica, Paola

    2011-06-15

    The identification of potential endocrine disrupting (ED) chemicals is an important task for the scientific community due to their diffusion in the environment; the production and use of such compounds will be strictly regulated through the authorization process of the REACH regulation. To overcome the problem of insufficient experimental data, the quantitative structure-activity relationship (QSAR) approach is applied to predict the ED activity of new chemicals. In the present study QSAR classification models are developed, according to the OECD principles, to predict the ED potency for a class of emerging ubiquitary pollutants, viz. brominated flame retardants (BFRs). Different endpoints related to ED activity (i.e. aryl hydrocarbon receptor agonism and antagonism, estrogen receptor agonism and antagonism, androgen and progesterone receptor antagonism, T4-TTR competition, E2SULT inhibition) are modeled using the k-NN classification method. The best models are selected by maximizing the sensitivity and external predictive ability. We propose simple QSARs (based on few descriptors) characterized by internal stability, good predictive power and with a verified applicability domain. These models are simple tools that are applicable to screen BFRs in relation to their ED activity, and also to design safer alternatives, in agreement with the requirements of REACH regulation at the authorization step.

  11. QSAR modeling and prediction of the endocrine-disrupting potencies of brominated flame retardants.

    Science.gov (United States)

    Papa, Ester; Kovarich, Simona; Gramatica, Paola

    2010-05-17

    In the European Union REACH regulation, the chemicals with particularly harmful behaviors, such as endocrine disruptors (EDs), are subject to authorization, and the identification of safer alternatives to these chemicals is required. In this context, the use of quantitative structure-activity relationships (QSAR) becomes particularly useful to fill the data gap due to the very small number of experimental data available to characterize the environmental and toxicological profiles of new and emerging pollutants with ED behavior such as brominated flame retardants (BFRs). In this study, different QSAR models were developed on different responses of endocrine disruption measured for several BFRs. The multiple linear regression approach was applied to a variety of theoretical molecular descriptors, and the best models, which were identified from all of the possible combinations of the structural variables, were internally validated for their performance using the leave-one-out (Q(LOO)(2) = 73-91%) procedure and scrambling of the responses. External validation was provided, when possible, by splitting the data sets in training and test sets (range of Q(EXT)(2) = 76-90%), which confirmed the predictive ability of the proposed equations. These models, which were developed according to the principles defined by the Organization for Economic Co-operation and Development to improve the regulatory acceptance of QSARs, represent a simple tool for the screening and characterization of BFRs.

  12. From Clothing to Laundry Water: Investigating the Fate of Phthalates, Brominated Flame Retardants, and Organophosphate Esters.

    Science.gov (United States)

    Saini, Amandeep; Thaysen, Clara; Jantunen, Liisa; McQueen, Rachel H; Diamond, Miriam L

    2016-09-01

    The accumulation of phthalate esters, brominated flame retardants (BFRs) and organophosphate esters (OPEs) by clothing from indoor air and transfer via laundering to outdoors were investigated. Over 30 days cotton and polyester fabrics accumulated 3475 and 1950 ng/dm(2) ∑5phthalates, 65 and 78 ng/dm(2) ∑10BFRs, and 1200 and 310 ng/dm(2) ∑8OPEs, respectively. Planar surface area concentrations of OPEs and low molecular weight phthalates were significantly greater in cotton than polyester and similar for BFRs and high molecular weight phthalates. This difference was significantly and inversely correlated with KOW, suggesting greater sorption of polar compounds to polar cotton. Chemical release from cotton and polyester to laundry water was >80% of aliphatic OPEs (log KOW phthalates (log KOW 4-6), and phthalates (log KOW > 8) and BFRs (log KOW > 6). These results support the hypothesis that clothing acts an efficient conveyer of soluble semivolatile organic compounds (SVOCs) from indoors to outdoors through accumulation from air and then release during laundering. Clothes drying could as well contribute to the release of chemicals emitted by electric dryers. The results also have implications for dermal exposure.

  13. Characterization of brominated flame retardants in construction and demolition waste components: HBCD and PBDEs.

    Science.gov (United States)

    Duan, Huabo; Yu, Danfeng; Zuo, Jian; Yang, Bo; Zhang, Yukui; Niu, Yongning

    2016-12-01

    The vast majority of construction material is inert and can be managed as nonhazardous. However, structures may have either been built with some environmentally unfriendly substances such as brominated flame retardants (BFRs), or have absorbed harmful elements such as heavy metals. This study focuses on end-of-life construction materials, i.e. construction and demolition (C&D) waste components. The aim was to characterize the concentration of extremely harmful substances, primarily BFRs, including hexabromocyclododecane (HBCD) and polybrominateddiphenyl ethers (PBDEs). Results revealed extremely high contents of HBCD and PBDEs in typical C&D waste components, particularly polyurethane foam materials. Policies should therefore be developed for the proper management of C&D waste, with priority for POP-containing debris. The first priority is to develop a classification system and procedures to separate out the harmful materials for more extensive processing. Additionally, identification and quantification of the environmental implications associated with dumping-dominated disposal of these wastes are required. Finally, more sustainable materials should be selected for use in the construction industry.

  14. Plasma brominated polymer particles as grafting substrate for thiol-terminated telomers.

    Science.gov (United States)

    Byström, Emil; Nordborg, Anna; Limé, Fredrik; Dinh, Ngoc Phuoc; Irgum, Knut

    2010-06-01

    A combined surface activation and "grafting to" strategy was developed to convert divinylbenzene particles into weak cation exchangers suitable for protein separation. The initial activation step was based on plasma modification with bromoform, which rendered the particles amenable to further reaction with nucleophiles by introducing Br to a surface content of 11.2 atom-%, as determined by X-ray photoelectron spectroscopy. Grafting of thiol-terminated glydicyl methacrylate telomers to freshly plasma activated surfaces was accomplished without the use of added initiator, and the grafting was verified both by reduction in bromine content and the appearance of sulfur-carbon linkages, showing that the surface grafts were covalently bonded. Following grafting the attached glydicyl methacrylate telomer tentacles were further modified by a two-step procedure involving hydrolysis to 2,3-hydroxypropyl groups and conversion of hydroxyl groups to carboxylate functionality by succinic anhydride. The final material was capable of baseline separating four model proteins in 3 min by gradient cation exchange chromatography in a fully aqueous eluent.

  15. [Aqueous iodine solutions as disinfectants: composition, stability, comparison with chlorine and bromine solution (author's transl)].

    Science.gov (United States)

    Gottardi, W

    1978-09-01

    The equilibrium concentrations of aqueous iodine solutions in dependence of the total concentration and the pH-value have been calculated with and without regard of the iodate formation. The values obtained by the latter methode enabled by application of the known rate law to calculate the initial rate of the iodate formation and to draw from this conclusions concerning the stability of iodine solutions. On the grounds of these calculations to aqueous iodine solutions in the concentration and pH-range which is relevant for disinfection (greater than 10(-5) M/l, pH 6--9) one can attribute a stability sufficient for the use in practice and - unlike chlorine and bromine solutions - a content of bactericidal "free halogene" which is higher and independent of the pH-value. The disinfecting action of the iodine cation (H2O+J) which is supposed to be very powerful can be neglected because of its low concentration (10(-3)--10(-6%) of the total concentration). Hypoiodic acid which has already been converted into iodate by disproportionation is as good as lost for the disinfection because of the extremely slow reverse reaction.

  16. Natural Oxidation of Bromide to Bromine in Evaporated Dead Sea Brines

    Science.gov (United States)

    Gavrieli, Ittai; Golan, Rotem; Lazar, Boaz; Baer, Gidi; Zakon, Yevgeni; Ganor, Jiwchar

    2016-04-01

    Highly evaporated Dead Sea brines are found in isolated sinkholes along the Dead Sea. Many of these brines reach densities of over 1.3 kg/L and pHDead Sea brine that drain into the sinkholes. The low pH and the reddish to brownish hue of these brines were an enigma until recently. Despite the rather high total alkalinity (TA) of the Dead Sea (3.826 mmol/kg) the pH of the Dead Sea brine is known to be slightly acidic with a value of ~6.3. In comparison, seawater with the same alkalinity would have a pH value well above 8.3, meaning that H+ activity is 100 fold lower than that of Dead Sea brine. In the present work we assess the apparent dissociation constant value of boric acid (K`B) for the Dead Sea brine and use it to explain the brine's low pH value. We then show that pH decreases further as the brine evaporates and salinity increases. Finally we explain the reddish hue of the hypersaline brines in the sinkholes as due to the presence of dissolved bromine. The latter is the product of oxidation of dissolved bromide, a process that is enabled by the low pH of the hypersaline brines and their high bromide concentration.

  17. Shuttle Environmental Assurance: Brominated Flame Retardants - Concerns, Drivers, Potential Impacts and Mitigation Strategies

    Science.gov (United States)

    Clark-Ingram, Marceia

    2010-01-01

    Brominated Flame Retardants (BFRs) are widely used in the manufacture of electrical and electronic components and as additives in formulations for foams, plastics and rubbers. The United States (US) and the European Union (EU)have increased regulation and monitoring of of targeted BFRs, such as Polybrominated Diphenyl Ethers (PBDEs) due to the bioaccumulative effects in humans and animals. In response, manufacturers and vendors of BFR-containing materials are changing flame-retardant additives, sometimes without notifying BFR users. In some instances, Deca-bromodiphenylether (Deca-BDE) and other families of flame retardants are being used as replacement flame retardants for penta-BDE and octa-BDE. The reformulation of the BFR-containing material typically results in the removal of the targeted PBDE and replacement with a non-PBDE chemical or non-targeted PBDE. Many users of PBDE -based materials are concerned that vendors will perform reformulation and not inform the end user. Materials performance such as flammability, adhesion , and tensile strength may be altered due to reformulation. The requalification of newly formulated materials may be required, or replacement materials may have to be identified and qualified. The Shuttle Enviornmental Assurance (SEA) team indentified a risk to the Space Shuttle Program associated with the possibility that targeted PBDEs may be replaced without notification. Resultant decreases in flame retardancy, Liquid Oxygen (LOX) compatibility, or material performance could have serious consequences.

  18. Simple and rapid quantification of brominated vegetable oil in commercial soft drinks by LC-MS.

    Science.gov (United States)

    Chitranshi, Priyanka; Gamboa da Costa, Gonçalo

    2016-12-15

    We report here a simple and rapid method for the quantification of brominated vegetable oil (BVO) in soft drinks based upon liquid chromatography-electrospray ionization mass spectrometry. Unlike previously reported methods, this novel method does not require hydrolysis, extraction or derivatization steps, but rather a simple "dilute and shoot" sample preparation. The quantification is conducted by mass spectrometry in selected ion recording mode and a single point standard addition procedure. The method was validated in the range of 5-25μg/mL BVO, encompassing the legal limit of 15μg/mL established by the US FDA for fruit-flavored beverages in the US market. The method was characterized by excellent intra- and inter-assay accuracy (97.3-103.4%) and very low imprecision [0.5-3.6% (RSD)]. The direct nature of the quantification, simplicity, and excellent statistical performance of this methodology constitute clear advantages in relation to previously published methods for the analysis of BVO in soft drinks.

  19. Brominated flame retardants (BFRs): A review on environmental contamination in China.

    Science.gov (United States)

    Yu, Gang; Bu, Qingwei; Cao, Zhiguo; Du, Xinming; Xia, Jing; Wu, Min; Huang, Jun

    2016-05-01

    Brominated flame retardants (BFRs) which were detected extensively in environmental and biota samples worldwide, have raised significant concerns during past decades for their persistence, bioaccumulation and potential toxicity to ecological environment and human health. In this paper, we have compiled and reviewed existing literature on the contamination status of BFRs in abiotic and biotic environments in China, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane, tetrabromobisphenol A and new BFRs. Temporal trends were also summarized and evaluated. Based on this review, it has been concluded that (1) high concentrations of PBDEs were generally related to the e-waste disposal processing, while the spatial distribution pattern of other BFRs was not necessarily in accordance with this; (2) extremely high concentrations of BFRs in indoor dust emphasized the importance of indoor contamination to human body burdens, while more work need to be done to confirm its contribution; (3) PBDEs in electronics dismantling workers were higher compared to the general population, indicating the occupational exposure should be of particular concern; (4) more data are now becoming available for BFRs in aquatic and terrestrial organisms not previously studied, while studies that consider the occurrence of BFRs in organisms of different trophic levels are still of urgent need for evaluating the fate of BFRs in the food web; and (5) limited data showed a decreasing trend for PBDEs, while more data on time trends of BFR contamination in various matrices and locations are still needed before the impact of regulation of BFRs can be assessed.

  20. Soil contamination by brominated flame retardants in open waste dumping sites in Asian developing countries.

    Science.gov (United States)

    Eguchi, Akifimi; Isobe, Tomohiko; Ramu, Karri; Tue, Nguyen Minh; Sudaryanto, Agus; Devanathan, Gnanasekaran; Viet, Pham Hung; Tana, Rouch Seang; Takahashi, Shin; Subramanian, Annamalai; Tanabe, Shinsuke

    2013-03-01

    In Asian developing countries, large amounts of municipal wastes are dumped into open dumping sites each day without adequate management. This practice may cause several adverse environmental consequences and increase health risks to local communities. These dumping sites are contaminated with many chemicals including brominated flame retardants (BFRs) such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs). BFRs may be released into the environment through production processes and through the disposal of plastics and electronic wastes that contain them. The purpose of this study was to elucidate the status of BFR pollution in municipal waste dumping sites in Asian developing countries. Soil samples were collected from six open waste dumping sites and five reference sites in Cambodia, India, Indonesia, Malaysia, and Vietnam from 1999 to 2007. The results suggest that PBDEs are the dominant contaminants in the dumping sites in Asian developing countries, whereas HBCD contamination remains low. Concentrations of PBDEs and HBCDs ranged from ND to 180 μg/kg dry wt and ND to 1.4 μg/kg dry wt, respectively, in the reference sites and from 0.20 to 430 μg/kg dry wt and ND to 2.5 μg/kg dry wt, respectively, in the dumping sites. Contamination levels of PBDEs in Asian municipal dumping sites were comparable with those reported from electronic waste dismantling areas in Pearl River delta, China.